src/udev/udev-event.c

   1 /*
   2  * Copyright (C) 2003-2010 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/ioctl.h>
  29 #include <sys/prctl.h>
  30 #include <sys/poll.h>
  31 #include <sys/epoll.h>
  32 #include <sys/wait.h>
  33 #include <sys/socket.h>
  34 #include <sys/signalfd.h>
  35 #include <linux/sockios.h>
  36
  37 #include "udev.h"
  38
  39 struct udev_event *udev_event_new(struct udev_device *dev)
  40 {
  41         struct udev *udev = udev_device_get_udev(dev);
  42         struct udev_event *event;
  43
  44         event = calloc(1, sizeof(struct udev_event));
  45         if (event == NULL)
  46                 return NULL;
  47         event->dev = dev;
  48         event->udev = udev;
  49         udev_list_init(udev, &event->run_list, false);
  50         event->fd_signal = -1;
  51         event->birth_usec = now(CLOCK_MONOTONIC);
  52         event->timeout_usec = 30 * 1000 * 1000;
  53         return event;
  54 }
  55
  56 void udev_event_unref(struct udev_event *event)
  57 {
  58         if (event == NULL)
  59                 return;
  60         udev_list_cleanup(&event->run_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'\n", 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                                 }
 258                                 if (i > 0) {
 259                                         log_error("requested part of result string not found\n");
 260                                         break;
 261                                 }
 262                                 strscpy(tmp, sizeof(tmp), cpos);
 263                                 /* %{2+}c copies the whole string from the second part on */
 264                                 if (rest[0] != '+') {
 265                                         cpos = strchr(tmp, ' ');
 266                                         if (cpos)
 267                                                 cpos[0] = '\0';
 268                                 }
 269                                 l = strpcpy(&s, l, tmp);
 270                         } else {
 271                                 l = strpcpy(&s, l, event->program_result);
 272                         }
 273                         break;
 274                 }
 275                 case SUBST_ATTR: {
 276                         const char *value = NULL;
 277                         char vbuf[UTIL_NAME_SIZE];
 278                         size_t len;
 279                         int count;
 280
 281                         if (attr == NULL) {
 282                                 log_error("missing file parameter for attr\n");
 283                                 break;
 284                         }
 285
 286                         /* try to read the value specified by "[dmi/id]product_name" */
 287                         if (util_resolve_subsys_kernel(event->udev, attr, vbuf, sizeof(vbuf), 1) == 0)
 288                                 value = vbuf;
 289
 290                         /* try to read the attribute the device */
 291                         if (value == NULL)
 292                                 value = udev_device_get_sysattr_value(event->dev, attr);
 293
 294                         /* try to read the attribute of the parent device, other matches have selected */
 295                         if (value == NULL && event->dev_parent != NULL && event->dev_parent != event->dev)
 296                                 value = udev_device_get_sysattr_value(event->dev_parent, attr);
 297
 298                         if (value == NULL)
 299                                 break;
 300
 301                         /* strip trailing whitespace, and replace unwanted characters */
 302                         if (value != vbuf)
 303                                 strscpy(vbuf, sizeof(vbuf), value);
 304                         len = strlen(vbuf);
 305                         while (len > 0 && isspace(vbuf[--len]))
 306                                 vbuf[len] = '\0';
 307                         count = util_replace_chars(vbuf, UDEV_ALLOWED_CHARS_INPUT);
 308                         if (count > 0)
 309                                 log_debug("%i character(s) replaced\n" , count);
 310                         l = strpcpy(&s, l, vbuf);
 311                         break;
 312                 }
 313                 case SUBST_PARENT: {
 314                         struct udev_device *dev_parent;
 315                         const char *devnode;
 316
 317                         dev_parent = udev_device_get_parent(event->dev);
 318                         if (dev_parent == NULL)
 319                                 break;
 320                         devnode = udev_device_get_devnode(dev_parent);
 321                         if (devnode != NULL)
 322                                 l = strpcpy(&s, l, devnode + strlen("/dev/"));
 323                         break;
 324                 }
 325                 case SUBST_DEVNODE:
 326                         if (udev_device_get_devnode(dev) != NULL)
