qmeventd/qmeventd.c

   1 // SPDX-License-Identifier: AGPL-3.0-or-later
   2 /*
   3     Copyright (C) 2018 - 2021 Proxmox Server Solutions GmbH
   4
   5     Author: Dominik Csapak <d.csapak@proxmox.com>
   6     Author: Stefan Reiter <s.reiter@proxmox.com>
   7
   8     Description:
   9
  10     qmeventd listens on a given socket, and waits for qemu processes to
  11     connect. After accepting a connection qmeventd waits for shutdown events
  12     followed by the closing of the socket. Once that happens `qm cleanup` will
  13     be executed with following three arguments:
  14     VMID <graceful> <guest>
  15     Where `graceful` can be `1` or `0` depending if shutdown event was observed
  16     before the socket got closed. The second parameter `guest` is also boolean
  17     `1` or `0` depending if the shutdown was requested from the guest OS
  18     (i.e., the "inside").
  19 */
  20
  21 #ifndef _GNU_SOURCE
  22 #define _GNU_SOURCE
  23 #endif
  24
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #include <gmodule.h>
  28 #include <json.h>
  29 #include <signal.h>
  30 #include <stdbool.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <sys/epoll.h>
  35 #include <sys/socket.h>
  36 #include <sys/types.h>
  37 #include <sys/un.h>
  38 #include <sys/wait.h>
  39 #include <unistd.h>
  40 #include <time.h>
  41
  42 #include "qmeventd.h"
  43
  44 #define DEFAULT_KILL_TIMEOUT 60
  45
  46 static int verbose = 0;
  47 static int kill_timeout = DEFAULT_KILL_TIMEOUT;
  48 static int epoll_fd = 0;
  49 static const char *progname;
  50 GHashTable *vm_clients; // key=vmid (freed on remove), value=*Client (free manually)
  51 GSList *forced_cleanups;
  52 static int needs_cleanup = 0;
  53
  54 /*
  55  * Helper functions
  56  */
  57
  58 static void
  59 usage()
  60 {
  61     fprintf(stderr, "Usage: %s [-f] [-v] PATH\n", progname);
  62     fprintf(stderr, "  -f       run in foreground (default: false)\n");
  63     fprintf(stderr, "  -v       verbose (default: false)\n");
  64     fprintf(stderr, "  -t <s>   kill timeout (default: %ds)\n", DEFAULT_KILL_TIMEOUT);
  65     fprintf(stderr, "  PATH     use PATH for socket\n");
  66 }
  67
  68 static pid_t
  69 get_pid_from_fd(int fd)
  70 {
  71     struct ucred credentials = { .pid = 0, .uid = 0, .gid = 0 };
  72     socklen_t len = sizeof(struct ucred);
  73     log_neg(getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &credentials, &len), "getsockopt");
  74     return credentials.pid;
  75 }
  76
  77 /*
  78  * parses the vmid from the qemu.slice entry of /proc/<pid>/cgroup
  79  */
  80 static unsigned long
  81 get_vmid_from_pid(pid_t pid)
  82 {
  83     char filename[32] = { 0 };
  84     int len = snprintf(filename, sizeof(filename), "/proc/%d/cgroup", pid);
  85     if (len < 0) {
  86         fprintf(stderr, "error during snprintf for %d: %s\n", pid,
  87                 strerror(errno));
  88         return 0;
  89     }
  90     if ((size_t)len >= sizeof(filename)) {
  91         fprintf(stderr, "error: pid %d too long\n", pid);
  92         return 0;
  93     }
  94     FILE *fp = fopen(filename, "re");
  95     if (fp == NULL) {
  96         fprintf(stderr, "error opening %s: %s\n", filename, strerror(errno));
  97         return 0;
  98     }
  99
 100     unsigned long vmid = 0;
 101     char *buf = NULL;
 102     size_t buflen = 0;
 103
 104     while (getline(&buf, &buflen, fp) >= 0) {
 105         char *cgroup_path = strrchr(buf, ':');
 106         if (!cgroup_path) {
 107             fprintf(stderr, "unexpected cgroup entry %s\n", buf);
 108             goto ret;
