udevd.c

   1 /*
   2  * udevd.c - event listener and serializer
   3  *
   4  * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
   5  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
   6  *
   7  *
   8  *      This program is free software; you can redistribute it and/or modify it
   9  *      under the terms of the GNU General Public License as published by the
  10  *      Free Software Foundation version 2 of the License.
  11  *
  12  *      This program is distributed in the hope that it will be useful, but
  13  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  *      General Public License for more details.
  16  *
  17  *      You should have received a copy of the GNU General Public License along
  18  *      with this program; if not, write to the Free Software Foundation, Inc.,
  19  *      675 Mass Ave, Cambridge, MA 02139, USA.
  20  *
  21  */
  22
  23 #include <stddef.h>
  24 #include <signal.h>
  25 #include <unistd.h>
  26 #include <errno.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <ctype.h>
  31 #include <dirent.h>
  32 #include <fcntl.h>
  33 #include <syslog.h>
  34 #include <time.h>
  35 #include <sys/select.h>
  36 #include <sys/wait.h>
  37 #include <sys/types.h>
  38 #include <sys/socket.h>
  39 #include <sys/un.h>
  40 #include <sys/stat.h>
  41 #include <sys/ioctl.h>
  42 #include <linux/types.h>
  43 #include <linux/netlink.h>
  44
  45 #include "udev.h"
  46 #include "udev_rules.h"
  47 #include "udevd.h"
  48
  49 static struct udev_rules rules;
  50 static int udevd_sock;
  51 static int uevent_netlink_sock;
  52 static int inotify_fd;
  53 static pid_t sid;
  54
  55 static int signal_pipe[2] = {-1, -1};
  56 static volatile int sigchilds_waiting;
  57 static volatile int udev_exit;
  58 static volatile int reload_config;
  59 static int run_exec_q;
  60 static int stop_exec_q;
  61 static int max_childs;
  62 static int max_childs_running;
  63 static char udev_log[32];
  64
  65 static LIST_HEAD(exec_list);
  66 static LIST_HEAD(running_list);
  67
  68
  69 #ifdef USE_LOG
  70 void log_message(int priority, const char *format, ...)
  71 {
  72         va_list args;
  73
  74         if (priority > udev_log_priority)
  75                 return;
  76
  77         va_start(args, format);
  78         vsyslog(priority, format, args);
  79         va_end(args);
  80 }
  81 #endif
  82
  83 static void asmlinkage udev_event_sig_handler(int signum)
  84 {
  85         if (signum == SIGALRM)
  86                 exit(1);
  87 }
  88
  89 static int udev_event_process(struct uevent_msg *msg)
  90 {
  91         struct sigaction act;
  92         struct udevice *udev;
  93         int i;
  94         int retval;
  95
  96         /* set signal handlers */
  97         memset(&act, 0x00, sizeof(act));
  98         act.sa_handler = (void (*)(int)) udev_event_sig_handler;
  99         sigemptyset (&act.sa_mask);
 100         act.sa_flags = 0;
 101         sigaction(SIGALRM, &act, NULL);
 102
 103         /* trigger timeout to prevent hanging processes */
 104         alarm(UDEV_ALARM_TIMEOUT);
 105
 106         /* reconstruct event environment from message */
 107         for (i = 0; msg->envp[i]; i++)
 108                 putenv(msg->envp[i]);
 109
 110         udev = udev_device_init();
 111         if (udev == NULL)
 112                 return -1;
 113         strlcpy(udev->action, msg->action, sizeof(udev->action));
 114         sysfs_device_set_values(udev->dev, msg->devpath, msg->subsystem);
 115         udev->devt = msg->devt;
 116
 117         retval = udev_device_event(&rules, udev);
 118
 119         /* run programs collected by RUN-key*/
 120         if (retval == 0) {
 121                 struct name_entry *name_loop;
 122
 123                 list_for_each_entry(name_loop, &udev->run_list, node) {
 124                         if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
 125                                 pass_env_to_socket(&name_loop->name[strlen("socket:")], msg->devpath, msg->action);
 126                         else
 127                                 if (run_program(name_loop->name, udev->dev->subsystem, NULL, 0, NULL,
 128                                                 (udev_log_priority >= LOG_INFO)))
 129                                         retval = -1;
 130                 }
 131         }
 132
 133         udev_device_cleanup(udev);
 134         return retval;
 135 }
 136
 137 enum event_state {
 138         EVENT_QUEUED,
 139         EVENT_FINISHED,
 140         EVENT_FAILED,
 141 };
 142
 143 static void export_event_state(struct uevent_msg *msg, enum event_state state)
 144 {
 145         char filename[PATH_SIZE];
 146         char filename_failed[PATH_SIZE];
 147         char target[PATH_SIZE];
 148         size_t start, end, i;
 149         struct uevent_msg *loop_msg;
 150
 151         /* add location of queue files */
 152         strlcpy(filename, udev_root, sizeof(filename));
 153         strlcat(filename, "/", sizeof(filename));
