Add optional/required extensions. (#117)

Co-authored-by: Mike English <mike.english@gmail.com>

.dockerignore

@@ -0,0 +1,3 @@
+target
+dev
+*.mp4

.editorconfig

@@ -8,3 +8,10 @@ insert_final_newline = true
 indent_style = tab
 indent_size = 4
 max_line_length = 120
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.yml]
+indent_style = space
+indent_size = 2

.github/logo.svg

@@ -0,0 +1,348 @@
+<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+	 width="100%" viewBox="0 0 1600 350" enable-background="new 0 0 1600 350" xml:space="preserve">
+<path fill="#00BF2D" opacity="1.000000" stroke="none"
+	d="
+M629.000000,251.175552
+	C696.998962,251.217285 764.499023,251.043793 831.996460,251.381424
+	C872.647339,251.584763 913.298706,252.386017 953.941528,253.292007
+	C982.745422,253.934082 1011.545044,254.980118 1040.328979,256.247833
+	C1072.095703,257.646881 1103.870239,259.095795 1135.590210,261.269958
+	C1172.600830,263.806732 1209.631958,266.431824 1246.516602,270.323273
+	C1295.623901,275.504242 1344.692993,281.265167 1393.597412,288.076874
+	C1427.318604,292.773712 1460.732422,299.676239 1494.286621,305.576050
+	C1495.344238,305.762024 1496.434937,305.760956 1497.510132,305.847107
+	C1497.821045,305.462891 1498.131958,305.078674 1498.442871,304.694458
+	C1488.217285,293.633759 1477.855469,282.693481 1467.882812,271.409302
+	C1465.925903,269.195099 1464.219971,265.425110 1464.695190,262.786316
+	C1465.133423,260.352997 1468.427979,257.132629 1470.885132,256.711182
+	C1473.629028,256.240570 1477.574585,257.756165 1479.722534,259.768066
+	C1486.266846,265.897827 1492.221802,272.660034 1498.360718,279.218506
+	C1505.749878,287.112610 1513.088989,295.053375 1520.459839,302.964661
+	C1521.367432,303.938873 1522.438965,304.774780 1523.260864,305.812347
+	C1527.773071,311.508759 1525.604370,317.245026 1518.569824,318.799347
+	C1514.398804,319.720978 1510.317749,321.054749 1506.204834,322.233215
+	C1492.317871,326.212219 1478.444458,330.239075 1464.535034,334.137756
+	C1463.163330,334.522247 1461.333008,334.640198 1460.143799,334.037231
+	C1457.149780,332.519318 1454.400635,330.518280 1451.553345,328.710907
+	C1453.454956,326.675415 1454.985962,323.813782 1457.329102,322.762604
+	C1463.820068,319.850586 1470.642944,317.674500 1477.350464,315.251526
+	C1478.867554,314.703461 1480.448853,314.333069 1481.939453,313.325989
+	C1472.812378,312.558197 1463.662720,311.992706 1454.562866,310.980316
+	C1435.890259,308.902893 1417.238159,306.635834 1398.588989,304.354828
+	C1376.142456,301.609375 1353.720581,298.658081 1331.263916,295.999207
+	C1308.310791,293.281616 1285.343750,290.661316 1262.354004,288.277039
+	C1243.162964,286.286713 1223.942993,284.541443 1204.712646,282.972260
+	C1179.338867,280.901733 1153.949097,279.014832 1128.553101,277.235474
+	C1115.102783,276.293091 1101.631714,275.571259 1088.158325,275.050995
+	C1040.065796,273.194092 991.970093,271.413574 943.871704,269.715393
+	C924.729553,269.039551 905.579163,268.302917 886.429138,268.194153
+	C777.940491,267.577850 669.451111,267.074097 560.961487,266.667938
+	C464.478882,266.306732 367.991150,266.582184 271.514618,265.650635
+	C228.399628,265.234344 185.303329,262.628845 142.205185,260.855164
+	C126.569107,260.211700 110.952034,259.103943 95.327812,258.182037
+	C94.409203,258.127808 93.504318,257.841095 92.610275,256.814972
+	C93.799576,256.692017 94.988075,256.470398 96.178314,256.460632
+	C124.171005,256.231537 152.166306,256.187103 180.156113,255.771332
+	C210.804214,255.316101 241.445053,254.377655 272.093018,253.907425
+	C324.735779,253.099701 377.379822,252.239914 430.026611,251.863953
+	C496.182678,251.391495 562.342041,251.383850 629.000000,251.175552
+z"/>
+<path fill="#FBFBFC" opacity="1.000000" stroke="none"
+	d="
+M1136.531250,75.468430
+	C1149.502686,89.464615 1158.312866,105.204132 1161.071167,123.944977
+	C1164.256714,145.588089 1155.058838,161.365723 1137.358032,172.860504
+	C1132.915649,175.745377 1128.063721,177.999420 1123.526367,180.474442
+	C1126.513184,187.666153 1129.579590,195.049347 1132.855957,202.938431
+	C1123.931519,204.148102 1115.508179,202.346771 1110.577148,195.110870
+	C1105.483032,187.635696 1100.227417,187.258179 1092.027954,188.385681
+	C1070.494629,191.346680 1049.619141,188.256668 1031.786011,174.742630
+	C999.943604,150.612198 998.185486,104.367447 1027.705688,76.309776
+	C1039.444458,65.152596 1052.978394,57.629692 1069.411377,55.724426
+	C1075.942505,54.967213 1082.346558,52.011589 1088.812012,51.999477
+	C1108.218750,51.963127 1123.192627,61.870239 1136.531250,75.468430
+M1081.841064,145.525299
+	C1080.419556,139.547165 1081.585205,135.960693 1085.617065,133.906250
+	C1089.598022,131.877777 1093.365967,133.214371 1097.057617,138.187378
+	C1098.537598,140.181168 1099.774536,142.367310 1101.005127,144.532379
+	C1104.915039,151.411697 1108.770020,158.322296 1113.107422,166.041336
+	C1120.483521,162.215363 1127.704468,159.163391 1134.170044,154.951767
+	C1143.576294,148.824509 1148.202881,139.659027 1146.197388,128.397034
+	C1141.447144,101.723297 1125.503296,83.583786 1101.300049,72.604919
+	C1092.501587,68.613853 1082.749512,66.282639 1073.111206,68.667519
+	C1058.141846,72.371498 1045.922119,80.847488 1036.339478,92.972885
+	C1019.910889,113.760803 1022.760925,144.436249 1042.867920,159.496338
+	C1057.771973,170.659393 1075.039429,171.245407 1092.828979,169.646286
+	C1089.109741,161.592758 1085.579102,153.947586 1081.841064,145.525299
+z"/>
+<path fill="#FAFAFB" opacity="1.000000" stroke="none"
+	d="
+M163.409271,97.601189
+	C159.556641,82.961777 155.850479,68.708122 152.144302,54.454468
+	C151.539719,54.494175 150.935135,54.533886 150.330551,54.573593
+	C150.238388,56.162678 150.003922,57.758244 150.075943,59.339851
+	C150.856064,76.471855 152.018768,93.594795 152.371094,110.734718
+	C152.574844,120.646263 152.286118,130.707367 150.768463,140.475784
+	C149.239716,150.315628 139.963211,153.317551 133.007675,146.116348
+	C126.618286,139.501297 120.986832,131.806183 116.531418,123.751656
+	C109.635605,111.285385 104.017014,98.112022 97.877350,85.228714
+	C97.052658,83.498199 96.347321,81.710808 95.109352,78.844490
+	C93.638824,92.596100 92.969818,105.222824 90.824066,117.593391
+	C86.344818,143.416916 81.103470,169.108627 76.107986,194.841431
+	C75.765762,196.604324 75.335861,198.819595 74.120293,199.838791
+	C72.050568,201.574173 68.985298,203.912735 66.967407,203.420258
+	C64.912872,202.918823 62.141987,199.226456 62.258987,197.071014
+	C62.652668,189.818619 63.983761,182.589264 65.329239,175.421097
+	C72.090233,139.401337 76.428711,103.108971 78.109642,66.492729
+	C78.467834,58.690132 79.265854,50.906723 79.913078,43.118782
+	C80.302116,38.437618 82.696655,35.136398 87.391167,34.368179
+	C92.028061,33.609390 95.074997,36.559422 96.790001,40.362938
+	C101.086494,49.891605 105.364403,59.453991 109.039825,69.232117
+	C116.894081,90.127693 125.350204,110.678284 138.704605,128.815002
+	C139.493042,129.885788 140.304932,130.941299 141.151642,131.966141
+	C141.447189,132.323883 141.880798,132.567551 143.146240,133.577560
+	C143.830902,128.312241 145.004654,123.667191 144.932312,119.041618
+	C144.690186,103.559769 143.727631,88.087433 143.584473,72.606430
+	C143.492386,62.647972 144.171692,52.666691 144.934692,42.728611
+	C145.096863,40.616306 147.122131,38.647049 148.289017,36.611893
+	C150.504868,38.044456 153.744263,38.964149 154.762741,40.996700
+	C159.663269,50.776634 164.578201,60.630810 168.352448,70.876930
+	C176.551086,93.134140 184.218704,115.592049 191.787308,138.074326
+	C196.154129,151.045807 197.230148,164.420029 194.373154,178.764542
+	C193.094727,177.356552 191.899033,176.219727 190.911789,174.924072
+	C182.707550,164.156830 177.968872,151.777100 174.438080,138.884979
+	C170.711868,125.279350 167.175201,111.621811 163.409271,97.601189
+z"/>
+<path fill="#FBFBFB" opacity="1.000000" stroke="none"
+	d="
+M1318.623291,213.559036
+	C1326.593018,211.154846 1334.216919,208.927917 1340.603882,207.062286
+	C1344.129639,171.296021 1347.595703,136.135696 1351.028809,101.308739
+	C1342.915527,102.577072 1334.153809,104.093391 1325.344238,105.241043
+	C1322.425903,105.621231 1319.333374,105.347610 1316.410278,104.847801
+	C1312.129639,104.115845 1309.018921,100.919800 1309.508179,96.984612
+	C1309.856445,94.183403 1312.863647,90.051605 1315.391113,89.441330
+	C1338.757202,83.799500 1362.226318,78.544655 1385.787476,73.779846
+	C1391.750977,72.573822 1398.291504,72.711571 1404.852295,76.730232
+	C1392.971924,90.214096 1376.451050,92.201271 1360.660645,98.128868
+	C1369.758423,132.311966 1362.319824,166.812546 1360.679443,201.668655
+	C1369.330933,200.256683 1377.375122,198.362335 1385.510742,197.808289
+	C1391.530029,197.398361 1397.741577,198.331177 1403.728638,199.425430
+	C1408.042236,200.213837 1408.640625,202.562515 1405.111938,204.918213
+	C1399.963013,208.355545 1394.470825,212.122604 1388.599731,213.484131
+	C1366.290161,218.657791 1343.783691,222.992584 1321.318115,227.476761
+	C1315.322754,228.673447 1310.937744,226.695831 1309.865845,223.001495
+	C1308.736206,219.107834 1311.269165,216.317764 1318.623291,213.559036
+z"/>
+<path fill="#FBFBFB" opacity="1.000000" stroke="none"
+	d="
+M1287.844727,130.118118
+	C1294.262207,144.747940 1300.462524,159.051559 1306.968994,173.214539
+	C1310.164185,180.170013 1310.593384,186.843002 1306.737915,194.156265
+	C1300.050781,192.227844 1294.365967,189.112549 1290.990601,182.952011
+	C1286.840210,175.377365 1283.038086,167.611832 1279.091431,159.925705
+	C1278.517090,158.807190 1277.975586,157.671844 1277.343994,156.393036
+	C1274.793579,161.344620 1272.824829,166.260513 1269.945923,170.568115
+	C1256.856689,190.153320 1232.661377,197.443680 1213.129883,187.786453
+	C1199.905762,181.247833 1192.978516,169.579681 1189.343994,156.023926
+	C1183.894531,135.699097 1183.905884,114.917877 1185.908691,94.103676
+	C1186.309937,89.935753 1188.117554,86.130157 1192.624146,86.199341
+	C1197.307983,86.271255 1199.271851,90.129578 1199.567261,94.530823
+	C1200.413452,107.143066 1200.622437,119.827904 1202.148315,132.354294
+	C1203.181030,140.831161 1205.151001,149.424347 1208.237061,157.369156
+	C1213.500000,170.918060 1223.648682,176.521271 1238.000244,173.992706
+	C1253.198120,171.315033 1265.452393,163.931900 1270.945557,148.483078
+	C1271.809204,146.054733 1271.923828,142.860641 1271.133911,140.426361
+	C1266.598022,126.445602 1263.218018,112.255936 1262.750122,97.529289
+	C1262.626465,93.635056 1262.824219,89.307877 1264.435791,85.922951
+	C1265.601440,83.474945 1269.326782,80.929306 1271.949707,80.887558
+	C1274.252197,80.850899 1277.810791,83.795891 1278.690063,86.200768
+	C1280.482788,91.103928 1281.747070,96.555244 1281.603394,101.735649
+	C1281.326904,111.707245 1284.505249,120.671661 1287.844727,130.118118
+z"/>
+<path fill="#FBFBFB" opacity="1.000000" stroke="none"
+	d="
+M342.167328,116.560349
+	C342.607605,128.632126 346.551636,139.397873 349.744049,150.408463
+	C353.743408,164.202164 356.755859,178.281998 360.194305,192.238327
+	C359.493927,192.600998 358.793518,192.963654 358.093140,193.326324
+	C353.282837,188.887039 348.472504,184.447754 343.396149,179.762924
+	C342.712463,181.693939 342.026672,183.621872 341.347015,185.551987
+	C336.777466,198.529419 325.178802,206.497086 313.291534,204.823074
+	C301.280579,203.131653 292.968079,193.438995 292.280273,179.400070
+	C291.788818,169.369019 294.304321,159.899078 300.247253,151.620850
+	C307.615692,141.356949 316.363403,140.147446 328.292542,147.976822
+	C327.980743,145.991440 327.800507,144.420532 327.481873,142.878204
+	C322.446899,118.508255 316.997528,94.213493 312.583099,69.732010
+	C311.228119,62.217468 312.484894,54.181606 312.943695,46.407955
+	C313.253174,41.164368 317.112122,38.454212 321.743195,37.473629
+	C326.174896,36.535255 329.411072,39.629780 330.726501,43.192245
+	C333.578522,50.916084 336.623993,58.818966 337.689606,66.899292
+	C339.840698,83.211403 340.724609,99.690636 342.167328,116.560349
+M309.993713,172.914719
+	C309.980682,175.578445 309.777679,178.257812 309.995667,180.902496
+	C310.400360,185.813385 313.078979,188.762299 318.044159,189.620300
+	C326.737244,191.122452 338.776581,180.273026 338.102356,171.451462
+	C338.053619,170.813690 337.791229,170.173080 337.535583,169.573257
+	C335.144562,163.962906 332.733246,158.361206 330.440308,153.019058
+	C328.357971,153.635178 326.326569,154.664383 324.247040,154.773209
+	C317.316254,155.135880 313.925201,159.362122 311.976410,165.337982
+	C311.257599,167.542145 310.705719,169.800751 309.993713,172.914719
+z"/>
+<path fill="#FBFBFB" opacity="1.000000" stroke="none"
+	d="
+M1513.002930,170.004578
+	C1494.165283,176.457748 1475.004761,181.331024 1454.884521,179.858139
+	C1440.411255,178.798630 1427.254639,173.872086 1416.528076,163.787704
+	C1401.059082,149.244965 1397.860962,127.149376 1408.758911,108.019783
+	C1421.130615,86.303116 1439.984131,73.373810 1464.666260,69.665749
+	C1469.809692,68.893051 1475.527588,70.309135 1480.654785,71.821388
+	C1482.884399,72.479012 1484.290283,75.929276 1486.070312,78.111168
+	C1483.802979,79.326584 1481.623413,81.378937 1479.254517,81.627686
+	C1456.195435,84.049095 1439.207275,96.295998 1426.711914,114.875160
+	C1416.032837,130.753922 1421.064209,147.970795 1438.437866,155.968704
+	C1453.955200,163.112061 1470.665405,166.288895 1487.626831,167.681854
+	C1495.733643,168.347626 1503.915161,168.104095 1512.499268,168.560028
+	C1512.958008,169.233292 1512.980469,169.618927 1513.002930,170.004578
+z"/>
+<path fill="#FBFBFB" opacity="1.000000" stroke="none"
+	d="
+M239.201996,130.145264
+	C248.979431,126.278221 258.399506,125.809898 267.565765,130.571045
+	C279.664764,136.855499 281.621063,148.989212 271.858185,158.454910
+	C261.869293,168.139725 249.079178,173.241089 236.618393,178.784348
+	C235.295547,179.372803 233.914032,179.829407 231.761765,180.652298
+	C242.173447,194.611206 255.143845,202.371750 273.385498,202.476227
+	C265.802246,207.568604 258.215027,210.398682 249.902466,210.877014
+	C231.864685,211.914963 216.718536,199.375671 212.102386,179.896667
+	C207.268417,159.498505 217.625748,140.263992 239.201996,130.145264
+M242.810928,159.339478
+	C250.042633,155.146423 257.274323,150.953354 265.286041,146.308029
+	C252.233353,139.755737 233.610580,150.564499 231.300339,164.740128
+	C235.050735,163.017868 238.613678,161.381699 242.810928,159.339478
+z"/>
+<path fill="#FBFBFB" opacity="1.000000" stroke="none"
+	d="
+M624.167725,142.316818
+	C627.976257,136.513885 630.969482,130.369003 635.563232,125.851997
+	C641.728455,119.789795 648.274597,120.355034 655.143066,125.560020
+	C655.977478,126.192337 657.476501,126.451340 658.519653,126.219101
+	C663.589783,125.090317 668.150696,126.073051 672.096252,129.341476
+	C682.107605,137.634766 686.472229,148.416443 684.693054,161.209671
+	C683.076294,172.835236 674.802002,179.983856 661.441101,182.456970
+	C644.284973,185.632584 627.357971,176.376709 623.780945,160.850235
+	C622.462158,155.125778 623.890076,148.768494 624.167725,142.316818
+M649.053528,141.777878
+	C647.990417,141.277863 646.927307,140.777863 645.846741,140.269623
+	C635.844177,152.499466 640.121277,164.773209 655.520142,167.670135
+	C657.451111,168.033401 659.509094,168.111038 661.461914,167.897369
+	C668.356323,167.143036 671.814758,162.153915 670.620911,155.275330
+	C669.067078,146.321915 662.716980,141.557297 655.674438,137.376404
+	C653.544861,138.765686 651.604553,140.031464 649.053528,141.777878
+z"/>
+<path fill="#FAFAFB" opacity="1.000000" stroke="none"
+	d="
+M772.803223,161.083405
+	C770.535583,148.230927 774.162292,137.747620 784.392395,130.386093
+	C794.918396,122.811592 806.447388,122.673988 817.790405,128.736755
+	C825.595703,132.908661 827.257202,141.721008 821.407837,148.616196
+	C813.783691,157.603333 803.725098,160.429779 792.228149,158.507355
+	C791.281921,158.349136 790.339722,158.167206 788.353943,157.807709
+	C797.509705,171.729874 810.399170,176.276154 824.957275,177.567291
+	C820.938843,183.615295 807.955444,188.047073 798.095459,186.049118
+	C784.516785,183.297653 776.255554,174.859680 772.803223,161.083405
+M809.558899,135.862030
+	C798.588806,134.269241 792.872375,137.437286 789.616760,147.077301
+	C798.363342,144.511520 808.040649,144.867493 815.703674,137.563873
+	C813.464600,136.878754 811.919861,136.406067 809.558899,135.862030
+z"/>
+<path fill="#FAFAFA" opacity="1.000000" stroke="none"
+	d="
+M738.921509,145.878479
+	C743.540833,140.195419 747.723938,134.589798 752.464417,129.503799
+	C755.873108,125.846649 758.645569,126.472183 759.393555,131.253906
+	C760.107605,135.818985 760.240601,141.074524 758.657593,145.285431
+	C754.134583,157.316803 746.475342,167.422684 736.250244,175.312180
+	C726.499817,182.835358 719.246155,181.199112 712.776489,170.630692
+	C705.711975,159.090546 703.272278,146.248688 702.279846,133.068970
+	C702.142761,131.247955 704.191101,129.262344 705.227661,127.352921
+	C706.951050,128.577072 709.394531,129.419556 710.279236,131.088379
+	C715.386841,140.722626 720.126099,150.552109 725.727478,161.795441
+	C730.797424,155.703156 734.760620,150.940750 738.921509,145.878479
+z"/>
+<path fill="#F9F9FA" opacity="1.000000" stroke="none"
+	d="
+M467.165802,147.065536
+	C472.151550,142.035843 476.259644,141.605576 479.298157,147.278534
+	C485.218536,158.331879 490.264221,169.873840 495.226379,181.405243
+	C496.375275,184.075195 495.731476,187.516586 495.914032,190.627243
+	C485.614532,190.666885 480.080963,186.271896 472.886597,173.218597
+	C468.179077,176.379196 463.730988,180.169205 458.632111,182.586426
+	C452.203400,185.634048 445.446136,185.023941 440.131805,179.805389
+	C434.910126,174.677826 434.783051,168.194519 437.191345,161.708786
+	C441.004791,151.438919 449.126953,146.544067 459.485138,145.024109
+	C461.408630,144.741852 463.548248,145.932449 465.833313,147.078125
+	C465.015228,148.906235 464.032562,150.185135 462.873444,151.276627
+	C459.494141,154.458847 455.682281,157.263580 452.731049,160.793991
+	C450.146057,163.886307 447.220856,167.825180 450.510193,171.991028
+	C453.720581,176.056946 458.457642,175.628967 462.928589,174.324921
+	C464.630066,173.828644 466.167450,172.678284 467.693420,171.692612
+	C470.238068,170.048920 470.982910,168.047455 469.733948,164.947800
+	C467.439240,159.252930 465.345367,153.405151 467.165802,147.065536
+z"/>
+<path fill="#FAFAFA" opacity="1.000000" stroke="none"
+	d="
+M857.086792,179.194427
+	C850.600952,181.854446 846.328918,179.966370 844.737183,173.525055
+	C843.466309,168.382309 842.729065,163.088470 842.050903,157.823563
+	C841.268188,151.747162 840.628784,145.639175 840.283630,139.524780
+	C840.096436,136.210342 838.479553,131.607040 844.893616,131.885284
+	C845.673340,131.919128 846.687500,130.233536 847.330750,129.184052
+	C859.965393,108.569351 884.028992,113.000961 896.941345,124.514656
+	C891.695740,125.275612 886.481995,125.892799 881.320496,126.805115
+	C860.490051,130.486984 855.529175,139.071472 858.402710,160.841064
+	C858.792725,163.796036 859.318726,166.771271 860.180298,169.616455
+	C861.346863,173.468765 860.345154,176.458069 857.086792,179.194427
+z"/>
+<path fill="#FAFBFB" opacity="1.000000" stroke="none"
+	d="
+M380.792236,102.062325
+	C380.235046,99.406120 379.549133,97.142342 379.399231,94.843613
+	C378.919006,87.477249 380.686188,84.940620 388.542725,81.606430
+	C387.097687,80.077728 385.776917,78.680450 384.315948,77.134903
+	C388.208435,72.881897 393.210083,73.350266 398.035309,74.871124
+	C409.622528,78.523277 416.637024,95.479935 411.179871,106.306816
+	C408.505524,111.612694 404.068512,114.634636 398.109192,114.996391
+	C391.277008,115.411140 386.330261,112.096550 382.769348,106.511284
+	C381.974762,105.264984 381.520081,103.801987 380.792236,102.062325
+z"/>
+<path fill="#F9F9FA" opacity="1.000000" stroke="none"
+	d="
+M391.399902,139.195312
+	C393.872406,142.425400 396.737183,145.267319 397.940125,148.692810
+	C402.384827,161.349411 406.280365,174.198837 410.381775,186.975983
+	C410.483490,187.292831 410.608765,187.605957 410.672058,187.930756
+	C411.964386,194.566360 409.668182,199.769592 404.835266,201.174149
+	C400.390320,202.465942 395.465637,199.427383 393.409119,193.040955
+	C391.333191,186.594208 389.840393,179.908524 388.701935,173.223679
+	C387.197479,164.389755 386.045258,155.477432 385.207855,146.555038
+	C384.677216,140.901108 386.365387,139.208511 391.399902,139.195312
+z"/>
+<path fill="#058B2C" opacity="1.000000" stroke="none"
+	d="
+M80.124115,257.917877
+	C73.365936,257.403900 67.078743,256.905029 60.791542,256.406158
+	C60.831306,256.228943 60.871075,256.051727 60.910839,255.874512
+	C70.181015,255.874512 79.451187,255.874512 88.721367,255.874512
+	C88.736588,256.560669 88.751801,257.246826 88.767021,257.932983
+	C86.043045,257.932983 83.319061,257.932983 80.124115,257.917877
+z"/>
+<path fill="#A4A7AE" opacity="1.000000" stroke="none"
+	d="
+M1513.363892,170.057541
+	C1512.980469,169.618927 1512.958008,169.233292 1512.905029,168.553741
+	C1514.441284,168.074600 1516.007935,167.889343 1517.574707,167.704102
+	C1517.666748,168.004990 1517.758911,168.305893 1517.851074,168.606781
+	C1516.475708,169.108032 1515.100220,169.609268 1513.363892,170.057541
+z"/>
+</svg>

.github/workflows/check.yml

@@ -1,29 +0,0 @@
-name: moq.rs
-
-on:
-  pull_request:
-    branches: [ "main" ]
-
-env:
-  CARGO_TERM_COLOR: always
-
-jobs:
-  check:
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v3
-
-    - name: toolchain
-      uses: actions-rust-lang/setup-rust-toolchain@v1
-      with:
-        components: clippy, rustfmt
-
-    - name: test
-      run: cargo test --verbose
-
-    - name: clippy
-      run: cargo clippy
-
-    - name: fmt
-      run: cargo fmt --check

.github/workflows/main.yml

@@ -0,0 +1,65 @@
+name: main
+
+on:
+  push:
+    branches: ["main"]
+
+env:
+  REGISTRY: docker.io
+  IMAGE: kixelated/moq-rs
+  IMAGE-PUB: kixelated/moq-pub
+  SERVICE: api # Restart the API service TODO and relays
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+      id-token: write
+
+    # Only one release at a time and cancel prior releases
+    concurrency:
+      group: release
+      cancel-in-progress: true
+
+    steps:
+      - uses: actions/checkout@v3
+
+      # I'm paying for Depot for faster ARM builds.
+      - uses: depot/setup-action@v1
+
+      - uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      # Build and push Docker image with Depot
+      - uses: depot/build-push-action@v1
+        with:
+          project: r257ctfqm6
+          context: .
+          push: true
+          tags: ${{env.REGISTRY}}/${{env.IMAGE}}
+          platforms: linux/amd64,linux/arm64
+
+      # Same, but include ffmpeg for publishing BBB
+      - uses: depot/build-push-action@v1
+        with:
+          project: r257ctfqm6
+          context: .
+          push: true
+          target: moq-pub # instead of the default target
+          tags: ${{env.REGISTRY}}/${{env.IMAGE-PUB}}
+          platforms: linux/amd64,linux/arm64
+
+      # Log in to GCP
+      - uses: google-github-actions/auth@v1
+        with:
+          credentials_json: ${{ secrets.GCP_SERVICE_ACCOUNT_KEY }}
+
+      # Deploy to cloud run
+      - uses: google-github-actions/deploy-cloudrun@v1
+        with:
+          service: ${{env.SERVICE}}
+          image: ${{env.REGISTRY}}/${{env.IMAGE}}

.github/workflows/pr.yml

@@ -0,0 +1,28 @@
+name: pr
+
+on:
+  pull_request:
+    branches: ["main"]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+
+      # Install Rust with clippy/rustfmt
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          components: clippy, rustfmt
+
+      # Make sure u guys don't write bad code
+      - run: cargo test --verbose
+      - run: cargo clippy --no-deps
+      - run: cargo fmt --check
+
+      # Check for unused dependencies
+      - uses: bnjbvr/cargo-machete@main

.gitignore

@@ -1,3 +1,4 @@
 .DS_Store
 target/
 logs/
+*.mp4

Cargo.toml

@@ -1,2 +1,3 @@
 [workspace]
-members = ["moq-transport", "moq-quinn", "moq-warp"]
+members = ["moq-transport", "moq-relay", "moq-pub", "moq-api"]
+resolver = "2"

Dockerfile

@@ -0,0 +1,39 @@
+FROM rust:latest as builder
+
+# Create a build directory and copy over all of the files
+WORKDIR /build
+COPY . .
+
+# Reuse a cache between builds.
+# I tried to `cargo install`, but it doesn't seem to work with workspaces.
+# There's also issues with the cache mount since it builds into /usr/local/cargo/bin, and we can't mount that without clobbering cargo itself.
+# We instead we build the binaries and copy them to the cargo bin directory.
+RUN --mount=type=cache,target=/usr/local/cargo/registry \
+    --mount=type=cache,target=/build/target \
+    cargo build --release && cp /build/target/release/moq-* /usr/local/cargo/bin
+
+# Special image for moq-pub with ffmpeg and a publish script included.
+FROM rust:latest as moq-pub
+
+# Install required utilities and ffmpeg
+RUN apt-get update && \
+    apt-get install -y ffmpeg wget
+
+# Copy the publish script into the image
+COPY deploy/publish.sh /usr/local/bin/publish
+
+# Copy the compiled binary
+COPY --from=builder /usr/local/cargo/bin/moq-pub /usr/local/cargo/bin/moq-pub
+CMD [ "publish" ]
+
+# moq-rs image with just the binaries
+FROM rust:latest as moq-rs
+
+LABEL org.opencontainers.image.source=https://github.com/kixelated/moq-rs
+LABEL org.opencontainers.image.licenses="MIT OR Apache-2.0"
+
+# Fly.io entrypoint
+ADD deploy/fly-relay.sh .
+
+# Copy the compiled binaries
+COPY --from=builder /usr/local/cargo/bin /usr/local/cargo/bin

HACKATHON.md

@@ -0,0 +1,53 @@
+# Hackathon
+
+IETF Prague 118
+
+## MoqTransport
+
+Reference libraries are available at [moq-rs](https://github.com/kixelated/moq-rs) and [moq-js](https://github.com/kixelated/moq-js). The Rust library is [well documented](https://docs.rs/moq-transport/latest/moq_transport/) but the web library, not so much.
+
+**TODO** Update both to draft-01.
+**TODO** Switch any remaining forks over to extensions. ex: track_id in SUBSCRIBE
+
+The stream mapping right now is quite rigid: `stream == group == object`.
+
+**TODO** Support multiple objects per group. They MUST NOT use different priorities, different tracks, or out-of-order sequences.
+
+The API and cache aren't designed to send/receive arbitrary objects over arbitrary streams as specified in the draft. I don't think it should, and it wouldn't be possible to implement in time for the hackathon anyway.
+
+**TODO** Make an extension to enforce this stream mapping?
+
+## Generic Relay
+
+I'm hosting a simple CDN at: `relay.quic.video`
+
+The traffic is sharded based on the WebTransport path to avoid namespace collisions. Think of it like a customer ID, although it's completely unauthenticated for now. Use your username or whatever string you want: `CONNECT https://relay.quic.video/alan`.
+
+**TODO** Currently, it performs an implicit `ANNOUNCE ""` when `role=publisher`. This means there can only be a single publisher per shard and `role=both` is not supported. I should have explicit `ANNOUNCE` messages supported before the hackathon to remove this limitation.
+
+**TODO** I don't know if I will have subscribe hints fully working in time. They will be parsed but might be ignored.
+
+## CMAF Media
+
+You can [publish](https://quic.video/publish) and [watch](https://quic.video/watch) broadcasts.
+There's a [24/7 bunny stream](https://quic.video/watch/bbb) or you can publish your own using [moq-pub](https://github.com/kixelated/moq-rs/tree/main/moq-pub).
+
+If you want to fetch from the relay directly, the name of the broadcast is the path. For example, `https://quic.video/watch/bbb` can be accessed at `relay.quic.video/bbb`. 
+
+The namespace is empty and the catalog track is `.catalog`. I'm currently using simple JSON catalog with no support for delta updates.
+
+**TODO** update to the proposed [Warp catalog](https://datatracker.ietf.org/doc/draft-wilaw-moq-catalogformat/).
+
+The media tracks uses a single (unbounded) object per group. Video groups are per GoP, while audio groups are per frame. There's also an init track containing information required to initialize the decoder.
+
+**TODO** Base64 encode the init track in the catalog.
+
+
+## Clock
+
+**TODO** Host a clock demo that sends a group per second:
+
+```
+GROUP: YYYY-MM-DD HH:MM
+OBJECT: SS
+```

README.md

@@ -1,40 +1,64 @@
-# Media over QUIC
+<p align="center">
+	<img height="128px" src="https://github.com/kixelated/moq-rs/blob/main/.github/logo.svg" alt="Media over QUIC">
+</p>
 
 Media over QUIC (MoQ) is a live media delivery protocol utilizing QUIC streams.
-See the [Warp draft](https://datatracker.ietf.org/doc/draft-lcurley-warp/).
+See [quic.video](https://quic.video) for more information.
 
