git.sesse.net Git - cubemap/blob - server.cpp

   1 #include <assert.h>
   2 #include <errno.h>
   3 #include <netinet/in.h>
   4 #include <pthread.h>
   5 #include <stdint.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <sys/epoll.h>
  10 #include <sys/sendfile.h>
  11 #include <sys/socket.h>
  12 #include <sys/types.h>
  13 #include <unistd.h>
  14 #include <algorithm>
  15 #include <map>
  16 #include <string>
  17 #include <utility>
  18 #include <vector>
  19
  20 #include "tlse.h"
  21
  22 #include "acceptor.h"
  23 #include "accesslog.h"
  24 #include "log.h"
  25 #include "metacube2.h"
  26 #include "parse.h"
  27 #include "server.h"
  28 #include "state.pb.h"
  29 #include "stream.h"
  30 #include "util.h"
  31
  32 #ifndef SO_MAX_PACING_RATE
  33 #define SO_MAX_PACING_RATE 47
  34 #endif
  35
  36 using namespace std;
  37
  38 extern AccessLogThread *access_log;
  39
  40 namespace {
  41
  42 inline bool is_equal(timespec a, timespec b)
  43 {
  44         return a.tv_sec == b.tv_sec &&
  45                a.tv_nsec == b.tv_nsec;
  46 }
  47
  48 inline bool is_earlier(timespec a, timespec b)
  49 {
  50         if (a.tv_sec != b.tv_sec)
  51                 return a.tv_sec < b.tv_sec;
  52         return a.tv_nsec < b.tv_nsec;
  53 }
  54
  55 }  // namespace
  56
  57 Server::Server()
  58 {
  59         epoll_fd = epoll_create(1024);  // Size argument is ignored.
  60         if (epoll_fd == -1) {
  61                 log_perror("epoll_fd");
  62                 exit(1);
  63         }
  64 }
  65
  66 Server::~Server()
  67 {
  68         safe_close(epoll_fd);
  69 }
  70
  71 vector<ClientStats> Server::get_client_stats() const
  72 {
  73         vector<ClientStats> ret;
  74
  75         lock_guard<mutex> lock(mu);
  76         for (const auto &fd_and_client : clients) {
  77                 ret.push_back(fd_and_client.second.get_stats());
  78         }
  79         return ret;
  80 }
  81
  82 void Server::do_work()
  83 {
  84         while (!should_stop()) {
  85                 // Wait until there's activity on at least one of the fds,
  86                 // or 20 ms (about one frame at 50 fps) has elapsed.
  87                 //
  88                 // We could in theory wait forever and rely on wakeup()
  89                 // from add_client_deferred() and add_data_deferred(),
  90                 // but wakeup is a pretty expensive operation, and the
  91                 // two threads might end up fighting over a lock, so it's
  92                 // seemingly (much) more efficient to just have a timeout here.
  93                 int nfds = epoll_pwait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS, &sigset_without_usr1_block);
  94                 if (nfds == -1 && errno != EINTR) {
  95                         log_perror("epoll_wait");
  96                         exit(1);
  97                 }
  98
  99                 lock_guard<mutex> lock(mu);  // We release the mutex between iterations.
 100
 101                 process_queued_data();
 102
 103                 // Process each client where we have socket activity.
 104                 for (int i = 0; i < nfds; ++i) {
 105                         Client *client = reinterpret_cast<Client *>(events[i].data.ptr);
 106
 107                         if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
 108                                 close_client(client);
 109                                 continue;
 110                         }
 111
 112                         process_client(client);
 113                 }
 114
 115                 // Process each client where its stream has new data,
 116                 // even if there was no socket activity.
 117                 for (unique_ptr<Stream> &stream : streams) {
 118                         vector<Client *> to_process;
 119                         swap(stream->to_process, to_process);
 120                         for (Client *client : to_process) {
 121                                 process_client(client);
 122                         }
 123                 }
 124
 125                 // Finally, go through each client to see if it's timed out
 126                 // in the READING_REQUEST state. (Seemingly there are clients
 127                 // that can hold sockets up for days at a time without sending
 128                 // anything at all.)
 129                 timespec timeout_time;
 130                 if (clock_gettime(CLOCK_MONOTONIC_COARSE, &timeout_time) == -1) {
 131                         log_perror("clock_gettime(CLOCK_MONOTONIC_COARSE)");
 132                         continue;
 133                 }
 134                 timeout_time.tv_sec -= REQUEST_READ_TIMEOUT_SEC;
 135                 while (!clients_ordered_by_connect_time.empty()) {
 136                         const pair<timespec, int> &connect_time_and_fd = clients_ordered_by_connect_time.front();
 137
 138                         // See if we have reached the end of clients to process.
 139                         if (is_earlier(timeout_time, connect_time_and_fd.first)) {
 140                                 break;
 141                         }
 142
 143                         // If this client doesn't exist anymore, just ignore it
 144                         // (it was deleted earlier).
 145                         auto client_it = clients.find(connect_time_and_fd.second);
 146                         if (client_it == clients.end()) {
 147                                 clients_ordered_by_connect_time.pop();
 148                                 continue;
 149                         }
 150                         Client *client = &client_it->second;
 151                         if (!is_equal(client->connect_time, connect_time_and_fd.first)) {
 152                                 // Another client has taken this fd in the meantime.
 153                                 clients_ordered_by_connect_time.pop();
 154                                 continue;
 155                         }
 156
 157                         if (client->state != Client::READING_REQUEST) {
 158                                 // Only READING_REQUEST can time out.
 159                                 clients_ordered_by_connect_time.pop();
 160                                 continue;
 161                         }
 162
 163                         // OK, it timed out.
 164                         close_client(client);
 165                         clients_ordered_by_connect_time.pop();
 166                 }
 167         }
 168 }
 169
 170 CubemapStateProto Server::serialize(unordered_map<const string *, size_t> *short_response_pool)
 171 {
 172         // We don't serialize anything queued, so empty the queues.
 173         process_queued_data();
 174
 175         // Set all clients in a consistent state before serializing
 176         // (ie., they have no remaining lost data). Otherwise, increasing
 177         // the backlog could take clients into a newly valid area of the backlog,
 178         // sending a stream of zeros instead of skipping the data as it should.
 179         //
 180         // TODO: Do this when clients are added back from serialized state instead;
 181         // it would probably be less wasteful.
