src/udev/udev-event.c

   1 /*
   2  * Copyright (C) 2003-2013 Kay Sievers <kay@vrfy.org>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <stdlib.h>
  19 #include <stdio.h>
  20 #include <stddef.h>
  21 #include <unistd.h>
  22 #include <fcntl.h>
  23 #include <errno.h>
  24 #include <ctype.h>
  25 #include <string.h>
  26 #include <time.h>
  27 #include <net/if.h>
  28 #include <sys/prctl.h>
  29 #include <sys/poll.h>
  30 #include <sys/epoll.h>
  31 #include <sys/wait.h>
  32 #include <sys/signalfd.h>
  33
  34 #include "udev.h"
  35 #include "rtnl-util.h"
  36
  37 struct udev_event *udev_event_new(struct udev_device *dev) {
  38         struct udev *udev = udev_device_get_udev(dev);
  39         struct udev_event *event;
  40
  41         event = new0(struct udev_event, 1);
  42         if (event == NULL)
  43                 return NULL;
  44         event->dev = dev;
  45         event->udev = udev;
  46         udev_list_init(udev, &event->run_list, false);
  47         udev_list_init(udev, &event->seclabel_list, false);
  48         event->fd_signal = -1;
  49         event->birth_usec = now(CLOCK_MONOTONIC);
  50         return event;
  51 }
  52
  53 void udev_event_unref(struct udev_event *event) {
  54         if (event == NULL)
  55                 return;
  56         sd_rtnl_unref(event->rtnl);
  57         udev_list_cleanup(&event->run_list);
  58         udev_list_cleanup(&event->seclabel_list);
  59         free(event->program_result);
  60         free(event->name);
  61         free(event);
  62 }
  63
  64 size_t udev_event_apply_format(struct udev_event *event, const char *src, char *dest, size_t size) {
  65         struct udev_device *dev = event->dev;
  66         enum subst_type {
  67                 SUBST_UNKNOWN,
  68                 SUBST_DEVNODE,
  69                 SUBST_ATTR,
  70                 SUBST_ENV,
  71                 SUBST_KERNEL,
  72                 SUBST_KERNEL_NUMBER,
  73                 SUBST_DRIVER,
  74                 SUBST_DEVPATH,
  75                 SUBST_ID,
  76                 SUBST_MAJOR,
  77                 SUBST_MINOR,
  78                 SUBST_RESULT,
  79                 SUBST_PARENT,
  80                 SUBST_NAME,
  81                 SUBST_LINKS,
  82                 SUBST_ROOT,
  83                 SUBST_SYS,
  84         };
  85         static const struct subst_map {
  86                 const char *name;
  87                 const char fmt;
  88                 enum subst_type type;
  89         } map[] = {
  90                 { .name = "devnode",  .fmt = 'N', .type = SUBST_DEVNODE },
  91                 { .name = "tempnode", .fmt = 'N', .type = SUBST_DEVNODE },
  92                 { .name = "attr",     .fmt = 's', .type = SUBST_ATTR },
  93                 { .name = "sysfs",    .fmt = 's', .type = SUBST_ATTR },
  94                 { .name = "env",      .fmt = 'E', .type = SUBST_ENV },
  95                 { .name = "kernel",   .fmt = 'k', .type = SUBST_KERNEL },
  96                 { .name = "number",   .fmt = 'n', .type = SUBST_KERNEL_NUMBER },
  97                 { .name = "driver",   .fmt = 'd', .type = SUBST_DRIVER },
  98                 { .name = "devpath",  .fmt = 'p', .type = SUBST_DEVPATH },
  99                 { .name = "id",       .fmt = 'b', .type = SUBST_ID },
 100                 { .name = "major",    .fmt = 'M', .type = SUBST_MAJOR },
 101                 { .name = "minor",    .fmt = 'm', .type = SUBST_MINOR },
 102                 { .name = "result",   .fmt = 'c', .type = SUBST_RESULT },
 103                 { .name = "parent",   .fmt = 'P', .type = SUBST_PARENT },
 104                 { .name = "name",     .fmt = 'D', .type = SUBST_NAME },
 105                 { .name = "links",    .fmt = 'L', .type = SUBST_LINKS },
 106                 { .name = "root",     .fmt = 'r', .type = SUBST_ROOT },
 107                 { .name = "sys",      .fmt = 'S', .type = SUBST_SYS },
 108         };
 109         const char *from;
 110         char *s;
 111         size_t l;
 112
 113         from = src;
 114         s = dest;
 115         l = size;
 116
 117         for (;;) {
 118                 enum subst_type type = SUBST_UNKNOWN;
 119                 char attrbuf[UTIL_PATH_SIZE];
 120                 char *attr = NULL;
 121
 122                 while (from[0] != '\0') {
 123                         if (from[0] == '$') {
 124                                 /* substitute named variable */
 125                                 unsigned int i;
 126
 127                                 if (from[1] == '$') {
 128                                         from++;
 129                                         goto copy;
 130                                 }
 131
 132                                 for (i = 0; i < ELEMENTSOF(map); i++) {
 133                                         if (startswith(&from[1], map[i].name)) {
 134                                                 type = map[i].type;
 135                                                 from += strlen(map[i].name)+1;
 136                                                 goto subst;
 137                                         }
 138                                 }
 139                         } else if (from[0] == '%') {
 140                                 /* substitute format char */
 141                                 unsigned int i;
