udev/udevd.c

   1 /*
   2  * Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
   3  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
   4  *
   5  *      This program is free software; you can redistribute it and/or modify it
   6  *      under the terms of the GNU General Public License as published by the
   7  *      Free Software Foundation version 2 of the License.
   8  *
   9  *      This program is distributed in the hope that it will be useful, but
  10  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *      General Public License for more details.
  13  *
  14  *      You should have received a copy of the GNU General Public License along
  15  *      with this program; if not, write to the Free Software Foundation, Inc.,
  16  *      51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  17  *
  18  */
  19
  20 #include "config.h"
  21
  22 #include <stddef.h>
  23 #include <signal.h>
  24 #include <unistd.h>
  25 #include <errno.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <ctype.h>
  30 #include <dirent.h>
  31 #include <fcntl.h>
  32 #include <syslog.h>
  33 #include <time.h>
  34 #include <getopt.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 #ifdef HAVE_INOTIFY
  45 #include <sys/inotify.h>
  46 #endif
  47
  48 #include "udev.h"
  49 #include "udev_rules.h"
  50 #include "udev_selinux.h"
  51
  52 #define UDEVD_PRIORITY                  -4
  53 #define UDEV_PRIORITY                   -2
  54
  55 /* maximum limit of forked childs */
  56 #define UDEVD_MAX_CHILDS                256
  57 /* start to throttle forking if maximum number of running childs in our session is reached */
  58 #define UDEVD_MAX_CHILDS_RUNNING        16
  59
  60 static int debug;
  61
  62 static void log_fn(struct udev *udev, int priority,
  63                    const char *file, int line, const char *fn,
  64                    const char *format, va_list args)
  65 {
  66         if (debug) {
  67                 fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
  68                 vfprintf(stderr, format, args);
  69         } else {
  70                 vsyslog(priority, format, args);
  71         }
  72 }
  73
  74 struct udevd_uevent_msg {
  75         struct udev *udev;
  76         struct list_head node;
  77         pid_t pid;
  78         int exitstatus;
  79         time_t queue_time;
  80         char *action;
  81         char *devpath;
  82         char *subsystem;
  83         char *driver;
  84         dev_t devt;
  85         unsigned long long seqnum;
  86         char *devpath_old;
  87         char *physdevpath;
  88         unsigned int timeout;
  89         char *envp[UEVENT_NUM_ENVP+1];
  90         char envbuf[];
  91 };
  92
  93 static int debug_trace;
  94 static struct udev_rules rules;
  95 static struct udev_ctrl *udev_ctrl;
  96 static int uevent_netlink_sock = -1;
  97 static int inotify_fd = -1;
  98 static pid_t sid;
  99
 100 static int signal_pipe[2] = {-1, -1};
 101 static volatile int sigchilds_waiting;
 102 static volatile int udev_exit;
 103 static volatile int reload_config;
 104 static int run_exec_q;
 105 static int stop_exec_q;
 106 static int max_childs;
 107 static int max_childs_running;
 108 static char udev_log_env[32];
 109
 110 static LIST_HEAD(exec_list);
 111 static LIST_HEAD(running_list);
 112
 113 static void asmlinkage udev_event_sig_handler(int signum)
 114 {
 115         if (signum == SIGALRM)
 116                 exit(1);
 117 }
 118
 119 static int udev_event_process(struct udevd_uevent_msg *msg)
 120 {
 121         struct sigaction act;
 122         struct udevice *udevice;
 123         int i;
 124         int retval;
 125
 126         /* set signal handlers */
 127         memset(&act, 0x00, sizeof(act));
 128         act.sa_handler = (void (*)(int)) udev_event_sig_handler;
 129         sigemptyset (&act.sa_mask);
 130         act.sa_flags = 0;
 131         sigaction(SIGALRM, &act, NULL);
 132
 133         /* reset to default */
 134         act.sa_handler = SIG_DFL;
 135         sigaction(SIGINT, &act, NULL);
 136         sigaction(SIGTERM, &act, NULL);
 137         sigaction(SIGCHLD, &act, NULL);
 138         sigaction(SIGHUP, &act, NULL);
 139
 140         /* trigger timeout to prevent hanging processes */
 141         alarm(UDEV_EVENT_TIMEOUT);
 142
 143         /* reconstruct event environment from message */
 144         for (i = 0; msg->envp[i]; i++)
 145                 putenv(msg->envp[i]);
 146
 147         udevice = udev_device_init(msg->udev);
 148         if (udevice == NULL)
 149                 return -1;
 150         strlcpy(udevice->action, msg->action, sizeof(udevice->action));
 151         sysfs_device_set_values(udevice->udev, udevice->dev, msg->devpath, msg->subsystem, msg->driver);
 152         udevice->devpath_old = msg->devpath_old;
 153         udevice->devt = msg->devt;
 154
 155         retval = udev_device_event(&rules, udevice);
 156
 157         /* rules may change/disable the timeout */
 158         if (udevice->event_timeout >= 0)
 159                 alarm(udevice->event_timeout);
 160
 161         /* run programs collected by RUN-key*/
 162         if (retval == 0 && !udevice->ignore_device && udev_get_run(msg->udev))
 163                 retval = udev_rules_run(udevice);
 164
 165         udev_device_cleanup(udevice);
 166         return retval;
 167 }
 168
 169 enum event_state {
 170         EVENT_QUEUED,
 171         EVENT_FINISHED,
 172         EVENT_FAILED,
 173 };
 174
 175 static void export_event_state(struct udevd_uevent_msg *msg, enum event_state state)
 176 {
 177         char filename[PATH_SIZE];
 178         char filename_failed[PATH_SIZE];
 179         size_t start;
 180
 181         /* location of queue file */
 182         snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu", udev_get_dev_path(msg->udev), msg->seqnum);
 183
 184         /* location of failed file */
 185         strlcpy(filename_failed, udev_get_dev_path(msg->udev), sizeof(filename_failed));
 186         strlcat(filename_failed, "/", sizeof(filename_failed));
 187         start = strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
 188         strlcat(filename_failed, msg->devpath, sizeof(filename_failed));
