/usr/share/gocode/src/github.com/bradfitz/http2/server.go is in golang-github-bradfitz-http2-dev 0.0~git20150509-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 | // Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// See https://code.google.com/p/go/source/browse/CONTRIBUTORS
// Licensed under the same terms as Go itself:
// https://code.google.com/p/go/source/browse/LICENSE
// TODO: replace all <-sc.doneServing with reads from the stream's cw
// instead, and make sure that on close we close all open
// streams. then remove doneServing?
// TODO: finish GOAWAY support. Consider each incoming frame type and
// whether it should be ignored during a shutdown race.
// TODO: disconnect idle clients. GFE seems to do 4 minutes. make
// configurable? or maximum number of idle clients and remove the
// oldest?
// TODO: turn off the serve goroutine when idle, so
// an idle conn only has the readFrames goroutine active. (which could
// also be optimized probably to pin less memory in crypto/tls). This
// would involve tracking when the serve goroutine is active (atomic
// int32 read/CAS probably?) and starting it up when frames arrive,
// and shutting it down when all handlers exit. the occasional PING
// packets could use time.AfterFunc to call sc.wakeStartServeLoop()
// (which is a no-op if already running) and then queue the PING write
// as normal. The serve loop would then exit in most cases (if no
// Handlers running) and not be woken up again until the PING packet
// returns.
// TODO (maybe): add a mechanism for Handlers to going into
// half-closed-local mode (rw.(io.Closer) test?) but not exit their
// handler, and continue to be able to read from the
// Request.Body. This would be a somewhat semantic change from HTTP/1
// (or at least what we expose in net/http), so I'd probably want to
// add it there too. For now, this package says that returning from
// the Handler ServeHTTP function means you're both done reading and
// done writing, without a way to stop just one or the other.
package http2
import (
"bufio"
"bytes"
"crypto/tls"
"errors"
"fmt"
"io"
"log"
"net"
"net/http"
"net/url"
"strconv"
"strings"
"sync"
"time"
"github.com/bradfitz/http2/hpack"
)
const (
prefaceTimeout = 10 * time.Second
firstSettingsTimeout = 2 * time.Second // should be in-flight with preface anyway
handlerChunkWriteSize = 4 << 10
defaultMaxStreams = 250 // TODO: make this 100 as the GFE seems to?
)
var (
errClientDisconnected = errors.New("client disconnected")
errClosedBody = errors.New("body closed by handler")
errStreamBroken = errors.New("http2: stream broken")
)
var responseWriterStatePool = sync.Pool{
New: func() interface{} {
rws := &responseWriterState{}
rws.bw = bufio.NewWriterSize(chunkWriter{rws}, handlerChunkWriteSize)
return rws
},
}
// Test hooks.
var (
testHookOnConn func()
testHookGetServerConn func(*serverConn)
testHookOnPanicMu *sync.Mutex // nil except in tests
testHookOnPanic func(sc *serverConn, panicVal interface{}) (rePanic bool)
)
// Server is an HTTP/2 server.
type Server struct {
// MaxHandlers limits the number of http.Handler ServeHTTP goroutines
// which may run at a time over all connections.
// Negative or zero no limit.
// TODO: implement
MaxHandlers int
// MaxConcurrentStreams optionally specifies the number of
// concurrent streams that each client may have open at a
// time. This is unrelated to the number of http.Handler goroutines
// which may be active globally, which is MaxHandlers.
// If zero, MaxConcurrentStreams defaults to at least 100, per
// the HTTP/2 spec's recommendations.
MaxConcurrentStreams uint32
// MaxReadFrameSize optionally specifies the largest frame
// this server is willing to read. A valid value is between
// 16k and 16M, inclusive. If zero or otherwise invalid, a
// default value is used.
MaxReadFrameSize uint32
// PermitProhibitedCipherSuites, if true, permits the use of
// cipher suites prohibited by the HTTP/2 spec.
PermitProhibitedCipherSuites bool
}
func (s *Server) maxReadFrameSize() uint32 {
if v := s.MaxReadFrameSize; v >= minMaxFrameSize && v <= maxFrameSize {
return v
}
return defaultMaxReadFrameSize
}
func (s *Server) maxConcurrentStreams() uint32 {
if v := s.MaxConcurrentStreams; v > 0 {
return v
}
return defaultMaxStreams
}
// ConfigureServer adds HTTP/2 support to a net/http Server.
//
// The configuration conf may be nil.
//
// ConfigureServer must be called before s begins serving.
func ConfigureServer(s *http.Server, conf *Server) {
if conf == nil {
conf = new(Server)
}
if s.TLSConfig == nil {
s.TLSConfig = new(tls.Config)
}
// Note: not setting MinVersion to tls.VersionTLS12,
// as we don't want to interfere with HTTP/1.1 traffic
// on the user's server. We enforce TLS 1.2 later once
// we accept a connection. Ideally this should be done
// during next-proto selection, but using TLS <1.2 with
// HTTP/2 is still the client's bug.
// Be sure we advertise tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
// at least.
// TODO: enable PreferServerCipherSuites?
if s.TLSConfig.CipherSuites != nil {
const requiredCipher = tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
haveRequired := false
for _, v := range s.TLSConfig.CipherSuites {
if v == requiredCipher {
haveRequired = true
break
}
}
if !haveRequired {
s.TLSConfig.CipherSuites = append(s.TLSConfig.CipherSuites, requiredCipher)
}
}
haveNPN := false
for _, p := range s.TLSConfig.NextProtos {
if p == NextProtoTLS {
haveNPN = true
break
}
}
if !haveNPN {
s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, NextProtoTLS)
}
// h2-14 is temporary (as of 2015-03-05) while we wait for all browsers
// to switch to "h2".
s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, "h2-14")
if s.TLSNextProto == nil {
s.TLSNextProto = map[string]func(*http.Server, *tls.Conn, http.Handler){}
}
protoHandler := func(hs *http.Server, c *tls.Conn, h http.Handler) {
if testHookOnConn != nil {
testHookOnConn()
}
conf.handleConn(hs, c, h)
}
s.TLSNextProto[NextProtoTLS] = protoHandler
s.TLSNextProto["h2-14"] = protoHandler // temporary; see above.
