src/udev/udev-event.c

   1 /*
   2  * Copyright (C) 2003-2010 Kay Sievers <kay.sievers@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_usec();
  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                 char *name;
  90                 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 < ARRAY_SIZE(map); i++) {
 136                                         if (strncmp(&from[1], map[i].name, strlen(map[i].name)) == 0) {
 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 < ARRAY_SIZE(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 = util_strpcpy(&s, l, udev_device_get_devpath(dev));
 195                         break;
 196                 case SUBST_KERNEL:
 197                         l = util_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 = util_strpcpy(&s, l, udev_device_get_sysnum(dev));
 203                         break;
 204                 case SUBST_ID:
 205                         if (event->dev_parent == NULL)
 206                                 break;
 207                         l = util_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 = util_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 = util_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 = util_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                                 util_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                                 util_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 = util_strpcpy(&s, l, tmp);
 270                         } else {
 271                                 l = util_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                                 util_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 = util_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                                 size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
 323
 324                                 l = util_strpcpy(&s, l, &devnode[devlen]);
 325                         }
 326                         break;
 327                 }
 328                 case SUBST_DEVNODE:
 329                         if (udev_device_get_devnode(dev) != NULL)
 330                                 l = util_strpcpy(&s, l, udev_device_get_devnode(dev));
 331                         break;
 332                 case SUBST_NAME: {
 333                         if (event->name != NULL) {
 334                                 l = util_strpcpy(&s, l, event->name);
 335                         } else if (udev_device_get_devnode(dev) != NULL) {
 336                                 size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
 337
 338                                 l = util_strpcpy(&s, l, &udev_device_get_devnode(dev)[devlen]);
 339                         } else {
 340                                 l = util_strpcpy(&s, l, udev_device_get_sysname(dev));
 341                         }
 342                         break;
 343                 }
 344                 case SUBST_LINKS: {
 345                         size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
 346                         struct udev_list_entry *list_entry;
 347
 348                         list_entry = udev_device_get_devlinks_list_entry(dev);
 349                         if (list_entry == NULL)
 350                                 break;
 351                         l = util_strpcpy(&s, l, &udev_list_entry_get_name(list_entry)[devlen]);
 352                         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
 353                                 l = util_strpcpyl(&s, l, " ", &udev_list_entry_get_name(list_entry)[devlen], NULL);
 354                         break;
 355                 }
 356                 case SUBST_ROOT:
 357                         l = util_strpcpy(&s, l, udev_get_dev_path(event->udev));
 358                         break;
 359                 case SUBST_SYS:
 360                         l = util_strpcpy(&s, l, udev_get_sys_path(event->udev));
 361                         break;
 362                 case SUBST_ENV:
 363                         if (attr == NULL) {
 364                                 break;
 365                         } else {
 366                                 const char *value;
 367
 368                                 value = udev_device_get_property_value(event->dev, attr);
 369                                 if (value == NULL)
 370                                         break;
 371                                 l = util_strpcpy(&s, l, value);
 372                                 break;
 373                         }
 374                 default:
 375                         log_error("unknown substitution type=%i\n", type);
 376                         break;
 377                 }
 378         }
 379
 380 out:
 381         s[0] = '\0';
 382         return l;
 383 }
 384
 385 static int spawn_exec(struct udev_event *event,
 386                       const char *cmd, char *const argv[], char **envp, const sigset_t *sigmask,
 387                       int fd_stdout, int fd_stderr)
 388 {
 389         struct udev *udev = event->udev;
 390         int err;
 391         int fd;
 392
 393         /* discard child output or connect to pipe */
 394         fd = open("/dev/null", O_RDWR);
 395         if (fd >= 0) {
 396                 dup2(fd, STDIN_FILENO);
 397                 if (fd_stdout < 0)
 398                         dup2(fd, STDOUT_FILENO);
 399                 if (fd_stderr < 0)
 400                         dup2(fd, STDERR_FILENO);
 401                 close(fd);
 402         } else {
 403                 log_error("open /dev/null failed: %m\n");
 404         }
 405
 406         /* connect pipes to std{out,err} */
 407         if (fd_stdout >= 0) {
 408                 dup2(fd_stdout, STDOUT_FILENO);
 409                         close(fd_stdout);
 410         }
 411         if (fd_stderr >= 0) {
 412                 dup2(fd_stderr, STDERR_FILENO);
 413                 close(fd_stderr);
 414         }
 415
 416         /* terminate child in case parent goes away */
 417         prctl(PR_SET_PDEATHSIG, SIGTERM);
 418
 419         /* restore original udev sigmask before exec */