 154         start = strlcat(filename, EVENT_QUEUE_DIR, sizeof(filename));
 155         end = strlcat(filename, msg->devpath, sizeof(filename));
 156         if (end > sizeof(filename))
 157                 end = sizeof(filename);
 158
 159         /* replace '/' to transform path into a filename */
 160         for (i = start+1; i < end; i++)
 161                 if (filename[i] == '/')
 162                         filename[i] = PATH_TO_NAME_CHAR;
 163
 164         /* add location of failed files */
 165         strlcpy(filename_failed, udev_root, sizeof(filename_failed));
 166         strlcat(filename_failed, "/", sizeof(filename_failed));
 167         start = strlcat(filename_failed, EVENT_FAILED_DIR, sizeof(filename_failed));
 168         end = strlcat(filename_failed, msg->devpath, sizeof(filename_failed));
 169         if (end > sizeof(filename_failed))
 170                 end = sizeof(filename_failed);
 171
 172         /* replace '/' to transform path into a filename */
 173         for (i = start+1; i < end; i++)
 174                 if (filename_failed[i] == '/')
 175                         filename_failed[i] = PATH_TO_NAME_CHAR;
 176
 177         switch (state) {
 178         case EVENT_QUEUED:
 179                 unlink(filename_failed);
 180                 delete_path(filename_failed);
 181
 182                 strlcpy(target, sysfs_path, sizeof(target));
 183                 strlcat(target, msg->devpath, sizeof(target));
 184                 create_path(filename);
 185                 symlink(target, filename);
 186                 return;
 187         case EVENT_FINISHED:
 188         case EVENT_FAILED:
 189                 unlink(filename_failed);
 190                 delete_path(filename_failed);
 191
 192                 /* don't remove, if events for the same path are still pending */
 193                 list_for_each_entry(loop_msg, &running_list, node)
 194                         if (loop_msg->devpath && strcmp(loop_msg->devpath, msg->devpath) == 0)
 195                                 return;
 196
 197                 /* move failed events to the failed directory */
 198                 if (state == EVENT_FAILED) {
 199                         create_path(filename_failed);
 200                         rename(filename, filename_failed);
 201                 } else {
 202                         unlink(filename);
 203                 }
 204
 205                 /* clean up the queue directory */
 206                 delete_path(filename);
 207
 208                 return;
 209         }
 210 }
 211
 212 static void msg_queue_delete(struct uevent_msg *msg)
 213 {
 214         list_del(&msg->node);
 215
 216         /* mark as failed, if add event returns non-zero */
 217         if (msg->exitstatus && strcmp(msg->action, "add") == 0)
 218                 export_event_state(msg, EVENT_FAILED);
 219         else
 220                 export_event_state(msg, EVENT_FINISHED);
 221
 222         free(msg);
 223 }
 224
 225 static void udev_event_run(struct uevent_msg *msg)
 226 {
 227         pid_t pid;
 228         int retval;
 229
 230         pid = fork();
 231         switch (pid) {
 232         case 0:
 233                 /* child */
 234                 close(uevent_netlink_sock);
 235                 close(udevd_sock);
 236                 if (inotify_fd > 0)
 237                         close(inotify_fd);
 238                 close(signal_pipe[READ_END]);
 239                 close(signal_pipe[WRITE_END]);
 240                 logging_close();
 241
 242                 logging_init("udevd-event");
 243                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 244                 retval = udev_event_process(msg);
 245                 info("seq %llu finished", msg->seqnum);
 246
 247                 logging_close();
 248                 if (retval)
 249                         exit(1);
 250                 exit(0);
 251         case -1:
 252                 err("fork of child failed: %s", strerror(errno));
 253                 msg_queue_delete(msg);
 254                 break;
 255         default:
 256                 /* get SIGCHLD in main loop */
 257                 info("seq %llu forked, pid [%d], '%s' '%s', %ld seconds old",
 258                      msg->seqnum, pid,  msg->action, msg->subsystem, time(NULL) - msg->queue_time);
 259                 msg->pid = pid;
 260         }
 261 }
 262
 263 static void msg_queue_insert(struct uevent_msg *msg)
 264 {
 265         msg->queue_time = time(NULL);
 266
 267         export_event_state(msg, EVENT_QUEUED);
 268
 269         /* run all events with a timeout set immediately */
 270         if (msg->timeout != 0) {
 271                 list_add_tail(&msg->node, &running_list);
 272                 udev_event_run(msg);
 273                 return;
 274         }
 275
 276         list_add_tail(&msg->node, &exec_list);
 277         run_exec_q = 1;
 278 }
 279
 280 /* runs event and removes event from run queue when finished */
 281 static int running_processes(void)