 109         }
 110         cgroup_path++;
 111
 112         if (strncmp(cgroup_path, "/qemu.slice/", 12)) {
 113             continue;
 114         }
 115
 116         char *vmid_start = strrchr(buf, '/');
 117         if (!vmid_start) {
 118             fprintf(stderr, "unexpected cgroup entry %s\n", buf);
 119             goto ret;
 120         }
 121         vmid_start++;
 122
 123         if (vmid_start[0] == '-' || vmid_start[0] == '\0') {
 124             fprintf(stderr, "invalid vmid in cgroup entry %s\n", buf);
 125             goto ret;
 126         }
 127
 128         errno = 0;
 129         char *endptr = NULL;
 130         vmid = strtoul(vmid_start, &endptr, 10);
 131         if (errno != 0) {
 132             fprintf(stderr, "error parsing vmid for %d: %s\n", pid, strerror(errno));
 133             vmid = 0;
 134         } else if (*endptr != '.') {
 135             fprintf(stderr, "unexpected cgroup entry %s\n", buf);
 136             vmid = 0;
 137         }
 138
 139         goto ret;
 140     }
 141
 142     if (errno) {
 143         fprintf(stderr, "error parsing vmid for %d: %s\n", pid, strerror(errno));
 144     } else {
 145         fprintf(stderr, "error parsing vmid for %d: no matching qemu.slice cgroup entry\n", pid);
 146     }
 147
 148 ret:
 149     free(buf);
 150     fclose(fp);
 151     return vmid;
 152 }
 153
 154 static bool
 155 must_write(int fd, const char *buf, size_t len)
 156 {
 157     ssize_t wlen;
 158     do {
 159         wlen = write(fd, buf, len);
 160     } while (wlen < 0 && errno == EINTR);
 161
 162     return (wlen == (ssize_t)len);
 163 }
 164
 165 /*
 166  * qmp handling functions
 167  */
 168
 169 static void
 170 send_qmp_cmd(struct Client *client, const char *buf, size_t len)
 171 {
 172     if (!must_write(client->fd, buf, len - 1)) {
 173         fprintf(stderr, "%s: cannot send QMP message\n", client->qemu.vmid);
 174         cleanup_client(client);
 175     }
 176 }
 177
 178 void
 179 handle_qmp_handshake(struct Client *client)
 180 {
 181     VERBOSE_PRINT("pid%d: got QMP handshake, assuming QEMU client\n", client->pid);
 182
 183     // extract vmid from cmdline, now that we know it's a QEMU process
 184     unsigned long vmid = get_vmid_from_pid(client->pid);
 185     int res = snprintf(client->qemu.vmid, sizeof(client->qemu.vmid), "%lu", vmid);
 186     if (vmid == 0 || res < 0 || res >= (int)sizeof(client->qemu.vmid)) {
 187         fprintf(stderr, "could not get vmid from pid %d\n", client->pid);
 188         cleanup_client(client);
 189         return;
 190     }
 191
 192     VERBOSE_PRINT("pid%d: assigned VMID: %s\n", client->pid, client->qemu.vmid);
 193     client->type = CLIENT_QEMU;
 194     if(!g_hash_table_insert(vm_clients, strdup(client->qemu.vmid), client)) {
 195         // not fatal, just means backup handling won't work
 196         fprintf(stderr, "%s: could not insert client into VMID->client table\n",
 197                 client->qemu.vmid);
 198     }
 199
 200     static const char qmp_answer[] = "{\"execute\":\"qmp_capabilities\"}\n";
 201     send_qmp_cmd(client, qmp_answer, sizeof(qmp_answer));
 202 }
 203
 204 void
 205 handle_qmp_event(struct Client *client, struct json_object *obj)
 206 {
 207     struct json_object *event;
 208     if (!json_object_object_get_ex(obj, "event", &event)) {
 209         return;
 210     }
 211     VERBOSE_PRINT("%s: got QMP event: %s\n", client->qemu.vmid, json_object_get_string(event));
 212
 213     if (client->state == STATE_TERMINATING) {
 214         // QEMU sometimes sends a second SHUTDOWN after SIGTERM, ignore
