src/shrpx_spdy_upstream.cc

   1 /*
   2  * nghttp2 - HTTP/2 C Library
   3  *
   4  * Copyright (c) 2012 Tatsuhiro Tsujikawa
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining
   7  * a copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sublicense, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be
  15  * included in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  20  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25 #include "shrpx_spdy_upstream.h"
  26
  27 #include <netinet/tcp.h>
  28 #include <assert.h>
  29 #include <cerrno>
  30 #include <sstream>
  31
  32 #include <nghttp2/nghttp2.h>
  33
  34 #include "shrpx_client_handler.h"
  35 #include "shrpx_downstream.h"
  36 #include "shrpx_downstream_connection.h"
  37 #include "shrpx_config.h"
  38 #include "shrpx_http.h"
  39 #include "shrpx_worker_config.h"
  40 #include "http2.h"
  41 #include "util.h"
  42 #include "template.h"
  43
  44 using namespace nghttp2;
  45
  46 namespace shrpx {
  47
  48 namespace {
  49 ssize_t send_callback(spdylay_session *session, const uint8_t *data, size_t len,
  50                       int flags, void *user_data) {
  51   auto upstream = static_cast<SpdyUpstream *>(user_data);
  52   auto handler = upstream->get_client_handler();
  53   auto wb = handler->get_wb();
  54
  55   if (wb->wleft() == 0) {
  56     return SPDYLAY_ERR_WOULDBLOCK;
  57   }
  58
  59   auto nread = wb->write(data, len);
  60
  61   return nread;
  62 }
  63 } // namespace
  64
  65 namespace {
  66 ssize_t recv_callback(spdylay_session *session, uint8_t *buf, size_t len,
  67                       int flags, void *user_data) {
  68   auto upstream = static_cast<SpdyUpstream *>(user_data);
  69   auto handler = upstream->get_client_handler();
  70   auto rb = handler->get_rb();
  71
  72   if (rb->rleft() == 0) {
  73     return SPDYLAY_ERR_WOULDBLOCK;
  74   }
  75
  76   auto nread = std::min(rb->rleft(), len);
  77
  78   memcpy(buf, rb->pos, nread);
  79   rb->drain(nread);
  80
  81   return nread;
  82 }
  83 } // namespace
  84
  85 namespace {
  86 void on_stream_close_callback(spdylay_session *session, int32_t stream_id,
  87                               spdylay_status_code status_code,
  88                               void *user_data) {
  89   auto upstream = static_cast<SpdyUpstream *>(user_data);
  90   if (LOG_ENABLED(INFO)) {
  91     ULOG(INFO, upstream) << "Stream stream_id=" << stream_id
  92                          << " is being closed";
  93   }
  94   auto downstream = upstream->find_downstream(stream_id);
  95   if (!downstream) {
  96     return;
  97   }
  98
  99   upstream->consume(stream_id, downstream->get_request_datalen());
 100
 101   downstream->reset_request_datalen();
 102
 103   if (downstream->get_request_state() == Downstream::CONNECT_FAIL) {
 104     upstream->remove_downstream(downstream);
 105     // downstrea was deleted
 106
 107     return;
 108   }
 109
 110   downstream->set_request_state(Downstream::STREAM_CLOSED);
 111   if (downstream->get_response_state() == Downstream::MSG_COMPLETE) {
 112     // At this point, downstream response was read
 113     if (!downstream->get_upgraded() &&
 114         !downstream->get_response_connection_close()) {
 115       // Keep-alive
 116       downstream->detach_downstream_connection();
 117     }
 118     upstream->remove_downstream(downstream);
 119     // downstrea was deleted
 120
 121     return;
 122   }
 123
 124   // At this point, downstream read may be paused.
 125
 126   // If shrpx_downstream::push_request_headers() failed, the
 127   // error is handled here.
 128   upstream->remove_downstream(downstream);
 129   // downstrea was deleted
 130
 131   // How to test this case? Request sufficient large download
 132   // and make client send RST_STREAM after it gets first DATA
 133   // frame chunk.
