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         return event;
  52 }
  53
  54 void udev_event_unref(struct udev_event *event)
  55 {
  56         if (event == NULL)
  57                 return;
  58         udev_list_cleanup(&event->run_list);
  59         udev_list_cleanup(&event->seclabel_list);
  60         free(event->program_result);
  61         free(event->name);
  62         free(event);
  63 }
  64
  65 size_t udev_event_apply_format(struct udev_event *event, const char *src, char *dest, size_t size)
  66 {
  67         struct udev_device *dev = event->dev;
  68         enum subst_type {
  69                 SUBST_UNKNOWN,
  70                 SUBST_DEVNODE,
  71                 SUBST_ATTR,
  72                 SUBST_ENV,
  73                 SUBST_KERNEL,
  74                 SUBST_KERNEL_NUMBER,
  75                 SUBST_DRIVER,
  76                 SUBST_DEVPATH,
  77                 SUBST_ID,
  78                 SUBST_MAJOR,
  79                 SUBST_MINOR,
  80                 SUBST_RESULT,
  81                 SUBST_PARENT,
  82                 SUBST_NAME,
  83                 SUBST_LINKS,
  84                 SUBST_ROOT,
  85                 SUBST_SYS,
  86         };
  87         static const struct subst_map {
  88                 const char *name;
  89                 const char fmt;
  90                 enum subst_type type;
  91         } map[] = {
  92                 { .name = "devnode",  .fmt = 'N', .type = SUBST_DEVNODE },
  93                 { .name = "tempnode", .fmt = 'N', .type = SUBST_DEVNODE },
  94                 { .name = "attr",     .fmt = 's', .type = SUBST_ATTR },
  95                 { .name = "sysfs",    .fmt = 's', .type = SUBST_ATTR },
  96                 { .name = "env",      .fmt = 'E', .type = SUBST_ENV },
  97                 { .name = "kernel",   .fmt = 'k', .type = SUBST_KERNEL },
  98                 { .name = "number",   .fmt = 'n', .type = SUBST_KERNEL_NUMBER },
  99                 { .name = "driver",   .fmt = 'd', .type = SUBST_DRIVER },
 100                 { .name = "devpath",  .fmt = 'p', .type = SUBST_DEVPATH },
 101                 { .name = "id",       .fmt = 'b', .type = SUBST_ID },
 102                 { .name = "major",    .fmt = 'M', .type = SUBST_MAJOR },
 103                 { .name = "minor",    .fmt = 'm', .type = SUBST_MINOR },
 104                 { .name = "result",   .fmt = 'c', .type = SUBST_RESULT },
 105                 { .name = "parent",   .fmt = 'P', .type = SUBST_PARENT },
 106                 { .name = "name",     .fmt = 'D', .type = SUBST_NAME },
 107                 { .name = "links",    .fmt = 'L', .type = SUBST_LINKS },
 108                 { .name = "root",     .fmt = 'r', .type = SUBST_ROOT },
 109                 { .name = "sys",      .fmt = 'S', .type = SUBST_SYS },
 110         };
 111         const char *from;
 112         char *s;
 113         size_t l;
 114
 115         from = src;
 116         s = dest;
 117         l = size;
 118
 119         for (;;) {
 120                 enum subst_type type = SUBST_UNKNOWN;
 121                 char attrbuf[UTIL_PATH_SIZE];
 122                 char *attr = NULL;
 123
 124                 while (from[0] != '\0') {
 125                         if (from[0] == '$') {
 126                                 /* substitute named variable */
 127                                 unsigned int i;
 128
 129                                 if (from[1] == '$') {
 130                                         from++;
 131                                         goto copy;
 132                                 }
 133
 134                                 for (i = 0; i < ELEMENTSOF(map); i++) {
 135                                         if (startswith(&from[1], map[i].name)) {
 136                                                 type = map[i].type;
 137                                                 from += strlen(map[i].name)+1;
 138                                                 goto subst;
 139                                         }
 140                                 }
 141                         } else if (from[0] == '%') {
 142                                 /* substitute format char */
 143                                 unsigned int i;
 144
 145                                 if (from[1] == '%') {
 146                                         from++;
 147                                         goto copy;
 148                                 }
 149
 150                                 for (i = 0; i < ELEMENTSOF(map); i++) {
 151                                         if (from[1] == map[i].fmt) {
 152                                                 type = map[i].type;
 153                                                 from += 2;
 154                                                 goto subst;
 155                                         }
 156                                 }
 157                         }
 158 copy:
 159                         /* copy char */