}
func (srv *Server) handleConn(hs *http.Server, c net.Conn, h http.Handler) {
sc := &serverConn{
srv: srv,
hs: hs,
conn: c,
remoteAddrStr: c.RemoteAddr().String(),
bw: newBufferedWriter(c),
handler: h,
streams: make(map[uint32]*stream),
readFrameCh: make(chan frameAndGate),
readFrameErrCh: make(chan error, 1), // must be buffered for 1
wantWriteFrameCh: make(chan frameWriteMsg, 8),
wroteFrameCh: make(chan struct{}, 1), // buffered; one send in reading goroutine
bodyReadCh: make(chan bodyReadMsg), // buffering doesn't matter either way
doneServing: make(chan struct{}),
advMaxStreams: srv.maxConcurrentStreams(),
writeSched: writeScheduler{
maxFrameSize: initialMaxFrameSize,
},
initialWindowSize: initialWindowSize,
headerTableSize: initialHeaderTableSize,
serveG: newGoroutineLock(),
pushEnabled: true,
}
sc.flow.add(initialWindowSize)
sc.inflow.add(initialWindowSize)
sc.hpackEncoder = hpack.NewEncoder(&sc.headerWriteBuf)
sc.hpackDecoder = hpack.NewDecoder(initialHeaderTableSize, sc.onNewHeaderField)
fr := NewFramer(sc.bw, c)
fr.SetMaxReadFrameSize(srv.maxReadFrameSize())
sc.framer = fr
if tc, ok := c.(*tls.Conn); ok {
sc.tlsState = new(tls.ConnectionState)
*sc.tlsState = tc.ConnectionState()
// 9.2 Use of TLS Features
// An implementation of HTTP/2 over TLS MUST use TLS
// 1.2 or higher with the restrictions on feature set
// and cipher suite described in this section. Due to
// implementation limitations, it might not be
// possible to fail TLS negotiation. An endpoint MUST
// immediately terminate an HTTP/2 connection that
// does not meet the TLS requirements described in
// this section with a connection error (Section
// 5.4.1) of type INADEQUATE_SECURITY.
if sc.tlsState.Version < tls.VersionTLS12 {
sc.rejectConn(ErrCodeInadequateSecurity, "TLS version too low")
return
}
if sc.tlsState.ServerName == "" {
// Client must use SNI, but we don't enforce that anymore,
// since it was causing problems when connecting to bare IP
// addresses during development.
//
// TODO: optionally enforce? Or enforce at the time we receive
// a new request, and verify the the ServerName matches the :authority?
// But that precludes proxy situations, perhaps.
//
// So for now, do nothing here again.
}
if !srv.PermitProhibitedCipherSuites && isBadCipher(sc.tlsState.CipherSuite) {
// "Endpoints MAY choose to generate a connection error
// (Section 5.4.1) of type INADEQUATE_SECURITY if one of
// the prohibited cipher suites are negotiated."
//
// We choose that. In my opinion, the spec is weak
// here. It also says both parties must support at least
// TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 so there's no
// excuses here. If we really must, we could allow an
// "AllowInsecureWeakCiphers" option on the server later.
// Let's see how it plays out first.
sc.rejectConn(ErrCodeInadequateSecurity, fmt.Sprintf("Prohibited TLS 1.2 Cipher Suite: %x", sc.tlsState.CipherSuite))
return
}
}
if hook := testHookGetServerConn; hook != nil {
hook(sc)
}
sc.serve()
}
// isBadCipher reports whether the cipher is blacklisted by the HTTP/2 spec.
func isBadCipher(cipher uint16) bool {
switch cipher {
case tls.TLS_RSA_WITH_RC4_128_SHA,
tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
tls.TLS_RSA_WITH_AES_128_CBC_SHA,
tls.TLS_RSA_WITH_AES_256_CBC_SHA,
tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA,
tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:
// Reject cipher suites from Appendix A.
// "This list includes those cipher suites that do not
// offer an ephemeral key exchange and those that are
// based on the TLS null, stream or block cipher type"
return true
default:
return false
}
}
func (sc *serverConn) rejectConn(err ErrCode, debug string) {
log.Printf("REJECTING conn: %v, %s", err, debug)
// ignoring errors. hanging up anyway.
sc.framer.WriteGoAway(0, err, []byte(debug))
sc.bw.Flush()
sc.conn.Close()
}
// frameAndGates coordinates the readFrames and serve
// goroutines. Because the Framer interface only permits the most
// recently-read Frame from being accessed, the readFrames goroutine
// blocks until it has a frame, passes it to serve, and then waits for
// serve to be done with it before reading the next one.
type frameAndGate struct {
f Frame
g gate
}
type serverConn struct {
// Immutable:
srv *Server
hs *http.Server
conn net.Conn
bw *bufferedWriter // writing to conn
handler http.Handler
framer *Framer
hpackDecoder *hpack.Decoder
doneServing chan struct{} // closed when serverConn.serve ends
readFrameCh chan frameAndGate // written by serverConn.readFrames
readFrameErrCh chan error
wantWriteFrameCh chan frameWriteMsg // from handlers -> serve
wroteFrameCh chan struct{} // from writeFrameAsync -> serve, tickles more frame writes
bodyReadCh chan bodyReadMsg // from handlers -> serve
testHookCh chan func() // code to run on the serve loop
flow flow // conn-wide (not stream-specific) outbound flow control
inflow flow // conn-wide inbound flow control
tlsState *tls.ConnectionState // shared by all handlers, like net/http
remoteAddrStr string
// Everything following is owned by the serve loop; use serveG.check():
serveG goroutineLock // used to verify funcs are on serve()
pushEnabled bool
sawFirstSettings bool // got the initial SETTINGS frame after the preface
needToSendSettingsAck bool
unackedSettings int // how many SETTINGS have we sent without ACKs?
clientMaxStreams uint32 // SETTINGS_MAX_CONCURRENT_STREAMS from client (our PUSH_PROMISE limit)
advMaxStreams uint32 // our SETTINGS_MAX_CONCURRENT_STREAMS advertised the client
curOpenStreams uint32 // client's number of open streams
maxStreamID uint32 // max ever seen
streams map[uint32]*stream
initialWindowSize int32
headerTableSize uint32
maxHeaderListSize uint32 // zero means unknown (default)
canonHeader map[string]string // http2-lower-case -> Go-Canonical-Case
req requestParam // non-zero while reading request headers
writingFrame bool // started write goroutine but haven't heard back on wroteFrameCh
needsFrameFlush bool // last frame write wasn't a flush
writeSched writeScheduler
inGoAway bool // we've started to or sent GOAWAY
needToSendGoAway bool // we need to schedule a GOAWAY frame write
goAwayCode ErrCode
shutdownTimerCh <-chan time.Time // nil until used
shutdownTimer *time.Timer // nil until used
// Owned by the writeFrameAsync goroutine:
headerWriteBuf bytes.Buffer
hpackEncoder *hpack.Encoder
}
// requestParam is the state of the next request, initialized over
// potentially several frames HEADERS + zero or more CONTINUATION
// frames.
type requestParam struct {
// stream is non-nil if we're reading (HEADER or CONTINUATION)
// frames for a request (but not DATA).
stream *stream
header http.Header
method, path string
scheme, authority string
sawRegularHeader bool // saw a non-pseudo header already
invalidHeader bool // an invalid header was seen
}
// stream represents a stream. This is the minimal metadata needed by
// the serve goroutine. Most of the actual stream state is owned by
// the http.Handler's goroutine in the responseWriter. Because the
// responseWriter's responseWriterState is recycled at the end of a
// handler, this struct intentionally has no pointer to the
// *responseWriter{,State} itself, as the Handler ending nils out the
// responseWriter's state field.
