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 "list.h"
  46 #include "udev_libc_wrapper.h"
  47 #include "udev.h"
  48 #include "udev_version.h"
  49 #include "udev_rules.h"
  50 #include "udev_utils.h"
  51 #include "udevd.h"
  52 #include "logging.h"
  53
  54 struct udev_rules rules;
  55 static int udevd_sock;
  56 static int uevent_netlink_sock;
  57 static int inotify_fd;
  58 static pid_t sid;
  59
  60 static int signal_pipe[2] = {-1, -1};
  61 static volatile int sigchilds_waiting;
  62 static volatile int udev_exit;
  63 static volatile int reload_config;
  64 static int run_exec_q;
  65 static int stop_exec_q;
  66 static int max_childs;
  67 static int max_childs_running;
  68 static char udev_log[32];
  69
  70 static LIST_HEAD(exec_list);
  71 static LIST_HEAD(running_list);
  72
  73
  74 #ifdef USE_LOG
  75 void log_message(int priority, const char *format, ...)
  76 {
  77         va_list args;
  78
  79         if (priority > udev_log_priority)
  80                 return;
  81
  82         va_start(args, format);
  83         vsyslog(priority, format, args);
  84         va_end(args);
  85 }
  86 #endif
  87
  88 static void asmlinkage udev_event_sig_handler(int signum)
  89 {
  90         if (signum == SIGALRM)
  91                 exit(1);
  92 }
  93
  94 static int udev_event_process(struct uevent_msg *msg)
  95 {
  96         struct sigaction act;
  97         struct udevice udev;
  98         struct name_entry *name_loop;
  99         int i;
 100         int retval;
 101
 102         /* set signal handlers */
 103         memset(&act, 0x00, sizeof(act));
 104         act.sa_handler = (void (*)(int)) udev_event_sig_handler;
 105         sigemptyset (&act.sa_mask);
 106         act.sa_flags = 0;
 107         sigaction(SIGALRM, &act, NULL);
 108
 109         /* trigger timeout to prevent hanging processes */
 110         alarm(UDEV_ALARM_TIMEOUT);
 111
 112         /* reconstruct env from message */
 113         for (i = 0; msg->envp[i]; i++)
 114                 putenv(msg->envp[i]);
 115
 116         udev_init_device(&udev, msg->devpath, msg->subsystem, msg->action);
 117         retval = udev_process_event(&rules, &udev);
 118
 119         /* run programs collected by RUN-key*/
 120         if (!retval) {
 121                 list_for_each_entry(name_loop, &udev.run_list, node) {
 122                         if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
 123                                 pass_env_to_socket(&name_loop->name[strlen("socket:")], msg->devpath, msg->action);
 124                         else
 125                                 if (run_program(name_loop->name, udev.subsystem, NULL, 0, NULL,
 126                                                 (udev_log_priority >= LOG_INFO)))
 127                                         retval = -1;
 128                 }
 129         }
 130
 131         udev_cleanup_device(&udev);
 132
 133         return retval;
 134 }
 135
 136 enum event_state {
 137         EVENT_QUEUED,
 138         EVENT_FINISHED,
 139         EVENT_FAILED,
 140 };
 141
 142 static void export_event_state(struct uevent_msg *msg, enum event_state state)
 143 {
 144         char filename[PATH_SIZE];
 145         char filename_failed[PATH_SIZE];
 146         char target[PATH_SIZE];
 147         size_t start, end, i;
 148         struct uevent_msg *loop_msg;
 149
 150         /* add location of queue files */
 151         strlcpy(filename, udev_root, sizeof(filename));
 152         strlcat(filename, "/", sizeof(filename));
 153         start = strlcat(filename, EVENT_QUEUE_DIR, sizeof(filename));
 154         end = strlcat(filename, msg->devpath, sizeof(filename));
 155         if (end > sizeof(filename))
 156                 end = sizeof(filename);
 157
 158         /* replace '/' to transform path into a filename */
 159         for (i = start+1; i < end; i++)
 160                 if (filename[i] == '/')
 161                         filename[i] = PATH_TO_NAME_CHAR;
 162
 163         /* add location of failed files */
 164         strlcpy(filename_failed, udev_root, sizeof(filename_failed));
 165         strlcat(filename_failed, "/", sizeof(filename_failed));
 166         start = strlcat(filename_failed, EVENT_FAILED_DIR, sizeof(filename_failed));
 167         end = strlcat(filename_failed, msg->devpath, sizeof(filename_failed));
 168         if (end > sizeof(filename_failed))
 169                 end = sizeof(filename_failed);
 170
 171         /* replace '/' to transform path into a filename */
 172         for (i = start+1; i < end; i++)
 173                 if (filename_failed[i] == '/')
 174                         filename_failed[i] = PATH_TO_NAME_CHAR;
 175
 176         switch (state) {
 177         case EVENT_QUEUED:
 178                 unlink(filename_failed);
 179                 delete_path(filename_failed);
