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

   1 #include <assert.h>
   2 #include <errno.h>
   3 #include <math.h>
   4 #include <netdb.h>
   5 #include <netinet/in.h>
   6 #include <poll.h>
   7 #include <stdint.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <sys/ioctl.h>
  11 #include <sys/socket.h>
  12 #include <sys/time.h>
  13 #include <time.h>
  14 #include <unistd.h>
  15 #include <math.h>
  16 #include <map>
  17 #include <string>
  18 #include <utility>
  19 #include <vector>
  20
  21 #include "httpinput.h"
  22 #include "log.h"
  23 #include "metacube2.h"
  24 #include "parse.h"
  25 #include "serverpool.h"
  26 #include "state.pb.h"
  27 #include "stream.h"
  28 #include "timespec.h"
  29 #include "util.h"
  30 #include "version.h"
  31
  32 using namespace std;
  33
  34 namespace {
  35
  36 string host_header(const string &host, const string &port)
  37 {
  38         if (port == "http" || atoi(port.c_str()) == 80) {
  39                 return host;
  40         } else {
  41                 return host + ":" + port;
  42         }
  43 }
  44
  45 }  // namespace
  46
  47 extern ServerPool *servers;
  48
  49 HTTPInput::HTTPInput(const string &url, Input::Encoding encoding)
  50         : state(NOT_CONNECTED),
  51           url(url),
  52           encoding(encoding)
  53 {
  54         stats.url = url;
  55         stats.bytes_received = 0;
  56         stats.data_bytes_received = 0;
  57         stats.metadata_bytes_received = 0;
  58         stats.connect_time = -1;
  59         stats.latency_sec = HUGE_VAL;
  60 }
  61
  62 HTTPInput::HTTPInput(const InputProto &serialized)
  63         : state(State(serialized.state())),
  64           url(serialized.url()),
  65           encoding(serialized.is_metacube_encoded() ?
  66                    Input::INPUT_ENCODING_METACUBE :
  67                    Input::INPUT_ENCODING_RAW),
  68           request(serialized.request()),
  69           request_bytes_sent(serialized.request_bytes_sent()),
  70           response(serialized.response()),
  71           http_header(serialized.http_header()),
  72           stream_header(serialized.stream_header()),
  73           has_metacube_header(serialized.has_metacube_header()),
  74           sock(serialized.sock())
  75 {
  76         pending_data.resize(serialized.pending_data().size());
  77         memcpy(&pending_data[0], serialized.pending_data().data(), serialized.pending_data().size());
  78
  79         string protocol, user;
  80         parse_url(url, &protocol, &user, &host, &port, &path);  // Don't care if it fails.
  81
  82         stats.url = url;
  83         stats.bytes_received = serialized.bytes_received();
  84         stats.data_bytes_received = serialized.data_bytes_received();
  85         stats.metadata_bytes_received = serialized.metadata_bytes_received();
  86         if (serialized.has_connect_time()) {
  87                 stats.connect_time = serialized.connect_time();
  88         } else {
  89                 stats.connect_time = time(nullptr);
  90         }
  91         if (serialized.has_latency_sec()) {
  92                 stats.latency_sec = serialized.latency_sec();
  93         } else {
  94                 stats.latency_sec = HUGE_VAL;
  95         }
  96
  97         last_verbose_connection.tv_sec = -3600;
  98         last_verbose_connection.tv_nsec = 0;
  99 }
 100
 101 void HTTPInput::close_socket()
 102 {
 103         if (sock != -1) {
 104                 safe_close(sock);
 105                 sock = -1;
 106         }
 107
 108         lock_guard<mutex> lock(stats_mutex);
 109         stats.connect_time = -1;
 110 }
 111
 112 InputProto HTTPInput::serialize() const
 113 {
 114         InputProto serialized;
 115         serialized.set_state(state);
 116         serialized.set_url(url);
 117         serialized.set_request(request);
 118         serialized.set_request_bytes_sent(request_bytes_sent);
 119         serialized.set_response(response);
 120         serialized.set_http_header(http_header);
 121         serialized.set_stream_header(stream_header);
 122         serialized.set_pending_data(string(pending_data.begin(), pending_data.end()));
 123         serialized.set_has_metacube_header(has_metacube_header);
 124         serialized.set_sock(sock);
 125         serialized.set_bytes_received(stats.bytes_received);
 126         serialized.set_data_bytes_received(stats.data_bytes_received);
 127         if (isfinite(stats.latency_sec)) {
 128                 serialized.set_latency_sec(stats.latency_sec);
 129         }
 130         serialized.set_connect_time(stats.connect_time);
 131         if (encoding == Input::INPUT_ENCODING_METACUBE) {
 132                 serialized.set_is_metacube_encoded(true);
 133         } else {
 134                 assert(encoding == Input::INPUT_ENCODING_RAW);