-This repository is a Rust server that supports both contribution (ingest) and distribution (playback).
+This repository contains a few crates:
-It requires a client, such as [moq-js](https://github.com/kixelated/moq-js).
 
-## Setup
+-   **moq-relay**: A relay server, accepting content from publishers and fanning it out to subscribers.
+-   **moq-pub**: A publish client, accepting media from stdin (ex. via ffmpeg) and sending it to a remote server.
+-   **moq-transport**: An async implementation of the underlying MoQ protocol.
+-   **moq-api**: A HTTP API server that stores the origin for each broadcast, backed by redis.
 
-### Certificates
+There's currently no way to view media with this repo; you'll need to use [moq-js](https://github.com/kixelated/moq-js) for that.
 
-Unfortunately, QUIC mandates TLS and makes local development difficult.
+## Development
-If you have a valid certificate you can use it instead of self-signing.
 
-Use [mkcert](https://github.com/FiloSottile/mkcert) to generate a self-signed certificate.
+Use the [dev helper scripts](dev/README.md) for local development.
-Unfortunately, this currently requires Go in order to [fork](https://github.com/FiloSottile/mkcert/pull/513) the tool.
-
-```
-./cert/generate
-```
-
-Unfortunately, WebTransport in Chrome currently (May 2023) doesn't verify certificates using the root CA.
-The workaround is to use the `serverFingerprints` options, which requires the certificate MUST be only valid for at most **14 days**.
-This is also why we're using a fork of mkcert, because it generates certificates valid for years by default.
-This limitation will be removed once Chrome uses the system CA for WebTransport.
 
 ## Usage
 
-Run the server:
+### moq-relay
 
-```
+**moq-relay** is a server that forwards subscriptions from publishers to subscribers, caching and deduplicating along the way.
-cargo run
+It's designed to be run in a datacenter, relaying media across multiple hops to deduplicate and improve QoS.
-```
+The relays register themselves via the [moq-api](moq-api) endpoints, which is used to discover other relays and share broadcasts.
 
-This listens for WebTransport connections on `https://localhost:4443` by default.
+Notable arguments:
-Use a [MoQ client](https://github.com/kixelated/moq-js) to connect to the server.
+
+-   `--listen <ADDR>` Listen on this address, default: `[::]:4443`
+-   `--tls-cert <CERT>` Use the certificate file at this path
+-   `--tls-key <KEY>` Use the private key at this path
+-   `--dev` Listen via HTTPS as well, serving the `/fingerprint` of the self-signed certificate. (dev only)
+
+This listens for WebTransport connections on `UDP https://localhost:4443` by default.
+You need a client to connect to that address, to both publish and consume media.
+
+### moq-pub
+
+This is a client that publishes a fMP4 stream from stdin over MoQ.
+This can be combined with ffmpeg (and other tools) to produce a live stream.
+
+Notable arguments:
+
+-   `<URL>` connect to the given address, which must start with `https://` for WebTransport.
+
+**NOTE**: We're very particular about the fMP4 ingested. See [this script](dev/pub) for the required ffmpeg flags.
+
+### moq-transport
+
+A media-agnostic library used by [moq-relay](moq-relay) and [moq-pub](moq-pub) to serve the underlying subscriptions.
+It has caching/deduplication built-in, so your application is oblivious to the number of connections under the hood.
+
+See the published [crate](https://crates.io/crates/moq-transport) and [documentation](https://docs.rs/moq-transport/latest/moq_transport/).
+
+### moq-api
+
+This is a API server that exposes a REST API.
+It's used by relays to inserts themselves as origins when publishing, and to find the origin when subscribing.
+It's basically just a thin wrapper around redis that is only needed to run multiple relays in a (simple) cluster.
 
 ## License
 

deploy/fly-relay.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env sh
+
+mkdir cert
+# Nothing to see here...
+echo "$MOQ_CRT" | base64 -d > dev/moq-demo.crt
+echo "$MOQ_KEY" | base64 -d > dev/moq-demo.key
+
+RUST_LOG=info /usr/local/cargo/bin/moq-relay --tls-cert dev/moq-demo.crt --tls-key dev/moq-demo.key

deploy/fly.toml

@@ -0,0 +1,20 @@
+app = "englishm-moq-relay"
+kill_signal = "SIGINT"
+kill_timeout = 5
+
+[env]
+PORT = "4443"
+
+[experimental]
+cmd = "./fly-relay.sh"
+
+[[services]]
+internal_port = 4443
+protocol = "udp"
+
+[services.concurrency]
+hard_limit = 25
+soft_limit = 20
+
+[[services.ports]]
+port = "4443"

deploy/publish.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+set -euo pipefail
+
+ADDR=${ADDR:-"https://relay.quic.video"}
+NAME=${NAME:-"bbb"}
+URL=${URL:-"http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4"}
+
+# Download the funny bunny
+wget -nv "${URL}" -O "${NAME}.mp4"
+
+# ffmpeg
+#   -hide_banner: Hide the banner
+#   -v quiet: and any other output
+#   -stats: But we still want some stats on stderr
+#   -stream_loop -1: Loop the broadcast an infinite number of times
+#   -re: Output in real-time
+#   -i "${INPUT}": Read from a file on disk
+#   -vf "drawtext": Render the current time in the corner of the video
+#   -an: Disable audio for now
+#   -b:v 3M: Output video at 3Mbps
+#   -preset ultrafast: Don't use much CPU at the cost of quality
+#   -tune zerolatency: Optimize for latency at the cost of quality
+#   -f mp4: Output to mp4 format
+#   -movflags: Build a fMP4 file with a frame per fragment
+# - | moq-pub: Output to stdout and moq-pub to publish
+
+# Run ffmpeg
+ffmpeg \
+	-stream_loop -1 \
+	-hide_banner \
+	-v quiet \
+	-re \
+    -i "${NAME}.mp4" \
+	-vf "drawtext=fontfile=/usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf:text='%{gmtime\: %H\\\\\:%M\\\\\:%S.%3N}':x=(W-tw)-24:y=24:fontsize=48:fontcolor=white:box=1:boxcolor=black@0.5" \
+	-an \
+	-b:v 3M \
+	-preset ultrafast \
+	-tune zerolatency \
+    -f mp4 \
+	-movflags empty_moov+frag_every_frame+separate_moof+omit_tfhd_offset \
+	- | moq-pub "${ADDR}/${NAME}"

dev/.gitignore

@@ -1,3 +1,4 @@
 *.crt
 *.key
 *.hex
+*.mp4

dev/README.md

@@ -0,0 +1,118 @@
+# Local Development
+
+This is a collection of helpful scripts for local development.
+
+## Setup
+
+### moq-relay
+
+Unfortunately, QUIC mandates TLS and makes local development difficult.
+If you have a valid certificate you can use it instead of self-signing.
+
+Use [mkcert](https://github.com/FiloSottile/mkcert) to generate a self-signed certificate.
+Unfortunately, this currently requires [Go](https://golang.org/) to be installed in order to [fork](https://github.com/FiloSottile/mkcert/pull/513) the tool.
+Somebody should get that merged or make something similar in Rust...
+
+```bash
+./dev/cert
+```
+
+Unfortunately, WebTransport in Chrome currently (May 2023) doesn't verify certificates using the root CA.
+The workaround is to use the `serverFingerprints` options, which requires the certificate MUST be only valid for at most **14 days**.
+This is also why we're using a fork of mkcert, because it generates certificates valid for years by default.
+This limitation will be removed once Chrome uses the system CA for WebTransport.
+
+### moq-pub
+
+You'll want some test footage to broadcast.
+Anything works, but make sure the codec is supported by the player since `moq-pub` does not re-encode.
+
+Here's a criticially acclaimed short film:
+
+```bash
+mkdir media
+wget http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4 -O dev/source.mp4
+```
+
+`moq-pub` uses [ffmpeg](https://ffmpeg.org/) to convert the media to fMP4.
+You should have it installed already if you're a video nerd, otherwise:
+
+```bash
+brew install ffmpeg
+```
+
+### moq-api
+
+`moq-api` uses a redis instance to store active origins for clustering.
+This is not relevant for most local development and the code path is skipped by default.
+
+However, if you want to test the clustering, you'll need either either [Docker](https://www.docker.com/) or [Podman](https://podman.io/) installed.
+We run the redis instance via a container automatically as part of `dev/api`.
+
+## Development
+
+**tl;dr** run these commands in seperate terminals:
+
+```bash
+./dev/cert
+./dev/relay
+./dev/pub
+```
+
+They will each print out a URL you can use to publish/watch broadcasts.
+
+### moq-relay
+
+You can run the relay with the following command, automatically using the self-signed certificates generated earlier.
+This listens for WebTransport connections on WebTransport `https://localhost:4443` by default.
+
+```bash
+./dev/relay
+```
+
+It will print out a URL when you can use to publish. Alternatively, you can use `dev/pub` instead.
+
+> Publish URL: https://quic.video/publish/?server=localhost:4443
+
+### moq-pub
+
+The following command runs a development instance, broadcasing `dev/source.mp4` to WebTransport `https://localhost:4443`:
+
+```bash
+./dev/pub
+```
+
+It will print out a URL when you can use to watch.
+By default, the broadcast name is `dev` but you can overwrite it with the `NAME` env.
+
+> Watch URL: https://quic.video/watch/dev?server=localhost:4443
+
+If you're debugging encoding issues, you can use this script to dump the file to disk instead, defaulting to
+`dev/output.mp4`.
+
+```bash
+./dev/pub-file
+```
+
+### moq-api
+
+The following commands runs an API server, listening for HTTP requests on `http://localhost:4442` by default.
+
+```bash
+./dev/api
+```
+
+Nodes can now register themselves via the API, which means you can run multiple interconnected relays.
+There's two separate `dev/relay-0` and `dev/relay-1` scripts to test clustering locally:
+
+```bash
+./dev/relay-0
+./dev/relay-1
+```
+
+These listen on `:4443` and `:4444` respectively, inserting themselves into the origin database as `localhost:$PORT`.
+
+There's also a separate `dev/pub-1` script to publish to the `:4444` instance.
+You can use the exisitng `dev/pub` script to publish to the `:4443` instance.
+
+If all goes well, you would be able to publish to one relay and watch from the other.

dev/api

@@ -0,0 +1,45 @@
+#!/bin/bash
+set -euo pipefail
+
+# Change directory to the root of the project
+cd "$(dirname "$0")/.."
+
+# Use debug logging by default
+export RUST_LOG="${RUST_LOG:-debug}"
+
+# Run the API server on port 4442 by default
+HOST="${HOST:-[::]}"
+PORT="${PORT:-4442}"
+LISTEN="${LISTEN:-$HOST:$PORT}"
+
+# Check for Podman/Docker and set runtime accordingly
+if command -v podman &> /dev/null; then
+    RUNTIME=podman
+elif command -v docker &> /dev/null; then
+    RUNTIME=docker
+else
+    echo "Neither podman or docker found in PATH. Exiting."
+    exit 1
+fi
+
+REDIS_PORT=${REDIS_PORT:-6400} # The default is 6379, but we'll use 6400 to avoid conflicts
+
+# Cleanup function to stop Redis when script exits
+cleanup() {
+    $RUNTIME rm -f moq-redis || true
+}
+
+# Stop the redis instance if it's still running
+cleanup
+
+# Run a Redis instance
+REDIS_CONTAINER=$($RUNTIME run --rm --name moq-redis -d -p "$REDIS_PORT:6379" redis:latest)
+
+# Cleanup function to stop Redis when script exits
+trap cleanup EXIT
+
+# Default to a sqlite database in memory
+DATABASE="${DATABASE-sqlite::memory:}"
+
+# Run the relay and forward any arguments
+cargo run --bin moq-api -- --listen "$LISTEN" --redis "redis://localhost:$REDIS_PORT" "$@"

dev/pub

@@ -0,0 +1,40 @@
+#!/bin/bash
+set -euo pipefail
+
+# Change directory to the root of the project
+cd "$(dirname "$0")/.."
+
+# Use debug logging by default
+export RUST_LOG="${RUST_LOG:-debug}"
+
+# Connect to localhost by default.
+HOST="${HOST:-localhost}"
+PORT="${PORT:-4443}"
+ADDR="${ADDR:-$HOST:$PORT}"
+
+# Generate a random 16 character name by default.
+#NAME="${NAME:-$(head /dev/urandom | LC_ALL=C tr -dc 'a-zA-Z0-9' | head -c 16)}"
+
+# JK use the name "dev" instead
+# TODO use that random name if the host is not localhost
+NAME="${NAME:-dev}"
+
+# Combine the host and name into a URL.
+URL="${URL:-"https://$ADDR/$NAME"}"
+
+# Default to a source video
+INPUT="${INPUT:-dev/source.mp4}"
+
+# Print out the watch URL
+echo "Watch URL: https://quic.video/watch/$NAME?server=$ADDR"
+
+# Run ffmpeg and pipe the output to moq-pub
+# TODO enable audio again once fixed.
+ffmpeg -hide_banner -v quiet \
+	-stream_loop -1 -re \
+	-i "$INPUT" \
+	-c copy \
+	-an \
+	-f mp4 -movflags cmaf+separate_moof+delay_moov+skip_trailer \
+	-frag_duration 1 \
+	- | cargo run --bin moq-pub -- "$URL" "$@"

dev/pub-1

@@ -0,0 +1,10 @@
+#!/bin/bash
+set -euo pipefail
+
+# Change directory to the root of the project
+cd "$(dirname "$0")/.."
+
+# Connect to the 2nd relay by default.
+export PORT="${PORT:-4444}"
+
+./dev/pub

dev/pub-file

@@ -0,0 +1,90 @@
+#!/bin/bash
+set -euo pipefail
+
+# Change directory to the root of the project
+cd "$(dirname "$0")/.."
+
+# Default to a source video
+INPUT="${INPUT:-dev/source.mp4}"
+
+# Output the fragmented MP4 to disk for testing.
+OUTPUT="${OUTPUT:-dev/output.mp4}"
+
+# Run ffmpeg the same as dev/pub, but:
+#   - print any errors/warnings
+#   - only loop twice
+#
+# Note this is artificially slowed down to real-time using the -re flag; you can remove it.
+ffmpeg \
+	-re \
+	-y \
+	-i "$INPUT" \
+	-c copy \
+	-fps_mode passthrough \
+	-f mp4 -movflags cmaf+separate_moof+delay_moov+skip_trailer \
+	-frag_duration 1 \
+	"${OUTPUT}"
+
+# % ffmpeg -f mp4 --ffmpeg -h muxer=mov
+#
+# ffmpeg version 6.0 Copyright (c) 2000-2023 the FFmpeg developers
+# Muxer mov [QuickTime / MOV]:
+#     Common extensions: mov.
+#     Default video codec: h264.
+#     Default audio codec: aac.
+# mov/mp4/tgp/psp/tg2/ipod/ismv/f4v muxer AVOptions:
+#   -movflags          <flags>      E.......... MOV muxer flags (default 0)
+#      rtphint                      E.......... Add RTP hint tracks
+#      empty_moov                   E.......... Make the initial moov atom empty
+#      frag_keyframe                E.......... Fragment at video keyframes
+#      frag_every_frame              E.......... Fragment at every frame
+#      separate_moof                E.......... Write separate moof/mdat atoms for each track
+#      frag_custom                  E.......... Flush fragments on caller requests
+#      isml                         E.......... Create a live smooth streaming feed (for pushing to a publishing point)
+#      faststart                    E.......... Run a second pass to put the index (moov atom) at the beginning of the file
+#      omit_tfhd_offset              E.......... Omit the base data offset in tfhd atoms
+#      disable_chpl                 E.......... Disable Nero chapter atom
+#      default_base_moof              E.......... Set the default-base-is-moof flag in tfhd atoms
+#      dash                         E.......... Write DASH compatible fragmented MP4
+#      cmaf                         E.......... Write CMAF compatible fragmented MP4
+#      frag_discont                 E.......... Signal that the next fragment is discontinuous from earlier ones
+#      delay_moov                   E.......... Delay writing the initial moov until the first fragment is cut, or until the first fragment flush
+#      global_sidx                  E.......... Write a global sidx index at the start of the file
+#      skip_sidx                    E.......... Skip writing of sidx atom
+#      write_colr                   E.......... Write colr atom even if the color info is unspecified (Experimental, may be renamed or changed, do not use from scripts)
+#      prefer_icc                   E.......... If writing colr atom prioritise usage of ICC profile if it exists in stream packet side data
+#      write_gama                   E.......... Write deprecated gama atom
+#      use_metadata_tags              E.......... Use mdta atom for metadata.
+#      skip_trailer                 E.......... Skip writing the mfra/tfra/mfro trailer for fragmented files
+#      negative_cts_offsets              E.......... Use negative CTS offsets (reducing the need for edit lists)
+#   -moov_size         <int>        E.......... maximum moov size so it can be placed at the begin (from 0 to INT_MAX) (default 0)
+#   -rtpflags          <flags>      E.......... RTP muxer flags (default 0)
+#      latm                         E.......... Use MP4A-LATM packetization instead of MPEG4-GENERIC for AAC
+#      rfc2190                      E.......... Use RFC 2190 packetization instead of RFC 4629 for H.263
+#      skip_rtcp                    E.......... Don't send RTCP sender reports
+#      h264_mode0                   E.......... Use mode 0 for H.264 in RTP
+#      send_bye                     E.......... Send RTCP BYE packets when finishing
+#   -skip_iods         <boolean>    E.......... Skip writing iods atom. (default true)
+#   -iods_audio_profile <int>        E.......... iods audio profile atom. (from -1 to 255) (default -1)
+#   -iods_video_profile <int>        E.......... iods video profile atom. (from -1 to 255) (default -1)
+#   -frag_duration     <int>        E.......... Maximum fragment duration (from 0 to INT_MAX) (default 0)
+#   -min_frag_duration <int>        E.......... Minimum fragment duration (from 0 to INT_MAX) (default 0)
+#   -frag_size         <int>        E.......... Maximum fragment size (from 0 to INT_MAX) (default 0)
+#   -ism_lookahead     <int>        E.......... Number of lookahead entries for ISM files (from 0 to 255) (default 0)
+#   -video_track_timescale <int>        E.......... set timescale of all video tracks (from 0 to INT_MAX) (default 0)
+#   -brand             <string>     E.......... Override major brand
+#   -use_editlist      <boolean>    E.......... use edit list (default auto)
+#   -fragment_index    <int>        E.......... Fragment number of the next fragment (from 1 to INT_MAX) (default 1)
+#   -mov_gamma         <float>      E.......... gamma value for gama atom (from 0 to 10) (default 0)
+#   -frag_interleave   <int>        E.......... Interleave samples within fragments (max number of consecutive samples, lower is tighter interleaving, but with more overhead) (from 0 to INT_MAX) (default 0)
+#   -encryption_scheme <string>     E.......... Configures the encryption scheme, allowed values are none, cenc-aes-ctr
+#   -encryption_key    <binary>     E.......... The media encryption key (hex)
+#   -encryption_kid    <binary>     E.......... The media encryption key identifier (hex)
+#   -use_stream_ids_as_track_ids <boolean>    E.......... use stream ids as track ids (default false)
+#   -write_btrt        <boolean>    E.......... force or disable writing btrt (default auto)
+#   -write_tmcd        <boolean>    E.......... force or disable writing tmcd (default auto)
+#   -write_prft        <int>        E.......... Write producer reference time box with specified time source (from 0 to 2) (default 0)
+#      wallclock       1            E..........
+#      pts             2            E..........
+#   -empty_hdlr_name   <boolean>    E.......... write zero-length name string in hdlr atoms within mdia and minf atoms (default false)
+#   -movie_timescale   <int>        E.......... set movie timescale (from 1 to INT_MAX) (default 1000)

dev/relay

@@ -0,0 +1,37 @@
+#!/bin/bash
+set -euo pipefail
+
+# Change directory to the root of the project
+cd "$(dirname "$0")/.."
+
+# Use debug logging by default
+export RUST_LOG="${RUST_LOG:-debug}"
+
+# Default to a self-signed certificate
+# TODO automatically generate if it doesn't exist.
+CERT="${CERT:-dev/localhost.crt}"
+KEY="${KEY:-dev/localhost.key}"
+
+# Default to listening on localhost:4443
+HOST="${HOST:-[::]}"
+PORT="${PORT:-4443}"
+LISTEN="${LISTEN:-$HOST:$PORT}"
+
+# A list of optional args
+ARGS=""
+
+# Connect to the given URL to get origins.
+# TODO default to a public instance?
+if [ -n "${API-}" ]; then
+	ARGS="$ARGS --api $API"
+fi
+
+# Provide our node URL when registering origins.
+if [ -n "${NODE-}" ]; then
+	ARGS="$ARGS --api-node $NODE"
+fi
+
+echo "Publish URL: https://quic.video/publish/?server=localhost:${PORT}"
+
+# Run the relay and forward any arguments
+cargo run --bin moq-relay -- --listen "$LISTEN" --tls-cert "$CERT" --tls-key "$KEY" --dev $ARGS -- "$@"

dev/relay-0

@@ -0,0 +1,12 @@
+#!/bin/bash
+set -euo pipefail
+
+# Change directory to the root of the project
+cd "$(dirname "$0")/.."
+
+# Run an instance that advertises itself to the origin API.
+export PORT="${PORT:-4443}"
+export API="${API:-http://localhost:4442}" # TODO support HTTPS
+export NODE="${NODE:-https://localhost:$PORT}"
+
+./dev/relay

dev/relay-1

@@ -0,0 +1,12 @@
+#!/bin/bash
+set -euo pipefail
+
+# Change directory to the root of the project
+cd "$(dirname "$0")/.."
+
+# Run an instance that advertises itself to the origin API.
+export PORT="${PORT:-4444}"
+export API="${API:-http://localhost:4442}" # TODO support HTTPS
+export NODE="${NODE:-https://localhost:$PORT}"
+
+./dev/relay

dev/setup

@@ -0,0 +1,2 @@
+#!/bin/bash
+set -euo pipefail

moq-api/Cargo.toml

@@ -0,0 +1,43 @@
+[package]
+name = "moq-api"
+description = "Media over QUIC"
+authors = ["Luke Curley"]
+repository = "https://github.com/kixelated/moq-rs"
+license = "MIT OR Apache-2.0"
+
+version = "0.0.1"
+edition = "2021"
+
+keywords = ["quic", "http3", "webtransport", "media", "live"]
+categories = ["multimedia", "network-programming", "web-programming"]
+
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+# HTTP server
+axum = "0.6"
+hyper = { version = "0.14", features = ["full"] }
+tokio = { version = "1", features = ["full"] }
+
+# HTTP client
+reqwest = { version = "0.11", features = ["json", "rustls-tls"] }
+
+# JSON encoding
+serde = "1"
+serde_json = "1"
+
+# CLI
+clap = { version = "4", features = ["derive"] }
+
+# Database
+redis = { version = "0.23", features = [
+	"tokio-rustls-comp",
+	"connection-manager",
+] }
+url = { version = "2", features = ["serde"] }
+
+# Error handling
+log = "0.4"
+env_logger = "0.9"
+thiserror = "1"

moq-api/README.md

@@ -0,0 +1,4 @@
+# moq-api
+
+A thin HTTP API that wraps Redis.
+Basically I didn't want the relays connecting to Redis directly.

moq-api/src/client.rs

@@ -0,0 +1,56 @@
+use url::Url;
+
+use crate::{ApiError, Origin};
+
+#[derive(Clone)]
+pub struct Client {
+	// The address of the moq-api server
+	url: Url,
+
+	client: reqwest::Client,
+}
+
+impl Client {
+	pub fn new(url: Url) -> Self {
+		let client = reqwest::Client::new();
+		Self { url, client }
+	}
+
+	pub async fn get_origin(&self, id: &str) -> Result<Option<Origin>, ApiError> {
+		let url = self.url.join("origin/")?.join(id)?;
+		let resp = self.client.get(url).send().await?;
+		if resp.status() == reqwest::StatusCode::NOT_FOUND {
+			return Ok(None);
+		}
+
+		let origin: Origin = resp.json().await?;
+		Ok(Some(origin))
+	}
+
+	pub async fn set_origin(&mut self, id: &str, origin: &Origin) -> Result<(), ApiError> {
+		let url = self.url.join("origin/")?.join(id)?;
+
+		let resp = self.client.post(url).json(origin).send().await?;
+		resp.error_for_status()?;
+
+		Ok(())
+	}
+
+	pub async fn delete_origin(&mut self, id: &str) -> Result<(), ApiError> {
+		let url = self.url.join("origin/")?.join(id)?;
+
+		let resp = self.client.delete(url).send().await?;
+		resp.error_for_status()?;
+
+		Ok(())
+	}
+
+	pub async fn patch_origin(&mut self, id: &str, origin: &Origin) -> Result<(), ApiError> {
+		let url = self.url.join("origin/")?.join(id)?;
+
+		let resp = self.client.patch(url).json(origin).send().await?;
+		resp.error_for_status()?;
+
+		Ok(())
+	}
+}

moq-api/src/error.rs

@@ -0,0 +1,16 @@
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum ApiError {
+	#[error("redis error: {0}")]
+	Redis(#[from] redis::RedisError),
+
+	#[error("reqwest error: {0}")]
+	Request(#[from] reqwest::Error),
+
+	#[error("hyper error: {0}")]
+	Hyper(#[from] hyper::Error),
+
+	#[error("url error: {0}")]
+	Url(#[from] url::ParseError),
+}

moq-api/src/lib.rs

@@ -0,0 +1,7 @@
+mod client;
+mod error;
+mod model;
+
+pub use client::*;
+pub use error::*;
+pub use model::*;

moq-api/src/main.rs

@@ -0,0 +1,14 @@
+use clap::Parser;
+
+mod server;
+use moq_api::ApiError;
+use server::{Server, ServerConfig};
+
+#[tokio::main]
+async fn main() -> Result<(), ApiError> {
+	env_logger::init();
+
+	let config = ServerConfig::parse();
+	let server = Server::new(config);
+	server.run().await
+}

moq-api/src/model.rs

@@ -0,0 +1,8 @@
+use serde::{Deserialize, Serialize};
+
+use url::Url;
+
+#[derive(Serialize, Deserialize, PartialEq, Eq)]
+pub struct Origin {
+	pub url: Url,
+}

moq-api/src/server.rs

@@ -0,0 +1,171 @@
+use std::net;
+
+use axum::{
+	extract::{Path, State},
+	http::StatusCode,
+	response::{IntoResponse, Response},
+	routing::get,
+	Json, Router,
+};
+
+use clap::Parser;
+
+use redis::{aio::ConnectionManager, AsyncCommands};
+
+use moq_api::{ApiError, Origin};
+
+/// Runs a HTTP API to create/get origins for broadcasts.
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about = None)]
+pub struct ServerConfig {
+	/// Listen for HTTP requests on the given address
+	#[arg(long)]
+	pub listen: net::SocketAddr,
+
+	/// Connect to the given redis instance
+	#[arg(long)]
+	pub redis: url::Url,
+}
+
+pub struct Server {
+	config: ServerConfig,
+}
+
+impl Server {
+	pub fn new(config: ServerConfig) -> Self {
+		Self { config }
+	}
+
+	pub async fn run(self) -> Result<(), ApiError> {
+		log::info!("connecting to redis: url={}", self.config.redis);
+
+		// Create the redis client.
+		let redis = redis::Client::open(self.config.redis)?;
+		let redis = redis
+			.get_tokio_connection_manager() // TODO get_tokio_connection_manager_with_backoff?
+			.await?;
+
+		let app = Router::new()
+			.route(
+				"/origin/:id",
+				get(get_origin)
+					.post(set_origin)
+					.delete(delete_origin)
+					.patch(patch_origin),
+			)
+			.with_state(redis);
+
+		log::info!("serving requests: bind={}", self.config.listen);
+
+		axum::Server::bind(&self.config.listen)
+			.serve(app.into_make_service())
+			.await?;
+
+		Ok(())
+	}
+}
+
+async fn get_origin(
+	Path(id): Path<String>,
+	State(mut redis): State<ConnectionManager>,
+) -> Result<Json<Origin>, AppError> {
+	let key = origin_key(&id);
+
+	let payload: Option<String> = redis.get(&key).await?;
+	let payload = payload.ok_or(AppError::NotFound)?;
+	let origin: Origin = serde_json::from_str(&payload)?;
+
+	Ok(Json(origin))
+}
+
+async fn set_origin(
+	State(mut redis): State<ConnectionManager>,
+	Path(id): Path<String>,
+	Json(origin): Json<Origin>,
+) -> Result<(), AppError> {
+	// TODO validate origin
+
+	let key = origin_key(&id);
+
+	// Convert the input back to JSON after validating it add adding any fields (TODO)
+	let payload = serde_json::to_string(&origin)?;
+
+	let res: Option<String> = redis::cmd("SET")
+		.arg(key)
+		.arg(payload)
+		.arg("NX")
+		.arg("EX")
+		.arg(600) // Set the key to expire in 10 minutes; the origin needs to keep refreshing it.
+		.query_async(&mut redis)
+		.await?;
+
+	if res.is_none() {
+		return Err(AppError::Duplicate);
+	}
+
+	Ok(())
+}
+
+async fn delete_origin(Path(id): Path<String>, State(mut redis): State<ConnectionManager>) -> Result<(), AppError> {
+	let key = origin_key(&id);
+	match redis.del(key).await? {
+		0 => Err(AppError::NotFound),
+		_ => Ok(()),
+	}
+}
+
+// Update the expiration deadline.
+async fn patch_origin(
+	Path(id): Path<String>,
+	State(mut redis): State<ConnectionManager>,
+	Json(origin): Json<Origin>,
+) -> Result<(), AppError> {
+	let key = origin_key(&id);
+
+	// Make sure the contents haven't changed
+	// TODO make a LUA script to do this all in one operation.
+	let payload: Option<String> = redis.get(&key).await?;
+	let payload = payload.ok_or(AppError::NotFound)?;
+	let expected: Origin = serde_json::from_str(&payload)?;
+
+	if expected != origin {
+		return Err(AppError::Duplicate);
+	}
+
+	// Reset the timeout to 10 minutes.
+	match redis.expire(key, 600).await? {
+		0 => Err(AppError::NotFound),
+		_ => Ok(()),
+	}
+}
+
+fn origin_key(id: &str) -> String {
+	format!("origin.{}", id)
+}
+
+#[derive(thiserror::Error, Debug)]
+enum AppError {
+	#[error("redis error")]
+	Redis(#[from] redis::RedisError),
+
+	#[error("json error")]
+	Json(#[from] serde_json::Error),
+
+	#[error("not found")]
+	NotFound,
+
+	#[error("duplicate ID")]
+	Duplicate,
+}
+
+// Tell axum how to convert `AppError` into a response.
+impl IntoResponse for AppError {
+	fn into_response(self) -> Response {
+		match self {
+			AppError::Redis(e) => (StatusCode::INTERNAL_SERVER_ERROR, format!("redis error: {}", e)).into_response(),
+			AppError::Json(e) => (StatusCode::INTERNAL_SERVER_ERROR, format!("json error: {}", e)).into_response(),
+			AppError::NotFound => StatusCode::NOT_FOUND.into_response(),
+			AppError::Duplicate => StatusCode::CONFLICT.into_response(),
+		}
+	}
+}