 160                         if (l == 0)
 161                                 goto out;
 162                         s[0] = from[0];
 163                         from++;
 164                         s++;
 165                         l--;
 166                 }
 167
 168                 goto out;
 169 subst:
 170                 /* extract possible $format{attr} */
 171                 if (from[0] == '{') {
 172                         unsigned int i;
 173
 174                         from++;
 175                         for (i = 0; from[i] != '}'; i++) {
 176                                 if (from[i] == '\0') {
 177                                         log_error("missing closing brace for format '%s'", src);
 178                                         goto out;
 179                                 }
 180                         }
 181                         if (i >= sizeof(attrbuf))
 182                                 goto out;
 183                         memcpy(attrbuf, from, i);
 184                         attrbuf[i] = '\0';
 185                         from += i+1;
 186                         attr = attrbuf;
 187                 } else {
 188                         attr = NULL;
 189                 }
 190
 191                 switch (type) {
 192                 case SUBST_DEVPATH:
 193                         l = strpcpy(&s, l, udev_device_get_devpath(dev));
 194                         break;
 195                 case SUBST_KERNEL:
 196                         l = strpcpy(&s, l, udev_device_get_sysname(dev));
 197                         break;
 198                 case SUBST_KERNEL_NUMBER:
 199                         if (udev_device_get_sysnum(dev) == NULL)
 200                                 break;
 201                         l = strpcpy(&s, l, udev_device_get_sysnum(dev));
 202                         break;
 203                 case SUBST_ID:
 204                         if (event->dev_parent == NULL)
 205                                 break;
 206                         l = strpcpy(&s, l, udev_device_get_sysname(event->dev_parent));
 207                         break;
 208                 case SUBST_DRIVER: {
 209                         const char *driver;
 210
 211                         if (event->dev_parent == NULL)
 212                                 break;
 213
 214                         driver = udev_device_get_driver(event->dev_parent);
 215                         if (driver == NULL)
 216                                 break;
 217                         l = strpcpy(&s, l, driver);
 218                         break;
 219                 }
 220                 case SUBST_MAJOR: {
 221                         char num[UTIL_PATH_SIZE];
 222
 223                         sprintf(num, "%d", major(udev_device_get_devnum(dev)));
 224                         l = strpcpy(&s, l, num);
 225                         break;
 226                 }
 227                 case SUBST_MINOR: {
 228                         char num[UTIL_PATH_SIZE];
 229
 230                         sprintf(num, "%d", minor(udev_device_get_devnum(dev)));
 231                         l = strpcpy(&s, l, num);
 232                         break;
 233                 }
 234                 case SUBST_RESULT: {
 235                         char *rest;
 236                         int i;
 237
 238                         if (event->program_result == NULL)
 239                                 break;
 240                         /* get part part of the result string */
 241                         i = 0;
 242                         if (attr != NULL)
 243                                 i = strtoul(attr, &rest, 10);
 244                         if (i > 0) {
 245                                 char result[UTIL_PATH_SIZE];
 246                                 char tmp[UTIL_PATH_SIZE];
 247                                 char *cpos;
 248
 249                                 strscpy(result, sizeof(result), event->program_result);
 250                                 cpos = result;
 251                                 while (--i) {
 252                                         while (cpos[0] != '\0' && !isspace(cpos[0]))
 253                                                 cpos++;
 254                                         while (isspace(cpos[0]))
 255                                                 cpos++;
 256                                         if (cpos[0] == '\0')
 257                                                 break;
 258                                 }
 259                                 if (i > 0) {
 260                                         log_error("requested part of result string not found");
 261                                         break;
 262                                 }
 263                                 strscpy(tmp, sizeof(tmp), cpos);
 264                                 /* %{2+}c copies the whole string from the second part on */