type stream struct {
// immutable:
id uint32
body *pipe // non-nil if expecting DATA frames
cw closeWaiter // closed wait stream transitions to closed state
// owned by serverConn's serve loop:
bodyBytes int64 // body bytes seen so far
declBodyBytes int64 // or -1 if undeclared
flow flow // limits writing from Handler to client
inflow flow // what the client is allowed to POST/etc to us
parent *stream // or nil
weight uint8
state streamState
sentReset bool // only true once detached from streams map
gotReset bool // only true once detacted from streams map
}
func (sc *serverConn) Framer() *Framer { return sc.framer }
func (sc *serverConn) CloseConn() error { return sc.conn.Close() }
func (sc *serverConn) Flush() error { return sc.bw.Flush() }
func (sc *serverConn) HeaderEncoder() (*hpack.Encoder, *bytes.Buffer) {
return sc.hpackEncoder, &sc.headerWriteBuf
}
func (sc *serverConn) state(streamID uint32) (streamState, *stream) {
sc.serveG.check()
// http://http2.github.io/http2-spec/#rfc.section.5.1
if st, ok := sc.streams[streamID]; ok {
return st.state, st
}
// "The first use of a new stream identifier implicitly closes all
// streams in the "idle" state that might have been initiated by
// that peer with a lower-valued stream identifier. For example, if
// a client sends a HEADERS frame on stream 7 without ever sending a
// frame on stream 5, then stream 5 transitions to the "closed"
// state when the first frame for stream 7 is sent or received."
if streamID <= sc.maxStreamID {
return stateClosed, nil
}
return stateIdle, nil
}
func (sc *serverConn) vlogf(format string, args ...interface{}) {
if VerboseLogs {
sc.logf(format, args...)
}
}
func (sc *serverConn) logf(format string, args ...interface{}) {
if lg := sc.hs.ErrorLog; lg != nil {
lg.Printf(format, args...)
} else {
log.Printf(format, args...)
}
}
func (sc *serverConn) condlogf(err error, format string, args ...interface{}) {
if err == nil {
return
}
str := err.Error()
if err == io.EOF || strings.Contains(str, "use of closed network connection") {
// Boring, expected errors.
sc.vlogf(format, args...)
} else {
sc.logf(format, args...)
}
}
func (sc *serverConn) onNewHeaderField(f hpack.HeaderField) {
sc.serveG.check()
sc.vlogf("got header field %+v", f)
switch {
case !validHeader(f.Name):
sc.req.invalidHeader = true
case strings.HasPrefix(f.Name, ":"):
if sc.req.sawRegularHeader {
sc.logf("pseudo-header after regular header")
sc.req.invalidHeader = true
return
}
var dst *string
switch f.Name {
case ":method":
dst = &sc.req.method
case ":path":
dst = &sc.req.path
case ":scheme":
dst = &sc.req.scheme
case ":authority":
dst = &sc.req.authority
default:
// 8.1.2.1 Pseudo-Header Fields
// "Endpoints MUST treat a request or response
// that contains undefined or invalid
// pseudo-header fields as malformed (Section
// 8.1.2.6)."
sc.logf("invalid pseudo-header %q", f.Name)
sc.req.invalidHeader = true
return
}
if *dst != "" {
sc.logf("duplicate pseudo-header %q sent", f.Name)
sc.req.invalidHeader = true
return
}
*dst = f.Value
case f.Name == "cookie":
sc.req.sawRegularHeader = true
if s, ok := sc.req.header["Cookie"]; ok && len(s) == 1 {
s[0] = s[0] + "; " + f.Value
} else {
sc.req.header.Add("Cookie", f.Value)
}
default:
sc.req.sawRegularHeader = true
sc.req.header.Add(sc.canonicalHeader(f.Name), f.Value)
}
}
func (sc *serverConn) canonicalHeader(v string) string {
sc.serveG.check()
cv, ok := commonCanonHeader[v]
if ok {
return cv
}
cv, ok = sc.canonHeader[v]
if ok {
return cv
}
if sc.canonHeader == nil {
sc.canonHeader = make(map[string]string)
}
cv = http.CanonicalHeaderKey(v)
sc.canonHeader[v] = cv
return cv
}
// readFrames is the loop that reads incoming frames.
// It's run on its own goroutine.
func (sc *serverConn) readFrames() {
g := make(gate, 1)
for {
f, err := sc.framer.ReadFrame()
if err != nil {
sc.readFrameErrCh <- err
close(sc.readFrameCh)
return
}
sc.readFrameCh <- frameAndGate{f, g}
// We can't read another frame until this one is
// processed, as the ReadFrame interface doesn't copy
// memory. The Frame accessor methods access the last
// frame's (shared) buffer. So we wait for the
// serve goroutine to tell us it's done:
g.Wait()
}
}
// writeFrameAsync runs in its own goroutine and writes a single frame
// and then reports when it's done.
// At most one goroutine can be running writeFrameAsync at a time per
// serverConn.
func (sc *serverConn) writeFrameAsync(wm frameWriteMsg) {
err := wm.write.writeFrame(sc)
if ch := wm.done; ch != nil {
select {
case ch <- err:
default:
panic(fmt.Sprintf("unbuffered done channel passed in for type %T", wm.write))
}
}
sc.wroteFrameCh <- struct{}{} // tickle frame selection scheduler
}
func (sc *serverConn) closeAllStreamsOnConnClose() {
sc.serveG.check()
for _, st := range sc.streams {
sc.closeStream(st, errClientDisconnected)
}
}
func (sc *serverConn) stopShutdownTimer() {
sc.serveG.check()
if t := sc.shutdownTimer; t != nil {
t.Stop()
}
}
func (sc *serverConn) notePanic() {
if testHookOnPanicMu != nil {
testHookOnPanicMu.Lock()
defer testHookOnPanicMu.Unlock()
}
if testHookOnPanic != nil {
if e := recover(); e != nil {
if testHookOnPanic(sc, e) {
panic(e)
}
}
}
}
func (sc *serverConn) serve() {
sc.serveG.check()
defer sc.notePanic()
defer sc.conn.Close()
defer sc.closeAllStreamsOnConnClose()
defer sc.stopShutdownTimer()
defer close(sc.doneServing) // unblocks handlers trying to send
sc.vlogf("HTTP/2 connection from %v on %p", sc.conn.RemoteAddr(), sc.hs)
sc.writeFrame(frameWriteMsg{
write: writeSettings{
{SettingMaxFrameSize, sc.srv.maxReadFrameSize()},
{SettingMaxConcurrentStreams, sc.advMaxStreams},
// TODO: more actual settings, notably
// SettingInitialWindowSize, but then we also
// want to bump up the conn window size the
// same amount here right after the settings
},
})
sc.unackedSettings++
if err := sc.readPreface(); err != nil {
sc.condlogf(err, "error reading preface from client %v: %v", sc.conn.RemoteAddr(), err)
return
}
go sc.readFrames() // closed by defer sc.conn.Close above
settingsTimer := time.NewTimer(firstSettingsTimeout)
for {
select {
case wm := <-sc.wantWriteFrameCh:
sc.writeFrame(wm)
case <-sc.wroteFrameCh:
if sc.writingFrame != true {
panic("internal error: expected to be already writing a frame")
}
sc.writingFrame = false
sc.scheduleFrameWrite()
case fg, ok := <-sc.readFrameCh:
if !ok {
sc.readFrameCh = nil
}
if !sc.processFrameFromReader(fg, ok) {
return
}
if settingsTimer.C != nil {
settingsTimer.Stop()
settingsTimer.C = nil
}
case m := <-sc.bodyReadCh:
sc.noteBodyRead(m.st, m.n)
case <-settingsTimer.C:
sc.logf("timeout waiting for SETTINGS frames from %v", sc.conn.RemoteAddr())
return
case <-sc.shutdownTimerCh:
sc.vlogf("GOAWAY close timer fired; closing conn from %v", sc.conn.RemoteAddr())
return
case fn := <-sc.testHookCh:
fn()
}
}
}
// readPreface reads the ClientPreface greeting from the peer
// or returns an error on timeout or an invalid greeting.