 134 }
 135 } // namespace
 136
 137 namespace {
 138 void on_ctrl_recv_callback(spdylay_session *session, spdylay_frame_type type,
 139                            spdylay_frame *frame, void *user_data) {
 140   auto upstream = static_cast<SpdyUpstream *>(user_data);
 141   switch (type) {
 142   case SPDYLAY_SYN_STREAM: {
 143     if (LOG_ENABLED(INFO)) {
 144       ULOG(INFO, upstream) << "Received upstream SYN_STREAM stream_id="
 145                            << frame->syn_stream.stream_id;
 146     }
 147
 148     auto downstream = upstream->add_pending_downstream(
 149         frame->syn_stream.stream_id, frame->syn_stream.pri);
 150
 151     downstream->reset_upstream_rtimer();
 152
 153     auto nv = frame->syn_stream.nv;
 154
 155     if (LOG_ENABLED(INFO)) {
 156       std::stringstream ss;
 157       for (size_t i = 0; nv[i]; i += 2) {
 158         ss << TTY_HTTP_HD << nv[i] << TTY_RST << ": " << nv[i + 1] << "\n";
 159       }
 160       ULOG(INFO, upstream) << "HTTP request headers. stream_id="
 161                            << downstream->get_stream_id() << "\n" << ss.str();
 162     }
 163
 164     for (size_t i = 0; nv[i]; i += 2) {
 165       downstream->add_request_header(nv[i], nv[i + 1]);
 166     }
 167
 168     if (downstream->index_request_headers() != 0) {
 169       if (upstream->error_reply(downstream, 400) != 0) {
 170         ULOG(FATAL, upstream) << "error_reply failed";
 171       }
 172       return;
 173     }
 174
 175     auto path = downstream->get_request_header(http2::HD__PATH);
 176     auto scheme = downstream->get_request_header(http2::HD__SCHEME);
 177     auto host = downstream->get_request_header(http2::HD__HOST);
 178     auto method = downstream->get_request_header(http2::HD__METHOD);
 179
 180     bool is_connect = method && "CONNECT" == method->value;
 181     if (!path || !host || !method || !http2::non_empty_value(host) ||
 182         !http2::non_empty_value(path) || !http2::non_empty_value(method) ||
 183         (!is_connect && (!scheme || !http2::non_empty_value(scheme)))) {
 184       upstream->rst_stream(downstream, SPDYLAY_INTERNAL_ERROR);
 185       return;
 186     }
 187
 188     downstream->set_request_method(method->value);
 189     if (is_connect) {
 190       downstream->set_request_http2_authority(path->value);
 191     } else {
 192       downstream->set_request_http2_scheme(scheme->value);
 193       downstream->set_request_http2_authority(host->value);
 194       downstream->set_request_path(path->value);
 195     }
 196
 197     if (!(frame->syn_stream.hd.flags & SPDYLAY_CTRL_FLAG_FIN)) {
 198       downstream->set_request_http2_expect_body(true);
 199     }
 200
 201     downstream->inspect_http2_request();
 202
 203     downstream->set_request_state(Downstream::HEADER_COMPLETE);
 204     if (frame->syn_stream.hd.flags & SPDYLAY_CTRL_FLAG_FIN) {
 205       if (!downstream->validate_request_bodylen()) {
 206         upstream->rst_stream(downstream, SPDYLAY_PROTOCOL_ERROR);
 207         return;
 208       }
 209
 210       downstream->disable_upstream_rtimer();
 211       downstream->set_request_state(Downstream::MSG_COMPLETE);
 212     }
 213
 214     upstream->start_downstream(downstream);
 215
 216     break;
 217   }
 218   default:
 219     break;
 220   }
 221 }
 222 } // namespace
 223
 224 void SpdyUpstream::start_downstream(Downstream *downstream) {
 225   auto next_downstream =
 226       downstream_queue_.pop_pending(downstream->get_stream_id());
 227   assert(next_downstream);
 228
 229   if (downstream_queue_.can_activate(
 230           downstream->get_request_http2_authority())) {
 231     initiate_downstream(std::move(next_downstream));
 232     return;
 233   }
 234
 235   downstream_queue_.add_blocked(std::move(next_downstream));
 236 }
 237
 238 void SpdyUpstream::initiate_downstream(std::unique_ptr<Downstream> downstream) {
 239   int rv = downstream->attach_downstream_connection(
 240       handler_->get_downstream_connection());
 241   if (rv != 0) {
 242     // If downstream connection fails, issue RST_STREAM.
 243     rst_stream(downstream.get(), SPDYLAY_INTERNAL_ERROR);
 244     downstream->set_request_state(Downstream::CONNECT_FAIL);
 245
 246     downstream_queue_.add_failure(std::move(downstream));
 247
 248     return;
 249   }
 250   rv = downstream->push_request_headers();
 251   if (rv != 0) {
 252     rst_stream(downstream.get(), SPDYLAY_INTERNAL_ERROR);
 253
 254     downstream_queue_.add_failure(std::move(downstream));
 255
 256     return;
 257   }
 258
 259   downstream_queue_.add_active(std::move(downstream));
 260 }
 261
 262 namespace {
 263 void on_data_chunk_recv_callback(spdylay_session *session, uint8_t flags,
 264                                  int32_t stream_id, const uint8_t *data,
 265                                  size_t len, void *user_data) {
 266   auto upstream = static_cast<SpdyUpstream *>(user_data);
 267   auto downstream = upstream->find_downstream(stream_id);
 268
 269   if (!downstream) {
 270     upstream->consume(stream_id, len);
 271
 272     return;
 273   }
 274
 275   downstream->reset_upstream_rtimer();
 276
 277   if (downstream->push_upload_data_chunk(data, len) != 0) {
 278     upstream->rst_stream(downstream, SPDYLAY_INTERNAL_ERROR);
 279
 280     upstream->consume(stream_id, len);
 281
 282     return;
 283   }
 284
 285   if (!upstream->get_flow_control()) {
 286     return;
 287   }
 288
 289   // If connection-level window control is not enabled (e.g,
 290   // spdy/3), spdylay_session_get_recv_data_length() is always
 291   // returns 0.