 215         VERBOSE_PRINT("%s: event was after termination, ignoring\n", client->qemu.vmid);
 216         return;
 217     }
 218
 219     // event, check if shutdown and get guest parameter
 220     if (!strcmp(json_object_get_string(event), "SHUTDOWN")) {
 221         client->qemu.graceful = 1;
 222         struct json_object *data;
 223         struct json_object *guest;
 224         if (json_object_object_get_ex(obj, "data", &data) &&
 225             json_object_object_get_ex(data, "guest", &guest))
 226         {
 227             client->qemu.guest = (unsigned short)json_object_get_boolean(guest);
 228         }
 229
 230         // check if a backup is running and kill QEMU process if not
 231         terminate_check(client);
 232     }
 233 }
 234
 235 void
 236 terminate_check(struct Client *client)
 237 {
 238     if (client->state != STATE_IDLE) {
 239         // if we're already in a request, queue this one until after
 240         VERBOSE_PRINT("%s: terminate_check queued\n", client->qemu.vmid);
 241         client->qemu.term_check_queued = true;
 242         return;
 243     }
 244
 245     client->qemu.term_check_queued = false;
 246
 247     VERBOSE_PRINT("%s: query-status\n", client->qemu.vmid);
 248     client->state = STATE_EXPECT_STATUS_RESP;
 249     static const char qmp_req[] = "{\"execute\":\"query-status\"}\n";
 250     send_qmp_cmd(client, qmp_req, sizeof(qmp_req));
 251 }
 252
 253 void
 254 handle_qmp_return(struct Client *client, struct json_object *data, bool error)
 255 {
 256     if (error) {
 257         const char *msg = "n/a";
 258         struct json_object *desc;
 259         if (json_object_object_get_ex(data, "desc", &desc)) {
 260             msg = json_object_get_string(desc);
 261         }
 262         fprintf(stderr, "%s: received error from QMP: %s\n",
 263                 client->qemu.vmid, msg);
 264         client->state = STATE_IDLE;
 265         goto out;
 266     }
 267
 268     struct json_object *status;
 269     json_bool has_status = data &&
 270         json_object_object_get_ex(data, "status", &status);
 271
 272     bool active = false;
 273     if (has_status) {
 274         const char *status_str = json_object_get_string(status);
 275         active = status_str &&
 276             (!strcmp(status_str, "running") || !strcmp(status_str, "paused"));
 277     }
 278
 279     switch (client->state) {
 280         case STATE_EXPECT_STATUS_RESP:
 281             client->state = STATE_IDLE;
 282             if (active) {
 283                 VERBOSE_PRINT("%s: got status: VM is active\n", client->qemu.vmid);
 284             } else if (!client->qemu.backup) {
 285                 terminate_client(client);
 286             } else {
 287                 // if we're in a backup, don't do anything, vzdump will notify
 288                 // us when the backup finishes
 289                 VERBOSE_PRINT("%s: not active, but running backup - keep alive\n",
 290                               client->qemu.vmid);
 291             }
 292             break;
 293
 294         // this means we received the empty return from our handshake answer
 295         case STATE_HANDSHAKE:
 296             client->state = STATE_IDLE;
 297             VERBOSE_PRINT("%s: QMP handshake complete\n", client->qemu.vmid);
 298             break;
 299
 300         // we expect an empty return object after sending quit
 301         case STATE_TERMINATING:
 302             break;
 303         case STATE_IDLE:
 304             VERBOSE_PRINT("%s: spurious return value received\n",
 305                           client->qemu.vmid);
 306             break;