 282 {
 283         int f;
 284         static char buf[4096];
 285         int len;
 286         int running;
 287         const char *pos;
 288
 289         f = open("/proc/stat", O_RDONLY);
 290         if (f == -1)
 291                 return -1;
 292
 293         len = read(f, buf, sizeof(buf)-1);
 294         close(f);
 295
 296         if (len <= 0)
 297                 return -1;
 298         else
 299                 buf[len] = '\0';
 300
 301         pos = strstr(buf, "procs_running ");
 302         if (pos == NULL)
 303                 return -1;
 304
 305         if (sscanf(pos, "procs_running %u", &running) != 1)
 306                 return -1;
 307
 308         return running;
 309 }
 310
 311 /* return the number of process es in our session, count only until limit */
 312 static int running_processes_in_session(pid_t session, int limit)
 313 {
 314         DIR *dir;
 315         struct dirent *dent;
 316         int running = 0;
 317
 318         dir = opendir("/proc");
 319         if (!dir)
 320                 return -1;
 321
 322         /* read process info from /proc */
 323         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 324                 int f;
 325                 char procdir[64];
 326                 char line[256];
 327                 const char *pos;
 328                 char state;
 329                 pid_t ppid, pgrp, sess;
 330                 int len;
 331
 332                 if (!isdigit(dent->d_name[0]))
 333                         continue;
 334
 335                 snprintf(procdir, sizeof(procdir), "/proc/%s/stat", dent->d_name);
 336                 procdir[sizeof(procdir)-1] = '\0';
 337
 338                 f = open(procdir, O_RDONLY);
 339                 if (f == -1)
 340                         continue;
 341
 342                 len = read(f, line, sizeof(line)-1);
 343                 close(f);
 344
 345                 if (len <= 0)
 346                         continue;
 347                 else
 348                         line[len] = '\0';
 349
 350                 /* skip ugly program name */
 351                 pos = strrchr(line, ')') + 2;
 352                 if (pos == NULL)
 353                         continue;
 354
 355                 if (sscanf(pos, "%c %d %d %d ", &state, &ppid, &pgrp, &sess) != 4)
 356                         continue;
 357
 358                 /* count only processes in our session */
 359                 if (sess != session)
 360                         continue;
 361
 362                 /* count only running, no sleeping processes */
 363                 if (state != 'R')
 364                         continue;
 365
 366                 running++;
 367                 if (limit > 0 && running >= limit)
 368                         break;
 369         }
 370         closedir(dir);
 371
 372         return running;
 373 }
 374
 375 static int compare_devpath(const char *running, const char *waiting)
 376 {
 377         int i;
 378
 379         for (i = 0; i < PATH_SIZE; i++) {
 380                 /* identical device event found */
 381                 if (running[i] == '\0' && waiting[i] == '\0')
 382                         return 1;
 383
 384                 /* parent device event found */
 385                 if (running[i] == '\0' && waiting[i] == '/')
 386                         return 2;
 387
 388                 /* child device event found */
 389                 if (running[i] == '/' && waiting[i] == '\0')
 390                         return 3;
 391
 392                 /* no matching event */
 393                 if (running[i] != waiting[i])
 394                         break;
 395         }
 396
 397         return 0;
 398 }
 399
 400 /* returns still running task for the same device, its parent or its physical device */
 401 static int running_with_devpath(struct uevent_msg *msg, int limit)
 402 {
 403         struct uevent_msg *loop_msg;
 404         int childs_count = 0;
 405
 406         list_for_each_entry(loop_msg, &running_list, node) {
 407                 if (limit && childs_count++ > limit) {
 408                         dbg("%llu, maximum number (%i) of child reached", msg->seqnum, childs_count);
 409                         return 1;
 410                 }
 411
 412                 /* return running parent/child device event */
 413                 if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
 414                         dbg("%llu, child device event still running %llu (%s)",
 415                             msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
 416                         return 2;
 417                 }
 418
 419                 /* return running physical device event */
 420                 if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
 421                         if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
 422                                 dbg("%llu, physical device event still running %llu (%s)",
