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