 307     }
 308
 309 out:
 310     if (client->qemu.term_check_queued) {
 311         terminate_check(client);
 312     }
 313 }
 314
 315 /*
 316  * VZDump specific client functions
 317  */
 318
 319 void
 320 handle_vzdump_handshake(struct Client *client, struct json_object *data)
 321 {
 322     client->state = STATE_IDLE;
 323
 324     struct json_object *vmid_obj;
 325     json_bool has_vmid = data && json_object_object_get_ex(data, "vmid", &vmid_obj);
 326
 327     if (!has_vmid) {
 328         VERBOSE_PRINT("pid%d: invalid vzdump handshake: no vmid\n", client->pid);
 329         return;
 330     }
 331
 332     const char *vmid_str = json_object_get_string(vmid_obj);
 333
 334     if (!vmid_str) {
 335         VERBOSE_PRINT("pid%d: invalid vzdump handshake: vmid is not a string\n", client->pid);
 336         return;
 337     }
 338
 339     int res = snprintf(client->vzdump.vmid, sizeof(client->vzdump.vmid), "%s", vmid_str);
 340     if (res < 0 || res >= (int)sizeof(client->vzdump.vmid)) {
 341         VERBOSE_PRINT("pid%d: invalid vzdump handshake: vmid too long or invalid\n", client->pid);
 342         return;
 343     }
 344
 345     struct Client *vmc = (struct Client*) g_hash_table_lookup(vm_clients, client->vzdump.vmid);
 346     if (vmc) {
 347         vmc->qemu.backup = true;
 348
 349         // only mark as VZDUMP once we have set everything up, otherwise 'cleanup'
 350         // might try to access an invalid value
 351         client->type = CLIENT_VZDUMP;
 352         VERBOSE_PRINT("%s: vzdump backup started\n", client->vzdump.vmid);
 353     } else {
 354         VERBOSE_PRINT("%s: vzdump requested backup start for unregistered VM\n", client->vzdump.vmid);
 355     }
 356 }
 357
 358 /*
 359  * client management functions
 360  */
 361
 362 void
 363 add_new_client(int client_fd)
 364 {
 365     struct Client *client = calloc(sizeof(struct Client), 1);
 366     if (client == NULL) {
 367         fprintf(stderr, "could not add new client - allocation failed!\n");
 368         fflush(stderr);
 369         return;
 370     }
 371     client->state = STATE_HANDSHAKE;
 372     client->type = CLIENT_NONE;
 373     client->fd = client_fd;
 374     client->pid = get_pid_from_fd(client_fd);
 375     if (client->pid == 0) {
 376         fprintf(stderr, "could not get pid from client\n");
 377         goto err;
 378     }
 379
 380     struct epoll_event ev;
 381     ev.events = EPOLLIN;
 382     ev.data.ptr = client;
 383     int res = epoll_ctl(epoll_fd, EPOLL_CTL_ADD, client_fd, &ev);
 384     if (res < 0) {
 385         perror("epoll_ctl client add");
 386         goto err;
 387     }
 388
 389     VERBOSE_PRINT("added new client, pid: %d\n", client->pid);
 390
 391     return;
 392 err:
 393     (void)close(client_fd);
 394     free(client);
 395 }
 396
 397 static void
 398 cleanup_qemu_client(struct Client *client)
 399 {
 400     unsigned short graceful = client->qemu.graceful;
 401     unsigned short guest = client->qemu.guest;
 402     char vmid[sizeof(client->qemu.vmid)];
 403     strncpy(vmid, client->qemu.vmid, sizeof(vmid));
 404     g_hash_table_remove(vm_clients, &vmid); // frees key, ignore errors
 405     VERBOSE_PRINT("%s: executing cleanup (graceful: %d, guest: %d)\n",
 406                 vmid, graceful, guest);
 407
 408     int pid = fork();
 409     if (pid < 0) {
 410         fprintf(stderr, "fork failed: %s\n", strerror(errno));
 411         return;
 412     }
 413     if (pid == 0) {
 414         char *script = "/usr/sbin/qm";
 415
 416         char *args[] = {
 417             script,
 418             "cleanup",