 142
 143                                 if (from[1] == '%') {
 144                                         from++;
 145                                         goto copy;
 146                                 }
 147
 148                                 for (i = 0; i < ELEMENTSOF(map); i++) {
 149                                         if (from[1] == map[i].fmt) {
 150                                                 type = map[i].type;
 151                                                 from += 2;
 152                                                 goto subst;
 153                                         }
 154                                 }
 155                         }
 156 copy:
 157                         /* copy char */
 158                         if (l == 0)
 159                                 goto out;
 160                         s[0] = from[0];
 161                         from++;
 162                         s++;
 163                         l--;
 164                 }
 165
 166                 goto out;
 167 subst:
 168                 /* extract possible $format{attr} */
 169                 if (from[0] == '{') {
 170                         unsigned int i;
 171
 172                         from++;
 173                         for (i = 0; from[i] != '}'; i++) {
 174                                 if (from[i] == '\0') {
 175                                         log_error("missing closing brace for format '%s'", src);
 176                                         goto out;
 177                                 }
 178                         }
 179                         if (i >= sizeof(attrbuf))
 180                                 goto out;
 181                         memcpy(attrbuf, from, i);
 182                         attrbuf[i] = '\0';
 183                         from += i+1;
 184                         attr = attrbuf;
 185                 } else {
 186                         attr = NULL;
 187                 }
 188
 189                 switch (type) {
 190                 case SUBST_DEVPATH:
 191                         l = strpcpy(&s, l, udev_device_get_devpath(dev));
 192                         break;
 193                 case SUBST_KERNEL:
 194                         l = strpcpy(&s, l, udev_device_get_sysname(dev));
 195                         break;
 196                 case SUBST_KERNEL_NUMBER:
 197                         if (udev_device_get_sysnum(dev) == NULL)
 198                                 break;
 199                         l = strpcpy(&s, l, udev_device_get_sysnum(dev));
 200                         break;
 201                 case SUBST_ID:
 202                         if (event->dev_parent == NULL)
 203                                 break;
 204                         l = strpcpy(&s, l, udev_device_get_sysname(event->dev_parent));
 205                         break;
 206                 case SUBST_DRIVER: {
 207                         const char *driver;
 208
 209                         if (event->dev_parent == NULL)
 210                                 break;
 211
 212                         driver = udev_device_get_driver(event->dev_parent);
 213                         if (driver == NULL)
 214                                 break;
 215                         l = strpcpy(&s, l, driver);
 216                         break;
 217                 }
 218                 case SUBST_MAJOR: {
 219                         char num[UTIL_PATH_SIZE];
 220
 221                         sprintf(num, "%d", major(udev_device_get_devnum(dev)));
 222                         l = strpcpy(&s, l, num);
 223                         break;
 224                 }
 225                 case SUBST_MINOR: {
 226                         char num[UTIL_PATH_SIZE];
 227
 228                         sprintf(num, "%d", minor(udev_device_get_devnum(dev)));
 229                         l = strpcpy(&s, l, num);
 230                         break;
 231                 }
 232                 case SUBST_RESULT: {
 233                         char *rest;
 234                         int i;
 235
 236                         if (event->program_result == NULL)
 237                                 break;
 238                         /* get part part of the result string */
 239                         i = 0;
 240                         if (attr != NULL)
 241                                 i = strtoul(attr, &rest, 10);
 242                         if (i > 0) {
 243                                 char result[UTIL_PATH_SIZE];
 244                                 char tmp[UTIL_PATH_SIZE];
 245                                 char *cpos;
 246
 247                                 strscpy(result, sizeof(result), event->program_result);
 248                                 cpos = result;
 249                                 while (--i) {
 250                                         while (cpos[0] != '\0' && !isspace(cpos[0]))
 251                                                 cpos++;
 252                                         while (isspace(cpos[0]))
 253                                                 cpos++;
 254                                         if (cpos[0] == '\0')
 255                                                 break;
 256                                 }
 257                                 if (i > 0) {