 327                                 l = strpcpy(&s, l, udev_device_get_devnode(dev));
 328                         break;
 329                 case SUBST_NAME:
 330                         if (event->name != NULL)
 331                                 l = strpcpy(&s, l, event->name);
 332                         else if (udev_device_get_devnode(dev) != NULL)
 333                                 l = strpcpy(&s, l, udev_device_get_devnode(dev) + strlen("/dev/"));
 334                         else
 335                                 l = strpcpy(&s, l, udev_device_get_sysname(dev));
 336                         break;
 337                 case SUBST_LINKS: {
 338                         struct udev_list_entry *list_entry;
 339
 340                         list_entry = udev_device_get_devlinks_list_entry(dev);
 341                         if (list_entry == NULL)
 342                                 break;
 343                         l = strpcpy(&s, l, udev_list_entry_get_name(list_entry) + strlen("/dev/"));
 344                         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
 345                                 l = strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry) + strlen("/dev/"), NULL);
 346                         break;
 347                 }
 348                 case SUBST_ROOT:
 349                         l = strpcpy(&s, l, "/dev");
 350                         break;
 351                 case SUBST_SYS:
 352                         l = strpcpy(&s, l, "/sys");
 353                         break;
 354                 case SUBST_ENV:
 355                         if (attr == NULL) {
 356                                 break;
 357                         } else {
 358                                 const char *value;
 359
 360                                 value = udev_device_get_property_value(event->dev, attr);
 361                                 if (value == NULL)
 362                                         break;
 363                                 l = strpcpy(&s, l, value);
 364                                 break;
 365                         }
 366                 default:
 367                         log_error("unknown substitution type=%i\n", type);
 368                         break;
 369                 }
 370         }
 371
 372 out:
 373         s[0] = '\0';
 374         return l;
 375 }
 376
 377 static int spawn_exec(struct udev_event *event,
 378                       const char *cmd, char *const argv[], char **envp, const sigset_t *sigmask,
 379                       int fd_stdout, int fd_stderr)
 380 {
 381         int err;
 382         int fd;
 383
 384         /* discard child output or connect to pipe */
 385         fd = open("/dev/null", O_RDWR);
 386         if (fd >= 0) {
 387                 dup2(fd, STDIN_FILENO);
 388                 if (fd_stdout < 0)
 389                         dup2(fd, STDOUT_FILENO);
 390                 if (fd_stderr < 0)
 391                         dup2(fd, STDERR_FILENO);
 392                 close(fd);
 393         } else {
 394                 log_error("open /dev/null failed: %m\n");
 395         }
 396
 397         /* connect pipes to std{out,err} */
 398         if (fd_stdout >= 0) {
 399                 dup2(fd_stdout, STDOUT_FILENO);
 400                         close(fd_stdout);
 401         }
 402         if (fd_stderr >= 0) {
 403                 dup2(fd_stderr, STDERR_FILENO);
 404                 close(fd_stderr);
 405         }
 406
 407         /* terminate child in case parent goes away */
 408         prctl(PR_SET_PDEATHSIG, SIGTERM);
 409
 410         /* restore original udev sigmask before exec */
 411         if (sigmask)
 412                 sigprocmask(SIG_SETMASK, sigmask, NULL);
 413
 414         execve(argv[0], argv, envp);
 415
 416         /* exec failed */
 417         err = -errno;
 418         log_error("failed to execute '%s' '%s': %m\n", argv[0], cmd);
 419         return err;
 420 }
 421
 422 static void spawn_read(struct udev_event *event,
 423                       const char *cmd,
 424                       int fd_stdout, int fd_stderr,
 425                       char *result, size_t ressize)
 426 {
 427         size_t respos = 0;
 428         int fd_ep = -1;
 429         struct epoll_event ep_outpipe, ep_errpipe;
 430
 431         /* read from child if requested */
 432         if (fd_stdout < 0 && fd_stderr < 0)
 433                 return;
 434
 435         fd_ep = epoll_create1(EPOLL_CLOEXEC);
 436         if (fd_ep < 0) {
 437                 log_error("error creating epoll fd: %m\n");
 438                 goto out;
 439         }
 440
 441         if (fd_stdout >= 0) {
 442                 memset(&ep_outpipe, 0, sizeof(struct epoll_event));
 443                 ep_outpipe.events = EPOLLIN;
 444                 ep_outpipe.data.ptr = &fd_stdout;
 445                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe) < 0) {
 446                         log_error("fail to add fd to epoll: %m\n");