 180
 181                 strlcpy(target, sysfs_path, sizeof(target));
 182                 strlcat(target, msg->devpath, sizeof(target));
 183                 create_path(filename);
 184                 symlink(target, filename);
 185                 return;
 186         case EVENT_FINISHED:
 187         case EVENT_FAILED:
 188                 unlink(filename_failed);
 189                 delete_path(filename_failed);
 190
 191                 /* don't remove, if events for the same path are still pending */
 192                 list_for_each_entry(loop_msg, &running_list, node)
 193                         if (loop_msg->devpath && strcmp(loop_msg->devpath, msg->devpath) == 0)
 194                                 return;
 195
 196                 /* move failed events to the failed directory */
 197                 if (state == EVENT_FAILED) {
 198                         create_path(filename_failed);
 199                         rename(filename, filename_failed);
 200                 } else {
 201                         unlink(filename);
 202                 }
 203
 204                 /* clean up the queue directory */
 205                 delete_path(filename);
 206
 207                 return;
 208         }
 209 }
 210
 211 static void msg_queue_delete(struct uevent_msg *msg)
 212 {
 213         list_del(&msg->node);
 214
 215         /* mark as failed, if add event returns non-zero */
 216         if (msg->exitstatus && strcmp(msg->action, "add") == 0)
 217                 export_event_state(msg, EVENT_FAILED);
 218         else
 219                 export_event_state(msg, EVENT_FINISHED);
 220
 221         free(msg);
 222 }
 223
 224 static void udev_event_run(struct uevent_msg *msg)
 225 {
 226         pid_t pid;
 227         int retval;
 228
 229         pid = fork();
 230         switch (pid) {
 231         case 0:
 232                 /* child */
 233                 close(uevent_netlink_sock);
 234                 close(udevd_sock);
 235                 if (inotify_fd > 0)
 236                         close(inotify_fd);
 237                 close(signal_pipe[READ_END]);
 238                 close(signal_pipe[WRITE_END]);
 239                 logging_close();
 240
 241                 logging_init("udevd-event");
 242                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 243                 retval = udev_event_process(msg);
 244                 info("seq %llu finished", msg->seqnum);
 245
 246                 logging_close();
 247                 if (retval)
 248                         exit(1);
 249                 exit(0);
 250         case -1:
 251                 err("fork of child failed: %s", strerror(errno));
 252                 msg_queue_delete(msg);
 253                 break;
 254         default:
 255                 /* get SIGCHLD in main loop */
 256                 info("seq %llu forked, pid [%d], '%s' '%s', %ld seconds old",
 257                      msg->seqnum, pid,  msg->action, msg->subsystem, time(NULL) - msg->queue_time);
 258                 msg->pid = pid;
 259         }
 260 }
 261
 262 static void msg_queue_insert(struct uevent_msg *msg)
 263 {
 264         msg->queue_time = time(NULL);
 265
 266         export_event_state(msg, EVENT_QUEUED);
 267
 268         /* run all events with a timeout set immediately */
 269         if (msg->timeout != 0) {
 270                 list_add_tail(&msg->node, &running_list);
 271                 udev_event_run(msg);
 272                 return;
 273         }
 274
 275         list_add_tail(&msg->node, &exec_list);
 276         run_exec_q = 1;
 277 }
 278
 279 /* runs event and removes event from run queue when finished */
 280 static int running_processes(void)
 281 {
 282         int f;
 283         static char buf[4096];
 284         int len;
 285         int running;
 286         const char *pos;
 287
 288         f = open("/proc/stat", O_RDONLY);
 289         if (f == -1)
 290                 return -1;
 291
 292         len = read(f, buf, sizeof(buf)-1);
 293         close(f);
 294
 295         if (len <= 0)
 296                 return -1;
 297         else
 298                 buf[len] = '\0';
 299
 300         pos = strstr(buf, "procs_running ");
 301         if (pos == NULL)
 302                 return -1;
 303
 304         if (sscanf(pos, "procs_running %u", &running) != 1)
 305                 return -1;
 306
 307         return running;
 308 }
 309
 310 /* return the number of process es in our session, count only until limit */
 311 static int running_processes_in_session(pid_t session, int limit)
 312 {
 313         DIR *dir;
 314         struct dirent *dent;
 315         int running = 0;
 316
 317         dir = opendir("/proc");
 318         if (!dir)
 319                 return -1;
 320
 321         /* read process info from /proc */
 322         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 323                 int f;