moq-pub/Cargo.toml

@@ -0,0 +1,47 @@
+[package]
+name = "moq-pub"
+description = "Media over QUIC"
+authors = ["Mike English", "Luke Curley"]
+repository = "https://github.com/kixelated/moq-rs"
+license = "MIT OR Apache-2.0"
+
+version = "0.1.0"
+edition = "2021"
+
+keywords = ["quic", "http3", "webtransport", "media", "live"]
+categories = ["multimedia", "network-programming", "web-programming"]
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+moq-transport = { path = "../moq-transport" }
+
+# QUIC
+quinn = "0.10"
+webtransport-quinn = "0.6"
+#webtransport-quinn = { path = "../../webtransport-rs/webtransport-quinn" }
+url = "2"
+
+# Crypto
+rustls = { version = "0.21", features = ["dangerous_configuration"] }
+rustls-native-certs = "0.6"
+rustls-pemfile = "1"
+
+# Async stuff
+tokio = { version = "1", features = ["full"] }
+
+# CLI, logging, error handling
+clap = { version = "4", features = ["derive"] }
+log = { version = "0.4", features = ["std"] }
+env_logger = "0.9"
+mp4 = "0.13"
+anyhow = { version = "1", features = ["backtrace"] }
+serde_json = "1"
+rfc6381-codec = "0.1"
+tracing = "0.1"
+tracing-subscriber = "0.3"
+
+[build-dependencies]
+clap = { version = "4", features = ["derive"] }
+clap_mangen = "0.2"
+url = "2"

moq-pub/README.md

@@ -0,0 +1,28 @@
+# moq-pub
+
+A command line tool for publishing media via Media over QUIC (MoQ).
+
+Expects to receive fragmented MP4 via standard input and connect to a MOQT relay.
+
+```
+ffmpeg ... - | moq-pub https://localhost:4443
+```
+
+### Invoking `moq-pub`:
+
+Here's how I'm currently testing things, with a local copy of Big Buck Bunny named `bbb_source.mp4`:
+
+```
+$ ffmpeg -hide_banner -v quiet -stream_loop -1 -re -i bbb_source.mp4 -an -f mp4 -movflags empty_moov+frag_every_frame+separate_moof+omit_tfhd_offset - | RUST_LOG=moq_pub=info moq-pub https://localhost:4443
+```
+
+This relies on having `moq-relay` (the relay server) already running locally in another shell.
+
+Note also that we're dropping the audio track (`-an`) above until audio playback is stabilized on the `moq-js` side.
+
+### Known issues
+
+-   Expects only one H.264/AVC1-encoded video track (catalog generation doesn't support audio tracks yet)
+-   Doesn't yet gracefully handle EOF - workaround: never stop sending it media (`-stream_loop -1`)
+-   Probably still full of lots of bugs
+-   Various other TODOs you can find in the code

moq-pub/build.rs

@@ -0,0 +1,15 @@
+include!("src/cli.rs");
+
+use clap::CommandFactory;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+	let out_dir = std::path::PathBuf::from(
+		std::env::var_os("OUT_DIR").ok_or(std::io::Error::new(std::io::ErrorKind::NotFound, "OUT_DIR not found"))?,
+	);
+	let cmd = Config::command();
+	let man = clap_mangen::Man::new(cmd);
+	let mut buffer: Vec<u8> = Default::default();
+	man.render(&mut buffer)?;
+	std::fs::write(out_dir.join("moq-pub.1"), buffer)?;
+	Ok(())
+}

moq-pub/src/cli.rs

@@ -0,0 +1,48 @@
+use clap::Parser;
+use std::{net, path};
+use url::Url;
+
+#[derive(Parser, Clone, Debug)]
+pub struct Config {
+	/// Listen for UDP packets on the given address.
+	#[arg(long, default_value = "[::]:0")]
+	pub bind: net::SocketAddr,
+
+	/// Advertise this frame rate in the catalog (informational)
+	// TODO auto-detect this from the input when not provided
+	#[arg(long, default_value = "24")]
+	pub fps: u8,
+
+	/// Advertise this bit rate in the catalog (informational)
+	// TODO auto-detect this from the input when not provided
+	#[arg(long, default_value = "1500000")]
+	pub bitrate: u32,
+
+	/// Connect to the given URL starting with https://
+	#[arg(value_parser = moq_url)]
+	pub url: Url,
+
+	/// Use the TLS root CA at this path, encoded as PEM.
+	///
+	/// This value can be provided multiple times for multiple roots.
+	/// If this is empty, system roots will be used instead
+	#[arg(long)]
+	pub tls_root: Vec<path::PathBuf>,
+
+	/// Danger: Disable TLS certificate verification.
+	///
+	/// Fine for local development, but should be used in caution in production.
+	#[arg(long)]
+	pub tls_disable_verify: bool,
+}
+
+fn moq_url(s: &str) -> Result<Url, String> {
+	let url = Url::try_from(s).map_err(|e| e.to_string())?;
+
+	// Make sure the scheme is moq
+	if url.scheme() != "https" {
+		return Err("url scheme must be https:// for WebTransport".to_string());
+	}
+
+	Ok(url)
+}

moq-pub/src/main.rs

@@ -0,0 +1,107 @@
+use std::{fs, io, sync::Arc, time};
+
+use anyhow::Context;
+use clap::Parser;
+
+mod cli;
+use cli::*;
+
+mod media;
+use media::*;
+
+use moq_transport::cache::broadcast;
+
+// TODO: clap complete
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+	env_logger::init();
+
+	// Disable tracing so we don't get a bunch of Quinn spam.
+	let tracer = tracing_subscriber::FmtSubscriber::builder()
+		.with_max_level(tracing::Level::WARN)
+		.finish();
+	tracing::subscriber::set_global_default(tracer).unwrap();
+
+	let config = Config::parse();
+
+	let (publisher, subscriber) = broadcast::new("");
+	let mut media = Media::new(&config, publisher).await?;
+
+	// Create a list of acceptable root certificates.
+	let mut roots = rustls::RootCertStore::empty();
+
+	if config.tls_root.is_empty() {
+		// Add the platform's native root certificates.
+		for cert in rustls_native_certs::load_native_certs().context("could not load platform certs")? {
+			roots
+				.add(&rustls::Certificate(cert.0))
+				.context("failed to add root cert")?;
+		}
+	} else {
+		// Add the specified root certificates.
+		for root in &config.tls_root {
+			let root = fs::File::open(root).context("failed to open root cert file")?;
+			let mut root = io::BufReader::new(root);
+
+			let root = rustls_pemfile::certs(&mut root).context("failed to read root cert")?;
+			anyhow::ensure!(root.len() == 1, "expected a single root cert");
+			let root = rustls::Certificate(root[0].to_owned());
+
+			roots.add(&root).context("failed to add root cert")?;
+		}
+	}
+
+	let mut tls_config = rustls::ClientConfig::builder()
+		.with_safe_defaults()
+		.with_root_certificates(roots)
+		.with_no_client_auth();
+
+	// Allow disabling TLS verification altogether.
+	if config.tls_disable_verify {
+		let noop = NoCertificateVerification {};
+		tls_config.dangerous().set_certificate_verifier(Arc::new(noop));
+	}
+
+	tls_config.alpn_protocols = vec![webtransport_quinn::ALPN.to_vec()]; // this one is important
+
+	let arc_tls_config = std::sync::Arc::new(tls_config);
+	let quinn_client_config = quinn::ClientConfig::new(arc_tls_config);
+
+	let mut endpoint = quinn::Endpoint::client(config.bind)?;
+	endpoint.set_default_client_config(quinn_client_config);
+
+	log::info!("connecting to relay: url={}", config.url);
+
+	let session = webtransport_quinn::connect(&endpoint, &config.url)
+		.await
+		.context("failed to create WebTransport session")?;
+
+	let session = moq_transport::session::Client::publisher(session, subscriber)
+		.await
+		.context("failed to create MoQ Transport session")?;
+
+	// TODO run a task that returns a 404 for all unknown subscriptions.
+	tokio::select! {
+		res = session.run() => res.context("session error")?,
+		res = media.run() => res.context("media error")?,
+	}
+
+	Ok(())
+}
+
+pub struct NoCertificateVerification {}
+
+impl rustls::client::ServerCertVerifier for NoCertificateVerification {
+	fn verify_server_cert(
+		&self,
+		_end_entity: &rustls::Certificate,
+		_intermediates: &[rustls::Certificate],
+		_server_name: &rustls::ServerName,
+		_scts: &mut dyn Iterator<Item = &[u8]>,
+		_ocsp_response: &[u8],
+		_now: time::SystemTime,
+	) -> Result<rustls::client::ServerCertVerified, rustls::Error> {
+		Ok(rustls::client::ServerCertVerified::assertion())
+	}
+}

moq-pub/src/media.rs

@@ -0,0 +1,430 @@
+use crate::cli::Config;
+use anyhow::{self, Context};
+use moq_transport::cache::{broadcast, fragment, segment, track};
+use moq_transport::VarInt;
+use mp4::{self, ReadBox};
+use serde_json::json;
+use std::cmp::max;
+use std::collections::HashMap;
+use std::io::Cursor;
+use std::time;
+use tokio::io::AsyncReadExt;
+
+pub struct Media {
+	// We hold on to publisher so we don't close then while media is still being published.
+	_broadcast: broadcast::Publisher,
+	_catalog: track::Publisher,
+	_init: track::Publisher,
+
+	// Tracks based on their track ID.
+	tracks: HashMap<u32, Track>,
+}
+
+impl Media {
+	pub async fn new(_config: &Config, mut broadcast: broadcast::Publisher) -> anyhow::Result<Self> {
+		let mut stdin = tokio::io::stdin();
+		let ftyp = read_atom(&mut stdin).await?;
+		anyhow::ensure!(&ftyp[4..8] == b"ftyp", "expected ftyp atom");
+
+		let moov = read_atom(&mut stdin).await?;
+		anyhow::ensure!(&moov[4..8] == b"moov", "expected moov atom");
+
+		let mut init = ftyp;
+		init.extend(&moov);
+
+		// We're going to parse the moov box.
+		// We have to read the moov box header to correctly advance the cursor for the mp4 crate.
+		let mut moov_reader = Cursor::new(&moov);
+		let moov_header = mp4::BoxHeader::read(&mut moov_reader)?;
+
+		// Parse the moov box so we can detect the timescales for each track.
+		let moov = mp4::MoovBox::read_box(&mut moov_reader, moov_header.size)?;
+
+		// Create the catalog track with a single segment.
+		let mut init_track = broadcast.create_track("0.mp4")?;
+		let mut init_segment = init_track.create_segment(segment::Info {
+			sequence: VarInt::ZERO,
+			priority: 0,
+			expires: None,
+		})?;
+
+		// Create a single fragment, optionally setting the size
+		let mut init_fragment = init_segment.create_fragment(fragment::Info {
+			sequence: VarInt::ZERO,
+			size: None, // size is only needed when we have multiple fragments.
+		})?;
+
+		init_fragment.write_chunk(init.into())?;
+
+		let mut tracks = HashMap::new();
+
+		for trak in &moov.traks {
+			let id = trak.tkhd.track_id;
+			let name = format!("{}.m4s", id);
+
+			let timescale = track_timescale(&moov, id);
+
+			// Store the track publisher in a map so we can update it later.
+			let track = broadcast.create_track(&name)?;
+			let track = Track::new(track, timescale);
+			tracks.insert(id, track);
+		}
+
+		let mut catalog = broadcast.create_track(".catalog")?;
+
+		// Create the catalog track
+		Self::serve_catalog(&mut catalog, &init_track.name, &moov)?;
+
+		Ok(Media {
+			_broadcast: broadcast,
+			_catalog: catalog,
+			_init: init_track,
+			tracks,
+		})
+	}
+
+	pub async fn run(&mut self) -> anyhow::Result<()> {
+		let mut stdin = tokio::io::stdin();
+		// The current track name
+		let mut current = None;
+
+		loop {
+			let atom = read_atom(&mut stdin).await?;
+
+			let mut reader = Cursor::new(&atom);
+			let header = mp4::BoxHeader::read(&mut reader)?;
+
+			match header.name {
+				mp4::BoxType::MoofBox => {
+					let moof = mp4::MoofBox::read_box(&mut reader, header.size).context("failed to read MP4")?;
+
+					// Process the moof.
+					let fragment = Fragment::new(moof)?;
+
+					// Get the track for this moof.
+					let track = self.tracks.get_mut(&fragment.track).context("failed to find track")?;
+
+					// Save the track ID for the next iteration, which must be a mdat.
+					anyhow::ensure!(current.is_none(), "multiple moof atoms");
+					current.replace(fragment.track);
+
+					// Publish the moof header, creating a new segment if it's a keyframe.
+					track.header(atom, fragment).context("failed to publish moof")?;
+				}
+				mp4::BoxType::MdatBox => {
+					// Get the track ID from the previous moof.
+					let track = current.take().context("missing moof")?;
+					let track = self.tracks.get_mut(&track).context("failed to find track")?;
+
+					// Publish the mdat atom.
+					track.data(atom).context("failed to publish mdat")?;
+				}
+
+				_ => {
+					// Skip unknown atoms
+				}
+			}
+		}
+	}
+
+	fn serve_catalog(
+		track: &mut track::Publisher,
+		init_track_name: &str,
+		moov: &mp4::MoovBox,
+	) -> Result<(), anyhow::Error> {
+		let mut segment = track.create_segment(segment::Info {
+			sequence: VarInt::ZERO,
+			priority: 0,
+			expires: None,
+		})?;
+
+		let mut tracks = Vec::new();
+
+		for trak in &moov.traks {
+			let mut track = json!({
+				"container": "mp4",
+				"init_track": init_track_name,
+				"data_track": format!("{}.m4s", trak.tkhd.track_id),
+			});
+
+			let stsd = &trak.mdia.minf.stbl.stsd;
+			if let Some(avc1) = &stsd.avc1 {
+				// avc1[.PPCCLL]
+				//
+				// let profile = 0x64;
+				// let constraints = 0x00;
+				// let level = 0x1f;
+				let profile = avc1.avcc.avc_profile_indication;
+				let constraints = avc1.avcc.profile_compatibility; // Not 100% certain here, but it's 0x00 on my current test video
+				let level = avc1.avcc.avc_level_indication;
+
+				let width = avc1.width;
+				let height = avc1.height;
+
+				let codec = rfc6381_codec::Codec::avc1(profile, constraints, level);
+				let codec_str = codec.to_string();
+
+				track["kind"] = json!("video");
+				track["codec"] = json!(codec_str);
+				track["width"] = json!(width);
+				track["height"] = json!(height);
+			} else if let Some(_hev1) = &stsd.hev1 {
+				// TODO https://github.com/gpac/mp4box.js/blob/325741b592d910297bf609bc7c400fc76101077b/src/box-codecs.js#L106
+				anyhow::bail!("HEVC not yet supported")
+			} else if let Some(mp4a) = &stsd.mp4a {
+				let desc = &mp4a
+					.esds
+					.as_ref()
+					.context("missing esds box for MP4a")?
+					.es_desc
+					.dec_config;
+				let codec_str = format!("mp4a.{:02x}.{}", desc.object_type_indication, desc.dec_specific.profile);
+
+				track["kind"] = json!("audio");
+				track["codec"] = json!(codec_str);
+				track["channel_count"] = json!(mp4a.channelcount);
+				track["sample_rate"] = json!(mp4a.samplerate.value());
+				track["sample_size"] = json!(mp4a.samplesize);
+
+				let bitrate = max(desc.max_bitrate, desc.avg_bitrate);
+				if bitrate > 0 {
+					track["bit_rate"] = json!(bitrate);
+				}
+			} else if let Some(vp09) = &stsd.vp09 {
+				// https://github.com/gpac/mp4box.js/blob/325741b592d910297bf609bc7c400fc76101077b/src/box-codecs.js#L238
+				let vpcc = &vp09.vpcc;
+				let codec_str = format!("vp09.0.{:02x}.{:02x}.{:02x}", vpcc.profile, vpcc.level, vpcc.bit_depth);
+
+				track["kind"] = json!("video");
+				track["codec"] = json!(codec_str);
+				track["width"] = json!(vp09.width); // no idea if this needs to be multiplied
+				track["height"] = json!(vp09.height); // no idea if this needs to be multiplied
+
+				// TODO Test if this actually works; I'm just guessing based on mp4box.js
+				anyhow::bail!("VP9 not yet supported")
+			} else {
+				// TODO add av01 support: https://github.com/gpac/mp4box.js/blob/325741b592d910297bf609bc7c400fc76101077b/src/box-codecs.js#L251
+				anyhow::bail!("unknown codec for track: {}", trak.tkhd.track_id);
+			}
+
+			tracks.push(track);
+		}
+
+		let catalog = json!({
+			"tracks": tracks
+		});
+
+		let catalog_str = serde_json::to_string_pretty(&catalog)?;
+		log::info!("catalog: {}", catalog_str);
+
+		// Create a single fragment for the segment.
+		let mut fragment = segment.create_fragment(fragment::Info {
+			sequence: VarInt::ZERO,
+			size: None, // Size is only needed when we have multiple fragments.
+		})?;
+
+		// Add the segment and add the fragment.
+		fragment.write_chunk(catalog_str.into())?;
+
+		Ok(())
+	}
+}
+
+// Read a full MP4 atom into a vector.
+async fn read_atom<R: AsyncReadExt + Unpin>(reader: &mut R) -> anyhow::Result<Vec<u8>> {
+	// Read the 8 bytes for the size + type
+	let mut buf = [0u8; 8];
+	reader.read_exact(&mut buf).await?;
+
+	// Convert the first 4 bytes into the size.
+	let size = u32::from_be_bytes(buf[0..4].try_into()?) as u64;
+
+	let mut raw = buf.to_vec();
+
+	let mut limit = match size {
+		// Runs until the end of the file.
+		0 => reader.take(u64::MAX),
+
+		// The next 8 bytes are the extended size to be used instead.
+		1 => {
+			reader.read_exact(&mut buf).await?;
+			let size_large = u64::from_be_bytes(buf);
+			anyhow::ensure!(size_large >= 16, "impossible extended box size: {}", size_large);
+
+			reader.take(size_large - 16)
+		}
+
+		2..=7 => {
+			anyhow::bail!("impossible box size: {}", size)
+		}
+
+		size => reader.take(size - 8),
+	};
+
+	// Append to the vector and return it.
+	let _read_bytes = limit.read_to_end(&mut raw).await?;
+
+	Ok(raw)
+}
+
+struct Track {
+	// The track we're producing
+	track: track::Publisher,
+
+	// The current segment
+	current: Option<fragment::Publisher>,
+
+	// The number of units per second.
+	timescale: u64,
+
+	// The number of segments produced.
+	sequence: u64,
+}
+
+impl Track {
+	fn new(track: track::Publisher, timescale: u64) -> Self {
+		Self {
+			track,
+			sequence: 0,
+			current: None,
+			timescale,
+		}
+	}
+
+	pub fn header(&mut self, raw: Vec<u8>, fragment: Fragment) -> anyhow::Result<()> {
+		if let Some(current) = self.current.as_mut() {
+			if !fragment.keyframe {
+				// Use the existing segment
+				current.write_chunk(raw.into())?;
+				return Ok(());
+			}
+		}
+
+		// Otherwise make a new segment
+
+		// Compute the timestamp in milliseconds.
+		// Overflows after 583 million years, so we're fine.
+		let timestamp: u32 = fragment
+			.timestamp(self.timescale)
+			.as_millis()
+			.try_into()
+			.context("timestamp too large")?;
+
+		// Create a new segment.
+		let mut segment = self.track.create_segment(segment::Info {
+			sequence: VarInt::try_from(self.sequence).context("sequence too large")?,
+
+			// Newer segments are higher priority
+			priority: u32::MAX.checked_sub(timestamp).context("priority too large")?,
+
+			// Delete segments after 10s.
+			expires: Some(time::Duration::from_secs(10)),
+		})?;
+
+		// Create a single fragment for the segment that we will keep appending.
+		let mut fragment = segment.create_fragment(fragment::Info {
+			sequence: VarInt::ZERO,
+			size: None,
+		})?;
+
+		self.sequence += 1;
+
+		// Insert the raw atom into the segment.
+		fragment.write_chunk(raw.into())?;
+
+		// Save for the next iteration
+		self.current = Some(fragment);
+
+		Ok(())
+	}
+
+	pub fn data(&mut self, raw: Vec<u8>) -> anyhow::Result<()> {
+		let fragment = self.current.as_mut().context("missing current fragment")?;
+		fragment.write_chunk(raw.into())?;
+
+		Ok(())
+	}
+}
+
+struct Fragment {
+	// The track for this fragment.
+	track: u32,
+
+	// The timestamp of the first sample in this fragment, in timescale units.
+	timestamp: u64,
+
+	// True if this fragment is a keyframe.
+	keyframe: bool,
+}
+
+impl Fragment {
+	fn new(moof: mp4::MoofBox) -> anyhow::Result<Self> {
+		// We can't split the mdat atom, so this is impossible to support
+		anyhow::ensure!(moof.trafs.len() == 1, "multiple tracks per moof atom");
+		let track = moof.trafs[0].tfhd.track_id;
+
+		// Parse the moof to get some timing information to sleep.
+		let timestamp = sample_timestamp(&moof).expect("couldn't find timestamp");
+
+		// Detect if we should start a new segment.
+		let keyframe = sample_keyframe(&moof);
+
+		Ok(Self {
+			track,
+			timestamp,
+			keyframe,
+		})
+	}
+
+	// Convert from timescale units to a duration.
+	fn timestamp(&self, timescale: u64) -> time::Duration {
+		time::Duration::from_millis(1000 * self.timestamp / timescale)
+	}
+}
+
+fn sample_timestamp(moof: &mp4::MoofBox) -> Option<u64> {
+	Some(moof.trafs.first()?.tfdt.as_ref()?.base_media_decode_time)
+}
+
+fn sample_keyframe(moof: &mp4::MoofBox) -> bool {
+	for traf in &moof.trafs {
+		// TODO trak default flags if this is None
+		let default_flags = traf.tfhd.default_sample_flags.unwrap_or_default();
+		let trun = match &traf.trun {
+			Some(t) => t,
+			None => return false,
+		};
+
+		for i in 0..trun.sample_count {
+			let mut flags = match trun.sample_flags.get(i as usize) {
+				Some(f) => *f,
+				None => default_flags,
+			};
+
+			if i == 0 && trun.first_sample_flags.is_some() {
+				flags = trun.first_sample_flags.unwrap();
+			}
+
+			// https://chromium.googlesource.com/chromium/src/media/+/master/formats/mp4/track_run_iterator.cc#177
+			let keyframe = (flags >> 24) & 0x3 == 0x2; // kSampleDependsOnNoOther
+			let non_sync = (flags >> 16) & 0x1 == 0x1; // kSampleIsNonSyncSample
+
+			if keyframe && !non_sync {
+				return true;
+			}
+		}
+	}
+
+	false
+}
+
+// Find the timescale for the given track.
+fn track_timescale(moov: &mp4::MoovBox, track_id: u32) -> u64 {
+	let trak = moov
+		.traks
+		.iter()
+		.find(|trak| trak.tkhd.track_id == track_id)
+		.expect("failed to find trak");
+
+	trak.mdia.mdhd.timescale as u64
+}

moq-quinn/Cargo.toml

@@ -1,42 +0,0 @@
-[package]
-name = "moq-quinn"
-description = "Media over QUIC"
-authors = ["Luke Curley"]
-repository = "https://github.com/kixelated/moq-rs"
-license = "MIT OR Apache-2.0"
-
-version = "0.1.0"
-edition = "2021"
-
-keywords = ["quic", "http3", "webtransport", "media", "live"]
-categories = ["multimedia", "network-programming", "web-programming"]
-
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]
-moq-transport = { path = "../moq-transport" }
-moq-warp = { path = "../moq-warp" }
-webtransport-generic = { path = "../../webtransport-rs/webtransport-generic", version = "0.3" }
-
-# QUIC
-quinn = "0.10"
-webtransport-quinn = { path = "../../webtransport-rs/webtransport-quinn", version = "0.4.2" }
-
-# Crypto
-ring = "0.16.20"
-rustls = "0.21.2"
-rustls-pemfile = "1.0.2"
-
-# Async stuff
-tokio = { version = "1.27", features = ["full"] }
-
-# Web server to serve the fingerprint
-warp = { version = "0.3.3", features = ["tls"] }
-hex = "0.4.3"
-
-# Logging
-clap = { version = "4.0", features = ["derive"] }
-log = { version = "0.4", features = ["std"] }
-env_logger = "0.9.3"
-anyhow = "1.0.70"

moq-quinn/src/main.rs

@@ -1,84 +0,0 @@
-use std::{fs, io, net, path, sync};
-
-use anyhow::Context;
-use clap::Parser;
-use ring::digest::{digest, SHA256};
-use warp::Filter;
-
-mod server;
-use server::*;
-
-/// Search for a pattern in a file and display the lines that contain it.
-#[derive(Parser, Clone)]
-struct Cli {
-	/// Listen on this address
-	#[arg(short, long, default_value = "[::]:4443")]
-	addr: net::SocketAddr,
-
-	/// Use the certificate file at this path
-	#[arg(short, long, default_value = "cert/localhost.crt")]
-	cert: path::PathBuf,
-
-	/// Use the private key at this path
-	#[arg(short, long, default_value = "cert/localhost.key")]
-	key: path::PathBuf,
-}
-
-#[tokio::main]
-async fn main() -> anyhow::Result<()> {
-	env_logger::init();
-
-	let args = Cli::parse();
-
-	// Create a web server to serve the fingerprint
-	let serve = serve_http(args.clone());
-
-	// Create a server to actually serve the media
-	let config = ServerConfig {
-		addr: args.addr,
-		cert: args.cert,
-		key: args.key,
-	};
-
-	let server = Server::new(config).context("failed to create server")?;
-
-	// Run all of the above
-	tokio::select! {
-		res = server.run() => res.context("failed to run server"),
-		res = serve => res.context("failed to run HTTP server"),
-	}
-}
-
-// Run a HTTP server using Warp
-// TODO remove this when Chrome adds support for self-signed certificates using WebTransport
-async fn serve_http(args: Cli) -> anyhow::Result<()> {
-	// Read the PEM certificate file
-	let crt = fs::File::open(&args.cert)?;
-	let mut crt = io::BufReader::new(crt);
-
-	// Parse the DER certificate
-	let certs = rustls_pemfile::certs(&mut crt)?;
-	let cert = certs.first().expect("no certificate found");
-
-	// Compute the SHA-256 digest
-	let fingerprint = digest(&SHA256, cert.as_ref());
-	let fingerprint = hex::encode(fingerprint.as_ref());
-	let fingerprint = sync::Arc::new(fingerprint);
-
-	let cors = warp::cors().allow_any_origin();
-
-	// What an annoyingly complicated way to serve a static String
-	// I spent a long time trying to find the exact way of cloning and dereferencing the Arc.
-	let routes = warp::path!("fingerprint")
-		.map(move || (*(fingerprint.clone())).clone())
-		.with(cors);
-
-	warp::serve(routes)
-		.tls()
-		.cert_path(args.cert)
-		.key_path(args.key)
-		.run(args.addr)
-		.await;
-
-	Ok(())
-}

