multipathd/uxlsnr.c

   1 /*
   2  * Original author : tridge@samba.org, January 2002
   3  *
   4  * Copyright (c) 2005 Christophe Varoqui
   5  * Copyright (c) 2005 Benjamin Marzinski, Redhat
   6  */
   7
   8 /*
   9  * A simple domain socket listener
  10  */
  11 #define _GNU_SOURCE
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15 #include <stdarg.h>
  16 #include <fcntl.h>
  17 #include <errno.h>
  18 #include <sys/ioctl.h>
  19 #include <sys/types.h>
  20 #include <sys/socket.h>
  21 #include <sys/un.h>
  22 #include <poll.h>
  23 #include <sys/time.h>
  24 #include <signal.h>
  25 #include <stdbool.h>
  26 #include <sys/inotify.h>
  27 #include <sys/eventfd.h>
  28 #include "checkers.h"
  29 #include "debug.h"
  30 #include "vector.h"
  31 #include "structs.h"
  32 #include "structs_vec.h"
  33 #include "uxsock.h"
  34 #include "defaults.h"
  35 #include "config.h"
  36 #include "mpath_cmd.h"
  37 #include "time-util.h"
  38 #include "util.h"
  39
  40 #include "main.h"
  41 #include "cli.h"
  42 #include "uxlsnr.h"
  43 #include "strbuf.h"
  44
  45 /* state of client connection */
  46 enum {
  47         CLT_RECV,
  48         CLT_PARSE,
  49         CLT_LOCKED_WORK,
  50         CLT_WORK,
  51         CLT_SEND,
  52 };
  53
  54 struct client {
  55         struct list_head node;
  56         struct timespec expires;
  57         int state;
  58         int fd;
  59         vector cmdvec;
  60         /* NUL byte at end */
  61         char cmd[_MAX_CMD_LEN + 1];
  62         struct strbuf reply;
  63         struct handler *handler;
  64         size_t cmd_len, len;
  65         int error;
  66         bool is_root;
  67 };
  68
  69 /* Indices for array of poll fds */
  70 enum {
  71         POLLFD_UX = 0,
  72         POLLFD_NOTIFY,
  73         POLLFD_IDLE,
  74         POLLFDS_BASE,
  75 };
  76
  77 #define POLLFD_CHUNK (4096 / sizeof(struct pollfd))
  78 /* Minimum mumber of pollfds to reserve for clients */
  79 #define MIN_POLLS (POLLFD_CHUNK - POLLFDS_BASE)
  80 /*
  81  * Max number of client connections allowed
  82  * During coldplug, there may be a large number of "multipath -u"
  83  * processes connecting.
  84  */
  85 #define MAX_CLIENTS (16384 - POLLFDS_BASE)
  86
  87 /* Compile-time error if POLLFD_CHUNK is too small */
  88 static __attribute__((unused)) char ___a[-(MIN_POLLS <= 0)];
  89
  90 static LIST_HEAD(clients);
  91 static struct pollfd *polls;
  92 static int notify_fd = -1;
  93 static int idle_fd = -1;
  94 static char *watch_config_dir;
  95
  96 static bool _socket_client_is_root(int fd)
  97 {
  98         socklen_t len = 0;
  99         struct ucred uc;
 100
 101         len = sizeof(struct ucred);
 102         if ((fd >= 0) &&
 103             (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &uc, &len) == 0) &&
 104             (uc.uid == 0))
 105                         return true;
 106
 107         /* Treat error as not root client */
 108         return false;
 109 }
 110
 111 /*
 112  * handle a new client joining
 113  */
 114 static void new_client(int ux_sock)
 115 {
 116         struct client *c;
 117         struct sockaddr addr;
 118         socklen_t len = sizeof(addr);
 119         int fd;
 120
 121         fd = accept(ux_sock, &addr, &len);
 122
 123         if (fd == -1)
 124                 return;
 125
 126         c = (struct client *)calloc(1, sizeof(*c));
 127         if (!c) {
 128                 close(fd);
 129                 return;
 130         }
 131         INIT_LIST_HEAD(&c->node);
 132         c->fd = fd;
 133         c->state = CLT_RECV;
 134         c->is_root = _socket_client_is_root(c->fd);
 135