 423                                     msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
 424                                 return 3;
 425                         }
 426         }
 427
 428         return 0;
 429 }
 430
 431 /* exec queue management routine executes the events and serializes events in the same sequence */
 432 static void msg_queue_manager(void)
 433 {
 434         struct uevent_msg *loop_msg;
 435         struct uevent_msg *tmp_msg;
 436         int running;
 437
 438         if (list_empty(&exec_list))
 439                 return;
 440
 441         running = running_processes();
 442         dbg("%d processes runnning on system", running);
 443         if (running < 0)
 444                 running = max_childs_running;
 445
 446         list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) {
 447                 /* check running processes in our session and possibly throttle */
 448                 if (running >= max_childs_running) {
 449                         running = running_processes_in_session(sid, max_childs_running+10);
 450                         dbg("at least %d processes running in session", running);
 451                         if (running >= max_childs_running) {
 452                                 dbg("delay seq %llu, too many processes already running", loop_msg->seqnum);
 453                                 return;
 454                         }
 455                 }
 456
 457                 /* don't run two processes for the same devpath and wait for the parent*/
 458                 if (running_with_devpath(loop_msg, max_childs)) {
 459                         dbg("delay seq %llu (%s)", loop_msg->seqnum, loop_msg->devpath);
 460                         continue;
 461                 }
 462
 463                 /* move event to run list */
 464                 list_move_tail(&loop_msg->node, &running_list);
 465                 udev_event_run(loop_msg);
 466                 running++;
 467                 dbg("moved seq %llu to running list", loop_msg->seqnum);
 468         }
 469 }
 470
 471 static struct uevent_msg *get_msg_from_envbuf(const char *buf, int buf_size)
 472 {
 473         int bufpos;
 474         int i;
 475         struct uevent_msg *msg;
 476         int major = 0;
 477         int minor = 0;
 478
 479         msg = malloc(sizeof(struct uevent_msg) + buf_size);
 480         if (msg == NULL)
 481                 return NULL;
 482         memset(msg, 0x00, sizeof(struct uevent_msg) + buf_size);
 483
 484         /* copy environment buffer and reconstruct envp */
 485         memcpy(msg->envbuf, buf, buf_size);
 486         bufpos = 0;
 487         for (i = 0; (bufpos < buf_size) && (i < UEVENT_NUM_ENVP-2); i++) {
 488                 int keylen;
 489                 char *key;
 490
 491                 key = &msg->envbuf[bufpos];
 492                 keylen = strlen(key);
 493                 msg->envp[i] = key;
 494                 bufpos += keylen + 1;
 495                 dbg("add '%s' to msg.envp[%i]", msg->envp[i], i);
 496
 497                 /* remember some keys for further processing */
 498                 if (strncmp(key, "ACTION=", 7) == 0)
 499                         msg->action = &key[7];
 500                 else if (strncmp(key, "DEVPATH=", 8) == 0)
 501                         msg->devpath = &key[8];
 502                 else if (strncmp(key, "SUBSYSTEM=", 10) == 0)
 503                         msg->subsystem = &key[10];
 504                 else if (strncmp(key, "SEQNUM=", 7) == 0)
 505                         msg->seqnum = strtoull(&key[7], NULL, 10);
 506                 else if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
 507                         msg->physdevpath = &key[12];
 508                 else if (strncmp(key, "MAJOR=", 6) == 0)
 509                         major = strtoull(&key[6], NULL, 10);
 510                 else if (strncmp(key, "MINOR=", 6) == 0)
 511                         minor = strtoull(&key[6], NULL, 10);
 512                 else if (strncmp(key, "TIMEOUT=", 8) == 0)
 513                         msg->timeout = strtoull(&key[8], NULL, 10);
 514         }
 515         msg->devt = makedev(major, minor);
 516         msg->envp[i++] = "UDEVD_EVENT=1";
 517         msg->envp[i] = NULL;
 518
 519         if (!msg->devpath) {
 520                 info("DEVPATH missing, ignore message");
 521                 free(msg);
 522                 return NULL;
 523         }
 524
 525         return msg;
 526 }
 527
 528 /* receive the udevd message from userspace */
 529 static struct uevent_msg *get_udevd_msg(void)
 530 {
 531         static struct udevd_msg usend_msg;
 532         struct uevent_msg *msg;
 533         ssize_t size;
 534         struct msghdr smsg;
 535         struct cmsghdr *cmsg;
 536         struct iovec iov;
 537         struct ucred *cred;
 538         char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
 539         int envbuf_size;
 540         int *intval;
 541
 542         memset(&usend_msg, 0x00, sizeof(struct udevd_msg));