 258                                         log_error("requested part of result string not found");
 259                                         break;
 260                                 }
 261                                 strscpy(tmp, sizeof(tmp), cpos);
 262                                 /* %{2+}c copies the whole string from the second part on */
 263                                 if (rest[0] != '+') {
 264                                         cpos = strchr(tmp, ' ');
 265                                         if (cpos)
 266                                                 cpos[0] = '\0';
 267                                 }
 268                                 l = strpcpy(&s, l, tmp);
 269                         } else {
 270                                 l = strpcpy(&s, l, event->program_result);
 271                         }
 272                         break;
 273                 }
 274                 case SUBST_ATTR: {
 275                         const char *value = NULL;
 276                         char vbuf[UTIL_NAME_SIZE];
 277                         size_t len;
 278                         int count;
 279
 280                         if (attr == NULL) {
 281                                 log_error("missing file parameter for attr");
 282                                 break;
 283                         }
 284
 285                         /* try to read the value specified by "[dmi/id]product_name" */
 286                         if (util_resolve_subsys_kernel(event->udev, attr, vbuf, sizeof(vbuf), 1) == 0)
 287                                 value = vbuf;
 288
 289                         /* try to read the attribute the device */
 290                         if (value == NULL)
 291                                 value = udev_device_get_sysattr_value(event->dev, attr);
 292
 293                         /* try to read the attribute of the parent device, other matches have selected */
 294                         if (value == NULL && event->dev_parent != NULL && event->dev_parent != event->dev)
 295                                 value = udev_device_get_sysattr_value(event->dev_parent, attr);
 296
 297                         if (value == NULL)
 298                                 break;
 299
 300                         /* strip trailing whitespace, and replace unwanted characters */
 301                         if (value != vbuf)
 302                                 strscpy(vbuf, sizeof(vbuf), value);
 303                         len = strlen(vbuf);
 304                         while (len > 0 && isspace(vbuf[--len]))
 305                                 vbuf[len] = '\0';
 306                         count = util_replace_chars(vbuf, UDEV_ALLOWED_CHARS_INPUT);
 307                         if (count > 0)
 308                                 log_debug("%i character(s) replaced" , count);
 309                         l = strpcpy(&s, l, vbuf);
 310                         break;
 311                 }
 312                 case SUBST_PARENT: {
 313                         struct udev_device *dev_parent;
 314                         const char *devnode;
 315
 316                         dev_parent = udev_device_get_parent(event->dev);
 317                         if (dev_parent == NULL)
 318                                 break;
 319                         devnode = udev_device_get_devnode(dev_parent);
 320                         if (devnode != NULL)
 321                                 l = strpcpy(&s, l, devnode + strlen("/dev/"));
 322                         break;
 323                 }
 324                 case SUBST_DEVNODE:
 325                         if (udev_device_get_devnode(dev) != NULL)
 326                                 l = strpcpy(&s, l, udev_device_get_devnode(dev));
 327                         break;
 328                 case SUBST_NAME:
 329                         if (event->name != NULL)
 330                                 l = strpcpy(&s, l, event->name);
 331                         else if (udev_device_get_devnode(dev) != NULL)
 332                                 l = strpcpy(&s, l, udev_device_get_devnode(dev) + strlen("/dev/"));
 333                         else
 334                                 l = strpcpy(&s, l, udev_device_get_sysname(dev));
 335                         break;
 336                 case SUBST_LINKS: {
 337                         struct udev_list_entry *list_entry;
 338
 339                         list_entry = udev_device_get_devlinks_list_entry(dev);
 340                         if (list_entry == NULL)
 341                                 break;
 342                         l = strpcpy(&s, l, udev_list_entry_get_name(list_entry) + strlen("/dev/"));
 343                         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
 344                                 l = strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry) + strlen("/dev/"), NULL);
 345                         break;
 346                 }
 347                 case SUBST_ROOT:
 348                         l = strpcpy(&s, l, "/dev");
 349                         break;
 350                 case SUBST_SYS:
 351                         l = strpcpy(&s, l, "/sys");
 352                         break;
 353                 case SUBST_ENV:
 354                         if (attr == NULL) {
 355                                 break;
 356                         } else {