 135                 serialized.set_is_metacube_encoded(false);
 136         }
 137         return serialized;
 138 }
 139
 140 int HTTPInput::lookup_and_connect(const string &host, const string &port)
 141 {
 142         addrinfo *ai;
 143         int err = getaddrinfo(host.c_str(), port.c_str(), nullptr, &ai);
 144         if (err != 0) {
 145                 if (!suppress_logging) {
 146                         log(WARNING, "[%s] Lookup of '%s' failed (%s).",
 147                                 url.c_str(), host.c_str(), gai_strerror(err));
 148                 }
 149                 return -1;
 150         }
 151
 152         addrinfo *base_ai = ai;
 153
 154         // Connect to everything in turn until we have a socket.
 155         for ( ; ai && !should_stop(); ai = ai->ai_next) {
 156                 int sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 157                 if (sock == -1) {
 158                         // Could be e.g. EPROTONOSUPPORT. The show must go on.
 159                         continue;
 160                 }
 161
 162                 // Now do a non-blocking connect. This is important because we want to be able to be
 163                 // woken up, even though it's rather cumbersome.
 164
 165                 // Set the socket as nonblocking.
 166                 int one = 1;
 167                 if (ioctl(sock, FIONBIO, &one) == -1) {
 168                         log_perror("ioctl(FIONBIO)");
 169                         safe_close(sock);
 170                         freeaddrinfo(base_ai);
 171                         return -1;
 172                 }
 173
 174                 // Do a non-blocking connect.
 175                 do {
 176                         err = connect(sock, ai->ai_addr, ai->ai_addrlen);
 177                 } while (err == -1 && errno == EINTR);
 178
 179                 if (err == -1 && errno != EINPROGRESS) {
 180                         log_perror("connect");
 181                         safe_close(sock);
 182                         continue;
 183                 }
 184
 185                 // Wait for the connect to complete, or an error to happen.
 186                 for ( ;; ) {
 187                         bool complete = wait_for_activity(sock, POLLIN | POLLOUT, nullptr);
 188                         if (should_stop()) {
 189                                 safe_close(sock);
 190                                 return -1;
 191                         }
 192                         if (complete) {
 193                                 break;
 194                         }
 195                 }
 196
 197                 // Check whether it ended in an error or not.
 198                 socklen_t err_size = sizeof(err);
 199                 if (getsockopt(sock, SOL_SOCKET, SO_ERROR, &err, &err_size) == -1) {
 200                         log_perror("getsockopt");
 201                         safe_close(sock);
 202                         continue;
 203                 }
 204
 205                 errno = err;
 206
 207                 if (err == 0) {
 208                         // Successful connect.
 209                         freeaddrinfo(base_ai);
 210                         return sock;
 211                 }
 212
 213                 safe_close(sock);
 214         }
 215
 216         // Give the last one as error.
 217         if (!suppress_logging) {
 218                 log(WARNING, "[%s] Connect to '%s' failed (%s)",
 219                         url.c_str(), host.c_str(), strerror(errno));
 220         }
 221         freeaddrinfo(base_ai);
 222         return -1;
 223 }
 224
 225 bool HTTPInput::parse_response(const string &request)
 226 {
 227         vector<string> lines = split_lines(response);
 228         if (lines.empty()) {
 229                 if (!suppress_logging) {
 230                         log(WARNING, "[%s] Empty HTTP response from input.", url.c_str());
 231                 }
 232                 return false;
 233         }
 234
 235         vector<string> first_line_tokens = split_tokens(lines[0]);
 236         if (first_line_tokens.size() < 2) {
 237                 if (!suppress_logging) {
 238                         log(WARNING, "[%s] Malformed response line '%s' from input.",
 239                                 url.c_str(), lines[0].c_str());
 240                 }
 241                 return false;
 242         }
 243
 244         int response = atoi(first_line_tokens[1].c_str());
 245         if (response != 200) {
 246                 if (!suppress_logging) {
 247                         log(WARNING, "[%s] Non-200 response '%s' from input.",
 248                                 url.c_str(), lines[0].c_str());
 249                 }
 250                 return false;
 251         }
 252
 253         HTTPHeaderMultimap parameters = extract_headers(lines, url);
 254
 255         // Remove “Content-encoding: metacube”.
