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

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdint.h>
   4 #include <assert.h>
   5 #include <arpa/inet.h>
   6 #include <curl/curl.h>
   7 #include <sys/socket.h>
   8 #include <pthread.h>
   9 #include <sys/types.h>
  10 #include <sys/ioctl.h>
  11 #include <sys/epoll.h>
  12 #include <errno.h>
  13 #include <vector>
  14 #include <string>
  15 #include <map>
  16 #include <algorithm>
  17
  18 #include "metacube.h"
  19 #include "server.h"
  20 #include "mutexlock.h"
  21 #include "parse.h"
  22 #include "state.pb.h"
  23
  24 using namespace std;
  25
  26 Client::Client(int sock)
  27         : sock(sock),
  28           state(Client::READING_REQUEST),
  29           stream(NULL),
  30           header_or_error_bytes_sent(0),
  31           bytes_sent(0)
  32 {
  33         request.reserve(1024);
  34 }
  35
  36 Client::Client(const ClientProto &serialized, Stream *stream)
  37         : sock(serialized.sock()),
  38           state(State(serialized.state())),
  39           request(serialized.request()),
  40           stream_id(serialized.stream_id()),
  41           stream(stream),
  42           header_or_error(serialized.header_or_error()),
  43           header_or_error_bytes_sent(serialized.header_or_error_bytes_sent()),
  44           bytes_sent(serialized.bytes_sent())
  45 {
  46 }
  47
  48 ClientProto Client::serialize() const
  49 {
  50         ClientProto serialized;
  51         serialized.set_sock(sock);
  52         serialized.set_state(state);
  53         serialized.set_request(request);
  54         serialized.set_stream_id(stream_id);
  55         serialized.set_header_or_error(header_or_error);
  56         serialized.set_header_or_error_bytes_sent(serialized.header_or_error_bytes_sent());
  57         serialized.set_bytes_sent(bytes_sent);
  58         return serialized;
  59 }
  60
  61 Stream::Stream(const string &stream_id)
  62         : stream_id(stream_id),
  63           data(new char[BACKLOG_SIZE]),
  64           data_size(0)
  65 {
  66         memset(data, 0, BACKLOG_SIZE);
  67 }
  68
  69 Stream::~Stream()
  70 {
  71         delete[] data;
  72 }
  73
  74 Stream::Stream(const StreamProto &serialized)
  75         : stream_id(serialized.stream_id()),
  76           header(serialized.header()),
  77           data(new char[BACKLOG_SIZE]),
  78           data_size(serialized.data_size())
  79 {
  80         assert(serialized.data().size() == BACKLOG_SIZE);
  81         memcpy(data, serialized.data().data(), BACKLOG_SIZE);
  82 }
  83
  84 StreamProto Stream::serialize() const
  85 {
  86         StreamProto serialized;
  87         serialized.set_header(header);
  88         serialized.set_data(string(data, data + BACKLOG_SIZE));
  89         serialized.set_data_size(data_size);
  90         serialized.set_stream_id(stream_id);
  91         return serialized;
  92 }
  93
  94 void Stream::put_client_to_sleep(Client *client)
  95 {
  96         sleeping_clients.push_back(client);
  97 }
  98
  99 void Stream::wake_up_all_clients()
 100 {
 101         if (to_process.empty()) {
 102                 swap(sleeping_clients, to_process);
 103         } else {
 104                 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
 105                 sleeping_clients.clear();
 106         }
 107 }
 108
 109 Server::Server()
 110 {
 111         pthread_mutex_init(&mutex, NULL);
 112         pthread_mutex_init(&queued_data_mutex, NULL);
 113
 114         epoll_fd = epoll_create(1024);  // Size argument is ignored.
 115         if (epoll_fd == -1) {
 116                 perror("epoll_fd");
 117                 exit(1);
 118         }
 119 }
 120
 121 Server::~Server()
 122 {
 123         int ret;
 124         do {
 125                 ret = close(epoll_fd);
 126         } while (ret == -1 && errno == EINTR);
 127
 128         if (ret == -1) {
 129                 perror("close(epoll_fd)");
 130         }
 131 }
 132
 133 void Server::run()
 134 {
 135         should_stop = false;
 136
 137         // Joinable is already the default, but it's good to be certain.
