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