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