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