 189         path_encode(&filename_failed[start], sizeof(filename_failed) - start);
 190
 191         switch (state) {
 192         case EVENT_QUEUED:
 193                 unlink(filename_failed);
 194                 delete_path(msg->udev, filename_failed);
 195                 create_path(msg->udev, filename);
 196                 selinux_setfscreatecon(msg->udev, filename, NULL, S_IFLNK);
 197                 symlink(msg->devpath, filename);
 198                 selinux_resetfscreatecon(msg->udev);
 199                 break;
 200         case EVENT_FINISHED:
 201                 if (msg->devpath_old != NULL) {
 202                         /* "move" event - rename failed file to current name, do not delete failed */
 203                         char filename_failed_old[PATH_SIZE];
 204
 205                         strlcpy(filename_failed_old, udev_get_dev_path(msg->udev), sizeof(filename_failed_old));
 206                         strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
 207                         start = strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
 208                         strlcat(filename_failed_old, msg->devpath_old, sizeof(filename_failed_old));
 209                         path_encode(&filename_failed_old[start], sizeof(filename) - start);
 210
 211                         if (rename(filename_failed_old, filename_failed) == 0)
 212                                 info(msg->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
 213                                      msg->devpath_old, msg->devpath);
 214                 } else {
 215                         unlink(filename_failed);
 216                         delete_path(msg->udev, filename_failed);
 217                 }
 218
 219                 unlink(filename);
 220                 delete_path(msg->udev, filename);
 221                 break;
 222         case EVENT_FAILED:
 223                 /* move failed event to the failed directory */
 224                 create_path(msg->udev, filename_failed);
 225                 rename(filename, filename_failed);
 226
 227                 /* clean up possibly empty queue directory */
 228                 delete_path(msg->udev, filename);
 229                 break;
 230         }
 231
 232         return;
 233 }
 234
 235 static void msg_queue_delete(struct udevd_uevent_msg *msg)
 236 {
 237         list_del(&msg->node);
 238
 239         /* mark as failed, if "add" event returns non-zero */
 240         if (msg->exitstatus && strcmp(msg->action, "add") == 0)
 241                 export_event_state(msg, EVENT_FAILED);
 242         else
 243                 export_event_state(msg, EVENT_FINISHED);
 244
 245         free(msg);
 246 }
 247
 248 static void udev_event_run(struct udevd_uevent_msg *msg)
 249 {
 250         pid_t pid;
 251         int retval;
 252
 253         pid = fork();
 254         switch (pid) {
 255         case 0:
 256                 /* child */
 257                 close(uevent_netlink_sock);
 258                 udev_ctrl_unref(udev_ctrl);
 259                 if (inotify_fd >= 0)
 260                         close(inotify_fd);
 261                 close(signal_pipe[READ_END]);
 262                 close(signal_pipe[WRITE_END]);
 263                 logging_close();
 264                 logging_init("udevd-event");
 265                 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 266
 267                 retval = udev_event_process(msg);
 268                 info(msg->udev, "seq %llu finished with %i\n", msg->seqnum, retval);
 269
 270                 logging_close();
 271                 if (retval)
 272                         exit(1);
 273                 exit(0);
 274         case -1:
 275                 err(msg->udev, "fork of child failed: %s\n", strerror(errno));
 276                 msg_queue_delete(msg);
 277                 break;
 278         default:
 279                 /* get SIGCHLD in main loop */
 280                 info(msg->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
 281                      msg->seqnum, pid,  msg->action, msg->subsystem, time(NULL) - msg->queue_time);
 282                 msg->pid = pid;
 283         }
 284 }
 285
 286 static void msg_queue_insert(struct udevd_uevent_msg *msg)
 287 {
 288         char filename[PATH_SIZE];
 289         int fd;
 290
 291         msg->queue_time = time(NULL);
 292
 293         export_event_state(msg, EVENT_QUEUED);
 294         info(msg->udev, "seq %llu queued, '%s' '%s'\n", msg->seqnum, msg->action, msg->subsystem);
 295
 296         strlcpy(filename, udev_get_dev_path(msg->udev), sizeof(filename));
 297         strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 298         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 299         if (fd >= 0) {
 300                 char str[32];
 301                 int len;
 302
 303                 len = sprintf(str, "%llu\n", msg->seqnum);
 304                 write(fd, str, len);
 305                 close(fd);
 306         }
 307
 308         /* run one event after the other in debug mode */
 309         if (debug_trace) {
 310                 list_add_tail(&msg->node, &running_list);
 311                 udev_event_run(msg);
 312                 waitpid(msg->pid, NULL, 0);
 313                 msg_queue_delete(msg);
 314                 return;
 315         }
 316
 317         /* run all events with a timeout set immediately */
 318         if (msg->timeout != 0) {
 319                 list_add_tail(&msg->node, &running_list);
 320                 udev_event_run(msg);
 321                 return;
 322         }
 323
 324         list_add_tail(&msg->node, &exec_list);
 325         run_exec_q = 1;
 326 }
 327
 328 static int mem_size_mb(void)
 329 {
 330         FILE* f;
 331         char buf[4096];
 332         long int memsize = -1;
 333
 334         f = fopen("/proc/meminfo", "r");
 335         if (f == NULL)
 336                 return -1;
 337
 338         while (fgets(buf, sizeof(buf), f) != NULL) {
 339                 long int value;
 340
 341                 if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
 342                         memsize = value / 1024;
 343                         break;