 419             vmid,
 420             graceful ? "1" : "0",
 421             guest    ? "1" : "0",
 422             NULL
 423         };
 424
 425         execvp(script, args);
 426         perror("execvp");
 427         _exit(1);
 428     }
 429 }
 430
 431 void
 432 cleanup_client(struct Client *client)
 433 {
 434     log_neg(epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->fd, NULL), "epoll del");
 435     (void)close(client->fd);
 436
 437     struct Client *vmc;
 438     switch (client->type) {
 439         case CLIENT_QEMU:
 440             cleanup_qemu_client(client);
 441             break;
 442
 443         case CLIENT_VZDUMP:
 444             vmc = (struct Client*) g_hash_table_lookup(vm_clients, client->vzdump.vmid);
 445             if (vmc) {
 446                 VERBOSE_PRINT("%s: backup ended\n", client->vzdump.vmid);
 447                 vmc->qemu.backup = false;
 448                 terminate_check(vmc);
 449             }
 450             break;
 451
 452         case CLIENT_NONE:
 453             // do nothing, only close socket
 454             break;
 455     }
 456
 457     if (client->pidfd > 0) {
 458         (void)close(client->pidfd);
 459     }
 460     VERBOSE_PRINT("removing %s from forced cleanups\n", client->qemu.vmid);
 461     forced_cleanups = g_slist_remove(forced_cleanups, client);
 462     free(client);
 463 }
 464
 465 void
 466 terminate_client(struct Client *client)
 467 {
 468     VERBOSE_PRINT("%s: terminating client (pid %d)\n", client->qemu.vmid, client->pid);
 469
 470     client->state = STATE_TERMINATING;
 471
 472     // open a pidfd before kill for later cleanup
 473     int pidfd = pidfd_open(client->pid, 0);
 474     if (pidfd < 0) {
 475         switch (errno) {
 476             case ESRCH:
 477                 // process already dead for some reason, cleanup done
 478                 VERBOSE_PRINT("%s: failed to open pidfd, process already dead (pid %d)\n",
 479                               client->qemu.vmid, client->pid);
 480                 return;
 481
 482             // otherwise fall back to just using the PID directly, but don't
 483             // print if we only failed because we're running on an older kernel
 484             case ENOSYS:
 485                 break;
 486             default:
 487                 perror("failed to open QEMU pidfd for cleanup");
 488                 break;
 489         }
 490     }
 491
 492     // try to send a 'quit' command first, fallback to SIGTERM of the pid
 493     static const char qmp_quit_command[] = "{\"execute\":\"quit\"}\n";
 494     VERBOSE_PRINT("%s: sending 'quit' via QMP\n", client->qemu.vmid);
 495     if (!must_write(client->fd, qmp_quit_command, sizeof(qmp_quit_command) - 1)) {
 496         VERBOSE_PRINT("%s: sending 'SIGTERM' to pid %d\n", client->qemu.vmid, client->pid);
 497         int err = kill(client->pid, SIGTERM);
 498         log_neg(err, "kill");
 499     }
 500
 501     time_t timeout = time(NULL) + kill_timeout;
 502
 503     client->pidfd = pidfd;
 504     client->timeout = timeout;
 505
 506     forced_cleanups = g_slist_prepend(forced_cleanups, (void *)client);
 507     needs_cleanup = 1;
 508 }
 509
 510 void
 511 handle_client(struct Client *client)
 512 {
 513     VERBOSE_PRINT("pid%d: entering handle\n", client->pid);
 514     ssize_t len;
 515     do {
 516         len = read(client->fd, (client->buf+client->buflen),
 517                    sizeof(client->buf) - client->buflen);
 518     } while (len < 0 && errno == EINTR);
 519
 520     if (len < 0) {
 521         if (!(errno == EAGAIN || errno == EWOULDBLOCK)) {