 324                 char procdir[64];
 325                 char line[256];
 326                 const char *pos;
 327                 char state;
 328                 pid_t ppid, pgrp, sess;
 329                 int len;
 330
 331                 if (!isdigit(dent->d_name[0]))
 332                         continue;
 333
 334                 snprintf(procdir, sizeof(procdir), "/proc/%s/stat", dent->d_name);
 335                 procdir[sizeof(procdir)-1] = '\0';
 336
 337                 f = open(procdir, O_RDONLY);
 338                 if (f == -1)
 339                         continue;
 340
 341                 len = read(f, line, sizeof(line)-1);
 342                 close(f);
 343
 344                 if (len <= 0)
 345                         continue;
 346                 else
 347                         line[len] = '\0';
 348
 349                 /* skip ugly program name */
 350                 pos = strrchr(line, ')') + 2;
 351                 if (pos == NULL)
 352                         continue;
 353
 354                 if (sscanf(pos, "%c %d %d %d ", &state, &ppid, &pgrp, &sess) != 4)
 355                         continue;
 356
 357                 /* count only processes in our session */
 358                 if (sess != session)
 359                         continue;
 360
 361                 /* count only running, no sleeping processes */
 362                 if (state != 'R')
 363                         continue;
 364
 365                 running++;
 366                 if (limit > 0 && running >= limit)
 367                         break;
 368         }
 369         closedir(dir);
 370
 371         return running;
 372 }
 373
 374 static int compare_devpath(const char *running, const char *waiting)
 375 {
 376         int i;
 377
 378         for (i = 0; i < PATH_SIZE; i++) {
 379                 /* identical device event found */
 380                 if (running[i] == '\0' && waiting[i] == '\0')
 381                         return 1;
 382
 383                 /* parent device event found */
 384                 if (running[i] == '\0' && waiting[i] == '/')
 385                         return 2;
 386
 387                 /* child device event found */
 388                 if (running[i] == '/' && waiting[i] == '\0')
 389                         return 3;
 390
 391                 /* no matching event */
 392                 if (running[i] != waiting[i])
 393                         break;
 394         }
 395
 396         return 0;
 397 }
 398
 399 /* returns still running task for the same device, its parent or its physical device */
 400 static int running_with_devpath(struct uevent_msg *msg, int limit)
 401 {
 402         struct uevent_msg *loop_msg;
 403         int childs_count = 0;
 404
 405         list_for_each_entry(loop_msg, &running_list, node) {
 406                 if (limit && childs_count++ > limit) {
 407                         dbg("%llu, maximum number (%i) of child reached", msg->seqnum, childs_count);
 408                         return 1;
 409                 }
 410
 411                 /* return running parent/child device event */
 412                 if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
 413                         dbg("%llu, child device event still running %llu (%s)",
 414                             msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
 415                         return 2;
 416                 }
 417
 418                 /* return running physical device event */
 419                 if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
 420                         if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
 421                                 dbg("%llu, physical device event still running %llu (%s)",
 422                                     msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
 423                                 return 3;
 424                         }
 425         }
 426
 427         return 0;
 428 }
 429
 430 /* exec queue management routine executes the events and serializes events in the same sequence */
 431 static void msg_queue_manager(void)
 432 {
 433         struct uevent_msg *loop_msg;
 434         struct uevent_msg *tmp_msg;
 435         int running;
 436
 437         if (list_empty(&exec_list))
 438                 return;
 439
 440         running = running_processes();
 441         dbg("%d processes runnning on system", running);
 442         if (running < 0)
 443                 running = max_childs_running;
 444
 445         list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) {
 446                 /* check running processes in our session and possibly throttle */
 447                 if (running >= max_childs_running) {
 448                         running = running_processes_in_session(sid, max_childs_running+10);
