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 <time.h>
  13 #include <signal.h>
  14 #include <errno.h>
  15 #include <vector>
  16 #include <string>
  17 #include <map>
  18 #include <algorithm>
  19
  20 #include "markpool.h"
  21 #include "metacube.h"
  22 #include "server.h"
  23 #include "mutexlock.h"
  24 #include "parse.h"
  25 #include "state.pb.h"
  26
  27 using namespace std;
  28
  29 Client::Client(int sock)
  30         : sock(sock),
  31           fwmark(0),
  32           connect_time(time(NULL)),
  33           state(Client::READING_REQUEST),
  34           stream(NULL),
  35           header_or_error_bytes_sent(0),
  36           bytes_sent(0)
  37 {
  38         request.reserve(1024);
  39
  40         // Find the remote address, and convert it to ASCII.
  41         sockaddr_in6 addr;
  42         socklen_t addr_len = sizeof(addr);
  43
  44         if (getpeername(sock, reinterpret_cast<sockaddr *>(&addr), &addr_len) == -1) {
  45                 perror("getpeername");
  46                 remote_addr = "";
  47         } else {
  48                 char buf[INET6_ADDRSTRLEN];
  49                 if (inet_ntop(addr.sin6_family, &addr.sin6_addr, buf, sizeof(buf)) == NULL) {
  50                         perror("inet_ntop");
  51                         remote_addr = "";
  52                 } else {
  53                         remote_addr = buf;
  54                 }
  55         }
  56 }
  57
  58 Client::Client(const ClientProto &serialized, Stream *stream)
  59         : sock(serialized.sock()),
  60           remote_addr(serialized.remote_addr()),
  61           connect_time(serialized.connect_time()),
  62           state(State(serialized.state())),
  63           request(serialized.request()),
  64           stream_id(serialized.stream_id()),
  65           stream(stream),
  66           header_or_error(serialized.header_or_error()),
  67           header_or_error_bytes_sent(serialized.header_or_error_bytes_sent()),
  68           bytes_sent(serialized.bytes_sent())
  69 {
  70         if (stream->mark_pool != NULL) {
  71                 fwmark = stream->mark_pool->get_mark();
  72         } else {
  73                 fwmark = 0;  // No mark.
  74         }
  75         if (setsockopt(sock, SOL_SOCKET, SO_MARK, &fwmark, sizeof(fwmark)) == -1) {
  76                 if (fwmark != 0) {
  77                         perror("setsockopt(SO_MARK)");
  78                 }
  79         }
  80 }
  81
  82 ClientProto Client::serialize() const
  83 {
  84         ClientProto serialized;
  85         serialized.set_sock(sock);
  86         serialized.set_remote_addr(remote_addr);
  87         serialized.set_connect_time(connect_time);
  88         serialized.set_state(state);
  89         serialized.set_request(request);
  90         serialized.set_stream_id(stream_id);
  91         serialized.set_header_or_error(header_or_error);
  92         serialized.set_header_or_error_bytes_sent(serialized.header_or_error_bytes_sent());
  93         serialized.set_bytes_sent(bytes_sent);
  94         return serialized;
  95 }
  96
  97 ClientStats Client::get_stats() const
  98 {
  99         ClientStats stats;
 100         stats.stream_id = stream_id;
 101         stats.remote_addr = remote_addr;
 102         stats.connect_time = connect_time;
 103         stats.bytes_sent = bytes_sent;
 104         return stats;
 105 }
 106
 107 Stream::Stream(const string &stream_id)
 108         : stream_id(stream_id),
 109           data(new char[BACKLOG_SIZE]),
 110           data_size(0),
 111           mark_pool(NULL)
 112 {
 113         memset(data, 0, BACKLOG_SIZE);
 114 }
 115
 116 Stream::~Stream()
 117 {
 118         delete[] data;
 119 }
 120
 121 Stream::Stream(const StreamProto &serialized)
 122         : stream_id(serialized.stream_id()),
 123           header(serialized.header()),
 124           data(new char[BACKLOG_SIZE]),
 125           data_size(serialized.data_size()),
 126           mark_pool(NULL)
 127 {
 128         assert(serialized.data().size() == BACKLOG_SIZE);
 129         memcpy(data, serialized.data().data(), BACKLOG_SIZE);
 130 }
 131
 132 StreamProto Stream::serialize() const
 133 {
 134         StreamProto serialized;
 135         serialized.set_header(header);
 136         serialized.set_data(string(data, data + BACKLOG_SIZE));
 137         serialized.set_data_size(data_size);
 138         serialized.set_stream_id(stream_id);
 139         return serialized;
 140 }
 141
 142 void Stream::put_client_to_sleep(Client *client)
 143 {
 144         sleeping_clients.push_back(client);
 145 }
 146
 147 void Stream::wake_up_all_clients()
 148 {
 149         if (to_process.empty()) {
 150                 swap(sleeping_clients, to_process);
 151         } else {
 152                 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
 153                 sleeping_clients.clear();
 154         }
 155 }
 156
 157 Server::Server()
 158 {
 159         pthread_mutex_init(&mutex, NULL);
 160         pthread_mutex_init(&queued_data_mutex, NULL);
 161
 162         epoll_fd = epoll_create(1024);  // Size argument is ignored.
