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

   1 #include <assert.h>
   2 #include <errno.h>
   3 #include <getopt.h>
   4 #include <limits.h>
   5 #include <signal.h>
   6 #include <stddef.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <sys/time.h>
  11 #include <sys/wait.h>
  12 #include <systemd/sd-daemon.h>
  13 #include <unistd.h>
  14 #include <algorithm>
  15 #include <map>
  16 #include <set>
  17 #include <string>
  18 #include <utility>
  19 #include <vector>
  20
  21 #include "acceptor.h"
  22 #include "accesslog.h"
  23 #include "config.h"
  24 #include "input.h"
  25 #include "input_stats.h"
  26 #include "log.h"
  27 #include "sa_compare.h"
  28 #include "serverpool.h"
  29 #include "state.pb.h"
  30 #include "stats.h"
  31 #include "stream.h"
  32 #include "util.h"
  33 #include "version.h"
  34
  35 using namespace std;
  36
  37 AccessLogThread *access_log = NULL;
  38 ServerPool *servers = NULL;
  39 volatile bool hupped = false;
  40 volatile bool stopped = false;
  41
  42 typedef pair<string, Input::Encoding> InputKey;
  43
  44 namespace {
  45
  46 struct OrderByConnectionTime {
  47         bool operator() (const ClientProto &a, const ClientProto &b) const {
  48                 if (a.connect_time_sec() != b.connect_time_sec())
  49                         return a.connect_time_sec() < b.connect_time_sec();
  50                 return a.connect_time_nsec() < b.connect_time_nsec();
  51         }
  52 };
  53
  54 }  // namespace
  55
  56 struct InputWithRefcount {
  57         Input *input;
  58         int refcount;
  59 };
  60
  61 void hup(int signum)
  62 {
  63         hupped = true;
  64         if (signum == SIGINT) {
  65                 stopped = true;
  66         }
  67 }
  68
  69 void do_nothing(int signum)
  70 {
  71 }
  72
  73 CubemapStateProto collect_state(const timespec &serialize_start,
  74                                 const vector<Acceptor *> acceptors,
  75                                 const multimap<InputKey, InputWithRefcount> inputs,
  76                                 ServerPool *servers)
  77 {
  78         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  79         state.set_serialize_start_sec(serialize_start.tv_sec);
  80         state.set_serialize_start_usec(serialize_start.tv_nsec / 1000);
  81
  82         for (size_t i = 0; i < acceptors.size(); ++i) {
  83                 state.add_acceptors()->MergeFrom(acceptors[i]->serialize());
  84         }
  85
  86         for (multimap<InputKey, InputWithRefcount>::const_iterator input_it = inputs.begin();
  87              input_it != inputs.end();
  88              ++input_it) {
  89                 state.add_inputs()->MergeFrom(input_it->second.input->serialize());
  90         }
  91
  92         return state;
  93 }
  94
  95 // Find all port statements in the configuration file, and create acceptors for htem.
  96 vector<Acceptor *> create_acceptors(
  97         const Config &config,
  98         map<sockaddr_in6, Acceptor *, Sockaddr6Compare> *deserialized_acceptors)
  99 {
 100         vector<Acceptor *> acceptors;
 101         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
 102                 const AcceptorConfig &acceptor_config = config.acceptors[i];
 103                 Acceptor *acceptor = NULL;
 104                 map<sockaddr_in6, Acceptor *, Sockaddr6Compare>::iterator deserialized_acceptor_it =
 105                         deserialized_acceptors->find(acceptor_config.addr);
 106                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
 107                         acceptor = deserialized_acceptor_it->second;
 108                         deserialized_acceptors->erase(deserialized_acceptor_it);
 109                 } else {
 110                         int server_sock = create_server_socket(acceptor_config.addr, TCP_SOCKET);
 111                         acceptor = new Acceptor(server_sock, acceptor_config.addr);
 112                 }
 113                 acceptor->run();
 114                 acceptors.push_back(acceptor);
 115         }
 116
 117         // Close all acceptors that are no longer in the configuration file.
