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 <sys/socket.h>
   7 #include <pthread.h>
   8 #include <sys/types.h>
   9 #include <sys/ioctl.h>
  10 #include <sys/epoll.h>
  11 #include <time.h>
  12 #include <signal.h>
  13 #include <errno.h>
  14 #include <vector>
  15 #include <string>
  16 #include <map>
  17 #include <algorithm>
  18
  19 #include "markpool.h"
  20 #include "metacube.h"
  21 #include "server.h"
  22 #include "mutexlock.h"
  23 #include "parse.h"
  24 #include "state.pb.h"
  25
  26 using namespace std;
  27
  28 Client::Client(int sock)
  29         : sock(sock),
  30           fwmark(0),
  31           connect_time(time(NULL)),
  32           state(Client::READING_REQUEST),
  33           stream(NULL),
  34           header_or_error_bytes_sent(0),
  35           bytes_sent(0)
  36 {
  37         request.reserve(1024);
  38
  39         // Find the remote address, and convert it to ASCII.
  40         sockaddr_in6 addr;
  41         socklen_t addr_len = sizeof(addr);
  42
  43         if (getpeername(sock, reinterpret_cast<sockaddr *>(&addr), &addr_len) == -1) {
  44                 perror("getpeername");
  45                 remote_addr = "";
  46         } else {
  47                 char buf[INET6_ADDRSTRLEN];
  48                 if (inet_ntop(addr.sin6_family, &addr.sin6_addr, buf, sizeof(buf)) == NULL) {
  49                         perror("inet_ntop");
  50                         remote_addr = "";
  51                 } else {
  52                         remote_addr = buf;
  53                 }
  54         }
  55 }
  56
  57 Client::Client(const ClientProto &serialized, Stream *stream)
  58         : sock(serialized.sock()),
  59           remote_addr(serialized.remote_addr()),
  60           connect_time(serialized.connect_time()),
  61           state(State(serialized.state())),
  62           request(serialized.request()),
  63           stream_id(serialized.stream_id()),
  64           stream(stream),
  65           header_or_error(serialized.header_or_error()),
  66           header_or_error_bytes_sent(serialized.header_or_error_bytes_sent()),
  67           bytes_sent(serialized.bytes_sent())
  68 {
  69         if (stream->mark_pool != NULL) {
  70                 fwmark = stream->mark_pool->get_mark();
  71         } else {
  72                 fwmark = 0;  // No mark.
  73         }
  74         if (setsockopt(sock, SOL_SOCKET, SO_MARK, &fwmark, sizeof(fwmark)) == -1) {
  75                 if (fwmark != 0) {
  76                         perror("setsockopt(SO_MARK)");
  77                 }
  78         }
  79 }
  80
  81 ClientProto Client::serialize() const
  82 {
  83         ClientProto serialized;
  84         serialized.set_sock(sock);
  85         serialized.set_remote_addr(remote_addr);
  86         serialized.set_connect_time(connect_time);
  87         serialized.set_state(state);
  88         serialized.set_request(request);
  89         serialized.set_stream_id(stream_id);
  90         serialized.set_header_or_error(header_or_error);
  91         serialized.set_header_or_error_bytes_sent(serialized.header_or_error_bytes_sent());
  92         serialized.set_bytes_sent(bytes_sent);
  93         return serialized;
  94 }
  95
  96 ClientStats Client::get_stats() const
  97 {
  98         ClientStats stats;
  99         stats.stream_id = stream_id;
 100         stats.remote_addr = remote_addr;
 101         stats.connect_time = connect_time;
 102         stats.bytes_sent = bytes_sent;
 103         return stats;
 104 }
 105
 106 Stream::Stream(const string &stream_id)
 107         : stream_id(stream_id),
 108           data(new char[BACKLOG_SIZE]),
 109           data_size(0),
 110           mark_pool(NULL)
 111 {
 112         memset(data, 0, BACKLOG_SIZE);
 113 }
 114
 115 Stream::~Stream()
 116 {
 117         delete[] data;
 118 }
 119
 120 Stream::Stream(const StreamProto &serialized)
 121         : stream_id(serialized.stream_id()),
 122           header(serialized.header()),
 123           data(new char[BACKLOG_SIZE]),