func (sc *serverConn) readPreface() error {
errc := make(chan error, 1)
go func() {
// Read the client preface
buf := make([]byte, len(ClientPreface))
if _, err := io.ReadFull(sc.conn, buf); err != nil {
errc <- err
} else if !bytes.Equal(buf, clientPreface) {
errc <- fmt.Errorf("bogus greeting %q", buf)
} else {
errc <- nil
}
}()
timer := time.NewTimer(prefaceTimeout) // TODO: configurable on *Server?
defer timer.Stop()
select {
case <-timer.C:
return errors.New("timeout waiting for client preface")
case err := <-errc:
if err == nil {
sc.vlogf("client %v said hello", sc.conn.RemoteAddr())
}
return err
}
}
// writeDataFromHandler writes the data described in req to stream.id.
//
// The provided ch is used to avoid allocating new channels for each
// write operation. It's expected that the caller reuses writeData and ch
// over time.
//
// The flow control currently happens in the Handler where it waits
// for 1 or more bytes to be available to then write here. So at this
// point we know that we have flow control. But this might have to
// change when priority is implemented, so the serve goroutine knows
// the total amount of bytes waiting to be sent and can can have more
// scheduling decisions available.
func (sc *serverConn) writeDataFromHandler(stream *stream, writeData *writeData, ch chan error) error {
sc.writeFrameFromHandler(frameWriteMsg{
write: writeData,
stream: stream,
done: ch,
})
select {
case err := <-ch:
return err
case <-sc.doneServing:
return errClientDisconnected
case <-stream.cw:
return errStreamBroken
}
}
// writeFrameFromHandler sends wm to sc.wantWriteFrameCh, but aborts
// if the connection has gone away.
//
// This must not be run from the serve goroutine itself, else it might
// deadlock writing to sc.wantWriteFrameCh (which is only mildly
// buffered and is read by serve itself). If you're on the serve
// goroutine, call writeFrame instead.
func (sc *serverConn) writeFrameFromHandler(wm frameWriteMsg) {
sc.serveG.checkNotOn() // NOT
select {
case sc.wantWriteFrameCh <- wm:
case <-sc.doneServing:
// Client has closed their connection to the server.
}
}
// writeFrame schedules a frame to write and sends it if there's nothing
// already being written.
//
// There is no pushback here (the serve goroutine never blocks). It's
// the http.Handlers that block, waiting for their previous frames to
// make it onto the wire
//
// If you're not on the serve goroutine, use writeFrameFromHandler instead.
func (sc *serverConn) writeFrame(wm frameWriteMsg) {
sc.serveG.check()
sc.writeSched.add(wm)
sc.scheduleFrameWrite()
}
// startFrameWrite starts a goroutine to write wm (in a separate
// goroutine since that might block on the network), and updates the
// serve goroutine's state about the world, updated from info in wm.
func (sc *serverConn) startFrameWrite(wm frameWriteMsg) {
sc.serveG.check()
if sc.writingFrame {
panic("internal error: can only be writing one frame at a time")
}
sc.writingFrame = true
st := wm.stream
if st != nil {
switch st.state {
case stateHalfClosedLocal:
panic("internal error: attempt to send frame on half-closed-local stream")
case stateClosed:
if st.sentReset || st.gotReset {
// Skip this frame. But fake the frame write to reschedule:
sc.wroteFrameCh <- struct{}{}
return
}
panic(fmt.Sprintf("internal error: attempt to send a write %v on a closed stream", wm))
}
}
sc.needsFrameFlush = true
if endsStream(wm.write) {
if st == nil {
panic("internal error: expecting non-nil stream")
}
switch st.state {
case stateOpen:
// Here we would go to stateHalfClosedLocal in
// theory, but since our handler is done and
// the net/http package provides no mechanism
// for finishing writing to a ResponseWriter
// while still reading data (see possible TODO
// at top of this file), we go into closed
// state here anyway, after telling the peer
// we're hanging up on them.
st.state = stateHalfClosedLocal // won't last long, but necessary for closeStream via resetStream
errCancel := StreamError{st.id, ErrCodeCancel}
sc.resetStream(errCancel)
case stateHalfClosedRemote:
sc.closeStream(st, nil)
}
}
go sc.writeFrameAsync(wm)
}
// scheduleFrameWrite tickles the frame writing scheduler.
//
// If a frame is already being written, nothing happens. This will be called again
// when the frame is done being written.
//
// If a frame isn't being written we need to send one, the best frame
// to send is selected, preferring first things that aren't
// stream-specific (e.g. ACKing settings), and then finding the
// highest priority stream.
//
// If a frame isn't being written and there's nothing else to send, we
// flush the write buffer.
func (sc *serverConn) scheduleFrameWrite() {
sc.serveG.check()
if sc.writingFrame {
return
}
if sc.needToSendGoAway {
sc.needToSendGoAway = false
sc.startFrameWrite(frameWriteMsg{
write: &writeGoAway{
maxStreamID: sc.maxStreamID,
code: sc.goAwayCode,
},
})
return
}
if sc.needToSendSettingsAck {
sc.needToSendSettingsAck = false
sc.startFrameWrite(frameWriteMsg{write: writeSettingsAck{}})
return
}
if !sc.inGoAway {
if wm, ok := sc.writeSched.take(); ok {
sc.startFrameWrite(wm)
return
}
}
if sc.needsFrameFlush {
sc.startFrameWrite(frameWriteMsg{write: flushFrameWriter{}})
sc.needsFrameFlush = false // after startFrameWrite, since it sets this true
return
}
}
func (sc *serverConn) goAway(code ErrCode) {
sc.serveG.check()
if sc.inGoAway {
return
}
if code != ErrCodeNo {
sc.shutDownIn(250 * time.Millisecond)
} else {
// TODO: configurable
sc.shutDownIn(1 * time.Second)
}
sc.inGoAway = true
sc.needToSendGoAway = true
sc.goAwayCode = code
sc.scheduleFrameWrite()
}
func (sc *serverConn) shutDownIn(d time.Duration) {
sc.serveG.check()
sc.shutdownTimer = time.NewTimer(d)
sc.shutdownTimerCh = sc.shutdownTimer.C
}
func (sc *serverConn) resetStream(se StreamError) {
sc.serveG.check()
sc.writeFrame(frameWriteMsg{write: se})
if st, ok := sc.streams[se.StreamID]; ok {
st.sentReset = true
sc.closeStream(st, se)
}
}
// curHeaderStreamID returns the stream ID of the header block we're
// currently in the middle of reading. If this returns non-zero, the
// next frame must be a CONTINUATION with this stream id.
func (sc *serverConn) curHeaderStreamID() uint32 {
sc.serveG.check()
st := sc.req.stream
if st == nil {
return 0
}
return st.id
}
// processFrameFromReader processes the serve loop's read from readFrameCh from the
// frame-reading goroutine.