 118         for (map<sockaddr_in6, Acceptor *, Sockaddr6Compare>::iterator
 119                  acceptor_it = deserialized_acceptors->begin();
 120              acceptor_it != deserialized_acceptors->end();
 121              ++acceptor_it) {
 122                 acceptor_it->second->close_socket();
 123                 delete acceptor_it->second;
 124         }
 125
 126         return acceptors;
 127 }
 128
 129 void create_config_input(const string &src, Input::Encoding encoding, multimap<InputKey, InputWithRefcount> *inputs)
 130 {
 131         if (src.empty()) {
 132                 return;
 133         }
 134         InputKey key(src, encoding);
 135         if (inputs->count(key) != 0) {
 136                 return;
 137         }
 138
 139         InputWithRefcount iwr;
 140         iwr.input = create_input(src, encoding);
 141         if (iwr.input == NULL) {
 142                 log(ERROR, "did not understand URL '%s' or source encoding was invalid, clients will not get any data.",
 143                         src.c_str());
 144                 return;
 145         }
 146         iwr.refcount = 0;
 147         inputs->insert(make_pair(key, iwr));
 148 }
 149
 150 // Find all streams in the configuration file, and create inputs for them.
 151 void create_config_inputs(const Config &config, multimap<InputKey, InputWithRefcount> *inputs)
 152 {
 153         for (unsigned i = 0; i < config.streams.size(); ++i) {
 154                 const StreamConfig &stream_config = config.streams[i];
 155                 if (stream_config.src != "delete") {
 156                         create_config_input(stream_config.src, Input::Encoding(stream_config.src_encoding), inputs);
 157                 }
 158         }
 159         for (unsigned i = 0; i < config.udpstreams.size(); ++i) {
 160                 const UDPStreamConfig &udpstream_config = config.udpstreams[i];
 161                 create_config_input(udpstream_config.src, Input::Encoding(udpstream_config.src_encoding), inputs);
 162         }
 163 }
 164
 165 void create_streams(const Config &config,
 166                     const set<string> &deserialized_urls,
 167                     multimap<InputKey, InputWithRefcount> *inputs)
 168 {
 169         // HTTP streams.
 170         set<string> expecting_urls = deserialized_urls;
 171         for (unsigned i = 0; i < config.streams.size(); ++i) {
 172                 const StreamConfig &stream_config = config.streams[i];
 173                 int stream_index;
 174
 175                 expecting_urls.erase(stream_config.url);
 176
 177                 // Special-case deleted streams; they were never deserialized in the first place,
 178                 // so just ignore them.
 179                 if (stream_config.src == "delete") {
 180                         continue;
 181                 }
 182
 183                 if (deserialized_urls.count(stream_config.url) == 0) {
 184                         stream_index = servers->add_stream(stream_config.url,
 185                                                            stream_config.backlog_size,
 186                                                            stream_config.prebuffering_bytes,
 187                                                            Stream::Encoding(stream_config.encoding),
 188                                                            Stream::Encoding(stream_config.src_encoding));
 189                 } else {
 190                         stream_index = servers->lookup_stream_by_url(stream_config.url);
 191                         assert(stream_index != -1);
 192                         servers->set_backlog_size(stream_index, stream_config.backlog_size);
 193                         servers->set_prebuffering_bytes(stream_index, stream_config.prebuffering_bytes);
 194                         servers->set_encoding(stream_index,
 195                                               Stream::Encoding(stream_config.encoding));
 196                         servers->set_src_encoding(stream_index,
 197                                                   Stream::Encoding(stream_config.src_encoding));
 198                 }
 199
 200                 servers->set_pacing_rate(stream_index, stream_config.pacing_rate);
 201
 202                 string src = stream_config.src;
 203                 Input::Encoding src_encoding = Input::Encoding(stream_config.src_encoding);
 204                 if (!src.empty()) {
 205                         multimap<InputKey, InputWithRefcount>::iterator input_it = inputs->find(make_pair(src, src_encoding));
 206                         if (input_it != inputs->end()) {
 207                                 input_it->second.input->add_destination(stream_index);
 208                                 ++input_it->second.refcount;
 209                         }
 210                 }
 211         }
 212
 213         // Warn about any streams servers we've lost.