 357                                 const char *value;
 358
 359                                 value = udev_device_get_property_value(event->dev, attr);
 360                                 if (value == NULL)
 361                                         break;
 362                                 l = strpcpy(&s, l, value);
 363                                 break;
 364                         }
 365                 default:
 366                         log_error("unknown substitution type=%i", type);
 367                         break;
 368                 }
 369         }
 370
 371 out:
 372         s[0] = '\0';
 373         return l;
 374 }
 375
 376 static int spawn_exec(struct udev_event *event,
 377                       const char *cmd, char *const argv[], char **envp, const sigset_t *sigmask,
 378                       int fd_stdout, int fd_stderr) {
 379         _cleanup_close_ int fd = -1;
 380
 381         /* discard child output or connect to pipe */
 382         fd = open("/dev/null", O_RDWR);
 383         if (fd >= 0) {
 384                 dup2(fd, STDIN_FILENO);
 385                 if (fd_stdout < 0)
 386                         dup2(fd, STDOUT_FILENO);
 387                 if (fd_stderr < 0)
 388                         dup2(fd, STDERR_FILENO);
 389         } else
 390                 log_error_errno(errno, "open /dev/null failed: %m");
 391
 392         /* connect pipes to std{out,err} */
 393         if (fd_stdout >= 0) {
 394                 dup2(fd_stdout, STDOUT_FILENO);
 395                 safe_close(fd_stdout);
 396         }
 397         if (fd_stderr >= 0) {
 398                 dup2(fd_stderr, STDERR_FILENO);
 399                 safe_close(fd_stderr);
 400         }
 401
 402         /* terminate child in case parent goes away */
 403         prctl(PR_SET_PDEATHSIG, SIGTERM);
 404
 405         /* restore original udev sigmask before exec */
 406         if (sigmask)
 407                 sigprocmask(SIG_SETMASK, sigmask, NULL);
 408
 409         execve(argv[0], argv, envp);
 410
 411         /* exec failed */
 412         log_error_errno(errno, "failed to execute '%s' '%s': %m", argv[0], cmd);
 413
 414         return -errno;
 415 }
 416
 417 static void spawn_read(struct udev_event *event,
 418                        usec_t timeout_usec,
 419                        const char *cmd,
 420                        int fd_stdout, int fd_stderr,
 421                        char *result, size_t ressize) {
 422         _cleanup_close_ int fd_ep = -1;
 423         struct epoll_event ep_outpipe = {
 424                 .events = EPOLLIN,
 425                 .data.ptr = &fd_stdout,
 426         };
 427         struct epoll_event ep_errpipe = {
 428                 .events = EPOLLIN,
 429                 .data.ptr = &fd_stderr,
 430         };
 431         size_t respos = 0;
 432         int r;
 433
 434         /* read from child if requested */
 435         if (fd_stdout < 0 && fd_stderr < 0)
 436                 return;
 437
 438         fd_ep = epoll_create1(EPOLL_CLOEXEC);
 439         if (fd_ep < 0) {
 440                 log_error_errno(errno, "error creating epoll fd: %m");
 441                 return;
 442         }
 443
 444         if (fd_stdout >= 0) {
 445                 r = epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe);
 446                 if (r < 0) {
 447                         log_error_errno(errno, "fail to add stdout fd to epoll: %m");
 448                         return;
 449                 }
 450         }
 451
 452         if (fd_stderr >= 0) {
 453                 r = epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe);
 454                 if (r < 0) {
 455                         log_error_errno(errno, "fail to add stderr fd to epoll: %m");
 456                         return;
 457                 }
 458         }
 459
 460         /* read child output */
 461         while (fd_stdout >= 0 || fd_stderr >= 0) {
 462                 int timeout;
 463                 int fdcount;
 464                 struct epoll_event ev[4];
 465                 int i;
 466
 467                 if (timeout_usec > 0) {
 468                         usec_t age_usec;
 469
 470                         age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
 471                         if (age_usec >= timeout_usec) {
 472                                 log_error("timeout '%s'", cmd);
 473                                 return;
 474                         }
 475                         timeout = ((timeout_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
 476                 } else {
 477                         timeout = -1;
 478                 }
 479
 480                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
 481                 if (fdcount < 0) {
 482                         if (errno == EINTR)
 483                                 continue;
 484                         log_error_errno(errno, "failed to poll: %m");
 485                         return;
 486                 } else if (fdcount == 0) {
 487                         log_error("timeout '%s'", cmd);
 488                         return;
 489                 }
 490
 491                 for (i = 0; i < fdcount; i++) {
 492                         int *fd = (int *)ev[i].data.ptr;
 493
 494                         if (*fd < 0)
 495                                 continue;