 182         for (auto &fd_and_client : clients) {
 183                 skip_lost_data(&fd_and_client.second);
 184         }
 185
 186         CubemapStateProto serialized;
 187         for (const auto &fd_and_client : clients) {
 188                 serialized.add_clients()->MergeFrom(fd_and_client.second.serialize(short_response_pool));
 189         }
 190         for (unique_ptr<Stream> &stream : streams) {
 191                 serialized.add_streams()->MergeFrom(stream->serialize());
 192         }
 193         return serialized;
 194 }
 195
 196 void Server::add_client_deferred(int sock, Acceptor *acceptor)
 197 {
 198         lock_guard<mutex> lock(queued_clients_mutex);
 199         queued_add_clients.push_back(std::make_pair(sock, acceptor));
 200 }
 201
 202 void Server::add_client(int sock, Acceptor *acceptor)
 203 {
 204         const bool is_tls = acceptor->is_tls();
 205         auto inserted = clients.insert(make_pair(sock, Client(sock)));
 206         assert(inserted.second == true);  // Should not already exist.
 207         Client *client_ptr = &inserted.first->second;
 208
 209         // Connection timestamps must be nondecreasing. I can't find any guarantee
 210         // that even the monotonic clock can't go backwards by a small amount
 211         // (think switching between CPUs with non-synchronized TSCs), so if
 212         // this actually should happen, we hack around it by fudging
 213         // connect_time.
 214         if (!clients_ordered_by_connect_time.empty() &&
 215             is_earlier(client_ptr->connect_time, clients_ordered_by_connect_time.back().first)) {
 216                 client_ptr->connect_time = clients_ordered_by_connect_time.back().first;
 217         }
 218         clients_ordered_by_connect_time.push(make_pair(client_ptr->connect_time, sock));
 219
 220         // Start listening on data from this socket.
 221         epoll_event ev;
 222         if (is_tls) {
 223                 // Even in the initial state (READING_REQUEST), TLS needs to
 224                 // send data for the handshake, and thus might end up needing
 225                 // to know about EPOLLOUT.
 226                 ev.events = EPOLLIN | EPOLLOUT | EPOLLET | EPOLLRDHUP;
 227         } else {
 228                 // EPOLLOUT will be added once we go out of READING_REQUEST.
 229                 ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
 230         }
 231         ev.data.ptr = client_ptr;
 232         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
 233                 log_perror("epoll_ctl(EPOLL_CTL_ADD)");
 234                 exit(1);
 235         }
 236
 237         if (is_tls) {
 238                 assert(tls_server_contexts.count(acceptor));
 239                 client_ptr->tls_context = tls_accept(tls_server_contexts[acceptor]);
 240                 if (client_ptr->tls_context == nullptr) {
 241                         log(ERROR, "tls_accept() failed");
 242                         close_client(client_ptr);
 243                         return;
 244                 }
 245                 tls_make_exportable(client_ptr->tls_context, 1);
 246         }
 247
 248         process_client(client_ptr);
 249 }
 250
 251 void Server::add_client_from_serialized(const ClientProto &client, const vector<shared_ptr<const string>> &short_responses)
 252 {
 253         lock_guard<mutex> lock(mu);
 254         Stream *stream;
 255         int stream_index = lookup_stream_by_url(client.url());
 256         if (stream_index == -1) {
 257                 assert(client.state() != Client::SENDING_DATA);
 258                 stream = nullptr;
 259         } else {
 260                 stream = streams[stream_index].get();
 261         }
 262         auto inserted = clients.insert(make_pair(client.sock(), Client(client, short_responses, stream)));
 263         assert(inserted.second == true);  // Should not already exist.
 264         Client *client_ptr = &inserted.first->second;
 265
 266         // Connection timestamps must be nondecreasing.
 267         assert(clients_ordered_by_connect_time.empty() ||
 268                !is_earlier(client_ptr->connect_time, clients_ordered_by_connect_time.back().first));
 269         clients_ordered_by_connect_time.push(make_pair(client_ptr->connect_time, client.sock()));
 270
 271         // Start listening on data from this socket.
 272         epoll_event ev;
 273         if (client.state() == Client::READING_REQUEST) {
 274                 // See the corresponding comment in Server::add_client().
 275                 if (client.has_tls_context()) {
 276                         ev.events = EPOLLIN | EPOLLOUT | EPOLLET | EPOLLRDHUP;
 277                 } else {
 278                         ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
 279                 }
 280         } else {
 281                 // If we don't have more data for this client, we'll be putting it into
 282                 // the sleeping array again soon.
 283                 ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
 284         }
 285         ev.data.ptr = client_ptr;
 286         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, client.sock(), &ev) == -1) {
 287                 log_perror("epoll_ctl(EPOLL_CTL_ADD)");
 288                 exit(1);
 289         }
 290
 291         if (client_ptr->state == Client::WAITING_FOR_KEYFRAME ||
 292             client_ptr->state == Client::PREBUFFERING ||
 293             (client_ptr->state == Client::SENDING_DATA &&
 294              client_ptr->stream_pos == client_ptr->stream->bytes_received)) {
 295                 client_ptr->stream->put_client_to_sleep(client_ptr);
 296         } else {
 297                 process_client(client_ptr);
 298         }
 299 }
 300
 301 int Server::lookup_stream_by_url(const string &url) const
 302 {
 303         map<string, int>::const_iterator stream_url_it = stream_url_map.find(url);
 304         if (stream_url_it == stream_url_map.end()) {
 305                 return -1;
 306         }
 307         return stream_url_it->second;
 308 }
 309
 310 int Server::add_stream(const string &url,
 311                        const string &hls_url,
 312                        size_t backlog_size,
 313                        size_t prebuffering_bytes,
 314                        Stream::Encoding encoding,
 315                        Stream::Encoding src_encoding,
 316                        unsigned hls_frag_duration,
 317                        size_t hls_backlog_margin,
 318                        const string &allow_origin)
 319 {
 320         lock_guard<mutex> lock(mu);
 321         stream_url_map.insert(make_pair(url, streams.size()));
 322         if (!hls_url.empty()) {
 323                 stream_hls_url_map.insert(make_pair(hls_url, streams.size()));
 324         }
 325         streams.emplace_back(new Stream(url, backlog_size, prebuffering_bytes, encoding, src_encoding, hls_frag_duration, hls_backlog_margin, allow_origin));
 326         return streams.size() - 1;
 327 }
 328
 329 int Server::add_stream_from_serialized(const StreamProto &stream, int data_fd)
 330 {
 331         lock_guard<mutex> lock(mu);
 332         stream_url_map.insert(make_pair(stream.url(), streams.size()));
 333         // stream_hls_url_map will be updated in register_hls_url(), since it is not part
 334         // of the serialized state (it will always be picked out from the configuration).