// processFrameFromReader returns whether the connection should be kept open.
func (sc *serverConn) processFrameFromReader(fg frameAndGate, fgValid bool) bool {
sc.serveG.check()
var clientGone bool
var err error
if !fgValid {
err = <-sc.readFrameErrCh
if err == ErrFrameTooLarge {
sc.goAway(ErrCodeFrameSize)
return true // goAway will close the loop
}
clientGone = err == io.EOF || strings.Contains(err.Error(), "use of closed network connection")
if clientGone {
// TODO: could we also get into this state if
// the peer does a half close
// (e.g. CloseWrite) because they're done
// sending frames but they're still wanting
// our open replies? Investigate.
// TODO: add CloseWrite to crypto/tls.Conn first
// so we have a way to test this? I suppose
// just for testing we could have a non-TLS mode.
return false
}
}
if fgValid {
f := fg.f
sc.vlogf("got %v: %#v", f.Header(), f)
err = sc.processFrame(f)
fg.g.Done() // unblock the readFrames goroutine
if err == nil {
return true
}
}
switch ev := err.(type) {
case StreamError:
sc.resetStream(ev)
return true
case goAwayFlowError:
sc.goAway(ErrCodeFlowControl)
return true
case ConnectionError:
sc.logf("%v: %v", sc.conn.RemoteAddr(), ev)
sc.goAway(ErrCode(ev))
return true // goAway will handle shutdown
default:
if !fgValid {
sc.logf("disconnecting; error reading frame from client %s: %v", sc.conn.RemoteAddr(), err)
} else {
sc.logf("disconnection due to other error: %v", err)
}
}
return false
}
func (sc *serverConn) processFrame(f Frame) error {
sc.serveG.check()
// First frame received must be SETTINGS.
if !sc.sawFirstSettings {
if _, ok := f.(*SettingsFrame); !ok {
return ConnectionError(ErrCodeProtocol)
}
sc.sawFirstSettings = true
}
if s := sc.curHeaderStreamID(); s != 0 {
if cf, ok := f.(*ContinuationFrame); !ok {
return ConnectionError(ErrCodeProtocol)
} else if cf.Header().StreamID != s {
return ConnectionError(ErrCodeProtocol)
}
}
switch f := f.(type) {
case *SettingsFrame:
return sc.processSettings(f)
case *HeadersFrame:
return sc.processHeaders(f)
case *ContinuationFrame:
return sc.processContinuation(f)
case *WindowUpdateFrame:
return sc.processWindowUpdate(f)
case *PingFrame:
return sc.processPing(f)
case *DataFrame:
return sc.processData(f)
case *RSTStreamFrame:
return sc.processResetStream(f)
case *PriorityFrame:
return sc.processPriority(f)
case *PushPromiseFrame:
// A client cannot push. Thus, servers MUST treat the receipt of a PUSH_PROMISE
// frame as a connection error (Section 5.4.1) of type PROTOCOL_ERROR.
return ConnectionError(ErrCodeProtocol)
default:
log.Printf("Ignoring frame: %v", f.Header())
return nil
}
}
func (sc *serverConn) processPing(f *PingFrame) error {
sc.serveG.check()
if f.Flags.Has(FlagSettingsAck) {
// 6.7 PING: " An endpoint MUST NOT respond to PING frames
// containing this flag."
return nil
}
if f.StreamID != 0 {
// "PING frames are not associated with any individual
// stream. If a PING frame is received with a stream
// identifier field value other than 0x0, the recipient MUST
// respond with a connection error (Section 5.4.1) of type
// PROTOCOL_ERROR."
return ConnectionError(ErrCodeProtocol)
}
sc.writeFrame(frameWriteMsg{write: writePingAck{f}})
return nil
}
func (sc *serverConn) processWindowUpdate(f *WindowUpdateFrame) error {
sc.serveG.check()
switch {
case f.StreamID != 0: // stream-level flow control
st := sc.streams[f.StreamID]
if st == nil {
// "WINDOW_UPDATE can be sent by a peer that has sent a
// frame bearing the END_STREAM flag. This means that a
// receiver could receive a WINDOW_UPDATE frame on a "half
// closed (remote)" or "closed" stream. A receiver MUST
// NOT treat this as an error, see Section 5.1."
return nil
}
if !st.flow.add(int32(f.Increment)) {
return StreamError{f.StreamID, ErrCodeFlowControl}
}
default: // connection-level flow control
if !sc.flow.add(int32(f.Increment)) {
return goAwayFlowError{}
}
}
sc.scheduleFrameWrite()
return nil
}
func (sc *serverConn) processResetStream(f *RSTStreamFrame) error {
sc.serveG.check()
state, st := sc.state(f.StreamID)
if state == stateIdle {
// 6.4 "RST_STREAM frames MUST NOT be sent for a
// stream in the "idle" state. If a RST_STREAM frame
// identifying an idle stream is received, the
// recipient MUST treat this as a connection error
// (Section 5.4.1) of type PROTOCOL_ERROR.
return ConnectionError(ErrCodeProtocol)
}
if st != nil {
st.gotReset = true
sc.closeStream(st, StreamError{f.StreamID, f.ErrCode})
}
return nil
}
func (sc *serverConn) closeStream(st *stream, err error) {
sc.serveG.check()
if st.state == stateIdle || st.state == stateClosed {
panic(fmt.Sprintf("invariant; can't close stream in state %v", st.state))
}
st.state = stateClosed
sc.curOpenStreams--
delete(sc.streams, st.id)
if p := st.body; p != nil {
p.Close(err)
}
st.cw.Close() // signals Handler's CloseNotifier, unblocks writes, etc
sc.writeSched.forgetStream(st.id)
}
func (sc *serverConn) processSettings(f *SettingsFrame) error {
sc.serveG.check()
if f.IsAck() {
sc.unackedSettings--
if sc.unackedSettings < 0 {
// Why is the peer ACKing settings we never sent?