 496
 497                         if (ev[i].events & EPOLLIN) {
 498                                 ssize_t count;
 499                                 char buf[4096];
 500
 501                                 count = read(*fd, buf, sizeof(buf)-1);
 502                                 if (count <= 0)
 503                                         continue;
 504                                 buf[count] = '\0';
 505
 506                                 /* store stdout result */
 507                                 if (result != NULL && *fd == fd_stdout) {
 508                                         if (respos + count < ressize) {
 509                                                 memcpy(&result[respos], buf, count);
 510                                                 respos += count;
 511                                         } else {
 512                                                 log_error("'%s' ressize %zd too short", cmd, ressize);
 513                                         }
 514                                 }
 515
 516                                 /* log debug output only if we watch stderr */
 517                                 if (fd_stderr >= 0) {
 518                                         char *pos;
 519                                         char *line;
 520
 521                                         pos = buf;
 522                                         while ((line = strsep(&pos, "\n"))) {
 523                                                 if (pos != NULL || line[0] != '\0')
 524                                                         log_debug("'%s'(%s) '%s'", cmd, *fd == fd_stdout ? "out" : "err" , line);
 525                                         }
 526                                 }
 527                         } else if (ev[i].events & EPOLLHUP) {
 528                                 r = epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL);
 529                                 if (r < 0) {
 530                                         log_error_errno(errno, "failed to remove fd from epoll: %m");
 531                                         return;
 532                                 }
 533                                 *fd = -1;
 534                         }
 535                 }
 536         }
 537
 538         /* return the child's stdout string */
 539         if (result != NULL)
 540                 result[respos] = '\0';
 541 }
 542
 543 static int spawn_wait(struct udev_event *event,
 544                       usec_t timeout_usec,
 545                       usec_t timeout_warn_usec,
 546                       const char *cmd, pid_t pid) {
 547         struct pollfd pfd[1];
 548         int err = 0;
 549
 550         pfd[0].events = POLLIN;
 551         pfd[0].fd = event->fd_signal;
 552
 553         while (pid > 0) {
 554                 int timeout;
 555                 int timeout_warn = 0;
 556                 int fdcount;
 557
 558                 if (timeout_usec > 0) {
 559                         usec_t age_usec;
 560
 561                         age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
 562                         if (age_usec >= timeout_usec)
 563                                 timeout = 1000;
 564                         else {
 565                                 if (timeout_warn_usec > 0)
 566                                         timeout_warn = ((timeout_warn_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
 567
 568                                 timeout = ((timeout_usec - timeout_warn_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
 569                         }
 570                 } else {
 571                         timeout = -1;
 572                 }
 573
 574                 fdcount = poll(pfd, 1, timeout_warn);
 575                 if (fdcount < 0) {
 576                         if (errno == EINTR)
 577                                 continue;
 578                         err = -errno;
 579                         log_error_errno(errno, "failed to poll: %m");
 580                         goto out;
 581                 }
 582                 if (fdcount == 0) {
 583                         log_warning("slow: '%s' [%u]", cmd, pid);
 584
 585                         fdcount = poll(pfd, 1, timeout);
 586                         if (fdcount < 0) {
 587                                 if (errno == EINTR)
 588                                         continue;
 589                                 err = -errno;
 590                                 log_error_errno(errno, "failed to poll: %m");
 591                                 goto out;
 592                         }
 593                         if (fdcount == 0) {
 594                                 log_error("timeout: killing '%s' [%u]", cmd, pid);
 595                                 kill(pid, SIGKILL);
 596                         }
 597                 }
 598
 599                 if (pfd[0].revents & POLLIN) {
 600                         struct signalfd_siginfo fdsi;
 601                         int status;
 602                         ssize_t size;
 603
 604                         size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 605                         if (size != sizeof(struct signalfd_siginfo))
 606                                 continue;
 607
 608                         switch (fdsi.ssi_signo) {