 522             log_neg((int)len, "read");
 523             cleanup_client(client);
 524         }
 525         return;
 526     } else if (len == 0) {
 527         VERBOSE_PRINT("pid%d: got EOF\n", client->pid);
 528         cleanup_client(client);
 529         return;
 530     }
 531
 532     VERBOSE_PRINT("pid%d: read %ld bytes\n", client->pid, len);
 533     client->buflen += len;
 534
 535     struct json_tokener *tok = json_tokener_new();
 536     struct json_object *jobj = NULL;
 537     enum json_tokener_error jerr = json_tokener_success;
 538     while (jerr == json_tokener_success && client->buflen != 0) {
 539         jobj = json_tokener_parse_ex(tok, client->buf, (int)client->buflen);
 540         jerr = json_tokener_get_error(tok);
 541         unsigned int offset = (unsigned int)tok->char_offset;
 542         switch (jerr) {
 543             case json_tokener_success:
 544                 // move rest from buffer to front
 545                 memmove(client->buf, client->buf + offset, client->buflen - offset);
 546                 client->buflen -= offset;
 547                 if (json_object_is_type(jobj, json_type_object)) {
 548                     struct json_object *obj;
 549                     if (json_object_object_get_ex(jobj, "QMP", &obj)) {
 550                         handle_qmp_handshake(client);
 551                     } else if (json_object_object_get_ex(jobj, "event", &obj)) {
 552                         handle_qmp_event(client, jobj);
 553                     } else if (json_object_object_get_ex(jobj, "return", &obj)) {
 554                         handle_qmp_return(client, obj, false);
 555                     } else if (json_object_object_get_ex(jobj, "error", &obj)) {
 556                         handle_qmp_return(client, obj, true);
 557                     } else if (json_object_object_get_ex(jobj, "vzdump", &obj)) {
 558                         handle_vzdump_handshake(client, obj);
 559                     } // else ignore message
 560                 }
 561                 break;
 562             case json_tokener_continue:
 563                 if (client->buflen >= sizeof(client->buf)) {
 564                     VERBOSE_PRINT("pid%d: msg too large, discarding buffer\n", client->pid);
 565                     memset(client->buf, 0, sizeof(client->buf));
 566                     client->buflen = 0;
 567                 } // else we have enough space try again after next read
 568                 break;
 569             default:
 570                 VERBOSE_PRINT("pid%d: parse error: %d, discarding buffer\n", client->pid, jerr);
 571                 memset(client->buf, 0, client->buflen);
 572                 client->buflen = 0;
 573                 break;
 574         }
 575         json_object_put(jobj);
 576     }
 577     json_tokener_free(tok);
 578 }
 579
 580 static void
 581 sigkill(void *ptr, void *time_ptr)
 582 {
 583     struct Client *data = ptr;
 584     int err;
 585
 586     if (data->timeout != 0 && data->timeout > *(time_t *)time_ptr) {
 587         return;
 588     }
 589
 590     if (data->pidfd > 0) {
 591         err = pidfd_send_signal(data->pidfd, SIGKILL, NULL, 0);
 592         (void)close(data->pidfd);
 593         data->pidfd = -1;
 594     } else {
 595         err = kill(data->pid, SIGKILL);
 596     }
 597
 598     if (err < 0) {
 599         if (errno != ESRCH) {
 600             fprintf(stderr, "SIGKILL cleanup of pid '%d' failed - %s\n",
 601                     data->pid, strerror(errno));
 602         }
 603     } else {
 604         fprintf(stderr, "cleanup failed, terminating pid '%d' with SIGKILL\n",