// The spec doesn't mention this case, but
// hang up on them anyway.
return ConnectionError(ErrCodeProtocol)
}
return nil
}
if err := f.ForeachSetting(sc.processSetting); err != nil {
return err
}
sc.needToSendSettingsAck = true
sc.scheduleFrameWrite()
return nil
}
func (sc *serverConn) processSetting(s Setting) error {
sc.serveG.check()
if err := s.Valid(); err != nil {
return err
}
sc.vlogf("processing setting %v", s)
switch s.ID {
case SettingHeaderTableSize:
sc.headerTableSize = s.Val
sc.hpackEncoder.SetMaxDynamicTableSize(s.Val)
case SettingEnablePush:
sc.pushEnabled = s.Val != 0
case SettingMaxConcurrentStreams:
sc.clientMaxStreams = s.Val
case SettingInitialWindowSize:
return sc.processSettingInitialWindowSize(s.Val)
case SettingMaxFrameSize:
sc.writeSched.maxFrameSize = s.Val
case SettingMaxHeaderListSize:
sc.maxHeaderListSize = s.Val
default:
// Unknown setting: "An endpoint that receives a SETTINGS
// frame with any unknown or unsupported identifier MUST
// ignore that setting."
}
return nil
}
func (sc *serverConn) processSettingInitialWindowSize(val uint32) error {
sc.serveG.check()
// Note: val already validated to be within range by
// processSetting's Valid call.
// "A SETTINGS frame can alter the initial flow control window
// size for all current streams. When the value of
// SETTINGS_INITIAL_WINDOW_SIZE changes, a receiver MUST
// adjust the size of all stream flow control windows that it
// maintains by the difference between the new value and the
// old value."
old := sc.initialWindowSize
sc.initialWindowSize = int32(val)
growth := sc.initialWindowSize - old // may be negative
for _, st := range sc.streams {
if !st.flow.add(growth) {
// 6.9.2 Initial Flow Control Window Size
// "An endpoint MUST treat a change to
// SETTINGS_INITIAL_WINDOW_SIZE that causes any flow
// control window to exceed the maximum size as a
// connection error (Section 5.4.1) of type
// FLOW_CONTROL_ERROR."
return ConnectionError(ErrCodeFlowControl)
}
}
return nil
}
func (sc *serverConn) processData(f *DataFrame) error {
sc.serveG.check()
// "If a DATA frame is received whose stream is not in "open"
// or "half closed (local)" state, the recipient MUST respond
// with a stream error (Section 5.4.2) of type STREAM_CLOSED."
id := f.Header().StreamID
st, ok := sc.streams[id]
if !ok || st.state != stateOpen {
// This includes sending a RST_STREAM if the stream is
// in stateHalfClosedLocal (which currently means that
// the http.Handler returned, so it's done reading &
// done writing). Try to stop the client from sending
// more DATA.
return StreamError{id, ErrCodeStreamClosed}
}
if st.body == nil {
panic("internal error: should have a body in this state")
}
data := f.Data()
// Sender sending more than they'd declared?
if st.declBodyBytes != -1 && st.bodyBytes+int64(len(data)) > st.declBodyBytes {
st.body.Close(fmt.Errorf("sender tried to send more than declared Content-Length of %d bytes", st.declBodyBytes))
return StreamError{id, ErrCodeStreamClosed}
}
if len(data) > 0 {
// Check whether the client has flow control quota.
if int(st.inflow.available()) < len(data) {
return StreamError{id, ErrCodeFlowControl}
}
st.inflow.take(int32(len(data)))
wrote, err := st.body.Write(data)
if err != nil {
return StreamError{id, ErrCodeStreamClosed}
}
if wrote != len(data) {
panic("internal error: bad Writer")
}
st.bodyBytes += int64(len(data))
}
if f.StreamEnded() {
if st.declBodyBytes != -1 && st.declBodyBytes != st.bodyBytes {
st.body.Close(fmt.Errorf("request declared a Content-Length of %d but only wrote %d bytes",
st.declBodyBytes, st.bodyBytes))
} else {
st.body.Close(io.EOF)
}
st.state = stateHalfClosedRemote
}
return nil
}
func (sc *serverConn) processHeaders(f *HeadersFrame) error {
sc.serveG.check()
id := f.Header().StreamID
if sc.inGoAway {
// Ignore.
return nil
}
// http://http2.github.io/http2-spec/#rfc.section.5.1.1
if id%2 != 1 || id <= sc.maxStreamID || sc.req.stream != nil {
// Streams initiated by a client MUST use odd-numbered
// stream identifiers. [...] The identifier of a newly
// established stream MUST be numerically greater than all
// streams that the initiating endpoint has opened or
// reserved. [...] An endpoint that receives an unexpected
// stream identifier MUST respond with a connection error
// (Section 5.4.1) of type PROTOCOL_ERROR.
return ConnectionError(ErrCodeProtocol)
}
if id > sc.maxStreamID {
sc.maxStreamID = id
}
st := &stream{
id: id,
state: stateOpen,
}
if f.StreamEnded() {
st.state = stateHalfClosedRemote
}
st.cw.Init()
st.flow.conn = &sc.flow // link to conn-level counter
st.flow.add(sc.initialWindowSize)
st.inflow.conn = &sc.inflow // link to conn-level counter
st.inflow.add(initialWindowSize) // TODO: update this when we send a higher initial window size in the initial settings
sc.streams[id] = st
if f.HasPriority() {
adjustStreamPriority(sc.streams, st.id, f.Priority)
}
sc.curOpenStreams++
sc.req = requestParam{
stream: st,
header: make(http.Header),
}
return sc.processHeaderBlockFragment(st, f.HeaderBlockFragment(), f.HeadersEnded())
}
func (sc *serverConn) processContinuation(f *ContinuationFrame) error {
sc.serveG.check()
st := sc.streams[f.Header().StreamID]
if st == nil || sc.curHeaderStreamID() != st.id {
return ConnectionError(ErrCodeProtocol)
}
return sc.processHeaderBlockFragment(st, f.HeaderBlockFragment(), f.HeadersEnded())
}
func (sc *serverConn) processHeaderBlockFragment(st *stream, frag []byte, end bool) error {
sc.serveG.check()
if _, err := sc.hpackDecoder.Write(frag); err != nil {
// TODO: convert to stream error I assume?
return err
}
if !end {
return nil
}
if err := sc.hpackDecoder.Close(); err != nil {
// TODO: convert to stream error I assume?
return err
}
defer sc.resetPendingRequest()
if sc.curOpenStreams > sc.advMaxStreams {
// "Endpoints MUST NOT exceed the limit set by their
// peer. An endpoint that receives a HEADERS frame
// that causes their advertised concurrent stream
// limit to be exceeded MUST treat this as a stream
// error (Section 5.4.2) of type PROTOCOL_ERROR or
// REFUSED_STREAM."
if sc.unackedSettings == 0 {
// They should know better.
return StreamError{st.id, ErrCodeProtocol}
}
// Assume it's a network race, where they just haven't
// received our last SETTINGS update. But actually
// this can't happen yet, because we don't yet provide
// a way for users to adjust server parameters at
// runtime.
return StreamError{st.id, ErrCodeRefusedStream}
}
rw, req, err := sc.newWriterAndRequest()
if err != nil {
return err
}
st.body = req.Body.(*requestBody).pipe // may be nil
st.declBodyBytes = req.ContentLength
go sc.runHandler(rw, req)
return nil
}
func (sc *serverConn) processPriority(f *PriorityFrame) error {
adjustStreamPriority(sc.streams, f.StreamID, f.PriorityParam)
return nil
}
func adjustStreamPriority(streams map[uint32]*stream, streamID uint32, priority PriorityParam) {
st, ok := streams[streamID]
if !ok {
// TODO: not quite correct (this streamID might
// already exist in the dep tree, but be closed), but
// close enough for now.