 420         if (sigmask)
 421                 sigprocmask(SIG_SETMASK, sigmask, NULL);
 422
 423         execve(argv[0], argv, envp);
 424
 425         /* exec failed */
 426         err = -errno;
 427         log_error("failed to execute '%s' '%s': %m\n", argv[0], cmd);
 428         return err;
 429 }
 430
 431 static void spawn_read(struct udev_event *event,
 432                       const char *cmd,
 433                       int fd_stdout, int fd_stderr,
 434                       char *result, size_t ressize)
 435 {
 436         struct udev *udev = event->udev;
 437         size_t respos = 0;
 438         int fd_ep = -1;
 439         struct epoll_event ep_outpipe, ep_errpipe;
 440
 441         /* read from child if requested */
 442         if (fd_stdout < 0 && fd_stderr < 0)
 443                 return;
 444
 445         fd_ep = epoll_create1(EPOLL_CLOEXEC);
 446         if (fd_ep < 0) {
 447                 log_error("error creating epoll fd: %m\n");
 448                 goto out;
 449         }
 450
 451         if (fd_stdout >= 0) {
 452                 memset(&ep_outpipe, 0, sizeof(struct epoll_event));
 453                 ep_outpipe.events = EPOLLIN;
 454                 ep_outpipe.data.ptr = &fd_stdout;
 455                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe) < 0) {
 456                         log_error("fail to add fd to epoll: %m\n");
 457                         goto out;
 458                 }
 459         }
 460
 461         if (fd_stderr >= 0) {
 462                 memset(&ep_errpipe, 0, sizeof(struct epoll_event));
 463                 ep_errpipe.events = EPOLLIN;
 464                 ep_errpipe.data.ptr = &fd_stderr;
 465                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe) < 0) {
 466                         log_error("fail to add fd to epoll: %m\n");
 467                         goto out;
 468                 }
 469         }
 470
 471         /* read child output */
 472         while (fd_stdout >= 0 || fd_stderr >= 0) {
 473                 int timeout;
 474                 int fdcount;
 475                 struct epoll_event ev[4];
 476                 int i;
 477
 478                 if (event->timeout_usec > 0) {
 479                         unsigned long long age_usec;
 480
 481                         age_usec = now_usec() - event->birth_usec;
 482                         if (age_usec >= event->timeout_usec) {
 483                                 log_error("timeout '%s'\n", cmd);
 484                                 goto out;
 485                         }
 486                         timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
 487                 } else {
 488                         timeout = -1;
 489                 }
 490
 491                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
 492                 if (fdcount < 0) {
 493                         if (errno == EINTR)
 494                                 continue;
 495                         log_error("failed to poll: %m\n");
 496                         goto out;
 497                 }
 498                 if (fdcount == 0) {
 499                         log_error("timeout '%s'\n", cmd);
 500                         goto out;
 501                 }
 502
 503                 for (i = 0; i < fdcount; i++) {
 504                         int *fd = (int *)ev[i].data.ptr;
 505
 506                         if (ev[i].events & EPOLLIN) {
 507                                 ssize_t count;
 508                                 char buf[4096];
 509
 510                                 count = read(*fd, buf, sizeof(buf)-1);
 511                                 if (count <= 0)
 512                                         continue;
 513                                 buf[count] = '\0';
 514
 515                                 /* store stdout result */
 516                                 if (result != NULL && *fd == fd_stdout) {
 517                                         if (respos + count < ressize) {
 518                                                 memcpy(&result[respos], buf, count);
 519                                                 respos += count;
 520                                         } else {
 521                                                 log_error("'%s' ressize %zd too short\n", cmd, ressize);
 522                                         }
 523                                 }
 524
 525                                 /* log debug output only if we watch stderr */
 526                                 if (fd_stderr >= 0) {
 527                                         char *pos;
 528                                         char *line;
 529
 530                                         pos = buf;
 531                                         while ((line = strsep(&pos, "\n"))) {
 532                                                 if (pos != NULL || line[0] != '\0')
 533                                                         log_debug("'%s'(%s) '%s'\n", cmd, *fd == fd_stdout ? "out" : "err" , line);
 534                                         }
 535                                 }
 536                         } else if (ev[i].events & EPOLLHUP) {
 537                                 if (epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL) < 0) {
 538                                         log_error("failed to remove fd from epoll: %m\n");
 539                                         goto out;
 540                                 }
 541                                 *fd = -1;
 542                         }
 543                 }
 544         }
 545
 546         /* return the child's stdout string */
 547         if (result != NULL)
 548                 result[respos] = '\0';
 549 out:
 550         if (fd_ep >= 0)
 551                 close(fd_ep);
 552 }
 553
 554 static int spawn_wait(struct udev_event *event, const char *cmd, pid_t pid)
 555 {
 556         struct udev *udev = event->udev;
 557         struct pollfd pfd[1];
 558         int err = 0;
 559
 560         pfd[0].events = POLLIN;
 561         pfd[0].fd = event->fd_signal;
 562
 563         while (pid > 0) {