 138         pthread_attr_t attr;
 139         pthread_attr_init(&attr);
 140         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
 141         pthread_create(&worker_thread, &attr, Server::do_work_thunk, this);
 142 }
 143
 144 void Server::stop()
 145 {
 146         {
 147                 MutexLock lock(&mutex);
 148                 should_stop = true;
 149         }
 150
 151         if (pthread_join(worker_thread, NULL) == -1) {
 152                 perror("pthread_join");
 153                 exit(1);
 154         }
 155 }
 156
 157 void *Server::do_work_thunk(void *arg)
 158 {
 159         Server *server = static_cast<Server *>(arg);
 160         server->do_work();
 161         return NULL;
 162 }
 163
 164 void Server::do_work()
 165 {
 166         for ( ;; ) {
 167                 int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
 168                 if (nfds == -1 && errno == EINTR) {
 169                         continue;
 170                 }
 171                 if (nfds == -1) {
 172                         perror("epoll_wait");
 173                         exit(1);
 174                 }
 175
 176                 MutexLock lock(&mutex);  // We release the mutex between iterations.
 177
 178                 if (should_stop) {
 179                         return;
 180                 }
 181
 182                 process_queued_data();
 183
 184                 for (int i = 0; i < nfds; ++i) {
 185                         int fd = events[i].data.fd;
 186                         assert(clients.count(fd) != 0);
 187                         Client *client = &clients[fd];
 188
 189                         if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
 190                                 close_client(client);
 191                                 continue;
 192                         }
 193
 194                         process_client(client);
 195                 }
 196
 197                 for (map<string, Stream *>::iterator stream_it = streams.begin();
 198                      stream_it != streams.end();
 199                      ++stream_it) {
 200                         Stream *stream = stream_it->second;
 201                         for (size_t i = 0; i < stream->to_process.size(); ++i) {
 202                                 process_client(stream->to_process[i]);
 203                         }
 204                         stream->to_process.clear();
 205                 }
 206         }
 207 }
 208
 209 CubemapStateProto Server::serialize()
 210 {
 211         // We don't serialize anything queued, so empty the queues.
 212         process_queued_data();
 213
 214         CubemapStateProto serialized;
 215         for (map<int, Client>::const_iterator client_it = clients.begin();
 216              client_it != clients.end();
 217              ++client_it) {
 218                 serialized.add_clients()->MergeFrom(client_it->second.serialize());
 219         }
 220         for (map<string, Stream *>::const_iterator stream_it = streams.begin();
 221              stream_it != streams.end();
 222              ++stream_it) {
 223                 serialized.add_streams()->MergeFrom(stream_it->second->serialize());
 224         }
 225         return serialized;
 226 }
 227
 228 void Server::add_client_deferred(int sock)
 229 {
 230         MutexLock lock(&queued_data_mutex);
 231         queued_add_clients.push_back(sock);
 232 }
 233
 234 void Server::add_client(int sock)
 235 {
 236         clients.insert(make_pair(sock, Client(sock)));
 237
 238         // Start listening on data from this socket.
 239         epoll_event ev;
 240         ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
 241         ev.data.u64 = 0;  // Keep Valgrind happy.
 242         ev.data.fd = sock;
 243         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
 244                 perror("epoll_ctl(EPOLL_CTL_ADD)");
 245                 exit(1);
 246         }
 247
 248         process_client(&clients[sock]);
 249 }
 250
 251 void Server::add_client_from_serialized(const ClientProto &client)
 252 {
 253         MutexLock lock(&mutex);
 254         Stream *stream = find_stream(client.stream_id());
 255         clients.insert(make_pair(client.sock(), Client(client, stream)));
 256         Client *client_ptr = &clients[client.sock()];
 257
 258         // Start listening on data from this socket.
 259         epoll_event ev;
 260         if (client.state() == Client::READING_REQUEST) {
 261                 ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
 262         } else {
 263                 // If we don't have more data for this client, we'll be putting it into
 264                 // the sleeping array again soon.
 265                 ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
 266         }
 267         ev.data.u64 = 0;  // Keep Valgrind happy.