 124           data_size(serialized.data_size()),
 125           mark_pool(NULL)
 126 {
 127         assert(serialized.data().size() == BACKLOG_SIZE);
 128         memcpy(data, serialized.data().data(), BACKLOG_SIZE);
 129 }
 130
 131 StreamProto Stream::serialize() const
 132 {
 133         StreamProto serialized;
 134         serialized.set_header(header);
 135         serialized.set_data(string(data, data + BACKLOG_SIZE));
 136         serialized.set_data_size(data_size);
 137         serialized.set_stream_id(stream_id);
 138         return serialized;
 139 }
 140
 141 void Stream::put_client_to_sleep(Client *client)
 142 {
 143         sleeping_clients.push_back(client);
 144 }
 145
 146 void Stream::wake_up_all_clients()
 147 {
 148         if (to_process.empty()) {
 149                 swap(sleeping_clients, to_process);
 150         } else {
 151                 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
 152                 sleeping_clients.clear();
 153         }
 154 }
 155
 156 Server::Server()
 157 {
 158         pthread_mutex_init(&mutex, NULL);
 159         pthread_mutex_init(&queued_data_mutex, NULL);
 160
 161         epoll_fd = epoll_create(1024);  // Size argument is ignored.
 162         if (epoll_fd == -1) {
 163                 perror("epoll_fd");
 164                 exit(1);
 165         }
 166 }
 167
 168 Server::~Server()
 169 {
 170         int ret;
 171         do {
 172                 ret = close(epoll_fd);
 173         } while (ret == -1 && errno == EINTR);
 174
 175         if (ret == -1) {
 176                 perror("close(epoll_fd)");
 177         }
 178 }
 179
 180 vector<ClientStats> Server::get_client_stats() const
 181 {
 182         vector<ClientStats> ret;
 183
 184         MutexLock lock(&mutex);
 185         for (map<int, Client>::const_iterator client_it = clients.begin();
 186              client_it != clients.end();
 187              ++client_it) {
 188                 ret.push_back(client_it->second.get_stats());
 189         }
 190         return ret;
 191 }
 192
 193 void Server::do_work()
 194 {
 195         for ( ;; ) {
 196                 int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
 197                 if (nfds == -1 && errno == EINTR) {
 198                         if (should_stop) {
 199                                 return;
 200                         }
 201                         continue;
 202                 }
 203                 if (nfds == -1) {
 204                         perror("epoll_wait");
 205                         exit(1);
 206                 }
 207
 208                 MutexLock lock(&mutex);  // We release the mutex between iterations.
 209
 210                 process_queued_data();
 211
 212                 for (int i = 0; i < nfds; ++i) {
 213                         int fd = events[i].data.fd;
 214                         assert(clients.count(fd) != 0);
 215                         Client *client = &clients[fd];
 216
 217                         if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
 218                                 close_client(client);
 219                                 continue;
 220                         }
 221
 222                         process_client(client);
 223                 }
 224
 225                 for (map<string, Stream *>::iterator stream_it = streams.begin();
 226                      stream_it != streams.end();
 227                      ++stream_it) {
 228                         vector<Client *> to_process;
 229                         swap(stream_it->second->to_process, to_process);
 230                         for (size_t i = 0; i < to_process.size(); ++i) {
 231                                 process_client(to_process[i]);
 232                         }
 233                 }
 234
 235                 if (should_stop) {
 236                         return;
 237                 }
 238         }
 239 }
 240
 241 CubemapStateProto Server::serialize()
 242 {
 243         // We don't serialize anything queued, so empty the queues.