 256         const auto encoding_it = parameters.find("Content-Encoding");
 257         if (encoding_it != parameters.end() && encoding_it->second == "metacube") {
 258                 parameters.erase(encoding_it);
 259         }
 260
 261         // Change “Server: foo” to “Server: metacube/0.1 (reflecting: foo)”
 262         // XXX: Use a Via: instead?
 263         if (parameters.count("Server") == 0) {
 264                 parameters.insert(make_pair("Server", SERVER_IDENTIFICATION));
 265         } else {
 266                 for (auto &key_and_value : parameters) {
 267                         if (key_and_value.first != "Server") {
 268                                 continue;
 269                         }
 270                         key_and_value.second = SERVER_IDENTIFICATION " (reflecting: " + key_and_value.second + ")";
 271                 }
 272         }
 273
 274         // Erase “Connection: close”; we'll set it on the sending side if needed.
 275         parameters.erase("Connection");
 276
 277         // Construct the new HTTP header.
 278         http_header = "HTTP/1.0 200 OK\r\n";
 279         for (const auto &key_and_value : parameters) {
 280                 http_header.append(key_and_value.first + ": " + key_and_value.second + "\r\n");
 281         }
 282
 283         for (int stream_index : stream_indices) {
 284                 servers->set_header(stream_index, http_header, stream_header);
 285         }
 286
 287         return true;
 288 }
 289
 290 void HTTPInput::do_work()
 291 {
 292         timespec last_activity;
 293
 294         // TODO: Make the timeout persist across restarts.
 295         if (state == SENDING_REQUEST || state == RECEIVING_HEADER || state == RECEIVING_DATA) {
 296                 int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &last_activity);
 297                 assert(err != -1);
 298         }
 299
 300         while (!should_stop()) {
 301                 if (state == SENDING_REQUEST || state == RECEIVING_HEADER || state == RECEIVING_DATA) {
 302                         // Give the socket 30 seconds since last activity before we time out.
 303                         static const int timeout_secs = 30;
 304
 305                         timespec now;
 306                         int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &now);
 307                         assert(err != -1);
 308
 309                         timespec elapsed = clock_diff(last_activity, now);
 310                         if (elapsed.tv_sec >= timeout_secs) {
 311                                 // Timeout!
 312                                 if (!suppress_logging) {
 313                                         log(ERROR, "[%s] Timeout after %d seconds, closing.", url.c_str(), elapsed.tv_sec);
 314                                 }
 315                                 state = CLOSING_SOCKET;
 316                                 continue;
 317                         }
 318
 319                         // Basically calculate (30 - (now - last_activity)) = (30 + (last_activity - now)).
 320                         // Add a second of slack to account for differences between clocks.
 321                         timespec timeout = clock_diff(now, last_activity);
 322                         timeout.tv_sec += timeout_secs + 1;
 323                         assert(timeout.tv_sec > 0 || (timeout.tv_sec >= 0 && timeout.tv_nsec > 0));
 324
 325                         bool activity = wait_for_activity(sock, (state == SENDING_REQUEST) ? POLLOUT : POLLIN, &timeout);
 326                         if (activity) {
 327                                 err = clock_gettime(CLOCK_MONOTONIC_COARSE, &last_activity);
 328                                 assert(err != -1);
 329                         } else {
 330                                 // OK. Most likely, should_stop was set, or we have timed out.
 331                                 continue;
 332                         }
 333                 }
 334
 335                 switch (state) {
 336                 case NOT_CONNECTED:
 337                         request.clear();
 338                         request_bytes_sent = 0;
 339                         response.clear();
 340                         pending_data.clear();
 341                         has_metacube_header = false;
 342                         for (int stream_index : stream_indices) {
 343                                 servers->set_header(stream_index, "", "");
 344                         }
 345
 346                         {
 347                                 string protocol, user;  // Thrown away.