 163         if (epoll_fd == -1) {
 164                 perror("epoll_fd");
 165                 exit(1);
 166         }
 167 }
 168
 169 Server::~Server()
 170 {
 171         int ret;
 172         do {
 173                 ret = close(epoll_fd);
 174         } while (ret == -1 && errno == EINTR);
 175
 176         if (ret == -1) {
 177                 perror("close(epoll_fd)");
 178         }
 179 }
 180
 181 vector<ClientStats> Server::get_client_stats() const
 182 {
 183         vector<ClientStats> ret;
 184
 185         MutexLock lock(&mutex);
 186         for (map<int, Client>::const_iterator client_it = clients.begin();
 187              client_it != clients.end();
 188              ++client_it) {
 189                 ret.push_back(client_it->second.get_stats());
 190         }
 191         return ret;
 192 }
 193
 194 void Server::do_work()
 195 {
 196         for ( ;; ) {
 197                 int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
 198                 if (nfds == -1 && errno == EINTR) {
 199                         if (should_stop) {
 200                                 return;
 201                         }
 202                         continue;
 203                 }
 204                 if (nfds == -1) {
 205                         perror("epoll_wait");
 206                         exit(1);
 207                 }
 208
 209                 MutexLock lock(&mutex);  // We release the mutex between iterations.
 210
 211                 process_queued_data();
 212
 213                 for (int i = 0; i < nfds; ++i) {
 214                         int fd = events[i].data.fd;
 215                         assert(clients.count(fd) != 0);
 216                         Client *client = &clients[fd];
 217
 218                         if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
 219                                 close_client(client);
 220                                 continue;
 221                         }
 222
 223                         process_client(client);
 224                 }
 225
 226                 for (map<string, Stream *>::iterator stream_it = streams.begin();
 227                      stream_it != streams.end();
 228                      ++stream_it) {
 229                         vector<Client *> to_process;
 230                         swap(stream_it->second->to_process, to_process);
 231                         for (size_t i = 0; i < to_process.size(); ++i) {
 232                                 process_client(to_process[i]);
 233                         }
 234                 }
 235
 236                 if (should_stop) {
 237                         return;
 238                 }
 239         }
 240 }
 241
 242 CubemapStateProto Server::serialize()
 243 {
 244         // We don't serialize anything queued, so empty the queues.
 245         process_queued_data();
 246
 247         CubemapStateProto serialized;
 248         for (map<int, Client>::const_iterator client_it = clients.begin();
 249              client_it != clients.end();
 250              ++client_it) {
 251                 serialized.add_clients()->MergeFrom(client_it->second.serialize());
 252         }
 253         for (map<string, Stream *>::const_iterator stream_it = streams.begin();
 254              stream_it != streams.end();
 255              ++stream_it) {
 256                 serialized.add_streams()->MergeFrom(stream_it->second->serialize());
 257         }
 258         return serialized;
 259 }
 260
 261 void Server::add_client_deferred(int sock)
 262 {
 263         MutexLock lock(&queued_data_mutex);
 264         queued_add_clients.push_back(sock);
 265 }
 266
 267 void Server::add_client(int sock)
 268 {
 269         clients.insert(make_pair(sock, Client(sock)));
 270
 271         // Start listening on data from this socket.
 272         epoll_event ev;
 273         ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
 274         ev.data.u64 = 0;  // Keep Valgrind happy.