return
}
st.weight = priority.Weight
parent := streams[priority.StreamDep] // might be nil
if parent == st {
// if client tries to set this stream to be the parent of itself
// ignore and keep going
return
}
// section 5.3.3: If a stream is made dependent on one of its
// own dependencies, the formerly dependent stream is first
// moved to be dependent on the reprioritized stream's previous
// parent. The moved dependency retains its weight.
for piter := parent; piter != nil; piter = piter.parent {
if piter == st {
parent.parent = st.parent
break
}
}
st.parent = parent
if priority.Exclusive && (st.parent != nil || priority.StreamDep == 0) {
for _, openStream := range streams {
if openStream != st && openStream.parent == st.parent {
openStream.parent = st
}
}
}
}
// resetPendingRequest zeros out all state related to a HEADERS frame
// and its zero or more CONTINUATION frames sent to start a new
// request.
func (sc *serverConn) resetPendingRequest() {
sc.serveG.check()
sc.req = requestParam{}
}
func (sc *serverConn) newWriterAndRequest() (*responseWriter, *http.Request, error) {
sc.serveG.check()
rp := &sc.req
if rp.invalidHeader || rp.method == "" || rp.path == "" ||
(rp.scheme != "https" && rp.scheme != "http") {
// See 8.1.2.6 Malformed Requests and Responses:
//
// Malformed requests or responses that are detected
// MUST be treated as a stream error (Section 5.4.2)
// of type PROTOCOL_ERROR."
//
// 8.1.2.3 Request Pseudo-Header Fields
// "All HTTP/2 requests MUST include exactly one valid
// value for the :method, :scheme, and :path
// pseudo-header fields"
return nil, nil, StreamError{rp.stream.id, ErrCodeProtocol}
}
var tlsState *tls.ConnectionState // nil if not scheme https
if rp.scheme == "https" {
tlsState = sc.tlsState
}
authority := rp.authority
if authority == "" {
authority = rp.header.Get("Host")
}
needsContinue := rp.header.Get("Expect") == "100-continue"
if needsContinue {
rp.header.Del("Expect")
}
bodyOpen := rp.stream.state == stateOpen
body := &requestBody{
conn: sc,
stream: rp.stream,
needsContinue: needsContinue,
}
// TODO: handle asterisk '*' requests + test
url, err := url.ParseRequestURI(rp.path)
if err != nil {
// TODO: find the right error code?
return nil, nil, StreamError{rp.stream.id, ErrCodeProtocol}
}
req := &http.Request{
Method: rp.method,
URL: url,
RemoteAddr: sc.remoteAddrStr,
Header: rp.header,
RequestURI: rp.path,
Proto: "HTTP/2.0",
ProtoMajor: 2,
ProtoMinor: 0,
TLS: tlsState,
Host: authority,
Body: body,
}
if bodyOpen {
body.pipe = &pipe{
b: buffer{buf: make([]byte, initialWindowSize)}, // TODO: share/remove XXX
}
body.pipe.c.L = &body.pipe.m
if vv, ok := rp.header["Content-Length"]; ok {
req.ContentLength, _ = strconv.ParseInt(vv[0], 10, 64)
} else {
req.ContentLength = -1
}
}
rws := responseWriterStatePool.Get().(*responseWriterState)
bwSave := rws.bw
*rws = responseWriterState{} // zero all the fields
rws.conn = sc
rws.bw = bwSave
rws.bw.Reset(chunkWriter{rws})
rws.stream = rp.stream
rws.req = req
rws.body = body
rws.frameWriteCh = make(chan error, 1)
rw := &responseWriter{rws: rws}
return rw, req, nil
}
// Run on its own goroutine.
func (sc *serverConn) runHandler(rw *responseWriter, req *http.Request) {
defer rw.handlerDone()
// TODO: catch panics like net/http.Server
sc.handler.ServeHTTP(rw, req)
}
// called from handler goroutines.
// h may be nil.
func (sc *serverConn) writeHeaders(st *stream, headerData *writeResHeaders, tempCh chan error) {
sc.serveG.checkNotOn() // NOT on
var errc chan error
if headerData.h != nil {
// If there's a header map (which we don't own), so we have to block on
// waiting for this frame to be written, so an http.Flush mid-handler
// writes out the correct value of keys, before a handler later potentially
// mutates it.
errc = tempCh
}
sc.writeFrameFromHandler(frameWriteMsg{
write: headerData,
stream: st,
done: errc,
})
if errc != nil {
select {
case <-errc:
// Ignore. Just for synchronization.
// Any error will be handled in the writing goroutine.
case <-sc.doneServing:
// Client has closed the connection.
}
}
}
// called from handler goroutines.
func (sc *serverConn) write100ContinueHeaders(st *stream) {
sc.writeFrameFromHandler(frameWriteMsg{
write: write100ContinueHeadersFrame{st.id},
stream: st,
})
}
// A bodyReadMsg tells the server loop that the http.Handler read n
// bytes of the DATA from the client on the given stream.
type bodyReadMsg struct {
st *stream
n int
}
// called from handler goroutines.
// Notes that the handler for the given stream ID read n bytes of its body
// and schedules flow control tokens to be sent.
func (sc *serverConn) noteBodyReadFromHandler(st *stream, n int) {
sc.serveG.checkNotOn() // NOT on
sc.bodyReadCh <- bodyReadMsg{st, n}
}
func (sc *serverConn) noteBodyRead(st *stream, n int) {
sc.serveG.check()
sc.sendWindowUpdate(nil, n) // conn-level
if st.state != stateHalfClosedRemote && st.state != stateClosed {
// Don't send this WINDOW_UPDATE if the stream is closed
// remotely.
sc.sendWindowUpdate(st, n)
}
}
// st may be nil for conn-level
func (sc *serverConn) sendWindowUpdate(st *stream, n int) {
sc.serveG.check()
// "The legal range for the increment to the flow control
// window is 1 to 2^31-1 (2,147,483,647) octets."
// A Go Read call on 64-bit machines could in theory read
// a larger Read than this. Very unlikely, but we handle it here
// rather than elsewhere for now.
const maxUint31 = 1<<31 - 1
for n >= maxUint31 {
sc.sendWindowUpdate32(st, maxUint31)
n -= maxUint31
}
sc.sendWindowUpdate32(st, int32(n))
}
// st may be nil for conn-level
func (sc *serverConn) sendWindowUpdate32(st *stream, n int32) {
sc.serveG.check()
if n == 0 {
return
}
if n < 0 {
panic("negative update")
}
var streamID uint32
if st != nil {
streamID = st.id
}
sc.writeFrame(frameWriteMsg{
write: writeWindowUpdate{streamID: streamID, n: uint32(n)},
stream: st,
})
var ok bool
if st == nil {
ok = sc.inflow.add(n)
} else {
ok = st.inflow.add(n)
}
if !ok {
panic("internal error; sent too many window updates without decrements?")