 449                         dbg("at least %d processes running in session", running);
 450                         if (running >= max_childs_running) {
 451                                 dbg("delay seq %llu, too many processes already running", loop_msg->seqnum);
 452                                 return;
 453                         }
 454                 }
 455
 456                 /* don't run two processes for the same devpath and wait for the parent*/
 457                 if (running_with_devpath(loop_msg, max_childs)) {
 458                         dbg("delay seq %llu (%s)", loop_msg->seqnum, loop_msg->devpath);
 459                         continue;
 460                 }
 461
 462                 /* move event to run list */
 463                 list_move_tail(&loop_msg->node, &running_list);
 464                 udev_event_run(loop_msg);
 465                 running++;
 466                 dbg("moved seq %llu to running list", loop_msg->seqnum);
 467         }
 468 }
 469
 470 static struct uevent_msg *get_msg_from_envbuf(const char *buf, int buf_size)
 471 {
 472         int bufpos;
 473         int i;
 474         struct uevent_msg *msg;
 475         int major = 0;
 476         int minor = 0;
 477
 478         msg = malloc(sizeof(struct uevent_msg) + buf_size);
 479         if (msg == NULL)
 480                 return NULL;
 481         memset(msg, 0x00, sizeof(struct uevent_msg) + buf_size);
 482
 483         /* copy environment buffer and reconstruct envp */
 484         memcpy(msg->envbuf, buf, buf_size);
 485         bufpos = 0;
 486         for (i = 0; (bufpos < buf_size) && (i < UEVENT_NUM_ENVP-2); i++) {
 487                 int keylen;
 488                 char *key;
 489
 490                 key = &msg->envbuf[bufpos];
 491                 keylen = strlen(key);
 492                 msg->envp[i] = key;
 493                 bufpos += keylen + 1;
 494                 dbg("add '%s' to msg.envp[%i]", msg->envp[i], i);
 495
 496                 /* remember some keys for further processing */
 497                 if (strncmp(key, "ACTION=", 7) == 0)
 498                         msg->action = &key[7];
 499                 else if (strncmp(key, "DEVPATH=", 8) == 0)
 500                         msg->devpath = &key[8];
 501                 else if (strncmp(key, "SUBSYSTEM=", 10) == 0)
 502                         msg->subsystem = &key[10];
 503                 else if (strncmp(key, "SEQNUM=", 7) == 0)
 504                         msg->seqnum = strtoull(&key[7], NULL, 10);
 505                 else if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
 506                         msg->physdevpath = &key[12];
 507                 else if (strncmp(key, "MAJOR=", 6) == 0)
 508                         major = strtoull(&key[6], NULL, 10);
 509                 else if (strncmp(key, "MINOR=", 6) == 0)
 510                         minor = strtoull(&key[6], NULL, 10);
 511                 else if (strncmp(key, "TIMEOUT=", 8) == 0)
 512                         msg->timeout = strtoull(&key[8], NULL, 10);
 513         }
 514         msg->devt = makedev(major, minor);
 515         msg->envp[i++] = "UDEVD_EVENT=1";
 516         msg->envp[i] = NULL;
 517
 518         if (!msg->devpath) {
 519                 info("DEVPATH missing, ignore message");
 520                 free(msg);
 521                 return NULL;
 522         }
 523
 524         return msg;
 525 }
 526
 527 /* receive the udevd message from userspace */
 528 static struct uevent_msg *get_udevd_msg(void)
 529 {
 530         static struct udevd_msg usend_msg;
 531         struct uevent_msg *msg;
 532         ssize_t size;
 533         struct msghdr smsg;
 534         struct cmsghdr *cmsg;
 535         struct iovec iov;
 536         struct ucred *cred;
 537         char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
 538         int envbuf_size;
 539         int *intval;
 540
 541         memset(&usend_msg, 0x00, sizeof(struct udevd_msg));
 542         iov.iov_base = &usend_msg;
 543         iov.iov_len = sizeof(struct udevd_msg);
 544
 545         memset(&smsg, 0x00, sizeof(struct msghdr));
 546         smsg.msg_iov = &iov;
 547         smsg.msg_iovlen = 1;
 548         smsg.msg_control = cred_msg;
 549         smsg.msg_controllen = sizeof(cred_msg);
 550
 551         size = recvmsg(udevd_sock, &smsg, 0);
 552         if (size <  0) {
 553                 if (errno != EINTR)
 554                         err("unable to receive udevd message: %s", strerror(errno));
 555                 return NULL;
 556         }
 557         cmsg = CMSG_FIRSTHDR(&smsg);
 558         cred = (struct ucred *) CMSG_DATA(cmsg);
 559
 560         if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
 561                 err("no sender credentials received, message ignored");
 562                 return NULL;