 136         /* put it in our linked list */
 137         list_add_tail(&c->node, &clients);
 138 }
 139
 140 /*
 141  * kill off a dead client
 142  */
 143 static void dead_client(struct client *c)
 144 {
 145         int fd = c->fd;
 146         list_del_init(&c->node);
 147         c->fd = -1;
 148         reset_strbuf(&c->reply);
 149         if (c->cmdvec)
 150                 free_keys(c->cmdvec);
 151         free(c);
 152         close(fd);
 153 }
 154
 155 static void free_polls (void)
 156 {
 157         if (polls)
 158                 free(polls);
 159         polls = NULL;
 160 }
 161
 162 void uxsock_cleanup(void *arg)
 163 {
 164         struct client *client_loop;
 165         struct client *client_tmp;
 166         long ux_sock = (long)arg;
 167
 168         close(ux_sock);
 169         close(notify_fd);
 170         free(watch_config_dir);
 171
 172         list_for_each_entry_safe(client_loop, client_tmp, &clients, node) {
 173                 dead_client(client_loop);
 174         }
 175
 176         cli_exit();
 177         free_polls();
 178 }
 179
 180 void wakeup_cleanup(void *arg)
 181 {
 182         struct mutex_lock *lck = arg;
 183         int fd = idle_fd;
 184
 185         idle_fd = -1;
 186         set_wakeup_fn(lck, NULL);
 187         if (fd != -1)
 188                 close(fd);
 189 }
 190
 191 struct watch_descriptors {
 192         int conf_wd;
 193         int dir_wd;
 194 };
 195
 196 /* failing to set the watch descriptor is o.k. we just miss a warning
 197  * message */
 198 static void reset_watch(int notify_fd, struct watch_descriptors *wds,
 199                         unsigned int *sequence_nr)
 200 {
 201         struct config *conf;
 202         int dir_reset = 0;
 203         int conf_reset = 0;
 204
 205         if (notify_fd == -1)
 206                 return;
 207
 208         conf = get_multipath_config();
 209         /* instead of repeatedly try to reset the inotify watch if
 210          * the config directory or multipath.conf isn't there, just
 211          * do it once per reconfigure */
 212         if (*sequence_nr != conf->sequence_nr) {
 213                 *sequence_nr = conf->sequence_nr;
 214                 if (wds->conf_wd == -1)
 215                         conf_reset = 1;
 216                 if (!watch_config_dir || !conf->config_dir ||
 217                     strcmp(watch_config_dir, conf->config_dir)) {
 218                         dir_reset = 1;
 219                         if (watch_config_dir)
 220                                 free(watch_config_dir);
 221                         if (conf->config_dir)
 222                                 watch_config_dir = strdup(conf->config_dir);
 223                         else
 224                                 watch_config_dir = NULL;
 225                 } else if (wds->dir_wd == -1)
 226                         dir_reset = 1;
 227         }
 228         put_multipath_config(conf);
 229
 230         if (dir_reset) {
 231                 if (wds->dir_wd != -1) {
 232                         inotify_rm_watch(notify_fd, wds->dir_wd);
 233                         wds->dir_wd = -1;
 234                 }
 235                 if (watch_config_dir) {
 236                         wds->dir_wd = inotify_add_watch(notify_fd,
 237                                                         watch_config_dir,
 238                                                         IN_CLOSE_WRITE |
 239                                                         IN_DELETE | IN_ONLYDIR);
 240                         if (wds->dir_wd == -1)
 241                                 condlog(3, "didn't set up notifications on %s: %m", watch_config_dir);