}
}
type requestBody struct {
stream *stream
conn *serverConn
closed bool
pipe *pipe // non-nil if we have a HTTP entity message body
needsContinue bool // need to send a 100-continue
}
func (b *requestBody) Close() error {
if b.pipe != nil {
b.pipe.Close(errClosedBody)
}
b.closed = true
return nil
}
func (b *requestBody) Read(p []byte) (n int, err error) {
if b.needsContinue {
b.needsContinue = false
b.conn.write100ContinueHeaders(b.stream)
}
if b.pipe == nil {
return 0, io.EOF
}
n, err = b.pipe.Read(p)
if n > 0 {
b.conn.noteBodyReadFromHandler(b.stream, n)
}
return
}
// responseWriter is the http.ResponseWriter implementation. It's
// intentionally small (1 pointer wide) to minimize garbage. The
// responseWriterState pointer inside is zeroed at the end of a
// request (in handlerDone) and calls on the responseWriter thereafter
// simply crash (caller's mistake), but the much larger responseWriterState
// and buffers are reused between multiple requests.
type responseWriter struct {
rws *responseWriterState
}
// Optional http.ResponseWriter interfaces implemented.
var (
_ http.CloseNotifier = (*responseWriter)(nil)
_ http.Flusher = (*responseWriter)(nil)
_ stringWriter = (*responseWriter)(nil)
)
type responseWriterState struct {
// immutable within a request:
stream *stream
req *http.Request
body *requestBody // to close at end of request, if DATA frames didn't
conn *serverConn
// TODO: adjust buffer writing sizes based on server config, frame size updates from peer, etc
bw *bufio.Writer // writing to a chunkWriter{this *responseWriterState}
// mutated by http.Handler goroutine:
handlerHeader http.Header // nil until called
snapHeader http.Header // snapshot of handlerHeader at WriteHeader time
status int // status code passed to WriteHeader
wroteHeader bool // WriteHeader called (explicitly or implicitly). Not necessarily sent to user yet.
sentHeader bool // have we sent the header frame?
handlerDone bool // handler has finished
curWrite writeData
frameWriteCh chan error // re-used whenever we need to block on a frame being written
closeNotifierMu sync.Mutex // guards closeNotifierCh
closeNotifierCh chan bool // nil until first used
}
type chunkWriter struct{ rws *responseWriterState }
func (cw chunkWriter) Write(p []byte) (n int, err error) { return cw.rws.writeChunk(p) }
// writeChunk writes chunks from the bufio.Writer. But because
// bufio.Writer may bypass its chunking, sometimes p may be
// arbitrarily large.
//
// writeChunk is also responsible (on the first chunk) for sending the
// HEADER response.
func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
if !rws.wroteHeader {
rws.writeHeader(200)
}
if !rws.sentHeader {
rws.sentHeader = true
var ctype, clen string // implicit ones, if we can calculate it
if rws.handlerDone && rws.snapHeader.Get("Content-Length") == "" {
clen = strconv.Itoa(len(p))
}
if rws.snapHeader.Get("Content-Type") == "" {
ctype = http.DetectContentType(p)
}
endStream := rws.handlerDone && len(p) == 0
rws.conn.writeHeaders(rws.stream, &writeResHeaders{
streamID: rws.stream.id,
httpResCode: rws.status,
h: rws.snapHeader,
endStream: endStream,
contentType: ctype,
contentLength: clen,
}, rws.frameWriteCh)
if endStream {
return 0, nil
}
}
if len(p) == 0 && !rws.handlerDone {
return 0, nil
}
curWrite := &rws.curWrite
curWrite.streamID = rws.stream.id
curWrite.p = p
curWrite.endStream = rws.handlerDone
if err := rws.conn.writeDataFromHandler(rws.stream, curWrite, rws.frameWriteCh); err != nil {
return 0, err
}
return len(p), nil
}
func (w *responseWriter) Flush() {
rws := w.rws
if rws == nil {
panic("Header called after Handler finished")
}
if rws.bw.Buffered() > 0 {
if err := rws.bw.Flush(); err != nil {
// Ignore the error. The frame writer already knows.
return
}
} else {
// The bufio.Writer won't call chunkWriter.Write
// (writeChunk with zero bytes, so we have to do it
// ourselves to force the HTTP response header and/or
// final DATA frame (with END_STREAM) to be sent.
rws.writeChunk(nil)
}
}
func (w *responseWriter) CloseNotify() <-chan bool {
rws := w.rws
if rws == nil {
panic("CloseNotify called after Handler finished")
}
rws.closeNotifierMu.Lock()
ch := rws.closeNotifierCh
if ch == nil {
ch = make(chan bool, 1)
rws.closeNotifierCh = ch
go func() {
rws.stream.cw.Wait() // wait for close
ch <- true
}()
}
rws.closeNotifierMu.Unlock()
return ch
}
func (w *responseWriter) Header() http.Header {
rws := w.rws
if rws == nil {
panic("Header called after Handler finished")
}
if rws.handlerHeader == nil {
rws.handlerHeader = make(http.Header)
}
return rws.handlerHeader
}
func (w *responseWriter) WriteHeader(code int) {
rws := w.rws
if rws == nil {
panic("WriteHeader called after Handler finished")
}
rws.writeHeader(code)
}
func (rws *responseWriterState) writeHeader(code int) {
if !rws.wroteHeader {
rws.wroteHeader = true
rws.status = code
if len(rws.handlerHeader) > 0 {
rws.snapHeader = cloneHeader(rws.handlerHeader)
}
}
}
func cloneHeader(h http.Header) http.Header {
h2 := make(http.Header, len(h))
for k, vv := range h {
vv2 := make([]string, len(vv))
copy(vv2, vv)
h2[k] = vv2
}
return h2
}
// The Life Of A Write is like this:
//
// * Handler calls w.Write or w.WriteString ->
// * -> rws.bw (*bufio.Writer) ->
// * (Handler migth call Flush)
// * -> chunkWriter{rws}
// * -> responseWriterState.writeChunk(p []byte)
// * -> responseWriterState.writeChunk (most of the magic; see comment there)
func (w *responseWriter) Write(p []byte) (n int, err error) {
return w.write(len(p), p, "")
}
func (w *responseWriter) WriteString(s string) (n int, err error) {
return w.write(len(s), nil, s)
}
// either dataB or dataS is non-zero.
func (w *responseWriter) write(lenData int, dataB []byte, dataS string) (n int, err error) {
rws := w.rws
if rws == nil {
panic("Write called after Handler finished")
}
if !rws.wroteHeader {
w.WriteHeader(200)
}
if dataB != nil {
return rws.bw.Write(dataB)
} else {
return rws.bw.WriteString(dataS)
}
}
func (w *responseWriter) handlerDone() {
rws := w.rws
if rws == nil {
panic("handlerDone called twice")
}
rws.handlerDone = true
w.Flush()
w.rws = nil
responseWriterStatePool.Put(rws)
}
|