 268         ev.data.fd = client.sock();
 269         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, client.sock(), &ev) == -1) {
 270                 perror("epoll_ctl(EPOLL_CTL_ADD)");
 271                 exit(1);
 272         }
 273
 274         if (client_ptr->state == Client::SENDING_DATA &&
 275             client_ptr->bytes_sent == client_ptr->stream->data_size) {
 276                 client_ptr->stream->put_client_to_sleep(client_ptr);
 277         } else {
 278                 process_client(client_ptr);
 279         }
 280 }
 281
 282 void Server::add_stream(const string &stream_id)
 283 {
 284         MutexLock lock(&mutex);
 285         streams.insert(make_pair(stream_id, new Stream(stream_id)));
 286 }
 287
 288 void Server::add_stream_from_serialized(const StreamProto &stream)
 289 {
 290         MutexLock lock(&mutex);
 291         streams.insert(make_pair(stream.stream_id(), new Stream(stream)));
 292 }
 293
 294 void Server::set_header(const string &stream_id, const string &header)
 295 {
 296         MutexLock lock(&mutex);
 297         find_stream(stream_id)->header = header;
 298
 299         // If there are clients we haven't sent anything to yet, we should give
 300         // them the header, so push back into the SENDING_HEADER state.
 301         for (map<int, Client>::iterator client_it = clients.begin();
 302              client_it != clients.end();
 303              ++client_it) {
 304                 Client *client = &client_it->second;
 305                 if (client->state == Client::SENDING_DATA &&
 306                     client->bytes_sent == 0) {
 307                         construct_header(client);
 308                 }
 309         }
 310 }
 311
 312 void Server::add_data_deferred(const string &stream_id, const char *data, size_t bytes)
 313 {
 314         MutexLock lock(&queued_data_mutex);
 315         queued_data[stream_id].append(string(data, data + bytes));
 316 }
 317
 318 void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 319 {
 320         Stream *stream = find_stream(stream_id);
 321         size_t pos = stream->data_size % BACKLOG_SIZE;
 322         stream->data_size += bytes;
 323
 324         if (pos + bytes > BACKLOG_SIZE) {
 325                 size_t to_copy = BACKLOG_SIZE - pos;
 326                 memcpy(stream->data + pos, data, to_copy);
 327                 data += to_copy;
 328                 bytes -= to_copy;
 329                 pos = 0;
 330         }
 331
 332         memcpy(stream->data + pos, data, bytes);
 333         stream->wake_up_all_clients();
 334 }
 335
 336 // See the .h file for postconditions after this function.
 337 void Server::process_client(Client *client)
 338 {
 339         switch (client->state) {
 340         case Client::READING_REQUEST: {
 341 read_request_again:
 342                 // Try to read more of the request.
 343                 char buf[1024];
 344                 int ret;
 345                 do {
 346                         ret = read(client->sock, buf, sizeof(buf));
 347                 } while (ret == -1 && errno == EINTR);
 348
 349                 if (ret == -1 && errno == EAGAIN) {
 350                         // No more data right now. Nothing to do.
 351                         // This is postcondition #2.
 352                         return;
 353                 }
 354                 if (ret == -1) {
 355                         perror("read");
 356                         close_client(client);
 357                         return;
 358                 }
 359                 if (ret == 0) {
 360                         // OK, the socket is closed.
 361                         close_client(client);
 362                         return;
 363                 }
 364
 365                 // Guard against overlong requests gobbling up all of our space.
 366                 if (client->request.size() + ret > MAX_CLIENT_REQUEST) {
 367                         fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
 368                         close_client(client);
 369                         return;
 370                 }
 371
 372                 // See if we have \r\n\r\n anywhere in the request. We start three bytes
 373                 // before what we just appended, in case we just got the final character.
 374                 size_t existing_req_bytes = client->request.size();
 375                 client->request.append(string(buf, buf + ret));
 376
 377                 size_t start_at = (existing_req_bytes >= 3 ? existing_req_bytes - 3 : 0);
 378                 const char *ptr = reinterpret_cast<char *>(
 379                         memmem(client->request.data() + start_at, client->request.size() - start_at,
 380                                "\r\n\r\n", 4));
 381                 if (ptr == NULL) {
 382                         // OK, we don't have the entire header yet. Fine; we'll get it later.
 383                         // See if there's more data for us.
 384                         goto read_request_again;
 385                 }
 386
 387                 if (ptr != client->request.data() + client->request.size() - 4) {
 388                         fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
 389                         close_client(client);
 390                         return;
 391                 }
 392
 393                 int error_code = parse_request(client);
 394                 if (error_code == 200) {
 395                         construct_header(client);
 396                 } else {
 397                         construct_error(client, error_code);
 398                 }
 399
 400                 // We've changed states, so fall through.