 344                 }
 345         }
 346
 347         fclose(f);
 348         return memsize;
 349 }
 350
 351 static int cpu_count(void)
 352 {
 353         FILE* f;
 354         char buf[4096];
 355         int count = 0;
 356
 357         f = fopen("/proc/stat", "r");
 358         if (f == NULL)
 359                 return -1;
 360
 361         while (fgets(buf, sizeof(buf), f) != NULL) {
 362                 if (strncmp(buf, "cpu", 3) == 0 && isdigit(buf[3]))
 363                         count++;
 364         }
 365
 366         fclose(f);
 367         if (count == 0)
 368                 return -1;
 369         return count;
 370 }
 371
 372 static int running_processes(void)
 373 {
 374         FILE* f;
 375         char buf[4096];
 376         int running = -1;
 377
 378         f = fopen("/proc/stat", "r");
 379         if (f == NULL)
 380                 return -1;
 381
 382         while (fgets(buf, sizeof(buf), f) != NULL) {
 383                 int value;
 384
 385                 if (sscanf(buf, "procs_running %u", &value) == 1) {
 386                         running = value;
 387                         break;
 388                 }
 389         }
 390
 391         fclose(f);
 392         return running;
 393 }
 394
 395 /* return the number of process es in our session, count only until limit */
 396 static int running_processes_in_session(pid_t session, int limit)
 397 {
 398         DIR *dir;
 399         struct dirent *dent;
 400         int running = 0;
 401
 402         dir = opendir("/proc");
 403         if (!dir)
 404                 return -1;
 405
 406         /* read process info from /proc */
 407         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 408                 int f;
 409                 char procdir[64];
 410                 char line[256];
 411                 const char *pos;
 412                 char state;
 413                 pid_t ppid, pgrp, sess;
 414                 int len;
 415
 416                 if (!isdigit(dent->d_name[0]))
 417                         continue;
 418
 419                 snprintf(procdir, sizeof(procdir), "/proc/%s/stat", dent->d_name);
 420                 procdir[sizeof(procdir)-1] = '\0';
 421
 422                 f = open(procdir, O_RDONLY);
 423                 if (f == -1)
 424                         continue;
 425
 426                 len = read(f, line, sizeof(line)-1);
 427                 close(f);
 428
 429                 if (len <= 0)
 430                         continue;
 431                 else
 432                         line[len] = '\0';
 433
 434                 /* skip ugly program name */
 435                 pos = strrchr(line, ')') + 2;
 436                 if (pos == NULL)
 437                         continue;
 438
 439                 if (sscanf(pos, "%c %d %d %d ", &state, &ppid, &pgrp, &sess) != 4)
 440                         continue;
 441
 442                 /* count only processes in our session */
 443                 if (sess != session)
 444                         continue;
 445
 446                 /* count only running, no sleeping processes */
 447                 if (state != 'R')
 448                         continue;
 449
 450                 running++;
 451                 if (limit > 0 && running >= limit)
 452                         break;
 453         }
 454         closedir(dir);
 455
 456         return running;
 457 }
 458
 459 static int compare_devpath(const char *running, const char *waiting)
 460 {
 461         int i;
 462
 463         for (i = 0; i < PATH_SIZE; i++) {
 464                 /* identical device event found */
 465                 if (running[i] == '\0' && waiting[i] == '\0')
 466                         return 1;
 467
 468                 /* parent device event found */
 469                 if (running[i] == '\0' && waiting[i] == '/')
 470                         return 2;
 471
 472                 /* child device event found */
 473                 if (running[i] == '/' && waiting[i] == '\0')
 474                         return 3;
 475
 476                 /* no matching event */
 477                 if (running[i] != waiting[i])
 478                         break;
 479         }
 480
 481         return 0;
 482 }
 483
 484 /* lookup event for identical, parent, child, or physical device */
 485 static int devpath_busy(struct udevd_uevent_msg *msg, int limit)
 486 {
 487         struct udevd_uevent_msg *loop_msg;
 488         int childs_count = 0;
 489
 490         /* check exec-queue which may still contain delayed events we depend on */
 491         list_for_each_entry(loop_msg, &exec_list, node) {
 492                 /* skip ourself and all later events */
 493                 if (loop_msg->seqnum >= msg->seqnum)
 494                         break;
 495
 496                 /* check our old name */
 497                 if (msg->devpath_old != NULL)
 498                         if (strcmp(loop_msg->devpath , msg->devpath_old) == 0)
 499                                 return 2;
 500
 501                 /* check identical, parent, or child device event */
 502                 if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
 503                         dbg(msg->udev, "%llu, device event still pending %llu (%s)\n",
 504                             msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
 505                         return 3;
 506                 }
 507
 508                 /* check for our major:minor number */
 509                 if (msg->devt && loop_msg->devt == msg->devt &&
 510                     strcmp(msg->subsystem, loop_msg->subsystem) == 0) {
 511                         dbg(msg->udev, "%llu, device event still pending %llu (%d:%d)\n", msg->seqnum,
 512                             loop_msg->seqnum, major(loop_msg->devt), minor(loop_msg->devt));
 513                         return 4;
 514                 }
 515
 516                 /* check physical device event (special case of parent) */
 517                 if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
 518                         if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
 519                                 dbg(msg->udev, "%llu, physical device event still pending %llu (%s)\n",