 609                         case SIGTERM:
 610                                 event->sigterm = true;
 611                                 break;
 612                         case SIGCHLD:
 613                                 if (waitpid(pid, &status, WNOHANG) < 0)
 614                                         break;
 615                                 if (WIFEXITED(status)) {
 616                                         log_debug("'%s' [%u] exit with return code %i", cmd, pid, WEXITSTATUS(status));
 617                                         if (WEXITSTATUS(status) != 0)
 618                                                 err = -1;
 619                                 } else if (WIFSIGNALED(status)) {
 620                                         log_error("'%s' [%u] terminated by signal %i (%s)", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 621                                         err = -1;
 622                                 } else if (WIFSTOPPED(status)) {
 623                                         log_error("'%s' [%u] stopped", cmd, pid);
 624                                         err = -1;
 625                                 } else if (WIFCONTINUED(status)) {
 626                                         log_error("'%s' [%u] continued", cmd, pid);
 627                                         err = -1;
 628                                 } else {
 629                                         log_error("'%s' [%u] exit with status 0x%04x", cmd, pid, status);
 630                                         err = -1;
 631                                 }
 632                                 pid = 0;
 633                                 break;
 634                         }
 635                 }
 636         }
 637 out:
 638         return err;
 639 }
 640
 641 int udev_build_argv(struct udev *udev, char *cmd, int *argc, char *argv[]) {
 642         int i = 0;
 643         char *pos;
 644
 645         if (strchr(cmd, ' ') == NULL) {
 646                 argv[i++] = cmd;
 647                 goto out;
 648         }
 649
 650         pos = cmd;
 651         while (pos != NULL && pos[0] != '\0') {
 652                 if (pos[0] == '\'') {
 653                         /* do not separate quotes */
 654                         pos++;
 655                         argv[i] = strsep(&pos, "\'");
 656                         if (pos != NULL)
 657                                 while (pos[0] == ' ')
 658                                         pos++;
 659                 } else {
 660                         argv[i] = strsep(&pos, " ");
 661                         if (pos != NULL)
 662                                 while (pos[0] == ' ')
 663                                         pos++;
 664                 }
 665                 i++;
 666         }
 667 out:
 668         argv[i] = NULL;
 669         if (argc)
 670                 *argc = i;
 671         return 0;
 672 }
 673
 674 int udev_event_spawn(struct udev_event *event,
 675                      usec_t timeout_usec,
 676                      usec_t timeout_warn_usec,
 677                      const char *cmd, char **envp, const sigset_t *sigmask,
 678                      char *result, size_t ressize) {
 679         int outpipe[2] = {-1, -1};
 680         int errpipe[2] = {-1, -1};
 681         pid_t pid;
 682         char arg[UTIL_PATH_SIZE];
 683         char *argv[128];
 684         char program[UTIL_PATH_SIZE];
 685         int err = 0;
 686
 687         strscpy(arg, sizeof(arg), cmd);
 688         udev_build_argv(event->udev, arg, NULL, argv);
 689
 690         /* pipes from child to parent */
 691         if (result != NULL || log_get_max_level() >= LOG_INFO) {
 692                 if (pipe2(outpipe, O_NONBLOCK) != 0) {
 693                         err = -errno;
 694                         log_error_errno(errno, "pipe failed: %m");
 695                         goto out;
 696                 }
 697         }
 698         if (log_get_max_level() >= LOG_INFO) {
 699                 if (pipe2(errpipe, O_NONBLOCK) != 0) {
 700                         err = -errno;
 701                         log_error_errno(errno, "pipe failed: %m");
 702                         goto out;
 703                 }
 704         }
 705
 706         /* allow programs in /usr/lib/udev/ to be called without the path */
 707         if (argv[0][0] != '/') {
 708                 strscpyl(program, sizeof(program), UDEVLIBEXECDIR "/", argv[0], NULL);
 709                 argv[0] = program;
 710         }
 711
 712         pid = fork();
 713         switch(pid) {
 714         case 0:
 715                 /* child closes parent's ends of pipes */
 716                 if (outpipe[READ_END] >= 0) {
 717                         close(outpipe[READ_END]);
 718                         outpipe[READ_END] = -1;
 719                 }
 720                 if (errpipe[READ_END] >= 0) {
 721                         close(errpipe[READ_END]);
 722                         errpipe[READ_END] = -1;
 723                 }
 724
 725                 log_debug("starting '%s'", cmd);
 726
 727                 spawn_exec(event, cmd, argv, envp, sigmask,
 728                            outpipe[WRITE_END], errpipe[WRITE_END]);
 729
 730                 _exit(2 );
 731         case -1:
 732                 log_error_errno(errno, "fork of '%s' failed: %m", cmd);
