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         int err;
 380         int fd;
 381
 382         /* discard child output or connect to pipe */
 383         fd = open("/dev/null", O_RDWR);
 384         if (fd >= 0) {
 385                 dup2(fd, STDIN_FILENO);
 386                 if (fd_stdout < 0)
 387                         dup2(fd, STDOUT_FILENO);
 388                 if (fd_stderr < 0)
 389                         dup2(fd, STDERR_FILENO);
 390                 close(fd);
 391         } else {
 392                 log_error("open /dev/null failed: %m");
 393         }
 394
 395         /* connect pipes to std{out,err} */
 396         if (fd_stdout >= 0) {
 397                 dup2(fd_stdout, STDOUT_FILENO);
 398                         close(fd_stdout);
 399         }
 400         if (fd_stderr >= 0) {
 401                 dup2(fd_stderr, STDERR_FILENO);
 402                 close(fd_stderr);
 403         }
 404
 405         /* terminate child in case parent goes away */
 406         prctl(PR_SET_PDEATHSIG, SIGTERM);
 407
 408         /* restore original udev sigmask before exec */
 409         if (sigmask)
 410                 sigprocmask(SIG_SETMASK, sigmask, NULL);
 411
 412         execve(argv[0], argv, envp);
 413
 414         /* exec failed */
 415         err = -errno;
 416         log_error("failed to execute '%s' '%s': %m", argv[0], cmd);
 417         return err;
 418 }
 419
 420 static void spawn_read(struct udev_event *event,
 421                        usec_t timeout_usec,
 422                        const char *cmd,
 423                        int fd_stdout, int fd_stderr,
 424                        char *result, size_t ressize) {
 425         size_t respos = 0;
 426         int fd_ep = -1;
 427         struct epoll_event ep_outpipe, ep_errpipe;
 428
 429         /* read from child if requested */
 430         if (fd_stdout < 0 && fd_stderr < 0)
 431                 return;
 432
 433         fd_ep = epoll_create1(EPOLL_CLOEXEC);
 434         if (fd_ep < 0) {
 435                 log_error("error creating epoll fd: %m");
 436                 goto out;
 437         }
 438
 439         if (fd_stdout >= 0) {
 440                 memzero(&ep_outpipe, sizeof(struct epoll_event));
 441                 ep_outpipe.events = EPOLLIN;
 442                 ep_outpipe.data.ptr = &fd_stdout;
 443                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe) < 0) {
 444                         log_error("fail to add fd to epoll: %m");
 445                         goto out;
 446                 }
 447         }
 448
 449         if (fd_stderr >= 0) {
 450                 memzero(&ep_errpipe, sizeof(struct epoll_event));
 451                 ep_errpipe.events = EPOLLIN;
 452                 ep_errpipe.data.ptr = &fd_stderr;
 453                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe) < 0) {
 454                         log_error("fail to add fd to epoll: %m");
 455                         goto out;
 456                 }
 457         }
 458
 459         /* read child output */
 460         while (fd_stdout >= 0 || fd_stderr >= 0) {
 461                 int timeout;
 462                 int fdcount;
 463                 struct epoll_event ev[4];
 464                 int i;
 465
 466                 if (timeout_usec > 0) {
 467                         usec_t age_usec;
 468
 469                         age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
 470                         if (age_usec >= timeout_usec) {
 471                                 log_error("timeout '%s'", cmd);
 472                                 goto out;
 473                         }
 474                         timeout = ((timeout_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
 475                 } else {
 476                         timeout = -1;
 477                 }
 478
 479                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
 480                 if (fdcount < 0) {
 481                         if (errno == EINTR)
 482                                 continue;
 483                         log_error("failed to poll: %m");
 484                         goto out;
 485                 }
 486                 if (fdcount == 0) {
 487                         log_error("timeout '%s'", cmd);
 488                         goto out;
 489                 }
 490
 491                 for (i = 0; i < fdcount; i++) {
 492                         int *fd = (int *)ev[i].data.ptr;
 493
 494                         if (ev[i].events & EPOLLIN) {
 495                                 ssize_t count;
 496                                 char buf[4096];
 497
 498                                 count = read(*fd, buf, sizeof(buf)-1);
 499                                 if (count <= 0)