 543         iov.iov_base = &usend_msg;
 544         iov.iov_len = sizeof(struct udevd_msg);
 545
 546         memset(&smsg, 0x00, sizeof(struct msghdr));
 547         smsg.msg_iov = &iov;
 548         smsg.msg_iovlen = 1;
 549         smsg.msg_control = cred_msg;
 550         smsg.msg_controllen = sizeof(cred_msg);
 551
 552         size = recvmsg(udevd_sock, &smsg, 0);
 553         if (size <  0) {
 554                 if (errno != EINTR)
 555                         err("unable to receive user udevd message: %s", strerror(errno));
 556                 return NULL;
 557         }
 558         cmsg = CMSG_FIRSTHDR(&smsg);
 559         cred = (struct ucred *) CMSG_DATA(cmsg);
 560
 561         if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
 562                 err("no sender credentials received, message ignored");
 563                 return NULL;
 564         }
 565
 566         if (cred->uid != 0) {
 567                 err("sender uid=%i, message ignored", cred->uid);
 568                 return NULL;
 569         }
 570
 571         if (strncmp(usend_msg.magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
 572                 err("message magic '%s' doesn't match, ignore it", usend_msg.magic);
 573                 return NULL;
 574         }
 575
 576         switch (usend_msg.type) {
 577         case UDEVD_UEVENT_UDEVSEND:
 578         case UDEVD_UEVENT_INITSEND:
 579                 info("udevd event message received");
 580                 envbuf_size = size - offsetof(struct udevd_msg, envbuf);
 581                 dbg("envbuf_size=%i", envbuf_size);
 582                 msg = get_msg_from_envbuf(usend_msg.envbuf, envbuf_size);
 583                 if (msg == NULL)
 584                         return NULL;
 585                 msg->type = usend_msg.type;
 586                 return msg;
 587         case UDEVD_STOP_EXEC_QUEUE:
 588                 info("udevd message (STOP_EXEC_QUEUE) received");
 589                 stop_exec_q = 1;
 590                 break;
 591         case UDEVD_START_EXEC_QUEUE:
 592                 info("udevd message (START_EXEC_QUEUE) received");
 593                 stop_exec_q = 0;
 594                 msg_queue_manager();
 595                 break;
 596         case UDEVD_SET_LOG_LEVEL:
 597                 intval = (int *) usend_msg.envbuf;
 598                 info("udevd message (SET_LOG_PRIORITY) received, udev_log_priority=%i", *intval);
 599                 udev_log_priority = *intval;
 600                 sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
 601                 putenv(udev_log);
 602                 break;
 603         case UDEVD_SET_MAX_CHILDS:
 604                 intval = (int *) usend_msg.envbuf;
 605                 info("udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i", *intval);
 606                 max_childs = *intval;
 607                 break;
 608         case UDEVD_RELOAD_RULES:
 609                 info("udevd message (RELOAD_RULES) received");
 610                 reload_config = 1;
 611                 break;
 612         default:
 613                 dbg("unknown message type");
 614         }
 615         return NULL;
 616 }
 617
 618 /* receive the kernel user event message and do some sanity checks */
 619 static struct uevent_msg *get_netlink_msg(void)
 620 {
 621         struct uevent_msg *msg;
 622         int bufpos;
 623         ssize_t size;
 624         static char buffer[UEVENT_BUFFER_SIZE + 512];
 625         char *pos;
 626
 627         size = recv(uevent_netlink_sock, &buffer, sizeof(buffer), 0);
 628         if (size <  0) {
 629                 if (errno != EINTR)
 630                         err("unable to receive kernel netlink message: %s", strerror(errno));
 631                 return NULL;
 632         }
 633
 634         if ((size_t)size > sizeof(buffer)-1)
 635                 size = sizeof(buffer)-1;
 636         buffer[size] = '\0';
 637         dbg("uevent_size=%zi", size);
 638
 639         /* start of event payload */
 640         bufpos = strlen(buffer)+1;
 641         msg = get_msg_from_envbuf(&buffer[bufpos], size-bufpos);
 642         if (msg == NULL)
 643                 return NULL;
 644         msg->type = UDEVD_UEVENT_NETLINK;
 645
 646         /* validate message */
 647         pos = strchr(buffer, '@');
 648         if (pos == NULL) {
 649                 err("invalid uevent '%s'", buffer);
 650                 free(msg);
 651                 return NULL;
 652         }
 653         pos[0] = '\0';
 654
 655         if (msg->action == NULL) {
 656                 info("no ACTION in payload found, skip event '%s'", buffer);
 657                 free(msg);
 658                 return NULL;
 659         }
 660
 661         if (strcmp(msg->action, buffer) != 0) {
 662                 err("ACTION in payload does not match uevent, skip event '%s'", buffer);
 663                 free(msg);
 664                 return NULL;
 665         }
 666
 667         return msg;
 668 }
 669