moq-quinn/src/server.rs

@@ -1,116 +0,0 @@
-use std::{fs, io, net, path, sync, time};
-
-use anyhow::Context;
-
-use moq_warp::relay;
-use tokio::task::JoinSet;
-
-pub struct Server {
-	server: quinn::Endpoint,
-
-	// The media sources.
-	broker: relay::Broker,
-
-	// The active connections.
-	conns: JoinSet<anyhow::Result<()>>,
-}
-
-pub struct ServerConfig {
-	pub addr: net::SocketAddr,
-	pub cert: path::PathBuf,
-	pub key: path::PathBuf,
-}
-
-impl Server {
-	// Create a new server
-	pub fn new(config: ServerConfig) -> anyhow::Result<Self> {
-		// Read the PEM certificate chain
-		let certs = fs::File::open(config.cert).context("failed to open cert file")?;
-		let mut certs = io::BufReader::new(certs);
-		let certs = rustls_pemfile::certs(&mut certs)?
-			.into_iter()
-			.map(rustls::Certificate)
-			.collect();
-
-		// Read the PEM private key
-		let keys = fs::File::open(config.key).context("failed to open key file")?;
-		let mut keys = io::BufReader::new(keys);
-		let mut keys = rustls_pemfile::pkcs8_private_keys(&mut keys)?;
-
-		anyhow::ensure!(keys.len() == 1, "expected a single key");
-		let key = rustls::PrivateKey(keys.remove(0));
-
-		let mut tls_config = rustls::ServerConfig::builder()
-			.with_safe_default_cipher_suites()
-			.with_safe_default_kx_groups()
-			.with_protocol_versions(&[&rustls::version::TLS13])
-			.unwrap()
-			.with_no_client_auth()
-			.with_single_cert(certs, key)?;
-
-		tls_config.max_early_data_size = u32::MAX;
-		tls_config.alpn_protocols = vec![webtransport_quinn::ALPN.to_vec()];
-
-		let mut server_config = quinn::ServerConfig::with_crypto(sync::Arc::new(tls_config));
-
-		// Enable BBR congestion control
-		// TODO validate the implementation
-		let mut transport_config = quinn::TransportConfig::default();
-		transport_config.keep_alive_interval(Some(time::Duration::from_secs(2)));
-		transport_config.congestion_controller_factory(sync::Arc::new(quinn::congestion::BbrConfig::default()));
-
-		server_config.transport = sync::Arc::new(transport_config);
-		let server = quinn::Endpoint::server(server_config, config.addr)?;
-		let broker = relay::Broker::new();
-
-		let conns = JoinSet::new();
-
-		Ok(Self { server, broker, conns })
-	}
-
-	pub async fn run(mut self) -> anyhow::Result<()> {
-		loop {
-			tokio::select! {
-				res = self.server.accept() => {
-					let conn = res.context("failed to accept QUIC connection")?;
-					let broker = self.broker.clone();
-
-					self.conns.spawn(async move { Self::handle(conn, broker).await });
-				},
-				res = self.conns.join_next(), if !self.conns.is_empty() => {
-					let res = res.expect("no tasks").expect("task aborted");
-					if let Err(err) = res {
-						log::error!("connection terminated: {:?}", err);
-					}
-				},
-			}
-		}
-	}
-
-	async fn handle(conn: quinn::Connecting, broker: relay::Broker) -> anyhow::Result<()> {
-		// Wait for the QUIC connection to be established.
-		let conn = conn.await.context("failed to establish QUIC connection")?;
-
-		// Wait for the CONNECT request.
-		let request = webtransport_quinn::accept(conn)
-			.await
-			.context("failed to receive WebTransport request")?;
-
-		// TODO parse the request URI
-
-		// Accept the CONNECT request.
-		let session = request
-			.ok()
-			.await
-			.context("failed to respond to WebTransport request")?;
-
-		// Perform the MoQ handshake.
-		let session = moq_transport::Session::accept(session, moq_transport::setup::Role::Both)
-			.await
-			.context("failed to perform MoQ handshake")?;
-
-		// Run the relay code.
-		let session = relay::Session::new(session, broker);
-		session.run().await
-	}
-}

moq-relay/Cargo.toml

@@ -0,0 +1,51 @@
+[package]
+name = "moq-relay"
+description = "Media over QUIC"
+authors = ["Luke Curley"]
+repository = "https://github.com/kixelated/moq-rs"
+license = "MIT OR Apache-2.0"
+
+version = "0.1.0"
+edition = "2021"
+
+keywords = ["quic", "http3", "webtransport", "media", "live"]
+categories = ["multimedia", "network-programming", "web-programming"]
+
+[dependencies]
+moq-transport = { path = "../moq-transport" }
+moq-api = { path = "../moq-api" }
+
+# QUIC
+quinn = "0.10"
+webtransport-quinn = "0.6"
+#webtransport-quinn = { path = "../../webtransport-rs/webtransport-quinn" }
+url = "2"
+
+# Crypto
+ring = "0.16"
+rustls = { version = "0.21", features = ["dangerous_configuration"] }
+rustls-pemfile = "1"
+rustls-native-certs = "0.6"
+webpki = "0.22"
+
+# Async stuff
+tokio = { version = "1", features = ["full"] }
+
+# Web server to serve the fingerprint
+axum = { version = "0.6", features = ["tokio"] }
+axum-server = { version = "0.5", features = ["tls-rustls"] }
+hex = "0.4"
+tower-http = { version = "0.4", features = ["cors"] }
+
+# Error handling
+anyhow = { version = "1", features = ["backtrace"] }
+thiserror = "1"
+
+# CLI
+clap = { version = "4", features = ["derive"] }
+
+# Logging
+log = { version = "0.4", features = ["std"] }
+env_logger = "0.9"
+tracing = "0.1"
+tracing-subscriber = "0.3"

moq-relay/README.md

@@ -0,0 +1,17 @@
+# moq-relay
+
+A server that connects publishing clients to subscribing clients.
+All subscriptions are deduplicated and cached, so that a single publisher can serve many subscribers.
+
+## Usage
+
+The publisher must choose a unique name for their broadcast, sent as the WebTransport path when connecting to the server.
+We currently do a dumb string comparison, so capatilization matters as do slashes.
+
+For example: `CONNECT https://relay.quic.video/BigBuckBunny`
+
+The MoqTransport handshake includes a `role` parameter, which must be `publisher` or `subscriber`.
+The specification allows a `both` role but you'll get an error.
+
+You can have one publisher and any number of subscribers connected to the same path.
+If the publisher disconnects, then all subscribers receive an error and will not get updates, even if a new publisher reuses the path.

moq-relay/src/config.rs

@@ -0,0 +1,55 @@
+use std::{net, path};
+use url::Url;
+
+use clap::Parser;
+
+/// Search for a pattern in a file and display the lines that contain it.
+#[derive(Parser, Clone)]
+pub struct Config {
+	/// Listen on this address
+	#[arg(long, default_value = "[::]:4443")]
+	pub listen: net::SocketAddr,
+
+	/// Use the certificates at this path, encoded as PEM.
+	///
+	/// You can use this option multiple times for multiple certificates.
+	/// The first match for the provided SNI will be used, otherwise the last cert will be used.
+	/// You also need to provide the private key multiple times via `key``.
+	#[arg(long)]
+	pub tls_cert: Vec<path::PathBuf>,
+
+	/// Use the private key at this path, encoded as PEM.
+	///
+	/// There must be a key for every certificate provided via `cert`.
+	#[arg(long)]
+	pub tls_key: Vec<path::PathBuf>,
+
+	/// Use the TLS root at this path, encoded as PEM.
+	///
+	/// This value can be provided multiple times for multiple roots.
+	/// If this is empty, system roots will be used instead
+	#[arg(long)]
+	pub tls_root: Vec<path::PathBuf>,
+
+	/// Danger: Disable TLS certificate verification.
+	///
+	/// Fine for local development and between relays, but should be used in caution in production.
+	#[arg(long)]
+	pub tls_disable_verify: bool,
+
+	/// Optional: Use the moq-api via HTTP to store origin information.
+	#[arg(long)]
+	pub api: Option<Url>,
+
+	/// Our internal address which we advertise to other origins.
+	/// We use QUIC, so the certificate must be valid for this address.
+	/// This needs to be prefixed with https:// to use WebTransport.
+	/// This is only used when --api is set and only for publishing broadcasts.
+	#[arg(long)]
+	pub api_node: Option<Url>,
+
+	/// Enable development mode.
+	/// Currently, this only listens on HTTPS and serves /fingerprint, for self-signed certificates
+	#[arg(long, action)]
+	pub dev: bool,
+}

moq-relay/src/error.rs

@@ -0,0 +1,51 @@
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum RelayError {
+	#[error("transport error: {0}")]
+	Transport(#[from] moq_transport::session::SessionError),
+
+	#[error("cache error: {0}")]
+	Cache(#[from] moq_transport::cache::CacheError),
+
+	#[error("api error: {0}")]
+	MoqApi(#[from] moq_api::ApiError),
+
+	#[error("url error: {0}")]
+	Url(#[from] url::ParseError),
+
+	#[error("webtransport client error: {0}")]
+	WebTransportClient(#[from] webtransport_quinn::ClientError),
+
+	#[error("webtransport server error: {0}")]
+	WebTransportServer(#[from] webtransport_quinn::ServerError),
+
+	#[error("missing node")]
+	MissingNode,
+}
+
+impl moq_transport::MoqError for RelayError {
+	fn code(&self) -> u32 {
+		match self {
+			Self::Transport(err) => err.code(),
+			Self::Cache(err) => err.code(),
+			Self::MoqApi(_err) => 504,
+			Self::Url(_) => 500,
+			Self::MissingNode => 500,
+			Self::WebTransportClient(_) => 504,
+			Self::WebTransportServer(_) => 500,
+		}
+	}
+
+	fn reason(&self) -> String {
+		match self {
+			Self::Transport(err) => format!("transport error: {}", err.reason()),
+			Self::Cache(err) => format!("cache error: {}", err.reason()),
+			Self::MoqApi(err) => format!("api error: {}", err),
+			Self::Url(err) => format!("url error: {}", err),
+			Self::MissingNode => "missing node".to_owned(),
+			Self::WebTransportServer(err) => format!("upstream server error: {}", err),
+			Self::WebTransportClient(err) => format!("upstream client error: {}", err),
+		}
+	}
+}

moq-relay/src/main.rs

@@ -0,0 +1,51 @@
+use anyhow::Context;
+use clap::Parser;
+
+mod config;
+mod error;
+mod origin;
+mod quic;
+mod session;
+mod tls;
+mod web;
+
+pub use config::*;
+pub use error::*;
+pub use origin::*;
+pub use quic::*;
+pub use session::*;
+pub use tls::*;
+pub use web::*;
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+	env_logger::init();
+
+	// Disable tracing so we don't get a bunch of Quinn spam.
+	let tracer = tracing_subscriber::FmtSubscriber::builder()
+		.with_max_level(tracing::Level::WARN)
+		.finish();
+	tracing::subscriber::set_global_default(tracer).unwrap();
+
+	let config = Config::parse();
+	let tls = Tls::load(&config)?;
+
+	// Create a QUIC server for media.
+	let quic = Quic::new(config.clone(), tls.clone())
+		.await
+		.context("failed to create server")?;
+
+	// Create the web server if the --dev flag was set.
+	// This is currently only useful in local development so it's not enabled by default.
+	if config.dev {
+		let web = Web::new(config, tls);
+
+		// Unfortunately we can't use preconditions because Tokio still executes the branch; just ignore the result
+		tokio::select! {
+			res = quic.serve() => res.context("failed to run quic server"),
+			res = web.serve() => res.context("failed to run web server"),
+		}
+	} else {
+		quic.serve().await.context("failed to run quic server")
+	}
+}

moq-relay/src/origin.rs

@@ -0,0 +1,216 @@
+use std::ops::{Deref, DerefMut};
+use std::{
+	collections::HashMap,
+	sync::{Arc, Mutex, Weak},
+};
+
+use moq_api::ApiError;
+use moq_transport::cache::{broadcast, CacheError};
+use url::Url;
+
+use tokio::time;
+
+use crate::RelayError;
+
+#[derive(Clone)]
+pub struct Origin {
+	// An API client used to get/set broadcasts.
+	// If None then we never use a remote origin.
+	// TODO: Stub this out instead.
+	api: Option<moq_api::Client>,
+
+	// The internal address of our node.
+	// If None then we can never advertise ourselves as an origin.
+	// TODO: Stub this out instead.
+	node: Option<Url>,
+
+	// A map of active broadcasts by ID.
+	cache: Arc<Mutex<HashMap<String, Weak<Subscriber>>>>,
+
+	// A QUIC endpoint we'll use to fetch from other origins.
+	quic: quinn::Endpoint,
+}
+
+impl Origin {
+	pub fn new(api: Option<moq_api::Client>, node: Option<Url>, quic: quinn::Endpoint) -> Self {
+		Self {
+			api,
+			node,
+			cache: Default::default(),
+			quic,
+		}
+	}
+
+	/// Create a new broadcast with the given ID.
+	///
+	/// Publisher::run needs to be called to periodically refresh the origin cache.
+	pub async fn publish(&mut self, id: &str) -> Result<Publisher, RelayError> {
+		let (publisher, subscriber) = broadcast::new(id);
+
+		let subscriber = {
+			let mut cache = self.cache.lock().unwrap();
+
+			// Check if the broadcast already exists.
+			// TODO This is racey, because a new publisher could be created while existing subscribers are still active.
+			if cache.contains_key(id) {
+				return Err(CacheError::Duplicate.into());
+			}
+
+			// Create subscriber that will remove from the cache when dropped.
+			let subscriber = Arc::new(Subscriber {
+				broadcast: subscriber,
+				origin: self.clone(),
+			});
+
+			cache.insert(id.to_string(), Arc::downgrade(&subscriber));
+
+			subscriber
+		};
+
+		// Create a publisher that constantly updates itself as the origin in moq-api.
+		// It holds a reference to the subscriber to prevent dropping early.
+		let mut publisher = Publisher {
+			broadcast: publisher,
+			subscriber,
+			api: None,
+		};
+
+		// Insert the publisher into the database.
+		if let Some(api) = self.api.as_mut() {
+			// Make a URL for the broadcast.
+			let url = self.node.as_ref().ok_or(RelayError::MissingNode)?.clone().join(id)?;
+			let origin = moq_api::Origin { url };
+			api.set_origin(id, &origin).await?;
+
+			// Refresh every 5 minutes
+			publisher.api = Some((api.clone(), origin));
+		}
+
+		Ok(publisher)
+	}
+
+	pub fn subscribe(&self, id: &str) -> Arc<Subscriber> {
+		let mut cache = self.cache.lock().unwrap();
+
+		if let Some(broadcast) = cache.get(id) {
+			if let Some(broadcast) = broadcast.upgrade() {
+				return broadcast;
+			}
+		}
+
+		let (publisher, subscriber) = broadcast::new(id);
+		let subscriber = Arc::new(Subscriber {
+			broadcast: subscriber,
+			origin: self.clone(),
+		});
+
+		cache.insert(id.to_string(), Arc::downgrade(&subscriber));
+
+		let mut this = self.clone();
+		let id = id.to_string();
+
+		// Rather than fetching from the API and connecting via QUIC inline, we'll spawn a task to do it.
+		// This way we could stop polling this session and it won't impact other session.
+		// It also means we'll only connect the API and QUIC once if N subscribers suddenly show up.
+		// However, the downside is that we don't return an error immediately.
+		// If that's important, it can be done but it gets a bit racey.
+		tokio::spawn(async move {
+			if let Err(err) = this.serve(&id, publisher).await {
+				log::warn!("failed to serve remote broadcast: id={} err={}", id, err);
+			}
+		});
+
+		subscriber
+	}
+
+	async fn serve(&mut self, id: &str, publisher: broadcast::Publisher) -> Result<(), RelayError> {
+		log::debug!("finding origin: id={}", id);
+
+		// Fetch the origin from the API.
+		let origin = self
+			.api
+			.as_mut()
+			.ok_or(CacheError::NotFound)?
+			.get_origin(id)
+			.await?
+			.ok_or(CacheError::NotFound)?;
+
+		log::debug!("fetching from origin: id={} url={}", id, origin.url);
+
+		// Establish the webtransport session.
+		let session = webtransport_quinn::connect(&self.quic, &origin.url).await?;
+		let session = moq_transport::session::Client::subscriber(session, publisher).await?;
+
+		session.run().await?;
+
+		Ok(())
+	}
+}
+
+pub struct Subscriber {
+	pub broadcast: broadcast::Subscriber,
+
+	origin: Origin,
+}
+
+impl Drop for Subscriber {
+	fn drop(&mut self) {
+		self.origin.cache.lock().unwrap().remove(&self.broadcast.id);
+	}
+}
+
+impl Deref for Subscriber {
+	type Target = broadcast::Subscriber;
+
+	fn deref(&self) -> &Self::Target {
+		&self.broadcast
+	}
+}
+
+pub struct Publisher {
+	pub broadcast: broadcast::Publisher,
+
+	api: Option<(moq_api::Client, moq_api::Origin)>,
+
+	#[allow(dead_code)]
+	subscriber: Arc<Subscriber>,
+}
+
+impl Publisher {
+	pub async fn run(&mut self) -> Result<(), ApiError> {
+		// Every 5m tell the API we're still alive.
+		// TODO don't hard-code these values
+		let mut interval = time::interval(time::Duration::from_secs(60 * 5));
+
+		loop {
+			if let Some((api, origin)) = self.api.as_mut() {
+				api.patch_origin(&self.broadcast.id, origin).await?;
+			}
+
+			// TODO move to start of loop; this is just for testing
+			interval.tick().await;
+		}
+	}
+
+	pub async fn close(&mut self) -> Result<(), ApiError> {
+		if let Some((api, _)) = self.api.as_mut() {
+			api.delete_origin(&self.broadcast.id).await?;
+		}
+
+		Ok(())
+	}
+}
+
+impl Deref for Publisher {
+	type Target = broadcast::Publisher;
+
+	fn deref(&self) -> &Self::Target {
+		&self.broadcast
+	}
+}
+
+impl DerefMut for Publisher {
+	fn deref_mut(&mut self) -> &mut Self::Target {
+		&mut self.broadcast
+	}
+}

moq-relay/src/quic.rs

@@ -0,0 +1,85 @@
+use std::{sync::Arc, time};
+
+use anyhow::Context;
+
+use tokio::task::JoinSet;
+
+use crate::{Config, Origin, Session, Tls};
+
+pub struct Quic {
+	quic: quinn::Endpoint,
+
+	// The active connections.
+	conns: JoinSet<anyhow::Result<()>>,
+
+	// The map of active broadcasts by path.
+	origin: Origin,
+}
+
+impl Quic {
+	// Create a QUIC endpoint that can be used for both clients and servers.
+	pub async fn new(config: Config, tls: Tls) -> anyhow::Result<Self> {
+		let mut client_config = tls.client.clone();
+		let mut server_config = tls.server.clone();
+		client_config.alpn_protocols = vec![webtransport_quinn::ALPN.to_vec()];
+		server_config.alpn_protocols = vec![webtransport_quinn::ALPN.to_vec()];
+
+		// Enable BBR congestion control
+		// TODO validate the implementation
+		let mut transport_config = quinn::TransportConfig::default();
+		transport_config.max_idle_timeout(Some(time::Duration::from_secs(10).try_into().unwrap()));
+		transport_config.keep_alive_interval(Some(time::Duration::from_secs(4))); // TODO make this smarter
+		transport_config.congestion_controller_factory(Arc::new(quinn::congestion::BbrConfig::default()));
+		transport_config.mtu_discovery_config(None); // Disable MTU discovery
+		let transport_config = Arc::new(transport_config);
+
+		let mut client_config = quinn::ClientConfig::new(Arc::new(client_config));
+		let mut server_config = quinn::ServerConfig::with_crypto(Arc::new(server_config));
+		server_config.transport_config(transport_config.clone());
+		client_config.transport_config(transport_config);
+
+		// There's a bit more boilerplate to make a generic endpoint.
+		let runtime = quinn::default_runtime().context("no async runtime")?;
+		let endpoint_config = quinn::EndpointConfig::default();
+		let socket = std::net::UdpSocket::bind(config.listen).context("failed to bind UDP socket")?;
+
+		// Create the generic QUIC endpoint.
+		let mut quic = quinn::Endpoint::new(endpoint_config, Some(server_config), socket, runtime)
+			.context("failed to create QUIC endpoint")?;
+		quic.set_default_client_config(client_config);
+
+		let api = config.api.map(|url| {
+			log::info!("using moq-api: url={}", url);
+			moq_api::Client::new(url)
+		});
+
+		if let Some(ref node) = config.api_node {
+			log::info!("advertising origin: url={}", node);
+		}
+
+		let origin = Origin::new(api, config.api_node, quic.clone());
+		let conns = JoinSet::new();
+
+		Ok(Self { quic, origin, conns })
+	}
+
+	pub async fn serve(mut self) -> anyhow::Result<()> {
+		log::info!("listening on {}", self.quic.local_addr()?);
+
+		loop {
+			tokio::select! {
+				res = self.quic.accept() => {
+					let conn = res.context("failed to accept QUIC connection")?;
+					let mut session = Session::new(self.origin.clone());
+					self.conns.spawn(async move { session.run(conn).await });
+				},
+				res = self.conns.join_next(), if !self.conns.is_empty() => {
+					let res = res.expect("no tasks").expect("task aborted");
+					if let Err(err) = res {
+						log::warn!("connection terminated: {:?}", err);
+					}
+				},
+			}
+		}
+	}
+}

moq-relay/src/session.rs

@@ -0,0 +1,111 @@
+use anyhow::Context;
+
+use moq_transport::{session::Request, setup::Role, MoqError};
+
+use crate::Origin;
+
+#[derive(Clone)]
+pub struct Session {
+	origin: Origin,
+}
+
+impl Session {
+	pub fn new(origin: Origin) -> Self {
+		Self { origin }
+	}
+
+	pub async fn run(&mut self, conn: quinn::Connecting) -> anyhow::Result<()> {
+		log::debug!("received QUIC handshake: ip={:?}", conn.remote_address());
+
+		// Wait for the QUIC connection to be established.
+		let conn = conn.await.context("failed to establish QUIC connection")?;
+
+		log::debug!(
+			"established QUIC connection: ip={:?} id={}",
+			conn.remote_address(),
+			conn.stable_id()
+		);
+		let id = conn.stable_id();
+
+		// Wait for the CONNECT request.
+		let request = webtransport_quinn::accept(conn)
+			.await
+			.context("failed to receive WebTransport request")?;
+
+		// Strip any leading and trailing slashes to get the broadcast name.
+		let path = request.url().path().trim_matches('/').to_string();
+
+		log::debug!("received WebTransport CONNECT: id={} path={}", id, path);
+
+		// Accept the CONNECT request.
+		let session = request
+			.ok()
+			.await
+			.context("failed to respond to WebTransport request")?;
+
+		// Perform the MoQ handshake.
+		let request = moq_transport::session::Server::accept(session)
+			.await
+			.context("failed to accept handshake")?;
+
+		log::debug!("received MoQ SETUP: id={} role={:?}", id, request.role());
+
+		let role = request.role();
+
+		match role {
+			Role::Publisher => {
+				if let Err(err) = self.serve_publisher(id, request, &path).await {
+					log::warn!("error serving publisher: id={} path={} err={:#?}", id, path, err);
+				}
+			}
+			Role::Subscriber => {
+				if let Err(err) = self.serve_subscriber(id, request, &path).await {
+					log::warn!("error serving subscriber: id={} path={} err={:#?}", id, path, err);
+				}
+			}
+			Role::Both => {
+				log::warn!("role both not supported: id={}", id);
+				request.reject(300);
+			}
+		};
+
+		log::debug!("closing connection: id={}", id);
+
+		Ok(())
+	}
+
+	async fn serve_publisher(&mut self, id: usize, request: Request, path: &str) -> anyhow::Result<()> {
+		log::info!("serving publisher: id={}, path={}", id, path);
+
+		let mut origin = match self.origin.publish(path).await {
+			Ok(origin) => origin,
+			Err(err) => {
+				request.reject(err.code());
+				return Err(err.into());
+			}
+		};
+
+		let session = request.subscriber(origin.broadcast.clone()).await?;
+
+		tokio::select! {
+			_ = session.run() => origin.close().await?,
+			_ = origin.run() => (), // TODO send error to session
+		};
+
+		Ok(())
+	}
+
+	async fn serve_subscriber(&mut self, id: usize, request: Request, path: &str) -> anyhow::Result<()> {
+		log::info!("serving subscriber: id={} path={}", id, path);
+
+		let subscriber = self.origin.subscribe(path);
+
+		let session = request.publisher(subscriber.broadcast.clone()).await?;
+		session.run().await?;
+
+		// Make sure this doesn't get dropped too early
+		drop(subscriber);
+
+		Ok(())
+	}
+}

moq-relay/src/tls.rs

@@ -0,0 +1,182 @@
+use anyhow::Context;
+use ring::digest::{digest, SHA256};
+use rustls::server::{ClientHello, ResolvesServerCert};
+use rustls::sign::CertifiedKey;
+use rustls::{Certificate, PrivateKey, RootCertStore};
+use std::io::{self, Cursor, Read};
+use std::path;
+use std::sync::Arc;
+use std::{fs, time};
+use webpki::{DnsNameRef, EndEntityCert};
+
+use crate::Config;
+
+#[derive(Clone)]
+pub struct Tls {
+	pub server: rustls::ServerConfig,
+	pub client: rustls::ClientConfig,
+	pub fingerprints: Vec<String>,
+}
+
+impl Tls {
+	pub fn load(config: &Config) -> anyhow::Result<Self> {
+		let mut serve = ServeCerts::default();
+
+		// Load the certificate and key files based on their index.
+		anyhow::ensure!(
+			config.tls_cert.len() == config.tls_key.len(),
+			"--tls-cert and --tls-key counts differ"
+		);
+		for (chain, key) in config.tls_cert.iter().zip(config.tls_key.iter()) {
+			serve.load(chain, key)?;
+		}
+
+		// Create a list of acceptable root certificates.
+		let mut roots = RootCertStore::empty();
+
+		if config.tls_root.is_empty() {
+			// Add the platform's native root certificates.
+			for cert in rustls_native_certs::load_native_certs().context("could not load platform certs")? {
+				roots.add(&Certificate(cert.0)).context("failed to add root cert")?;
+			}
+		} else {
+			// Add the specified root certificates.
+			for root in &config.tls_root {
+				let root = fs::File::open(root).context("failed to open root cert file")?;
+				let mut root = io::BufReader::new(root);
+				let root = rustls_pemfile::certs(&mut root).context("failed to read root cert")?;
+				anyhow::ensure!(root.len() == 1, "expected a single root cert");
+				let root = Certificate(root[0].to_owned());
+
+				roots.add(&root).context("failed to add root cert")?;
+			}
+		}
+
+		// Create the TLS configuration we'll use as a client (relay -> relay)
+		let mut client = rustls::ClientConfig::builder()
+			.with_safe_defaults()
+			.with_root_certificates(roots)
+			.with_no_client_auth();
+
+		// Allow disabling TLS verification altogether.
+		if config.tls_disable_verify {
+			let noop = NoCertificateVerification {};
+			client.dangerous().set_certificate_verifier(Arc::new(noop));
+		}
+
+		let fingerprints = serve.fingerprints();
+
+		// Create the TLS configuration we'll use as a server (relay <- browser)
+		let server = rustls::ServerConfig::builder()
+			.with_safe_defaults()
+			.with_no_client_auth()
+			.with_cert_resolver(Arc::new(serve));
+
+		let certs = Self {
+			server,
+			client,
+			fingerprints,
+		};
+
+		Ok(certs)
+	}
+}
+
+#[derive(Default)]
+struct ServeCerts {
+	list: Vec<Arc<CertifiedKey>>,
+}
+
+impl ServeCerts {
+	// Load a certificate and cooresponding key from a file
+	pub fn load(&mut self, chain: &path::PathBuf, key: &path::PathBuf) -> anyhow::Result<()> {
+		// Read the PEM certificate chain
+		let chain = fs::File::open(chain).context("failed to open cert file")?;
+		let mut chain = io::BufReader::new(chain);
+
+		let chain: Vec<Certificate> = rustls_pemfile::certs(&mut chain)?
+			.into_iter()
+			.map(Certificate)
+			.collect();
+
+		anyhow::ensure!(!chain.is_empty(), "could not find certificate");
+
+		// Read the PEM private key
+		let mut keys = fs::File::open(key).context("failed to open key file")?;
+
+		// Read the keys into a Vec so we can parse it twice.
+		let mut buf = Vec::new();
+		keys.read_to_end(&mut buf)?;
+
+		// Try to parse a PKCS#8 key
+		// -----BEGIN PRIVATE KEY-----
+		let mut keys = rustls_pemfile::pkcs8_private_keys(&mut Cursor::new(&buf))?;
+
+		// Try again but with EC keys this time
+		// -----BEGIN EC PRIVATE KEY-----
+		if keys.is_empty() {
+			keys = rustls_pemfile::ec_private_keys(&mut Cursor::new(&buf))?
+		};
+
+		anyhow::ensure!(!keys.is_empty(), "could not find private key");
+		anyhow::ensure!(keys.len() < 2, "expected a single key");
+
+		let key = PrivateKey(keys.remove(0));
+		let key = rustls::sign::any_supported_type(&key)?;
+
+		let certified = Arc::new(CertifiedKey::new(chain, key));
+		self.list.push(certified);
+
+		Ok(())
+	}
+
+	// Return the SHA256 fingerprint of our certificates.
+	pub fn fingerprints(&self) -> Vec<String> {
+		self.list
+			.iter()
+			.map(|ck| {
+				let fingerprint = digest(&SHA256, ck.cert[0].as_ref());
+				let fingerprint = hex::encode(fingerprint.as_ref());
+				fingerprint
+			})
+			.collect()
+	}
+}
+
+impl ResolvesServerCert for ServeCerts {
+	fn resolve(&self, client_hello: ClientHello<'_>) -> Option<Arc<CertifiedKey>> {
+		if let Some(name) = client_hello.server_name() {
+			if let Ok(dns_name) = DnsNameRef::try_from_ascii_str(name) {
+				for ck in &self.list {
+					// TODO I gave up on caching the parsed result because of lifetime hell.
+					// If this shows up on benchmarks, somebody should fix it.
+					let leaf = ck.cert.first().expect("missing certificate");
+					let parsed = EndEntityCert::try_from(leaf.0.as_ref()).expect("failed to parse certificate");
+
+					if parsed.verify_is_valid_for_dns_name(dns_name).is_ok() {
+						return Some(ck.clone());
+					}
+				}
+			}
+		}
+
+		// Default to the last certificate if we couldn't find one.
+		self.list.last().cloned()
+	}
+}
+
+pub struct NoCertificateVerification {}
+
+impl rustls::client::ServerCertVerifier for NoCertificateVerification {
+	fn verify_server_cert(
+		&self,
+		_end_entity: &rustls::Certificate,
+		_intermediates: &[rustls::Certificate],
+		_server_name: &rustls::ServerName,
+		_scts: &mut dyn Iterator<Item = &[u8]>,
+		_ocsp_response: &[u8],
+		_now: time::SystemTime,
+	) -> Result<rustls::client::ServerCertVerified, rustls::Error> {
+		Ok(rustls::client::ServerCertVerified::assertion())
+	}
+}

moq-relay/src/web.rs

@@ -0,0 +1,44 @@
+use std::sync::Arc;
+
+use axum::{extract::State, http::Method, response::IntoResponse, routing::get, Router};
+use axum_server::{tls_rustls::RustlsAcceptor, Server};
+use tower_http::cors::{Any, CorsLayer};
+
+use crate::{Config, Tls};
+
+// Run a HTTP server using Axum
+// TODO remove this when Chrome adds support for self-signed certificates using WebTransport
+pub struct Web {
+	app: Router,
+	server: Server<RustlsAcceptor>,
+}
+
+impl Web {
+	pub fn new(config: Config, tls: Tls) -> Self {
+		// Get the first certificate's fingerprint.
+		// TODO serve all of them so we can support multiple signature algorithms.
+		let fingerprint = tls.fingerprints.first().expect("missing certificate").clone();
+
+		let mut tls_config = tls.server.clone();
+		tls_config.alpn_protocols = vec![b"h2".to_vec(), b"http/1.1".to_vec()];
+		let tls_config = axum_server::tls_rustls::RustlsConfig::from_config(Arc::new(tls_config));
+
+		let app = Router::new()
+			.route("/fingerprint", get(serve_fingerprint))
+			.layer(CorsLayer::new().allow_origin(Any).allow_methods([Method::GET]))
+			.with_state(fingerprint);
+
+		let server = axum_server::bind_rustls(config.listen, tls_config);
+
+		Self { app, server }
+	}
+
+	pub async fn serve(self) -> anyhow::Result<()> {
+		self.server.serve(self.app.into_make_service()).await?;
+		Ok(())
+	}
+}
+
+async fn serve_fingerprint(State(fingerprint): State<String>) -> impl IntoResponse {
+	fingerprint
+}

moq-transport/Cargo.toml

@@ -5,7 +5,7 @@ authors = ["Luke Curley"]
 repository = "https://github.com/kixelated/moq-rs"
 license = "MIT OR Apache-2.0"
 