 335         streams.emplace_back(new Stream(stream, data_fd));
 336         return streams.size() - 1;
 337 }
 338
 339 void Server::set_backlog_size(int stream_index, size_t new_size)
 340 {
 341         lock_guard<mutex> lock(mu);
 342         assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 343         streams[stream_index]->set_backlog_size(new_size);
 344 }
 345
 346 void Server::set_prebuffering_bytes(int stream_index, size_t new_amount)
 347 {
 348         lock_guard<mutex> lock(mu);
 349         assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 350         streams[stream_index]->prebuffering_bytes = new_amount;
 351 }
 352
 353 void Server::set_encoding(int stream_index, Stream::Encoding encoding)
 354 {
 355         lock_guard<mutex> lock(mu);
 356         assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 357         streams[stream_index]->encoding = encoding;
 358 }
 359
 360 void Server::set_src_encoding(int stream_index, Stream::Encoding encoding)
 361 {
 362         lock_guard<mutex> lock(mu);
 363         assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 364         streams[stream_index]->src_encoding = encoding;
 365 }
 366
 367 void Server::set_hls_frag_duration(int stream_index, unsigned hls_frag_duration)
 368 {
 369         lock_guard<mutex> lock(mu);
 370         assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 371         streams[stream_index]->hls_frag_duration = hls_frag_duration;
 372 }
 373
 374 void Server::set_hls_backlog_margin(int stream_index, size_t hls_backlog_margin)
 375 {
 376         lock_guard<mutex> lock(mu);
 377         assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 378         assert(hls_backlog_margin >= 0);
 379         assert(hls_backlog_margin < streams[stream_index]->backlog_size);
 380         streams[stream_index]->hls_backlog_margin = hls_backlog_margin;
 381 }
 382
 383 void Server::set_allow_origin(int stream_index, const string &allow_origin)
 384 {
 385         lock_guard<mutex> lock(mu);
 386         assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 387         streams[stream_index]->allow_origin = allow_origin;
 388 }
 389
 390 void Server::register_hls_url(int stream_index, const string &hls_url)
 391 {
 392         lock_guard<mutex> lock(mu);
 393         assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 394         assert(!hls_url.empty());
 395         stream_hls_url_map.insert(make_pair(hls_url, stream_index));
 396 }
 397
 398 void Server::set_header(int stream_index, const string &http_header, const string &stream_header)
 399 {
 400         lock_guard<mutex> lock(mu);
 401         assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 402         Stream *stream = streams[stream_index].get();
 403         stream->http_header = http_header;
 404
 405         if (stream_header != stream->stream_header) {
 406                 // We cannot start at any of the older starting points anymore,
 407                 // since they'd get the wrong header for the stream (not to mention
 408                 // that a changed header probably means the stream restarted,
 409                 // which means any client starting on the old one would probably
 410                 // stop playing properly at the change point). Next block
 411                 // should be a suitable starting point (if not, something is
 412                 // pretty strange), so it will fill up again soon enough.
 413                 stream->suitable_starting_points.clear();
 414
 415                 if (!stream->fragments.empty()) {
 416                         stream->fragments.clear();
 417                         ++stream->discontinuity_counter;
 418                         stream->clear_hls_playlist_cache();
 419                 }
 420         }
 421         stream->stream_header = stream_header;
 422 }
 423
 424 void Server::set_pacing_rate(int stream_index, uint32_t pacing_rate)
 425 {
 426         lock_guard<mutex> lock(mu);
 427         assert(clients.empty());
 428         assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 429         streams[stream_index]->pacing_rate = pacing_rate;
 430 }
 431
 432 void Server::add_gen204(const std::string &url, const std::string &allow_origin)
 433 {
 434         lock_guard<mutex> lock(mu);
 435         assert(clients.empty());
 436         ping_url_map[url] = allow_origin;
 437 }
 438
 439 void Server::create_tls_context_for_acceptor(const Acceptor *acceptor)
 440 {
 441         assert(acceptor->is_tls());
 442
 443         bool is_server = true;
 444         TLSContext *server_context = tls_create_context(is_server, TLS_V12);
 445
 446         const string &cert = acceptor->get_certificate_chain();
 447         int num_cert = tls_load_certificates(server_context, reinterpret_cast<const unsigned char *>(cert.data()), cert.size());
 448         assert(num_cert > 0);  // Should have been checked by config earlier.
 449
 450         const string &key = acceptor->get_private_key();
 451         int num_key = tls_load_private_key(server_context, reinterpret_cast<const unsigned char *>(key.data()), key.size());
 452         assert(num_key > 0);  // Should have been checked by config earlier.
 453
 454         tls_server_contexts.insert(make_pair(acceptor, server_context));
 455 }
 456
 457 void Server::add_data_deferred(int stream_index, const char *data, size_t bytes, uint16_t metacube_flags, const RationalPTS &pts)
 458 {
 459         assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
 460         streams[stream_index]->add_data_deferred(data, bytes, metacube_flags, pts);
 461 }
 462
 463 // See the .h file for postconditions after this function.
 464 void Server::process_client(Client *client)
 465 {
 466         switch (client->state) {
 467         case Client::READING_REQUEST: {
 468                 if (client->tls_context != nullptr) {
 469                         if (send_pending_tls_data(client)) {
 470                                 // send_pending_tls_data() hit postconditions #1 or #4.
 471                                 return;
 472                         }
 473                 }
 474
 475 read_request_again:
 476                 // Try to read more of the request.
 477                 char buf[1024];
 478                 int ret;
 479                 if (client->tls_context == nullptr) {
 480                         ret = read_nontls_data(client, buf, sizeof(buf));
 481                         if (ret == -1) {
 482                                 // read_nontls_data() hit postconditions #1 or #2.
 483                                 return;
 484                         }
 485                 } else {
 486                         ret = read_tls_data(client, buf, sizeof(buf));
 487                         if (ret == -1) {
 488                                 // read_tls_data() hit postconditions #1, #2 or #4.