 670 static void asmlinkage sig_handler(int signum)
 671 {
 672         switch (signum) {
 673                 case SIGINT:
 674                 case SIGTERM:
 675                         udev_exit = 1;
 676                         break;
 677                 case SIGCHLD:
 678                         /* set flag, then write to pipe if needed */
 679                         sigchilds_waiting = 1;
 680                         break;
 681                 case SIGHUP:
 682                         reload_config = 1;
 683                         break;
 684         }
 685
 686         /* write to pipe, which will wakeup select() in our mainloop */
 687         write(signal_pipe[WRITE_END], "", 1);
 688 }
 689
 690 static void udev_done(int pid, int exitstatus)
 691 {
 692         /* find msg associated with pid and delete it */
 693         struct uevent_msg *msg;
 694
 695         list_for_each_entry(msg, &running_list, node) {
 696                 if (msg->pid == pid) {
 697                         info("seq %llu, pid [%d] exit with %i, %ld seconds old", msg->seqnum, msg->pid,
 698                              exitstatus, time(NULL) - msg->queue_time);
 699                         msg->exitstatus = exitstatus;
 700                         msg_queue_delete(msg);
 701
 702                         /* there may be events waiting with the same devpath */
 703                         run_exec_q = 1;
 704                         return;
 705                 }
 706         }
 707 }
 708
 709 static void reap_sigchilds(void)
 710 {
 711         pid_t pid;
 712         int status;
 713
 714         while (1) {
 715                 pid = waitpid(-1, &status, WNOHANG);
 716                 if (pid <= 0)
 717                         break;
 718                 if (WIFEXITED(status))
 719                         status = WEXITSTATUS(status);
 720                 else if (WIFSIGNALED(status))
 721                         status = WTERMSIG(status) + 128;
 722                 else
 723                         status = 0;
 724                 udev_done(pid, status);
 725         }
 726 }
 727
 728 static int init_udevd_socket(void)
 729 {
 730         struct sockaddr_un saddr;
 731         const int buffersize = 16 * 1024 * 1024;
 732         socklen_t addrlen;
 733         const int feature_on = 1;
 734         int retval;
 735
 736         memset(&saddr, 0x00, sizeof(saddr));
 737         saddr.sun_family = AF_LOCAL;
 738         /* use abstract namespace for socket path */
 739         strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH);
 740         addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
 741
 742         udevd_sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
 743         if (udevd_sock == -1) {
 744                 err("error getting socket: %s", strerror(errno));
 745                 return -1;
 746         }
 747
 748         /* set receive buffersize */
 749         setsockopt(udevd_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
 750
 751         /* the bind takes care of ensuring only one copy running */
 752         retval = bind(udevd_sock, (struct sockaddr *) &saddr, addrlen);
 753         if (retval < 0) {
 754                 err("bind failed: %s", strerror(errno));
 755                 return -1;
 756         }
 757
 758         /* enable receiving of the sender credentials */
 759         setsockopt(udevd_sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
 760
 761         return 0;
 762 }
 763
 764 static int init_uevent_netlink_sock(void)
 765 {
 766         struct sockaddr_nl snl;
 767         const int buffersize = 16 * 1024 * 1024;
 768         int retval;
 769
 770         memset(&snl, 0x00, sizeof(struct sockaddr_nl));
 771         snl.nl_family = AF_NETLINK;
 772         snl.nl_pid = getpid();
 773         snl.nl_groups = 0xffffffff;
 774
 775         uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
 776         if (uevent_netlink_sock == -1) {
 777                 err("error getting socket: %s", strerror(errno));
 778                 return -1;
 779         }
 780
 781         /* set receive buffersize */
 782         setsockopt(uevent_netlink_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
 783
 784         retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl, sizeof(struct sockaddr_nl));
 785         if (retval < 0) {
 786                 err("bind failed: %s", strerror(errno));
 787                 close(uevent_netlink_sock);
 788                 uevent_netlink_sock = -1;
 789                 return -1;
 790         }
 791         return 0;
 792 }
 793
 794 int main(int argc, char *argv[], char *envp[])
 795 {
 796         int retval;
 797         int fd;
 798         struct sigaction act;
 799         fd_set readfds;
 800         const char *value;
 801         int daemonize = 0;
 802         int i;
 803         int rc = 0;
 804         int maxfd;
 805
 806         /* redirect std fd's, if the kernel forks us, we don't have them at all */
 807         fd = open("/dev/null", O_RDWR);