 244         process_queued_data();
 245
 246         CubemapStateProto serialized;
 247         for (map<int, Client>::const_iterator client_it = clients.begin();
 248              client_it != clients.end();
 249              ++client_it) {
 250                 serialized.add_clients()->MergeFrom(client_it->second.serialize());
 251         }
 252         for (map<string, Stream *>::const_iterator stream_it = streams.begin();
 253              stream_it != streams.end();
 254              ++stream_it) {
 255                 serialized.add_streams()->MergeFrom(stream_it->second->serialize());
 256         }
 257         return serialized;
 258 }
 259
 260 void Server::add_client_deferred(int sock)
 261 {
 262         MutexLock lock(&queued_data_mutex);
 263         queued_add_clients.push_back(sock);
 264 }
 265
 266 void Server::add_client(int sock)
 267 {
 268         clients.insert(make_pair(sock, Client(sock)));
 269
 270         // Start listening on data from this socket.
 271         epoll_event ev;
 272         ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
 273         ev.data.u64 = 0;  // Keep Valgrind happy.
 274         ev.data.fd = sock;
 275         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
 276                 perror("epoll_ctl(EPOLL_CTL_ADD)");
 277                 exit(1);
 278         }
 279
 280         process_client(&clients[sock]);
 281 }
 282
 283 void Server::add_client_from_serialized(const ClientProto &client)
 284 {
 285         MutexLock lock(&mutex);
 286         Stream *stream = find_stream(client.stream_id());
 287         clients.insert(make_pair(client.sock(), Client(client, stream)));
 288         Client *client_ptr = &clients[client.sock()];
 289
 290         // Start listening on data from this socket.
 291         epoll_event ev;
 292         if (client.state() == Client::READING_REQUEST) {
 293                 ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
 294         } else {
 295                 // If we don't have more data for this client, we'll be putting it into
 296                 // the sleeping array again soon.
 297                 ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
 298         }
 299         ev.data.u64 = 0;  // Keep Valgrind happy.
 300         ev.data.fd = client.sock();
 301         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, client.sock(), &ev) == -1) {
 302                 perror("epoll_ctl(EPOLL_CTL_ADD)");
 303                 exit(1);
 304         }
 305
 306         if (client_ptr->state == Client::SENDING_DATA &&
 307             client_ptr->bytes_sent == client_ptr->stream->data_size) {
 308                 client_ptr->stream->put_client_to_sleep(client_ptr);
 309         } else {
 310                 process_client(client_ptr);
 311         }
 312 }
 313
 314 void Server::add_stream(const string &stream_id)
 315 {
 316         MutexLock lock(&mutex);
 317         streams.insert(make_pair(stream_id, new Stream(stream_id)));
 318 }
 319
 320 void Server::add_stream_from_serialized(const StreamProto &stream)
 321 {
 322         MutexLock lock(&mutex);
 323         streams.insert(make_pair(stream.stream_id(), new Stream(stream)));
 324 }
 325
 326 void Server::set_header(const string &stream_id, const string &header)
 327 {
 328         MutexLock lock(&mutex);
 329         find_stream(stream_id)->header = header;
 330
 331         // If there are clients we haven't sent anything to yet, we should give
 332         // them the header, so push back into the SENDING_HEADER state.
 333         for (map<int, Client>::iterator client_it = clients.begin();
 334              client_it != clients.end();
 335              ++client_it) {
 336                 Client *client = &client_it->second;
 337                 if (client->state == Client::SENDING_DATA &&
 338                     client->bytes_sent == 0) {
 339                         construct_header(client);
 340                 }
 341         }
 342 }
 343
 344 void Server::set_mark_pool(const std::string &stream_id, MarkPool *mark_pool)
 345 {
 346         MutexLock lock(&mutex);
 347         assert(clients.empty());
 348         find_stream(stream_id)->mark_pool = mark_pool;
 349 }
 350
 351 void Server::add_data_deferred(const string &stream_id, const char *data, size_t bytes)
 352 {
 353         MutexLock lock(&queued_data_mutex);
 354         queued_data[stream_id].append(string(data, data + bytes));
 355 }
 356
 357 void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 358 {
 359         Stream *stream = find_stream(stream_id);
 360         size_t pos = stream->data_size % BACKLOG_SIZE;
 361         stream->data_size += bytes;
 362
 363         if (pos + bytes > BACKLOG_SIZE) {
 364                 size_t to_copy = BACKLOG_SIZE - pos;
 365                 memcpy(stream->data + pos, data, to_copy);
 366                 data += to_copy;
 367                 bytes -= to_copy;
 368                 pos = 0;
 369         }
 370
 371         memcpy(stream->data + pos, data, bytes);
 372         stream->wake_up_all_clients();
 373 }
 374
 375 // See the .h file for postconditions after this function.