 447                         goto out;
 448                 }
 449         }
 450
 451         if (fd_stderr >= 0) {
 452                 memset(&ep_errpipe, 0, sizeof(struct epoll_event));
 453                 ep_errpipe.events = EPOLLIN;
 454                 ep_errpipe.data.ptr = &fd_stderr;
 455                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe) < 0) {
 456                         log_error("fail to add fd to epoll: %m\n");
 457                         goto out;
 458                 }
 459         }
 460
 461         /* read child output */
 462         while (fd_stdout >= 0 || fd_stderr >= 0) {
 463                 int timeout;
 464                 int fdcount;
 465                 struct epoll_event ev[4];
 466                 int i;
 467
 468                 if (event->timeout_usec > 0) {
 469                         usec_t age_usec;
 470
 471                         age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
 472                         if (age_usec >= event->timeout_usec) {
 473                                 log_error("timeout '%s'\n", cmd);
 474                                 goto out;
 475                         }
 476                         timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
 477                 } else {
 478                         timeout = -1;
 479                 }
 480
 481                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
 482                 if (fdcount < 0) {
 483                         if (errno == EINTR)
 484                                 continue;
 485                         log_error("failed to poll: %m\n");
 486                         goto out;
 487                 }
 488                 if (fdcount == 0) {
 489                         log_error("timeout '%s'\n", cmd);
 490                         goto out;
 491                 }
 492
 493                 for (i = 0; i < fdcount; i++) {
 494                         int *fd = (int *)ev[i].data.ptr;
 495
 496                         if (ev[i].events & EPOLLIN) {
 497                                 ssize_t count;
 498                                 char buf[4096];
 499
 500                                 count = read(*fd, buf, sizeof(buf)-1);
 501                                 if (count <= 0)
 502                                         continue;
 503                                 buf[count] = '\0';
 504
 505                                 /* store stdout result */
 506                                 if (result != NULL && *fd == fd_stdout) {
 507                                         if (respos + count < ressize) {
 508                                                 memcpy(&result[respos], buf, count);
 509                                                 respos += count;
 510                                         } else {
 511                                                 log_error("'%s' ressize %zd too short\n", cmd, ressize);
 512                                         }
 513                                 }
 514
 515                                 /* log debug output only if we watch stderr */
 516                                 if (fd_stderr >= 0) {
 517                                         char *pos;
 518                                         char *line;
 519
 520                                         pos = buf;
 521                                         while ((line = strsep(&pos, "\n"))) {
 522                                                 if (pos != NULL || line[0] != '\0')
 523                                                         log_debug("'%s'(%s) '%s'\n", cmd, *fd == fd_stdout ? "out" : "err" , line);
 524                                         }
 525                                 }
 526                         } else if (ev[i].events & EPOLLHUP) {
 527                                 if (epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL) < 0) {
 528                                         log_error("failed to remove fd from epoll: %m\n");
 529                                         goto out;
 530                                 }
 531                                 *fd = -1;
 532                         }
 533                 }
 534         }
 535
 536         /* return the child's stdout string */
 537         if (result != NULL)
 538                 result[respos] = '\0';
 539 out:
 540         if (fd_ep >= 0)
 541                 close(fd_ep);
 542 }
 543
 544 static int spawn_wait(struct udev_event *event, const char *cmd, pid_t pid)
 545 {
 546         struct pollfd pfd[1];
 547         int err = 0;
 548
 549         pfd[0].events = POLLIN;
 550         pfd[0].fd = event->fd_signal;
 551
 552         while (pid > 0) {
 553                 int timeout;
 554                 int fdcount;
 555
 556                 if (event->timeout_usec > 0) {
 557                         usec_t age_usec;
 558
 559                         age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