 214         for (set<string>::const_iterator stream_it = expecting_urls.begin();
 215              stream_it != expecting_urls.end();
 216              ++stream_it) {
 217                 string url = *stream_it;
 218                 log(WARNING, "stream '%s' disappeared from the configuration file. "
 219                              "It will not be deleted, but clients will not get any new inputs. "
 220                              "If you really meant to delete it, set src=delete and reload.",
 221                              url.c_str());
 222         }
 223
 224         // UDP streams.
 225         for (unsigned i = 0; i < config.udpstreams.size(); ++i) {
 226                 const UDPStreamConfig &udpstream_config = config.udpstreams[i];
 227                 int stream_index = servers->add_udpstream(
 228                         udpstream_config.dst,
 229                         udpstream_config.pacing_rate,
 230                         udpstream_config.ttl,
 231                         udpstream_config.multicast_iface_index);
 232
 233                 string src = udpstream_config.src;
 234                 Input::Encoding src_encoding = Input::Encoding(udpstream_config.src_encoding);
 235                 if (!src.empty()) {
 236                         multimap<InputKey, InputWithRefcount>::iterator input_it = inputs->find(make_pair(src, src_encoding));
 237                         assert(input_it != inputs->end());
 238                         input_it->second.input->add_destination(stream_index);
 239                         ++input_it->second.refcount;
 240                 }
 241         }
 242
 243         // HTTP gen204 endpoints.
 244         for (unsigned i = 0; i < config.pings.size(); ++i) {
 245                 const Gen204Config &ping_config = config.pings[i];
 246                 servers->add_gen204(ping_config.url, ping_config.allow_origin);
 247         }
 248 }
 249
 250 void open_logs(const vector<LogConfig> &log_destinations)
 251 {
 252         for (size_t i = 0; i < log_destinations.size(); ++i) {
 253                 if (log_destinations[i].type == LogConfig::LOG_TYPE_FILE) {
 254                         add_log_destination_file(log_destinations[i].filename);
 255                 } else if (log_destinations[i].type == LogConfig::LOG_TYPE_CONSOLE) {
 256                         add_log_destination_console();
 257                 } else if (log_destinations[i].type == LogConfig::LOG_TYPE_SYSLOG) {
 258                         add_log_destination_syslog();
 259                 } else {
 260                         assert(false);
 261                 }
 262         }
 263         start_logging();
 264 }
 265
 266 bool dry_run_config(const string &argv0, const string &config_filename)
 267 {
 268         char *argv0_copy = strdup(argv0.c_str());
 269         char *config_filename_copy = strdup(config_filename.c_str());
 270
 271         pid_t pid = fork();
 272         switch (pid) {
 273         case -1:
 274                 log_perror("fork()");
 275                 free(argv0_copy);
 276                 free(config_filename_copy);
 277                 return false;
 278         case 0:
 279                 // Child.
 280                 execlp(argv0_copy, argv0_copy, "--test-config", config_filename_copy, NULL);
 281                 log_perror(argv0_copy);
 282                 _exit(1);
 283         default:
 284                 // Parent.
 285                 break;
 286         }
 287
 288         free(argv0_copy);
 289         free(config_filename_copy);
 290
 291         int status;
 292         pid_t err;
 293         do {
 294                 err = waitpid(pid, &status, 0);
 295         } while (err == -1 && errno == EINTR);
 296
 297         if (err == -1) {
 298                 log_perror("waitpid()");
 299                 return false;
 300         }
 301
 302         return (WIFEXITED(status) && WEXITSTATUS(status) == 0);
 303 }
 304
 305 void find_deleted_streams(const Config &config, set<string> *deleted_urls)
 306 {
 307         for (unsigned i = 0; i < config.streams.size(); ++i) {
 308                 const StreamConfig &stream_config = config.streams[i];
 309                 if (stream_config.src == "delete") {
 310                         log(INFO, "Deleting stream '%s'.", stream_config.url.c_str());
 311                         deleted_urls->insert(stream_config.url);
 312                 }
 313         }
 314 }
 315
 316 int main(int argc, char **argv)
 317 {
 318         signal(SIGHUP, hup);
 319         signal(SIGINT, hup);
 320         signal(SIGUSR1, do_nothing);  // Used in internal signalling.
 321         signal(SIGPIPE, SIG_IGN);
 322
 323         // Parse options.