-version = "0.1.0"
+version = "0.2.0"
 edition = "2021"
 
 keywords = ["quic", "http3", "webtransport", "media", "live"]
@@ -17,6 +17,13 @@ categories = ["multimedia", "network-programming", "web-programming"]
 [dependencies]
 bytes = "1"
 thiserror = "1"
-anyhow = "1"
+tokio = { version = "1", features = ["macros", "io-util", "sync"] }
-webtransport-generic = { path = "../../webtransport-rs/webtransport-generic", version = "0.3" }
+log = "0.4"
-tokio = { version = "1.27", features = ["macros", "io-util"] }
+indexmap = "2"
+
+quinn = "0.10"
+webtransport-quinn = "0.6"
+#webtransport-quinn = { path = "../../webtransport-rs/webtransport-quinn" }
+
+async-trait = "0.1"
+paste = "1"

moq-transport/README.md

@@ -0,0 +1,10 @@
+[![Documentation](https://docs.rs/moq-transport/badge.svg)](https://docs.rs/moq-transport/)
+[![Crates.io](https://img.shields.io/crates/v/moq-transport.svg)](https://crates.io/crates/moq-transport)
+[![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](LICENSE-MIT)
+
+# moq-transport
+
+A Rust implementation of the proposed IETF standard.
+
+[Specification](https://datatracker.ietf.org/doc/draft-ietf-moq-transport/)
+[Github](https://github.com/moq-wg/moq-transport)

moq-transport/src/cache/broadcast.rs

@@ -0,0 +1,262 @@
+//! A broadcast is a collection of tracks, split into two handles: [Publisher] and [Subscriber].
+//!
+//! The [Publisher] can create tracks, either manually or on request.
+//! It receives all requests by a [Subscriber] for a tracks that don't exist.
+//! The simplest implementation is to close every unknown track with [CacheError::NotFound].
+//!
+//! A [Subscriber] can request tracks by name.
+//! If the track already exists, it will be returned.
+//! If the track doesn't exist, it will be sent to [Unknown] to be handled.
+//! A [Subscriber] can be cloned to create multiple subscriptions.
+//!
+//! The broadcast is automatically closed with [CacheError::Closed] when [Publisher] is dropped, or all [Subscriber]s are dropped.
+use std::{
+	collections::{hash_map, HashMap, VecDeque},
+	fmt,
+	ops::Deref,
+	sync::Arc,
+};
+
+use super::{track, CacheError, Watch};
+
+/// Create a new broadcast.
+pub fn new(id: &str) -> (Publisher, Subscriber) {
+	let state = Watch::new(State::default());
+	let info = Arc::new(Info { id: id.to_string() });
+
+	let publisher = Publisher::new(state.clone(), info.clone());
+	let subscriber = Subscriber::new(state, info);
+
+	(publisher, subscriber)
+}
+
+/// Static information about a broadcast.
+#[derive(Debug)]
+pub struct Info {
+	pub id: String,
+}
+
+/// Dynamic information about the broadcast.
+#[derive(Debug)]
+struct State {
+	tracks: HashMap<String, track::Subscriber>,
+	requested: VecDeque<track::Publisher>,
+	closed: Result<(), CacheError>,
+}
+
+impl State {
+	pub fn get(&self, name: &str) -> Result<Option<track::Subscriber>, CacheError> {
+		// Don't check closed, so we can return from cache.
+		Ok(self.tracks.get(name).cloned())
+	}
+
+	pub fn insert(&mut self, track: track::Subscriber) -> Result<(), CacheError> {
+		self.closed.clone()?;
+
+		match self.tracks.entry(track.name.clone()) {
+			hash_map::Entry::Occupied(_) => return Err(CacheError::Duplicate),
+			hash_map::Entry::Vacant(v) => v.insert(track),
+		};
+
+		Ok(())
+	}
+
+	pub fn request(&mut self, name: &str) -> Result<track::Subscriber, CacheError> {
+		self.closed.clone()?;
+
+		// Create a new track.
+		let (publisher, subscriber) = track::new(name);
+
+		// Insert the track into our Map so we deduplicate future requests.
+		self.tracks.insert(name.to_string(), subscriber.clone());
+
+		// Send the track to the Publisher to handle.
+		self.requested.push_back(publisher);
+
+		Ok(subscriber)
+	}
+
+	pub fn has_next(&self) -> Result<bool, CacheError> {
+		// Check if there's any elements in the queue before checking closed.
+		if !self.requested.is_empty() {
+			return Ok(true);
+		}
+
+		self.closed.clone()?;
+		Ok(false)
+	}
+
+	pub fn next(&mut self) -> track::Publisher {
+		// We panic instead of erroring to avoid a nasty wakeup loop if you don't call has_next first.
+		self.requested.pop_front().expect("no entry in queue")
+	}
+
+	pub fn close(&mut self, err: CacheError) -> Result<(), CacheError> {
+		self.closed.clone()?;
+		self.closed = Err(err);
+		Ok(())
+	}
+}
+
+impl Default for State {
+	fn default() -> Self {
+		Self {
+			tracks: HashMap::new(),
+			closed: Ok(()),
+			requested: VecDeque::new(),
+		}
+	}
+}
+
+/// Publish new tracks for a broadcast by name.
+// TODO remove Clone
+#[derive(Clone)]
+pub struct Publisher {
+	state: Watch<State>,
+	info: Arc<Info>,
+	_dropped: Arc<Dropped>,
+}
+
+impl Publisher {
+	fn new(state: Watch<State>, info: Arc<Info>) -> Self {
+		let _dropped = Arc::new(Dropped::new(state.clone()));
+		Self { state, info, _dropped }
+	}
+
+	/// Create a new track with the given name, inserting it into the broadcast.
+	pub fn create_track(&mut self, name: &str) -> Result<track::Publisher, CacheError> {
+		let (publisher, subscriber) = track::new(name);
+		self.state.lock_mut().insert(subscriber)?;
+		Ok(publisher)
+	}
+
+	/// Insert a track into the broadcast.
+	pub fn insert_track(&mut self, track: track::Subscriber) -> Result<(), CacheError> {
+		self.state.lock_mut().insert(track)
+	}
+
+	/// Block until the next track requested by a subscriber.
+	pub async fn next_track(&mut self) -> Result<track::Publisher, CacheError> {
+		loop {
+			let notify = {
+				let state = self.state.lock();
+				if state.has_next()? {
+					return Ok(state.into_mut().next());
+				}
+
+				state.changed()
+			};
+
+			notify.await;
+		}
+	}
+
+	/// Close the broadcast with an error.
+	pub fn close(self, err: CacheError) -> Result<(), CacheError> {
+		self.state.lock_mut().close(err)
+	}
+}
+
+impl Deref for Publisher {
+	type Target = Info;
+
+	fn deref(&self) -> &Self::Target {
+		&self.info
+	}
+}
+
+impl fmt::Debug for Publisher {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("Publisher")
+			.field("state", &self.state)
+			.field("info", &self.info)
+			.finish()
+	}
+}
+
+/// Subscribe to a broadcast by requesting tracks.
+///
+/// This can be cloned to create handles.
+#[derive(Clone)]
+pub struct Subscriber {
+	state: Watch<State>,
+	info: Arc<Info>,
+	_dropped: Arc<Dropped>,
+}
+
+impl Subscriber {
+	fn new(state: Watch<State>, info: Arc<Info>) -> Self {
+		let _dropped = Arc::new(Dropped::new(state.clone()));
+		Self { state, info, _dropped }
+	}
+
+	/// Get a track from the broadcast by name.
+	/// If the track does not exist, it will be created and potentially fufilled by the publisher (via Unknown).
+	/// Otherwise, it will return [CacheError::NotFound].
+	pub fn get_track(&self, name: &str) -> Result<track::Subscriber, CacheError> {
+		let state = self.state.lock();
+		if let Some(track) = state.get(name)? {
+			return Ok(track);
+		}
+
+		// Request a new track if it does not exist.
+		state.into_mut().request(name)
+	}
+
+	/// Check if the broadcast is closed, either because the publisher was dropped or called [Publisher::close].
+	pub fn is_closed(&self) -> Option<CacheError> {
+		self.state.lock().closed.as_ref().err().cloned()
+	}
+
+	/// Wait until if the broadcast is closed, either because the publisher was dropped or called [Publisher::close].
+	pub async fn closed(&self) -> CacheError {
+		loop {
+			let notify = {
+				let state = self.state.lock();
+				if let Some(err) = state.closed.as_ref().err() {
+					return err.clone();
+				}
+
+				state.changed()
+			};
+
+			notify.await;
+		}
+	}
+}
+
+impl Deref for Subscriber {
+	type Target = Info;
+
+	fn deref(&self) -> &Self::Target {
+		&self.info
+	}
+}
+
+impl fmt::Debug for Subscriber {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("Subscriber")
+			.field("state", &self.state)
+			.field("info", &self.info)
+			.finish()
+	}
+}
+
+// A handle that closes the broadcast when dropped:
+// - when all Subscribers are dropped or
+// - when Publisher and Unknown are dropped.
+struct Dropped {
+	state: Watch<State>,
+}
+
+impl Dropped {
+	fn new(state: Watch<State>) -> Self {
+		Self { state }
+	}
+}
+
+impl Drop for Dropped {
+	fn drop(&mut self) {
+		self.state.lock_mut().close(CacheError::Closed).ok();
+	}
+}

moq-transport/src/cache/error.rs

@@ -0,0 +1,51 @@
+use thiserror::Error;
+
+use crate::MoqError;
+
+#[derive(Clone, Debug, Error)]
+pub enum CacheError {
+	/// A clean termination, represented as error code 0.
+	/// This error is automatically used when publishers or subscribers are dropped without calling close.
+	#[error("closed")]
+	Closed,
+
+	/// An ANNOUNCE_RESET or SUBSCRIBE_RESET was sent by the publisher.
+	#[error("reset code={0:?}")]
+	Reset(u32),
+
+	/// An ANNOUNCE_STOP or SUBSCRIBE_STOP was sent by the subscriber.
+	#[error("stop")]
+	Stop,
+
+	/// The requested resource was not found.
+	#[error("not found")]
+	NotFound,
+
+	/// A resource already exists with that ID.
+	#[error("duplicate")]
+	Duplicate,
+}
+
+impl MoqError for CacheError {
+	/// An integer code that is sent over the wire.
+	fn code(&self) -> u32 {
+		match self {
+			Self::Closed => 0,
+			Self::Reset(code) => *code,
+			Self::Stop => 206,
+			Self::NotFound => 404,
+			Self::Duplicate => 409,
+		}
+	}
+
+	/// A reason that is sent over the wire.
+	fn reason(&self) -> String {
+		match self {
+			Self::Closed => "closed".to_owned(),
+			Self::Reset(code) => format!("reset code: {}", code),
+			Self::Stop => "stop".to_owned(),
+			Self::NotFound => "not found".to_owned(),
+			Self::Duplicate => "duplicate".to_owned(),
+		}
+	}
+}

moq-transport/src/cache/fragment.rs

@@ -0,0 +1,216 @@
+//! A fragment is a stream of bytes with a header, split into a [Publisher] and [Subscriber] handle.
+//!
+//! A [Publisher] writes an ordered stream of bytes in chunks.
+//! There's no framing, so these chunks can be of any size or position, and won't be maintained over the network.
+//!
+//! A [Subscriber] reads an ordered stream of bytes in chunks.
+//! These chunks are returned directly from the QUIC connection, so they may be of any size or position.
+//! You can clone the [Subscriber] and each will read a copy of of all future chunks. (fanout)
+//!
+//! The fragment is closed with [CacheError::Closed] when all publishers or subscribers are dropped.
+use core::fmt;
+use std::{ops::Deref, sync::Arc};
+
+use crate::VarInt;
+use bytes::Bytes;
+
+use super::{CacheError, Watch};
+
+/// Create a new segment with the given info.
+pub fn new(info: Info) -> (Publisher, Subscriber) {
+	let state = Watch::new(State::default());
+	let info = Arc::new(info);
+
+	let publisher = Publisher::new(state.clone(), info.clone());
+	let subscriber = Subscriber::new(state, info);
+
+	(publisher, subscriber)
+}
+
+/// Static information about the segment.
+#[derive(Debug)]
+pub struct Info {
+	// The sequence number of the fragment within the segment.
+	// NOTE: These may be received out of order or with gaps.
+	pub sequence: VarInt,
+
+	// The size of the fragment, optionally None if this is the last fragment in a segment.
+	// TODO enforce this size.
+	pub size: Option<VarInt>,
+}
+
+struct State {
+	// The data that has been received thus far.
+	chunks: Vec<Bytes>,
+
+	// Set when the publisher is dropped.
+	closed: Result<(), CacheError>,
+}
+
+impl State {
+	pub fn close(&mut self, err: CacheError) -> Result<(), CacheError> {
+		self.closed.clone()?;
+		self.closed = Err(err);
+		Ok(())
+	}
+
+	pub fn bytes(&self) -> usize {
+		self.chunks.iter().map(|f| f.len()).sum::<usize>()
+	}
+}
+
+impl Default for State {
+	fn default() -> Self {
+		Self {
+			chunks: Vec::new(),
+			closed: Ok(()),
+		}
+	}
+}
+
+impl fmt::Debug for State {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		// We don't want to print out the contents, so summarize.
+		f.debug_struct("State")
+			.field("chunks", &self.chunks.len().to_string())
+			.field("bytes", &self.bytes().to_string())
+			.field("closed", &self.closed)
+			.finish()
+	}
+}
+
+/// Used to write data to a segment and notify subscribers.
+pub struct Publisher {
+	// Mutable segment state.
+	state: Watch<State>,
+
+	// Immutable segment state.
+	info: Arc<Info>,
+
+	// Closes the segment when all Publishers are dropped.
+	_dropped: Arc<Dropped>,
+}
+
+impl Publisher {
+	fn new(state: Watch<State>, info: Arc<Info>) -> Self {
+		let _dropped = Arc::new(Dropped::new(state.clone()));
+		Self { state, info, _dropped }
+	}
+
+	/// Write a new chunk of bytes.
+	pub fn write_chunk(&mut self, chunk: Bytes) -> Result<(), CacheError> {
+		let mut state = self.state.lock_mut();
+		state.closed.clone()?;
+		state.chunks.push(chunk);
+		Ok(())
+	}
+
+	/// Close the segment with an error.
+	pub fn close(self, err: CacheError) -> Result<(), CacheError> {
+		self.state.lock_mut().close(err)
+	}
+}
+
+impl Deref for Publisher {
+	type Target = Info;
+
+	fn deref(&self) -> &Self::Target {
+		&self.info
+	}
+}
+
+impl fmt::Debug for Publisher {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("Publisher")
+			.field("state", &self.state)
+			.field("info", &self.info)
+			.finish()
+	}
+}
+
+/// Notified when a segment has new data available.
+#[derive(Clone)]
+pub struct Subscriber {
+	// Modify the segment state.
+	state: Watch<State>,
+
+	// Immutable segment state.
+	info: Arc<Info>,
+
+	// The number of chunks that we've read.
+	// NOTE: Cloned subscribers inherit this index, but then run in parallel.
+	index: usize,
+
+	// Dropped when all Subscribers are dropped.
+	_dropped: Arc<Dropped>,
+}
+
+impl Subscriber {
+	fn new(state: Watch<State>, info: Arc<Info>) -> Self {
+		let _dropped = Arc::new(Dropped::new(state.clone()));
+
+		Self {
+			state,
+			info,
+			index: 0,
+			_dropped,
+		}
+	}
+
+	/// Block until the next chunk of bytes is available.
+	pub async fn read_chunk(&mut self) -> Result<Option<Bytes>, CacheError> {
+		loop {
+			let notify = {
+				let state = self.state.lock();
+				if self.index < state.chunks.len() {
+					let chunk = state.chunks[self.index].clone();
+					self.index += 1;
+					return Ok(Some(chunk));
+				}
+
+				match &state.closed {
+					Err(CacheError::Closed) => return Ok(None),
+					Err(err) => return Err(err.clone()),
+					Ok(()) => state.changed(),
+				}
+			};
+
+			notify.await; // Try again when the state changes
+		}
+	}
+}
+
+impl Deref for Subscriber {
+	type Target = Info;
+
+	fn deref(&self) -> &Self::Target {
+		&self.info
+	}
+}
+
+impl fmt::Debug for Subscriber {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("Subscriber")
+			.field("state", &self.state)
+			.field("info", &self.info)
+			.field("index", &self.index)
+			.finish()
+	}
+}
+
+struct Dropped {
+	// Modify the segment state.
+	state: Watch<State>,
+}
+
+impl Dropped {
+	fn new(state: Watch<State>) -> Self {
+		Self { state }
+	}
+}
+
+impl Drop for Dropped {
+	fn drop(&mut self) {
+		self.state.lock_mut().close(CacheError::Closed).ok();
+	}
+}

moq-transport/src/cache/mod.rs

@@ -0,0 +1,21 @@
+//! Allows a publisher to push updates, automatically caching and fanning it out to any subscribers.
+//!
+//! The hierarchy is: [broadcast] -> [track] -> [segment] -> [fragment] -> [Bytes](bytes::Bytes)
+//!
+//! The naming scheme doesn't match the spec because it's more strict, and bikeshedding of course:
+//!
+//! - [broadcast] is kinda like "track namespace"
+//! - [track] is "track"
+//! - [segment] is "group" but MUST use a single stream.
+//! - [fragment] is "object" but MUST have the same properties as the segment.
+
+pub mod broadcast;
+mod error;
+pub mod fragment;
+pub mod segment;
+pub mod track;
+
+pub(crate) mod watch;
+pub(crate) use watch::*;
+
+pub use error::*;

moq-transport/src/cache/segment.rs

@@ -0,0 +1,216 @@
+//! A segment is a stream of fragments with a header, split into a [Publisher] and [Subscriber] handle.
+//!
+//! A [Publisher] writes an ordered stream of fragments.
+//! Each fragment can have a sequence number, allowing the subscriber to detect gaps fragments.
+//!
+//! A [Subscriber] reads an ordered stream of fragments.
+//! The subscriber can be cloned, in which case each subscriber receives a copy of each fragment. (fanout)
+//!
+//! The segment is closed with [CacheError::Closed] when all publishers or subscribers are dropped.
+use core::fmt;
+use std::{ops::Deref, sync::Arc, time};
+
+use crate::VarInt;
+
+use super::{fragment, CacheError, Watch};
+
+/// Create a new segment with the given info.
+pub fn new(info: Info) -> (Publisher, Subscriber) {
+	let state = Watch::new(State::default());
+	let info = Arc::new(info);
+
+	let publisher = Publisher::new(state.clone(), info.clone());
+	let subscriber = Subscriber::new(state, info);
+
+	(publisher, subscriber)
+}
+
+/// Static information about the segment.
+#[derive(Debug)]
+pub struct Info {
+	// The sequence number of the segment within the track.
+	// NOTE: These may be received out of order or with gaps.
+	pub sequence: VarInt,
+
+	// The priority of the segment within the BROADCAST.
+	pub priority: u32,
+
+	// Cache the segment for at most this long.
+	pub expires: Option<time::Duration>,
+}
+
+struct State {
+	// The data that has been received thus far.
+	fragments: Vec<fragment::Subscriber>,
+
+	// Set when the publisher is dropped.
+	closed: Result<(), CacheError>,
+}
+
+impl State {
+	pub fn close(&mut self, err: CacheError) -> Result<(), CacheError> {
+		self.closed.clone()?;
+		self.closed = Err(err);
+		Ok(())
+	}
+}
+
+impl Default for State {
+	fn default() -> Self {
+		Self {
+			fragments: Vec::new(),
+			closed: Ok(()),
+		}
+	}
+}
+
+impl fmt::Debug for State {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("State")
+			.field("fragments", &self.fragments)
+			.field("closed", &self.closed)
+			.finish()
+	}
+}
+
+/// Used to write data to a segment and notify subscribers.
+pub struct Publisher {
+	// Mutable segment state.
+	state: Watch<State>,
+
+	// Immutable segment state.
+	info: Arc<Info>,
+
+	// Closes the segment when all Publishers are dropped.
+	_dropped: Arc<Dropped>,
+}
+
+impl Publisher {
+	fn new(state: Watch<State>, info: Arc<Info>) -> Self {
+		let _dropped = Arc::new(Dropped::new(state.clone()));
+		Self { state, info, _dropped }
+	}
+
+	/// Write a fragment
+	pub fn push_fragment(&mut self, fragment: fragment::Subscriber) -> Result<(), CacheError> {
+		let mut state = self.state.lock_mut();
+		state.closed.clone()?;
+		state.fragments.push(fragment);
+		Ok(())
+	}
+
+	pub fn create_fragment(&mut self, fragment: fragment::Info) -> Result<fragment::Publisher, CacheError> {
+		let (publisher, subscriber) = fragment::new(fragment);
+		self.push_fragment(subscriber)?;
+		Ok(publisher)
+	}
+
+	/// Close the segment with an error.
+	pub fn close(self, err: CacheError) -> Result<(), CacheError> {
+		self.state.lock_mut().close(err)
+	}
+}
+
+impl Deref for Publisher {
+	type Target = Info;
+
+	fn deref(&self) -> &Self::Target {
+		&self.info
+	}
+}
+
+impl fmt::Debug for Publisher {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("Publisher")
+			.field("state", &self.state)
+			.field("info", &self.info)
+			.finish()
+	}
+}
+
+/// Notified when a segment has new data available.
+#[derive(Clone)]
+pub struct Subscriber {
+	// Modify the segment state.
+	state: Watch<State>,
+
+	// Immutable segment state.
+	info: Arc<Info>,
+
+	// The number of chunks that we've read.
+	// NOTE: Cloned subscribers inherit this index, but then run in parallel.
+	index: usize,
+
+	// Dropped when all Subscribers are dropped.
+	_dropped: Arc<Dropped>,
+}
+
+impl Subscriber {
+	fn new(state: Watch<State>, info: Arc<Info>) -> Self {
+		let _dropped = Arc::new(Dropped::new(state.clone()));
+
+		Self {
+			state,
+			info,
+			index: 0,
+			_dropped,
+		}
+	}
+
+	/// Block until the next chunk of bytes is available.
+	pub async fn next_fragment(&mut self) -> Result<Option<fragment::Subscriber>, CacheError> {
+		loop {
+			let notify = {
+				let state = self.state.lock();
+				if self.index < state.fragments.len() {
+					let fragment = state.fragments[self.index].clone();
+					self.index += 1;
+					return Ok(Some(fragment));
+				}
+
+				match &state.closed {
+					Err(CacheError::Closed) => return Ok(None),
+					Err(err) => return Err(err.clone()),
+					Ok(()) => state.changed(),
+				}
+			};
+
+			notify.await; // Try again when the state changes
+		}
+	}
+}
+
+impl Deref for Subscriber {
+	type Target = Info;
+
+	fn deref(&self) -> &Self::Target {
+		&self.info
+	}
+}
+
+impl fmt::Debug for Subscriber {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("Subscriber")
+			.field("state", &self.state)
+			.field("info", &self.info)
+			.field("index", &self.index)
+			.finish()
+	}
+}
+
+struct Dropped {
+	// Modify the segment state.
+	state: Watch<State>,
+}
+
+impl Dropped {
+	fn new(state: Watch<State>) -> Self {
+		Self { state }
+	}
+}
+
+impl Drop for Dropped {
+	fn drop(&mut self) {
+		self.state.lock_mut().close(CacheError::Closed).ok();
+	}
+}

moq-transport/src/cache/track.rs

@@ -0,0 +1,337 @@
+//! A track is a collection of semi-reliable and semi-ordered segments, split into a [Publisher] and [Subscriber] handle.
+//!
+//! A [Publisher] creates segments with a sequence number and priority.
+//! The sequest number is used to determine the order of segments, while the priority is used to determine which segment to transmit first.
+//! This may seem counter-intuitive, but is designed for live streaming where the newest segments may be higher priority.
+//! A cloned [Publisher] can be used to create segments in parallel, but will error if a duplicate sequence number is used.
+//!
+//! A [Subscriber] may not receive all segments in order or at all.
+//! These segments are meant to be transmitted over congested networks and the key to MoQ Tranport is to not block on them.
+//! Segments will be cached for a potentially limited duration added to the unreliable nature.
+//! A cloned [Subscriber] will receive a copy of all new segment going forward (fanout).
+//!
+//! The track is closed with [CacheError::Closed] when all publishers or subscribers are dropped.
+
+use std::{collections::BinaryHeap, fmt, ops::Deref, sync::Arc, time};
+
+use indexmap::IndexMap;
+
+use super::{segment, CacheError, Watch};
+use crate::VarInt;
+
+/// Create a track with the given name.
+pub fn new(name: &str) -> (Publisher, Subscriber) {
+	let state = Watch::new(State::default());
+	let info = Arc::new(Info { name: name.to_string() });
+
+	let publisher = Publisher::new(state.clone(), info.clone());
+	let subscriber = Subscriber::new(state, info);
+
+	(publisher, subscriber)
+}
+
+/// Static information about a track.
+#[derive(Debug)]
+pub struct Info {
+	pub name: String,
+}
+
+struct State {
+	// Store segments in received order so subscribers can detect changes.
+	// The key is the segment sequence, which could have gaps.
+	// A None value means the segment has expired.
+	lookup: IndexMap<VarInt, Option<segment::Subscriber>>,
+
+	// Store when segments will expire in a priority queue.
+	expires: BinaryHeap<SegmentExpiration>,
+
+	// The number of None entries removed from the start of the lookup.
+	pruned: usize,
+
+	// Set when the publisher is closed/dropped, or all subscribers are dropped.
+	closed: Result<(), CacheError>,
+}
+
+impl State {
+	pub fn close(&mut self, err: CacheError) -> Result<(), CacheError> {
+		self.closed.clone()?;
+		self.closed = Err(err);
+		Ok(())
+	}
+
+	pub fn insert(&mut self, segment: segment::Subscriber) -> Result<(), CacheError> {
+		self.closed.clone()?;
+
+		let entry = match self.lookup.entry(segment.sequence) {
+			indexmap::map::Entry::Occupied(_entry) => return Err(CacheError::Duplicate),
+			indexmap::map::Entry::Vacant(entry) => entry,
+		};
+
+		if let Some(expires) = segment.expires {
+			self.expires.push(SegmentExpiration {
+				sequence: segment.sequence,
+				expires: time::Instant::now() + expires,
+			});
+		}
+
+		entry.insert(Some(segment));
+
+		// Expire any existing segments on insert.
+		// This means if you don't insert then you won't expire... but it's probably fine since the cache won't grow.
+		// TODO Use a timer to expire segments at the correct time instead
+		self.expire();
+
+		Ok(())
+	}
+
+	// Try expiring any segments
+	pub fn expire(&mut self) {
+		let now = time::Instant::now();
+		while let Some(segment) = self.expires.peek() {
+			if segment.expires > now {
+				break;
+			}
+
+			// Update the entry to None while preserving the index.
+			match self.lookup.entry(segment.sequence) {
+				indexmap::map::Entry::Occupied(mut entry) => entry.insert(None),
+				indexmap::map::Entry::Vacant(_) => panic!("expired segment not found"),
+			};
+
+			self.expires.pop();
+		}
+
+		// Remove None entries from the start of the lookup.
+		while let Some((_, None)) = self.lookup.get_index(0) {
+			self.lookup.shift_remove_index(0);
+			self.pruned += 1;
+		}
+	}
+}
+
+impl Default for State {
+	fn default() -> Self {
+		Self {
+			lookup: Default::default(),
+			expires: Default::default(),
+			pruned: 0,
+			closed: Ok(()),
+		}
+	}
+}
+
+impl fmt::Debug for State {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("State")
+			.field("lookup", &self.lookup)
+			.field("pruned", &self.pruned)
+			.field("closed", &self.closed)
+			.finish()
+	}
+}
+
+/// Creates new segments for a track.
+pub struct Publisher {
+	state: Watch<State>,
+	info: Arc<Info>,
+	_dropped: Arc<Dropped>,
+}
+
+impl Publisher {
+	fn new(state: Watch<State>, info: Arc<Info>) -> Self {
+		let _dropped = Arc::new(Dropped::new(state.clone()));
+		Self { state, info, _dropped }
+	}
+
+	/// Insert a new segment.
+	pub fn insert_segment(&mut self, segment: segment::Subscriber) -> Result<(), CacheError> {
+		self.state.lock_mut().insert(segment)
+	}
+
+	/// Create an insert a segment with the given info.
+	pub fn create_segment(&mut self, info: segment::Info) -> Result<segment::Publisher, CacheError> {
+		let (publisher, subscriber) = segment::new(info);
+		self.insert_segment(subscriber)?;
+		Ok(publisher)
+	}
+
+	/// Close the segment with an error.
+	pub fn close(self, err: CacheError) -> Result<(), CacheError> {
+		self.state.lock_mut().close(err)
+	}
+}
+
+impl Deref for Publisher {
+	type Target = Info;
+
+	fn deref(&self) -> &Self::Target {
+		&self.info
+	}
+}
+
+impl fmt::Debug for Publisher {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("Publisher")
+			.field("state", &self.state)
+			.field("info", &self.info)
+			.finish()
+	}
+}
+
+/// Receives new segments for a track.
+#[derive(Clone)]
+pub struct Subscriber {
+	state: Watch<State>,
+	info: Arc<Info>,
+
+	// The index of the next segment to return.
+	index: usize,
+
+	// If there are multiple segments to return, we put them in here to return them in priority order.
+	pending: BinaryHeap<SegmentPriority>,
+
+	// Dropped when all subscribers are dropped.
+	_dropped: Arc<Dropped>,
+}
+
+impl Subscriber {
+	fn new(state: Watch<State>, info: Arc<Info>) -> Self {
+		let _dropped = Arc::new(Dropped::new(state.clone()));
+		Self {
+			state,
+			info,
+			index: 0,
+			pending: Default::default(),
+			_dropped,
+		}
+	}
+
+	/// Block until the next segment arrives
+	pub async fn next_segment(&mut self) -> Result<Option<segment::Subscriber>, CacheError> {
+		loop {
+			let notify = {
+				let state = self.state.lock();
+
+				// Get our adjusted index, which could be negative if we've removed more broadcasts than read.
+				let mut index = self.index.saturating_sub(state.pruned);
+
+				// Push all new segments into a priority queue.
+				while index < state.lookup.len() {
+					let (_, segment) = state.lookup.get_index(index).unwrap();
+
+					// Skip None values (expired segments).
+					// TODO These might actually be expired, so we should check the expiration time.
+					if let Some(segment) = segment {
+						self.pending.push(SegmentPriority(segment.clone()));
+					}
+
+					index += 1;
+				}
+
+				self.index = state.pruned + index;
+
+				// Return the higher priority segment.
+				if let Some(segment) = self.pending.pop() {
+					return Ok(Some(segment.0));
+				}
+
+				// Otherwise check if we need to return an error.
+				match &state.closed {
+					Err(CacheError::Closed) => return Ok(None),
+					Err(err) => return Err(err.clone()),
+					Ok(()) => state.changed(),
+				}
+			};
+
+			notify.await
+		}
+	}
+}
+
+impl Deref for Subscriber {
+	type Target = Info;
+
+	fn deref(&self) -> &Self::Target {
+		&self.info
+	}
+}
+
+impl fmt::Debug for Subscriber {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("Subscriber")
+			.field("state", &self.state)
+			.field("info", &self.info)
+			.field("index", &self.index)
+			.finish()
+	}
+}
+
+// Closes the track on Drop.
+struct Dropped {
+	state: Watch<State>,
+}
+
+impl Dropped {
+	fn new(state: Watch<State>) -> Self {
+		Self { state }
+	}
+}
+
+impl Drop for Dropped {
+	fn drop(&mut self) {
+		self.state.lock_mut().close(CacheError::Closed).ok();
+	}
+}
+
+// Used to order segments by expiration time.
+struct SegmentExpiration {
+	sequence: VarInt,
+	expires: time::Instant,
+}
+
+impl Ord for SegmentExpiration {
+	fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+		// Reverse order so the earliest expiration is at the top of the heap.
+		other.expires.cmp(&self.expires)
+	}
+}
+
+impl PartialOrd for SegmentExpiration {
+	fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+		Some(self.cmp(other))
+	}
+}
+
+impl PartialEq for SegmentExpiration {
+	fn eq(&self, other: &Self) -> bool {
+		self.expires == other.expires
+	}
+}
+
+impl Eq for SegmentExpiration {}
+
+// Used to order segments by priority
+#[derive(Clone)]
+struct SegmentPriority(pub segment::Subscriber);
+
+impl Ord for SegmentPriority {
+	fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+		// Reverse order so the highest priority is at the top of the heap.
+		// TODO I let CodePilot generate this code so yolo
+		other.0.priority.cmp(&self.0.priority)
+	}
+}
+
+impl PartialOrd for SegmentPriority {
+	fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+		Some(self.cmp(other))
+	}
+}
+
+impl PartialEq for SegmentPriority {
+	fn eq(&self, other: &Self) -> bool {
+		self.0.priority == other.0.priority
+	}
+}
+
+impl Eq for SegmentPriority {}