 292   if (spdylay_session_get_recv_data_length(session) >
 293       std::max(SPDYLAY_INITIAL_WINDOW_SIZE,
 294                1 << get_config()->http2_upstream_connection_window_bits)) {
 295     if (LOG_ENABLED(INFO)) {
 296       ULOG(INFO, upstream)
 297           << "Flow control error on connection: "
 298           << "recv_window_size="
 299           << spdylay_session_get_recv_data_length(session) << ", window_size="
 300           << (1 << get_config()->http2_upstream_connection_window_bits);
 301     }
 302     spdylay_session_fail_session(session, SPDYLAY_GOAWAY_PROTOCOL_ERROR);
 303     return;
 304   }
 305   if (spdylay_session_get_stream_recv_data_length(session, stream_id) >
 306       std::max(SPDYLAY_INITIAL_WINDOW_SIZE,
 307                1 << get_config()->http2_upstream_window_bits)) {
 308     if (LOG_ENABLED(INFO)) {
 309       ULOG(INFO, upstream) << "Flow control error: recv_window_size="
 310                            << spdylay_session_get_stream_recv_data_length(
 311                                   session, stream_id)
 312                            << ", initial_window_size="
 313                            << (1 << get_config()->http2_upstream_window_bits);
 314     }
 315     upstream->rst_stream(downstream, SPDYLAY_FLOW_CONTROL_ERROR);
 316     return;
 317   }
 318 }
 319 } // namespace
 320
 321 namespace {
 322 void on_data_recv_callback(spdylay_session *session, uint8_t flags,
 323                            int32_t stream_id, int32_t length, void *user_data) {
 324   auto upstream = static_cast<SpdyUpstream *>(user_data);
 325   auto downstream = upstream->find_downstream(stream_id);
 326   if (downstream && (flags & SPDYLAY_DATA_FLAG_FIN)) {
 327     if (!downstream->validate_request_bodylen()) {
 328       upstream->rst_stream(downstream, SPDYLAY_PROTOCOL_ERROR);
 329       return;
 330     }
 331
 332     downstream->disable_upstream_rtimer();
 333     downstream->end_upload_data();
 334     downstream->set_request_state(Downstream::MSG_COMPLETE);
 335   }
 336 }
 337 } // namespace
 338
 339 namespace {
 340 void on_ctrl_not_send_callback(spdylay_session *session,
 341                                spdylay_frame_type type, spdylay_frame *frame,
 342                                int error_code, void *user_data) {
 343   auto upstream = static_cast<SpdyUpstream *>(user_data);
 344   if (LOG_ENABLED(INFO)) {
 345     ULOG(INFO, upstream) << "Failed to send control frame type=" << type
 346                          << ", error_code=" << error_code << ":"
 347                          << spdylay_strerror(error_code);
 348   }
 349   if (type == SPDYLAY_SYN_REPLY && error_code != SPDYLAY_ERR_STREAM_CLOSED &&
 350       error_code != SPDYLAY_ERR_STREAM_CLOSING) {
 351     // To avoid stream hanging around, issue RST_STREAM.
 352     auto stream_id = frame->syn_reply.stream_id;
 353     auto downstream = upstream->find_downstream(stream_id);
 354     if (downstream) {
 355       upstream->rst_stream(downstream, SPDYLAY_INTERNAL_ERROR);
 356     }
 357   }
 358 }
 359 } // namespace
 360
 361 namespace {
 362 void on_ctrl_recv_parse_error_callback(spdylay_session *session,
 363                                        spdylay_frame_type type,
 364                                        const uint8_t *head, size_t headlen,
 365                                        const uint8_t *payload,
 366                                        size_t payloadlen, int error_code,
 367                                        void *user_data) {
 368   auto upstream = static_cast<SpdyUpstream *>(user_data);
 369   if (LOG_ENABLED(INFO)) {
 370     ULOG(INFO, upstream) << "Failed to parse received control frame. type="
 371                          << type << ", error_code=" << error_code << ":"
 372                          << spdylay_strerror(error_code);
 373   }
 374 }
 375 } // namespace
 376
 377 namespace {
 378 void on_unknown_ctrl_recv_callback(spdylay_session *session,
 379                                    const uint8_t *head, size_t headlen,
 380                                    const uint8_t *payload, size_t payloadlen,
 381                                    void *user_data) {
 382   auto upstream = static_cast<SpdyUpstream *>(user_data);
 383   if (LOG_ENABLED(INFO)) {
 384     ULOG(INFO, upstream) << "Received unknown control frame.";
 385   }
 386 }
 387 } // namespace
 388
 389 namespace {
 390 // Infer upstream RST_STREAM status code from downstream HTTP/2
 391 // error code.
 392 uint32_t infer_upstream_rst_stream_status_code(uint32_t downstream_error_code) {
 393   // Only propagate *_REFUSED_STREAM so that upstream client can
 394   // resend request.
