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 "tlse.h"
  22
  23 #include "acceptor.h"
  24 #include "accesslog.h"
  25 #include "config.h"
  26 #include "input.h"
  27 #include "input_stats.h"
  28 #include "log.h"
  29 #include "sa_compare.h"
  30 #include "serverpool.h"
  31 #include "state.pb.h"
  32 #include "stats.h"
  33 #include "stream.h"
  34 #include "util.h"
  35 #include "version.h"
  36
  37 using namespace std;
  38
  39 AccessLogThread *access_log = nullptr;
  40 ServerPool *servers = nullptr;
  41 volatile bool hupped = false;
  42 volatile bool stopped = false;
  43
  44 typedef pair<string, Input::Encoding> InputKey;
  45
  46 namespace {
  47
  48 struct OrderByConnectionTime {
  49         bool operator() (const ClientProto &a, const ClientProto &b) const {
  50                 if (a.connect_time_sec() != b.connect_time_sec())
  51                         return a.connect_time_sec() < b.connect_time_sec();
  52                 return a.connect_time_nsec() < b.connect_time_nsec();
  53         }
  54 };
  55
  56 // An arbitrary ordering.
  57 struct AcceptorConfigCompare {
  58         bool operator() (const AcceptorConfig &a, const AcceptorConfig &b) const {
  59                 int cmp = a.certificate_chain.compare(b.certificate_chain);
  60                 if (cmp != 0) {
  61                         return cmp < 0;
  62                 }
  63
  64                 cmp = a.private_key.compare(b.private_key);
  65                 if (cmp != 0) {
  66                         return cmp < 0;
  67                 }
  68
  69                 return Sockaddr6Compare()(a.addr, b.addr);
  70         }
  71 };
  72
  73 }  // namespace
  74
  75 struct InputWithRefcount {
  76         Input *input;
  77         int refcount;
  78 };
  79
  80 void hup(int signum)
  81 {
  82         hupped = true;
  83         if (signum == SIGINT) {
  84                 stopped = true;
  85         }
  86 }
  87
  88 void do_nothing(int signum)
  89 {
  90 }
  91
  92 CubemapStateProto collect_state(const timespec &serialize_start,
  93                                 const vector<Acceptor *> acceptors,
  94                                 const multimap<InputKey, InputWithRefcount> inputs,
  95                                 ServerPool *servers)
  96 {
  97         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  98         state.set_serialize_start_sec(serialize_start.tv_sec);
  99         state.set_serialize_start_usec(serialize_start.tv_nsec / 1000);
 100
 101         for (Acceptor *acceptor : acceptors) {
 102                 state.add_acceptors()->MergeFrom(acceptor->serialize());
 103         }
 104
 105         for (const auto &key_and_input_with_refcount : inputs) {
 106                 state.add_inputs()->MergeFrom(key_and_input_with_refcount.second.input->serialize());
 107         }
 108
 109         return state;
 110 }
 111
 112 // Find all port statements in the configuration file, and create acceptors for them.
 113 vector<Acceptor *> create_acceptors(
 114         const Config &config,
 115         map<AcceptorConfig, Acceptor *, AcceptorConfigCompare> *deserialized_acceptors)
 116 {
 117         vector<Acceptor *> acceptors;
 118         for (const AcceptorConfig &acceptor_config : config.acceptors) {
 119                 Acceptor *acceptor = nullptr;
 120                 const auto deserialized_acceptor_it = deserialized_acceptors->find(acceptor_config);
 121                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
 122                         acceptor = deserialized_acceptor_it->second;
 123                         deserialized_acceptors->erase(deserialized_acceptor_it);
 124                 } else {
 125                         int server_sock = create_server_socket(acceptor_config.addr, TCP_SOCKET);
 126                         acceptor = new Acceptor(server_sock, acceptor_config.addr,
 127                                                 acceptor_config.certificate_chain,
 128                                                 acceptor_config.private_key);
 129                 }
 130                 acceptor->run();
 131                 acceptors.push_back(acceptor);
 132         }
 133
 134         // Close all acceptors that are no longer in the configuration file.