 560                         if (age_usec >= event->timeout_usec)
 561                                 timeout = 1000;
 562                         else
 563                                 timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
 564                 } else {
 565                         timeout = -1;
 566                 }
 567
 568                 fdcount = poll(pfd, 1, timeout);
 569                 if (fdcount < 0) {
 570                         if (errno == EINTR)
 571                                 continue;
 572                         err = -errno;
 573                         log_error("failed to poll: %m\n");
 574                         goto out;
 575                 }
 576                 if (fdcount == 0) {
 577                         log_error("timeout: killing '%s' [%u]\n", cmd, pid);
 578                         kill(pid, SIGKILL);
 579                 }
 580
 581                 if (pfd[0].revents & POLLIN) {
 582                         struct signalfd_siginfo fdsi;
 583                         int status;
 584                         ssize_t size;
 585
 586                         size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 587                         if (size != sizeof(struct signalfd_siginfo))
 588                                 continue;
 589
 590                         switch (fdsi.ssi_signo) {
 591                         case SIGTERM:
 592                                 event->sigterm = true;
 593                                 break;
 594                         case SIGCHLD:
 595                                 if (waitpid(pid, &status, WNOHANG) < 0)
 596                                         break;
 597                                 if (WIFEXITED(status)) {
 598                                         log_debug("'%s' [%u] exit with return code %i\n", cmd, pid, WEXITSTATUS(status));
 599                                         if (WEXITSTATUS(status) != 0)
 600                                                 err = -1;
 601                                 } else if (WIFSIGNALED(status)) {
 602                                         log_error("'%s' [%u] terminated by signal %i (%s)\n", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 603                                         err = -1;
 604                                 } else if (WIFSTOPPED(status)) {
 605                                         log_error("'%s' [%u] stopped\n", cmd, pid);
 606                                         err = -1;
 607                                 } else if (WIFCONTINUED(status)) {
 608                                         log_error("'%s' [%u] continued\n", cmd, pid);
 609                                         err = -1;
 610                                 } else {
 611                                         log_error("'%s' [%u] exit with status 0x%04x\n", cmd, pid, status);
 612                                         err = -1;
 613                                 }
 614                                 pid = 0;
 615                                 break;
 616                         }
 617                 }
 618         }
 619 out:
 620         return err;
 621 }
 622
 623 int udev_build_argv(struct udev *udev, char *cmd, int *argc, char *argv[])
 624 {
 625         int i = 0;
 626         char *pos;
 627
 628         if (strchr(cmd, ' ') == NULL) {
 629                 argv[i++] = cmd;
 630                 goto out;
 631         }
 632
 633         pos = cmd;
 634         while (pos != NULL && pos[0] != '\0') {
 635                 if (pos[0] == '\'') {
 636                         /* do not separate quotes */
 637                         pos++;
 638                         argv[i] = strsep(&pos, "\'");
 639                         if (pos != NULL)
 640                                 while (pos[0] == ' ')
 641                                         pos++;
 642                 } else {
 643                         argv[i] = strsep(&pos, " ");
 644                         if (pos != NULL)
 645                                 while (pos[0] == ' ')
 646                                         pos++;
 647                 }
 648                 i++;
 649         }
 650 out:
 651         argv[i] = NULL;
 652         if (argc)
 653                 *argc = i;
 654         return 0;
 655 }
 656
 657 int udev_event_spawn(struct udev_event *event,
 658                      const char *cmd, char **envp, const sigset_t *sigmask,
 659                      char *result, size_t ressize)
 660 {
 661         struct udev *udev = event->udev;
 662         int outpipe[2] = {-1, -1};
 663         int errpipe[2] = {-1, -1};
 664         pid_t pid;
 665         char arg[UTIL_PATH_SIZE];
 666         char *argv[128];
 667         char program[UTIL_PATH_SIZE];
 668         int err = 0;
 669
 670         strscpy(arg, sizeof(arg), cmd);
 671         udev_build_argv(event->udev, arg, NULL, argv);
 672
 673         /* pipes from child to parent */
 674         if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