 563         }
 564
 565         if (cred->uid != 0) {
 566                 err("sender uid=%i, message ignored", cred->uid);
 567                 return NULL;
 568         }
 569
 570         if (strncmp(usend_msg.magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
 571                 err("message magic '%s' doesn't match, ignore it", usend_msg.magic);
 572                 return NULL;
 573         }
 574
 575         switch (usend_msg.type) {
 576         case UDEVD_UEVENT_UDEVSEND:
 577         case UDEVD_UEVENT_INITSEND:
 578                 info("udevd event message received");
 579                 envbuf_size = size - offsetof(struct udevd_msg, envbuf);
 580                 dbg("envbuf_size=%i", envbuf_size);
 581                 msg = get_msg_from_envbuf(usend_msg.envbuf, envbuf_size);
 582                 if (msg == NULL)
 583                         return NULL;
 584                 msg->type = usend_msg.type;
 585                 return msg;
 586         case UDEVD_STOP_EXEC_QUEUE:
 587                 info("udevd message (STOP_EXEC_QUEUE) received");
 588                 stop_exec_q = 1;
 589                 break;
 590         case UDEVD_START_EXEC_QUEUE:
 591                 info("udevd message (START_EXEC_QUEUE) received");
 592                 stop_exec_q = 0;
 593                 msg_queue_manager();
 594                 break;
 595         case UDEVD_SET_LOG_LEVEL:
 596                 intval = (int *) usend_msg.envbuf;
 597                 info("udevd message (SET_LOG_PRIORITY) received, udev_log_priority=%i", *intval);
 598                 udev_log_priority = *intval;
 599                 sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
 600                 putenv(udev_log);
 601                 break;
 602         case UDEVD_SET_MAX_CHILDS:
 603                 intval = (int *) usend_msg.envbuf;
 604                 info("udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i", *intval);
 605                 max_childs = *intval;
 606                 break;
 607         case UDEVD_RELOAD_RULES:
 608                 info("udevd message (RELOAD_RULES) received");
 609                 reload_config = 1;
 610                 break;
 611         default:
 612                 dbg("unknown message type");
 613         }
 614         return NULL;
 615 }
 616
 617 /* receive the kernel user event message and do some sanity checks */
 618 static struct uevent_msg *get_netlink_msg(void)
 619 {
 620         struct uevent_msg *msg;
 621         int bufpos;
 622         ssize_t size;
 623         static char buffer[UEVENT_BUFFER_SIZE + 512];
 624         char *pos;
 625
 626         size = recv(uevent_netlink_sock, &buffer, sizeof(buffer), 0);
 627         if (size <  0) {
 628                 if (errno != EINTR)
 629                         err("unable to receive udevd message: %s", strerror(errno));
 630                 return NULL;
 631         }
 632
 633         if ((size_t)size > sizeof(buffer)-1)
 634                 size = sizeof(buffer)-1;
 635         buffer[size] = '\0';
 636         dbg("uevent_size=%zi", size);
 637
 638         /* start of event payload */
 639         bufpos = strlen(buffer)+1;
 640         msg = get_msg_from_envbuf(&buffer[bufpos], size-bufpos);
 641         if (msg == NULL)
 642                 return NULL;
 643         msg->type = UDEVD_UEVENT_NETLINK;
 644
 645         /* validate message */
 646         pos = strchr(buffer, '@');
 647         if (pos == NULL) {
 648                 err("invalid uevent '%s'", buffer);
 649                 free(msg);
 650                 return NULL;
 651         }
 652         pos[0] = '\0';
 653
 654         if (msg->action == NULL) {
 655                 info("no ACTION in payload found, skip event '%s'", buffer);
 656                 free(msg);
 657                 return NULL;
 658         }
 659
 660         if (strcmp(msg->action, buffer) != 0) {
 661                 err("ACTION in payload does not match uevent, skip event '%s'", buffer);
 662                 free(msg);
 663                 return NULL;
 664         }
 665
 666         return msg;
 667 }
 668
 669 static void asmlinkage sig_handler(int signum)
 670 {
 671         switch (signum) {
 672                 case SIGINT:
 673                 case SIGTERM:
 674                         udev_exit = 1;
 675                         break;
 676                 case SIGCHLD:
 677                         /* set flag, then write to pipe if needed */
 678                         sigchilds_waiting = 1;
 679                         break;
 680                 case SIGHUP:
 681                         reload_config = 1;
 682                         break;
 683         }
 684
 685         /* write to pipe, which will wakeup select() in our mainloop */
 686         write(signal_pipe[WRITE_END], "", 1);
 687 }
 688
 689 static void udev_done(int pid, int exitstatus)