 265                                 if (rest[0] != '+') {
 266                                         cpos = strchr(tmp, ' ');
 267                                         if (cpos)
 268                                                 cpos[0] = '\0';
 269                                 }
 270                                 l = strpcpy(&s, l, tmp);
 271                         } else {
 272                                 l = strpcpy(&s, l, event->program_result);
 273                         }
 274                         break;
 275                 }
 276                 case SUBST_ATTR: {
 277                         const char *value = NULL;
 278                         char vbuf[UTIL_NAME_SIZE];
 279                         size_t len;
 280                         int count;
 281
 282                         if (attr == NULL) {
 283                                 log_error("missing file parameter for attr");
 284                                 break;
 285                         }
 286
 287                         /* try to read the value specified by "[dmi/id]product_name" */
 288                         if (util_resolve_subsys_kernel(event->udev, attr, vbuf, sizeof(vbuf), 1) == 0)
 289                                 value = vbuf;
 290
 291                         /* try to read the attribute the device */
 292                         if (value == NULL)
 293                                 value = udev_device_get_sysattr_value(event->dev, attr);
 294
 295                         /* try to read the attribute of the parent device, other matches have selected */
 296                         if (value == NULL && event->dev_parent != NULL && event->dev_parent != event->dev)
 297                                 value = udev_device_get_sysattr_value(event->dev_parent, attr);
 298
 299                         if (value == NULL)
 300                                 break;
 301
 302                         /* strip trailing whitespace, and replace unwanted characters */
 303                         if (value != vbuf)
 304                                 strscpy(vbuf, sizeof(vbuf), value);
 305                         len = strlen(vbuf);
 306                         while (len > 0 && isspace(vbuf[--len]))
 307                                 vbuf[len] = '\0';
 308                         count = util_replace_chars(vbuf, UDEV_ALLOWED_CHARS_INPUT);
 309                         if (count > 0)
 310                                 log_debug("%i character(s) replaced" , count);
 311                         l = strpcpy(&s, l, vbuf);
 312                         break;
 313                 }
 314                 case SUBST_PARENT: {
 315                         struct udev_device *dev_parent;
 316                         const char *devnode;
 317
 318                         dev_parent = udev_device_get_parent(event->dev);
 319                         if (dev_parent == NULL)
 320                                 break;
 321                         devnode = udev_device_get_devnode(dev_parent);
 322                         if (devnode != NULL)
 323                                 l = strpcpy(&s, l, devnode + strlen("/dev/"));
 324                         break;
 325                 }
 326                 case SUBST_DEVNODE:
 327                         if (udev_device_get_devnode(dev) != NULL)
 328                                 l = strpcpy(&s, l, udev_device_get_devnode(dev));
 329                         break;
 330                 case SUBST_NAME:
 331                         if (event->name != NULL)
 332                                 l = strpcpy(&s, l, event->name);
 333                         else if (udev_device_get_devnode(dev) != NULL)
 334                                 l = strpcpy(&s, l, udev_device_get_devnode(dev) + strlen("/dev/"));
 335                         else
 336                                 l = strpcpy(&s, l, udev_device_get_sysname(dev));
 337                         break;
 338                 case SUBST_LINKS: {
 339                         struct udev_list_entry *list_entry;
 340
 341                         list_entry = udev_device_get_devlinks_list_entry(dev);
 342                         if (list_entry == NULL)
 343                                 break;
 344                         l = strpcpy(&s, l, udev_list_entry_get_name(list_entry) + strlen("/dev/"));
 345                         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
 346                                 l = strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry) + strlen("/dev/"), NULL);
 347                         break;
 348                 }
 349                 case SUBST_ROOT:
 350                         l = strpcpy(&s, l, "/dev");
 351                         break;
 352                 case SUBST_SYS:
 353                         l = strpcpy(&s, l, "/sys");
 354                         break;
 355                 case SUBST_ENV:
 356                         if (attr == NULL) {