 135         for (auto &config_and_acceptor : *deserialized_acceptors) {
 136                 config_and_acceptor.second->close_socket();
 137                 delete config_and_acceptor.second;
 138         }
 139
 140         return acceptors;
 141 }
 142
 143 void create_config_input(const string &src, Input::Encoding encoding, multimap<InputKey, InputWithRefcount> *inputs)
 144 {
 145         if (src.empty()) {
 146                 return;
 147         }
 148         InputKey key(src, encoding);
 149         if (inputs->count(key) != 0) {
 150                 return;
 151         }
 152
 153         InputWithRefcount iwr;
 154         iwr.input = create_input(src, encoding);
 155         if (iwr.input == nullptr) {
 156                 log(ERROR, "did not understand URL '%s' or source encoding was invalid, clients will not get any data.",
 157                         src.c_str());
 158                 return;
 159         }
 160         iwr.refcount = 0;
 161         inputs->insert(make_pair(key, iwr));
 162 }
 163
 164 // Find all streams in the configuration file, and create inputs for them.
 165 void create_config_inputs(const Config &config, multimap<InputKey, InputWithRefcount> *inputs)
 166 {
 167         for (const StreamConfig &stream_config : config.streams) {
 168                 if (stream_config.src == "delete") {
 169                         // Ignored for pre-1.4.0 configuration compatibility.
 170                         continue;
 171                 }
 172                 create_config_input(stream_config.src, Input::Encoding(stream_config.src_encoding), inputs);
 173         }
 174         for (const UDPStreamConfig &udpstream_config : config.udpstreams) {
 175                 create_config_input(udpstream_config.src, Input::INPUT_ENCODING_RAW, inputs);
 176         }
 177 }
 178
 179 void create_streams(const Config &config,
 180                     const set<string> &deserialized_urls,
 181                     multimap<InputKey, InputWithRefcount> *inputs)
 182 {
 183         // HTTP streams.
 184         set<string> expecting_urls = deserialized_urls;
 185         for (const StreamConfig &stream_config : config.streams) {
 186                 int stream_index;
 187
 188                 expecting_urls.erase(stream_config.url);
 189
 190                 if (stream_config.src == "delete") {
 191                         // Ignored for pre-1.4.0 configuration compatibility.
 192                         continue;
 193                 }
 194
 195                 if (deserialized_urls.count(stream_config.url) == 0) {
 196                         stream_index = servers->add_stream(stream_config.url,
 197                                                            stream_config.hls_url,
 198                                                            stream_config.backlog_size,
 199                                                            stream_config.prebuffering_bytes,
 200                                                            Stream::Encoding(stream_config.encoding),
 201                                                            Stream::Encoding(stream_config.src_encoding),
 202                                                            stream_config.hls_frag_duration,
 203                                                            stream_config.hls_backlog_margin,
 204                                                            stream_config.allow_origin);
 205                 } else {
 206                         stream_index = servers->lookup_stream_by_url(stream_config.url);
 207                         assert(stream_index != -1);
 208                         servers->set_backlog_size(stream_index, stream_config.backlog_size);
 209                         if (!stream_config.hls_url.empty()) {
 210                                 servers->register_hls_url(stream_index, stream_config.hls_url);
 211                         }
 212                         servers->set_prebuffering_bytes(stream_index, stream_config.prebuffering_bytes);
 213                         servers->set_encoding(stream_index,
 214                                               Stream::Encoding(stream_config.encoding));
 215                         servers->set_src_encoding(stream_index,
 216                                                   Stream::Encoding(stream_config.src_encoding));
 217                         servers->set_hls_frag_duration(stream_index, stream_config.hls_frag_duration);
 218                         servers->set_hls_backlog_margin(stream_index, stream_config.hls_backlog_margin);
 219                         servers->set_allow_origin(stream_index, stream_config.allow_origin);
 220                 }
 221
 222                 servers->set_pacing_rate(stream_index, stream_config.pacing_rate);
 223
 224                 string src = stream_config.src;
 225                 Input::Encoding src_encoding = Input::Encoding(stream_config.src_encoding);
 226                 if (!src.empty()) {
 227                         const auto input_it = inputs->find(make_pair(src, src_encoding));
 228                         if (input_it != inputs->end()) {
 229                                 input_it->second.input->add_destination(stream_index);
 230                                 ++input_it->second.refcount;
 231                         }
 232                 }
 233         }
 234
 235         // Warn about any streams servers we've lost.