 401                 assert(client->state == Client::SENDING_ERROR ||
 402                        client->state == Client::SENDING_HEADER);
 403         }
 404         case Client::SENDING_ERROR:
 405         case Client::SENDING_HEADER: {
 406 sending_header_or_error_again:
 407                 int ret;
 408                 do {
 409                         ret = write(client->sock,
 410                                     client->header_or_error.data() + client->header_or_error_bytes_sent,
 411                                     client->header_or_error.size() - client->header_or_error_bytes_sent);
 412                 } while (ret == -1 && errno == EINTR);
 413
 414                 if (ret == -1 && errno == EAGAIN) {
 415                         // We're out of socket space, so now we're at the “low edge” of epoll's
 416                         // edge triggering. epoll will tell us when there is more room, so for now,
 417                         // just return.
 418                         // This is postcondition #4.
 419                         return;
 420                 }
 421
 422                 if (ret == -1) {
 423                         // Error! Postcondition #1.
 424                         perror("write");
 425                         close_client(client);
 426                         return;
 427                 }
 428
 429                 client->header_or_error_bytes_sent += ret;
 430                 assert(client->header_or_error_bytes_sent <= client->header_or_error.size());
 431
 432                 if (client->header_or_error_bytes_sent < client->header_or_error.size()) {
 433                         // We haven't sent all yet. Fine; go another round.
 434                         goto sending_header_or_error_again;
 435                 }
 436
 437                 // We're done sending the header or error! Clear it to release some memory.
 438                 client->header_or_error.clear();
 439
 440                 if (client->state == Client::SENDING_ERROR) {
 441                         // We're done sending the error, so now close.
 442                         // This is postcondition #1.
 443                         close_client(client);
 444                         return;
 445                 }
 446
 447                 // Start sending from the end. In other words, we won't send any of the backlog,
 448                 // but we'll start sending immediately as we get data.
 449                 // This is postcondition #3.
 450                 client->state = Client::SENDING_DATA;
 451                 client->bytes_sent = client->stream->data_size;
 452                 client->stream->put_client_to_sleep(client);
 453                 return;
 454         }
 455         case Client::SENDING_DATA: {
 456                 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
 457                 // but resync will be the mux's problem.
 458                 Stream *stream = client->stream;
 459                 size_t bytes_to_send = stream->data_size - client->bytes_sent;
 460                 if (bytes_to_send == 0) {
 461                         return;
 462                 }
 463                 if (bytes_to_send > BACKLOG_SIZE) {
 464                         fprintf(stderr, "WARNING: fd %d lost %lld bytes, maybe too slow connection\n",
 465                                 client->sock,
 466                                 (long long int)(bytes_to_send - BACKLOG_SIZE));
 467                         client->bytes_sent = stream->data_size - BACKLOG_SIZE;
 468                         bytes_to_send = BACKLOG_SIZE;
 469                 }
 470
 471                 // See if we need to split across the circular buffer.
 472                 ssize_t ret;
 473                 if ((client->bytes_sent % BACKLOG_SIZE) + bytes_to_send > BACKLOG_SIZE) {
 474                         size_t bytes_first_part = BACKLOG_SIZE - (client->bytes_sent % BACKLOG_SIZE);
 475
 476                         iovec iov[2];
 477                         iov[0].iov_base = const_cast<char *>(stream->data + (client->bytes_sent % BACKLOG_SIZE));
 478                         iov[0].iov_len = bytes_first_part;
 479
 480                         iov[1].iov_base = const_cast<char *>(stream->data);
 481                         iov[1].iov_len = bytes_to_send - bytes_first_part;
 482
 483                         do {
 484                                 ret = writev(client->sock, iov, 2);
 485                         } while (ret == -1 && errno == EINTR);
 486                 } else {
 487                         do {
 488                                 ret = write(client->sock,
 489                                             stream->data + (client->bytes_sent % BACKLOG_SIZE),
 490                                             bytes_to_send);
 491                         } while (ret == -1 && errno == EINTR);
 492                 }
 493                 if (ret == -1 && errno == EAGAIN) {
 494                         // We're out of socket space, so return; epoll will wake us up
 495                         // when there is more room.
 496                         // This is postcondition #4.
 497                         return;
 498                 }
 499                 if (ret == -1) {
 500                         // Error, close; postcondition #1.