 489                                 return;
 490                         }
 491                 }
 492
 493                 RequestParseStatus status = wait_for_double_newline(&client->request, buf, ret);
 494
 495                 switch (status) {
 496                 case RP_OUT_OF_SPACE:
 497                         log(WARNING, "[%s] Client sent overlong request!", client->remote_addr.c_str());
 498                         close_client(client);
 499                         return;
 500                 case RP_NOT_FINISHED_YET:
 501                         // OK, we don't have the entire header yet. Fine; we'll get it later.
 502                         // See if there's more data for us.
 503                         goto read_request_again;
 504                 case RP_EXTRA_DATA:
 505                         log(WARNING, "[%s] Junk data after request!", client->remote_addr.c_str());
 506                         close_client(client);
 507                         return;
 508                 case RP_FINISHED:
 509                         break;
 510                 }
 511
 512                 assert(status == RP_FINISHED);
 513
 514                 if (client->tls_context && !client->in_ktls_mode && tls_established(client->tls_context)) {
 515                         // We're ready to enter kTLS mode, unless we still have some
 516                         // handshake data to send (which then must be sent as non-kTLS).
 517                         if (send_pending_tls_data(client)) {
 518                                 // send_pending_tls_data() hit postconditions #1 or #4.
 519                                 return;
 520                         }
 521                         ret = tls_make_ktls(client->tls_context, client->sock);
 522                         if (ret < 0) {
 523                                 log_tls_error("tls_make_ktls", ret);
 524                                 close_client(client);
 525                                 return;
 526                         }
 527                         client->in_ktls_mode = true;
 528                 }
 529
 530                 int error_code = parse_request(client);
 531                 if (error_code == 200) {
 532                         if (client->serving_hls_playlist) {
 533                                 construct_hls_playlist(client);
 534                         } else {
 535                                 construct_stream_header(client);
 536                         }
 537                 } else if (error_code == 204) {
 538                         construct_204(client);
 539                 } else {
 540                         construct_error(client, error_code);
 541                 }
 542
 543                 // We've changed states, so fall through.
 544                 assert(client->state == Client::SENDING_SHORT_RESPONSE ||
 545                        client->state == Client::SENDING_HEADER);
 546         }
 547         case Client::SENDING_SHORT_RESPONSE:
 548         case Client::SENDING_HEADER: {
 549 sending_header_or_short_response_again:
 550                 int ret;
 551                 do {
 552                         ret = write(client->sock,
 553                                     client->header_or_short_response->data() + client->header_or_short_response_bytes_sent,
 554                                     client->header_or_short_response->size() - client->header_or_short_response_bytes_sent);
 555                 } while (ret == -1 && errno == EINTR);
 556
 557                 if (ret == -1 && errno == EAGAIN) {
 558                         // We're out of socket space, so now we're at the “low edge” of epoll's
 559                         // edge triggering. epoll will tell us when there is more room, so for now,
 560                         // just return.
 561                         // This is postcondition #4.
 562                         return;
 563                 }
 564
 565                 if (ret == -1) {
 566                         // Error! Postcondition #1.
 567                         log_perror("write");
 568                         close_client(client);
 569                         return;
 570                 }
 571
 572                 client->header_or_short_response_bytes_sent += ret;
 573                 assert(client->header_or_short_response_bytes_sent <= client->header_or_short_response->size());
 574
 575                 if (client->header_or_short_response_bytes_sent < client->header_or_short_response->size()) {
 576                         // We haven't sent all yet. Fine; go another round.
 577                         goto sending_header_or_short_response_again;
 578                 }
 579
 580                 // We're done sending the header or error! Clear it to release some memory.
 581                 client->header_or_short_response = nullptr;
 582                 client->header_or_short_response_holder.clear();
 583                 client->header_or_short_response_ref.reset();
 584
 585                 if (client->state == Client::SENDING_SHORT_RESPONSE) {
 586                         if (more_requests(client)) {
 587                                 // We're done sending the error, but should keep on reading new requests.
 588                                 goto read_request_again;
 589                         } else {
 590                                 // We're done sending the error, so now close.
 591                                 // This is postcondition #1.
 592                                 close_client(client);
 593                         }
 594                         return;
 595                 }
 596
 597                 Stream *stream = client->stream;
 598                 if (client->stream_pos == Client::STREAM_POS_AT_START) {
 599                         // Start sending from the beginning of the backlog.
 600                         client->stream_pos = min<size_t>(
 601                             stream->bytes_received - stream->backlog_size,
 602                             0);
 603                         client->state = Client::SENDING_DATA;
 604                         goto sending_data;
 605                 } else if (client->stream_pos_end != Client::STREAM_POS_NO_END) {
 606                         // We're sending a fragment, and should have all of it,
 607                         // so start sending right away.
 608                         assert(client->stream_pos >= 0);
 609                         client->state = Client::SENDING_DATA;
 610                         goto sending_data;
 611                 } else if (stream->prebuffering_bytes == 0) {
 612                         // Start sending from the first keyframe we get. In other
 613                         // words, we won't send any of the backlog, but we'll start
 614                         // sending immediately as we get the next keyframe block.
 615                         // Note that this is functionally identical to the next if branch,
 616                         // except that we save a binary search.
 617                         assert(client->stream_pos == Client::STREAM_POS_AT_END);
 618                         assert(client->stream_pos_end == Client::STREAM_POS_NO_END);
 619                         client->stream_pos = stream->bytes_received;
 620                         client->state = Client::WAITING_FOR_KEYFRAME;
 621                 } else {
 622                         // We're not going to send anything to the client before we have
 623                         // N bytes. However, this wait might be boring; we can just as well
 624                         // use it to send older data if we have it. We use lower_bound()
 625                         // so that we are conservative and never add extra latency over just
 626                         // waiting (assuming CBR or nearly so); otherwise, we could want e.g.
 627                         // 100 kB prebuffer but end up sending a 10 MB GOP.
 628                         assert(client->stream_pos == Client::STREAM_POS_AT_END);
 629                         assert(client->stream_pos_end == Client::STREAM_POS_NO_END);
 630                         deque<size_t>::const_iterator starting_point_it =
 631                                 lower_bound(stream->suitable_starting_points.begin(),
 632                                             stream->suitable_starting_points.end(),
 633                                             stream->bytes_received - stream->prebuffering_bytes);
 634                         if (starting_point_it == stream->suitable_starting_points.end()) {
 635                                 // None found. Just put us at the end, and then wait for the
 636                                 // first keyframe to appear.