 733                 err = -1;
 734                 goto out;
 735         default:
 736                 /* parent closed child's ends of pipes */
 737                 if (outpipe[WRITE_END] >= 0) {
 738                         close(outpipe[WRITE_END]);
 739                         outpipe[WRITE_END] = -1;
 740                 }
 741                 if (errpipe[WRITE_END] >= 0) {
 742                         close(errpipe[WRITE_END]);
 743                         errpipe[WRITE_END] = -1;
 744                 }
 745
 746                 spawn_read(event,
 747                            timeout_usec,
 748                            cmd,
 749                            outpipe[READ_END], errpipe[READ_END],
 750                            result, ressize);
 751
 752                 err = spawn_wait(event, timeout_usec, timeout_warn_usec, cmd, pid);
 753         }
 754
 755 out:
 756         if (outpipe[READ_END] >= 0)
 757                 close(outpipe[READ_END]);
 758         if (outpipe[WRITE_END] >= 0)
 759                 close(outpipe[WRITE_END]);
 760         if (errpipe[READ_END] >= 0)
 761                 close(errpipe[READ_END]);
 762         if (errpipe[WRITE_END] >= 0)
 763                 close(errpipe[WRITE_END]);
 764         return err;
 765 }
 766
 767 static int rename_netif(struct udev_event *event) {
 768         struct udev_device *dev = event->dev;
 769         char name[IFNAMSIZ];
 770         const char *oldname;
 771         int r;
 772
 773         oldname = udev_device_get_sysname(dev);
 774
 775         strscpy(name, IFNAMSIZ, event->name);
 776
 777         r = rtnl_set_link_name(&event->rtnl, udev_device_get_ifindex(dev), name);
 778         if (r < 0)
 779                 return log_error_errno(r, "Error changing net interface name '%s' to '%s': %m", oldname, name);
 780
 781         log_debug("renamed network interface '%s' to '%s'", oldname, name);
 782
 783         return 0;
 784 }
 785
 786 void udev_event_execute_rules(struct udev_event *event,
 787                               usec_t timeout_usec, usec_t timeout_warn_usec,
 788                               struct udev_list *properties_list,
 789                               struct udev_rules *rules,
 790                               const sigset_t *sigmask) {
 791         struct udev_device *dev = event->dev;
 792
 793         if (udev_device_get_subsystem(dev) == NULL)
 794                 return;
 795
 796         if (streq(udev_device_get_action(dev), "remove")) {
 797                 udev_device_read_db(dev, NULL);
 798                 udev_device_delete_db(dev);
 799                 udev_device_tag_index(dev, NULL, false);
 800
 801                 if (major(udev_device_get_devnum(dev)) != 0)
 802                         udev_watch_end(event->udev, dev);
 803
 804                 udev_rules_apply_to_event(rules, event,
 805                                           timeout_usec, timeout_warn_usec,
 806                                           properties_list,
 807                                           sigmask);
 808
 809                 if (major(udev_device_get_devnum(dev)) != 0)
 810                         udev_node_remove(dev);
 811         } else {
 812                 event->dev_db = udev_device_new(event->udev);
 813                 if (event->dev_db != NULL) {
 814                         udev_device_set_syspath(event->dev_db, udev_device_get_syspath(dev));
 815                         udev_device_set_subsystem(event->dev_db, udev_device_get_subsystem(dev));
 816                         udev_device_set_devnum(event->dev_db, udev_device_get_devnum(dev));
 817                         udev_device_read_db(event->dev_db, NULL);
 818                         udev_device_set_info_loaded(event->dev_db);
 819
 820                         /* disable watch during event processing */
 821                         if (major(udev_device_get_devnum(dev)) != 0)
 822                                 udev_watch_end(event->udev, event->dev_db);
 823                 }
 824
 825                 if (major(udev_device_get_devnum(dev)) == 0 &&
 826                     streq(udev_device_get_action(dev), "move")) {
 827                         struct udev_list_entry *entry;
 828
 829                         for ((entry = udev_device_get_properties_list_entry(event->dev_db)); entry; entry = udev_list_entry_get_next(entry)) {
 830                                 const char *key, *value;
 831                                 struct udev_list_entry *property;
 832
 833                                 key = udev_list_entry_get_name(entry);
 834                                 value = udev_list_entry_get_value(entry);
 835
 836                                 property = udev_device_add_property(event->dev, key, value);
 837                                 udev_list_entry_set_num(property, true);
 838                         }
 839                 }
 840
 841                 udev_rules_apply_to_event(rules, event,
 842                                           timeout_usec, timeout_warn_usec,
 843                                           properties_list,
 844                                           sigmask);
 845
 846                 /* rename a new network interface, if needed */
 847                 if (udev_device_get_ifindex(dev) > 0 && streq(udev_device_get_action(dev), "add") &&