 500                                         continue;
 501                                 buf[count] = '\0';
 502
 503                                 /* store stdout result */
 504                                 if (result != NULL && *fd == fd_stdout) {
 505                                         if (respos + count < ressize) {
 506                                                 memcpy(&result[respos], buf, count);
 507                                                 respos += count;
 508                                         } else {
 509                                                 log_error("'%s' ressize %zd too short", cmd, ressize);
 510                                         }
 511                                 }
 512
 513                                 /* log debug output only if we watch stderr */
 514                                 if (fd_stderr >= 0) {
 515                                         char *pos;
 516                                         char *line;
 517
 518                                         pos = buf;
 519                                         while ((line = strsep(&pos, "\n"))) {
 520                                                 if (pos != NULL || line[0] != '\0')
 521                                                         log_debug("'%s'(%s) '%s'", cmd, *fd == fd_stdout ? "out" : "err" , line);
 522                                         }
 523                                 }
 524                         } else if (ev[i].events & EPOLLHUP) {
 525                                 if (epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL) < 0) {
 526                                         log_error("failed to remove fd from epoll: %m");
 527                                         goto out;
 528                                 }
 529                                 *fd = -1;
 530                         }
 531                 }
 532         }
 533
 534         /* return the child's stdout string */
 535         if (result != NULL)
 536                 result[respos] = '\0';
 537 out:
 538         if (fd_ep >= 0)
 539                 close(fd_ep);
 540 }
 541
 542 static int spawn_wait(struct udev_event *event,
 543                       usec_t timeout_usec,
 544                       const char *cmd, pid_t pid) {
 545         struct pollfd pfd[1];
 546         int err = 0;
 547
 548         pfd[0].events = POLLIN;
 549         pfd[0].fd = event->fd_signal;
 550
 551         while (pid > 0) {
 552                 int timeout;
 553                 int fdcount;
 554
 555                 if (timeout_usec > 0) {
 556                         usec_t age_usec;
 557
 558                         age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
 559                         if (age_usec >= timeout_usec)
 560                                 timeout = 1000;
 561                         else
 562                                 timeout = ((timeout_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
 563                 } else {
 564                         timeout = -1;
 565                 }
 566
 567                 fdcount = poll(pfd, 1, timeout);
 568                 if (fdcount < 0) {
 569                         if (errno == EINTR)
 570                                 continue;
 571                         err = -errno;
 572                         log_error("failed to poll: %m");
 573                         goto out;
 574                 }
 575                 if (fdcount == 0) {
 576                         log_error("timeout: killing '%s' [%u]", cmd, pid);
 577                         kill(pid, SIGKILL);
 578                 }
 579
 580                 if (pfd[0].revents & POLLIN) {
 581                         struct signalfd_siginfo fdsi;
 582                         int status;
 583                         ssize_t size;
 584
 585                         size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 586                         if (size != sizeof(struct signalfd_siginfo))
 587                                 continue;
 588
 589                         switch (fdsi.ssi_signo) {
 590                         case SIGTERM:
 591                                 event->sigterm = true;
 592                                 break;
 593                         case SIGCHLD:
 594                                 if (waitpid(pid, &status, WNOHANG) < 0)
 595                                         break;
 596                                 if (WIFEXITED(status)) {
 597                                         log_debug("'%s' [%u] exit with return code %i", cmd, pid, WEXITSTATUS(status));
 598                                         if (WEXITSTATUS(status) != 0)
 599                                                 err = -1;