 690 {
 691         /* find msg associated with pid and delete it */
 692         struct uevent_msg *msg;
 693
 694         list_for_each_entry(msg, &running_list, node) {
 695                 if (msg->pid == pid) {
 696                         info("seq %llu, pid [%d] exit with %i, %ld seconds old", msg->seqnum, msg->pid,
 697                              exitstatus, time(NULL) - msg->queue_time);
 698                         msg->exitstatus = exitstatus;
 699                         msg_queue_delete(msg);
 700
 701                         /* there may be events waiting with the same devpath */
 702                         run_exec_q = 1;
 703                         return;
 704                 }
 705         }
 706 }
 707
 708 static void reap_sigchilds(void)
 709 {
 710         pid_t pid;
 711         int status;
 712
 713         while (1) {
 714                 pid = waitpid(-1, &status, WNOHANG);
 715                 if (pid <= 0)
 716                         break;
 717                 if (WIFEXITED(status))
 718                         status = WEXITSTATUS(status);
 719                 else if (WIFSIGNALED(status))
 720                         status = WTERMSIG(status) + 128;
 721                 else
 722                         status = 0;
 723                 udev_done(pid, status);
 724         }
 725 }
 726
 727 static int init_udevd_socket(void)
 728 {
 729         struct sockaddr_un saddr;
 730         const int buffersize = 16 * 1024 * 1024;
 731         socklen_t addrlen;
 732         const int feature_on = 1;
 733         int retval;
 734
 735         memset(&saddr, 0x00, sizeof(saddr));
 736         saddr.sun_family = AF_LOCAL;
 737         /* use abstract namespace for socket path */
 738         strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH);
 739         addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
 740
 741         udevd_sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
 742         if (udevd_sock == -1) {
 743                 err("error getting socket: %s", strerror(errno));
 744                 return -1;
 745         }
 746
 747         /* set receive buffersize */
 748         setsockopt(udevd_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
 749
 750         /* the bind takes care of ensuring only one copy running */
 751         retval = bind(udevd_sock, (struct sockaddr *) &saddr, addrlen);
 752         if (retval < 0) {
 753                 err("bind failed: %s", strerror(errno));
 754                 return -1;
 755         }
 756
 757         /* enable receiving of the sender credentials */
 758         setsockopt(udevd_sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
 759
 760         return 0;
 761 }
 762
 763 static int init_uevent_netlink_sock(void)
 764 {
 765         struct sockaddr_nl snl;
 766         const int buffersize = 16 * 1024 * 1024;
 767         int retval;
 768
 769         memset(&snl, 0x00, sizeof(struct sockaddr_nl));
 770         snl.nl_family = AF_NETLINK;
 771         snl.nl_pid = getpid();
 772         snl.nl_groups = 0xffffffff;
 773
 774         uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
 775         if (uevent_netlink_sock == -1) {
 776                 err("error getting socket: %s", strerror(errno));
 777                 return -1;
 778         }
 779
 780         /* set receive buffersize */
 781         setsockopt(uevent_netlink_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
 782
 783         retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl, sizeof(struct sockaddr_nl));
 784         if (retval < 0) {
 785                 err("bind failed: %s", strerror(errno));
 786                 close(uevent_netlink_sock);
 787                 uevent_netlink_sock = -1;
 788                 return -1;
 789         }
 790         return 0;
 791 }
 792
 793 int main(int argc, char *argv[], char *envp[])
 794 {
 795         int retval;
 796         int fd;
 797         struct sigaction act;
 798         fd_set readfds;
 799         const char *value;
 800         int daemonize = 0;
 801         int i;
 802         int rc = 0;
 803         int maxfd;
 804
 805         /* redirect std fd's, if the kernel forks us, we don't have them at all */
 806         fd = open("/dev/null", O_RDWR);
 807         if (fd >= 0) {
 808                 if (fd != STDIN_FILENO)
 809                         dup2(fd, STDIN_FILENO);
 810                 if (fd != STDOUT_FILENO)
 811                         dup2(fd, STDOUT_FILENO);
 812                 if (fd != STDERR_FILENO)
 813                         dup2(fd, STDERR_FILENO);
 814                 if (fd > STDERR_FILENO)
 815                         close(fd);
 816         }
 817
 818         logging_init("udevd");
 819         if (fd < 0)
 820                 err("fatal, could not open /dev/null: %s", strerror(errno));