 675                 if (pipe2(outpipe, O_NONBLOCK) != 0) {
 676                         err = -errno;
 677                         log_error("pipe failed: %m\n");
 678                         goto out;
 679                 }
 680         }
 681         if (udev_get_log_priority(udev) >= LOG_INFO) {
 682                 if (pipe2(errpipe, O_NONBLOCK) != 0) {
 683                         err = -errno;
 684                         log_error("pipe failed: %m\n");
 685                         goto out;
 686                 }
 687         }
 688
 689         /* allow programs in /usr/lib/udev/ to be called without the path */
 690         if (argv[0][0] != '/') {
 691                 strscpyl(program, sizeof(program), UDEVLIBEXECDIR "/", argv[0], NULL);
 692                 argv[0] = program;
 693         }
 694
 695         pid = fork();
 696         switch(pid) {
 697         case 0:
 698                 /* child closes parent's ends of pipes */
 699                 if (outpipe[READ_END] >= 0) {
 700                         close(outpipe[READ_END]);
 701                         outpipe[READ_END] = -1;
 702                 }
 703                 if (errpipe[READ_END] >= 0) {
 704                         close(errpipe[READ_END]);
 705                         errpipe[READ_END] = -1;
 706                 }
 707
 708                 log_debug("starting '%s'\n", cmd);
 709
 710                 spawn_exec(event, cmd, argv, envp, sigmask,
 711                            outpipe[WRITE_END], errpipe[WRITE_END]);
 712
 713                 _exit(2 );
 714         case -1:
 715                 log_error("fork of '%s' failed: %m\n", cmd);
 716                 err = -1;
 717                 goto out;
 718         default:
 719                 /* parent closed child's ends of pipes */
 720                 if (outpipe[WRITE_END] >= 0) {
 721                         close(outpipe[WRITE_END]);
 722                         outpipe[WRITE_END] = -1;
 723                 }
 724                 if (errpipe[WRITE_END] >= 0) {
 725                         close(errpipe[WRITE_END]);
 726                         errpipe[WRITE_END] = -1;
 727                 }
 728
 729                 spawn_read(event, cmd,
 730                          outpipe[READ_END], errpipe[READ_END],
 731                          result, ressize);
 732
 733                 err = spawn_wait(event, cmd, pid);
 734         }
 735
 736 out:
 737         if (outpipe[READ_END] >= 0)
 738                 close(outpipe[READ_END]);
 739         if (outpipe[WRITE_END] >= 0)
 740                 close(outpipe[WRITE_END]);
 741         if (errpipe[READ_END] >= 0)
 742                 close(errpipe[READ_END]);
 743         if (errpipe[WRITE_END] >= 0)
 744                 close(errpipe[WRITE_END]);
 745         return err;
 746 }
 747
 748 static int rename_netif(struct udev_event *event)
 749 {
 750         struct udev_device *dev = event->dev;
 751         int sk;
 752         struct ifreq ifr;
 753         int err;
 754
 755         log_debug("changing net interface name from '%s' to '%s'\n",
 756                   udev_device_get_sysname(dev), event->name);
 757
 758         sk = socket(PF_INET, SOCK_DGRAM, 0);
 759         if (sk < 0) {
 760                 err = -errno;
 761                 log_error("error opening socket: %m\n");
 762                 return err;
 763         }
 764
 765         memset(&ifr, 0x00, sizeof(struct ifreq));
 766         strscpy(ifr.ifr_name, IFNAMSIZ, udev_device_get_sysname(dev));
 767         strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
 768         err = ioctl(sk, SIOCSIFNAME, &ifr);
 769         if (err >= 0) {
 770                 print_kmsg("renamed network interface %s to %s\n", ifr.ifr_name, ifr.ifr_newname);
 771         } else {
 772                 err = -errno;
 773                 log_error("error changing net interface name %s to %s: %m\n", ifr.ifr_name, ifr.ifr_newname);
 774         }
 775         close(sk);
 776         return err;
 777 }
 778
 779 int 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         int err = 0;
 783
 784         if (udev_device_get_subsystem(dev) == NULL)
 785                 return -1;
 786
 787         if (strcmp(udev_device_get_action(dev), "remove") == 0) {
 788                 udev_device_read_db(dev, NULL);
 789                 udev_device_delete_db(dev);
 790                 udev_device_tag_index(dev, NULL, false);
 791
 792                 if (major(udev_device_get_devnum(dev)) != 0)
 793                         udev_watch_end(event->udev, dev);
 794
 795                 udev_rules_apply_to_event(rules, event, sigmask);
 796
 797                 if (major(udev_device_get_devnum(dev)) != 0)
 798                         udev_node_remove(dev);
 799         } else {
 800                 event->dev_db = udev_device_new(event->udev);
 801                 if (event->dev_db != NULL) {
 802                         udev_device_set_syspath(event->dev_db, udev_device_get_syspath(dev));