 324         int state_fd = -1;
 325         bool test_config = false;
 326         for ( ;; ) {
 327                 static const option long_options[] = {
 328                         { "state", required_argument, 0, 's' },
 329                         { "test-config", no_argument, 0, 't' },
 330                         { 0, 0, 0, 0 }
 331                 };
 332                 int option_index = 0;
 333                 int c = getopt_long(argc, argv, "s:t", long_options, &option_index);
 334
 335                 if (c == -1) {
 336                         break;
 337                 }
 338                 switch (c) {
 339                 case 's':
 340                         state_fd = atoi(optarg);
 341                         break;
 342                 case 't':
 343                         test_config = true;
 344                         break;
 345                 default:
 346                         fprintf(stderr, "Unknown option '%s'\n", argv[option_index]);
 347                         exit(1);
 348                 }
 349         }
 350
 351         string config_filename = "cubemap.config";
 352         if (optind < argc) {
 353                 config_filename = argv[optind++];
 354         }
 355
 356         // Canonicalize argv[0] and config_filename.
 357         char argv0_canon[PATH_MAX];
 358         char config_filename_canon[PATH_MAX];
 359
 360         if (realpath("/proc/self/exe", argv0_canon) == NULL) {
 361                 log_perror(argv[0]);
 362                 exit(1);
 363         }
 364         if (realpath(config_filename.c_str(), config_filename_canon) == NULL) {
 365                 log_perror(config_filename.c_str());
 366                 exit(1);
 367         }
 368
 369         // Now parse the configuration file.
 370         Config config;
 371         if (!parse_config(config_filename_canon, &config)) {
 372                 exit(1);
 373         }
 374         if (test_config) {
 375                 exit(0);
 376         }
 377
 378         // Ideally we'd like to daemonize only when we've started up all threads etc.,
 379         // but daemon() forks, which is not good in multithreaded software, so we'll
 380         // have to do it here.
 381         if (config.daemonize) {
 382                 if (daemon(0, 0) == -1) {
 383                         log_perror("daemon");
 384                         exit(1);
 385                 }
 386         }
 387
 388 start:
 389         // Open logs as soon as possible.
 390         open_logs(config.log_destinations);
 391
 392         log(INFO, "Cubemap " SERVER_VERSION " starting.");
 393         if (config.access_log_file.empty()) {
 394                 // Create a dummy logger.
 395                 access_log = new AccessLogThread();
 396         } else {
 397                 access_log = new AccessLogThread(config.access_log_file);
 398         }
 399         access_log->run();
 400
 401         servers = new ServerPool(config.num_servers);
 402
 403         // Find all the streams that are to be deleted.
 404         set<string> deleted_urls;
 405         find_deleted_streams(config, &deleted_urls);
 406
 407         CubemapStateProto loaded_state;
 408         timespec serialize_start;
 409         set<string> deserialized_urls;
 410         map<sockaddr_in6, Acceptor *, Sockaddr6Compare> deserialized_acceptors;
 411         multimap<InputKey, InputWithRefcount> inputs;  // multimap due to older versions without deduplication.
 412         if (state_fd != -1) {
 413                 log(INFO, "Deserializing state from previous process...");
 414                 string serialized;
 415                 if (!read_tempfile_and_close(state_fd, &serialized)) {
 416                         exit(1);
 417                 }
 418                 if (!loaded_state.ParseFromString(serialized)) {
 419                         log(ERROR, "Failed deserialization of state.");
 420                         exit(1);
 421                 }
 422
 423                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 424                 serialize_start.tv_nsec = loaded_state.serialize_start_usec() * 1000ull;
 425
 426                 // Deserialize the streams.
 427                 map<string, string> stream_headers_for_url;  // See below.
 428                 for (int i = 0; i < loaded_state.streams_size(); ++i) {
 429                         const StreamProto &stream = loaded_state.streams(i);
 430
 431                         if (deleted_urls.count(stream.url()) != 0) {
 432                                 // Delete the stream backlogs.