 236         for (const string &url : expecting_urls) {
 237                 log(WARNING, "stream '%s' disappeared from the configuration file. "
 238                              "It will not be deleted, but clients will not get any new inputs. "
 239                              "If you really meant to delete it, set src=delete and reload.",
 240                              url.c_str());
 241         }
 242
 243         // UDP streams.
 244         for (const UDPStreamConfig &udpstream_config : config.udpstreams) {
 245                 int stream_index = servers->add_udpstream(
 246                         udpstream_config.dst,
 247                         udpstream_config.pacing_rate,
 248                         udpstream_config.ttl,
 249                         udpstream_config.multicast_iface_index);
 250
 251                 string src = udpstream_config.src;
 252                 if (!src.empty()) {
 253                         auto input_it = inputs->find(make_pair(src, Input::INPUT_ENCODING_RAW));
 254                         assert(input_it != inputs->end());
 255                         input_it->second.input->add_destination(stream_index);
 256                         ++input_it->second.refcount;
 257                 }
 258         }
 259
 260         // HTTP gen204 endpoints.
 261         for (const Gen204Config &ping_config : config.pings) {
 262                 servers->add_gen204(ping_config.url, ping_config.allow_origin);
 263         }
 264 }
 265
 266 void open_logs(const vector<LogConfig> &log_destinations)
 267 {
 268         for (const LogConfig &log_destination : log_destinations) {
 269                 if (log_destination.type == LogConfig::LOG_TYPE_FILE) {
 270                         add_log_destination_file(log_destination.filename);
 271                 } else if (log_destination.type == LogConfig::LOG_TYPE_CONSOLE) {
 272                         add_log_destination_console();
 273                 } else if (log_destination.type == LogConfig::LOG_TYPE_SYSLOG) {
 274                         add_log_destination_syslog();
 275                 } else {
 276                         assert(false);
 277                 }
 278         }
 279         start_logging();
 280 }
 281
 282 bool dry_run_config(const string &argv0, const string &config_filename)
 283 {
 284         char *argv0_copy = strdup(argv0.c_str());
 285         char *config_filename_copy = strdup(config_filename.c_str());
 286
 287         pid_t pid = fork();
 288         switch (pid) {
 289         case -1:
 290                 log_perror("fork()");
 291                 free(argv0_copy);
 292                 free(config_filename_copy);
 293                 return false;
 294         case 0:
 295                 // Child.
 296                 execlp(argv0_copy, argv0_copy, "--test-config", config_filename_copy, nullptr);
 297                 log_perror(argv0_copy);
 298                 _exit(1);
 299         default:
 300                 // Parent.
 301                 break;
 302         }
 303
 304         free(argv0_copy);
 305         free(config_filename_copy);
 306
 307         int status;
 308         pid_t err;
 309         do {
 310                 err = waitpid(pid, &status, 0);
 311         } while (err == -1 && errno == EINTR);
 312
 313         if (err == -1) {
 314                 log_perror("waitpid()");
 315                 return false;
 316         }
 317
 318         return (WIFEXITED(status) && WEXITSTATUS(status) == 0);
 319 }
 320
 321 void find_all_streams(const Config &config, set<string> *all_urls)
 322 {
 323         for (const StreamConfig &stream_config : config.streams) {
 324                 if (stream_config.src == "delete") {
 325                         log(WARNING, "stream '%s' has src=delete; ignoring it. Since Cubemap 1.4.0, you do not "
 326                                      "need to set src=delete to delete streams anymore; just delete them from "
 327                                      "the configuration file.",
 328                                      stream_config.url.c_str());
 329                 } else {
 330                         all_urls->insert(stream_config.url);
 331                 }
 332         }
 333 }
 334
 335 int main(int argc, char **argv)
 336 {
 337         signal(SIGHUP, hup);
 338         signal(SIGINT, hup);
 339         signal(SIGUSR1, do_nothing);  // Used in internal signalling.