 520                                     msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
 521                                 return 5;
 522                         }
 523         }
 524
 525         /* check run queue for still running events */
 526         list_for_each_entry(loop_msg, &running_list, node) {
 527                 if (limit && childs_count++ > limit) {
 528                         dbg(msg->udev, "%llu, maximum number (%i) of childs reached\n", msg->seqnum, childs_count);
 529                         return 1;
 530                 }
 531
 532                 /* check our old name */
 533                 if (msg->devpath_old != NULL)
 534                         if (strcmp(loop_msg->devpath , msg->devpath_old) == 0)
 535                                 return 2;
 536
 537                 /* check identical, parent, or child device event */
 538                 if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
 539                         dbg(msg->udev, "%llu, device event still running %llu (%s)\n",
 540                             msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
 541                         return 3;
 542                 }
 543
 544                 /* check for our major:minor number */
 545                 if (msg->devt && loop_msg->devt == msg->devt &&
 546                     strcmp(msg->subsystem, loop_msg->subsystem) == 0) {
 547                         dbg(msg->udev, "%llu, device event still running %llu (%d:%d)\n", msg->seqnum,
 548                             loop_msg->seqnum, major(loop_msg->devt), minor(loop_msg->devt));
 549                         return 4;
 550                 }
 551
 552                 /* check physical device event (special case of parent) */
 553                 if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
 554                         if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
 555                                 dbg(msg->udev, "%llu, physical device event still running %llu (%s)\n",
 556                                     msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
 557                                 return 5;
 558                         }
 559         }
 560         return 0;
 561 }
 562
 563 /* serializes events for the identical and parent and child devices */
 564 static void msg_queue_manager(struct udev *udev)
 565 {
 566         struct udevd_uevent_msg *loop_msg;
 567         struct udevd_uevent_msg *tmp_msg;
 568         int running;
 569
 570         if (list_empty(&exec_list))
 571                 return;
 572
 573         running = running_processes();
 574         dbg(udev, "%d processes runnning on system\n", running);
 575         if (running < 0)
 576                 running = max_childs_running;
 577
 578         list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) {
 579                 /* check running processes in our session and possibly throttle */
 580                 if (running >= max_childs_running) {
 581                         running = running_processes_in_session(sid, max_childs_running+10);
 582                         dbg(udev, "at least %d processes running in session\n", running);
 583                         if (running >= max_childs_running) {
 584                                 dbg(udev, "delay seq %llu, too many processes already running\n", loop_msg->seqnum);
 585                                 return;
 586                         }
 587                 }
 588
 589                 /* serialize and wait for parent or child events */
 590                 if (devpath_busy(loop_msg, max_childs) != 0) {
 591                         dbg(udev, "delay seq %llu (%s)\n", loop_msg->seqnum, loop_msg->devpath);
 592                         continue;
 593                 }
 594
 595                 /* move event to run list */
 596                 list_move_tail(&loop_msg->node, &running_list);
 597                 udev_event_run(loop_msg);
 598                 running++;
 599                 dbg(udev, "moved seq %llu to running list\n", loop_msg->seqnum);
 600         }
 601 }
 602
 603 static struct udevd_uevent_msg *get_msg_from_envbuf(struct udev *udev, const char *buf, int buf_size)
 604 {
 605         int bufpos;
 606         int i;
 607         struct udevd_uevent_msg *msg;
 608         char *physdevdriver_key = NULL;
 609         int maj = 0;
 610         int min = 0;
 611
 612         msg = malloc(sizeof(struct udevd_uevent_msg) + buf_size);
 613         if (msg == NULL)
 614                 return NULL;
 615         memset(msg, 0x00, sizeof(struct udevd_uevent_msg) + buf_size);
 616         msg->udev = udev;
 617
 618         /* copy environment buffer and reconstruct envp */
 619         memcpy(msg->envbuf, buf, buf_size);
 620         bufpos = 0;
 621         for (i = 0; (bufpos < buf_size) && (i < UEVENT_NUM_ENVP-2); i++) {
 622                 int keylen;
 623                 char *key;
 624
 625                 key = &msg->envbuf[bufpos];
 626                 keylen = strlen(key);
 627                 msg->envp[i] = key;
 628                 bufpos += keylen + 1;
 629                 dbg(udev, "add '%s' to msg.envp[%i]\n", msg->envp[i], i);
 630
 631                 /* remember some keys for further processing */
 632                 if (strncmp(key, "ACTION=", 7) == 0)
 633                         msg->action = &key[7];
 634                 else if (strncmp(key, "DEVPATH=", 8) == 0)
 635                         msg->devpath = &key[8];
 636                 else if (strncmp(key, "SUBSYSTEM=", 10) == 0)
 637                         msg->subsystem = &key[10];
 638                 else if (strncmp(key, "DRIVER=", 7) == 0)
 639                         msg->driver = &key[7];
 640                 else if (strncmp(key, "SEQNUM=", 7) == 0)
 641                         msg->seqnum = strtoull(&key[7], NULL, 10);
 642                 else if (strncmp(key, "DEVPATH_OLD=", 12) == 0)
 643                         msg->devpath_old = &key[12];
 644                 else if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
 645                         msg->physdevpath = &key[12];
 646                 else if (strncmp(key, "PHYSDEVDRIVER=", 14) == 0)