 821
 822         udev_init_config();
 823         dbg("version %s", UDEV_VERSION);
 824
 825         if (getuid() != 0) {
 826                 err("need to be root, exit");
 827                 goto exit;
 828         }
 829
 830         /* parse commandline options */
 831         for (i = 1 ; i < argc; i++) {
 832                 char *arg = argv[i];
 833                 if (strcmp(arg, "--daemon") == 0 || strcmp(arg, "-d") == 0) {
 834                         info("will daemonize");
 835                         daemonize = 1;
 836                 }
 837                 if (strcmp(arg, "--stop-exec-queue") == 0) {
 838                         info("will not execute events until START_EXEC_QUEUE is received");
 839                         stop_exec_q = 1;
 840                 }
 841         }
 842
 843         /* init sockets to receive events */
 844         if (init_udevd_socket() < 0) {
 845                 if (errno == EADDRINUSE) {
 846                         err("another udevd running, exit");
 847                         rc = 1;
 848                 } else {
 849                         err("error initializing udevd socket: %s", strerror(errno));
 850                         rc = 2;
 851                 }
 852                 goto exit;
 853         }
 854
 855         if (init_uevent_netlink_sock() < 0) {
 856                 err("uevent socket not available");
 857                 rc = 3;
 858                 goto exit;
 859         }
 860
 861         /* parse the rules and keep it in memory */
 862         udev_rules_init(&rules, 1);
 863
 864         if (daemonize) {
 865                 pid_t pid;
 866
 867                 pid = fork();
 868                 switch (pid) {
 869                 case 0:
 870                         dbg("daemonized fork running");
 871                         break;
 872                 case -1:
 873                         err("fork of daemon failed: %s", strerror(errno));
 874                         rc = 4;
 875                         goto exit;
 876                 default:
 877                         dbg("child [%u] running, parent exits", pid);
 878                         goto exit;
 879                 }
 880         }
 881
 882         /* set scheduling priority for the daemon */
 883         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 884
 885         chdir("/");
 886         umask(022);
 887
 888         /* become session leader */
 889         sid = setsid();
 890         dbg("our session is %d", sid);
 891
 892         /* OOM_DISABLE == -17 */
 893         fd = open("/proc/self/oom_adj", O_RDWR);
 894         if (fd < 0)
 895                 err("error disabling OOM: %s", strerror(errno));
 896         else {
 897                 write(fd, "-17", 3);
 898                 close(fd);
 899         }
 900
 901         /* setup signal handler pipe */
 902         retval = pipe(signal_pipe);
 903         if (retval < 0) {
 904                 err("error getting pipes: %s", strerror(errno));
 905                 goto exit;
 906         }
 907         retval = fcntl(signal_pipe[READ_END], F_SETFL, O_NONBLOCK);
 908         if (retval < 0) {
 909                 err("error fcntl on read pipe: %s", strerror(errno));
 910                 goto exit;
 911         }
 912         retval = fcntl(signal_pipe[WRITE_END], F_SETFL, O_NONBLOCK);
 913         if (retval < 0) {
 914                 err("error fcntl on write pipe: %s", strerror(errno));
 915                 goto exit;
 916         }
 917
 918         /* set signal handlers */
 919         memset(&act, 0x00, sizeof(struct sigaction));
 920         act.sa_handler = (void (*)(int)) sig_handler;
 921         sigemptyset(&act.sa_mask);
 922         act.sa_flags = SA_RESTART;
 923         sigaction(SIGINT, &act, NULL);
 924         sigaction(SIGTERM, &act, NULL);
 925         sigaction(SIGCHLD, &act, NULL);
 926         sigaction(SIGHUP, &act, NULL);
 927
 928         /* watch rules directory */
 929         inotify_fd = inotify_init();
 930         if (inotify_fd > 0)
 931                 inotify_add_watch(inotify_fd, udev_rules_filename, IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 932
 933         /* maximum limit of forked childs */
 934         value = getenv("UDEVD_MAX_CHILDS");
 935         if (value)
 936                 max_childs = strtoul(value, NULL, 10);
 937         else
 938                 max_childs = UDEVD_MAX_CHILDS;
 939         info("initialize max_childs to %u", max_childs);
 940
 941         /* start to throttle forking if maximum number of _running_ childs is reached */
 942         value = getenv("UDEVD_MAX_CHILDS_RUNNING");
 943         if (value)
 944                 max_childs_running = strtoull(value, NULL, 10);
 945         else
 946                 max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