 637                                 client->stream_pos = stream->bytes_received;
 638                                 client->state = Client::WAITING_FOR_KEYFRAME;
 639                         } else {
 640                                 client->stream_pos = *starting_point_it;
 641                                 client->state = Client::PREBUFFERING;
 642                                 goto prebuffering;
 643                         }
 644                 }
 645                 // Fall through.
 646         }
 647         case Client::WAITING_FOR_KEYFRAME: {
 648                 Stream *stream = client->stream;
 649                 if (stream->suitable_starting_points.empty() ||
 650                     client->stream_pos > stream->suitable_starting_points.back()) {
 651                         // We haven't received a keyframe since this stream started waiting,
 652                         // so keep on waiting for one.
 653                         // This is postcondition #3.
 654                         stream->put_client_to_sleep(client);
 655                         return;
 656                 }
 657                 client->stream_pos = stream->suitable_starting_points.back();
 658                 client->state = Client::PREBUFFERING;
 659                 // Fall through.
 660         }
 661         case Client::PREBUFFERING: {
 662 prebuffering:
 663                 Stream *stream = client->stream;
 664                 size_t bytes_to_send = stream->bytes_received - client->stream_pos;
 665                 assert(bytes_to_send <= stream->backlog_size);
 666                 if (bytes_to_send < stream->prebuffering_bytes) {
 667                         // We don't have enough bytes buffered to start this client yet.
 668                         // This is postcondition #3.
 669                         stream->put_client_to_sleep(client);
 670                         return;
 671                 }
 672                 client->state = Client::SENDING_DATA;
 673                 // Fall through.
 674         }
 675         case Client::SENDING_DATA: {
 676 sending_data:
 677                 skip_lost_data(client);
 678                 Stream *stream = client->stream;
 679
 680 sending_data_again:
 681                 size_t bytes_to_send;
 682                 if (client->stream_pos_end == Client::STREAM_POS_NO_END) {
 683                          bytes_to_send = stream->bytes_received - client->stream_pos;
 684                 } else {
 685                          bytes_to_send = client->stream_pos_end - client->stream_pos;
 686                 }
 687                 assert(bytes_to_send <= stream->backlog_size);
 688                 if (bytes_to_send == 0) {
 689                         if (client->stream_pos == client->stream_pos_end) {  // We have a definite end, and we're at it.
 690                                 if (more_requests(client)) {
 691                                         // We're done sending the fragment, but should keep on reading new requests.
 692                                         goto read_request_again;
 693                                 } else {
 694                                         // We're done sending the fragment, so now close.
 695                                         // This is postcondition #1.
 696                                         close_client(client);
 697                                 }
 698                         }
 699                         return;
 700                 }
 701
 702                 // See if we need to split across the circular buffer.
 703                 bool more_data = false;
 704                 if ((client->stream_pos % stream->backlog_size) + bytes_to_send > stream->backlog_size) {
 705                         bytes_to_send = stream->backlog_size - (client->stream_pos % stream->backlog_size);
 706                         more_data = true;
 707                 }
 708
 709                 ssize_t ret;
 710                 do {
 711                         off_t offset = client->stream_pos % stream->backlog_size;
 712                         ret = sendfile(client->sock, stream->data_fd, &offset, bytes_to_send);
 713                 } while (ret == -1 && errno == EINTR);
 714
 715                 if (ret == -1 && errno == EAGAIN) {
 716                         // We're out of socket space, so return; epoll will wake us up
 717                         // when there is more room.
 718                         // This is postcondition #4.
 719                         return;
 720                 }
 721                 if (ret == -1) {
 722                         // Error, close; postcondition #1.
 723                         log_perror("sendfile");
 724                         close_client(client);
 725                         return;
 726                 }
 727                 client->stream_pos += ret;
 728                 client->bytes_sent += ret;
 729
 730                 assert(client->stream_pos_end == Client::STREAM_POS_NO_END || client->stream_pos <= client->stream_pos_end);
 731                 if (client->stream_pos == client->stream_pos_end) {
 732                         goto sending_data_again;  // Will see that bytes_to_send == 0 and end.
 733                 } else if (client->stream_pos == stream->bytes_received) {
 734                         // We don't have any more data for this client, so put it to sleep.
 735                         // This is postcondition #3.
 736                         stream->put_client_to_sleep(client);
 737                 } else if (more_data && size_t(ret) == bytes_to_send) {
 738                         goto sending_data_again;
 739                 }
 740                 // We'll also get here for postcondition #4 (similar to the EAGAIN path above).
 741                 break;
 742         }
 743         default:
 744                 assert(false);
 745         }
 746 }
 747
 748 bool Server::send_pending_tls_data(Client *client)
 749 {
 750         // See if there's data from the TLS library to write.
 751         if (client->tls_data_to_send == nullptr) {
 752                 client->tls_data_to_send = tls_get_write_buffer(client->tls_context, &client->tls_data_left_to_send);
 753                 if (client->tls_data_to_send == nullptr) {
 754                         // Really no data to send.
 755                         return false;
 756                 }
 757         }
 758
 759 send_data_again:
 760         int ret;
 761         do {
 762                 ret = write(client->sock, client->tls_data_to_send, client->tls_data_left_to_send);
 763         } while (ret == -1 && errno == EINTR);
 764         assert(ret < 0 || size_t(ret) <= client->tls_data_left_to_send);
 765
 766         if (ret == -1 && errno == EAGAIN) {
 767                 // We're out of socket space, so now we're at the “low edge” of epoll's
 768                 // edge triggering. epoll will tell us when there is more room, so for now,
 769                 // just return.
 770                 // This is postcondition #4.
 771                 return true;
 772         }
 773         if (ret == -1) {
 774                 // Error! Postcondition #1.
 775                 log_perror("write");
 776                 close_client(client);
 777                 return true;
 778         }
 779         if (ret > 0 && size_t(ret) == client->tls_data_left_to_send) {
 780                 // All data has been sent, so we don't need to go to sleep.
 781                 tls_buffer_clear(client->tls_context);
 782                 client->tls_data_to_send = nullptr;
 783                 return false;
 784         }
 785
 786         // More data to send, so try again.