 395   if (downstream_error_code == NGHTTP2_REFUSED_STREAM) {
 396     return SPDYLAY_REFUSED_STREAM;
 397   } else {
 398     return SPDYLAY_INTERNAL_ERROR;
 399   }
 400 }
 401 } // namespace
 402
 403 SpdyUpstream::SpdyUpstream(uint16_t version, ClientHandler *handler)
 404     : downstream_queue_(
 405           get_config()->http2_proxy
 406               ? get_config()->downstream_connections_per_host
 407               : get_config()->downstream_proto == PROTO_HTTP
 408                     ? get_config()->downstream_connections_per_frontend
 409                     : 0,
 410           !get_config()->http2_proxy),
 411       handler_(handler), session_(nullptr) {
 412   spdylay_session_callbacks callbacks;
 413   memset(&callbacks, 0, sizeof(callbacks));
 414   callbacks.send_callback = send_callback;
 415   callbacks.recv_callback = recv_callback;
 416   callbacks.on_stream_close_callback = on_stream_close_callback;
 417   callbacks.on_ctrl_recv_callback = on_ctrl_recv_callback;
 418   callbacks.on_data_chunk_recv_callback = on_data_chunk_recv_callback;
 419   callbacks.on_data_recv_callback = on_data_recv_callback;
 420   callbacks.on_ctrl_not_send_callback = on_ctrl_not_send_callback;
 421   callbacks.on_ctrl_recv_parse_error_callback =
 422       on_ctrl_recv_parse_error_callback;
 423   callbacks.on_unknown_ctrl_recv_callback = on_unknown_ctrl_recv_callback;
 424
 425   int rv;
 426   rv = spdylay_session_server_new(&session_, version, &callbacks, this);
 427   assert(rv == 0);
 428
 429   if (version >= SPDYLAY_PROTO_SPDY3) {
 430     int val = 1;
 431     flow_control_ = true;
 432     initial_window_size_ = 1 << get_config()->http2_upstream_window_bits;
 433     rv = spdylay_session_set_option(
 434         session_, SPDYLAY_OPT_NO_AUTO_WINDOW_UPDATE2, &val, sizeof(val));
 435     assert(rv == 0);
 436   } else {
 437     flow_control_ = false;
 438     initial_window_size_ = 0;
 439   }
 440   // TODO Maybe call from outside?
 441   std::array<spdylay_settings_entry, 2> entry;
 442   entry[0].settings_id = SPDYLAY_SETTINGS_MAX_CONCURRENT_STREAMS;
 443   entry[0].value = get_config()->http2_max_concurrent_streams;
 444   entry[0].flags = SPDYLAY_ID_FLAG_SETTINGS_NONE;
 445
 446   entry[1].settings_id = SPDYLAY_SETTINGS_INITIAL_WINDOW_SIZE;
 447   entry[1].value = initial_window_size_;
 448   entry[1].flags = SPDYLAY_ID_FLAG_SETTINGS_NONE;
 449
 450   rv = spdylay_submit_settings(session_, SPDYLAY_FLAG_SETTINGS_NONE,
 451                                entry.data(), entry.size());
 452   assert(rv == 0);
 453
 454   if (version >= SPDYLAY_PROTO_SPDY3_1 &&
 455       get_config()->http2_upstream_connection_window_bits > 16) {
 456     int32_t delta = (1 << get_config()->http2_upstream_connection_window_bits) -
 457                     SPDYLAY_INITIAL_WINDOW_SIZE;
 458     rv = spdylay_submit_window_update(session_, 0, delta);
 459     assert(rv == 0);
 460   }
 461
 462   handler_->reset_upstream_read_timeout(
 463       get_config()->http2_upstream_read_timeout);
 464
 465   handler_->signal_write();
 466 }
 467
 468 SpdyUpstream::~SpdyUpstream() { spdylay_session_del(session_); }
 469
 470 int SpdyUpstream::on_read() {
 471   int rv = 0;
 472
 473   rv = spdylay_session_recv(session_);
 474   if (rv < 0) {
 475     if (rv != SPDYLAY_ERR_EOF) {
 476       ULOG(ERROR, this) << "spdylay_session_recv() returned error: "
 477                         << spdylay_strerror(rv);
 478     }
 479     return rv;
 480   }
 481
 482   handler_->signal_write();
 483
 484   return 0;
 485 }
 486
 487 // After this function call, downstream may be deleted.
 488 int SpdyUpstream::on_write() {
 489   int rv = 0;
 490
 491   rv = spdylay_session_send(session_);
 492   if (rv != 0) {
 493     ULOG(ERROR, this) << "spdylay_session_send() returned error: "
 494                       << spdylay_strerror(rv);
 495     return rv;
 496   }
 497
 498   if (spdylay_session_want_read(session_) == 0 &&
 499       spdylay_session_want_write(session_) == 0 &&
 500       handler_->get_wb()->rleft() == 0) {
 501     if (LOG_ENABLED(INFO)) {
 502       ULOG(INFO, this) << "No more read/write for this SPDY session";
 503     }
 504     return -1;
 505   }
 506   return 0;
 507 }
 508
 509 ClientHandler *SpdyUpstream::get_client_handler() const { return handler_; }
 510
 511 int SpdyUpstream::downstream_read(DownstreamConnection *dconn) {
 512   auto downstream = dconn->get_downstream();
 513
 514   if (downstream->get_request_state() == Downstream::STREAM_CLOSED) {
 515     // If upstream SPDY stream was closed, we just close downstream,
 516     // because there is no consumer now. Downstream connection is also
 517     // closed in this case.
 518     remove_downstream(downstream);
 519     // downstrea was deleted
 520
 521     return 0;
 522   }
 523
 524   if (downstream->get_response_state() == Downstream::MSG_RESET) {
 525     // The downstream stream was reset (canceled). In this case,
 526     // RST_STREAM to the upstream and delete downstream connection
 527     // here. Deleting downstream will be taken place at
 528     // on_stream_close_callback.