 357                                 break;
 358                         } else {
 359                                 const char *value;
 360
 361                                 value = udev_device_get_property_value(event->dev, attr);
 362                                 if (value == NULL)
 363                                         break;
 364                                 l = strpcpy(&s, l, value);
 365                                 break;
 366                         }
 367                 default:
 368                         log_error("unknown substitution type=%i", type);
 369                         break;
 370                 }
 371         }
 372
 373 out:
 374         s[0] = '\0';
 375         return l;
 376 }
 377
 378 static int spawn_exec(struct udev_event *event,
 379                       const char *cmd, char *const argv[], char **envp, const sigset_t *sigmask,
 380                       int fd_stdout, int fd_stderr)
 381 {
 382         int err;
 383         int fd;
 384
 385         /* discard child output or connect to pipe */
 386         fd = open("/dev/null", O_RDWR);
 387         if (fd >= 0) {
 388                 dup2(fd, STDIN_FILENO);
 389                 if (fd_stdout < 0)
 390                         dup2(fd, STDOUT_FILENO);
 391                 if (fd_stderr < 0)
 392                         dup2(fd, STDERR_FILENO);
 393                 close(fd);
 394         } else {
 395                 log_error("open /dev/null failed: %m");
 396         }
 397
 398         /* connect pipes to std{out,err} */
 399         if (fd_stdout >= 0) {
 400                 dup2(fd_stdout, STDOUT_FILENO);
 401                         close(fd_stdout);
 402         }
 403         if (fd_stderr >= 0) {
 404                 dup2(fd_stderr, STDERR_FILENO);
 405                 close(fd_stderr);
 406         }
 407
 408         /* terminate child in case parent goes away */
 409         prctl(PR_SET_PDEATHSIG, SIGTERM);
 410
 411         /* restore original udev sigmask before exec */
 412         if (sigmask)
 413                 sigprocmask(SIG_SETMASK, sigmask, NULL);
 414
 415         execve(argv[0], argv, envp);
 416
 417         /* exec failed */
 418         err = -errno;
 419         log_error("failed to execute '%s' '%s': %m", argv[0], cmd);
 420         return err;
 421 }
 422
 423 static void spawn_read(struct udev_event *event,
 424                        usec_t timeout_usec,
 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 (timeout_usec > 0) {
 471                         usec_t age_usec;
 472
 473                         age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
 474                         if (age_usec >= timeout_usec) {
 475                                 log_error("timeout '%s'", cmd);
 476                                 goto out;
 477                         }
 478                         timeout = ((timeout_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
 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,
 547                       usec_t timeout_usec,
 548                       const char *cmd, pid_t pid) {
 549         struct pollfd pfd[1];
 550         int err = 0;
 551
 552         pfd[0].events = POLLIN;
 553         pfd[0].fd = event->fd_signal;
 554
 555         while (pid > 0) {
 556                 int timeout;
 557                 int fdcount;
 558
 559                 if (timeout_usec > 0) {
 560                         usec_t age_usec;
 561
 562                         age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
 563                         if (age_usec >= timeout_usec)
 564                                 timeout = 1000;
 565                         else
 566                                 timeout = ((timeout_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
 567                 } else {
 568                         timeout = -1;
 569                 }
 570
 571                 fdcount = poll(pfd, 1, timeout);
 572                 if (fdcount < 0) {
 573                         if (errno == EINTR)
 574                                 continue;
 575                         err = -errno;
 576                         log_error("failed to poll: %m");
 577                         goto out;
 578                 }
 579                 if (fdcount == 0) {
 580                         log_error("timeout: killing '%s' [%u]", cmd, pid);
 581                         kill(pid, SIGKILL);
 582                 }
 583
 584                 if (pfd[0].revents & POLLIN) {
 585                         struct signalfd_siginfo fdsi;
 586                         int status;
 587                         ssize_t size;
 588
 589                         size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 590                         if (size != sizeof(struct signalfd_siginfo))
 591                                 continue;
 592
 593                         switch (fdsi.ssi_signo) {
 594                         case SIGTERM:
 595                                 event->sigterm = true;
 596                                 break;
 597                         case SIGCHLD:
 598                                 if (waitpid(pid, &status, WNOHANG) < 0)
 599                                         break;
 600                                 if (WIFEXITED(status)) {
 601                                         log_debug("'%s' [%u] exit with return code %i", cmd, pid, WEXITSTATUS(status));
 602                                         if (WEXITSTATUS(status) != 0)
 603                                                 err = -1;
 604                                 } else if (WIFSIGNALED(status)) {
 605                                         log_error("'%s' [%u] terminated by signal %i (%s)", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 606                                         err = -1;
 607                                 } else if (WIFSTOPPED(status)) {
 608                                         log_error("'%s' [%u] stopped", cmd, pid);
 609                                         err = -1;
 610                                 } else if (WIFCONTINUED(status)) {
 611                                         log_error("'%s' [%u] continued", cmd, pid);
 612                                         err = -1;
 613                                 } else {
 614                                         log_error("'%s' [%u] exit with status 0x%04x", cmd, pid, status);
 615                                         err = -1;
 616                                 }
 617                                 pid = 0;
 618                                 break;
 619                         }
 620                 }
 621         }
 622 out:
 623         return err;
 624 }
 625
 626 int udev_build_argv(struct udev *udev, char *cmd, int *argc, char *argv[])
 627 {
 628         int i = 0;
 629         char *pos;
 630
 631         if (strchr(cmd, ' ') == NULL) {
 632                 argv[i++] = cmd;
 633                 goto out;
 634         }
 635
 636         pos = cmd;
 637         while (pos != NULL && pos[0] != '\0') {
 638                 if (pos[0] == '\'') {
 639                         /* do not separate quotes */
 640                         pos++;
 641                         argv[i] = strsep(&pos, "\'");
 642                         if (pos != NULL)
 643                                 while (pos[0] == ' ')
 644                                         pos++;
 645                 } else {
 646                         argv[i] = strsep(&pos, " ");
 647                         if (pos != NULL)
 648                                 while (pos[0] == ' ')
 649                                         pos++;
 650                 }
 651                 i++;
 652         }
 653 out:
 654         argv[i] = NULL;
 655         if (argc)
 656                 *argc = i;
 657         return 0;
 658 }
 659
 660 int udev_event_spawn(struct udev_event *event,
 661                      usec_t timeout_usec,
 662                      const char *cmd, char **envp, const sigset_t *sigmask,
 663                      char *result, size_t ressize) {
 664         struct udev *udev = event->udev;
 665         int outpipe[2] = {-1, -1};
 666         int errpipe[2] = {-1, -1};
 667         pid_t pid;
 668         char arg[UTIL_PATH_SIZE];
 669         char *argv[128];
 670         char program[UTIL_PATH_SIZE];
 671         int err = 0;
 672
 673         strscpy(arg, sizeof(arg), cmd);
 674         udev_build_argv(event->udev, arg, NULL, argv);
 675
 676         /* pipes from child to parent */
 677         if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
 678                 if (pipe2(outpipe, O_NONBLOCK) != 0) {
 679                         err = -errno;
 680                         log_error("pipe failed: %m");
 681                         goto out;
 682                 }
 683         }
 684         if (udev_get_log_priority(udev) >= LOG_INFO) {
 685                 if (pipe2(errpipe, O_NONBLOCK) != 0) {
 686                         err = -errno;
 687                         log_error("pipe failed: %m");
 688                         goto out;
 689                 }
 690         }
 691
 692         /* allow programs in /usr/lib/udev/ to be called without the path */
 693         if (argv[0][0] != '/') {
 694                 strscpyl(program, sizeof(program), UDEVLIBEXECDIR "/", argv[0], NULL);
 695                 argv[0] = program;
 696         }
 697
 698         pid = fork();
 699         switch(pid) {
 700         case 0:
 701                 /* child closes parent's ends of pipes */
 702                 if (outpipe[READ_END] >= 0) {
 703                         close(outpipe[READ_END]);
 704                         outpipe[READ_END] = -1;
 705                 }
 706                 if (errpipe[READ_END] >= 0) {
 707                         close(errpipe[READ_END]);
 708                         errpipe[READ_END] = -1;
 709                 }