 340         signal(SIGPIPE, SIG_IGN);
 341
 342         tls_init();
 343
 344         // Parse options.
 345         int state_fd = -1;
 346         bool test_config = false;
 347         for ( ;; ) {
 348                 static const option long_options[] = {
 349                         { "state", required_argument, 0, 's' },
 350                         { "test-config", no_argument, 0, 't' },
 351                         { 0, 0, 0, 0 }
 352                 };
 353                 int option_index = 0;
 354                 int c = getopt_long(argc, argv, "s:t", long_options, &option_index);
 355
 356                 if (c == -1) {
 357                         break;
 358                 }
 359                 switch (c) {
 360                 case 's':
 361                         state_fd = atoi(optarg);
 362                         break;
 363                 case 't':
 364                         test_config = true;
 365                         break;
 366                 default:
 367                         fprintf(stderr, "Unknown option '%s'\n", argv[option_index]);
 368                         exit(1);
 369                 }
 370         }
 371
 372         string config_filename = "cubemap.config";
 373         if (optind < argc) {
 374                 config_filename = argv[optind++];
 375         }
 376
 377         // Canonicalize argv[0] and config_filename.
 378         char argv0_canon[PATH_MAX];
 379         char config_filename_canon[PATH_MAX];
 380
 381         if (realpath("/proc/self/exe", argv0_canon) == nullptr) {
 382                 log_perror(argv[0]);
 383                 exit(1);
 384         }
 385         if (realpath(config_filename.c_str(), config_filename_canon) == nullptr) {
 386                 log_perror(config_filename.c_str());
 387                 exit(1);
 388         }
 389
 390         // Now parse the configuration file.
 391         Config config;
 392         if (!parse_config(config_filename_canon, &config)) {
 393                 exit(1);
 394         }
 395         if (test_config) {
 396                 exit(0);
 397         }
 398
 399         // Ideally we'd like to daemonize only when we've started up all threads etc.,
 400         // but daemon() forks, which is not good in multithreaded software, so we'll
 401         // have to do it here.
 402         if (config.daemonize) {
 403                 if (daemon(0, 0) == -1) {
 404                         log_perror("daemon");
 405                         exit(1);
 406                 }
 407         }
 408
 409 start:
 410         // Open logs as soon as possible.
 411         open_logs(config.log_destinations);
 412
 413         log(INFO, "Cubemap " SERVER_VERSION " starting.");
 414         if (config.access_log_file.empty()) {
 415                 // Create a dummy logger.
 416                 access_log = new AccessLogThread();
 417         } else {
 418                 access_log = new AccessLogThread(config.access_log_file);
 419         }
 420         access_log->run();
 421
 422         servers = new ServerPool(config.num_servers);
 423
 424         // Find all the streams that are to be kept.
 425         set<string> all_urls;
 426         find_all_streams(config, &all_urls);
 427
 428         CubemapStateProto loaded_state;
 429         timespec serialize_start;
 430         set<string> deserialized_urls;
 431         map<AcceptorConfig, Acceptor *, AcceptorConfigCompare> deserialized_acceptors;
 432         multimap<InputKey, InputWithRefcount> inputs;  // multimap due to older versions without deduplication.
 433         if (state_fd != -1) {
 434                 log(INFO, "Deserializing state from previous process...");
 435                 string serialized;
 436                 if (!read_tempfile_and_close(state_fd, &serialized)) {
 437                         exit(1);
 438                 }
 439                 if (!loaded_state.ParseFromString(serialized)) {
 440                         log(ERROR, "Failed deserialization of state.");
 441                         exit(1);
 442                 }
 443
 444                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 445                 serialize_start.tv_nsec = loaded_state.serialize_start_usec() * 1000ull;
 446
 447                 // Deserialize the streams.
 448                 map<string, string> stream_headers_for_url;  // See below.
 449                 for (const StreamProto &stream : loaded_state.streams()) {
 450                         if (all_urls.count(stream.url()) == 0) {
 451                                 // Delete the stream backlogs.