 433                                 for (int j = 0; j < stream.data_fds_size(); ++j) {
 434                                         safe_close(stream.data_fds(j));
 435                                 }
 436                         } else {
 437                                 vector<int> data_fds;
 438                                 for (int j = 0; j < stream.data_fds_size(); ++j) {
 439                                         data_fds.push_back(stream.data_fds(j));
 440                                 }
 441
 442                                 servers->add_stream_from_serialized(stream, data_fds);
 443                                 deserialized_urls.insert(stream.url());
 444
 445                                 stream_headers_for_url.insert(make_pair(stream.url(), stream.stream_header()));
 446                         }
 447                 }
 448
 449                 // Deserialize the inputs. Note that we don't actually add them to any stream yet.
 450                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 451                         InputProto serialized_input = loaded_state.inputs(i);
 452
 453                         InputWithRefcount iwr;
 454                         iwr.input = create_input(serialized_input);
 455                         iwr.refcount = 0;
 456
 457                         Input::Encoding src_encoding = serialized_input.is_metacube_encoded() ?
 458                                 Input::INPUT_ENCODING_METACUBE :
 459                                 Input::INPUT_ENCODING_RAW;
 460                         InputKey key(serialized_input.url(), src_encoding);
 461                         inputs.insert(make_pair(key, iwr));
 462                 }
 463
 464                 // Deserialize the acceptors.
 465                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 466                         sockaddr_in6 sin6 = extract_address_from_acceptor_proto(loaded_state.acceptors(i));
 467                         deserialized_acceptors.insert(make_pair(
 468                                 sin6,
 469                                 new Acceptor(loaded_state.acceptors(i))));
 470                 }
 471
 472                 log(INFO, "Deserialization done.");
 473         }
 474
 475         // Add any new inputs coming from the config.
 476         create_config_inputs(config, &inputs);
 477
 478         // Find all streams in the configuration file, create them, and connect to the inputs.
 479         create_streams(config, deserialized_urls, &inputs);
 480         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 481
 482         // Convert old-style timestamps to new-style timestamps for all clients;
 483         // this simplifies the sort below.
 484         {
 485                 timespec now_monotonic;
 486                 if (clock_gettime(CLOCK_MONOTONIC_COARSE, &now_monotonic) == -1) {
 487                         log(ERROR, "clock_gettime(CLOCK_MONOTONIC_COARSE) failed.");
 488                         exit(1);
 489                 }
 490                 long delta_sec = now_monotonic.tv_sec - time(NULL);
 491
 492                 for (int i = 0; i < loaded_state.clients_size(); ++i) {
 493                         ClientProto* client = loaded_state.mutable_clients(i);
 494                         if (client->has_connect_time_old()) {
 495                                 client->set_connect_time_sec(client->connect_time_old() + delta_sec);
 496                                 client->set_connect_time_nsec(now_monotonic.tv_nsec);
 497                                 client->clear_connect_time_old();
 498                         }
 499                 }
 500         }
 501
 502         // Put back the existing clients. It doesn't matter which server we
 503         // allocate them to, so just do round-robin. However, we need to sort them
 504         // by connection time first, since add_client_serialized() expects that.
 505         sort(loaded_state.mutable_clients()->begin(),
 506              loaded_state.mutable_clients()->end(),
 507              OrderByConnectionTime());
 508         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 509                 if (deleted_urls.count(loaded_state.clients(i).url()) != 0) {
 510                         safe_close(loaded_state.clients(i).sock());
 511                 } else {
 512                         servers->add_client_from_serialized(loaded_state.clients(i));
 513                 }
 514         }
 515
 516         servers->run();
 517
 518         // Now delete all inputs that are longer in use, and start the others.
 519         for (multimap<InputKey, InputWithRefcount>::iterator input_it = inputs.begin();
 520              input_it != inputs.end(); ) {
 521                 if (input_it->second.refcount == 0) {
 522                         if (input_it->first.second == Input::INPUT_ENCODING_RAW) {
 523                                 log(WARNING, "Raw input '%s' no longer in use, closing.",
 524                                     input_it->first.first.c_str());
 525                         } else {
 526                                 assert(input_it->first.second == Input::INPUT_ENCODING_METACUBE);
 527                                 log(WARNING, "Metacube input '%s' no longer in use, closing.",
 528                                     input_it->first.first.c_str());
 529                         }
 530                         input_it->second.input->close_socket();
 531                         delete input_it->second.input;
 532                         inputs.erase(input_it++);
 533                 } else {
 534                         input_it->second.input->run();
 535                         ++input_it;
 536                 }
 537         }
 538
 539         // Start writing statistics.