 348                                 if (!parse_url(url, &protocol, &user, &host, &port, &path)) {
 349                                         if (!suppress_logging) {
 350                                                 log(WARNING, "[%s] Failed to parse URL '%s'", url.c_str(), url.c_str());
 351                                         }
 352                                         break;
 353                                 }
 354
 355                                 // Remove the brackets around IPv6 address literals.
 356                                 // TODO: See if we can join this with the code in parse_ip_address(),
 357                                 // or maybe even more it into parse_url().
 358                                 if (!host.empty() && host[0] == '[' && host[host.size() - 1] == ']') {
 359                                         host = host.substr(1, host.size() - 2);
 360                                 }
 361                         }
 362
 363                         if (suppress_logging) {
 364                                 // See if there's more than one minute since last time we made a connection
 365                                 // with logging enabled. If so, turn it on again.
 366                                 timespec now;
 367                                 int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &now);
 368                                 assert(err != -1);
 369
 370                                 double elapsed = now.tv_sec - last_verbose_connection.tv_sec +
 371                                         1e-9 * (now.tv_nsec - last_verbose_connection.tv_nsec);
 372                                 if (elapsed > 60.0) {
 373                                         suppress_logging = false;
 374                                 }
 375                         }
 376                         if (!suppress_logging) {
 377                                 int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &last_verbose_connection);
 378                                 assert(err != -1);
 379                         }
 380                         ++num_connection_attempts;
 381                         sock = lookup_and_connect(host, port);
 382                         if (sock != -1) {
 383                                 // Yay, successful connect. Try to set it as nonblocking.
 384                                 int one = 1;
 385                                 if (ioctl(sock, FIONBIO, &one) == -1) {
 386                                         log_perror("ioctl(FIONBIO)");
 387                                         state = CLOSING_SOCKET;
 388                                 } else {
 389                                         state = SENDING_REQUEST;
 390                                         request = "GET " + path + " HTTP/1.0\r\nHost: " + host_header(host, port) + "\r\nUser-Agent: cubemap\r\n\r\n";
 391                                         request_bytes_sent = 0;
 392                                 }
 393
 394                                 lock_guard<mutex> lock(stats_mutex);
 395                                 stats.connect_time = time(nullptr);
 396                                 clock_gettime(CLOCK_MONOTONIC_COARSE, &last_activity);
 397                         }
 398                         break;
 399                 case SENDING_REQUEST: {
 400                         size_t to_send = request.size() - request_bytes_sent;
 401                         int ret;
 402
 403                         do {
 404                                 ret = write(sock, request.data() + request_bytes_sent, to_send);
 405                         } while (ret == -1 && errno == EINTR);
 406
 407                         if (ret == -1) {
 408                                 log_perror("write");
 409                                 state = CLOSING_SOCKET;
 410                                 continue;
 411                         }
 412
 413                         assert(ret >= 0);
 414                         request_bytes_sent += ret;
 415
 416                         if (request_bytes_sent == request.size()) {
 417                                 state = RECEIVING_HEADER;
 418                         }
 419                         break;
 420                 }
 421                 case RECEIVING_HEADER: {
 422                         char buf[4096];
 423                         int ret;
 424
 425                         do {
 426                                 ret = read(sock, buf, sizeof(buf));
 427                         } while (ret == -1 && errno == EINTR);
 428
 429                         if (ret == -1) {
 430                                 log_perror("read");
 431                                 state = CLOSING_SOCKET;
 432                                 continue;
 433                         }
 434
 435                         if (ret == 0) {
 436                                 // This really shouldn't happen...
 437                                 if (!suppress_logging) {
 438                                         log(ERROR, "[%s] Socket unexpectedly closed while reading header",
 439                                                    url.c_str());
 440                                 }
 441                                 state = CLOSING_SOCKET;
 442                                 continue;
 443                         }
 444
 445                         RequestParseStatus status = wait_for_double_newline(&response, buf, ret);
 446
 447                         if (status == RP_OUT_OF_SPACE) {
 448                                 if (!suppress_logging) {
 449                                         log(WARNING, "[%s] Server sent overlong HTTP response!", url.c_str());
 450                                 }
 451                                 state = CLOSING_SOCKET;
 452                                 continue;
 453                         } else if (status == RP_NOT_FINISHED_YET) {
 454                                 continue;
 455                         }
 456
 457                         // OK, so we're fine, but there might be some of the actual data after the response.