 647                         physdevdriver_key = key;
 648                 else if (strncmp(key, "MAJOR=", 6) == 0)
 649                         maj = strtoull(&key[6], NULL, 10);
 650                 else if (strncmp(key, "MINOR=", 6) == 0)
 651                         min = strtoull(&key[6], NULL, 10);
 652                 else if (strncmp(key, "TIMEOUT=", 8) == 0)
 653                         msg->timeout = strtoull(&key[8], NULL, 10);
 654         }
 655         msg->devt = makedev(maj, min);
 656         msg->envp[i++] = "UDEVD_EVENT=1";
 657
 658         if (msg->driver == NULL && msg->physdevpath == NULL && physdevdriver_key != NULL) {
 659                 /* for older kernels DRIVER is empty for a bus device, export PHYSDEVDRIVER as DRIVER */
 660                 msg->envp[i++] = &physdevdriver_key[7];
 661                 msg->driver = &physdevdriver_key[14];
 662         }
 663
 664         msg->envp[i] = NULL;
 665
 666         if (msg->devpath == NULL || msg->action == NULL) {
 667                 info(udev, "DEVPATH or ACTION missing, ignore message\n");
 668                 free(msg);
 669                 return NULL;
 670         }
 671         return msg;
 672 }
 673
 674 /* receive the udevd message from userspace */
 675 static void handle_ctrl_msg(struct udev_ctrl *uctrl)
 676 {
 677         struct udev *udev = udev_ctrl_get_udev(uctrl);
 678         struct udev_ctrl_msg *ctrl_msg;
 679         const char *str;
 680         int i;
 681
 682         ctrl_msg = udev_ctrl_receive_msg(uctrl);
 683         if (ctrl_msg == NULL)
 684                 return;
 685
 686         i = udev_ctrl_get_set_log_level(ctrl_msg);
 687         if (i >= 0) {
 688                 info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
 689                 udev_set_log_priority(udev, i);
 690                 sprintf(udev_log_env, "UDEV_LOG=%i", i);
 691                 putenv(udev_log_env);
 692         }
 693
 694         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
 695                 info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
 696                 stop_exec_q = 1;
 697         }
 698
 699         if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
 700                 info(udev, "udevd message (START_EXEC_QUEUE) received\n");
 701                 stop_exec_q = 0;
 702                 msg_queue_manager(udev);
 703         }
 704
 705         if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
 706                 info(udev, "udevd message (RELOAD_RULES) received\n");
 707                 reload_config = 1;
 708         }
 709
 710         str = udev_ctrl_get_set_env(ctrl_msg);
 711         if (str != NULL) {
 712                 char *key = strdup(str);
 713                 char *val;
 714
 715                 val = strchr(str, '=');
 716                 if (val != NULL) {
 717                         val[0] = '\0';
 718                         val = &val[1];
 719                         if (val[0] == '\0') {
 720                                 info(udev, "udevd message (ENV) received, unset '%s'\n", key);
 721                                 unsetenv(str);
 722                         } else {
 723                                 info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
 724                                 setenv(key, val, 1);
 725                         }
 726                 } else {
 727                         err(udev, "wrong key format '%s'\n", key);
 728                 }
 729                 free(key);
 730         }
 731
 732         i = udev_ctrl_get_set_max_childs(ctrl_msg);
 733         if (i >= 0) {
 734                 info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
 735                 max_childs = i;
 736         }
 737
 738         i = udev_ctrl_get_set_max_childs_running(ctrl_msg);
 739         if (i > 0) {
 740                 info(udev, "udevd message (SET_MAX_CHILDS_RUNNING) received, max_childs_running=%i\n", i);
 741                 max_childs_running = i;
 742         }
 743
 744         udev_ctrl_msg_unref(ctrl_msg);
 745 }
 746
 747 /* receive the kernel user event message and do some sanity checks */
 748 static struct udevd_uevent_msg *get_netlink_msg(struct udev *udev)
 749 {
 750         struct udevd_uevent_msg *msg;
 751         int bufpos;
 752         ssize_t size;
 753         static char buffer[UEVENT_BUFFER_SIZE+512];
 754         char *pos;
 755
 756         size = recv(uevent_netlink_sock, &buffer, sizeof(buffer), 0);
 757         if (size <  0) {
 758                 if (errno != EINTR)
 759                         err(udev, "unable to receive kernel netlink message: %s\n", strerror(errno));
 760                 return NULL;
 761         }
 762
 763         if ((size_t)size > sizeof(buffer)-1)
 764                 size = sizeof(buffer)-1;
 765         buffer[size] = '\0';
 766         dbg(udev, "uevent_size=%zi\n", size);
 767
 768         /* start of event payload */
 769         bufpos = strlen(buffer)+1;
 770         msg = get_msg_from_envbuf(udev, &buffer[bufpos], size-bufpos);
 771         if (msg == NULL)
 772                 return NULL;
 773
 774         /* validate message */
 775         pos = strchr(buffer, '@');
 776         if (pos == NULL) {
 777                 err(udev, "invalid uevent '%s'\n", buffer);
 778                 free(msg);
 779                 return NULL;
 780         }
 781         pos[0] = '\0';
 782
 783         if (msg->action == NULL) {
 784                 info(udev, "no ACTION in payload found, skip event '%s'\n", buffer);
 785                 free(msg);
 786                 return NULL;
 787         }
 788
 789         if (strcmp(msg->action, buffer) != 0) {
 790                 err(udev, "ACTION in payload does not match uevent, skip event '%s'\n", buffer);
 791                 free(msg);
 792                 return NULL;
 793         }
 794
 795         return msg;
 796 }
 797
 798 static void asmlinkage sig_handler(int signum)
 799 {
 800         switch (signum) {
 801                 case SIGINT:
 802                 case SIGTERM:
 803                         udev_exit = 1;
 804                         break;
 805                 case SIGCHLD:
 806                         /* set flag, then write to pipe if needed */
 807                         sigchilds_waiting = 1;
 808                         break;
 809                 case SIGHUP:
 810                         reload_config = 1;
 811                         break;
 812         }
 813
 814         /* write to pipe, which will wakeup select() in our mainloop */
 815         write(signal_pipe[WRITE_END], "", 1);
 816 }
 817
 818 static void udev_done(int pid, int exitstatus)
 819 {
 820         /* find msg associated with pid and delete it */
 821         struct udevd_uevent_msg *msg;
 822
 823         list_for_each_entry(msg, &running_list, node) {
 824                 if (msg->pid == pid) {
 825                         info(msg->udev, "seq %llu, pid [%d] exit with %i, %ld seconds old\n", msg->seqnum, msg->pid,
 826                              exitstatus, time(NULL) - msg->queue_time);
 827                         msg->exitstatus = exitstatus;
 828                         msg_queue_delete(msg);
 829
 830                         /* there may be events waiting with the same devpath */
 831                         run_exec_q = 1;
 832                         return;
 833                 }
 834         }
 835 }
 836
 837 static void reap_sigchilds(void)
 838 {
 839         pid_t pid;
 840         int status;
 841
 842         while (1) {
 843                 pid = waitpid(-1, &status, WNOHANG);
 844                 if (pid <= 0)
 845                         break;
 846                 if (WIFEXITED(status))
 847                         status = WEXITSTATUS(status);
 848                 else if (WIFSIGNALED(status))
 849                         status = WTERMSIG(status) + 128;
 850                 else
 851                         status = 0;
 852                 udev_done(pid, status);
 853         }
 854 }
 855
 856 static int init_uevent_netlink_sock(struct udev *udev)
 857 {
 858         struct sockaddr_nl snl;
 859         const int buffersize = 16 * 1024 * 1024;
 860         int retval;
 861
 862         memset(&snl, 0x00, sizeof(struct sockaddr_nl));
 863         snl.nl_family = AF_NETLINK;
 864         snl.nl_pid = getpid();
 865         snl.nl_groups = 1;
 866
 867         uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
 868         if (uevent_netlink_sock == -1) {
 869                 err(udev, "error getting socket: %s\n", strerror(errno));
 870                 return -1;
 871         }
 872
 873         /* set receive buffersize */
 874         setsockopt(uevent_netlink_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
 875
 876         retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl, sizeof(struct sockaddr_nl));
 877         if (retval < 0) {
 878                 err(udev, "bind failed: %s\n", strerror(errno));
 879                 close(uevent_netlink_sock);
 880                 uevent_netlink_sock = -1;
 881                 return -1;
 882         }
 883         return 0;
 884 }
 885
 886 static void export_initial_seqnum(struct udev *udev)
 887 {
 888         char filename[PATH_SIZE];
 889         int fd;
 890         char seqnum[32];
 891         ssize_t len = 0;
 892
 893         strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
 894         strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 895         fd = open(filename, O_RDONLY);
 896         if (fd >= 0) {
 897                 len = read(fd, seqnum, sizeof(seqnum)-1);
 898                 close(fd);
 899         }
 900         if (len <= 0) {
 901                 strcpy(seqnum, "0\n");
 902                 len = 3;
 903         }
 904         strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
 905         strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 906         create_path(udev, filename);
 907         fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
 908         if (fd >= 0) {
 909                 write(fd, seqnum, len);
 910                 close(fd);
 911         }
 912 }
 913
 914 int main(int argc, char *argv[])
 915 {
 916         struct udev *udev;
 917         int retval;
 918         int fd;
 919         struct sigaction act;
 920         fd_set readfds;
 921         const char *value;
 922         int daemonize = 0;
 923         static const struct option options[] = {
 924                 { "daemon", 0, NULL, 'd' },
 925                 { "debug-trace", 0, NULL, 't' },
 926                 { "debug", 0, NULL, 'D' },
 927                 { "help", 0, NULL, 'h' },
 928                 { "version", 0, NULL, 'V' },
 929                 {}
 930         };
 931         int rc = 1;
 932         int maxfd;
 933
 934         udev = udev_new();
 935         if (udev == NULL)
 936                 goto exit;
 937
 938         logging_init("udevd");
 939         udev_set_log_fn(udev, log_fn);
 940
 941         selinux_init(udev);
 942         dbg(udev, "version %s\n", VERSION);
 943
 944         while (1) {
 945                 int option;
 946
 947                 option = getopt_long(argc, argv, "dDthV", options, NULL);
 948                 if (option == -1)
 949                         break;
 950
 951                 switch (option) {
 952                 case 'd':
 953                         daemonize = 1;
 954                         break;
 955                 case 't':
 956                         debug_trace = 1;
 957                         break;
 958                 case 'D':
 959                         debug = 1;
 960                         if (udev_get_log_priority(udev) < LOG_INFO)
 961                                 udev_set_log_priority(udev, LOG_INFO);
 962                         break;
 963                 case 'h':
 964                         printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] [--version]\n");
 965                         goto exit;
 966                 case 'V':
 967                         printf("%s\n", VERSION);
 968                         goto exit;
 969                 default:
 970                         goto exit;
 971                 }
 972         }
 973
 974         if (getuid() != 0) {
 975                 fprintf(stderr, "root privileges required\n");
 976                 err(udev, "root privileges required\n");