 710
 711                 log_debug("starting '%s'", cmd);
 712
 713                 spawn_exec(event, cmd, argv, envp, sigmask,
 714                            outpipe[WRITE_END], errpipe[WRITE_END]);
 715
 716                 _exit(2 );
 717         case -1:
 718                 log_error("fork of '%s' failed: %m", cmd);
 719                 err = -1;
 720                 goto out;
 721         default:
 722                 /* parent closed child's ends of pipes */
 723                 if (outpipe[WRITE_END] >= 0) {
 724                         close(outpipe[WRITE_END]);
 725                         outpipe[WRITE_END] = -1;
 726                 }
 727                 if (errpipe[WRITE_END] >= 0) {
 728                         close(errpipe[WRITE_END]);
 729                         errpipe[WRITE_END] = -1;
 730                 }
 731
 732                 spawn_read(event,
 733                            timeout_usec,
 734                            cmd,
 735                            outpipe[READ_END], errpipe[READ_END],
 736                            result, ressize);
 737
 738                 err = spawn_wait(event, timeout_usec, cmd, pid);
 739         }
 740
 741 out:
 742         if (outpipe[READ_END] >= 0)
 743                 close(outpipe[READ_END]);
 744         if (outpipe[WRITE_END] >= 0)
 745                 close(outpipe[WRITE_END]);
 746         if (errpipe[READ_END] >= 0)
 747                 close(errpipe[READ_END]);
 748         if (errpipe[WRITE_END] >= 0)
 749                 close(errpipe[WRITE_END]);
 750         return err;
 751 }
 752
 753 static int rename_netif(struct udev_event *event)
 754 {
 755         struct udev_device *dev = event->dev;
 756         _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
 757         char name[IFNAMSIZ];
 758         const char *oldname;
 759         int r;
 760
 761         oldname = udev_device_get_sysname(dev);
 762
 763         log_debug("changing net interface name from '%s' to '%s'",
 764                   oldname, event->name);
 765
 766         strscpy(name, IFNAMSIZ, event->name);
 767
 768         r = sd_rtnl_open(&rtnl, 0);
 769         if (r < 0)
 770                 return r;
 771
 772         r = rtnl_set_link_name(rtnl, udev_device_get_ifindex(dev), name);
 773         if (r < 0)
 774                 log_error("error changing net interface name %s to %s: %s",
 775                           oldname, name, strerror(-r));
 776         else
 777                 print_kmsg("renamed network interface %s to %s\n", oldname, name);
 778
 779         return r;
 780 }
 781
 782 void udev_event_execute_rules(struct udev_event *event,
 783                               usec_t timeout_usec,
 784                               struct udev_rules *rules, const sigset_t *sigmask) {
 785         struct udev_device *dev = event->dev;
 786
 787         if (udev_device_get_subsystem(dev) == NULL)
 788                 return;
 789
 790         if (streq(udev_device_get_action(dev), "remove")) {
 791                 udev_device_read_db(dev, NULL);
 792                 udev_device_delete_db(dev);
 793                 udev_device_tag_index(dev, NULL, false);
 794
 795                 if (major(udev_device_get_devnum(dev)) != 0)
 796                         udev_watch_end(event->udev, dev);
 797
 798                 udev_rules_apply_to_event(rules, event, timeout_usec, sigmask);
 799
 800                 if (major(udev_device_get_devnum(dev)) != 0)
 801                         udev_node_remove(dev);
 802         } else {
 803                 event->dev_db = udev_device_new(event->udev);
 804                 if (event->dev_db != NULL) {
 805                         udev_device_set_syspath(event->dev_db, udev_device_get_syspath(dev));
 806                         udev_device_set_subsystem(event->dev_db, udev_device_get_subsystem(dev));
 807                         udev_device_read_db(event->dev_db, NULL);
 808                         udev_device_set_info_loaded(event->dev_db);
 809
 810                         /* disable watch during event processing */
 811                         if (major(udev_device_get_devnum(dev)) != 0)
 812                                 udev_watch_end(event->udev, event->dev_db);
 813                 }
 814
 815                 udev_rules_apply_to_event(rules, event, timeout_usec, sigmask);
 816
 817                 /* rename a new network interface, if needed */
 818                 if (udev_device_get_ifindex(dev) > 0 && streq(udev_device_get_action(dev), "add") &&
 819                     event->name != NULL && !streq(event->name, udev_device_get_sysname(dev))) {
 820                         char syspath[UTIL_PATH_SIZE];
 821                         char *pos;
 822                         int r;
 823
 824                         r = rename_netif(event);
 825                         if (r >= 0) {
 826                                 log_debug("renamed netif to '%s'", event->name);
 827