 458                         // We'll need to deal with that separately.
 459                         string extra_data;
 460                         if (status == RP_EXTRA_DATA) {
 461                                 char *ptr = static_cast<char *>(
 462                                         memmem(response.data(), response.size(), "\r\n\r\n", 4));
 463                                 assert(ptr != nullptr);
 464                                 extra_data = string(ptr + 4, &response[0] + response.size());
 465                                 response.resize(ptr - response.data());
 466                         }
 467
 468                         if (!parse_response(response)) {
 469                                 state = CLOSING_SOCKET;
 470                                 continue;
 471                         }
 472
 473                         if (!extra_data.empty()) {
 474                                 process_data(&extra_data[0], extra_data.size());
 475                         }
 476
 477                         if (!suppress_logging) {
 478                                 if (encoding == Input::INPUT_ENCODING_RAW) {
 479                                         log(INFO, "[%s] Connected to '%s', receiving raw data.",
 480                                                    url.c_str(), url.c_str());
 481                                 } else {
 482                                         assert(encoding == Input::INPUT_ENCODING_METACUBE);
 483                                         log(INFO, "[%s] Connected to '%s', receiving data.",
 484                                                    url.c_str(), url.c_str());
 485                                 }
 486                         }
 487                         state = RECEIVING_DATA;
 488                         break;
 489                 }
 490                 case RECEIVING_DATA: {
 491                         char buf[4096];
 492                         int ret;
 493
 494                         do {
 495                                 ret = read(sock, buf, sizeof(buf));
 496                         } while (ret == -1 && errno == EINTR);
 497
 498                         if (ret == -1) {
 499                                 log_perror("read");
 500                                 state = CLOSING_SOCKET;
 501                                 continue;
 502                         }
 503
 504                         if (ret == 0) {
 505                                 // This really shouldn't happen...
 506                                 if (!suppress_logging) {
 507                                         log(ERROR, "[%s] Socket unexpectedly closed while reading data",
 508                                                    url.c_str());
 509                                 }
 510                                 state = CLOSING_SOCKET;
 511                                 continue;
 512                         }
 513
 514                         num_connection_attempts = 0;  // Reset, since we have a successful read.
 515                         if (suppress_logging) {
 516                                 // This was suppressed earlier, so print it out now.
 517                                 if (encoding == Input::INPUT_ENCODING_RAW) {
 518                                         log(INFO, "[%s] Connected to '%s', receiving raw data.",
 519                                                    url.c_str(), url.c_str());
 520                                 } else {
 521                                         assert(encoding == Input::INPUT_ENCODING_METACUBE);
 522                                         log(INFO, "[%s] Connected to '%s', receiving data.",
 523                                                    url.c_str(), url.c_str());
 524                                 }
 525                                 suppress_logging = false;
 526                         }
 527
 528                         process_data(buf, ret);
 529                         break;
 530                 }
 531                 case CLOSING_SOCKET: {
 532                         close_socket();
 533                         state = NOT_CONNECTED;
 534                         break;
 535                 }
 536                 default:
 537                         assert(false);
 538                 }
 539
 540                 // If we are still in NOT_CONNECTED, either something went wrong,
 541                 // or the connection just got closed.
 542                 // The earlier steps have already given the error message, if any.