 600                                 } else if (WIFSIGNALED(status)) {
 601                                         log_error("'%s' [%u] terminated by signal %i (%s)", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 602                                         err = -1;
 603                                 } else if (WIFSTOPPED(status)) {
 604                                         log_error("'%s' [%u] stopped", cmd, pid);
 605                                         err = -1;
 606                                 } else if (WIFCONTINUED(status)) {
 607                                         log_error("'%s' [%u] continued", cmd, pid);
 608                                         err = -1;
 609                                 } else {
 610                                         log_error("'%s' [%u] exit with status 0x%04x", cmd, pid, status);
 611                                         err = -1;
 612                                 }
 613                                 pid = 0;
 614                                 break;
 615                         }
 616                 }
 617         }
 618 out:
 619         return err;
 620 }
 621
 622 int udev_build_argv(struct udev *udev, char *cmd, int *argc, char *argv[]) {
 623         int i = 0;
 624         char *pos;
 625
 626         if (strchr(cmd, ' ') == NULL) {
 627                 argv[i++] = cmd;
 628                 goto out;
 629         }
 630
 631         pos = cmd;
 632         while (pos != NULL && pos[0] != '\0') {
 633                 if (pos[0] == '\'') {
 634                         /* do not separate quotes */
 635                         pos++;
 636                         argv[i] = strsep(&pos, "\'");
 637                         if (pos != NULL)
 638                                 while (pos[0] == ' ')
 639                                         pos++;
 640                 } else {
 641                         argv[i] = strsep(&pos, " ");
 642                         if (pos != NULL)
 643                                 while (pos[0] == ' ')
 644                                         pos++;
 645                 }
 646                 i++;
 647         }
 648 out:
 649         argv[i] = NULL;
 650         if (argc)
 651                 *argc = i;
 652         return 0;
 653 }
 654
 655 int udev_event_spawn(struct udev_event *event,
 656                      usec_t timeout_usec,
 657                      const char *cmd, char **envp, const sigset_t *sigmask,
 658                      char *result, size_t ressize) {
 659         struct udev *udev = event->udev;
 660         int outpipe[2] = {-1, -1};
 661         int errpipe[2] = {-1, -1};
 662         pid_t pid;
 663         char arg[UTIL_PATH_SIZE];
 664         char *argv[128];
 665         char program[UTIL_PATH_SIZE];
 666         int err = 0;
 667
 668         strscpy(arg, sizeof(arg), cmd);
 669         udev_build_argv(event->udev, arg, NULL, argv);
 670
 671         /* pipes from child to parent */
 672         if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
 673                 if (pipe2(outpipe, O_NONBLOCK) != 0) {
 674                         err = -errno;
 675                         log_error("pipe failed: %m");
 676                         goto out;
 677                 }
 678         }
 679         if (udev_get_log_priority(udev) >= LOG_INFO) {
 680                 if (pipe2(errpipe, O_NONBLOCK) != 0) {
 681                         err = -errno;
 682                         log_error("pipe failed: %m");
 683                         goto out;
 684                 }
 685         }
 686
 687         /* allow programs in /usr/lib/udev/ to be called without the path */
 688         if (argv[0][0] != '/') {
 689                 strscpyl(program, sizeof(program), UDEVLIBEXECDIR "/", argv[0], NULL);
 690                 argv[0] = program;
 691         }
 692
 693         pid = fork();
 694         switch(pid) {
 695         case 0:
 696                 /* child closes parent's ends of pipes */
 697                 if (outpipe[READ_END] >= 0) {
 698                         close(outpipe[READ_END]);
 699                         outpipe[READ_END] = -1;
 700                 }
 701                 if (errpipe[READ_END] >= 0) {
 702                         close(errpipe[READ_END]);
 703                         errpipe[READ_END] = -1;
 704                 }
 705
 706                 log_debug("starting '%s'", cmd);
 707
 708                 spawn_exec(event, cmd, argv, envp, sigmask,
 709                            outpipe[WRITE_END], errpipe[WRITE_END]);
 710
 711                 _exit(2 );
 712         case -1:
 713                 log_error("fork of '%s' failed: %m", cmd);
 714                 err = -1;
 715                 goto out;
 716         default:
 717                 /* parent closed child's ends of pipes */