 828                                 /* remember old name */
 829                                 udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
 830
 831                                 /* now change the devpath, because the kernel device name has changed */
 832                                 strscpy(syspath, sizeof(syspath), udev_device_get_syspath(dev));
 833                                 pos = strrchr(syspath, '/');
 834                                 if (pos != NULL) {
 835                                         pos++;
 836                                         strscpy(pos, sizeof(syspath) - (pos - syspath), event->name);
 837                                         udev_device_set_syspath(event->dev, syspath);
 838                                         udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
 839                                         log_debug("changed devpath to '%s'", udev_device_get_devpath(dev));
 840                                 }
 841                         }
 842                 }
 843
 844                 if (major(udev_device_get_devnum(dev)) > 0) {
 845                         bool apply;
 846
 847                         /* remove/update possible left-over symlinks from old database entry */
 848                         if (event->dev_db != NULL)
 849                                 udev_node_update_old_links(dev, event->dev_db);
 850
 851                         if (!event->owner_set)
 852                                 event->uid = udev_device_get_devnode_uid(dev);
 853
 854                         if (!event->group_set)
 855                                 event->gid = udev_device_get_devnode_gid(dev);
 856
 857                         if (!event->mode_set) {
 858                                 if (udev_device_get_devnode_mode(dev) > 0) {
 859                                         /* kernel supplied value */
 860                                         event->mode = udev_device_get_devnode_mode(dev);
 861                                 } else if (event->gid > 0) {
 862                                         /* default 0660 if a group is assigned */
 863                                         event->mode = 0660;
 864                                 } else {
 865                                         /* default 0600 */
 866                                         event->mode = 0600;
 867                                 }
 868                         }
 869
 870                         apply = streq(udev_device_get_action(dev), "add") || event->owner_set || event->group_set || event->mode_set;
 871                         udev_node_add(dev, apply, event->mode, event->uid, event->gid, &event->seclabel_list);
 872                 }
 873
 874                 /* preserve old, or get new initialization timestamp */
 875                 if (event->dev_db != NULL && udev_device_get_usec_initialized(event->dev_db) > 0)
 876                         udev_device_set_usec_initialized(event->dev, udev_device_get_usec_initialized(event->dev_db));
 877                 else if (udev_device_get_usec_initialized(event->dev) == 0)
 878                         udev_device_set_usec_initialized(event->dev, now(CLOCK_MONOTONIC));
 879
 880                 /* (re)write database file */
 881                 udev_device_update_db(dev);
 882                 udev_device_tag_index(dev, event->dev_db, true);
 883                 udev_device_set_is_initialized(dev);
 884
 885                 udev_device_unref(event->dev_db);
 886                 event->dev_db = NULL;
 887         }
 888 }
 889
 890 void udev_event_execute_run(struct udev_event *event, usec_t timeout_usec, const sigset_t *sigmask) {
 891         struct udev_list_entry *list_entry;
 892
 893         udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
 894                 const char *cmd = udev_list_entry_get_name(list_entry);
 895                 enum udev_builtin_cmd builtin_cmd = udev_list_entry_get_num(list_entry);
 896
 897                 if (builtin_cmd < UDEV_BUILTIN_MAX) {
 898                         char command[UTIL_PATH_SIZE];
 899
 900                         udev_event_apply_format(event, cmd, command, sizeof(command));
 901                         udev_builtin_run(event->dev, builtin_cmd, command, false);
 902                 } else {
 903                         char program[UTIL_PATH_SIZE];
 904                         char **envp;
 905
 906                         if (event->exec_delay > 0) {
 907                                 log_debug("delay execution of '%s'", program);
 908                                 sleep(event->exec_delay);
 909                         }
 910
 911                         udev_event_apply_format(event, cmd, program, sizeof(program));
 912                         envp = udev_device_get_properties_envp(event->dev);
 913                         udev_event_spawn(event, timeout_usec, program, envp, sigmask, NULL, 0);
 914                 }
 915         }
 916 }