 376 void Server::process_client(Client *client)
 377 {
 378         switch (client->state) {
 379         case Client::READING_REQUEST: {
 380 read_request_again:
 381                 // Try to read more of the request.
 382                 char buf[1024];
 383                 int ret;
 384                 do {
 385                         ret = read(client->sock, buf, sizeof(buf));
 386                 } while (ret == -1 && errno == EINTR);
 387
 388                 if (ret == -1 && errno == EAGAIN) {
 389                         // No more data right now. Nothing to do.
 390                         // This is postcondition #2.
 391                         return;
 392                 }
 393                 if (ret == -1) {
 394                         perror("read");
 395                         close_client(client);
 396                         return;
 397                 }
 398                 if (ret == 0) {
 399                         // OK, the socket is closed.
 400                         close_client(client);
 401                         return;
 402                 }
 403
 404                 RequestParseStatus status = wait_for_double_newline(&client->request, buf, ret);
 405
 406                 switch (status) {
 407                 case RP_OUT_OF_SPACE:
 408                         fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
 409                         close_client(client);
 410                         return;
 411                 case RP_NOT_FINISHED_YET:
 412                         // OK, we don't have the entire header yet. Fine; we'll get it later.
 413                         // See if there's more data for us.
 414                         goto read_request_again;
 415                 case RP_EXTRA_DATA:
 416                         fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
 417                         close_client(client);
 418                         return;
 419                 case RP_FINISHED:
 420                         break;
 421                 }
 422
 423                 assert(status == RP_FINISHED);
 424
 425                 int error_code = parse_request(client);
 426                 if (error_code == 200) {
 427                         construct_header(client);
 428                 } else {
 429                         construct_error(client, error_code);
 430                 }
 431
 432                 // We've changed states, so fall through.
 433                 assert(client->state == Client::SENDING_ERROR ||
 434                        client->state == Client::SENDING_HEADER);
 435         }
 436         case Client::SENDING_ERROR:
 437         case Client::SENDING_HEADER: {
 438 sending_header_or_error_again:
 439                 int ret;
 440                 do {
 441                         ret = write(client->sock,
 442                                     client->header_or_error.data() + client->header_or_error_bytes_sent,
 443                                     client->header_or_error.size() - client->header_or_error_bytes_sent);
 444                 } while (ret == -1 && errno == EINTR);
 445
 446                 if (ret == -1 && errno == EAGAIN) {
 447                         // We're out of socket space, so now we're at the “low edge” of epoll's
 448                         // edge triggering. epoll will tell us when there is more room, so for now,
 449                         // just return.
 450                         // This is postcondition #4.
 451                         return;
 452                 }
 453
 454                 if (ret == -1) {
 455                         // Error! Postcondition #1.
 456                         perror("write");
 457                         close_client(client);
 458                         return;
 459                 }
 460
 461                 client->header_or_error_bytes_sent += ret;
 462                 assert(client->header_or_error_bytes_sent <= client->header_or_error.size());
 463
 464                 if (client->header_or_error_bytes_sent < client->header_or_error.size()) {
 465                         // We haven't sent all yet. Fine; go another round.