 543                 if (state == NOT_CONNECTED && !should_stop()) {
 544                         if (!suppress_logging) {
 545                                 log(INFO, "[%s] Waiting 0.2 seconds and restarting...", url.c_str());
 546                         }
 547
 548                         if (num_connection_attempts >= 3 && !suppress_logging) {
 549                                 log(INFO, "[%s] %d failed connection attempts, suppressing logging for one minute.",
 550                                         url.c_str(), num_connection_attempts);
 551                                 suppress_logging = true;
 552                         }
 553                         timespec timeout_ts;
 554                         timeout_ts.tv_sec = 0;
 555                         timeout_ts.tv_nsec = 200000000;
 556                         wait_for_wakeup(&timeout_ts);
 557                 }
 558         }
 559 }
 560
 561 void HTTPInput::process_data(char *ptr, size_t bytes)
 562 {
 563         {
 564                 lock_guard<mutex> lock(stats_mutex);
 565                 stats.bytes_received += bytes;
 566         }
 567
 568         if (encoding == Input::INPUT_ENCODING_RAW) {
 569                 for (int stream_index : stream_indices) {
 570                         servers->add_data(stream_index, ptr, bytes, /*metacube_flags=*/0, /*pts=*/RationalPTS());
 571                 }
 572                 return;
 573         }
 574
 575         assert(encoding == Input::INPUT_ENCODING_METACUBE);
 576         pending_data.insert(pending_data.end(), ptr, ptr + bytes);
 577
 578         for ( ;; ) {
 579                 // If we don't have enough data (yet) for even the Metacube header, just return.
 580                 if (pending_data.size() < sizeof(metacube2_block_header)) {
 581                         return;
 582                 }
 583
 584                 // Make sure we have the Metacube sync header at the start.
 585                 // We may need to skip over junk data (it _should_ not happen, though).
 586                 if (!has_metacube_header) {
 587                         char *ptr = static_cast<char *>(
 588                                 memmem(pending_data.data(), pending_data.size(),
 589                                        METACUBE2_SYNC, strlen(METACUBE2_SYNC)));
 590                         if (ptr == nullptr) {
 591                                 // OK, so we didn't find the sync marker. We know then that
 592                                 // we do not have the _full_ marker in the buffer, but we
 593                                 // could have N-1 bytes. Drop everything before that,
 594                                 // and then give up.
 595                                 drop_pending_data(pending_data.size() - (strlen(METACUBE2_SYNC) - 1));
 596                                 return;
 597                         } else {
 598                                 // Yay, we found the header. Drop everything (if anything) before it.
 599                                 drop_pending_data(ptr - pending_data.data());
 600                                 has_metacube_header = true;
 601
 602                                 // Re-check that we have the entire header; we could have dropped data.
 603                                 if (pending_data.size() < sizeof(metacube2_block_header)) {
 604                                         return;
 605                                 }
 606                         }
 607                 }
 608
 609                 // Now it's safe to read the header.
 610                 metacube2_block_header hdr;
 611                 memcpy(&hdr, pending_data.data(), sizeof(hdr));
 612                 assert(memcmp(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync)) == 0);
 613                 uint32_t size = ntohl(hdr.size);
 614                 uint16_t flags = ntohs(hdr.flags);
 615                 uint16_t expected_csum = metacube2_compute_crc(&hdr);
 616
 617                 if (expected_csum != ntohs(hdr.csum)) {
 618                         log(WARNING, "[%s] Metacube checksum failed (expected 0x%x, got 0x%x), "
 619                                 "not reading block claiming to be %d bytes (flags=%x).",
 620                                 url.c_str(), expected_csum, ntohs(hdr.csum),
 621                                 size, flags);
 622
 623                         // Drop only the first byte, and let the rest of the code handle resync.
 624                         pending_data.erase(pending_data.begin(), pending_data.begin() + 1);
 625                         has_metacube_header = false;
 626                         continue;
 627                 }
 628                 if (size > 10485760) {
 629                         log(WARNING, "[%s] Metacube block of %d bytes (flags=%x); corrupted header??",
 630                                 url.c_str(), size, flags);
 631                 }
 632
 633                 // See if we have the entire block. If not, wait for more data.
 634                 if (pending_data.size() < sizeof(metacube2_block_header) + size) {
 635                         return;
 636                 }
 637
 638                 // See if this is a metadata block. If so, we don't want to send it on,
 639                 // but rather process it ourselves.
 640                 // TODO: Keep metadata when sending on to other Metacube users.
 641                 if (flags & METACUBE_FLAGS_METADATA) {
 642                         {
 643                                 lock_guard<mutex> lock(stats_mutex);
 644                                 stats.metadata_bytes_received += size;
 645                         }
 646                         process_metacube_metadata_block(hdr, pending_data.data() + sizeof(hdr), size);
 647                 } else {
 648                         // Send this block on to the servers.