 242                 }
 243         }
 244         if (conf_reset) {
 245                 wds->conf_wd = inotify_add_watch(notify_fd, DEFAULT_CONFIGFILE,
 246                                                  IN_CLOSE_WRITE);
 247                 if (wds->conf_wd == -1)
 248                         condlog(3, "didn't set up notifications on /etc/multipath.conf: %m");
 249         }
 250         return;
 251 }
 252
 253 static void handle_inotify(int fd, struct watch_descriptors *wds)
 254 {
 255         char buff[1024]
 256                 __attribute__ ((aligned(__alignof__(struct inotify_event))));
 257         const struct inotify_event *event;
 258         ssize_t len;
 259         char *ptr;
 260         int got_notify = 0;
 261
 262         for (;;) {
 263                 len = read(fd, buff, sizeof(buff));
 264                 if (len <= 0) {
 265                         if (len < 0 && errno != EAGAIN) {
 266                                 condlog(3, "error reading from inotify_fd");
 267                                 if (wds->conf_wd != -1)
 268                                         inotify_rm_watch(fd, wds->conf_wd);
 269                                 if (wds->dir_wd != -1)
 270                                         inotify_rm_watch(fd, wds->dir_wd);
 271                                 wds->conf_wd = wds->dir_wd = -1;
 272                         }
 273                         break;
 274                 }
 275
 276                 got_notify = 1;
 277                 for (ptr = buff; ptr < buff + len;
 278                      ptr += sizeof(struct inotify_event) + event->len) {
 279                         event = (const struct inotify_event *) ptr;
 280
 281                         if (event->mask & IN_IGNORED) {
 282                                 /* multipathd.conf may have been overwritten.
 283                                  * Try once to reset the notification */
 284                                 if (wds->conf_wd == event->wd)
 285                                         wds->conf_wd = inotify_add_watch(notify_fd, DEFAULT_CONFIGFILE, IN_CLOSE_WRITE);
 286                                 else if (wds->dir_wd == event->wd)
 287                                         wds->dir_wd = -1;
 288                         }
 289                 }
 290         }
 291         if (got_notify)
 292                 condlog(1, "Multipath configuration updated.\nReload multipathd for changes to take effect");
 293 }
 294
 295 static const struct timespec ts_zero = { .tv_sec = 0, };
 296 static const struct timespec ts_max = { .tv_sec = LONG_MAX, .tv_nsec = 999999999 };
 297
 298 static struct timespec *get_soonest_timeout(struct timespec *ts)
 299 {
 300         struct timespec ts_min = ts_max, now;
 301         bool any = false;
 302         struct client *c;
 303
 304         list_for_each_entry(c, &clients, node) {
 305                 if (timespeccmp(&c->expires, &ts_zero) != 0 &&
 306                     timespeccmp(&c->expires, &ts_min) < 0) {
 307                         ts_min = c->expires;
 308                         any = true;
 309                 }
 310         }
 311
 312         if (!any)
 313                 return NULL;
 314
 315         get_monotonic_time(&now);
 316         timespecsub(&ts_min, &now, ts);
 317         if (timespeccmp(ts, &ts_zero) < 0)
 318                 *ts = ts_zero;
 319
 320         condlog(4, "%s: next client expires in %ld.%03lds", __func__,
 321                 (long)ts->tv_sec, ts->tv_nsec / 1000000);
 322         return ts;
 323 }
 324
 325 static bool need_vecs_lock(void)
 326 {
 327         struct client *c;
 328
 329         list_for_each_entry(c, &clients, node) {