 275         ev.data.fd = sock;
 276         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
 277                 perror("epoll_ctl(EPOLL_CTL_ADD)");
 278                 exit(1);
 279         }
 280
 281         process_client(&clients[sock]);
 282 }
 283
 284 void Server::add_client_from_serialized(const ClientProto &client)
 285 {
 286         MutexLock lock(&mutex);
 287         Stream *stream = find_stream(client.stream_id());
 288         clients.insert(make_pair(client.sock(), Client(client, stream)));
 289         Client *client_ptr = &clients[client.sock()];
 290
 291         // Start listening on data from this socket.
 292         epoll_event ev;
 293         if (client.state() == Client::READING_REQUEST) {
 294                 ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
 295         } else {
 296                 // If we don't have more data for this client, we'll be putting it into
 297                 // the sleeping array again soon.
 298                 ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
 299         }
 300         ev.data.u64 = 0;  // Keep Valgrind happy.
 301         ev.data.fd = client.sock();
 302         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, client.sock(), &ev) == -1) {
 303                 perror("epoll_ctl(EPOLL_CTL_ADD)");
 304                 exit(1);
 305         }
 306
 307         if (client_ptr->state == Client::SENDING_DATA &&
 308             client_ptr->bytes_sent == client_ptr->stream->data_size) {
 309                 client_ptr->stream->put_client_to_sleep(client_ptr);
 310         } else {
 311                 process_client(client_ptr);
 312         }
 313 }
 314
 315 void Server::add_stream(const string &stream_id)
 316 {
 317         MutexLock lock(&mutex);
 318         streams.insert(make_pair(stream_id, new Stream(stream_id)));
 319 }
 320
 321 void Server::add_stream_from_serialized(const StreamProto &stream)
 322 {
 323         MutexLock lock(&mutex);
 324         streams.insert(make_pair(stream.stream_id(), new Stream(stream)));
 325 }
 326
 327 void Server::set_header(const string &stream_id, const string &header)
 328 {
 329         MutexLock lock(&mutex);
 330         find_stream(stream_id)->header = header;
 331
 332         // If there are clients we haven't sent anything to yet, we should give
 333         // them the header, so push back into the SENDING_HEADER state.
 334         for (map<int, Client>::iterator client_it = clients.begin();
 335              client_it != clients.end();
 336              ++client_it) {
 337                 Client *client = &client_it->second;
 338                 if (client->state == Client::SENDING_DATA &&
 339                     client->bytes_sent == 0) {
 340                         construct_header(client);
 341                 }
 342         }
 343 }
 344
 345 void Server::set_mark_pool(const std::string &stream_id, MarkPool *mark_pool)
 346 {
 347         MutexLock lock(&mutex);
 348         assert(clients.empty());
 349         find_stream(stream_id)->mark_pool = mark_pool;
 350 }
 351
 352 void Server::add_data_deferred(const string &stream_id, const char *data, size_t bytes)
 353 {
 354         MutexLock lock(&queued_data_mutex);
 355         queued_data[stream_id].append(string(data, data + bytes));
 356 }
 357
 358 void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 359 {
 360         Stream *stream = find_stream(stream_id);
 361         size_t pos = stream->data_size % BACKLOG_SIZE;
 362         stream->data_size += bytes;
 363
 364         if (pos + bytes > BACKLOG_SIZE) {
 365                 size_t to_copy = BACKLOG_SIZE - pos;
 366                 memcpy(stream->data + pos, data, to_copy);
 367                 data += to_copy;
 368                 bytes -= to_copy;
 369                 pos = 0;
 370         }
 371
 372         memcpy(stream->data + pos, data, bytes);
 373         stream->wake_up_all_clients();
 374 }
 375
 376 // See the .h file for postconditions after this function.
 377 void Server::process_client(Client *client)
 378 {
 379         switch (client->state) {
 380         case Client::READING_REQUEST: {
 381 read_request_again:
 382                 // Try to read more of the request.
 383                 char buf[1024];
 384                 int ret;
 385                 do {
 386                         ret = read(client->sock, buf, sizeof(buf));
 387                 } while (ret == -1 && errno == EINTR);
 388
 389                 if (ret == -1 && errno == EAGAIN) {
 390                         // No more data right now. Nothing to do.
 391                         // This is postcondition #2.