 529     rst_stream(downstream,
 530                infer_upstream_rst_stream_status_code(
 531                    downstream->get_response_rst_stream_error_code()));
 532     downstream->pop_downstream_connection();
 533     dconn = nullptr;
 534   } else if (downstream->get_response_state() == Downstream::MSG_BAD_HEADER) {
 535     if (error_reply(downstream, 502) != 0) {
 536       return -1;
 537     }
 538     downstream->pop_downstream_connection();
 539     // dconn was deleted
 540     dconn = nullptr;
 541   } else {
 542     auto rv = downstream->on_read();
 543     if (rv == SHRPX_ERR_EOF) {
 544       return downstream_eof(dconn);
 545     }
 546     if (rv != 0) {
 547       if (rv != SHRPX_ERR_NETWORK) {
 548         if (LOG_ENABLED(INFO)) {
 549           DCLOG(INFO, dconn) << "HTTP parser failure";
 550         }
 551       }
 552       return downstream_error(dconn, Downstream::EVENT_ERROR);
 553     }
 554     // Detach downstream connection early so that it could be reused
 555     // without hitting server's request timeout.
 556     if (downstream->get_response_state() == Downstream::MSG_COMPLETE &&
 557         !downstream->get_response_connection_close()) {
 558       // Keep-alive
 559       downstream->detach_downstream_connection();
 560     }
 561   }
 562
 563   handler_->signal_write();
 564   // At this point, downstream may be deleted.
 565
 566   return 0;
 567 }
 568
 569 int SpdyUpstream::downstream_write(DownstreamConnection *dconn) {
 570   int rv;
 571   rv = dconn->on_write();
 572   if (rv == SHRPX_ERR_NETWORK) {
 573     return downstream_error(dconn, Downstream::EVENT_ERROR);
 574   }
 575   if (rv != 0) {
 576     return -1;
 577   }
 578   return 0;
 579 }
 580
 581 int SpdyUpstream::downstream_eof(DownstreamConnection *dconn) {
 582   auto downstream = dconn->get_downstream();
 583
 584   if (LOG_ENABLED(INFO)) {
 585     DCLOG(INFO, dconn) << "EOF. stream_id=" << downstream->get_stream_id();
 586   }
 587   if (downstream->get_request_state() == Downstream::STREAM_CLOSED) {
 588     // If stream was closed already, we don't need to send reply at
 589     // the first place. We can delete downstream.
 590     remove_downstream(downstream);
 591     // downstream was deleted
 592
 593     return 0;
 594   }
 595
 596   // Delete downstream connection. If we don't delete it here, it will
 597   // be pooled in on_stream_close_callback.
 598   downstream->pop_downstream_connection();
 599   // dconn was deleted
 600   dconn = nullptr;
 601   // downstream wil be deleted in on_stream_close_callback.
 602   if (downstream->get_response_state() == Downstream::HEADER_COMPLETE) {
 603     // Server may indicate the end of the request by EOF
 604     if (LOG_ENABLED(INFO)) {
 605       ULOG(INFO, this) << "Downstream body was ended by EOF";
 606     }
 607     downstream->set_response_state(Downstream::MSG_COMPLETE);
 608
 609     // For tunneled connection, MSG_COMPLETE signals
 610     // downstream_data_read_callback to send RST_STREAM after pending
 611     // response body is sent. This is needed to ensure that RST_STREAM
 612     // is sent after all pending data are sent.
 613     on_downstream_body_complete(downstream);
 614   } else if (downstream->get_response_state() != Downstream::MSG_COMPLETE) {
 615     // If stream was not closed, then we set MSG_COMPLETE and let
 616     // on_stream_close_callback delete downstream.
 617     if (error_reply(downstream, 502) != 0) {
 618       return -1;
 619     }
 620   }
 621   handler_->signal_write();
 622   // At this point, downstream may be deleted.
 623   return 0;
 624 }
 625
 626 int SpdyUpstream::downstream_error(DownstreamConnection *dconn, int events) {
 627   auto downstream = dconn->get_downstream();
 628
 629   if (LOG_ENABLED(INFO)) {
 630     if (events & Downstream::EVENT_ERROR) {
 631       DCLOG(INFO, dconn) << "Downstream network/general error";
 632     } else {
 633       DCLOG(INFO, dconn) << "Timeout";
 634     }
 635     if (downstream->get_upgraded()) {
 636       DCLOG(INFO, dconn) << "Note: this is tunnel connection";
 637     }
 638   }
 639
 640   if (downstream->get_request_state() == Downstream::STREAM_CLOSED) {
 641     remove_downstream(downstream);
 642     // downstream was deleted
 643
 644     return 0;
 645   }
 646
 647   // Delete downstream connection. If we don't delete it here, it will
 648   // be pooled in on_stream_close_callback.
 649   downstream->pop_downstream_connection();
 650   // dconn was deleted
 651   dconn = nullptr;
 652
 653   if (downstream->get_response_state() == Downstream::MSG_COMPLETE) {
 654     // For SSL tunneling, we issue RST_STREAM. For other types of
 655     // stream, we don't have to do anything since response was
 656     // complete.
 657     if (downstream->get_upgraded()) {
 658       // We want "NO_ERROR" error code but SPDY does not have such
 659       // code for RST_STREAM.