 330                 if (c->state == CLT_LOCKED_WORK)
 331                         return true;
 332         }
 333         return false;
 334 }
 335
 336 static int parse_cmd(struct client *c)
 337 {
 338         int r;
 339
 340         r = get_cmdvec(c->cmd, &c->cmdvec);
 341
 342         if (r)
 343                 return -r;
 344
 345         c->handler = find_handler_for_cmdvec(c->cmdvec);
 346
 347         if (!c->handler || !c->handler->fn)
 348                 return -EINVAL;
 349
 350         return r;
 351 }
 352
 353 static int execute_handler(struct client *c, struct vectors *vecs)
 354 {
 355
 356         if (!c->handler || !c->handler->fn)
 357                 return -EINVAL;
 358
 359         return c->handler->fn(c->cmdvec, &c->reply, vecs);
 360 }
 361
 362 static void wakeup_listener(void)
 363 {
 364         uint64_t one = 1;
 365
 366         if (idle_fd != -1 &&
 367             write(idle_fd, &one, sizeof(one)) != sizeof(one))
 368                 condlog(1, "%s: failed", __func__);
 369 }
 370
 371 static void drain_idle_fd(int fd)
 372 {
 373         uint64_t val;
 374         int rc;
 375
 376         rc = read(fd, &val, sizeof(val));
 377         condlog(4, "%s: %d, %"PRIu64, __func__, rc, val);
 378 }
 379
 380 void default_reply(struct client *c, int r)
 381 {
 382         switch(r) {
 383         case -EINVAL:
 384         case -ESRCH:
 385         case -ENOMEM:
 386                 /* return codes from get_cmdvec() */
 387                 genhelp_handler(c->cmd, -r, &c->reply);
 388                 break;
 389         case -EPERM:
 390                 append_strbuf_str(&c->reply,
 391                                   "permission deny: need to be root\n");
 392                 break;
 393         case -ETIMEDOUT:
 394                 append_strbuf_str(&c->reply, "timeout\n");
 395                 break;
 396         case 0:
 397                 append_strbuf_str(&c->reply, "ok\n");
 398                 break;
 399         default:
 400                 /* cli_handler functions return 1 on unspecified error */
 401                 append_strbuf_str(&c->reply, "fail\n");
 402                 break;
 403         }
 404 }
 405
 406 static void set_client_state(struct client *c, int state)
 407 {
 408         switch(state)
 409         {
 410         case CLT_RECV:
 411                 reset_strbuf(&c->reply);
 412                 memset(c->cmd, '\0', sizeof(c->cmd));
 413                 c->expires = ts_zero;
 414                 c->error = 0;
 415                 /* fallthrough */
 416         case CLT_SEND:
 417                 /* reuse these fields for next data transfer */
 418                 c->len = c->cmd_len = 0;
 419                 break;
 420         default:
 421                 break;
 422         }
 423         c->state = state;
 424 }
 425
 426 enum {
 427         STM_CONT,
 428         STM_BREAK,
 429 };
 430
 431 static int client_state_machine(struct client *c, struct vectors *vecs,
 432                                 short revents)
 433 {
 434         ssize_t n;
 435
 436         condlog(4, "%s: cli[%d] poll=%x state=%d cmd=\"%s\" repl \"%s\"", __func__,
 437                 c->fd, revents, c->state, c->cmd, get_strbuf_str(&c->reply));
 438
 439         switch (c->state) {
 440         case CLT_RECV:
 441                 if (!(revents & POLLIN))
 442                         return STM_BREAK;
 443                 if (c->cmd_len == 0) {
 444                         size_t len;
 445                         /*
 446                          * We got POLLIN; assume that at least the length can
 447                          * be read immediately.