 787         client->tls_data_to_send += ret;
 788         client->tls_data_left_to_send -= ret;
 789         goto send_data_again;
 790 }
 791
 792 int Server::read_nontls_data(Client *client, char *buf, size_t max_size)
 793 {
 794         int ret;
 795         do {
 796                 ret = read(client->sock, buf, max_size);
 797         } while (ret == -1 && errno == EINTR);
 798
 799         if (ret == -1 && errno == EAGAIN) {
 800                 // No more data right now. Nothing to do.
 801                 // This is postcondition #2.
 802                 return -1;
 803         }
 804         if (ret == -1) {
 805                 log_perror("read");
 806                 close_client(client);
 807                 return -1;
 808         }
 809         if (ret == 0) {
 810                 // OK, the socket is closed.
 811                 close_client(client);
 812                 return -1;
 813         }
 814
 815         return ret;
 816 }
 817
 818 int Server::read_tls_data(Client *client, char *buf, size_t max_size)
 819 {
 820 read_again:
 821         int ret;
 822         do {
 823                 ret = read(client->sock, buf, max_size);
 824         } while (ret == -1 && errno == EINTR);
 825
 826         if (ret == -1 && errno == EAGAIN) {
 827                 // No more data right now. Nothing to do.
 828                 // This is postcondition #2.
 829                 return -1;
 830         }
 831         if (ret == -1) {
 832                 log_perror("read");
 833                 close_client(client);
 834                 return -1;
 835         }
 836         if (ret == 0) {
 837                 // OK, the socket is closed.
 838                 close_client(client);
 839                 return -1;
 840         }
 841
 842         // Give it to the TLS library.
 843         int err = tls_consume_stream(client->tls_context, reinterpret_cast<const unsigned char *>(buf), ret, nullptr);
 844         if (err < 0) {
 845                 log_tls_error("tls_consume_stream", err);
 846                 close_client(client);
 847                 return -1;
 848         }
 849         if (err == 0) {
 850                 // Not consumed any data. See if we can read more.
 851                 goto read_again;
 852         }
 853
 854         // Read any decrypted data available for us. (We can reuse buf, since it's free now.)
 855         ret = tls_read(client->tls_context, reinterpret_cast<unsigned char *>(buf), max_size);
 856         if (ret == 0) {
 857                 // No decrypted data for us yet, but there might be some more handshaking
 858                 // to send. Do that if needed, then look for more data.
 859                 if (send_pending_tls_data(client)) {
 860                         // send_pending_tls_data() hit postconditions #1 or #4.
 861                         return -1;
 862                 }
 863                 goto read_again;
 864         }
 865         if (ret < 0) {
 866                 log_tls_error("tls_read", ret);
 867                 close_client(client);
 868                 return -1;
 869         }
 870
 871         assert(ret > 0);
 872         return ret;
 873 }
 874
 875 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
 876 // but resync will be the mux's problem.
 877 void Server::skip_lost_data(Client *client)
 878 {
 879         Stream *stream = client->stream;
 880         if (stream == nullptr) {
 881                 return;
 882         }
 883         size_t bytes_to_send = stream->bytes_received - client->stream_pos;
 884         if (bytes_to_send > stream->backlog_size) {
 885                 size_t bytes_lost = bytes_to_send - stream->backlog_size;
 886                 client->bytes_lost += bytes_lost;
 887                 ++client->num_loss_events;
 888                 if (!client->close_after_response) {
 889                         assert(client->stream_pos_end != Client::STREAM_POS_NO_END);
 890
 891                         // We've already sent a Content-length, so we can't just skip data.
 892                         // Close the connection immediately and hope the other side
 893                         // is able to figure out that there was an error and it needs to skip.
 894                         client->close_after_response = true;
 895                         client->stream_pos = client->stream_pos_end;
 896                 } else {
 897                         client->stream_pos = stream->bytes_received - stream->backlog_size;
 898                 }
 899         }
 900 }
 901
 902 int Server::parse_request(Client *client)
 903 {
 904         vector<string> lines = split_lines(client->request);
 905         client->request.clear();
 906         if (lines.empty()) {
 907                 return 400;  // Bad request (empty).
 908         }
 909
 910         // Parse the headers, for logging purposes.
 911         // TODO: Case-insensitivity.
 912         multimap<string, string> headers = extract_headers(lines, client->remote_addr);
 913         multimap<string, string>::const_iterator referer_it = headers.find("Referer");
 914         if (referer_it != headers.end()) {
 915                 client->referer = referer_it->second;
 916         }
 917         multimap<string, string>::const_iterator user_agent_it = headers.find("User-Agent");
 918         if (user_agent_it != headers.end()) {
 919                 client->user_agent = user_agent_it->second;
 920         }
 921
 922         vector<string> request_tokens = split_tokens(lines[0]);
 923         if (request_tokens.size() < 3) {
 924                 return 400;  // Bad request (empty).
 925         }
 926         if (request_tokens[0] != "GET") {
 927                 return 400;  // Should maybe be 405 instead?
 928         }
 929
 930         string url = request_tokens[1];
 931         client->url = url;
 932         if (url.size() > 8 && url.find("?backlog") == url.size() - 8) {
 933                 client->stream_pos = Client::STREAM_POS_AT_START;
 934                 url = url.substr(0, url.size() - 8);
 935         } else {
 936                 size_t pos = url.find("?frag=");
 937                 if (pos != string::npos) {
 938                         // Parse an endpoint of the type /stream.mp4?frag=1234-5678.
 939                         const char *ptr = url.c_str() + pos + 6;
 940
 941                         // "?frag=header" is special.
 942                         if (strcmp(ptr, "header") == 0) {
 943                                 client->stream_pos = Client::STREAM_POS_HEADER_ONLY;
 944                                 client->stream_pos_end = -1;
 945                         } else {
 946                                 char *endptr;
 947                                 long long frag_start = strtol(ptr, &endptr, 10);
 948                                 if (ptr == endptr || frag_start < 0 || frag_start == LLONG_MAX) {
 949                                         return 400;  // Bad request.
 950                                 }
 951                                 if (*endptr != '-') {
 952                                         return 400;  // Bad request.
 953                                 }
 954                                 ptr = endptr + 1;
 955
 956                                 long long frag_end = strtol(ptr, &endptr, 10);
 957                                 if (ptr == endptr || frag_end < frag_start || frag_end == LLONG_MAX) {
 958                                         return 400;  // Bad request.