 392                         return;
 393                 }
 394                 if (ret == -1) {
 395                         perror("read");
 396                         close_client(client);
 397                         return;
 398                 }
 399                 if (ret == 0) {
 400                         // OK, the socket is closed.
 401                         close_client(client);
 402                         return;
 403                 }
 404
 405                 RequestParseStatus status = wait_for_double_newline(&client->request, buf, ret);
 406
 407                 switch (status) {
 408                 case RP_OUT_OF_SPACE:
 409                         fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
 410                         close_client(client);
 411                         return;
 412                 case RP_NOT_FINISHED_YET:
 413                         // OK, we don't have the entire header yet. Fine; we'll get it later.
 414                         // See if there's more data for us.
 415                         goto read_request_again;
 416                 case RP_EXTRA_DATA:
 417                         fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
 418                         close_client(client);
 419                         return;
 420                 case RP_FINISHED:
 421                         break;
 422                 }
 423
 424                 assert(status == RP_FINISHED);
 425
 426                 int error_code = parse_request(client);
 427                 if (error_code == 200) {
 428                         construct_header(client);
 429                 } else {
 430                         construct_error(client, error_code);
 431                 }
 432
 433                 // We've changed states, so fall through.
 434                 assert(client->state == Client::SENDING_ERROR ||
 435                        client->state == Client::SENDING_HEADER);
 436         }
 437         case Client::SENDING_ERROR:
 438         case Client::SENDING_HEADER: {
 439 sending_header_or_error_again:
 440                 int ret;
 441                 do {
 442                         ret = write(client->sock,
 443                                     client->header_or_error.data() + client->header_or_error_bytes_sent,
 444                                     client->header_or_error.size() - client->header_or_error_bytes_sent);
 445                 } while (ret == -1 && errno == EINTR);
 446
 447                 if (ret == -1 && errno == EAGAIN) {
 448                         // We're out of socket space, so now we're at the “low edge” of epoll's
 449                         // edge triggering. epoll will tell us when there is more room, so for now,
 450                         // just return.
 451                         // This is postcondition #4.
 452                         return;
 453                 }
 454
 455                 if (ret == -1) {
 456                         // Error! Postcondition #1.
 457                         perror("write");
 458                         close_client(client);
 459                         return;
 460                 }
 461
 462                 client->header_or_error_bytes_sent += ret;
 463                 assert(client->header_or_error_bytes_sent <= client->header_or_error.size());
 464
 465                 if (client->header_or_error_bytes_sent < client->header_or_error.size()) {
 466                         // We haven't sent all yet. Fine; go another round.
 467                         goto sending_header_or_error_again;
 468                 }
 469
 470                 // We're done sending the header or error! Clear it to release some memory.
 471                 client->header_or_error.clear();
 472
 473                 if (client->state == Client::SENDING_ERROR) {
 474                         // We're done sending the error, so now close.
 475                         // This is postcondition #1.
 476                         close_client(client);
 477                         return;
 478                 }
 479
 480                 // Start sending from the end. In other words, we won't send any of the backlog,
 481                 // but we'll start sending immediately as we get data.
 482                 // This is postcondition #3.
 483                 client->state = Client::SENDING_DATA;
 484                 client->bytes_sent = client->stream->data_size;
 485                 client->stream->put_client_to_sleep(client);
 486                 return;
 487         }
 488         case Client::SENDING_DATA: {
 489                 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
 490                 // but resync will be the mux's problem.
 491                 Stream *stream = client->stream;
 492                 size_t bytes_to_send = stream->data_size - client->bytes_sent;
 493                 if (bytes_to_send == 0) {
 494                         return;
 495                 }
 496                 if (bytes_to_send > BACKLOG_SIZE) {
 497                         fprintf(stderr, "WARNING: fd %d lost %lld bytes, maybe too slow connection\n",
 498                                 client->sock,
 499                                 (long long int)(bytes_to_send - BACKLOG_SIZE));
 500                         client->bytes_sent = stream->data_size - BACKLOG_SIZE;
 501                         bytes_to_send = BACKLOG_SIZE;
 502                 }
 503
 504                 // See if we need to split across the circular buffer.