 848                     event->name != NULL && !streq(event->name, udev_device_get_sysname(dev))) {
 849                         char syspath[UTIL_PATH_SIZE];
 850                         char *pos;
 851                         int r;
 852
 853                         r = rename_netif(event);
 854                         if (r >= 0) {
 855                                 /* remember old name */
 856                                 udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
 857
 858                                 /* now change the devpath, because the kernel device name has changed */
 859                                 strscpy(syspath, sizeof(syspath), udev_device_get_syspath(dev));
 860                                 pos = strrchr(syspath, '/');
 861                                 if (pos != NULL) {
 862                                         pos++;
 863                                         strscpy(pos, sizeof(syspath) - (pos - syspath), event->name);
 864                                         udev_device_set_syspath(event->dev, syspath);
 865                                         udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
 866                                         log_debug("changed devpath to '%s'", udev_device_get_devpath(dev));
 867                                 }
 868                         }
 869                 }
 870
 871                 if (major(udev_device_get_devnum(dev)) > 0) {
 872                         bool apply;
 873
 874                         /* remove/update possible left-over symlinks from old database entry */
 875                         if (event->dev_db != NULL)
 876                                 udev_node_update_old_links(dev, event->dev_db);
 877
 878                         if (!event->owner_set)
 879                                 event->uid = udev_device_get_devnode_uid(dev);
 880
 881                         if (!event->group_set)
 882                                 event->gid = udev_device_get_devnode_gid(dev);
 883
 884                         if (!event->mode_set) {
 885                                 if (udev_device_get_devnode_mode(dev) > 0) {
 886                                         /* kernel supplied value */
 887                                         event->mode = udev_device_get_devnode_mode(dev);
 888                                 } else if (event->gid > 0) {
 889                                         /* default 0660 if a group is assigned */
 890                                         event->mode = 0660;
 891                                 } else {
 892                                         /* default 0600 */
 893                                         event->mode = 0600;
 894                                 }
 895                         }
 896
 897                         apply = streq(udev_device_get_action(dev), "add") || event->owner_set || event->group_set || event->mode_set;
 898                         udev_node_add(dev, apply, event->mode, event->uid, event->gid, &event->seclabel_list);
 899                 }
 900
 901                 /* preserve old, or get new initialization timestamp */
 902                 if (event->dev_db != NULL && udev_device_get_usec_initialized(event->dev_db) > 0)
 903                         udev_device_set_usec_initialized(event->dev, udev_device_get_usec_initialized(event->dev_db));
 904                 else if (udev_device_get_usec_initialized(event->dev) == 0)
 905                         udev_device_set_usec_initialized(event->dev, now(CLOCK_MONOTONIC));
 906
 907                 /* (re)write database file */
 908                 udev_device_update_db(dev);
 909                 udev_device_tag_index(dev, event->dev_db, true);
 910                 udev_device_set_is_initialized(dev);
 911
 912                 udev_device_unref(event->dev_db);
 913                 event->dev_db = NULL;
 914         }
 915 }
 916
 917 void udev_event_execute_run(struct udev_event *event, usec_t timeout_usec, usec_t timeout_warn_usec, const sigset_t *sigmask) {
 918         struct udev_list_entry *list_entry;
 919
 920         udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
 921                 const char *cmd = udev_list_entry_get_name(list_entry);
 922                 enum udev_builtin_cmd builtin_cmd = udev_list_entry_get_num(list_entry);
 923
 924                 if (builtin_cmd < UDEV_BUILTIN_MAX) {
 925                         char command[UTIL_PATH_SIZE];
 926
 927                         udev_event_apply_format(event, cmd, command, sizeof(command));
 928                         udev_builtin_run(event->dev, builtin_cmd, command, false);
 929                 } else {
 930                         char program[UTIL_PATH_SIZE];
 931                         char **envp;
 932
 933                         if (event->exec_delay > 0) {
 934                                 log_debug("delay execution of '%s'", program);
 935                                 sleep(event->exec_delay);
 936                         }
 937
 938                         udev_event_apply_format(event, cmd, program, sizeof(program));
 939                         envp = udev_device_get_properties_envp(event->dev);
 940                         udev_event_spawn(event, timeout_usec, timeout_warn_usec, program, envp, sigmask, NULL, 0);
 941                 }
 942         }
 943 }