 649                         {
 650                                 lock_guard<mutex> lock(stats_mutex);
 651                                 stats.data_bytes_received += size;
 652                         }
 653                         char *inner_data = pending_data.data() + sizeof(metacube2_block_header);
 654                         if (flags & METACUBE_FLAGS_HEADER) {
 655                                 stream_header = string(inner_data, inner_data + size);
 656                                 for (int stream_index : stream_indices) {
 657                                         servers->set_header(stream_index, http_header, stream_header);
 658                                 }
 659                         }
 660                         for (int stream_index : stream_indices) {
 661                                 servers->add_data(stream_index, inner_data, size, flags, next_block_pts);
 662                         }
 663                         next_block_pts = RationalPTS();
 664                 }
 665
 666                 // Consume the block. This isn't the most efficient way of dealing with things
 667                 // should we have many blocks, but these routines don't need to be too efficient
 668                 // anyway.
 669                 pending_data.erase(pending_data.begin(), pending_data.begin() + sizeof(metacube2_block_header) + size);
 670                 has_metacube_header = false;
 671         }
 672 }
 673
 674 void HTTPInput::drop_pending_data(size_t num_bytes)
 675 {
 676         if (num_bytes == 0) {
 677                 return;
 678         }
 679         log(WARNING, "[%s] Dropping %lld junk bytes; not a Metacube2 stream, or data was dropped from the middle of the stream.",
 680                 url.c_str(), (long long)num_bytes);
 681         assert(pending_data.size() >= num_bytes);
 682         pending_data.erase(pending_data.begin(), pending_data.begin() + num_bytes);
 683 }
 684
 685 void HTTPInput::add_destination(int stream_index)
 686 {
 687         stream_indices.push_back(stream_index);
 688         servers->set_header(stream_index, http_header, stream_header);
 689 }
 690
 691 InputStats HTTPInput::get_stats() const
 692 {
 693         lock_guard<mutex> lock(stats_mutex);
 694         return stats;
 695 }
 696
 697 void HTTPInput::process_metacube_metadata_block(const metacube2_block_header &hdr, const char *payload, uint32_t payload_size)
 698 {
 699         if (payload_size < sizeof(uint64_t)) {
 700                 log(WARNING, "[%s] Undersized Metacube metadata block (%d bytes); corrupted header?",
 701                         url.c_str(), payload_size);
 702                 return;
 703         }
 704
 705         uint64_t type = be64toh(*(const uint64_t *)payload);
 706         if (type == METACUBE_METADATA_TYPE_ENCODER_TIMESTAMP) {
 707                 timespec now;
 708                 clock_gettime(CLOCK_REALTIME, &now);
 709
 710                 const metacube2_timestamp_packet *pkt = (const metacube2_timestamp_packet *)payload;
 711                 if (payload_size != sizeof(*pkt)) {
 712                         log(WARNING, "[%s] Metacube timestamp block of wrong size (%d bytes); ignoring.",
 713                                 url.c_str(), payload_size);
 714                         return;
 715                 }
 716
 717                 double elapsed = now.tv_sec - be64toh(pkt->tv_sec) +
 718                         1e-9 * (now.tv_nsec - long(be64toh(pkt->tv_nsec)));
 719                 {
 720                         lock_guard<mutex> lock(stats_mutex);
 721                         stats.latency_sec = elapsed;
 722                 }
 723         } else if (type == METACUBE_METADATA_TYPE_NEXT_BLOCK_PTS) {
 724                 const metacube2_pts_packet *pkt = (const metacube2_pts_packet *)payload;
 725                 if (payload_size != sizeof(*pkt)) {
 726                         log(WARNING, "[%s] Metacube pts block of wrong size (%d bytes); ignoring.",
 727                                 url.c_str(), payload_size);
 728                         return;
 729                 }
 730                 next_block_pts.pts = be64toh(pkt->pts);
 731                 next_block_pts.timebase_num = be64toh(pkt->timebase_num);
 732                 next_block_pts.timebase_den = be64toh(pkt->timebase_den);
 733         } else {
 734                 // Unknown metadata block, ignore
 735                 log(INFO, "[%s] Metadata block %llu\n", url.c_str(), type);
 736                 return;
 737         }
 738 }