 452                                 log(INFO, "Deleting stream '%s'.", stream.url().c_str());
 453                                 for (const int fd : stream.data_fds()) {
 454                                         safe_close(fd);
 455                                 }
 456                         } else {
 457                                 vector<int> data_fds;
 458                                 for (const int fd : stream.data_fds()) {
 459                                         data_fds.push_back(fd);
 460                                 }
 461
 462                                 servers->add_stream_from_serialized(stream, data_fds);
 463                                 deserialized_urls.insert(stream.url());
 464
 465                                 stream_headers_for_url.insert(make_pair(stream.url(), stream.stream_header()));
 466                         }
 467                 }
 468
 469                 // Deserialize the inputs. Note that we don't actually add them to any stream yet.
 470                 for (const InputProto &serialized_input : loaded_state.inputs()) {
 471                         InputWithRefcount iwr;
 472                         iwr.input = create_input(serialized_input);
 473                         iwr.refcount = 0;
 474
 475                         Input::Encoding src_encoding = serialized_input.is_metacube_encoded() ?
 476                                 Input::INPUT_ENCODING_METACUBE :
 477                                 Input::INPUT_ENCODING_RAW;
 478                         InputKey key(serialized_input.url(), src_encoding);
 479                         inputs.insert(make_pair(key, iwr));
 480                 }
 481
 482                 // Deserialize the acceptors.
 483                 for (const AcceptorProto &serialized_acceptor : loaded_state.acceptors()) {
 484                         AcceptorConfig config;
 485                         config.addr = extract_address_from_acceptor_proto(serialized_acceptor);
 486                         config.certificate_chain = serialized_acceptor.certificate_chain();
 487                         config.private_key = serialized_acceptor.private_key();
 488                         deserialized_acceptors.insert(make_pair(
 489                                 config,
 490                                 new Acceptor(serialized_acceptor)));
 491                 }
 492
 493                 log(INFO, "Deserialization done.");
 494         }
 495
 496         // Add any new inputs coming from the config.
 497         create_config_inputs(config, &inputs);
 498
 499         // Find all streams in the configuration file, create them, and connect to the inputs.
 500         create_streams(config, deserialized_urls, &inputs);
 501         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 502
 503         // Make all the servers create TLS contexts for every TLS keypair we have.
 504         for (Acceptor *acceptor : acceptors) {
 505                 if (acceptor->is_tls()) {
 506                         servers->create_tls_context_for_acceptor(acceptor);
 507                 }
 508         }
 509
 510         // Allocate strings for the short responses.
 511         vector<shared_ptr<const string>> short_response_pool;
 512         for (const ShortResponsePool &str : loaded_state.short_response_pool()) {
 513                 short_response_pool.emplace_back(new string(str.header_or_short_response()));
 514         }
 515
 516         // Put back the existing clients. It doesn't matter which server we
 517         // allocate them to, so just do round-robin. However, we need to sort them
 518         // by connection time first, since add_client_serialized() expects that.
 519         sort(loaded_state.mutable_clients()->begin(),
 520              loaded_state.mutable_clients()->end(),
 521              OrderByConnectionTime());
 522         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 523                 if (all_urls.count(loaded_state.clients(i).url()) == 0) {
 524                         safe_close(loaded_state.clients(i).sock());
 525                 } else {
 526                         servers->add_client_from_serialized(loaded_state.clients(i), short_response_pool);
 527                 }
 528         }
 529
 530         short_response_pool.clear();  // No longer needed; the clients have their own refcounts now.
 531
 532         servers->run();
 533
 534         // Now delete all inputs that are longer in use, and start the others.
 535         for (auto input_it = inputs.begin(); input_it != inputs.end(); ) {
 536                 if (input_it->second.refcount == 0) {
 537                         if (input_it->first.second == Input::INPUT_ENCODING_RAW) {
 538                                 log(WARNING, "Raw input '%s' no longer in use, closing.",
 539                                     input_it->first.first.c_str());
 540                         } else {
 541                                 assert(input_it->first.second == Input::INPUT_ENCODING_METACUBE);
 542                                 log(WARNING, "Metacube input '%s' no longer in use, closing.",
 543                                     input_it->first.first.c_str());
 544                         }
 545                         input_it->second.input->close_socket();
 546                         delete input_it->second.input;
 547                         inputs.erase(input_it++);
 548                 } else {
 549                         input_it->second.input->run();
 550                         ++input_it;
 551                 }
 552         }
 553
 554         // Start writing statistics.
