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

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