 959                                 }
 960
 961                                 if (*endptr != '\0') {
 962                                         return 400;  // Bad request.
 963                                 }
 964
 965                                 client->stream_pos = frag_start;
 966                                 client->stream_pos_end = frag_end;
 967                         }
 968                         url = url.substr(0, pos);
 969                 } else {
 970                         client->stream_pos = -1;
 971                         client->stream_pos_end = -1;
 972                 }
 973         }
 974
 975         // Figure out if we're supposed to close the socket after we've delivered the response.
 976         string protocol = request_tokens[2];
 977         if (protocol.find("HTTP/") != 0) {
 978                 return 400;  // Bad request.
 979         }
 980         client->close_after_response = false;
 981         client->http_11 = true;
 982         if (protocol == "HTTP/1.0") {
 983                 // No persistent connections.
 984                 client->close_after_response = true;
 985                 client->http_11 = false;
 986         } else {
 987                 multimap<string, string>::const_iterator connection_it = headers.find("Connection");
 988                 if (connection_it != headers.end() && connection_it->second == "close") {
 989                         client->close_after_response = true;
 990                 }
 991         }
 992
 993         map<string, int>::const_iterator stream_url_map_it = stream_url_map.find(url);
 994         if (stream_url_map_it != stream_url_map.end()) {
 995                 // Serve a regular stream..
 996                 client->stream = streams[stream_url_map_it->second].get();
 997                 client->serving_hls_playlist = false;
 998         } else {
 999                 map<string, int>::const_iterator stream_hls_url_map_it = stream_hls_url_map.find(url);
1000                 if (stream_hls_url_map_it != stream_hls_url_map.end()) {
1001                         // Serve HLS playlist.
1002                         client->stream = streams[stream_hls_url_map_it->second].get();
1003                         client->serving_hls_playlist = true;
1004                 } else {
1005                         map<string, string>::const_iterator ping_url_map_it = ping_url_map.find(url);
1006                         if (ping_url_map_it == ping_url_map.end()) {
1007                                 return 404;  // Not found.
1008                         } else {
1009                                 // Serve a ping (204 no error).
1010                                 return 204;
1011                         }
1012                 }
1013         }
1014
1015         Stream *stream = client->stream;
1016         if (stream->http_header.empty()) {
1017                 return 503;  // Service unavailable.
1018         }
1019
1020         if (client->serving_hls_playlist) {
1021                 if (stream->encoding == Stream::STREAM_ENCODING_METACUBE) {
1022                         // This doesn't make any sense, and is hard to implement, too.
1023                         return 404;
1024                 } else {
1025                         return 200;
1026                 }
1027         }
1028
1029         if (client->stream_pos_end == Client::STREAM_POS_NO_END) {
1030                 // This stream won't end, so we don't have a content-length,
1031                 // and can just as well tell the client it's Connection: close
1032                 // (otherwise, we'd have to implement chunking TE for no good reason).
1033                 client->close_after_response = true;
1034         } else {
1035                 if (stream->encoding == Stream::STREAM_ENCODING_METACUBE) {
1036                         // This doesn't make any sense, and is hard to implement, too.
1037                         return 416;  // Range not satisfiable.
1038                 }
1039
1040                 // Check that we have the requested fragment in our backlog.
1041                 size_t buffer_end = stream->bytes_received;
1042                 size_t buffer_start = (buffer_end <= stream->backlog_size) ? 0 : buffer_end - stream->backlog_size;
1043
1044                 if (client->stream_pos_end > buffer_end ||
1045                     client->stream_pos < buffer_start) {
1046                         return 416;  // Range not satisfiable.
1047                 }
1048         }
1049
1050         client->stream = stream;
1051         if (setsockopt(client->sock, SOL_SOCKET, SO_MAX_PACING_RATE, &client->stream->pacing_rate, sizeof(client->stream->pacing_rate)) == -1) {
1052                 if (client->stream->pacing_rate != ~0U) {
1053                         log_perror("setsockopt(SO_MAX_PACING_RATE)");
1054                 }
1055         }
1056         client->request.clear();
1057
1058         return 200;  // OK!
1059 }
1060
1061 void Server::construct_stream_header(Client *client)
1062 {
1063         Stream *stream = client->stream;
1064         string response = stream->http_header;
1065         if (client->stream_pos == Client::STREAM_POS_HEADER_ONLY) {
1066                 char buf[64];
1067                 snprintf(buf, sizeof(buf), "Content-length: %zu\r\n", stream->stream_header.size());
1068                 response.append(buf);
1069         } else if (client->stream_pos_end != Client::STREAM_POS_NO_END) {
1070                 char buf[64];
1071                 snprintf(buf, sizeof(buf), "Content-length: %zu\r\n", client->stream_pos_end - client->stream_pos);
1072                 response.append(buf);
1073         }
1074         if (client->http_11) {
1075                 assert(response.find("HTTP/1.0") == 0);
1076                 response[7] = '1';  // Change to HTTP/1.1.
1077                 if (client->close_after_response) {
1078                         response.append("Connection: close\r\n");
1079                 }
1080         } else {
1081                 assert(client->close_after_response);
1082         }
1083         if (!stream->allow_origin.empty()) {
1084                 response.append("Access-Control-Allow-Origin: ");
1085                 response.append(stream->allow_origin);
1086                 response.append("\r\n");
1087         }
1088         if (stream->encoding == Stream::STREAM_ENCODING_RAW) {
1089                 response.append("\r\n");
1090         } else if (stream->encoding == Stream::STREAM_ENCODING_METACUBE) {
1091                 response.append("Content-encoding: metacube\r\n\r\n");
1092                 if (!stream->stream_header.empty()) {
1093                         metacube2_block_header hdr;
1094                         memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
1095                         hdr.size = htonl(stream->stream_header.size());
1096                         hdr.flags = htons(METACUBE_FLAGS_HEADER);
1097                         hdr.csum = htons(metacube2_compute_crc(&hdr));
1098                         response.append(string(reinterpret_cast<char *>(&hdr), sizeof(hdr)));
1099                 }
1100         } else {
1101                 assert(false);
1102         }
1103         if (client->stream_pos == Client::STREAM_POS_HEADER_ONLY) {
1104                 client->state = Client::SENDING_SHORT_RESPONSE;
1105                 response.append(stream->stream_header);
1106         } else {
1107                 client->state = Client::SENDING_HEADER;
1108                 if (client->stream_pos_end == Client::STREAM_POS_NO_END) {  // Fragments don't contain stream headers.