moq-transport/src/cache/watch.rs

@@ -0,0 +1,180 @@
+use std::{
+	fmt,
+	future::Future,
+	ops::{Deref, DerefMut},
+	pin::Pin,
+	sync::{Arc, Mutex, MutexGuard},
+	task,
+};
+
+struct State<T> {
+	value: T,
+	wakers: Vec<task::Waker>,
+	epoch: usize,
+}
+
+impl<T> State<T> {
+	pub fn new(value: T) -> Self {
+		Self {
+			value,
+			wakers: Vec::new(),
+			epoch: 0,
+		}
+	}
+
+	pub fn register(&mut self, waker: &task::Waker) {
+		self.wakers.retain(|existing| !existing.will_wake(waker));
+		self.wakers.push(waker.clone());
+	}
+
+	pub fn notify(&mut self) {
+		self.epoch += 1;
+		for waker in self.wakers.drain(..) {
+			waker.wake();
+		}
+	}
+}
+
+impl<T: Default> Default for State<T> {
+	fn default() -> Self {
+		Self::new(T::default())
+	}
+}
+
+impl<T: fmt::Debug> fmt::Debug for State<T> {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		self.value.fmt(f)
+	}
+}
+
+pub struct Watch<T> {
+	state: Arc<Mutex<State<T>>>,
+}
+
+impl<T> Watch<T> {
+	pub fn new(initial: T) -> Self {
+		let state = Arc::new(Mutex::new(State::new(initial)));
+		Self { state }
+	}
+
+	pub fn lock(&self) -> WatchRef<T> {
+		WatchRef {
+			state: self.state.clone(),
+			lock: self.state.lock().unwrap(),
+		}
+	}
+
+	pub fn lock_mut(&self) -> WatchMut<T> {
+		WatchMut {
+			lock: self.state.lock().unwrap(),
+		}
+	}
+}
+
+impl<T> Clone for Watch<T> {
+	fn clone(&self) -> Self {
+		Self {
+			state: self.state.clone(),
+		}
+	}
+}
+
+impl<T: Default> Default for Watch<T> {
+	fn default() -> Self {
+		Self::new(T::default())
+	}
+}
+
+impl<T: fmt::Debug> fmt::Debug for Watch<T> {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		match self.state.try_lock() {
+			Ok(lock) => lock.value.fmt(f),
+			Err(_) => write!(f, "<locked>"),
+		}
+	}
+}
+
+pub struct WatchRef<'a, T> {
+	state: Arc<Mutex<State<T>>>,
+	lock: MutexGuard<'a, State<T>>,
+}
+
+impl<'a, T> WatchRef<'a, T> {
+	// Release the lock and wait for a notification when next updated.
+	pub fn changed(self) -> WatchChanged<T> {
+		WatchChanged {
+			state: self.state,
+			epoch: self.lock.epoch,
+		}
+	}
+
+	// Upgrade to a mutable references that automatically calls notify on drop.
+	pub fn into_mut(self) -> WatchMut<'a, T> {
+		WatchMut { lock: self.lock }
+	}
+}
+
+impl<'a, T> Deref for WatchRef<'a, T> {
+	type Target = T;
+
+	fn deref(&self) -> &Self::Target {
+		&self.lock.value
+	}
+}
+
+impl<'a, T: fmt::Debug> fmt::Debug for WatchRef<'a, T> {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		self.lock.fmt(f)
+	}
+}
+
+pub struct WatchMut<'a, T> {
+	lock: MutexGuard<'a, State<T>>,
+}
+
+impl<'a, T> Deref for WatchMut<'a, T> {
+	type Target = T;
+
+	fn deref(&self) -> &Self::Target {
+		&self.lock.value
+	}
+}
+
+impl<'a, T> DerefMut for WatchMut<'a, T> {
+	fn deref_mut(&mut self) -> &mut Self::Target {
+		&mut self.lock.value
+	}
+}
+
+impl<'a, T> Drop for WatchMut<'a, T> {
+	fn drop(&mut self) {
+		self.lock.notify();
+	}
+}
+
+impl<'a, T: fmt::Debug> fmt::Debug for WatchMut<'a, T> {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		self.lock.fmt(f)
+	}
+}
+
+pub struct WatchChanged<T> {
+	state: Arc<Mutex<State<T>>>,
+	epoch: usize,
+}
+
+impl<T> Future for WatchChanged<T> {
+	type Output = ();
+
+	fn poll(self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> task::Poll<Self::Output> {
+		// TODO is there an API we can make that doesn't drop this lock?
+		let mut state = self.state.lock().unwrap();
+
+		if state.epoch > self.epoch {
+			task::Poll::Ready(())
+		} else {
+			state.register(cx.waker());
+			task::Poll::Pending
+		}
+	}
+}

moq-transport/src/coding/decode.rs

@@ -1,9 +1,21 @@
-use super::VarInt;
+use super::{BoundsExceeded, VarInt};
-use bytes::{Buf, Bytes};
+use std::{io, str};
-use std::str;
 
 use thiserror::Error;
 
+// I'm too lazy to add these trait bounds to every message type.
+// TODO Use trait aliases when they're stable, or add these bounds to every method.
+pub trait AsyncRead: tokio::io::AsyncRead + Unpin + Send {}
+impl AsyncRead for webtransport_quinn::RecvStream {}
+impl<T> AsyncRead for tokio::io::Take<&mut T> where T: AsyncRead {}
+impl<T: AsRef<[u8]> + Unpin + Send> AsyncRead for io::Cursor<T> {}
+
+#[async_trait::async_trait]
+pub trait Decode: Sized {
+	async fn decode<R: AsyncRead>(r: &mut R) -> Result<Self, DecodeError>;
+}
+
+/// A decode error.
 #[derive(Error, Debug)]
 pub enum DecodeError {
 	#[error("unexpected end of buffer")]
@@ -12,65 +24,32 @@ pub enum DecodeError {
 	#[error("invalid string")]
 	InvalidString(#[from] str::Utf8Error),
 
-	#[error("invalid type: {0:?}")]
+	#[error("invalid message: {0:?}")]
-	InvalidType(VarInt),
+	InvalidMessage(VarInt),
 
-	#[error("unknown error")]
+	#[error("invalid role: {0:?}")]
-	Unknown,
+	InvalidRole(VarInt),
-}
 
-pub trait Decode: Sized {
+	#[error("invalid subscribe location")]
-	// Decodes a message, returning UnexpectedEnd if there's not enough bytes in the buffer.
+	InvalidSubscribeLocation,
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError>;
-}
 
-impl Decode for Bytes {
+	#[error("varint bounds exceeded")]
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+	BoundsExceeded(#[from] BoundsExceeded),
-		let size = VarInt::decode(r)?.into_inner() as usize;
-		if r.remaining() < size {
-			return Err(DecodeError::UnexpectedEnd);
-		}
 
-		let buf = r.copy_to_bytes(size);
+	// TODO move these to ParamError
-		Ok(buf)
+	#[error("duplicate parameter")]
-	}
+	DupliateParameter,
-}
 
-impl Decode for Vec<u8> {
+	#[error("missing parameter")]
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+	MissingParameter,
-		Bytes::decode(r).map(|b| b.to_vec())
-	}
-}
 
-impl Decode for String {
+	#[error("invalid parameter")]
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+	InvalidParameter,
-		let data = Vec::decode(r)?;
-		let s = str::from_utf8(&data)?.to_string();
-		Ok(s)
-	}
-}
 
-impl Decode for u8 {
+	#[error("io error: {0}")]
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+	IoError(#[from] std::io::Error),
-		if r.remaining() < 1 {
-			return Err(DecodeError::UnexpectedEnd);
-		}
 
-		Ok(r.get_u8())
+	// Used to signal that the stream has ended.
+	#[error("no more messages")]
+	Final,
 }
-}
-
-/*
-impl<const N: usize> Decode for [u8; N] {
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
-		if r.remaining() < N {
-			return Err(DecodeError::UnexpectedEnd);
-		}
-
-		let mut buf = [0; N];
-		r.copy_to_slice(&mut buf);
-
-		Ok(buf)
-	}
-}
-*/

moq-transport/src/coding/duration.rs

@@ -1,20 +0,0 @@
-use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
-
-use bytes::{Buf, BufMut};
-
-use std::time::Duration;
-
-impl Encode for Duration {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
-		let ms = self.as_millis();
-		let ms = VarInt::try_from(ms)?;
-		ms.encode(w)
-	}
-}
-
-impl Decode for Duration {
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
-		let ms = VarInt::decode(r)?;
-		Ok(Self::from_millis(ms.into()))
-	}
-}

moq-transport/src/coding/encode.rs

@@ -1,92 +1,27 @@
-use super::{BoundsExceeded, VarInt};
+use super::BoundsExceeded;
-use bytes::{BufMut, Bytes};
 
 use thiserror::Error;
 
+// I'm too lazy to add these trait bounds to every message type.
+// TODO Use trait aliases when they're stable, or add these bounds to every method.
+pub trait AsyncWrite: tokio::io::AsyncWrite + Unpin + Send {}
+impl AsyncWrite for webtransport_quinn::SendStream {}
+impl AsyncWrite for Vec<u8> {}
+
+#[async_trait::async_trait]
+pub trait Encode: Sized {
+	async fn encode<W: AsyncWrite>(&self, w: &mut W) -> Result<(), EncodeError>;
+}
+
+/// An encode error.
 #[derive(Error, Debug)]
 pub enum EncodeError {
-	#[error("unexpected end of buffer")]
-	UnexpectedEnd,
-
 	#[error("varint too large")]
 	BoundsExceeded(#[from] BoundsExceeded),
-}
 
-pub trait Encode: Sized {
+	#[error("invalid value")]
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError>;
+	InvalidValue,
-}
 
-impl Encode for Bytes {
+	#[error("i/o error: {0}")]
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
+	IoError(#[from] std::io::Error),
-		self.as_ref().encode(w)
-	}
-}
-
-impl Encode for Vec<u8> {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
-		self.as_slice().encode(w)
-	}
-}
-
-impl Encode for &[u8] {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
-		let size = VarInt::try_from(self.len())?;
-		size.encode(w)?;
-
-		if w.remaining_mut() < self.len() {
-			return Err(EncodeError::UnexpectedEnd);
-		}
-		w.put_slice(self);
-
-		Ok(())
-	}
-}
-
-impl Encode for String {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
-		self.as_bytes().encode(w)
-	}
-}
-
-impl Encode for u8 {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
-		if w.remaining_mut() < 1 {
-			return Err(EncodeError::UnexpectedEnd);
-		}
-
-		w.put_u8(*self);
-		Ok(())
-	}
-}
-
-impl Encode for u16 {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
-		if w.remaining_mut() < 2 {
-			return Err(EncodeError::UnexpectedEnd);
-		}
-
-		w.put_u16(*self);
-		Ok(())
-	}
-}
-
-impl Encode for u32 {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
-		if w.remaining_mut() < 4 {
-			return Err(EncodeError::UnexpectedEnd);
-		}
-
-		w.put_u32(*self);
-		Ok(())
-	}
-}
-impl Encode for u64 {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
-		if w.remaining_mut() < 8 {
-			return Err(EncodeError::UnexpectedEnd);
-		}
-
-		w.put_u64(*self);
-		Ok(())
-	}
 }

moq-transport/src/coding/mod.rs

@@ -1,9 +1,11 @@
 mod decode;
-mod duration;
 mod encode;
+mod params;
+mod string;
 mod varint;
 
 pub use decode::*;
-pub use duration::*;
 pub use encode::*;
+pub use params::*;
+pub use string::*;
 pub use varint::*;

moq-transport/src/coding/params.rs

@@ -0,0 +1,85 @@
+use std::io::Cursor;
+use std::{cmp::max, collections::HashMap};
+
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+
+use crate::coding::{AsyncRead, AsyncWrite, Decode, Encode};
+
+use crate::{
+	coding::{DecodeError, EncodeError},
+	VarInt,
+};
+
+#[derive(Default, Debug, Clone)]
+pub struct Params(pub HashMap<VarInt, Vec<u8>>);
+
+#[async_trait::async_trait]
+impl Decode for Params {
+	async fn decode<R: AsyncRead>(mut r: &mut R) -> Result<Self, DecodeError> {
+		let mut params = HashMap::new();
+
+		// I hate this shit so much; let me encode my role and get on with my life.
+		let count = VarInt::decode(r).await?;
+		for _ in 0..count.into_inner() {
+			let kind = VarInt::decode(r).await?;
+			if params.contains_key(&kind) {
+				return Err(DecodeError::DupliateParameter);
+			}
+
+			let size = VarInt::decode(r).await?;
+
+			// Don't allocate the entire requested size to avoid a possible attack
+			// Instead, we allocate up to 1024 and keep appending as we read further.
+			let mut pr = r.take(size.into_inner());
+			let mut buf = Vec::with_capacity(max(1024, pr.limit() as usize));
+			pr.read_to_end(&mut buf).await?;
+			params.insert(kind, buf);
+
+			r = pr.into_inner();
+		}
+
+		Ok(Params(params))
+	}
+}
+
+#[async_trait::async_trait]
+impl Encode for Params {
+	async fn encode<W: AsyncWrite>(&self, w: &mut W) -> Result<(), EncodeError> {
+		VarInt::try_from(self.0.len())?.encode(w).await?;
+
+		for (kind, value) in self.0.iter() {
+			kind.encode(w).await?;
+			VarInt::try_from(value.len())?.encode(w).await?;
+			w.write_all(value).await?;
+		}
+
+		Ok(())
+	}
+}
+
+impl Params {
+	pub fn new() -> Self {
+		Self::default()
+	}
+
+	pub async fn set<P: Encode>(&mut self, kind: VarInt, p: P) -> Result<(), EncodeError> {
+		let mut value = Vec::new();
+		p.encode(&mut value).await?;
+		self.0.insert(kind, value);
+
+		Ok(())
+	}
+
+	pub fn has(&self, kind: VarInt) -> bool {
+		self.0.contains_key(&kind)
+	}
+
+	pub async fn get<P: Decode>(&mut self, kind: VarInt) -> Result<Option<P>, DecodeError> {
+		if let Some(value) = self.0.remove(&kind) {
+			let mut cursor = Cursor::new(value);
+			Ok(Some(P::decode(&mut cursor).await?))
+		} else {
+			Ok(None)
+		}
+	}
+}

moq-transport/src/coding/string.rs

@@ -0,0 +1,29 @@
+use std::cmp::min;
+
+use crate::coding::{AsyncRead, AsyncWrite};
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+
+use crate::VarInt;
+
+use super::{Decode, DecodeError, Encode, EncodeError};
+
+#[async_trait::async_trait]
+impl Encode for String {
+	async fn encode<W: AsyncWrite>(&self, w: &mut W) -> Result<(), EncodeError> {
+		let size = VarInt::try_from(self.len())?;
+		size.encode(w).await?;
+		w.write_all(self.as_ref()).await?;
+		Ok(())
+	}
+}
+
+#[async_trait::async_trait]
+impl Decode for String {
+	/// Decode a string with a varint length prefix.
+	async fn decode<R: AsyncRead>(r: &mut R) -> Result<Self, DecodeError> {
+		let size = VarInt::decode(r).await?.into_inner();
+		let mut str = String::with_capacity(min(1024, size) as usize);
+		r.take(size).read_to_string(&mut str).await?;
+		Ok(str)
+	}
+}

moq-transport/src/coding/varint.rs

@@ -5,13 +5,14 @@
 use std::convert::{TryFrom, TryInto};
 use std::fmt;
 
-use crate::coding::{Decode, DecodeError, Encode, EncodeError};
+use crate::coding::{AsyncRead, AsyncWrite};
-
-use bytes::{Buf, BufMut};
 use thiserror::Error;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+
+use super::{Decode, DecodeError, Encode, EncodeError};
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Error)]
-#[error("value too large for varint encoding")]
+#[error("value out of range")]
 pub struct BoundsExceeded;
 
 /// An integer less than 2^62
@@ -23,8 +24,12 @@ pub struct BoundsExceeded;
 pub struct VarInt(u64);
 
 impl VarInt {
+	/// The largest possible value.
 	pub const MAX: Self = Self((1 << 62) - 1);
 
+	/// The smallest possible value.
+	pub const ZERO: Self = Self(0);
+
 	/// Construct a `VarInt` infallibly using the largest available type.
 	/// Larger values need to use `try_from` instead.
 	pub const fn from_u32(x: u32) -> Self {
@@ -108,6 +113,45 @@ impl TryFrom<usize> for VarInt {
 	}
 }
 
+impl TryFrom<VarInt> for u32 {
+	type Error = BoundsExceeded;
+
+	/// Succeeds iff `x` < 2^32
+	fn try_from(x: VarInt) -> Result<Self, BoundsExceeded> {
+		if x.0 <= u32::MAX.into() {
+			Ok(x.0 as u32)
+		} else {
+			Err(BoundsExceeded)
+		}
+	}
+}
+
+impl TryFrom<VarInt> for u16 {
+	type Error = BoundsExceeded;
+
+	/// Succeeds iff `x` < 2^16
+	fn try_from(x: VarInt) -> Result<Self, BoundsExceeded> {
+		if x.0 <= u16::MAX.into() {
+			Ok(x.0 as u16)
+		} else {
+			Err(BoundsExceeded)
+		}
+	}
+}
+
+impl TryFrom<VarInt> for u8 {
+	type Error = BoundsExceeded;
+
+	/// Succeeds iff `x` < 2^8
+	fn try_from(x: VarInt) -> Result<Self, BoundsExceeded> {
+		if x.0 <= u8::MAX.into() {
+			Ok(x.0 as u8)
+		} else {
+			Err(BoundsExceeded)
+		}
+	}
+}
+
 impl fmt::Debug for VarInt {
 	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 		self.0.fmt(f)
@@ -120,43 +164,36 @@ impl fmt::Display for VarInt {
 	}
 }
 
+#[async_trait::async_trait]
 impl Decode for VarInt {
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+	/// Decode a varint from the given reader.
-		let mut buf = [0; 8];
+	async fn decode<R: AsyncRead>(r: &mut R) -> Result<Self, DecodeError> {
-
+		let b = r.read_u8().await?;
-		if r.remaining() < 1 {
+		Self::decode_byte(b, r).await
-			return Err(DecodeError::UnexpectedEnd);
+	}
 }
 
-		buf[0] = r.get_u8();
+impl VarInt {
+	/// Decode a varint given the first byte, reading the rest as needed.
+	/// This is silly but useful for determining if the stream has ended.
+	pub async fn decode_byte<R: AsyncRead>(b: u8, r: &mut R) -> Result<Self, DecodeError> {
+		let tag = b >> 6;
 
-		let tag = buf[0] >> 6;
+		let mut buf = [0u8; 8];
-		buf[0] &= 0b0011_1111;
+		buf[0] = b & 0b0011_1111;
 
 		let x = match tag {
 			0b00 => u64::from(buf[0]),
 			0b01 => {
-				if r.remaining() < 1 {
+				r.read_exact(buf[1..2].as_mut()).await?;
-					return Err(DecodeError::UnexpectedEnd);
-				}
-
-				r.copy_to_slice(buf[1..2].as_mut());
 				u64::from(u16::from_be_bytes(buf[..2].try_into().unwrap()))
 			}
 			0b10 => {
-				if r.remaining() < 3 {
+				r.read_exact(buf[1..4].as_mut()).await?;
-					return Err(DecodeError::UnexpectedEnd);
-				}
-
-				r.copy_to_slice(buf[1..4].as_mut());
 				u64::from(u32::from_be_bytes(buf[..4].try_into().unwrap()))
 			}
 			0b11 => {
-				if r.remaining() < 7 {
+				r.read_exact(buf[1..8].as_mut()).await?;
-					return Err(DecodeError::UnexpectedEnd);
-				}
-
-				r.copy_to_slice(buf[1..8].as_mut());
 				u64::from_be_bytes(buf)
 			}
 			_ => unreachable!(),
@@ -166,19 +203,30 @@ impl Decode for VarInt {
 	}
 }
 
+#[async_trait::async_trait]
 impl Encode for VarInt {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
+	/// Encode a varint to the given writer.
+	async fn encode<W: AsyncWrite>(&self, w: &mut W) -> Result<(), EncodeError> {
 		let x = self.0;
 		if x < 2u64.pow(6) {
-			(x as u8).encode(w)
+			w.write_u8(x as u8).await?;
 		} else if x < 2u64.pow(14) {
-			(0b01 << 14 | x as u16).encode(w)
+			w.write_u16(0b01 << 14 | x as u16).await?;
 		} else if x < 2u64.pow(30) {
-			(0b10 << 30 | x as u32).encode(w)
+			w.write_u32(0b10 << 30 | x as u32).await?;
 		} else if x < 2u64.pow(62) {
-			(0b11 << 62 | x).encode(w)
+			w.write_u64(0b11 << 62 | x).await?;
 		} else {
 			unreachable!("malformed VarInt");
 		}
+
+		Ok(())
+	}
+}
+
+// This is a fork of quinn::VarInt.
+impl From<quinn::VarInt> for VarInt {
+	fn from(v: quinn::VarInt) -> Self {
+		Self(v.into_inner())
 	}
 }

moq-transport/src/error.rs

@@ -0,0 +1,7 @@
+pub trait MoqError {
+	/// An integer code that is sent over the wire.
+	fn code(&self) -> u32;
+
+	/// An optional reason sometimes sent over the wire.
+	fn reason(&self) -> String;
+}

moq-transport/src/lib.rs

@@ -1,9 +1,18 @@
+//! An implementation of the MoQ Transport protocol.
+//!
+//! MoQ Transport is a pub/sub protocol over QUIC.
+//! While originally designed for live media, MoQ Transport is generic and can be used for other live applications.
+//! The specification is a work in progress and will change.
+//! See the [specification](https://datatracker.ietf.org/doc/draft-ietf-moq-transport/) and [github](https://github.com/moq-wg/moq-transport) for any updates.
+//!
+//! This implementation has some required extensions until the draft stablizes. See: [Extensions](crate::setup::Extensions)
 mod coding;
+mod error;
+
+pub mod cache;
 pub mod message;
-pub mod object;
 pub mod session;
 pub mod setup;
 
 pub use coding::VarInt;
-pub use message::Message;
+pub use error::MoqError;
-pub use session::Session;

moq-transport/src/message/announce.rs

@@ -1,23 +1,30 @@
-use crate::coding::{Decode, DecodeError, Encode, EncodeError};
+use crate::coding::{Decode, DecodeError, Encode, EncodeError, Params};
 
-use bytes::{Buf, BufMut};
+use crate::coding::{AsyncRead, AsyncWrite};
+use crate::setup::Extensions;
 
-#[derive(Debug)]
+/// Sent by the publisher to announce the availability of a group of tracks.
+#[derive(Clone, Debug)]
 pub struct Announce {
-	// The track namespace
+	/// The track namespace
-	pub track_namespace: String,
+	pub namespace: String,
+
+	/// Optional parameters
+	pub params: Params,
 }
 
-impl Decode for Announce {
+impl Announce {
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+	pub async fn decode<R: AsyncRead>(r: &mut R, _ext: &Extensions) -> Result<Self, DecodeError> {
-		let track_namespace = String::decode(r)?;
+		let namespace = String::decode(r).await?;
-		Ok(Self { track_namespace })
+		let params = Params::decode(r).await?;
-	}
+
+		Ok(Self { namespace, params })
 	}
 
-impl Encode for Announce {
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, _ext: &Extensions) -> Result<(), EncodeError> {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
+		self.namespace.encode(w).await?;
-		self.track_namespace.encode(w)?;
+		self.params.encode(w).await?;
+
 		Ok(())
 	}
 }

moq-transport/src/message/announce_error.rs

@@ -1,40 +0,0 @@
-use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
-
-use bytes::{Buf, BufMut};
-
-#[derive(Debug)]
-pub struct AnnounceError {
-	// Echo back the namespace that was announced.
-	// TODO Propose using an ID to save bytes.
-	pub track_namespace: String,
-
-	// An error code.
-	pub code: VarInt,
-
-	// An optional, human-readable reason.
-	pub reason: String,
-}
-
-impl Decode for AnnounceError {
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
-		let track_namespace = String::decode(r)?;
-		let code = VarInt::decode(r)?;
-		let reason = String::decode(r)?;
-
-		Ok(Self {
-			track_namespace,
-			code,
-			reason,
-		})
-	}
-}
-
-impl Encode for AnnounceError {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
-		self.track_namespace.encode(w)?;
-		self.code.encode(w)?;
-		self.reason.encode(w)?;
-
-		Ok(())
-	}
-}

moq-transport/src/message/announce_ok.rs

@@ -1,23 +1,23 @@
-use crate::coding::{Decode, DecodeError, Encode, EncodeError};
+use crate::{
+	coding::{AsyncRead, AsyncWrite, Decode, DecodeError, Encode, EncodeError},
+	setup::Extensions,
+};
 
-use bytes::{Buf, BufMut};
+/// Sent by the subscriber to accept an Announce.
-
+#[derive(Clone, Debug)]
-#[derive(Debug)]
 pub struct AnnounceOk {
 	// Echo back the namespace that was announced.
 	// TODO Propose using an ID to save bytes.
-	pub track_namespace: String,
+	pub namespace: String,
 }
 
-impl Decode for AnnounceOk {
+impl AnnounceOk {
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+	pub async fn decode<R: AsyncRead>(r: &mut R, _ext: &Extensions) -> Result<Self, DecodeError> {
-		let track_namespace = String::decode(r)?;
+		let namespace = String::decode(r).await?;
-		Ok(Self { track_namespace })
+		Ok(Self { namespace })
-	}
 	}
 
-impl Encode for AnnounceOk {
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, _ext: &Extensions) -> Result<(), EncodeError> {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
+		self.namespace.encode(w).await
-		self.track_namespace.encode(w)
 	}
 }

moq-transport/src/message/announce_reset.rs

@@ -0,0 +1,39 @@
+use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
+
+use crate::coding::{AsyncRead, AsyncWrite};
+use crate::setup::Extensions;
+
+/// Sent by the subscriber to reject an Announce.
+#[derive(Clone, Debug)]
+pub struct AnnounceError {
+	// Echo back the namespace that was reset
+	pub namespace: String,
+
+	// An error code.
+	pub code: u32,
+
+	// An optional, human-readable reason.
+	pub reason: String,
+}
+
+impl AnnounceError {
+	pub async fn decode<R: AsyncRead>(r: &mut R, _ext: &Extensions) -> Result<Self, DecodeError> {
+		let namespace = String::decode(r).await?;
+		let code = VarInt::decode(r).await?.try_into()?;
+		let reason = String::decode(r).await?;
+
+		Ok(Self {
+			namespace,
+			code,
+			reason,
+		})
+	}
+
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, _ext: &Extensions) -> Result<(), EncodeError> {
+		self.namespace.encode(w).await?;
+		VarInt::from_u32(self.code).encode(w).await?;
+		self.reason.encode(w).await?;
+
+		Ok(())
+	}
+}

moq-transport/src/message/go_away.rs

@@ -1,21 +1,21 @@
 use crate::coding::{Decode, DecodeError, Encode, EncodeError};
 
-use bytes::{Buf, BufMut};
+use crate::coding::{AsyncRead, AsyncWrite};
+use crate::setup::Extensions;
 
-#[derive(Debug)]
+/// Sent by the server to indicate that the client should connect to a different server.
+#[derive(Clone, Debug)]
 pub struct GoAway {
 	pub url: String,
 }
 
-impl Decode for GoAway {
+impl GoAway {
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+	pub async fn decode<R: AsyncRead>(r: &mut R, _ext: &Extensions) -> Result<Self, DecodeError> {
-		let url = String::decode(r)?;
+		let url = String::decode(r).await?;
 		Ok(Self { url })
 	}
-}
 