 947         info("initialize max_childs_running to %u", max_childs_running);
 948
 949         /* clear environment for forked event processes */
 950         clearenv();
 951
 952         /* export log_priority , as called programs may want to follow that setting */
 953         sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
 954         putenv(udev_log);
 955
 956         maxfd = udevd_sock;
 957         maxfd = UDEV_MAX(maxfd, uevent_netlink_sock);
 958         maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
 959         maxfd = UDEV_MAX(maxfd, inotify_fd);
 960
 961         while (!udev_exit) {
 962                 struct uevent_msg *msg;
 963                 int fdcount;
 964
 965                 FD_ZERO(&readfds);
 966                 FD_SET(signal_pipe[READ_END], &readfds);
 967                 FD_SET(udevd_sock, &readfds);
 968                 FD_SET(uevent_netlink_sock, &readfds);
 969                 if (inotify_fd > 0)
 970                         FD_SET(inotify_fd, &readfds);
 971
 972                 fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
 973                 if (fdcount < 0) {
 974                         if (errno != EINTR)
 975                                 err("error in select: %s", strerror(errno));
 976                         continue;
 977                 }
 978
 979                 /* get user socket message */
 980                 if (FD_ISSET(udevd_sock, &readfds)) {
 981                         msg = get_udevd_msg();
 982                         if (msg) {
 983                                 if (msg->type == UDEVD_UEVENT_UDEVSEND && msg->seqnum != 0) {
 984                                         info("skip non-kernel message with SEQNUM");
 985                                         free(msg);
 986                                 } else
 987                                         msg_queue_insert(msg);
 988                         }
 989                 }
 990
 991                 /* get kernel netlink message */
 992                 if (FD_ISSET(uevent_netlink_sock, &readfds)) {
 993                         msg = get_netlink_msg();
 994                         if (msg)
 995                                 msg_queue_insert(msg);
 996                 }
 997
 998                 /* received a signal, clear our notification pipe */
 999                 if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
1000                         char buf[256];
1001
1002                         read(signal_pipe[READ_END], &buf, sizeof(buf));
1003                 }
1004
1005                 /* rules directory inotify watch */
1006                 if ((inotify_fd > 0) && FD_ISSET(inotify_fd, &readfds)) {
1007                         int nbytes;
1008
1009                         /* discard all possible events, we can just reload the config */
1010                         if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes) {
1011                                 char *buf;
1012
1013                                 reload_config = 1;
1014                                 buf = malloc(nbytes);
1015                                 if (!buf) {
1016                                         err("error getting buffer for inotify, disable watching");
1017                                         close(inotify_fd);
1018                                         inotify_fd = -1;
1019                                 }
1020                                 read(inotify_fd, buf, nbytes);
1021                                 free(buf);
1022                         }
1023                 }
1024
1025                 /* rules changed, set by inotify or a signal*/
1026                 if (reload_config) {
1027                         reload_config = 0;
1028                         udev_rules_close(&rules);
1029                         udev_rules_init(&rules, 1);
1030                 }
1031
1032                 /* forked child has returned */
1033                 if (sigchilds_waiting) {
1034                         sigchilds_waiting = 0;
1035                         reap_sigchilds();
1036                 }
1037
1038                 if (run_exec_q) {
1039                         run_exec_q = 0;
1040                         if (!stop_exec_q)
1041                                 msg_queue_manager();
1042                 }
1043         }
1044
1045 exit:
1046         udev_rules_close(&rules);
1047
1048         if (signal_pipe[READ_END] > 0)
1049                 close(signal_pipe[READ_END]);
1050         if (signal_pipe[WRITE_END] > 0)
1051                 close(signal_pipe[WRITE_END]);
1052
1053         if (udevd_sock > 0)
1054                 close(udevd_sock);
1055         if (inotify_fd > 0)
1056                 close(inotify_fd);
1057         if (uevent_netlink_sock > 0)
1058                 close(uevent_netlink_sock);
1059
1060         logging_close();
1061
1062         return rc;
1063 }