 977                 goto exit;
 978         }
 979
 980         /* make sure std{in,out,err} fd's are in a sane state */
 981         fd = open("/dev/null", O_RDWR);
 982         if (fd < 0) {
 983                 fprintf(stderr, "cannot open /dev/null\n");
 984                 err(udev, "cannot open /dev/null\n");
 985         }
 986         if (fd > STDIN_FILENO)
 987                 dup2(fd, STDIN_FILENO);
 988         if (write(STDOUT_FILENO, 0, 0) < 0)
 989                 dup2(fd, STDOUT_FILENO);
 990         if (write(STDERR_FILENO, 0, 0) < 0)
 991                 dup2(fd, STDERR_FILENO);
 992
 993         /* init control socket, bind() ensures, that only one udevd instance is running */
 994         udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 995         if (udev_ctrl == NULL) {
 996                 fprintf(stderr, "error initializing control socket");
 997                 err(udev, "error initializing udevd socket");
 998                 rc = 1;
 999                 goto exit;
1000         }
1001
1002         if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
1003                 fprintf(stderr, "error binding control socket, seems udevd is already running\n");
1004                 err(udev, "error binding control socket, seems udevd is already running\n");
1005                 rc = 1;
1006                 goto exit;
1007         }
1008
1009         if (init_uevent_netlink_sock(udev) < 0) {
1010                 fprintf(stderr, "error initializing netlink socket\n");
1011                 err(udev, "error initializing netlink socket\n");
1012                 rc = 3;
1013                 goto exit;
1014         }
1015
1016         retval = pipe(signal_pipe);
1017         if (retval < 0) {
1018                 err(udev, "error getting pipes: %s\n", strerror(errno));
1019                 goto exit;
1020         }
1021
1022         retval = fcntl(signal_pipe[READ_END], F_GETFL, 0);
1023         if (retval < 0) {
1024                 err(udev, "error fcntl on read pipe: %s\n", strerror(errno));
1025                 goto exit;
1026         }
1027         retval = fcntl(signal_pipe[READ_END], F_SETFL, retval | O_NONBLOCK);
1028         if (retval < 0) {
1029                 err(udev, "error fcntl on read pipe: %s\n", strerror(errno));
1030                 goto exit;
1031         }
1032
1033         retval = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
1034         if (retval < 0) {
1035                 err(udev, "error fcntl on write pipe: %s\n", strerror(errno));
1036                 goto exit;
1037         }
1038         retval = fcntl(signal_pipe[WRITE_END], F_SETFL, retval | O_NONBLOCK);
1039         if (retval < 0) {
1040                 err(udev, "error fcntl on write pipe: %s\n", strerror(errno));
1041                 goto exit;
1042         }
1043
1044         /* parse the rules and keep them in memory */
1045         sysfs_init();
1046         udev_rules_init(udev, &rules, 1);
1047
1048         export_initial_seqnum(udev);
1049
1050         if (daemonize) {
1051                 pid_t pid;
1052
1053                 pid = fork();
1054                 switch (pid) {
1055                 case 0:
1056                         dbg(udev, "daemonized fork running\n");
1057                         break;
1058                 case -1:
1059                         err(udev, "fork of daemon failed: %s\n", strerror(errno));
1060                         rc = 4;
1061                         goto exit;
1062                 default:
1063                         dbg(udev, "child [%u] running, parent exits\n", pid);
1064                         rc = 0;
1065                         goto exit;
1066                 }
1067         }
1068
1069         /* redirect std{out,err} */
1070         if (!debug) {
1071                 dup2(fd, STDOUT_FILENO);
1072                 dup2(fd, STDERR_FILENO);
1073         }
1074         if (fd > STDERR_FILENO)
1075                 close(fd);
1076
1077         /* set scheduling priority for the daemon */
1078         setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
1079
1080         chdir("/");
1081         umask(022);
1082
1083         /* become session leader */
1084         sid = setsid();
1085         dbg(udev, "our session is %d\n", sid);
1086
1087         /* OOM_DISABLE == -17 */
1088         fd = open("/proc/self/oom_adj", O_RDWR);
1089         if (fd < 0)
1090                 err(udev, "error disabling OOM: %s\n", strerror(errno));
1091         else {
1092                 write(fd, "-17", 3);
1093                 close(fd);
1094         }
1095
1096         fd = open("/dev/kmsg", O_WRONLY);
1097         if (fd > 0) {
1098                 const char *str = "<6>udevd version " VERSION " started\n";
1099
1100                 write(fd, str, strlen(str));
1101                 close(fd);
1102         }
1103
1104         /* set signal handlers */
1105         memset(&act, 0x00, sizeof(struct sigaction));
1106         act.sa_handler = (void (*)(int)) sig_handler;
1107         sigemptyset(&act.sa_mask);
1108         act.sa_flags = SA_RESTART;
1109         sigaction(SIGINT, &act, NULL);
1110         sigaction(SIGTERM, &act, NULL);
1111         sigaction(SIGCHLD, &act, NULL);
1112         sigaction(SIGHUP, &act, NULL);
1113
1114         /* watch rules directory */
1115         inotify_fd = inotify_init();
1116         if (inotify_fd >= 0) {
1117                 if (udev_get_rules_path(udev) != NULL) {
1118                         inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
1119                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1120                 } else {
1121                         char filename[PATH_MAX];
1122
1123                         inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
1124                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1125                         inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
1126                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1127
1128                         /* watch dynamic rules directory */
1129                         strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
1130                         strlcat(filename, "/.udev/rules.d", sizeof(filename));