 808         if (fd >= 0) {
 809                 if (fd != STDIN_FILENO)
 810                         dup2(fd, STDIN_FILENO);
 811                 if (fd != STDOUT_FILENO)
 812                         dup2(fd, STDOUT_FILENO);
 813                 if (fd != STDERR_FILENO)
 814                         dup2(fd, STDERR_FILENO);
 815                 if (fd > STDERR_FILENO)
 816                         close(fd);
 817         }
 818
 819         logging_init("udevd");
 820         if (fd < 0)
 821                 err("fatal, could not open /dev/null: %s", strerror(errno));
 822
 823         udev_config_init();
 824         dbg("version %s", UDEV_VERSION);
 825
 826         if (getuid() != 0) {
 827                 err("need to be root, exit");
 828                 goto exit;
 829         }
 830
 831         /* parse commandline options */
 832         for (i = 1 ; i < argc; i++) {
 833                 char *arg = argv[i];
 834                 if (strcmp(arg, "--daemon") == 0 || strcmp(arg, "-d") == 0) {
 835                         info("will daemonize");
 836                         daemonize = 1;
 837                 }
 838                 if (strcmp(arg, "--stop-exec-queue") == 0) {
 839                         info("will not execute events until START_EXEC_QUEUE is received");
 840                         stop_exec_q = 1;
 841                 }
 842         }
 843
 844         /* init sockets to receive events */
 845         if (init_udevd_socket() < 0) {
 846                 if (errno == EADDRINUSE) {
 847                         err("another udevd running, exit");
 848                         rc = 1;
 849                 } else {
 850                         err("error initializing udevd socket: %s", strerror(errno));
 851                         rc = 2;
 852                 }
 853                 goto exit;
 854         }
 855
 856         if (init_uevent_netlink_sock() < 0) {
 857                 err("uevent socket not available");
 858                 rc = 3;
 859                 goto exit;
 860         }
 861
 862         /* parse the rules and keep it in memory */
 863         sysfs_init();
 864         udev_rules_init(&rules, 1);
 865
 866         if (daemonize) {
 867                 pid_t pid;
 868
 869                 pid = fork();
 870                 switch (pid) {
 871                 case 0:
 872                         dbg("daemonized fork running");
 873                         break;
 874                 case -1:
 875                         err("fork of daemon failed: %s", strerror(errno));
 876                         rc = 4;
 877                         goto exit;
 878                 default:
 879                         dbg("child [%u] running, parent exits", pid);
 880                         goto exit;
 881                 }
 882         }
 883
 884         /* set scheduling priority for the daemon */
 885         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 886
 887         chdir("/");
 888         umask(022);
 889
 890         /* become session leader */
 891         sid = setsid();
 892         dbg("our session is %d", sid);
 893
 894         /* OOM_DISABLE == -17 */
 895         fd = open("/proc/self/oom_adj", O_RDWR);
 896         if (fd < 0)
 897                 err("error disabling OOM: %s", strerror(errno));
 898         else {
 899                 write(fd, "-17", 3);
 900                 close(fd);
 901         }
 902
 903         /* setup signal handler pipe */
 904         retval = pipe(signal_pipe);
 905         if (retval < 0) {
 906                 err("error getting pipes: %s", strerror(errno));
 907                 goto exit;
 908         }
 909         retval = fcntl(signal_pipe[READ_END], F_SETFL, O_NONBLOCK);
 910         if (retval < 0) {
 911                 err("error fcntl on read pipe: %s", strerror(errno));
 912                 goto exit;
 913         }
 914         retval = fcntl(signal_pipe[WRITE_END], F_SETFL, O_NONBLOCK);
 915         if (retval < 0) {
 916                 err("error fcntl on write pipe: %s", strerror(errno));
 917                 goto exit;
 918         }
 919
 920         /* set signal handlers */
 921         memset(&act, 0x00, sizeof(struct sigaction));
 922         act.sa_handler = (void (*)(int)) sig_handler;
 923         sigemptyset(&act.sa_mask);
 924         act.sa_flags = SA_RESTART;
 925         sigaction(SIGINT, &act, NULL);
 926         sigaction(SIGTERM, &act, NULL);
 927         sigaction(SIGCHLD, &act, NULL);
 928         sigaction(SIGHUP, &act, NULL);
 929
 930         /* watch rules directory */
 931         inotify_fd = inotify_init();
 932         if (inotify_fd > 0)
 933                 inotify_add_watch(inotify_fd, udev_rules_filename, IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 934
 935         /* maximum limit of forked childs */
 936         value = getenv("UDEVD_MAX_CHILDS");
 937         if (value)
 938                 max_childs = strtoul(value, NULL, 10);
 939         else
 940                 max_childs = UDEVD_MAX_CHILDS;