-impl Encode for GoAway {
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, _ext: &Extensions) -> Result<(), EncodeError> {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
+		self.url.encode(w).await
-		self.url.encode(w)
 	}
 }

moq-transport/src/message/mod.rs

@@ -1,67 +1,112 @@
+//! Low-level message sent over the wire, as defined in the specification.
+//!
+//! All of these messages are sent over a bidirectional QUIC stream.
+//! This introduces some head-of-line blocking but preserves ordering.
+//! The only exception are OBJECT "messages", which are sent over dedicated QUIC streams.
+//!
+//! Messages sent by the publisher:
+//! - [Announce]
+//! - [Unannounce]
+//! - [SubscribeOk]
+//! - [SubscribeError]
+//! - [SubscribeReset]
+//! - [Object]
+//!
+//! Messages sent by the subscriber:
+//! - [Subscribe]
+//! - [Unsubscribe]
+//! - [AnnounceOk]
+//! - [AnnounceError]
+//!
+//! Example flow:
+//! ```test
+//!  -> ANNOUNCE        namespace="foo"
+//!  <- ANNOUNCE_OK     namespace="foo"
+//!  <- SUBSCRIBE       id=0 namespace="foo" name="bar"
+//!  -> SUBSCRIBE_OK    id=0
+//!  -> OBJECT          id=0 sequence=69 priority=4 expires=30
+//!  -> OBJECT          id=0 sequence=70 priority=4 expires=30
+//!  -> OBJECT          id=0 sequence=70 priority=4 expires=30
+//!  <- SUBSCRIBE_STOP  id=0
+//!  -> SUBSCRIBE_RESET id=0 code=206 reason="closed by peer"
+//! ```
 mod announce;
-mod announce_error;
 mod announce_ok;
+mod announce_reset;
 mod go_away;
-mod receiver;
+mod object;
-mod sender;
 mod subscribe;
 mod subscribe_error;
+mod subscribe_fin;
 mod subscribe_ok;
+mod subscribe_reset;
+mod unannounce;
+mod unsubscribe;
 
 pub use announce::*;
-pub use announce_error::*;
 pub use announce_ok::*;
+pub use announce_reset::*;
 pub use go_away::*;
-pub use receiver::*;
+pub use object::*;
-pub use sender::*;
 pub use subscribe::*;
 pub use subscribe_error::*;
+pub use subscribe_fin::*;
 pub use subscribe_ok::*;
+pub use subscribe_reset::*;
+pub use unannounce::*;
+pub use unsubscribe::*;
 
 use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
-use crate::setup;
 
-use bytes::{Buf, BufMut};
 use std::fmt;
 
-// NOTE: This is forked from moq-transport-00.
+use crate::coding::{AsyncRead, AsyncWrite};
-//   1. SETUP role indicates local support ("I can subscribe"), not remote support ("server must publish")
+use crate::setup::Extensions;
-//   2. SETUP_SERVER is id=2 to disambiguate
-//   3. messages do not have a specified length.
-//   4. messages are sent over a single bidrectional stream (after SETUP), not unidirectional streams.
-//   5. SUBSCRIBE specifies the track_id, not SUBSCRIBE_OK
-//   6. optional parameters are written in order, and zero when unset (setup, announce, subscribe)
 
 // Use a macro to generate the message types rather than copy-paste.
 // This implements a decode/encode method that uses the specified type.
 macro_rules! message_types {
     {$($name:ident = $val:expr,)*} => {
+		/// All supported message types.
+		#[derive(Clone)]
 		pub enum Message {
 			$($name($name)),*
 		}
 
-
+		impl Message {
-		impl Decode for Message {
+			pub async fn decode<R: AsyncRead>(r: &mut R, ext: &Extensions) -> Result<Self, DecodeError> {
-			fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+				let t = VarInt::decode(r).await?;
-				let t = VarInt::decode(r)?;
 
 				match t.into_inner() {
 					$($val => {
-						let msg = $name::decode(r)?;
+						let msg = $name::decode(r, ext).await?;
 						Ok(Self::$name(msg))
 					})*
-					_ => Err(DecodeError::InvalidType(t)),
+					_ => Err(DecodeError::InvalidMessage(t)),
-				}
 				}
 			}
 
-
+			pub async fn encode<W: AsyncWrite>(&self, w: &mut W, ext: &Extensions) -> Result<(), EncodeError> {
-		impl Encode for Message {
-			fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
 				match self {
 					$(Self::$name(ref m) => {
-						VarInt::from_u32($val).encode(w)?;
+						VarInt::from_u32($val).encode(w).await?;
-						m.encode(w)
+						m.encode(w, ext).await
+					},)*
+				}
+			}
+
+			pub fn id(&self) -> VarInt {
+				match self {
+					$(Self::$name(_) => {
+						VarInt::from_u32($val)
+					},)*
+				}
+			}
+
+			pub fn name(&self) -> &'static str {
+				match self {
+					$(Self::$name(_) => {
+						stringify!($name)
 					},)*
 				}
 			}
@@ -84,21 +129,32 @@ macro_rules! message_types {
     }
 }
 
-// Just so we can use the macro above.
-type SetupClient = setup::Client;
-type SetupServer = setup::Server;
-
 // Each message is prefixed with the given VarInt type.
 message_types! {
 	// NOTE: Object and Setup are in other modules.
 	// Object = 0x0
-	SetupClient = 0x1,
+	// ObjectUnbounded = 0x2
-	SetupServer = 0x2,
+	// SetupClient = 0x40
+	// SetupServer = 0x41
+
+	// SUBSCRIBE family, sent by subscriber
 	Subscribe = 0x3,
+	Unsubscribe = 0xa,
+
+	// SUBSCRIBE family, sent by publisher
 	SubscribeOk = 0x4,
 	SubscribeError = 0x5,
+	SubscribeFin = 0xb,
+	SubscribeReset = 0xc,
+
+	// ANNOUNCE family, sent by publisher
 	Announce = 0x6,
+	Unannounce = 0x9,
+
+	// ANNOUNCE family, sent by subscriber
 	AnnounceOk = 0x7,
 	AnnounceError = 0x8,
+
+	// Misc
 	GoAway = 0x10,
 }

moq-transport/src/message/object.rs

@@ -0,0 +1,108 @@
+use std::{io, time};
+
+use tokio::io::AsyncReadExt;
+
+use crate::coding::{AsyncRead, AsyncWrite};
+use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
+use crate::setup;
+
+/// Sent by the publisher as the header of each data stream.
+#[derive(Clone, Debug)]
+pub struct Object {
+	// An ID for this track.
+	// Proposal: https://github.com/moq-wg/moq-transport/issues/209
+	pub track: VarInt,
+
+	// The sequence number within the track.
+	pub group: VarInt,
+
+	// The sequence number within the group.
+	pub sequence: VarInt,
+
+	// The priority, where **smaller** values are sent first.
+	pub priority: u32,
+
+	// Cache the object for at most this many seconds.
+	// Zero means never expire.
+	pub expires: Option<time::Duration>,
+
+	/// An optional size, allowing multiple OBJECTs on the same stream.
+	pub size: Option<VarInt>,
+}
+
+impl Object {
+	pub async fn decode<R: AsyncRead>(r: &mut R, extensions: &setup::Extensions) -> Result<Self, DecodeError> {
+		// Try reading the first byte, returning a special error if the stream naturally ended.
+		let typ = match r.read_u8().await {
+			Ok(b) => VarInt::decode_byte(b, r).await?,
+			Err(e) if e.kind() == io::ErrorKind::UnexpectedEof => return Err(DecodeError::Final),
+			Err(e) => return Err(e.into()),
+		};
+
+		let size_present = match typ.into_inner() {
+			0 => false,
+			2 => true,
+			_ => return Err(DecodeError::InvalidMessage(typ)),
+		};
+
+		let track = VarInt::decode(r).await?;
+		let group = VarInt::decode(r).await?;
+		let sequence = VarInt::decode(r).await?;
+		let priority = VarInt::decode(r).await?.try_into()?;
+
+		let expires = match extensions.object_expires {
+			true => match VarInt::decode(r).await?.into_inner() {
+				0 => None,
+				secs => Some(time::Duration::from_secs(secs)),
+			},
+			false => None,
+		};
+
+		// The presence of the size field depends on the type.
+		let size = match size_present {
+			true => Some(VarInt::decode(r).await?),
+			false => None,
+		};
+
+		Ok(Self {
+			track,
+			group,
+			sequence,
+			priority,
+			expires,
+			size,
+		})
+	}
+
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, extensions: &setup::Extensions) -> Result<(), EncodeError> {
+		// The kind changes based on the presence of the size.
+		let kind = match self.size {
+			Some(_) => VarInt::from_u32(2),
+			None => VarInt::ZERO,
+		};
+
+		kind.encode(w).await?;
+		self.track.encode(w).await?;
+		self.group.encode(w).await?;
+		self.sequence.encode(w).await?;
+		VarInt::from_u32(self.priority).encode(w).await?;
+
+		// Round up if there's any decimal points.
+		let expires = match self.expires {
+			None => 0,
+			Some(time::Duration::ZERO) => return Err(EncodeError::InvalidValue), // there's no way of expressing zero currently.
+			Some(expires) if expires.subsec_nanos() > 0 => expires.as_secs() + 1,
+			Some(expires) => expires.as_secs(),
+		};
+
+		if extensions.object_expires {
+			VarInt::try_from(expires)?.encode(w).await?;
+		}
+
+		if let Some(size) = self.size {
+			size.encode(w).await?;
+		}
+
+		Ok(())
+	}
+}

moq-transport/src/message/receiver.rs

@@ -1,49 +0,0 @@
-use crate::coding::{Decode, DecodeError};
-use crate::message::Message;
-
-use bytes::{Buf, BytesMut};
-
-use std::io::Cursor;
-
-use webtransport_generic::AsyncRecvStream;
-
-pub struct Receiver<R>
-where
-	R: AsyncRecvStream, // TODO take RecvStream instead
-{
-	stream: R,
-	buf: BytesMut, // data we've read but haven't fully decoded yet
-}
-
-impl<R> Receiver<R>
-where
-	R: AsyncRecvStream,
-{
-	pub fn new(stream: R) -> Self {
-		Self {
-			buf: BytesMut::new(),
-			stream,
-		}
-	}
-
-	// Read the next full message from the stream.
-	pub async fn recv(&mut self) -> anyhow::Result<Message> {
-		loop {
-			// Read the contents of the buffer
-			let mut peek = Cursor::new(&self.buf);
-
-			match Message::decode(&mut peek) {
-				Ok(msg) => {
-					// We've successfully decoded a message, so we can advance the buffer.
-					self.buf.advance(peek.position() as usize);
-					return Ok(msg);
-				}
-				Err(DecodeError::UnexpectedEnd) => {
-					// The decode failed, so we need to append more data.
-					self.stream.recv(&mut self.buf).await?;
-				}
-				Err(e) => return Err(e.into()),
-			}
-		}
-	}
-}

moq-transport/src/message/sender.rs

@@ -1,68 +0,0 @@
-use crate::coding::Encode;
-use crate::message::Message;
-
-use bytes::BytesMut;
-
-use webtransport_generic::AsyncSendStream;
-
-pub struct Sender<S>
-where
-	S: AsyncSendStream, // TODO take SendStream instead
-{
-	stream: S,
-	buf: BytesMut, // reuse a buffer to encode messages.
-}
-
-impl<S> Sender<S>
-where
-	S: AsyncSendStream,
-{
-	pub fn new(stream: S) -> Self {
-		Self {
-			buf: BytesMut::new(),
-			stream,
-		}
-	}
-
-	pub async fn send<T: Into<Message>>(&mut self, msg: T) -> anyhow::Result<()> {
-		let msg = msg.into();
-
-		self.buf.clear();
-		msg.encode(&mut self.buf)?;
-
-		self.stream.send(&mut self.buf).await?;
-
-		Ok(())
-	}
-
-	/*
-	// Helper that lets multiple threads send control messages.
-	pub fn share(self) -> ControlShared<S> {
-		ControlShared {
-			stream: Arc::new(Mutex::new(self)),
-		}
-	}
-	*/
-}
-
-/*
-// Helper that allows multiple threads to send control messages.
-// There's no equivalent for receiving since only one thread should be receiving at a time.
-#[derive(Clone)]
-pub struct SendControlShared<S>
-where
-	S: AsyncSendStream,
-{
-	stream: Arc<Mutex<SendControl<S>>>,
-}
-
-impl<S> SendControlShared<S>
-where
-	S: AsyncSendStream,
-{
-	pub async fn send<T: Into<Message>>(&mut self, msg: T) -> anyhow::Result<()> {
-		let mut stream = self.stream.lock().await;
-		stream.send(msg).await
-	}
-}
-*/

moq-transport/src/message/subscribe.rs

@@ -1,39 +1,141 @@
-use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
+use crate::coding::{Decode, DecodeError, Encode, EncodeError, Params, VarInt};
 
-use bytes::{Buf, BufMut};
+use crate::coding::{AsyncRead, AsyncWrite};
+use crate::setup::Extensions;
 
-#[derive(Debug)]
+/// Sent by the subscriber to request all future objects for the given track.
+///
+/// Objects will use the provided ID instead of the full track name, to save bytes.
+#[derive(Clone, Debug)]
 pub struct Subscribe {
-	// An ID we choose so we can map to the track_name.
+	/// An ID we choose so we can map to the track_name.
 	// Proposal: https://github.com/moq-wg/moq-transport/issues/209
-	pub track_id: VarInt,
+	pub id: VarInt,
 
-	// The track namespace.
+	/// The track namespace.
-	pub track_namespace: String,
+	///
+	/// Must be None if `extensions.subscribe_split` is false.
+	pub namespace: Option<String>,
 
-	// The track name.
+	/// The track name.
-	pub track_name: String,
+	pub name: String,
+
+	/// The start/end group/object.
+	pub start_group: SubscribeLocation,
+	pub start_object: SubscribeLocation,
+	pub end_group: SubscribeLocation,
+	pub end_object: SubscribeLocation,
+
+	/// Optional parameters
+	pub params: Params,
 }
 
-impl Decode for Subscribe {
+impl Subscribe {
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+	pub async fn decode<R: AsyncRead>(r: &mut R, ext: &Extensions) -> Result<Self, DecodeError> {
-		let track_id = VarInt::decode(r)?;
+		let id = VarInt::decode(r).await?;
-		let track_namespace = String::decode(r)?;
+
-		let track_name = String::decode(r)?;
+		let namespace = match ext.subscribe_split {
+			true => Some(String::decode(r).await?),
+			false => None,
+		};
+
+		let name = String::decode(r).await?;
+
+		let start_group = SubscribeLocation::decode(r).await?;
+		let start_object = SubscribeLocation::decode(r).await?;
+		let end_group = SubscribeLocation::decode(r).await?;
+		let end_object = SubscribeLocation::decode(r).await?;
+
+		// You can't have a start object without a start group.
+		if start_group == SubscribeLocation::None && start_object != SubscribeLocation::None {
+			return Err(DecodeError::InvalidSubscribeLocation);
+		}
+
+		// You can't have an end object without an end group.
+		if end_group == SubscribeLocation::None && end_object != SubscribeLocation::None {
+			return Err(DecodeError::InvalidSubscribeLocation);
+		}
+
+		// NOTE: There's some more location restrictions in the draft, but they're enforced at a higher level.
+
+		let params = Params::decode(r).await?;
 
 		Ok(Self {
-			track_id,
+			id,
-			track_namespace,
+			namespace,
-			track_name,
+			name,
+			start_group,
+			start_object,
+			end_group,
+			end_object,
+			params,
 		})
 	}
+
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, ext: &Extensions) -> Result<(), EncodeError> {
+		self.id.encode(w).await?;
+
+		if self.namespace.is_some() != ext.subscribe_split {
+			panic!("namespace must be None if subscribe_split is false");
 		}
 
-impl Encode for Subscribe {
+		if ext.subscribe_split {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
+			self.namespace.as_ref().unwrap().encode(w).await?;
-		self.track_id.encode(w)?;
+		}
-		self.track_namespace.encode(w)?;
+
-		self.track_name.encode(w)?;
+		self.name.encode(w).await?;
+
+		self.start_group.encode(w).await?;
+		self.start_object.encode(w).await?;
+		self.end_group.encode(w).await?;
+		self.end_object.encode(w).await?;
+
+		self.params.encode(w).await?;
+
+		Ok(())
+	}
+}
+
+/// Signal where the subscription should begin, relative to the current cache.
+#[derive(Clone, Debug, PartialEq)]
+pub enum SubscribeLocation {
+	None,
+	Absolute(VarInt),
+	Latest(VarInt),
+	Future(VarInt),
+}
+
+impl SubscribeLocation {
+	pub async fn decode<R: AsyncRead>(r: &mut R) -> Result<Self, DecodeError> {
+		let kind = VarInt::decode(r).await?;
+
+		match kind.into_inner() {
+			0 => Ok(Self::None),
+			1 => Ok(Self::Absolute(VarInt::decode(r).await?)),
+			2 => Ok(Self::Latest(VarInt::decode(r).await?)),
+			3 => Ok(Self::Future(VarInt::decode(r).await?)),
+			_ => Err(DecodeError::InvalidSubscribeLocation),
+		}
+	}
+
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W) -> Result<(), EncodeError> {
+		match self {
+			Self::None => {
+				VarInt::from_u32(0).encode(w).await?;
+			}
+			Self::Absolute(val) => {
+				VarInt::from_u32(1).encode(w).await?;
+				val.encode(w).await?;
+			}
+			Self::Latest(val) => {
+				VarInt::from_u32(2).encode(w).await?;
+				val.encode(w).await?;
+			}
+			Self::Future(val) => {
+				VarInt::from_u32(3).encode(w).await?;
+				val.encode(w).await?;
+			}
+		}
 
 		Ok(())
 	}

moq-transport/src/message/subscribe_error.rs

@@ -1,36 +1,35 @@
+use crate::coding::{AsyncRead, AsyncWrite};
 use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
+use crate::setup::Extensions;
 
-use bytes::{Buf, BufMut};
+/// Sent by the publisher to reject a Subscribe.
-
+#[derive(Clone, Debug)]
-#[derive(Debug)]
 pub struct SubscribeError {
 	// NOTE: No full track name because of this proposal: https://github.com/moq-wg/moq-transport/issues/209
 
-	// The ID for this track.
+	// The ID for this subscription.
-	pub track_id: VarInt,
+	pub id: VarInt,
 
 	// An error code.
-	pub code: VarInt,
+	pub code: u32,
 
 	// An optional, human-readable reason.
 	pub reason: String,
 }
 
-impl Decode for SubscribeError {
+impl SubscribeError {
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+	pub async fn decode<R: AsyncRead>(r: &mut R, _ext: &Extensions) -> Result<Self, DecodeError> {
-		let track_id = VarInt::decode(r)?;
+		let id = VarInt::decode(r).await?;
-		let code = VarInt::decode(r)?;
+		let code = VarInt::decode(r).await?.try_into()?;
-		let reason = String::decode(r)?;
+		let reason = String::decode(r).await?;
 
-		Ok(Self { track_id, code, reason })
+		Ok(Self { id, code, reason })
-	}
 	}
 
-impl Encode for SubscribeError {
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, _ext: &Extensions) -> Result<(), EncodeError> {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
+		self.id.encode(w).await?;
-		self.track_id.encode(w)?;
+		VarInt::from_u32(self.code).encode(w).await?;
-		self.code.encode(w)?;
+		self.reason.encode(w).await?;
-		self.reason.encode(w)?;
 
 		Ok(())
 	}

moq-transport/src/message/subscribe_fin.rs

@@ -0,0 +1,37 @@
+use crate::coding::{AsyncRead, AsyncWrite};
+use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
+use crate::setup::Extensions;
+
+/// Sent by the publisher to cleanly terminate a Subscribe.
+#[derive(Clone, Debug)]
+pub struct SubscribeFin {
+	// NOTE: No full track name because of this proposal: https://github.com/moq-wg/moq-transport/issues/209
+	/// The ID for this subscription.
+	pub id: VarInt,
+
+	/// The final group/object sent on this subscription.
+	pub final_group: VarInt,
+	pub final_object: VarInt,
+}
+
+impl SubscribeFin {
+	pub async fn decode<R: AsyncRead>(r: &mut R, _ext: &Extensions) -> Result<Self, DecodeError> {
+		let id = VarInt::decode(r).await?;
+		let final_group = VarInt::decode(r).await?;
+		let final_object = VarInt::decode(r).await?;
+
+		Ok(Self {
+			id,
+			final_group,
+			final_object,
+		})
+	}
+
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, _ext: &Extensions) -> Result<(), EncodeError> {
+		self.id.encode(w).await?;
+		self.final_group.encode(w).await?;
+		self.final_object.encode(w).await?;
+
+		Ok(())
+	}
+}

moq-transport/src/message/subscribe_ok.rs

@@ -1,36 +1,31 @@
 use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
 
-use std::time::Duration;
+use crate::coding::{AsyncRead, AsyncWrite};
+use crate::setup::Extensions;
 
-use bytes::{Buf, BufMut};
+/// Sent by the publisher to accept a Subscribe.
-
+#[derive(Clone, Debug)]
-#[derive(Debug)]
 pub struct SubscribeOk {
 	// NOTE: No full track name because of this proposal: https://github.com/moq-wg/moq-transport/issues/209
+	/// The ID for this track.
+	pub id: VarInt,
 
-	// The ID for this track.
+	/// The subscription will expire in this many milliseconds.
-	pub track_id: VarInt,
+	pub expires: VarInt,
-
-	// The subscription will end after this duration has elapsed.
-	// A value of zero is invalid.
-	pub expires: Option<Duration>,
 }
 
-impl Decode for SubscribeOk {
+impl SubscribeOk {
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
+	pub async fn decode<R: AsyncRead>(r: &mut R, _ext: &Extensions) -> Result<Self, DecodeError> {
-		let track_id = VarInt::decode(r)?;
+		let id = VarInt::decode(r).await?;
-		let expires = Duration::decode(r)?;
+		let expires = VarInt::decode(r).await?;
-		let expires = if expires == Duration::ZERO { None } else { Some(expires) };
+		Ok(Self { id, expires })
-
-		Ok(Self { track_id, expires })
 	}
 }
 
-impl Encode for SubscribeOk {
+impl SubscribeOk {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, _ext: &Extensions) -> Result<(), EncodeError> {
-		self.track_id.encode(w)?;
+		self.id.encode(w).await?;
-		self.expires.unwrap_or_default().encode(w)?;
+		self.expires.encode(w).await?;
-
 		Ok(())
 	}
 }

moq-transport/src/message/subscribe_reset.rs

@@ -0,0 +1,50 @@
+use crate::coding::{AsyncRead, AsyncWrite};
+use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
+use crate::setup::Extensions;
+
+/// Sent by the publisher to terminate a Subscribe.
+#[derive(Clone, Debug)]
+pub struct SubscribeReset {
+	// NOTE: No full track name because of this proposal: https://github.com/moq-wg/moq-transport/issues/209
+	/// The ID for this subscription.
+	pub id: VarInt,
+
+	/// An error code.
+	pub code: u32,
+
+	/// An optional, human-readable reason.
+	pub reason: String,
+
+	/// The final group/object sent on this subscription.
+	pub final_group: VarInt,
+	pub final_object: VarInt,
+}
+
+impl SubscribeReset {
+	pub async fn decode<R: AsyncRead>(r: &mut R, _ext: &Extensions) -> Result<Self, DecodeError> {
+		let id = VarInt::decode(r).await?;
+		let code = VarInt::decode(r).await?.try_into()?;
+		let reason = String::decode(r).await?;
+		let final_group = VarInt::decode(r).await?;
+		let final_object = VarInt::decode(r).await?;
+
+		Ok(Self {
+			id,
+			code,
+			reason,
+			final_group,
+			final_object,
+		})
+	}
+
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, _ext: &Extensions) -> Result<(), EncodeError> {
+		self.id.encode(w).await?;
+		VarInt::from_u32(self.code).encode(w).await?;
+		self.reason.encode(w).await?;
+
+		self.final_group.encode(w).await?;
+		self.final_object.encode(w).await?;
+
+		Ok(())
+	}
+}

moq-transport/src/message/unannounce.rs

@@ -0,0 +1,25 @@
+use crate::coding::{Decode, DecodeError, Encode, EncodeError};
+
+use crate::coding::{AsyncRead, AsyncWrite};
+use crate::setup::Extensions;
+
+/// Sent by the publisher to terminate an Announce.
+#[derive(Clone, Debug)]
+pub struct Unannounce {
+	// Echo back the namespace that was reset
+	pub namespace: String,
+}
+
+impl Unannounce {
+	pub async fn decode<R: AsyncRead>(r: &mut R, _ext: &Extensions) -> Result<Self, DecodeError> {
+		let namespace = String::decode(r).await?;
+
+		Ok(Self { namespace })
+	}
+
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, _ext: &Extensions) -> Result<(), EncodeError> {
+		self.namespace.encode(w).await?;
+
+		Ok(())
+	}
+}

moq-transport/src/message/unsubscribe.rs

@@ -0,0 +1,27 @@
+use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
+
+use crate::coding::{AsyncRead, AsyncWrite};
+use crate::setup::Extensions;
+
+/// Sent by the subscriber to terminate a Subscribe.
+#[derive(Clone, Debug)]
+pub struct Unsubscribe {
+	// NOTE: No full track name because of this proposal: https://github.com/moq-wg/moq-transport/issues/209
+
+	// The ID for this subscription.
+	pub id: VarInt,
+}
+
+impl Unsubscribe {
+	pub async fn decode<R: AsyncRead>(r: &mut R, _ext: &Extensions) -> Result<Self, DecodeError> {
+		let id = VarInt::decode(r).await?;
+		Ok(Self { id })
+	}
+}
+
+impl Unsubscribe {
+	pub async fn encode<W: AsyncWrite>(&self, w: &mut W, _ext: &Extensions) -> Result<(), EncodeError> {
+		self.id.encode(w).await?;
+		Ok(())
+	}
+}

moq-transport/src/object/header.rs

@@ -1,53 +0,0 @@
-use crate::coding::{Decode, DecodeError, Encode, EncodeError, VarInt};
-use bytes::{Buf, BufMut};
-
-#[derive(Debug)]
-pub struct Header {
-	// An ID for this track.
-	// Proposal: https://github.com/moq-wg/moq-transport/issues/209
-	pub track: VarInt,
-
-	// The group sequence number.
-	pub group: VarInt,
-
-	// The object sequence number.
-	pub sequence: VarInt,
-
-	// The priority/send order.
-	pub send_order: VarInt,
-}
-
-impl Decode for Header {
-	fn decode<R: Buf>(r: &mut R) -> Result<Self, DecodeError> {
-		let typ = VarInt::decode(r)?;
-		if typ.into_inner() != 0 {
-			return Err(DecodeError::InvalidType(typ));
-		}
-
-		// NOTE: size has been omitted
-
-		let track = VarInt::decode(r)?;
-		let group = VarInt::decode(r)?;
-		let sequence = VarInt::decode(r)?;
-		let send_order = VarInt::decode(r)?;
-
-		Ok(Self {
-			track,
-			group,
-			sequence,
-			send_order,
-		})
-	}
-}
-
-impl Encode for Header {
-	fn encode<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError> {
-		VarInt::from_u32(0).encode(w)?;
-		self.track.encode(w)?;
-		self.group.encode(w)?;
-		self.sequence.encode(w)?;
-		self.send_order.encode(w)?;
-
-		Ok(())
-	}
-}

moq-transport/src/object/mod.rs

@@ -1,7 +0,0 @@
-mod header;
-mod receiver;
-mod sender;
-
-pub use header::*;
-pub use receiver::*;
-pub use sender::*;

moq-transport/src/object/receiver.rs

@@ -1,128 +0,0 @@
-use std::io::Cursor;
-use std::task::{self, Poll};
-
-use crate::coding::{Decode, DecodeError};
-use crate::object::Header;
-
-use anyhow::Context;
-use bytes::{Buf, BufMut, Bytes, BytesMut};
-use tokio::task::JoinSet;
-
-use webtransport_generic::RecvStream as GenericRecvStream;
-use webtransport_generic::{AsyncRecvStream, AsyncSession};
-
-pub struct Receiver<S>
-where
-	S: AsyncSession,
-{
-	session: S,
-
-	// Streams that we've accepted but haven't read the header from yet.
-	streams: JoinSet<anyhow::Result<(Header, RecvStream<S::RecvStream>)>>,
-}
-
-impl<S> Receiver<S>
-where
-	S: AsyncSession,
-	S::RecvStream: AsyncRecvStream,
-{
-	pub fn new(session: S) -> Self {
-		Self {
-			session,
-			streams: JoinSet::new(),
-		}
-	}
-
-	pub async fn recv(&mut self) -> anyhow::Result<(Header, RecvStream<S::RecvStream>)> {
-		loop {
-			tokio::select! {
-				res = self.session.accept_uni() => {
-					let stream = res.context("failed to accept stream")?;
-					self.streams.spawn(async move { Self::read(stream).await });
-				},
-				res = self.streams.join_next(), if !self.streams.is_empty() => {
-					return res.unwrap().context("failed to run join set")?;
-				}
-			}
-		}
-	}
-
-	async fn read(mut stream: S::RecvStream) -> anyhow::Result<(Header, RecvStream<S::RecvStream>)> {
-		let mut buf = BytesMut::new();
-
-		loop {
-			// Read more data into the buffer.
-			stream.recv(&mut buf).await?;
-
-			// Use a cursor to read the buffer and remember how much we read.
-			let mut read = Cursor::new(&mut buf);
-
-			let header = match Header::decode(&mut read) {
-				Ok(header) => header,
-				Err(DecodeError::UnexpectedEnd) => continue,
-				Err(err) => return Err(err.into()),
-			};
-
-			// We parsed a full header, advance the buffer.
-			let size = read.position() as usize;
-			buf.advance(size);
-			let buf = buf.freeze();
-
-			// log::info!("received stream: {:?}", header);
-
-			let stream = RecvStream::new(buf, stream);
-
-			return Ok((header, stream));
-		}
-	}
-}
-
-// Unfortunately, we need to wrap RecvStream with a buffer since moq-transport::Coding only supports buffered reads.
-// We first serve any data in the buffer, then we poll the stream.
-// TODO fix this so we don't need the wrapper.
-pub struct RecvStream<R>
-where
-	R: GenericRecvStream,
-{
-	buf: Bytes,
-	stream: R,
-}
-
-impl<R> RecvStream<R>
-where
-	R: GenericRecvStream,
-{
-	pub(crate) fn new(buf: Bytes, stream: R) -> Self {
-		Self { buf, stream }
-	}
-
-	pub fn stop(&mut self, code: u32) {
-		self.stream.stop(code)
-	}
-}
-
-impl<R> GenericRecvStream for RecvStream<R>
-where
-	R: GenericRecvStream,
-{
-	type Error = R::Error;
-
-	fn poll_recv<B: BufMut>(
-		&mut self,
-		cx: &mut task::Context<'_>,
-		buf: &mut B,
-	) -> Poll<Result<Option<usize>, Self::Error>> {
-		if !self.buf.is_empty() {
-			let size = self.buf.len();
-			buf.put(&mut self.buf);
-			let size = size - self.buf.len();
-			Poll::Ready(Ok(Some(size)))
-		} else {
-			self.stream.poll_recv(cx, buf)
-		}
-	}
-
-	fn stop(&mut self, error_code: u32) {
-		self.stream.stop(error_code)
-	}
-}