 660       rst_stream(downstream, SPDYLAY_INTERNAL_ERROR);
 661     }
 662   } else {
 663     if (downstream->get_response_state() == Downstream::HEADER_COMPLETE) {
 664       if (downstream->get_upgraded()) {
 665         on_downstream_body_complete(downstream);
 666       } else {
 667         rst_stream(downstream, SPDYLAY_INTERNAL_ERROR);
 668       }
 669     } else {
 670       unsigned int status;
 671       if (events & Downstream::EVENT_TIMEOUT) {
 672         status = 504;
 673       } else {
 674         status = 502;
 675       }
 676       if (error_reply(downstream, status) != 0) {
 677         return -1;
 678       }
 679     }
 680     downstream->set_response_state(Downstream::MSG_COMPLETE);
 681   }
 682   handler_->signal_write();
 683   // At this point, downstream may be deleted.
 684   return 0;
 685 }
 686
 687 int SpdyUpstream::rst_stream(Downstream *downstream, int status_code) {
 688   if (LOG_ENABLED(INFO)) {
 689     ULOG(INFO, this) << "RST_STREAM stream_id=" << downstream->get_stream_id();
 690   }
 691   int rv;
 692   rv = spdylay_submit_rst_stream(session_, downstream->get_stream_id(),
 693                                  status_code);
 694   if (rv < SPDYLAY_ERR_FATAL) {
 695     ULOG(FATAL, this) << "spdylay_submit_rst_stream() failed: "
 696                       << spdylay_strerror(rv);
 697     DIE();
 698   }
 699   return 0;
 700 }
 701
 702 namespace {
 703 ssize_t spdy_data_read_callback(spdylay_session *session, int32_t stream_id,
 704                                 uint8_t *buf, size_t length, int *eof,
 705                                 spdylay_data_source *source, void *user_data) {
 706   auto downstream = static_cast<Downstream *>(source->ptr);
 707   auto upstream = static_cast<SpdyUpstream *>(downstream->get_upstream());
 708   auto body = downstream->get_response_buf();
 709   assert(body);
 710
 711   auto dconn = downstream->get_downstream_connection();
 712
 713   if (body->rleft() == 0 && dconn &&
 714       downstream->get_response_state() != Downstream::MSG_COMPLETE) {
 715     // Try to read more if buffer is empty.  This will help small
 716     // buffer and make priority handling a bit better.
 717     if (upstream->downstream_read(dconn) != 0) {
 718       return SPDYLAY_ERR_CALLBACK_FAILURE;
 719     }
 720   }
 721
 722   auto nread = body->remove(buf, length);
 723   auto body_empty = body->rleft() == 0;
 724
 725   if (nread == 0 &&
 726       downstream->get_response_state() == Downstream::MSG_COMPLETE) {
 727     if (!downstream->get_upgraded()) {
 728       *eof = 1;
 729     } else {
 730       // For tunneling, issue RST_STREAM to finish the stream.
 731       if (LOG_ENABLED(INFO)) {
 732         ULOG(INFO, upstream)
 733             << "RST_STREAM to tunneled stream stream_id=" << stream_id;
 734       }
 735       upstream->rst_stream(
 736           downstream, infer_upstream_rst_stream_status_code(
 737                           downstream->get_response_rst_stream_error_code()));
 738     }
 739   }
 740
 741   if (body_empty) {
 742     downstream->disable_upstream_wtimer();
 743   } else {
 744     downstream->reset_upstream_wtimer();
 745   }
 746
 747   if (nread > 0 && downstream->resume_read(SHRPX_NO_BUFFER, nread) != 0) {
 748     return SPDYLAY_ERR_CALLBACK_FAILURE;
 749   }
 750
 751   if (nread == 0 && *eof != 1) {
 752     return SPDYLAY_ERR_DEFERRED;
 753   }
 754
 755   if (nread > 0) {
 756     downstream->add_response_sent_bodylen(nread);
 757   }
 758
 759   return nread;
 760 }
 761 } // namespace
 762
 763 int SpdyUpstream::error_reply(Downstream *downstream,
 764                               unsigned int status_code) {
 765   int rv;
 766   auto html = http::create_error_html(status_code);
 767   downstream->set_response_http_status(status_code);
 768   auto body = downstream->get_response_buf();
 769   body->append(html.c_str(), html.size());
 770   downstream->set_response_state(Downstream::MSG_COMPLETE);
 771
 772   spdylay_data_provider data_prd;
 773   data_prd.source.ptr = downstream;
 774   data_prd.read_callback = spdy_data_read_callback;
 775
 776   std::string content_length = util::utos(html.size());
 777   std::string status_string = http2::get_status_string(status_code);
 778   const char *nv[] = {":status",        status_string.c_str(),
 779                       ":version",       "http/1.1",
 780                       "content-type",   "text/html; charset=UTF-8",
 781                       "server",         get_config()->server_name,
 782                       "content-length", content_length.c_str(),
 783                       nullptr};
 784
 785   rv = spdylay_submit_response(session_, downstream->get_stream_id(), nv,
 786                                &data_prd);
 787   if (rv < SPDYLAY_ERR_FATAL) {
 788     ULOG(FATAL, this) << "spdylay_submit_response() failed: "
 789                       << spdylay_strerror(rv);
 790     return -1;
 791   }
 792
 793   return 0;
 794 }
 795
 796 Downstream *SpdyUpstream::add_pending_downstream(int32_t stream_id,
 797                                                  int32_t priority) {
 798   auto downstream = make_unique<Downstream>(this, stream_id, priority);
 799   auto res = downstream.get();
 800
 801   downstream_queue_.add_pending(std::move(downstream));
 802
 803   return res;
 804 }
 805
 806 void SpdyUpstream::remove_downstream(Downstream *downstream) {
 807   if (downstream->accesslog_ready()) {
 808     handler_->write_accesslog(downstream);
 809   }
 810
 811   auto next_downstream =
 812       downstream_queue_.remove_and_pop_blocked(downstream->get_stream_id());
 813
 814   if (next_downstream) {
 815     initiate_downstream(std::move(next_downstream));
 816   }
 817 }
 818
 819 Downstream *SpdyUpstream::find_downstream(int32_t stream_id) {
 820   return downstream_queue_.find(stream_id);
 821 }
 822
 823 spdylay_session *SpdyUpstream::get_http2_session() { return session_; }
 824
 825 // WARNING: Never call directly or indirectly spdylay_session_send or
 826 // spdylay_session_recv. These calls may delete downstream.