 718                 if (outpipe[WRITE_END] >= 0) {
 719                         close(outpipe[WRITE_END]);
 720                         outpipe[WRITE_END] = -1;
 721                 }
 722                 if (errpipe[WRITE_END] >= 0) {
 723                         close(errpipe[WRITE_END]);
 724                         errpipe[WRITE_END] = -1;
 725                 }
 726
 727                 spawn_read(event,
 728                            timeout_usec,
 729                            cmd,
 730                            outpipe[READ_END], errpipe[READ_END],
 731                            result, ressize);
 732
 733                 err = spawn_wait(event, timeout_usec, 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         struct udev_device *dev = event->dev;
 750         char name[IFNAMSIZ];
 751         const char *oldname;
 752         int r;
 753
 754         oldname = udev_device_get_sysname(dev);
 755
 756         strscpy(name, IFNAMSIZ, event->name);
 757
 758         r = rtnl_set_link_name(&event->rtnl, udev_device_get_ifindex(dev), name);
 759         if (r < 0) {
 760                 log_error("error changing net interface name '%s' to '%s': %s",
 761                           oldname, name, strerror(-r));
 762                 return r;
 763         }
 764
 765         print_kmsg("renamed network interface '%s' to '%s'\n", oldname, name);
 766
 767         return 0;
 768 }
 769
 770 void udev_event_execute_rules(struct udev_event *event,
 771                               usec_t timeout_usec,
 772                               struct udev_rules *rules, const sigset_t *sigmask) {
 773         struct udev_device *dev = event->dev;
 774
 775         if (udev_device_get_subsystem(dev) == NULL)
 776                 return;
 777
 778         if (streq(udev_device_get_action(dev), "remove")) {
 779                 udev_device_read_db(dev, NULL);
 780                 udev_device_delete_db(dev);
 781                 udev_device_tag_index(dev, NULL, false);
 782
 783                 if (major(udev_device_get_devnum(dev)) != 0)
 784                         udev_watch_end(event->udev, dev);
 785
 786                 udev_rules_apply_to_event(rules, event, timeout_usec, sigmask);
 787
 788                 if (major(udev_device_get_devnum(dev)) != 0)
 789                         udev_node_remove(dev);
 790         } else {
 791                 event->dev_db = udev_device_new(event->udev);
 792                 if (event->dev_db != NULL) {
 793                         udev_device_set_syspath(event->dev_db, udev_device_get_syspath(dev));
 794                         udev_device_set_subsystem(event->dev_db, udev_device_get_subsystem(dev));
 795                         udev_device_read_db(event->dev_db, NULL);
 796                         udev_device_set_info_loaded(event->dev_db);
 797
 798                         /* disable watch during event processing */
 799                         if (major(udev_device_get_devnum(dev)) != 0)
 800                                 udev_watch_end(event->udev, event->dev_db);
 801                 }
 802
 803                 if (major(udev_device_get_devnum(dev)) == 0 &&
 804                     streq(udev_device_get_action(dev), "move")) {
 805                         struct udev_list_entry *entry;
 806
 807                         for ((entry = udev_device_get_properties_list_entry(event->dev_db)); entry; entry = udev_list_entry_get_next(entry)) {
 808                                 const char *key, *value;
 809                                 struct udev_list_entry *property;
 810
 811                                 key = udev_list_entry_get_name(entry);
 812                                 value = udev_list_entry_get_value(entry);
 813
 814                                 property = udev_device_add_property(event->dev, key, value);
 815                                 udev_list_entry_set_num(property, true);
 816                         }
 817                 }
 818
 819                 udev_rules_apply_to_event(rules, event, timeout_usec, sigmask);
 820
 821                 /* rename a new network interface, if needed */
 822                 if (udev_device_get_ifindex(dev) > 0 && streq(udev_device_get_action(dev), "add") &&
 823                     event->name != NULL && !streq(event->name, udev_device_get_sysname(dev))) {
 824                         char syspath[UTIL_PATH_SIZE];
 825                         char *pos;
 826                         int r;
 827
 828                         r = rename_netif(event);
 829                         if (r >= 0) {
 830                                 /* remember old name */
 831                                 udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
 832