 448                          */
 449                         get_monotonic_time(&c->expires);
 450                         c->expires.tv_sec += uxsock_timeout / 1000;
 451                         c->expires.tv_nsec += (uxsock_timeout % 1000) * 1000000;
 452                         normalize_timespec(&c->expires);
 453                         n = recv(c->fd, &len, sizeof(len), 0);
 454                         if (n < (ssize_t)sizeof(len)) {
 455                                 condlog(1, "%s: cli[%d]: failed to receive reply len: %zd",
 456                                         __func__, c->fd, n);
 457                                 c->error = -ECONNRESET;
 458                         } else if (len <= 0 || len > _MAX_CMD_LEN) {
 459                                 condlog(1, "%s: cli[%d]: invalid command length (%zu bytes)",
 460                                         __func__, c->fd, len);
 461                                 c->error = -ECONNRESET;
 462                         } else {
 463                                 c->cmd_len = len;
 464                                 condlog(4, "%s: cli[%d]: connected", __func__, c->fd);
 465                         }
 466                         /* poll for data */
 467                         return STM_BREAK;
 468                 } else if (c->len < c->cmd_len) {
 469                         n = recv(c->fd, c->cmd + c->len, c->cmd_len - c->len, 0);
 470                         if (n <= 0 && errno != EINTR && errno != EAGAIN) {
 471                                 condlog(1, "%s: cli[%d]: error in recv: %m",
 472                                         __func__, c->fd);
 473                                 c->error = -ECONNRESET;
 474                                 return STM_BREAK;
 475                         }
 476                         c->len += n;
 477                         if (c->len < c->cmd_len)
 478                                 /* continue polling */
 479                                 return STM_BREAK;
 480                 }
 481                 condlog(4, "cli[%d]: Got request [%s]", c->fd, c->cmd);
 482                 set_client_state(c, CLT_PARSE);
 483                 return STM_CONT;
 484
 485         case CLT_PARSE:
 486                 c->error = parse_cmd(c);
 487                 if (!c->error) {
 488                         /* Permission check */
 489                         struct key *kw = VECTOR_SLOT(c->cmdvec, 0);
 490
 491                         if (!c->is_root && kw->code != LIST) {
 492                                 c->error = -EPERM;
 493                                 condlog(0, "%s: cli[%d]: unauthorized cmd \"%s\"",
 494                                         __func__, c->fd, c->cmd);
 495                         }
 496                 }
 497                 if (c->error)
 498                         set_client_state(c, CLT_SEND);
 499                 else if (c->handler->locked)
 500                         set_client_state(c, CLT_LOCKED_WORK);
 501                 else
 502                         set_client_state(c, CLT_WORK);
 503                 return STM_CONT;
 504
 505         case CLT_LOCKED_WORK:
 506                 if (trylock(&vecs->lock) == 0) {
 507                         /* don't use cleanup_lock(), lest we wakeup ourselves */
 508                         pthread_cleanup_push_cast(__unlock, &vecs->lock);
 509                         c->error = execute_handler(c, vecs);
 510                         pthread_cleanup_pop(1);
 511                         condlog(4, "%s: cli[%d] grabbed lock", __func__, c->fd);
 512                         free_keys(c->cmdvec);
 513                         c->cmdvec = NULL;
 514                         set_client_state(c, CLT_SEND);
 515                         /* Wait for POLLOUT */
 516                         return STM_BREAK;
 517                 } else {
 518                         condlog(4, "%s: cli[%d] waiting for lock", __func__, c->fd);
 519                         return STM_BREAK;
 520                 }
 521
 522         case CLT_WORK:
 523                 c->error = execute_handler(c, vecs);
 524                 free_keys(c->cmdvec);
 525                 c->cmdvec = NULL;
 526                 set_client_state(c, CLT_SEND);
 527                 /* Wait for POLLOUT */
 528                 return STM_BREAK;
 529
 530         case CLT_SEND:
 531                 if (get_strbuf_len(&c->reply) == 0)
 532                         default_reply(c, c->error);
 533
 534                 if (c->cmd_len == 0) {
 535                         size_t len = get_strbuf_len(&c->reply) + 1;
 536
 537                         if (send(c->fd, &len, sizeof(len), MSG_NOSIGNAL)