moq-transport/src/object/sender.rs

@@ -1,229 +0,0 @@
-use std::sync::{Mutex, Weak};
-use std::task::{self, Poll};
-use std::{collections::BinaryHeap, sync::Arc};
-
-use anyhow::Context;
-use bytes::{Buf, BytesMut};
-
-use crate::coding::Encode;
-use crate::object::Header;
-
-use webtransport_generic::SendStream as GenericSendStream;
-use webtransport_generic::{AsyncSendStream, AsyncSession};
-
-// Allow this to be cloned so we can have multiple senders.
-pub struct Sender<S>
-where
-	S: AsyncSession,
-	S::SendStream: AsyncSendStream,
-{
-	// The session.
-	session: S,
-
-	// A reusable buffer for the stream header.
-	buf: BytesMut,
-
-	// Register new streams with an inner object that will prioritize them.
-	inner: Arc<Mutex<SenderInner<S::SendStream>>>,
-}
-
-impl<S> Sender<S>
-where
-	S: AsyncSession,
-	S::SendStream: AsyncSendStream,
-{
-	pub fn new(session: S) -> Self {
-		let inner = SenderInner::new();
-		Self {
-			session,
-			buf: BytesMut::new(),
-			inner: Arc::new(Mutex::new(inner)),
-		}
-	}
-
-	pub async fn open(&mut self, header: Header) -> anyhow::Result<SendStream<S::SendStream>> {
-		let stream = self.session.open_uni().await.context("failed to open uni stream")?;
-
-		let mut stream = {
-			let mut inner = self.inner.lock().unwrap();
-			inner.register(stream, header.send_order.into_inner())?
-		};
-
-		self.buf.clear();
-		header.encode(&mut self.buf).unwrap();
-		stream.send_all(&mut self.buf).await.context("failed to write header")?;
-
-		// log::info!("created stream: {:?}", header);
-
-		header.encode(&mut self.buf).unwrap();
-		stream.send_all(&mut self.buf).await.context("failed to write header")?;
-
-		Ok(stream)
-	}
-}
-
-impl<S> Clone for Sender<S>
-where
-	S: AsyncSession,
-	S::SendStream: AsyncSendStream,
-{
-	fn clone(&self) -> Self {
-		Sender {
-			session: self.session.clone(),
-			buf: BytesMut::new(),
-			inner: self.inner.clone(),
-		}
-	}
-}
-
-struct SenderInner<S>
-where
-	S: GenericSendStream,
-{
-	// Quinn supports a i32 for priority, but the wire format is a u64.
-	// Our work around is to keep a list of streams in priority order and use the index as the priority.
-	// This involves more work, so TODO either increase the Quinn size or reduce the wire size.
-	ordered: BinaryHeap<SendOrder<S>>,
-	ordered_swap: BinaryHeap<SendOrder<S>>, // reuse memory to avoid allocations
-}
-
-impl<S> SenderInner<S>
-where
-	S: GenericSendStream,
-{
-	fn new() -> Self {
-		Self {
-			ordered: BinaryHeap::new(),
-			ordered_swap: BinaryHeap::new(),
-		}
-	}
-
-	pub fn register(&mut self, stream: S, order: u64) -> anyhow::Result<SendStream<S>> {
-		let stream = SendStream::new(stream);
-		let order = SendOrder::new(&stream, order);
-
-		// Add the priority to our existing list.
-		self.ordered.push(order);
-
-		// Loop through the list and update the priorities of any still active streams.
-		let mut index = 0;
-		while let Some(stream) = self.ordered.pop() {
-			if stream.set_priority(index).is_some() {
-				// Add the stream to the new list so it'll be in sorted order.
-				self.ordered_swap.push(stream);
-				index += 1;
-			}
-		}
-
-		// Swap the lists so we can reuse the memory.
-		std::mem::swap(&mut self.ordered, &mut self.ordered_swap);
-
-		Ok(stream)
-	}
-}
-
-struct SendOrder<S>
-where
-	S: GenericSendStream,
-{
-	// We use Weak here so we don't prevent the stream from being closed when dereferenced.
-	// set_priority() will return None if the stream was closed.
-	stream: Weak<Mutex<S>>,
-	order: u64,
-}
-
-impl<S> SendOrder<S>
-where
-	S: GenericSendStream,
-{
-	fn new(stream: &SendStream<S>, order: u64) -> Self {
-		let stream = stream.weak();
-		Self { stream, order }
-	}
-
-	fn set_priority(&self, index: i32) -> Option<()> {
-		let stream = self.stream.upgrade()?;
-		let mut stream = stream.lock().unwrap();
-		stream.set_priority(index);
-		Some(())
-	}
-}
-
-impl<S> PartialEq for SendOrder<S>
-where
-	S: GenericSendStream,
-{
-	fn eq(&self, other: &Self) -> bool {
-		self.order == other.order
-	}
-}
-
-impl<S> Eq for SendOrder<S> where S: GenericSendStream {}
-
-impl<S> PartialOrd for SendOrder<S>
-where
-	S: GenericSendStream,
-{
-	fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-		// We reverse the order so the lower send order is higher priority.
-		other.order.partial_cmp(&self.order)
-	}
-}
-
-impl<S> Ord for SendOrder<S>
-where
-	S: GenericSendStream,
-{
-	fn cmp(&self, other: &Self) -> std::cmp::Ordering {
-		// We reverse the order so the lower send order is higher priority.
-		other.order.cmp(&self.order)
-	}
-}
-
-// Ugh, so we need to wrap SendStream with a mutex because we need to be able to call set_priority on it.
-// The problem is that set_priority takes a i32, while send_order is a VarInt
-// So the solution is to maintain a priority queue of active streams and constantly update the priority with their index.
-// So the library might update the priority of the stream at any point, while the application might similtaniously write to it.
-pub struct SendStream<S>
-where
-	S: GenericSendStream,
-{
-	// All SendStream methods are &mut, so we need to wrap them with an internal mutex.
-	inner: Arc<Mutex<S>>,
-}
-
-impl<S> SendStream<S>
-where
-	S: GenericSendStream,
-{
-	pub(crate) fn new(stream: S) -> Self {
-		Self {
-			inner: Arc::new(Mutex::new(stream)),
-		}
-	}
-
-	pub fn weak(&self) -> Weak<Mutex<S>> {
-		Arc::<Mutex<S>>::downgrade(&self.inner)
-	}
-}
-
-impl<S> GenericSendStream for SendStream<S>
-where
-	S: GenericSendStream,
-{
-	type Error = S::Error;
-
-	fn poll_send<B: Buf>(&mut self, cx: &mut task::Context<'_>, buf: &mut B) -> Poll<Result<usize, Self::Error>> {
-		self.inner.lock().unwrap().poll_send(cx, buf)
-	}
-
-	fn reset(&mut self, reset_code: u32) {
-		self.inner.lock().unwrap().reset(reset_code)
-	}
-
-	// The application should NOT use this method.
-	// The library will automatically set the stream priority on creation based on the header.
-	fn set_priority(&mut self, order: i32) {
-		self.inner.lock().unwrap().set_priority(order)
-	}
-}

moq-transport/src/session/client.rs

@@ -0,0 +1,73 @@
+use super::{Control, Publisher, SessionError, Subscriber};
+use crate::{cache::broadcast, setup};
+use webtransport_quinn::Session;
+
+/// An endpoint that connects to a URL to publish and/or consume live streams.
+pub struct Client {}
+
+impl Client {
+	/// Connect using an established WebTransport session, performing the MoQ handshake as a publisher.
+	pub async fn publisher(session: Session, source: broadcast::Subscriber) -> Result<Publisher, SessionError> {
+		let control = Self::send_setup(&session, setup::Role::Publisher).await?;
+		let publisher = Publisher::new(session, control, source);
+		Ok(publisher)
+	}
+
+	/// Connect using an established WebTransport session, performing the MoQ handshake as a subscriber.
+	pub async fn subscriber(session: Session, source: broadcast::Publisher) -> Result<Subscriber, SessionError> {
+		let control = Self::send_setup(&session, setup::Role::Subscriber).await?;
+		let subscriber = Subscriber::new(session, control, source);
+		Ok(subscriber)
+	}
+
+	// TODO support performing both roles
+	/*
+		pub async fn connect(self) -> anyhow::Result<(Publisher, Subscriber)> {
+			self.connect_role(setup::Role::Both).await
+		}
+	*/
+
+	async fn send_setup(session: &Session, role: setup::Role) -> Result<Control, SessionError> {
+		let mut control = session.open_bi().await?;
+
+		let versions: setup::Versions = [setup::Version::DRAFT_01, setup::Version::KIXEL_01].into();
+
+		let client = setup::Client {
+			role,
+			versions: versions.clone(),
+			params: Default::default(),
+
+			// Offer all extensions
+			extensions: setup::Extensions {
+				object_expires: true,
+				subscriber_id: true,
+				subscribe_split: true,
+			},
+		};
+
+		client.encode(&mut control.0).await?;
+
+		let mut server = setup::Server::decode(&mut control.1).await?;
+
+		match server.version {
+			setup::Version::DRAFT_01 => {
+				// We always require this extension
+				server.extensions.require_subscriber_id()?;
+
+				if server.role.is_publisher() {
+					// We only require object expires if we're a subscriber, so we don't cache objects indefinitely.
+					server.extensions.require_object_expires()?;
+				}
+			}
+			setup::Version::KIXEL_01 => {
+				// KIXEL_01 didn't support extensions; all were enabled.
+				server.extensions = client.extensions.clone()
+			}
+			_ => return Err(SessionError::Version(versions, [server.version].into())),
+		}
+
+		let control = Control::new(control.0, control.1, server.extensions);
+
+		Ok(control)
+	}
+}

moq-transport/src/session/control.rs

@@ -0,0 +1,45 @@
+// A helper class to guard sending control messages behind a Mutex.
+
+use std::{fmt, sync::Arc};
+
+use tokio::sync::Mutex;
+use webtransport_quinn::{RecvStream, SendStream};
+
+use super::SessionError;
+use crate::{message::Message, setup::Extensions};
+
+#[derive(Debug, Clone)]
+pub(crate) struct Control {
+	send: Arc<Mutex<SendStream>>,
+	recv: Arc<Mutex<RecvStream>>,
+	pub ext: Extensions,
+}
+
+impl Control {
+	pub fn new(send: SendStream, recv: RecvStream, ext: Extensions) -> Self {
+		Self {
+			send: Arc::new(Mutex::new(send)),
+			recv: Arc::new(Mutex::new(recv)),
+			ext,
+		}
+	}
+
+	pub async fn send<T: Into<Message> + fmt::Debug>(&self, msg: T) -> Result<(), SessionError> {
+		let mut stream = self.send.lock().await;
+		log::info!("sending message: {:?}", msg);
+		msg.into()
+			.encode(&mut *stream, &self.ext)
+			.await
+			.map_err(|e| SessionError::Unknown(e.to_string()))?;
+		Ok(())
+	}
+
+	// It's likely a mistake to call this from two different tasks, but it's easier to just support it.
+	pub async fn recv(&self) -> Result<Message, SessionError> {
+		let mut stream = self.recv.lock().await;
+		let msg = Message::decode(&mut *stream, &self.ext)
+			.await
+			.map_err(|e| SessionError::Unknown(e.to_string()))?;
+		Ok(msg)
+	}
+}

moq-transport/src/session/error.rs

@@ -0,0 +1,101 @@
+use crate::{cache, coding, setup, MoqError, VarInt};
+
+#[derive(thiserror::Error, Debug)]
+pub enum SessionError {
+	#[error("webtransport error: {0}")]
+	Session(#[from] webtransport_quinn::SessionError),
+
+	#[error("cache error: {0}")]
+	Cache(#[from] cache::CacheError),
+
+	#[error("encode error: {0}")]
+	Encode(#[from] coding::EncodeError),
+
+	#[error("decode error: {0}")]
+	Decode(#[from] coding::DecodeError),
+
+	#[error("unsupported versions: client={0:?} server={1:?}")]
+	Version(setup::Versions, setup::Versions),
+
+	#[error("incompatible roles: client={0:?} server={1:?}")]
+	RoleIncompatible(setup::Role, setup::Role),
+
+	/// An error occured while reading from the QUIC stream.
+	#[error("failed to read from stream: {0}")]
+	Read(#[from] webtransport_quinn::ReadError),
+
+	/// An error occured while writing to the QUIC stream.
+	#[error("failed to write to stream: {0}")]
+	Write(#[from] webtransport_quinn::WriteError),
+
+	/// The role negiotiated in the handshake was violated. For example, a publisher sent a SUBSCRIBE, or a subscriber sent an OBJECT.
+	#[error("role violation: msg={0}")]
+	RoleViolation(VarInt),
+
+	/// Our enforced stream mapping was disrespected.
+	#[error("stream mapping conflict")]
+	StreamMapping,
+
+	/// The priority was invalid.
+	#[error("invalid priority: {0}")]
+	InvalidPriority(VarInt),
+
+	/// The size was invalid.
+	#[error("invalid size: {0}")]
+	InvalidSize(VarInt),
+
+	/// A required extension was not offered.
+	#[error("required extension not offered: {0:?}")]
+	RequiredExtension(VarInt),
+
+	/// An unclassified error because I'm lazy. TODO classify these errors
+	#[error("unknown error: {0}")]
+	Unknown(String),
+}
+
+impl MoqError for SessionError {
+	/// An integer code that is sent over the wire.
+	fn code(&self) -> u32 {
+		match self {
+			Self::Cache(err) => err.code(),
+			Self::RoleIncompatible(..) => 406,
+			Self::RoleViolation(..) => 405,
+			Self::StreamMapping => 409,
+			Self::Unknown(_) => 500,
+			Self::Write(_) => 501,
+			Self::Read(_) => 502,
+			Self::Session(_) => 503,
+			Self::Version(..) => 406,
+			Self::Encode(_) => 500,
+			Self::Decode(_) => 500,
+			Self::InvalidPriority(_) => 400,
+			Self::InvalidSize(_) => 400,
+			Self::RequiredExtension(_) => 426,
+		}
+	}
+
+	/// A reason that is sent over the wire.
+	fn reason(&self) -> String {
+		match self {
+			Self::Cache(err) => err.reason(),
+			Self::RoleViolation(kind) => format!("role violation for message type {:?}", kind),
+			Self::RoleIncompatible(client, server) => {
+				format!(
+					"role incompatible: client wanted {:?} but server wanted {:?}",
+					client, server
+				)
+			}
+			Self::Read(err) => format!("read error: {}", err),
+			Self::Write(err) => format!("write error: {}", err),
+			Self::Session(err) => format!("session error: {}", err),
+			Self::Unknown(err) => format!("unknown error: {}", err),
+			Self::Version(client, server) => format!("unsupported versions: client={:?} server={:?}", client, server),
+			Self::Encode(err) => format!("encode error: {}", err),
+			Self::Decode(err) => format!("decode error: {}", err),
+			Self::StreamMapping => "streaming mapping conflict".to_owned(),
+			Self::InvalidPriority(priority) => format!("invalid priority: {}", priority),
+			Self::InvalidSize(size) => format!("invalid size: {}", size),
+			Self::RequiredExtension(id) => format!("required extension was missing: {:?}", id),
+		}
+	}
+}

moq-transport/src/session/mod.rs

@@ -1,109 +1,27 @@
-use anyhow::Context;
+//! A MoQ Transport session, on top of a WebTransport session, on top of a QUIC connection.
+//!
+//! The handshake is relatively simple but split into different steps.
+//! All of these handshakes slightly differ depending on if the endpoint is a client or server.
+//! 1. Complete the QUIC handhake.
+//! 2. Complete the WebTransport handshake.
+//! 3. Complete the MoQ handshake.
+//!
+//! Use [Client] or [Server] for the MoQ handshake depending on the endpoint.
+//! Then, decide if you want to create a [Publisher] or [Subscriber], or both (TODO).
+//!
+//! A [Publisher] can announce broadcasts, which will automatically be served over the network.
+//! A [Subscriber] can subscribe to broadcasts, which will automatically be served over the network.
 
-use crate::{message, object, setup};
+mod client;
-use webtransport_generic::{AsyncRecvStream, AsyncSendStream, AsyncSession};
+mod control;
+mod error;
+mod publisher;
+mod server;
+mod subscriber;
 
-pub struct Session<S>
+pub use client::*;
-where
+pub(crate) use control::*;
-	S: AsyncSession,
+pub use error::*;
-	S::SendStream: AsyncSendStream,
+pub use publisher::*;
-	S::RecvStream: AsyncRecvStream,
+pub use server::*;
-{
+pub use subscriber::*;
-	pub send_control: message::Sender<S::SendStream>,
-	pub recv_control: message::Receiver<S::RecvStream>,
-	pub send_objects: object::Sender<S>,
-	pub recv_objects: object::Receiver<S>,
-}
-
-impl<S> Session<S>
-where
-	S: AsyncSession,
-	S::SendStream: AsyncSendStream,
-	S::RecvStream: AsyncRecvStream,
-{
-	/// Called by a server with an established WebTransport session.
-	// TODO close the session with an error code
-	pub async fn accept(session: S, role: setup::Role) -> anyhow::Result<Self> {
-		let (send, recv) = session.accept_bi().await.context("failed to accept bidi stream")?;
-
-		let mut send_control = message::Sender::new(send);
-		let mut recv_control = message::Receiver::new(recv);
-
-		let setup_client = match recv_control.recv().await.context("failed to read SETUP")? {
-			message::Message::SetupClient(setup) => setup,
-			_ => anyhow::bail!("expected CLIENT SETUP"),
-		};
-
-		setup_client
-			.versions
-			.iter()
-			.find(|version| **version == setup::Version::DRAFT_00)
-			.context("no supported versions")?;
-
-		if !setup_client.role.compatible(role) {
-			anyhow::bail!("incompatible roles: {:?} {:?}", setup_client.role, role);
-		}
-
-		let setup_server = setup::Server {
-			role,
-			version: setup::Version::DRAFT_00,
-		};
-
-		send_control
-			.send(message::Message::SetupServer(setup_server))
-			.await
-			.context("failed to send setup server")?;
-
-		let send_objects = object::Sender::new(session.clone());
-		let recv_objects = object::Receiver::new(session.clone());
-
-		Ok(Session {
-			send_control,
-			recv_control,
-			send_objects,
-			recv_objects,
-		})
-	}
-
-	/// Called by a client with an established WebTransport session.
-	pub async fn connect(session: S, role: setup::Role) -> anyhow::Result<Self> {
-		let (send, recv) = session.open_bi().await.context("failed to oen bidi stream")?;
-
-		let mut send_control = message::Sender::new(send);
-		let mut recv_control = message::Receiver::new(recv);
-
-		let setup_client = setup::Client {
-			role,
-			versions: vec![setup::Version::DRAFT_00].into(),
-			path: "".to_string(),
-		};
-
-		send_control
-			.send(message::Message::SetupClient(setup_client))
-			.await
-			.context("failed to send SETUP CLIENT")?;
-
-		let setup_server = match recv_control.recv().await.context("failed to read SETUP")? {
-			message::Message::SetupServer(setup) => setup,
-			_ => anyhow::bail!("expected SERVER SETUP"),
-		};
-
-		if setup_server.version != setup::Version::DRAFT_00 {
-			anyhow::bail!("unsupported version: {:?}", setup_server.version);
-		}
-
-		if !setup_server.role.compatible(role) {
-			anyhow::bail!("incompatible roles: {:?} {:?}", role, setup_server.role);
-		}
-
-		let send_objects = object::Sender::new(session.clone());
-		let recv_objects = object::Receiver::new(session.clone());
-
-		Ok(Session {
-			send_control,
-			recv_control,
-			send_objects,
-			recv_objects,
-		})
-	}
-}

moq-transport/src/session/publisher.rs

@@ -0,0 +1,234 @@
+use std::{
+	collections::{hash_map, HashMap},
+	sync::{Arc, Mutex},
+};
+
+use tokio::task::AbortHandle;
+use webtransport_quinn::Session;
+
+use crate::{
+	cache::{broadcast, segment, track, CacheError},
+	message,
+	message::Message,
+	MoqError, VarInt,
+};
+
+use super::{Control, SessionError};
+
+/// Serves broadcasts over the network, automatically handling subscriptions and caching.
+// TODO Clone specific fields when a task actually needs it.
+#[derive(Clone, Debug)]
+pub struct Publisher {
+	// A map of active subscriptions, containing an abort handle to cancel them.
+	subscribes: Arc<Mutex<HashMap<VarInt, AbortHandle>>>,
+	webtransport: Session,
+	control: Control,
+	source: broadcast::Subscriber,
+}
+
+impl Publisher {
+	pub(crate) fn new(webtransport: Session, control: Control, source: broadcast::Subscriber) -> Self {
+		Self {
+			webtransport,
+			control,
+			subscribes: Default::default(),
+			source,
+		}
+	}
+
+	// TODO Serve a broadcast without sending an ANNOUNCE.
+	// fn serve(&mut self, broadcast: broadcast::Subscriber) -> Result<(), SessionError> {
+
+	// TODO Wait until the next subscribe that doesn't route to an ANNOUNCE.
+	// pub async fn subscribed(&mut self) -> Result<track::Producer, SessionError> {
+
+	pub async fn run(mut self) -> Result<(), SessionError> {
+		let res = self.run_inner().await;
+
+		// Terminate all active subscribes on error.
+		self.subscribes
+			.lock()
+			.unwrap()
+			.drain()
+			.for_each(|(_, abort)| abort.abort());
+
+		res
+	}
+
+	pub async fn run_inner(&mut self) -> Result<(), SessionError> {
+		loop {
+			tokio::select! {
+				stream = self.webtransport.accept_uni() => {
+					stream?;
+					return Err(SessionError::RoleViolation(VarInt::ZERO));
+				}
+				// NOTE: this is not cancel safe, but it's fine since the other branchs are fatal.
+				msg = self.control.recv() => {
+					let msg = msg?;
+
+					log::info!("message received: {:?}", msg);
+					if let Err(err) = self.recv_message(&msg).await {
+						log::warn!("message error: {:?} {:?}", err, msg);
+					}
+				},
+				// No more broadcasts are available.
+				err = self.source.closed() => {
+					self.webtransport.close(err.code(), err.reason().as_bytes());
+					return Ok(());
+				},
+			}
+		}
+	}
+
+	async fn recv_message(&mut self, msg: &Message) -> Result<(), SessionError> {
+		match msg {
+			Message::AnnounceOk(msg) => self.recv_announce_ok(msg).await,
+			Message::AnnounceError(msg) => self.recv_announce_error(msg).await,
+			Message::Subscribe(msg) => self.recv_subscribe(msg).await,
+			Message::Unsubscribe(msg) => self.recv_unsubscribe(msg).await,
+			_ => Err(SessionError::RoleViolation(msg.id())),
+		}
+	}
+
+	async fn recv_announce_ok(&mut self, _msg: &message::AnnounceOk) -> Result<(), SessionError> {
+		// We didn't send an announce.
+		Err(CacheError::NotFound.into())
+	}
+
+	async fn recv_announce_error(&mut self, _msg: &message::AnnounceError) -> Result<(), SessionError> {
+		// We didn't send an announce.
+		Err(CacheError::NotFound.into())
+	}
+
+	async fn recv_subscribe(&mut self, msg: &message::Subscribe) -> Result<(), SessionError> {
+		// Assume that the subscribe ID is unique for now.
+		let abort = match self.start_subscribe(msg.clone()) {
+			Ok(abort) => abort,
+			Err(err) => return self.reset_subscribe(msg.id, err).await,
+		};
+
+		// Insert the abort handle into the lookup table.
+		match self.subscribes.lock().unwrap().entry(msg.id) {
+			hash_map::Entry::Occupied(_) => return Err(CacheError::Duplicate.into()), // TODO fatal, because we already started the task
+			hash_map::Entry::Vacant(entry) => entry.insert(abort),
+		};
+
+		self.control
+			.send(message::SubscribeOk {
+				id: msg.id,
+				expires: VarInt::ZERO,
+			})
+			.await
+	}
+
+	async fn reset_subscribe<E: MoqError>(&mut self, id: VarInt, err: E) -> Result<(), SessionError> {
+		let msg = message::SubscribeReset {
+			id,
+			code: err.code(),
+			reason: err.reason(),
+
+			// TODO properly populate these
+			// But first: https://github.com/moq-wg/moq-transport/issues/313
+			final_group: VarInt::ZERO,
+			final_object: VarInt::ZERO,
+		};
+
+		self.control.send(msg).await
+	}
+
+	fn start_subscribe(&mut self, msg: message::Subscribe) -> Result<AbortHandle, SessionError> {
+		// We currently don't use the namespace field in SUBSCRIBE
+		// Make sure the namespace is empty if it's provided.
+		if msg.namespace.as_ref().map_or(false, |namespace| !namespace.is_empty()) {
+			return Err(CacheError::NotFound.into());
+		}
+
+		let mut track = self.source.get_track(&msg.name)?;
+
+		// TODO only clone the fields we need
+		let mut this = self.clone();
+
+		let handle = tokio::spawn(async move {
+			log::info!("serving track: name={}", track.name);
+
+			let res = this.run_subscribe(msg.id, &mut track).await;
+			if let Err(err) = &res {
+				log::warn!("failed to serve track: name={} err={:#?}", track.name, err);
+			}
+
+			// Make sure we send a reset at the end.
+			let err = res.err().unwrap_or(CacheError::Closed.into());
+			this.reset_subscribe(msg.id, err).await.ok();
+
+			// We're all done, so clean up the abort handle.
+			this.subscribes.lock().unwrap().remove(&msg.id);
+		});
+
+		Ok(handle.abort_handle())
+	}
+
+	async fn run_subscribe(&self, id: VarInt, track: &mut track::Subscriber) -> Result<(), SessionError> {
+		// TODO add an Ok method to track::Publisher so we can send SUBSCRIBE_OK
+
+		while let Some(mut segment) = track.next_segment().await? {
+			// TODO only clone the fields we need
+			let this = self.clone();
+
+			tokio::spawn(async move {
+				if let Err(err) = this.run_segment(id, &mut segment).await {
+					log::warn!("failed to serve segment: {:?}", err)
+				}
+			});
+		}
+
+		Ok(())
+	}
+
+	async fn run_segment(&self, id: VarInt, segment: &mut segment::Subscriber) -> Result<(), SessionError> {
+		log::trace!("serving group: {:?}", segment);
+
+		let mut stream = self.webtransport.open_uni().await?;
+
+		// Convert the u32 to a i32, since the Quinn set_priority is signed.
+		let priority = (segment.priority as i64 - i32::MAX as i64) as i32;
+		stream.set_priority(priority).ok();
+
+		while let Some(mut fragment) = segment.next_fragment().await? {
+			let object = message::Object {
+				track: id,
+
+				// Properties of the segment
+				group: segment.sequence,
+				priority: segment.priority,
+				expires: segment.expires,
+
+				// Properties of the fragment
+				sequence: fragment.sequence,
+				size: fragment.size,
+			};
+
+			object
+				.encode(&mut stream, &self.control.ext)
+				.await
+				.map_err(|e| SessionError::Unknown(e.to_string()))?;
+
+			while let Some(chunk) = fragment.read_chunk().await? {
+				stream.write_all(&chunk).await?;
+			}
+		}
+
+		Ok(())
+	}
+
+	async fn recv_unsubscribe(&mut self, msg: &message::Unsubscribe) -> Result<(), SessionError> {
+		let abort = self
+			.subscribes
+			.lock()
+			.unwrap()
+			.remove(&msg.id)
+			.ok_or(CacheError::NotFound)?;
+		abort.abort();
+
+		self.reset_subscribe(msg.id, CacheError::Stop).await
+	}
+}

moq-transport/src/session/server.rs

@@ -0,0 +1,112 @@
+use super::{Control, Publisher, SessionError, Subscriber};
+use crate::{cache::broadcast, setup};
+
+use webtransport_quinn::{RecvStream, SendStream, Session};
+
+/// An endpoint that accepts connections, publishing and/or consuming live streams.
+pub struct Server {}
+
+impl Server {
+	/// Accept an established Webtransport session, performing the MoQ handshake.
+	///
+	/// This returns a [Request] half-way through the handshake that allows the application to accept or deny the session.
+	pub async fn accept(session: Session) -> Result<Request, SessionError> {
+		let mut control = session.accept_bi().await?;
+
+		let mut client = setup::Client::decode(&mut control.1).await?;
+
+		if client.versions.contains(&setup::Version::DRAFT_01) {
+			// We always require subscriber ID.
+			client.extensions.require_subscriber_id()?;
+
+			// We require OBJECT_EXPIRES for publishers only.
+			if client.role.is_publisher() {
+				client.extensions.require_object_expires()?;
+			}
+
+		// We don't require SUBSCRIBE_SPLIT since it's easy enough to support, but it's clearly an oversight.
+		// client.extensions.require(&Extension::SUBSCRIBE_SPLIT)?;
+		} else if client.versions.contains(&setup::Version::KIXEL_01) {
+			// Extensions didn't exist in KIXEL_01, so we set them manually.
+			client.extensions = setup::Extensions {
+				object_expires: true,
+				subscriber_id: true,
+				subscribe_split: true,
+			};
+		} else {
+			return Err(SessionError::Version(
+				client.versions,
+				[setup::Version::DRAFT_01, setup::Version::KIXEL_01].into(),
+			));
+		}
+
+		Ok(Request {
+			session,
+			client,
+			control,
+		})
+	}
+}
+
+/// A partially complete MoQ Transport handshake.
+pub struct Request {
+	session: Session,
+	client: setup::Client,
+	control: (SendStream, RecvStream),
+}
+
+impl Request {
+	/// Accept the session as a publisher, using the provided broadcast to serve subscriptions.
+	pub async fn publisher(mut self, source: broadcast::Subscriber) -> Result<Publisher, SessionError> {
+		let setup = self.setup(setup::Role::Publisher)?;
+		setup.encode(&mut self.control.0).await?;
+
+		let control = Control::new(self.control.0, self.control.1, setup.extensions);
+		let publisher = Publisher::new(self.session, control, source);
+		Ok(publisher)
+	}
+
+	/// Accept the session as a subscriber only.
+	pub async fn subscriber(mut self, source: broadcast::Publisher) -> Result<Subscriber, SessionError> {
+		let setup = self.setup(setup::Role::Subscriber)?;
+		setup.encode(&mut self.control.0).await?;
+
+		let control = Control::new(self.control.0, self.control.1, setup.extensions);
+		let subscriber = Subscriber::new(self.session, control, source);
+		Ok(subscriber)
+	}
+
+	// TODO Accept the session and perform both roles.
+	/*
+	pub async fn accept(self) -> anyhow::Result<(Publisher, Subscriber)> {
+		self.ok(setup::Role::Both).await
+	}
+	*/
+
+	fn setup(&mut self, role: setup::Role) -> Result<setup::Server, SessionError> {
+		let server = setup::Server {
+			role,
+			version: setup::Version::DRAFT_01,
+			extensions: self.client.extensions.clone(),
+			params: Default::default(),
+		};
+
+		// We need to sure we support the opposite of the client's role.
+		// ex. if the client is a publisher, we must be a subscriber ONLY.
+		if !self.client.role.is_compatible(server.role) {
+			return Err(SessionError::RoleIncompatible(self.client.role, server.role));
+		}
+
+		Ok(server)
+	}
+
+	/// Reject the request, closing the Webtransport session.
+	pub fn reject(self, code: u32) {
+		self.session.close(code, b"")
+	}
+
+	/// The role advertised by the client.
+	pub fn role(&self) -> setup::Role {
+		self.client.role
+	}
+}