1131                         inotify_add_watch(inotify_fd, filename,
1132                                           IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1133                 }
1134         } else if (errno == ENOSYS)
1135                 err(udev, "the kernel does not support inotify, udevd can't monitor rules file changes\n");
1136         else
1137                 err(udev, "inotify_init failed: %s\n", strerror(errno));
1138
1139         /* maximum limit of forked childs */
1140         value = getenv("UDEVD_MAX_CHILDS");
1141         if (value)
1142                 max_childs = strtoul(value, NULL, 10);
1143         else {
1144                 int memsize = mem_size_mb();
1145                 if (memsize > 0)
1146                         max_childs = 128 + (memsize / 4);
1147                 else
1148                         max_childs = UDEVD_MAX_CHILDS;
1149         }
1150         info(udev, "initialize max_childs to %u\n", max_childs);
1151
1152         /* start to throttle forking if maximum number of _running_ childs is reached */
1153         value = getenv("UDEVD_MAX_CHILDS_RUNNING");
1154         if (value)
1155                 max_childs_running = strtoull(value, NULL, 10);
1156         else {
1157                 int cpus = cpu_count();
1158                 if (cpus > 0)
1159                         max_childs_running = 8 + (8 * cpus);
1160                 else
1161                         max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
1162         }
1163         info(udev, "initialize max_childs_running to %u\n", max_childs_running);
1164
1165         /* clear environment for forked event processes */
1166         clearenv();
1167
1168         /* export log_priority , as called programs may want to follow that setting */
1169         sprintf(udev_log_env, "UDEV_LOG=%i", udev_get_log_priority(udev));
1170         putenv(udev_log_env);
1171         if (debug_trace)
1172                 putenv("DEBUG=1");
1173
1174         maxfd = udev_ctrl_get_fd(udev_ctrl);
1175         maxfd = UDEV_MAX(maxfd, uevent_netlink_sock);
1176         maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
1177         maxfd = UDEV_MAX(maxfd, inotify_fd);
1178
1179         while (!udev_exit) {
1180                 struct udevd_uevent_msg *msg;
1181                 int fdcount;
1182
1183                 FD_ZERO(&readfds);
1184                 FD_SET(signal_pipe[READ_END], &readfds);
1185                 FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
1186                 FD_SET(uevent_netlink_sock, &readfds);
1187                 if (inotify_fd >= 0)
1188                         FD_SET(inotify_fd, &readfds);
1189
1190                 fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
1191                 if (fdcount < 0) {
1192                         if (errno != EINTR)
1193                                 err(udev, "error in select: %s\n", strerror(errno));
1194                         continue;
1195                 }
1196
1197                 /* get control message */
1198                 if (FD_ISSET(udev_ctrl_get_fd(udev_ctrl), &readfds))
1199                         handle_ctrl_msg(udev_ctrl);
1200
1201                 /* get netlink message */
1202                 if (FD_ISSET(uevent_netlink_sock, &readfds)) {
1203                         msg = get_netlink_msg(udev);
1204                         if (msg)
1205                                 msg_queue_insert(msg);
1206                 }
1207
1208                 /* received a signal, clear our notification pipe */
1209                 if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
1210                         char buf[256];
1211
1212                         read(signal_pipe[READ_END], &buf, sizeof(buf));
1213                 }
1214
1215                 /* rules directory inotify watch */
1216                 if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
1217                         int nbytes;
1218
1219                         /* discard all possible events, we can just reload the config */
1220                         if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
1221                                 char *buf;
1222
1223                                 reload_config = 1;
1224                                 buf = malloc(nbytes);
1225                                 if (buf == NULL) {
1226                                         err(udev, "error getting buffer for inotify, disable watching\n");
1227                                         close(inotify_fd);
1228                                         inotify_fd = -1;
1229                                 }
1230                                 read(inotify_fd, buf, nbytes);
1231                                 free(buf);
1232                         }
1233                 }
1234
1235                 /* rules changed, set by inotify or a HUP signal */
1236                 if (reload_config) {
1237                         reload_config = 0;
1238                         udev_rules_cleanup(&rules);
1239                         udev_rules_init(udev, &rules, 1);
1240                 }
1241
1242                 /* forked child has returned */
1243                 if (sigchilds_waiting) {
1244                         sigchilds_waiting = 0;
1245                         reap_sigchilds();
1246                 }
1247
1248                 if (run_exec_q) {
1249                         run_exec_q = 0;
1250                         if (!stop_exec_q)
1251                                 msg_queue_manager(udev);
1252                 }
1253         }
1254         rc = 0;
1255
1256 exit:
1257         udev_rules_cleanup(&rules);
1258         sysfs_cleanup();
1259         selinux_exit(udev);
1260
1261         if (signal_pipe[READ_END] >= 0)
1262                 close(signal_pipe[READ_END]);
1263         if (signal_pipe[WRITE_END] >= 0)
1264                 close(signal_pipe[WRITE_END]);
1265
1266         udev_ctrl_unref(udev_ctrl);
1267         if (inotify_fd >= 0)
1268                 close(inotify_fd);
1269         if (uevent_netlink_sock >= 0)
1270                 close(uevent_netlink_sock);
1271
1272         logging_close();
1273         return rc;
1274 }