 466                         goto sending_header_or_error_again;
 467                 }
 468
 469                 // We're done sending the header or error! Clear it to release some memory.
 470                 client->header_or_error.clear();
 471
 472                 if (client->state == Client::SENDING_ERROR) {
 473                         // We're done sending the error, so now close.
 474                         // This is postcondition #1.
 475                         close_client(client);
 476                         return;
 477                 }
 478
 479                 // Start sending from the end. In other words, we won't send any of the backlog,
 480                 // but we'll start sending immediately as we get data.
 481                 // This is postcondition #3.
 482                 client->state = Client::SENDING_DATA;
 483                 client->bytes_sent = client->stream->data_size;
 484                 client->stream->put_client_to_sleep(client);
 485                 return;
 486         }
 487         case Client::SENDING_DATA: {
 488                 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
 489                 // but resync will be the mux's problem.
 490                 Stream *stream = client->stream;
 491                 size_t bytes_to_send = stream->data_size - client->bytes_sent;
 492                 if (bytes_to_send == 0) {
 493                         return;
 494                 }
 495                 if (bytes_to_send > BACKLOG_SIZE) {
 496                         fprintf(stderr, "WARNING: fd %d lost %lld bytes, maybe too slow connection\n",
 497                                 client->sock,
 498                                 (long long int)(bytes_to_send - BACKLOG_SIZE));
 499                         client->bytes_sent = stream->data_size - BACKLOG_SIZE;
 500                         bytes_to_send = BACKLOG_SIZE;
 501                 }
 502
 503                 // See if we need to split across the circular buffer.
 504                 ssize_t ret;
 505                 if ((client->bytes_sent % BACKLOG_SIZE) + bytes_to_send > BACKLOG_SIZE) {
 506                         size_t bytes_first_part = BACKLOG_SIZE - (client->bytes_sent % BACKLOG_SIZE);
 507
 508                         iovec iov[2];
 509                         iov[0].iov_base = const_cast<char *>(stream->data + (client->bytes_sent % BACKLOG_SIZE));
 510                         iov[0].iov_len = bytes_first_part;
 511
 512                         iov[1].iov_base = const_cast<char *>(stream->data);
 513                         iov[1].iov_len = bytes_to_send - bytes_first_part;
 514
 515                         do {
 516                                 ret = writev(client->sock, iov, 2);
 517                         } while (ret == -1 && errno == EINTR);
 518                 } else {
 519                         do {
 520                                 ret = write(client->sock,
 521                                             stream->data + (client->bytes_sent % BACKLOG_SIZE),
 522                                             bytes_to_send);
 523                         } while (ret == -1 && errno == EINTR);
 524                 }
 525                 if (ret == -1 && errno == EAGAIN) {
 526                         // We're out of socket space, so return; epoll will wake us up
 527                         // when there is more room.
 528                         // This is postcondition #4.
 529                         return;
 530                 }
 531                 if (ret == -1) {
 532                         // Error, close; postcondition #1.
 533                         perror("write/writev");
 534                         close_client(client);
 535                         return;
 536                 }
 537                 client->bytes_sent += ret;
 538
 539                 if (client->bytes_sent == stream->data_size) {
 540                         // We don't have any more data for this client, so put it to sleep.
 541                         // This is postcondition #3.
 542                         stream->put_client_to_sleep(client);
 543                 } else {
 544                         // XXX: Do we need to go another round here to explicitly
 545                         // get the EAGAIN?
 546                 }
 547                 break;
 548         }
 549         default:
 550                 assert(false);
 551         }
 552 }
 553
 554 int Server::parse_request(Client *client)
 555 {
 556         vector<string> lines = split_lines(client->request);
 557         if (lines.empty()) {
 558                 return 400;  // Bad request (empty).
 559         }
 560
 561         vector<string> request_tokens = split_tokens(lines[0]);
 562         if (request_tokens.size() < 2) {
 563                 return 400;  // Bad request (empty).