 833                                 /* now change the devpath, because the kernel device name has changed */
 834                                 strscpy(syspath, sizeof(syspath), udev_device_get_syspath(dev));
 835                                 pos = strrchr(syspath, '/');
 836                                 if (pos != NULL) {
 837                                         pos++;
 838                                         strscpy(pos, sizeof(syspath) - (pos - syspath), event->name);
 839                                         udev_device_set_syspath(event->dev, syspath);
 840                                         udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
 841                                         log_debug("changed devpath to '%s'", udev_device_get_devpath(dev));
 842                                 }
 843                         }
 844                 }
 845
 846                 if (major(udev_device_get_devnum(dev)) > 0) {
 847                         bool apply;
 848
 849                         /* remove/update possible left-over symlinks from old database entry */
 850                         if (event->dev_db != NULL)
 851                                 udev_node_update_old_links(dev, event->dev_db);
 852
 853                         if (!event->owner_set)
 854                                 event->uid = udev_device_get_devnode_uid(dev);
 855
 856                         if (!event->group_set)
 857                                 event->gid = udev_device_get_devnode_gid(dev);
 858
 859                         if (!event->mode_set) {
 860                                 if (udev_device_get_devnode_mode(dev) > 0) {
 861                                         /* kernel supplied value */
 862                                         event->mode = udev_device_get_devnode_mode(dev);
 863                                 } else if (event->gid > 0) {
 864                                         /* default 0660 if a group is assigned */
 865                                         event->mode = 0660;
 866                                 } else {
 867                                         /* default 0600 */
 868                                         event->mode = 0600;
 869                                 }
 870                         }
 871
 872                         apply = streq(udev_device_get_action(dev), "add") || event->owner_set || event->group_set || event->mode_set;
 873                         udev_node_add(dev, apply, event->mode, event->uid, event->gid, &event->seclabel_list);
 874                 }
 875
 876                 /* preserve old, or get new initialization timestamp */
 877                 if (event->dev_db != NULL && udev_device_get_usec_initialized(event->dev_db) > 0)
 878                         udev_device_set_usec_initialized(event->dev, udev_device_get_usec_initialized(event->dev_db));
 879                 else if (udev_device_get_usec_initialized(event->dev) == 0)
 880                         udev_device_set_usec_initialized(event->dev, now(CLOCK_MONOTONIC));
 881
 882                 /* (re)write database file */
 883                 udev_device_update_db(dev);
 884                 udev_device_tag_index(dev, event->dev_db, true);
 885                 udev_device_set_is_initialized(dev);
 886
 887                 udev_device_unref(event->dev_db);
 888                 event->dev_db = NULL;
 889         }
 890 }
 891
 892 void udev_event_execute_run(struct udev_event *event, usec_t timeout_usec, const sigset_t *sigmask) {
 893         struct udev_list_entry *list_entry;
 894
 895         udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
 896                 const char *cmd = udev_list_entry_get_name(list_entry);
 897                 enum udev_builtin_cmd builtin_cmd = udev_list_entry_get_num(list_entry);
 898
 899                 if (builtin_cmd < UDEV_BUILTIN_MAX) {
 900                         char command[UTIL_PATH_SIZE];
 901
 902                         udev_event_apply_format(event, cmd, command, sizeof(command));
 903                         udev_builtin_run(event->dev, builtin_cmd, command, false);
 904                 } else {
 905                         char program[UTIL_PATH_SIZE];
 906                         char **envp;
 907
 908                         if (event->exec_delay > 0) {
 909                                 log_debug("delay execution of '%s'", program);
 910                                 sleep(event->exec_delay);
 911                         }
 912
 913                         udev_event_apply_format(event, cmd, program, sizeof(program));
 914                         envp = udev_device_get_properties_envp(event->dev);
 915                         udev_event_spawn(event, timeout_usec, program, envp, sigmask, NULL, 0);
 916                 }
 917         }
 918 }