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