 827 int SpdyUpstream::on_downstream_header_complete(Downstream *downstream) {
 828   if (downstream->get_non_final_response()) {
 829     // SPDY does not support non-final response.  We could send it
 830     // with HEADERS and final response in SYN_REPLY, but it is not
 831     // official way.
 832     downstream->clear_response_headers();
 833
 834     return 0;
 835   }
 836
 837   if (LOG_ENABLED(INFO)) {
 838     DLOG(INFO, downstream) << "HTTP response header completed";
 839   }
 840
 841   if (!get_config()->http2_proxy && !get_config()->client_proxy &&
 842       !get_config()->no_location_rewrite) {
 843     downstream->rewrite_location_response_header(
 844         downstream->get_request_http2_scheme());
 845   }
 846   size_t nheader = downstream->get_response_headers().size();
 847   // 8 means server, :status, :version and possible via header field.
 848   auto nv = make_unique<const char *[]>(
 849       nheader * 2 + 8 + get_config()->add_response_headers.size() * 2 + 1);
 850
 851   size_t hdidx = 0;
 852   std::string via_value;
 853   std::string status_string =
 854       http2::get_status_string(downstream->get_response_http_status());
 855   nv[hdidx++] = ":status";
 856   nv[hdidx++] = status_string.c_str();
 857   nv[hdidx++] = ":version";
 858   nv[hdidx++] = "HTTP/1.1";
 859   for (auto &hd : downstream->get_response_headers()) {
 860     if (hd.name.empty() || hd.name.c_str()[0] == ':') {
 861       continue;
 862     }
 863     switch (hd.token) {
 864     case http2::HD_CONNECTION:
 865     case http2::HD_KEEP_ALIVE:
 866     case http2::HD_PROXY_CONNECTION:
 867     case http2::HD_TRANSFER_ENCODING:
 868     case http2::HD_VIA:
 869     case http2::HD_SERVER:
 870       continue;
 871     }
 872
 873     nv[hdidx++] = hd.name.c_str();
 874     nv[hdidx++] = hd.value.c_str();
 875   }
 876
 877   if (!get_config()->http2_proxy && !get_config()->client_proxy) {
 878     nv[hdidx++] = "server";
 879     nv[hdidx++] = get_config()->server_name;
 880   } else {
 881     auto server = downstream->get_response_header(http2::HD_SERVER);
 882     if (server) {
 883       nv[hdidx++] = "server";
 884       nv[hdidx++] = server->value.c_str();
 885     }
 886   }
 887
 888   auto via = downstream->get_response_header(http2::HD_VIA);
 889   if (get_config()->no_via) {
 890     if (via) {
 891       nv[hdidx++] = "via";
 892       nv[hdidx++] = via->value.c_str();
 893     }
 894   } else {
 895     if (via) {
 896       via_value = via->value;
 897       via_value += ", ";
 898     }
 899     via_value += http::create_via_header_value(
 900         downstream->get_response_major(), downstream->get_response_minor());
 901     nv[hdidx++] = "via";
 902     nv[hdidx++] = via_value.c_str();
 903   }
 904
 905   for (auto &p : get_config()->add_response_headers) {
 906     nv[hdidx++] = p.first.c_str();
 907     nv[hdidx++] = p.second.c_str();
 908   }
 909
 910   nv[hdidx++] = 0;
 911   if (LOG_ENABLED(INFO)) {
 912     std::stringstream ss;
 913     for (size_t i = 0; nv[i]; i += 2) {
 914       ss << TTY_HTTP_HD << nv[i] << TTY_RST << ": " << nv[i + 1] << "\n";
 915     }
 916     ULOG(INFO, this) << "HTTP response headers. stream_id="
 917                      << downstream->get_stream_id() << "\n" << ss.str();
 918   }
 919   spdylay_data_provider data_prd;
 920   data_prd.source.ptr = downstream;
 921   data_prd.read_callback = spdy_data_read_callback;
 922
 923   int rv;
 924   rv = spdylay_submit_response(session_, downstream->get_stream_id(), nv.get(),
 925                                &data_prd);
 926   if (rv != 0) {
 927     ULOG(FATAL, this) << "spdylay_submit_response() failed";
 928     return -1;
 929   }
 930
 931   return 0;
 932 }
 933
 934 // WARNING: Never call directly or indirectly spdylay_session_send or
 935 // spdylay_session_recv. These calls may delete downstream.