1109                         response.append(stream->stream_header);
1110                 }
1111         }
1112
1113         client->header_or_short_response_holder = move(response);
1114         client->header_or_short_response = &client->header_or_short_response_holder;
1115
1116         // Switch states.
1117         change_epoll_events(client, EPOLLOUT | EPOLLET | EPOLLRDHUP);
1118 }
1119
1120 void Server::construct_error(Client *client, int error_code)
1121 {
1122         char error[256];
1123         if (client->http_11 && client->close_after_response) {
1124                 snprintf(error, sizeof(error),
1125                         "HTTP/1.1 %d Error\r\nContent-type: text/plain\r\nConnection: close\r\n\r\nSomething went wrong. Sorry.\r\n",
1126                         error_code);
1127         } else {
1128                 snprintf(error, sizeof(error),
1129                         "HTTP/1.%d %d Error\r\nContent-type: text/plain\r\nContent-length: 30\r\n\r\nSomething went wrong. Sorry.\r\n",
1130                         client->http_11, error_code);
1131         }
1132         client->header_or_short_response_holder = error;
1133         client->header_or_short_response = &client->header_or_short_response_holder;
1134
1135         // Switch states.
1136         client->state = Client::SENDING_SHORT_RESPONSE;
1137         change_epoll_events(client, EPOLLOUT | EPOLLET | EPOLLRDHUP);
1138 }
1139
1140 void Server::construct_hls_playlist(Client *client)
1141 {
1142         Stream *stream = client->stream;
1143         shared_ptr<const string> *cache;
1144         if (client->http_11) {
1145                 if (client->close_after_response) {
1146                         cache = &stream->hls_playlist_http11_close;
1147                 } else {
1148                         cache = &stream->hls_playlist_http11_persistent;
1149                 }
1150         } else {
1151                 assert(client->close_after_response);
1152                 cache = &stream->hls_playlist_http10;
1153         }
1154
1155         if (*cache == nullptr) {
1156                 *cache = stream->generate_hls_playlist(client->http_11, client->close_after_response);
1157         }
1158         client->header_or_short_response_ref = *cache;
1159         client->header_or_short_response = cache->get();
1160
1161         // Switch states.
1162         client->state = Client::SENDING_SHORT_RESPONSE;
1163         change_epoll_events(client, EPOLLOUT | EPOLLET | EPOLLRDHUP);
1164 }
1165
1166 void Server::construct_204(Client *client)
1167 {
1168         map<string, string>::const_iterator ping_url_map_it = ping_url_map.find(client->url);
1169         assert(ping_url_map_it != ping_url_map.end());
1170
1171         string response;
1172         if (client->http_11) {
1173                 response = "HTTP/1.1 204 No Content\r\n";
1174                 if (client->close_after_response) {
1175                         response.append("Connection: close\r\n");
1176                 }
1177         } else {
1178                 response = "HTTP/1.0 204 No Content\r\n";
1179                 assert(client->close_after_response);
1180         }
1181         if (!ping_url_map_it->second.empty()) {
1182                 response.append("Access-Control-Allow-Origin: ");
1183                 response.append(ping_url_map_it->second);
1184                 response.append("\r\n");
1185         }
1186         response.append("\r\n");
1187
1188         client->header_or_short_response_holder = move(response);
1189         client->header_or_short_response = &client->header_or_short_response_holder;
1190
1191         // Switch states.
1192         client->state = Client::SENDING_SHORT_RESPONSE;
1193         change_epoll_events(client, EPOLLOUT | EPOLLET | EPOLLRDHUP);
1194 }
1195
1196 template<class T>
1197 void delete_from(vector<T> *v, T elem)
1198 {
1199         typename vector<T>::iterator new_end = remove(v->begin(), v->end(), elem);
1200         v->erase(new_end, v->end());
1201 }
1202
1203 void Server::close_client(Client *client)
1204 {
1205         if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, nullptr) == -1) {
1206                 log_perror("epoll_ctl(EPOLL_CTL_DEL)");
1207                 exit(1);
1208         }
1209
1210         // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
1211         if (client->stream != nullptr) {
1212                 delete_from(&client->stream->sleeping_clients, client);
1213                 delete_from(&client->stream->to_process, client);
1214         }
1215
1216         if (client->tls_context) {
1217                 tls_destroy_context(client->tls_context);
1218         }
1219
1220         // Log to access_log.
1221         access_log->write(client->get_stats());
1222
1223         // Bye-bye!
1224         safe_close(client->sock);
1225
1226         clients.erase(client->sock);
1227 }
1228
1229 void Server::change_epoll_events(Client *client, uint32_t events)
1230 {
1231         epoll_event ev;
1232         ev.events = events;
1233         ev.data.ptr = client;
1234
1235         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
1236                 log_perror("epoll_ctl(EPOLL_CTL_MOD)");
1237                 exit(1);
1238         }
1239 }
1240
1241 bool Server::more_requests(Client *client)
1242 {
1243         if (client->close_after_response) {
1244                 return false;
1245         }
1246
1247         // Log to access_log.
1248         access_log->write(client->get_stats());
1249
1250         // Switch states and reset the parsers. We don't reset statistics.
1251         client->state = Client::READING_REQUEST;
1252         client->url.clear();
1253         client->stream = NULL;
1254         client->header_or_short_response = nullptr;
1255         client->header_or_short_response_holder.clear();
1256         client->header_or_short_response_ref.reset();
1257         client->header_or_short_response_bytes_sent = 0;
1258
1259         change_epoll_events(client, EPOLLIN | EPOLLET | EPOLLRDHUP);  // No TLS handshake, so no EPOLLOUT needed.
1260
1261         return true;
1262 }
1263
1264 void Server::process_queued_data()
1265 {
1266         {
1267                 lock_guard<mutex> lock(queued_clients_mutex);
1268
1269                 for (const pair<int, Acceptor *> &id_and_acceptor : queued_add_clients) {
1270                         add_client(id_and_acceptor.first, id_and_acceptor.second);
1271                 }
1272                 queued_add_clients.clear();
1273         }
1274
1275         for (unique_ptr<Stream> &stream : streams) {
1276                 stream->process_queued_data();
1277         }
1278 }