 501                         perror("write/writev");
 502                         close_client(client);
 503                         return;
 504                 }
 505                 client->bytes_sent += ret;
 506
 507                 if (client->bytes_sent == stream->data_size) {
 508                         // We don't have any more data for this client, so put it to sleep.
 509                         // This is postcondition #3.
 510                         stream->put_client_to_sleep(client);
 511                 } else {
 512                         // XXX: Do we need to go another round here to explicitly
 513                         // get the EAGAIN?
 514                 }
 515                 break;
 516         }
 517         default:
 518                 assert(false);
 519         }
 520 }
 521
 522 int Server::parse_request(Client *client)
 523 {
 524         vector<string> lines = split_lines(client->request);
 525         if (lines.empty()) {
 526                 return 400;  // Bad request (empty).
 527         }
 528
 529         vector<string> request_tokens = split_tokens(lines[0]);
 530         if (request_tokens.size() < 2) {
 531                 return 400;  // Bad request (empty).
 532         }
 533         if (request_tokens[0] != "GET") {
 534                 return 400;  // Should maybe be 405 instead?
 535         }
 536         if (streams.count(request_tokens[1]) == 0) {
 537                 return 404;  // Not found.
 538         }
 539
 540         client->stream_id = request_tokens[1];
 541         client->stream = find_stream(client->stream_id);
 542         client->request.clear();
 543
 544         return 200;  // OK!
 545 }
 546
 547 void Server::construct_header(Client *client)
 548 {
 549         client->header_or_error = "HTTP/1.0 200 OK\r\nContent-type: video/x-flv\r\nCache-Control: no-cache\r\n\r\n" +
 550                 find_stream(client->stream_id)->header;
 551
 552         // Switch states.
 553         client->state = Client::SENDING_HEADER;
 554
 555         epoll_event ev;
 556         ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
 557         ev.data.u64 = 0;  // Keep Valgrind happy.
 558         ev.data.fd = client->sock;
 559
 560         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 561                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 562                 exit(1);
 563         }
 564 }
 565
 566 void Server::construct_error(Client *client, int error_code)
 567 {
 568         char error[256];
 569         snprintf(error, 256, "HTTP/1.0 %d Error\r\nContent-type: text/plain\r\n\r\nSomething went wrong. Sorry.\r\n",
 570                 error_code);
 571         client->header_or_error = error;
 572
 573         // Switch states.
 574         client->state = Client::SENDING_ERROR;
 575
 576         epoll_event ev;
 577         ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
 578         ev.data.u64 = 0;  // Keep Valgrind happy.
 579         ev.data.fd = client->sock;
 580
 581         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 582                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 583                 exit(1);
 584         }
 585 }
 586
 587 void Server::close_client(Client *client)
 588 {
 589         if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
 590                 perror("epoll_ctl(EPOLL_CTL_DEL)");
 591                 exit(1);
 592         }
 593
 594         // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
 595         if (client->stream != NULL) {
 596                 vector<Client *>::iterator new_end =
 597                         remove(client->stream->sleeping_clients.begin(),
 598                                client->stream->sleeping_clients.end(),
 599                                client);
 600                 client->stream->sleeping_clients.erase(
 601                         new_end, client->stream->sleeping_clients.end());
 602         }
 603
 604         // Bye-bye!
 605         int ret;
 606         do {
 607                 ret = close(client->sock);
 608         } while (ret == -1 && errno == EINTR);
 609
 610         if (ret == -1) {
 611                 perror("close");
 612         }
 613
 614         clients.erase(client->sock);
 615 }
 616
 617 Stream *Server::find_stream(const string &stream_id)
 618 {
 619         map<string, Stream *>::iterator it = streams.find(stream_id);
 620         assert(it != streams.end());
 621         return it->second;
 622 }
 623
 624 void Server::process_queued_data()
 625 {
 626         MutexLock lock(&queued_data_mutex);
 627
 628         for (size_t i = 0; i < queued_add_clients.size(); ++i) {
 629                 add_client(queued_add_clients[i]);
 630         }
 631         queued_add_clients.clear();
 632
 633         for (map<string, string>::iterator queued_it = queued_data.begin();
 634              queued_it != queued_data.end();
 635              ++queued_it) {
 636                 add_data(queued_it->first, queued_it->second.data(), queued_it->second.size());
 637         }
 638         queued_data.clear();
 639 }