 538                             != sizeof(len))
 539                                 c->error = -ECONNRESET;
 540                         c->cmd_len = len;
 541                         return STM_BREAK;
 542                 }
 543
 544                 if (c->len < c->cmd_len) {
 545                         const char *buf = get_strbuf_str(&c->reply);
 546
 547                         n = send(c->fd, buf + c->len, c->cmd_len, MSG_NOSIGNAL);
 548                         if (n == -1) {
 549                                 if (!(errno == EAGAIN || errno == EINTR))
 550                                         c->error = -ECONNRESET;
 551                         } else
 552                                 c->len += n;
 553                 }
 554
 555                 if (c->len >= c->cmd_len) {
 556                         condlog(4, "cli[%d]: Reply [%zu bytes]", c->fd, c->cmd_len);
 557                         set_client_state(c, CLT_RECV);
 558                 }
 559                 return STM_BREAK;
 560
 561         default:
 562                 return STM_BREAK;
 563         }
 564 }
 565
 566 static void check_timeout(struct client *c)
 567 {
 568         struct timespec now;
 569
 570         if (timespeccmp(&c->expires, &ts_zero) == 0)
 571                 return;
 572
 573         get_monotonic_time(&now);
 574         if (timespeccmp(&c->expires, &now) > 0)
 575                 return;
 576
 577         condlog(2, "%s: cli[%d]: timed out at %ld.%03ld", __func__,
 578                 c->fd, (long)c->expires.tv_sec, c->expires.tv_nsec / 1000000);
 579
 580         c->error = -ETIMEDOUT;
 581         set_client_state(c, CLT_SEND);
 582 }
 583
 584 static void handle_client(struct client *c, struct vectors *vecs, short revents)
 585 {
 586         if (revents & (POLLHUP|POLLERR)) {
 587                 c->error = -ECONNRESET;
 588                 return;
 589         }
 590
 591         check_timeout(c);
 592         while (client_state_machine(c, vecs, revents) == STM_CONT);
 593 }
 594
 595 /*
 596  * entry point
 597  */
 598 void *uxsock_listen(long ux_sock, void *trigger_data)
 599 {
 600         sigset_t mask;
 601         int max_pfds = MIN_POLLS + POLLFDS_BASE;
 602         /* conf->sequence_nr will be 1 when uxsock_listen is first called */
 603         unsigned int sequence_nr = 0;
 604         struct watch_descriptors wds = { .conf_wd = -1, .dir_wd = -1 };
 605         struct vectors *vecs = trigger_data;
 606
 607         condlog(3, "uxsock: startup listener");
 608         polls = calloc(1, max_pfds * sizeof(*polls));
 609         if (!polls) {
 610                 condlog(0, "uxsock: failed to allocate poll fds");
 611                 exit_daemon();
 612                 return NULL;
 613         }
 614         notify_fd = inotify_init1(IN_NONBLOCK);
 615         if (notify_fd == -1) /* it's fine if notifications fail */
 616                 condlog(3, "failed to start up configuration notifications");
 617
 618         pthread_cleanup_push(wakeup_cleanup, &vecs->lock);
 619         idle_fd = eventfd(0, EFD_NONBLOCK|EFD_CLOEXEC);
 620         if (idle_fd == -1) {
 621                 condlog(1, "failed to create idle fd");
 622                 exit_daemon();
 623         } else
 624                 set_wakeup_fn(&vecs->lock, wakeup_listener);
 625
 626         sigfillset(&mask);
 627         sigdelset(&mask, SIGINT);
 628         sigdelset(&mask, SIGTERM);
 629         sigdelset(&mask, SIGHUP);
 630         sigdelset(&mask, SIGUSR1);
 631         while (1) {
 632                 struct client *c, *tmp;
 633                 int i, n_pfds, poll_count, num_clients;
 634                 struct timespec __timeout, *timeout;
 635
 636                 /* setup for a poll */
 637                 num_clients = 0;
 638                 list_for_each_entry(c, &clients, node) {
 639                         num_clients++;
 640                 }
 641                 if (num_clients + POLLFDS_BASE > max_pfds) {
 642                         struct pollfd *new;
 643                         int n_new = max_pfds + POLLFD_CHUNK;
 644
 645                         new = realloc(polls, n_new * sizeof(*polls));
 646                         if (new) {
 647                                 max_pfds = n_new;
 648                                 polls = new;
 649                         } else {
 650                                 condlog(1, "%s: realloc failure, %d clients not served",
 651                                         __func__,
 652                                         num_clients + POLLFDS_BASE - max_pfds);
 653                                 num_clients = max_pfds - POLLFDS_BASE;