 555         unique_ptr<StatsThread> stats_thread;
 556         if (!config.stats_file.empty()) {
 557                 stats_thread.reset(new StatsThread(config.stats_file, config.stats_interval));
 558                 stats_thread->run();
 559         }
 560
 561         unique_ptr<InputStatsThread> input_stats_thread;
 562         if (!config.input_stats_file.empty()) {
 563                 vector<Input*> inputs_no_refcount;
 564                 for (const auto &key_and_input_with_refcount : inputs) {
 565                         inputs_no_refcount.push_back(key_and_input_with_refcount.second.input);
 566                 }
 567
 568                 input_stats_thread.reset(new InputStatsThread(config.input_stats_file, config.input_stats_interval, inputs_no_refcount));
 569                 input_stats_thread->run();
 570         }
 571
 572         timespec server_start;
 573         int err = clock_gettime(CLOCK_MONOTONIC, &server_start);
 574         assert(err != -1);
 575         if (state_fd != -1) {
 576                 // Measure time from we started deserializing (below) to now, when basically everything
 577                 // is up and running. This is, in other words, a conservative estimate of how long our
 578                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 579                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 580                         1e-9 * (server_start.tv_nsec - serialize_start.tv_nsec);
 581                 log(INFO, "Re-exec happened in approx. %.0f ms.", glitch_time * 1000.0);
 582         }
 583
 584         sd_notify(0, "READY=1");
 585
 586         while (!hupped) {
 587                 usleep(100000);
 588         }
 589
 590         if (stopped) {
 591                 sd_notify(0, "STOPPING=1");
 592         } else {
 593                 sd_notify(0, "RELOADING=1");
 594         }
 595
 596         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 597         err = clock_gettime(CLOCK_MONOTONIC, &serialize_start);
 598         assert(err != -1);
 599
 600         if (input_stats_thread != nullptr) {
 601                 input_stats_thread->stop();
 602                 input_stats_thread.reset();
 603         }
 604         if (stats_thread != nullptr) {
 605                 stats_thread->stop();
 606                 stats_thread.reset();
 607         }
 608         for (Acceptor *acceptor : acceptors) {
 609                 acceptor->stop();
 610         }
 611         for (const auto &key_and_input_with_refcount : inputs) {
 612                 key_and_input_with_refcount.second.input->stop();
 613         }
 614         servers->stop();
 615
 616         CubemapStateProto state;
 617         if (stopped) {
 618                 log(INFO, "Shutting down.");
 619         } else {
 620                 log(INFO, "Serializing state and re-execing...");
 621                 state = collect_state(
 622                         serialize_start, acceptors, inputs, servers);
 623                 string serialized;
 624                 state.SerializeToString(&serialized);
 625                 state_fd = make_tempfile(serialized);
 626                 if (state_fd == -1) {
 627                         exit(1);
 628                 }
 629         }
 630         delete servers;
 631
 632         access_log->stop();
 633         delete access_log;
 634         shut_down_logging();
 635
 636         if (stopped) {
 637                 exit(0);
 638         }
 639
 640         // OK, so the signal was SIGHUP. Check that the new config is okay, then exec the new binary.
 641         if (!dry_run_config(argv0_canon, config_filename_canon)) {
 642                 open_logs(config.log_destinations);
 643                 log(ERROR, "%s --test-config failed. Restarting old version instead of new.", argv[0]);
 644                 hupped = false;
 645                 shut_down_logging();
 646                 goto start;
 647         }
 648
 649         char buf[16];
 650         sprintf(buf, "%d", state_fd);
 651
 652         for ( ;; ) {
 653                 execlp(argv0_canon, argv0_canon, config_filename_canon, "--state", buf, nullptr);
 654                 open_logs(config.log_destinations);
 655                 log_perror("execlp");
 656                 log(ERROR, "re-exec of %s failed. Waiting 0.2 seconds and trying again...", argv0_canon);
 657                 shut_down_logging();
 658                 usleep(200000);
 659         }
 660 }