 941         info("initialize max_childs to %u", max_childs);
 942
 943         /* start to throttle forking if maximum number of _running_ childs is reached */
 944         value = getenv("UDEVD_MAX_CHILDS_RUNNING");
 945         if (value)
 946                 max_childs_running = strtoull(value, NULL, 10);
 947         else
 948                 max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
 949         info("initialize max_childs_running to %u", max_childs_running);
 950
 951         /* clear environment for forked event processes */
 952         clearenv();
 953
 954         /* export log_priority , as called programs may want to follow that setting */
 955         sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
 956         putenv(udev_log);
 957
 958         maxfd = udevd_sock;
 959         maxfd = UDEV_MAX(maxfd, uevent_netlink_sock);
 960         maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
 961         maxfd = UDEV_MAX(maxfd, inotify_fd);
 962
 963         while (!udev_exit) {
 964                 struct uevent_msg *msg;
 965                 int fdcount;
 966
 967                 FD_ZERO(&readfds);
 968                 FD_SET(signal_pipe[READ_END], &readfds);
 969                 FD_SET(udevd_sock, &readfds);
 970                 FD_SET(uevent_netlink_sock, &readfds);
 971                 if (inotify_fd > 0)
 972                         FD_SET(inotify_fd, &readfds);
 973
 974                 fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
 975                 if (fdcount < 0) {
 976                         if (errno != EINTR)
 977                                 err("error in select: %s", strerror(errno));
 978                         continue;
 979                 }
 980
 981                 /* get user socket message */
 982                 if (FD_ISSET(udevd_sock, &readfds)) {
 983                         msg = get_udevd_msg();
 984                         if (msg)
 985                                 msg_queue_insert(msg);
 986                 }
 987
 988                 /* get kernel netlink message */
 989                 if (FD_ISSET(uevent_netlink_sock, &readfds)) {
 990                         msg = get_netlink_msg();
 991                         if (msg)
 992                                 msg_queue_insert(msg);
 993                 }
 994
 995                 /* received a signal, clear our notification pipe */
 996                 if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
 997                         char buf[256];
 998
 999                         read(signal_pipe[READ_END], &buf, sizeof(buf));
1000                 }
1001
1002                 /* rules directory inotify watch */
1003                 if ((inotify_fd > 0) && FD_ISSET(inotify_fd, &readfds)) {
1004                         int nbytes;
1005
1006                         /* discard all possible events, we can just reload the config */
1007                         if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes) {
1008                                 char *buf;
1009
1010                                 reload_config = 1;
1011                                 buf = malloc(nbytes);
1012                                 if (!buf) {
1013                                         err("error getting buffer for inotify, disable watching");
1014                                         close(inotify_fd);
1015                                         inotify_fd = -1;
1016                                 }
1017                                 read(inotify_fd, buf, nbytes);
1018                                 free(buf);
1019                         }
1020                 }
1021
1022                 /* rules changed, set by inotify or a signal*/
1023                 if (reload_config) {
1024                         reload_config = 0;
1025                         udev_rules_cleanup(&rules);
1026                         udev_rules_init(&rules, 1);
1027                 }
1028
1029                 /* forked child has returned */
1030                 if (sigchilds_waiting) {
1031                         sigchilds_waiting = 0;
1032                         reap_sigchilds();
1033                 }
1034
1035                 if (run_exec_q) {
1036                         run_exec_q = 0;
1037                         if (!stop_exec_q)
1038                                 msg_queue_manager();
1039                 }
1040         }
1041
1042 exit:
1043         udev_rules_cleanup(&rules);
1044         sysfs_cleanup();
1045
1046         if (signal_pipe[READ_END] > 0)
1047                 close(signal_pipe[READ_END]);
1048         if (signal_pipe[WRITE_END] > 0)
1049                 close(signal_pipe[WRITE_END]);
1050
1051         if (udevd_sock > 0)
1052                 close(udevd_sock);
1053         if (inotify_fd > 0)
1054                 close(inotify_fd);
1055         if (uevent_netlink_sock > 0)
1056                 close(uevent_netlink_sock);
1057
1058         logging_close();
1059
1060         return rc;
1061 }