 605                 data->pid);
 606     }
 607
 608     data->timeout = 0;
 609
 610     // remove ourselves from the list
 611     forced_cleanups = g_slist_remove(forced_cleanups, ptr);
 612 }
 613
 614 static void
 615 handle_forced_cleanup()
 616 {
 617     if (g_slist_length(forced_cleanups) > 0) {
 618         VERBOSE_PRINT("clearing forced cleanup backlog\n");
 619         time_t cur_time = time(NULL);
 620         g_slist_foreach(forced_cleanups, sigkill, &cur_time);
 621     }
 622     needs_cleanup = g_slist_length(forced_cleanups) > 0;
 623 }
 624
 625 int
 626 main(int argc, char *argv[])
 627 {
 628     int opt;
 629     int daemonize = 1;
 630     char *socket_path = NULL;
 631     progname = argv[0];
 632
 633     while ((opt = getopt(argc, argv, "hfvt:")) != -1) {
 634         switch (opt) {
 635             case 'f':
 636                 daemonize = 0;
 637                 break;
 638             case 'v':
 639                 verbose = 1;
 640                 break;
 641             case 't':
 642                 errno = 0;
 643                 char *endptr = NULL;
 644                 kill_timeout = strtoul(optarg, &endptr, 10);
 645                 if (errno != 0 || *endptr != '\0' || kill_timeout == 0) {
 646                     usage();
 647                     exit(EXIT_FAILURE);
 648                 }
 649                 break;
 650             case 'h':
 651                 usage();
 652                 exit(EXIT_SUCCESS);
 653                 break;
 654             default:
 655                 usage();
 656                 exit(EXIT_FAILURE);
 657         }
 658     }
 659
 660     if (optind >= argc) {
 661         usage();
 662         exit(EXIT_FAILURE);
 663     }
 664
 665     signal(SIGCHLD, SIG_IGN);
 666
 667     socket_path = argv[optind];
 668
 669     int sock = socket(AF_UNIX, SOCK_STREAM, 0);
 670     bail_neg(sock, "socket");
 671
 672     struct sockaddr_un addr;
 673     memset(&addr, 0, sizeof(addr));
 674     addr.sun_family = AF_UNIX;
 675     strncpy(addr.sun_path, socket_path, sizeof(addr.sun_path) - 1);
 676
 677     unlink(socket_path);
 678     bail_neg(bind(sock, (struct sockaddr*)&addr, sizeof(addr)), "bind");
 679
 680     struct epoll_event ev, events[1];
 681     epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 682     bail_neg(epoll_fd, "epoll_create1");
 683
 684     ev.events = EPOLLIN;
 685     ev.data.fd = sock;
 686     bail_neg(epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev), "epoll_ctl");
 687
 688     bail_neg(listen(sock, 10), "listen");
 689
 690     if (daemonize) {
 691         bail_neg(daemon(0, 1), "daemon");
 692     }
 693
 694     vm_clients = g_hash_table_new_full(g_str_hash, g_str_equal, free, NULL);
 695
 696     int nevents;
 697
 698     for(;;) {
 699         nevents = epoll_wait(epoll_fd, events, 1, needs_cleanup ? 10*1000 : -1);
 700         if (nevents < 0 && errno == EINTR) {
 701             continue;
 702         }
 703         bail_neg(nevents, "epoll_wait");
 704
 705         for (int n = 0; n < nevents; n++) {
 706             if (events[n].data.fd == sock) {
 707
 708                 int conn_sock = accept4(sock, NULL, NULL, SOCK_NONBLOCK | SOCK_CLOEXEC);
 709                 log_neg(conn_sock, "accept");
 710                 if (conn_sock > -1) {
 711                     add_new_client(conn_sock);
 712                 }
 713             } else {
 714                 handle_client((struct Client *)events[n].data.ptr);
 715             }
 716         }
 717         handle_forced_cleanup();
 718     }
 719 }