 540         StatsThread *stats_thread = NULL;
 541         if (!config.stats_file.empty()) {
 542                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 543                 stats_thread->run();
 544         }
 545
 546         InputStatsThread *input_stats_thread = NULL;
 547         if (!config.input_stats_file.empty()) {
 548                 vector<Input*> inputs_no_refcount;
 549                 for (multimap<InputKey, InputWithRefcount>::iterator input_it = inputs.begin();
 550                      input_it != inputs.end(); ++input_it) {
 551                         inputs_no_refcount.push_back(input_it->second.input);
 552                 }
 553
 554                 input_stats_thread = new InputStatsThread(config.input_stats_file, config.input_stats_interval, inputs_no_refcount);
 555                 input_stats_thread->run();
 556         }
 557
 558         timespec server_start;
 559         int err = clock_gettime(CLOCK_MONOTONIC, &server_start);
 560         assert(err != -1);
 561         if (state_fd != -1) {
 562                 // Measure time from we started deserializing (below) to now, when basically everything
 563                 // is up and running. This is, in other words, a conservative estimate of how long our
 564                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 565                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 566                         1e-9 * (server_start.tv_nsec - serialize_start.tv_nsec);
 567                 log(INFO, "Re-exec happened in approx. %.0f ms.", glitch_time * 1000.0);
 568         }
 569
 570         sd_notify(0, "READY=1");
 571
 572         while (!hupped) {
 573                 usleep(100000);
 574         }
 575
 576         if (stopped) {
 577                 sd_notify(0, "STOPPING=1");
 578         } else {
 579                 sd_notify(0, "RELOADING=1");
 580         }
 581
 582         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 583         err = clock_gettime(CLOCK_MONOTONIC, &serialize_start);
 584         assert(err != -1);
 585
 586         if (input_stats_thread != NULL) {
 587                 input_stats_thread->stop();
 588                 delete input_stats_thread;
 589         }
 590         if (stats_thread != NULL) {
 591                 stats_thread->stop();
 592                 delete stats_thread;
 593         }
 594         for (size_t i = 0; i < acceptors.size(); ++i) {
 595                 acceptors[i]->stop();
 596         }
 597         for (multimap<InputKey, InputWithRefcount>::iterator input_it = inputs.begin();
 598              input_it != inputs.end();
 599              ++input_it) {
 600                 input_it->second.input->stop();
 601         }
 602         servers->stop();
 603
 604         CubemapStateProto state;
 605         if (stopped) {
 606                 log(INFO, "Shutting down.");
 607         } else {
 608                 log(INFO, "Serializing state and re-execing...");
 609                 state = collect_state(
 610                         serialize_start, acceptors, inputs, servers);
 611                 string serialized;
 612                 state.SerializeToString(&serialized);
 613                 state_fd = make_tempfile(serialized);
 614                 if (state_fd == -1) {
 615                         exit(1);
 616                 }
 617         }
 618         delete servers;
 619
 620         access_log->stop();
 621         delete access_log;
 622         shut_down_logging();
 623
 624         if (stopped) {
 625                 exit(0);
 626         }
 627
 628         // OK, so the signal was SIGHUP. Check that the new config is okay, then exec the new binary.
 629         if (!dry_run_config(argv0_canon, config_filename_canon)) {
 630                 open_logs(config.log_destinations);
 631                 log(ERROR, "%s --test-config failed. Restarting old version instead of new.", argv[0]);
 632                 hupped = false;
 633                 shut_down_logging();
 634                 goto start;
 635         }
 636
 637         char buf[16];
 638         sprintf(buf, "%d", state_fd);
 639
 640         for ( ;; ) {
 641                 execlp(argv0_canon, argv0_canon, config_filename_canon, "--state", buf, NULL);
 642                 open_logs(config.log_destinations);
 643                 log_perror("execlp");
 644                 log(ERROR, "re-exec of %s failed. Waiting 0.2 seconds and trying again...", argv0_canon);
 645                 shut_down_logging();
 646                 usleep(200000);
 647         }
 648 }