 936 int SpdyUpstream::on_downstream_body(Downstream *downstream,
 937                                      const uint8_t *data, size_t len,
 938                                      bool flush) {
 939   auto body = downstream->get_response_buf();
 940   body->append(data, len);
 941
 942   if (flush) {
 943     spdylay_session_resume_data(session_, downstream->get_stream_id());
 944
 945     downstream->ensure_upstream_wtimer();
 946   }
 947
 948   return 0;
 949 }
 950
 951 // WARNING: Never call directly or indirectly spdylay_session_send or
 952 // spdylay_session_recv. These calls may delete downstream.
 953 int SpdyUpstream::on_downstream_body_complete(Downstream *downstream) {
 954   if (LOG_ENABLED(INFO)) {
 955     DLOG(INFO, downstream) << "HTTP response completed";
 956   }
 957
 958   if (!downstream->validate_response_bodylen()) {
 959     rst_stream(downstream, SPDYLAY_PROTOCOL_ERROR);
 960     downstream->set_response_connection_close(true);
 961     return 0;
 962   }
 963
 964   spdylay_session_resume_data(session_, downstream->get_stream_id());
 965   downstream->ensure_upstream_wtimer();
 966
 967   return 0;
 968 }
 969
 970 bool SpdyUpstream::get_flow_control() const { return flow_control_; }
 971
 972 void SpdyUpstream::pause_read(IOCtrlReason reason) {}
 973
 974 int SpdyUpstream::resume_read(IOCtrlReason reason, Downstream *downstream,
 975                               size_t consumed) {
 976   if (get_flow_control()) {
 977     assert(downstream->get_request_datalen() >= consumed);
 978
 979     if (consume(downstream->get_stream_id(), consumed) != 0) {
 980       return -1;
 981     }
 982
 983     downstream->dec_request_datalen(consumed);
 984   }
 985
 986   handler_->signal_write();
 987   return 0;
 988 }
 989
 990 int SpdyUpstream::on_downstream_abort_request(Downstream *downstream,
 991                                               unsigned int status_code) {
 992   int rv;
 993
 994   rv = error_reply(downstream, status_code);
 995
 996   if (rv != 0) {
 997     return -1;
 998   }
 999
1000   handler_->signal_write();
1001   return 0;
1002 }
1003
1004 int SpdyUpstream::consume(int32_t stream_id, size_t len) {
1005   int rv;
1006
1007   rv = spdylay_session_consume(session_, stream_id, len);
1008
1009   if (rv != 0) {
1010     ULOG(WARN, this) << "spdylay_session_consume() returned error: "
1011                      << spdylay_strerror(rv);
1012     return -1;
1013   }
1014
1015   return 0;
1016 }
1017
1018 int SpdyUpstream::on_timeout(Downstream *downstream) {
1019   if (LOG_ENABLED(INFO)) {
1020     ULOG(INFO, this) << "Stream timeout stream_id="
1021                      << downstream->get_stream_id();
1022   }
1023
1024   rst_stream(downstream, SPDYLAY_INTERNAL_ERROR);
1025
1026   return 0;
1027 }
1028
1029 void SpdyUpstream::on_handler_delete() {
1030   for (auto &ent : downstream_queue_.get_active_downstreams()) {
1031     if (ent.second->accesslog_ready()) {
1032       handler_->write_accesslog(ent.second.get());
1033     }
1034   }
1035 }
1036
1037 int SpdyUpstream::on_downstream_reset(bool no_retry) {
1038   int rv;
1039
1040   for (auto &ent : downstream_queue_.get_active_downstreams()) {
1041     auto downstream = ent.second.get();
1042     if ((downstream->get_request_state() != Downstream::HEADER_COMPLETE &&
1043          downstream->get_request_state() != Downstream::MSG_COMPLETE) ||
1044         downstream->get_response_state() != Downstream::INITIAL) {
1045       rst_stream(downstream, SPDYLAY_INTERNAL_ERROR);
1046       downstream->pop_downstream_connection();
1047       continue;
1048     }
1049
1050     downstream->pop_downstream_connection();
1051
1052     downstream->add_retry();
1053
1054     if (no_retry || downstream->no_more_retry()) {
1055       if (on_downstream_abort_request(downstream, 503) != 0) {
1056         return -1;
1057       }
1058       return 0;
1059     }
1060
1061     // downstream connection is clean; we can retry with new
1062     // downstream connection.
1063
1064     rv = downstream->attach_downstream_connection(
1065         handler_->get_downstream_connection());
1066     if (rv != 0) {
1067       rst_stream(downstream, SPDYLAY_INTERNAL_ERROR);
1068       downstream->pop_downstream_connection();
1069       continue;
1070     }
1071   }
1072
1073   handler_->signal_write();
1074
1075   return 0;
1076 }
1077
1078 MemchunkPool *SpdyUpstream::get_mcpool() { return &mcpool_; }
1079
1080 } // namespace shrpx