 564         }
 565         if (request_tokens[0] != "GET") {
 566                 return 400;  // Should maybe be 405 instead?
 567         }
 568         if (streams.count(request_tokens[1]) == 0) {
 569                 return 404;  // Not found.
 570         }
 571
 572         client->stream_id = request_tokens[1];
 573         client->stream = find_stream(client->stream_id);
 574         if (client->stream->mark_pool != NULL) {
 575                 client->fwmark = client->stream->mark_pool->get_mark();
 576         } else {
 577                 client->fwmark = 0;  // No mark.
 578         }
 579         if (setsockopt(client->sock, SOL_SOCKET, SO_MARK, &client->fwmark, sizeof(client->fwmark)) == -1) {
 580                 if (client->fwmark != 0) {
 581                         perror("setsockopt(SO_MARK)");
 582                 }
 583         }
 584         client->request.clear();
 585
 586         return 200;  // OK!
 587 }
 588
 589 void Server::construct_header(Client *client)
 590 {
 591         client->header_or_error = find_stream(client->stream_id)->header;
 592
 593         // Switch states.
 594         client->state = Client::SENDING_HEADER;
 595
 596         epoll_event ev;
 597         ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
 598         ev.data.u64 = 0;  // Keep Valgrind happy.
 599         ev.data.fd = client->sock;
 600
 601         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 602                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 603                 exit(1);
 604         }
 605 }
 606
 607 void Server::construct_error(Client *client, int error_code)
 608 {
 609         char error[256];
 610         snprintf(error, 256, "HTTP/1.0 %d Error\r\nContent-type: text/plain\r\n\r\nSomething went wrong. Sorry.\r\n",
 611                 error_code);
 612         client->header_or_error = error;
 613
 614         // Switch states.
 615         client->state = Client::SENDING_ERROR;
 616
 617         epoll_event ev;
 618         ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
 619         ev.data.u64 = 0;  // Keep Valgrind happy.
 620         ev.data.fd = client->sock;
 621
 622         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 623                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 624                 exit(1);
 625         }
 626 }
 627
 628 template<class T>
 629 void delete_from(vector<T> *v, T elem)
 630 {
 631         typename vector<T>::iterator new_end = remove(v->begin(), v->end(), elem);
 632         v->erase(new_end, v->end());
 633 }
 634
 635 void Server::close_client(Client *client)
 636 {
 637         if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
 638                 perror("epoll_ctl(EPOLL_CTL_DEL)");
 639                 exit(1);
 640         }
 641
 642         // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
 643         if (client->stream != NULL) {
 644                 delete_from(&client->stream->sleeping_clients, client);
 645                 delete_from(&client->stream->to_process, client);
 646                 if (client->stream->mark_pool != NULL) {
 647                         int fwmark = client->fwmark;
 648                         client->stream->mark_pool->release_mark(fwmark);
 649                 }
 650         }
 651
 652         // Bye-bye!
 653         int ret;
 654         do {
 655                 ret = close(client->sock);
 656         } while (ret == -1 && errno == EINTR);
 657
 658         if (ret == -1) {
 659                 perror("close");
 660         }
 661
 662         clients.erase(client->sock);
 663 }
 664
 665 Stream *Server::find_stream(const string &stream_id)
 666 {
 667         map<string, Stream *>::iterator it = streams.find(stream_id);
 668         assert(it != streams.end());
 669         return it->second;
 670 }
 671
 672 void Server::process_queued_data()
 673 {
 674         MutexLock lock(&queued_data_mutex);
 675
 676         for (size_t i = 0; i < queued_add_clients.size(); ++i) {
 677                 add_client(queued_add_clients[i]);
 678         }
 679         queued_add_clients.clear();
 680
 681         for (map<string, string>::iterator queued_it = queued_data.begin();
 682              queued_it != queued_data.end();
 683              ++queued_it) {
 684                 add_data(queued_it->first, queued_it->second.data(), queued_it->second.size());
 685         }
 686         queued_data.clear();
 687 }