 803                         udev_device_set_subsystem(event->dev_db, udev_device_get_subsystem(dev));
 804                         udev_device_read_db(event->dev_db, NULL);
 805                         udev_device_set_info_loaded(event->dev_db);
 806
 807                         /* disable watch during event processing */
 808                         if (major(udev_device_get_devnum(dev)) != 0)
 809                                 udev_watch_end(event->udev, event->dev_db);
 810                 }
 811
 812                 udev_rules_apply_to_event(rules, event, sigmask);
 813
 814                 /* rename a new network interface, if needed */
 815                 if (udev_device_get_ifindex(dev) > 0 && strcmp(udev_device_get_action(dev), "add") == 0 &&
 816                     event->name != NULL && strcmp(event->name, udev_device_get_sysname(dev)) != 0) {
 817                         char syspath[UTIL_PATH_SIZE];
 818                         char *pos;
 819
 820                         err = rename_netif(event);
 821                         if (err == 0) {
 822                                 log_debug("renamed netif to '%s'\n", 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'\n", udev_device_get_devpath(dev));
 836                                 }
 837                         }
 838                 }
 839
 840                 if (major(udev_device_get_devnum(dev)) > 0) {
 841                         /* remove/update possible left-over symlinks from old database entry */
 842                         if (event->dev_db != NULL)
 843                                 udev_node_update_old_links(dev, event->dev_db);
 844
 845                         if (!event->owner_set)
 846                                 event->uid = udev_device_get_devnode_uid(dev);
 847
 848                         if (!event->group_set)
 849                                 event->gid = udev_device_get_devnode_gid(dev);
 850
 851                         if (!event->mode_set) {
 852                                 if (udev_device_get_devnode_mode(dev) > 0) {
 853                                         /* kernel supplied value */
 854                                         event->mode = udev_device_get_devnode_mode(dev);
 855                                 } else if (event->gid > 0) {
 856                                         /* default 0660 if a group is assigned */
 857                                         event->mode = 0660;
 858                                 } else {
 859                                         /* default 0600 */
 860                                         event->mode = 0600;
 861                                 }
 862                         }
 863
 864                         udev_node_add(dev, event->mode, event->uid, event->gid);
 865                 }
 866
 867                 /* preserve old, or get new initialization timestamp */
 868                 if (event->dev_db != NULL && udev_device_get_usec_initialized(event->dev_db) > 0)
 869                         udev_device_set_usec_initialized(event->dev, udev_device_get_usec_initialized(event->dev_db));
 870                 else if (udev_device_get_usec_initialized(event->dev) == 0)
 871                         udev_device_set_usec_initialized(event->dev, now(CLOCK_MONOTONIC));
 872
 873                 /* (re)write database file */
 874                 udev_device_update_db(dev);
 875                 udev_device_tag_index(dev, event->dev_db, true);
 876                 udev_device_set_is_initialized(dev);
 877
 878                 udev_device_unref(event->dev_db);
 879                 event->dev_db = NULL;
 880         }
 881         return err;
 882 }
 883
 884 void udev_event_execute_run(struct udev_event *event, const sigset_t *sigmask)
 885 {
 886         struct udev_list_entry *list_entry;
 887
 888         udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
 889                 const char *cmd = udev_list_entry_get_name(list_entry);
 890                 enum udev_builtin_cmd builtin_cmd = udev_list_entry_get_num(list_entry);
 891
 892                 if (builtin_cmd < UDEV_BUILTIN_MAX) {
 893                         char command[UTIL_PATH_SIZE];
 894
 895                         udev_event_apply_format(event, cmd, command, sizeof(command));
 896                         udev_builtin_run(event->dev, builtin_cmd, command, false);
 897                 } else {
 898                         char program[UTIL_PATH_SIZE];
 899                         char **envp;
 900
 901                         if (event->exec_delay > 0) {
 902                                 log_debug("delay execution of '%s'\n", program);
 903                                 sleep(event->exec_delay);
 904                         }
 905
 906                         udev_event_apply_format(event, cmd, program, sizeof(program));
 907                         envp = udev_device_get_properties_envp(event->dev);
 908                         udev_event_spawn(event, program, envp, sigmask, NULL, 0);
 909                 }
 910         }
 911 }