 654                         }
 655                 }
 656                 if (num_clients < MAX_CLIENTS) {
 657                         polls[POLLFD_UX].fd = ux_sock;
 658                         polls[POLLFD_UX].events = POLLIN;
 659                 } else {
 660                         /*
 661                          * New clients can't connect, num_clients won't grow
 662                          * to MAX_CLIENTS or higher
 663                          */
 664                         condlog(1, "%s: max client connections reached, pausing polling",
 665                                 __func__);
 666                         polls[POLLFD_UX].fd = -1;
 667                 }
 668
 669                 reset_watch(notify_fd, &wds, &sequence_nr);
 670                 polls[POLLFD_NOTIFY].fd = notify_fd;
 671                 if (notify_fd == -1 || (wds.conf_wd == -1 && wds.dir_wd == -1))
 672                         polls[POLLFD_NOTIFY].events = 0;
 673                 else
 674                         polls[POLLFD_NOTIFY].events = POLLIN;
 675
 676                 polls[POLLFD_IDLE].fd = idle_fd;
 677                 if (need_vecs_lock())
 678                         polls[POLLFD_IDLE].events = POLLIN;
 679                 else
 680                         polls[POLLFD_IDLE].events = 0;
 681
 682                 /* setup the clients */
 683                 i = POLLFDS_BASE;
 684                 list_for_each_entry(c, &clients, node) {
 685                         switch(c->state) {
 686                         case CLT_RECV:
 687                                 polls[i].events = POLLIN;
 688                                 break;
 689                         case CLT_SEND:
 690                                 polls[i].events = POLLOUT;
 691                                 break;
 692                         default:
 693                                 /* don't poll for this client */
 694                                 continue;
 695                         }
 696                         polls[i].fd = c->fd;
 697                         i++;
 698                         if (i >= max_pfds)
 699                                 break;
 700                 }
 701                 n_pfds = i;
 702                 timeout = get_soonest_timeout(&__timeout);
 703
 704                 /* most of our life is spent in this call */
 705                 poll_count = ppoll(polls, n_pfds, timeout, &mask);
 706
 707                 handle_signals(false);
 708                 if (poll_count == -1) {
 709                         if (errno == EINTR) {
 710                                 handle_signals(true);
 711                                 continue;
 712                         }
 713
 714                         /* something went badly wrong! */
 715                         condlog(0, "uxsock: poll failed with %d", errno);
 716                         exit_daemon();
 717                         break;
 718                 }
 719
 720                 if (polls[POLLFD_IDLE].fd != -1 &&
 721                     polls[POLLFD_IDLE].revents & POLLIN)
 722                         drain_idle_fd(idle_fd);
 723
 724                 /* see if a client needs handling */
 725                 list_for_each_entry_safe(c, tmp, &clients, node) {
 726                         short revents = 0;
 727
 728                         for (i = POLLFDS_BASE; i < n_pfds; i++) {
 729                                 if (polls[i].fd == c->fd) {
 730                                         revents = polls[i].revents;
 731                                         break;
 732                                 }
 733                         }
 734
 735                         handle_client(c, trigger_data, revents);
 736
 737                         if (c->error == -ECONNRESET) {
 738                                 condlog(4, "cli[%d]: disconnected", c->fd);
 739                                 dead_client(c);
 740                                 if (i < n_pfds)
 741                                         polls[i].fd = -1;
 742                         }
 743                 }
 744                 /* see if we got a non-fatal signal */
 745                 handle_signals(true);
 746
 747                 /* see if we got a new client */
 748                 if (polls[POLLFD_UX].revents & POLLIN) {
 749                         new_client(ux_sock);
 750                 }
 751
 752                 /* handle inotify events on config files */
 753                 if (polls[POLLFD_NOTIFY].revents & POLLIN)
 754                         handle_inotify(notify_fd, &wds);
 755         }
 756
 757         pthread_cleanup_pop(1);
 758         return NULL;
 759 }