 505                 ssize_t ret;
 506                 if ((client->bytes_sent % BACKLOG_SIZE) + bytes_to_send > BACKLOG_SIZE) {
 507                         size_t bytes_first_part = BACKLOG_SIZE - (client->bytes_sent % BACKLOG_SIZE);
 508
 509                         iovec iov[2];
 510                         iov[0].iov_base = const_cast<char *>(stream->data + (client->bytes_sent % BACKLOG_SIZE));
 511                         iov[0].iov_len = bytes_first_part;
 512
 513                         iov[1].iov_base = const_cast<char *>(stream->data);
 514                         iov[1].iov_len = bytes_to_send - bytes_first_part;
 515
 516                         do {
 517                                 ret = writev(client->sock, iov, 2);
 518                         } while (ret == -1 && errno == EINTR);
 519                 } else {
 520                         do {
 521                                 ret = write(client->sock,
 522                                             stream->data + (client->bytes_sent % BACKLOG_SIZE),
 523                                             bytes_to_send);
 524                         } while (ret == -1 && errno == EINTR);
 525                 }
 526                 if (ret == -1 && errno == EAGAIN) {
 527                         // We're out of socket space, so return; epoll will wake us up
 528                         // when there is more room.
 529                         // This is postcondition #4.
 530                         return;
 531                 }
 532                 if (ret == -1) {
 533                         // Error, close; postcondition #1.
 534                         perror("write/writev");
 535                         close_client(client);
 536                         return;
 537                 }
 538                 client->bytes_sent += ret;
 539
 540                 if (client->bytes_sent == stream->data_size) {
 541                         // We don't have any more data for this client, so put it to sleep.
 542                         // This is postcondition #3.
 543                         stream->put_client_to_sleep(client);
 544                 } else {
 545                         // XXX: Do we need to go another round here to explicitly
 546                         // get the EAGAIN?
 547                 }
 548                 break;
 549         }
 550         default:
 551                 assert(false);
 552         }
 553 }
 554
 555 int Server::parse_request(Client *client)
 556 {
 557         vector<string> lines = split_lines(client->request);
 558         if (lines.empty()) {
 559                 return 400;  // Bad request (empty).
 560         }
 561
 562         vector<string> request_tokens = split_tokens(lines[0]);
 563         if (request_tokens.size() < 2) {
 564                 return 400;  // Bad request (empty).
 565         }
 566         if (request_tokens[0] != "GET") {
 567                 return 400;  // Should maybe be 405 instead?
 568         }
 569         if (streams.count(request_tokens[1]) == 0) {
 570                 return 404;  // Not found.
 571         }
 572
 573         client->stream_id = request_tokens[1];
 574         client->stream = find_stream(client->stream_id);
 575         if (client->stream->mark_pool != NULL) {
 576                 client->fwmark = client->stream->mark_pool->get_mark();
 577         } else {
 578                 client->fwmark = 0;  // No mark.
 579         }
 580         if (setsockopt(client->sock, SOL_SOCKET, SO_MARK, &client->fwmark, sizeof(client->fwmark)) == -1) {
 581                 if (client->fwmark != 0) {
 582                         perror("setsockopt(SO_MARK)");
 583                 }
 584         }
 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                 if (client->stream->mark_pool != NULL) {
 648                         int fwmark = client->fwmark;
 649                         client->stream->mark_pool->release_mark(fwmark);
 650                 }
 651         }
 652
 653         // Bye-bye!
 654         int ret;
 655         do {
 656                 ret = close(client->sock);
 657         } while (ret == -1 && errno == EINTR);
 658
 659         if (ret == -1) {
 660                 perror("close");
 661         }
 662
 663         clients.erase(client->sock);
 664 }
 665
 666 Stream *Server::find_stream(const string &stream_id)
 667 {
 668         map<string, Stream *>::iterator it = streams.find(stream_id);
 669         assert(it != streams.end());
 670         return it->second;
 671 }
 672
 673 void Server::process_queued_data()
 674 {
 675         MutexLock lock(&queued_data_mutex);
 676
 677         for (size_t i = 0; i < queued_add_clients.size(); ++i) {
 678                 add_client(queued_add_clients[i]);
 679         }
 680         queued_add_clients.clear();
 681
 682         for (map<string, string>::iterator queued_it = queued_data.begin();
 683              queued_it != queued_data.end();
 684              ++queued_it) {
 685                 add_data(queued_it->first, queued_it->second.data(), queued_it->second.size());
 686         }
 687         queued_data.clear();
 688 }