 564                 int timeout;
 565                 int fdcount;
 566
 567                 if (event->timeout_usec > 0) {
 568                         unsigned long long age_usec;
 569
 570                         age_usec = now_usec() - event->birth_usec;
 571                         if (age_usec >= event->timeout_usec)
 572                                 timeout = 1000;
 573                         else
 574                                 timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
 575                 } else {
 576                         timeout = -1;
 577                 }
 578
 579                 fdcount = poll(pfd, 1, timeout);
 580                 if (fdcount < 0) {
 581                         if (errno == EINTR)
 582                                 continue;
 583                         err = -errno;
 584                         log_error("failed to poll: %m\n");
 585                         goto out;
 586                 }
 587                 if (fdcount == 0) {
 588                         log_error("timeout: killing '%s' [%u]\n", cmd, pid);
 589                         kill(pid, SIGKILL);
 590                 }
 591
 592                 if (pfd[0].revents & POLLIN) {
 593                         struct signalfd_siginfo fdsi;
 594                         int status;
 595                         ssize_t size;
 596
 597                         size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 598                         if (size != sizeof(struct signalfd_siginfo))
 599                                 continue;
 600
 601                         switch (fdsi.ssi_signo) {
 602                         case SIGTERM:
 603                                 event->sigterm = true;
 604                                 break;
 605                         case SIGCHLD:
 606                                 if (waitpid(pid, &status, WNOHANG) < 0)
 607                                         break;
 608                                 if (WIFEXITED(status)) {
 609                                         log_debug("'%s' [%u] exit with return code %i\n", cmd, pid, WEXITSTATUS(status));
 610                                         if (WEXITSTATUS(status) != 0)
 611                                                 err = -1;
 612                                 } else if (WIFSIGNALED(status)) {
 613                                         log_error("'%s' [%u] terminated by signal %i (%s)\n", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 614                                         err = -1;
 615                                 } else if (WIFSTOPPED(status)) {
 616                                         log_error("'%s' [%u] stopped\n", cmd, pid);
 617                                         err = -1;
 618                                 } else if (WIFCONTINUED(status)) {
 619                                         log_error("'%s' [%u] continued\n", cmd, pid);
 620                                         err = -1;
 621                                 } else {
 622                                         log_error("'%s' [%u] exit with status 0x%04x\n", cmd, pid, status);
 623                                         err = -1;
 624                                 }
 625                                 pid = 0;
 626                                 break;
 627                         }
 628                 }
 629         }
 630 out:
 631         return err;
 632 }
 633
 634 int udev_build_argv(struct udev *udev, char *cmd, int *argc, char *argv[])
 635 {
 636         int i = 0;
 637         char *pos;
 638
 639         if (strchr(cmd, ' ') == NULL) {
 640                 argv[i++] = cmd;
 641                 goto out;
 642         }
 643
 644         pos = cmd;
 645         while (pos != NULL && pos[0] != '\0') {
 646                 if (pos[0] == '\'') {
 647                         /* do not separate quotes */
 648                         pos++;
 649                         argv[i] = strsep(&pos, "\'");
 650                         if (pos != NULL)
 651                                 while (pos[0] == ' ')
 652                                         pos++;
 653                 } else {
 654                         argv[i] = strsep(&pos, " ");
 655                         if (pos != NULL)
 656                                 while (pos[0] == ' ')
 657                                         pos++;
 658                 }
 659                 i++;
 660         }
 661 out:
 662         argv[i] = NULL;
 663         if (argc)
 664                 *argc = i;
 665         return 0;
 666 }
 667
 668 int udev_event_spawn(struct udev_event *event,
 669                      const char *cmd, char **envp, const sigset_t *sigmask,
 670                      char *result, size_t ressize)
 671 {
 672         struct udev *udev = event->udev;
 673         int outpipe[2] = {-1, -1};
 674         int errpipe[2] = {-1, -1};
 675         pid_t pid;
 676         char arg[UTIL_PATH_SIZE];
 677         char *argv[128];
 678         char program[UTIL_PATH_SIZE];
 679         int err = 0;
 680
 681         util_strscpy(arg, sizeof(arg), cmd);
 682         udev_build_argv(event->udev, arg, NULL, argv);
 683
 684         /* pipes from child to parent */
 685         if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
 686                 if (pipe2(outpipe, O_NONBLOCK) != 0) {
 687                         err = -errno;
 688                         log_error("pipe failed: %m\n");
 689                         goto out;
 690                 }
 691         }
 692         if (udev_get_log_priority(udev) >= LOG_INFO) {
 693                 if (pipe2(errpipe, O_NONBLOCK) != 0) {
 694                         err = -errno;
 695                         log_error("pipe failed: %m\n");
 696                         goto out;
 697                 }
 698         }
 699
 700         /* allow programs in /usr/lib/udev/ to be called without the path */
 701         if (argv[0][0] != '/') {
 702                 util_strscpyl(program, sizeof(program), UDEVLIBEXECDIR "/", argv[0], NULL);
 703                 argv[0] = program;
 704         }
 705
 706         pid = fork();
 707         switch(pid) {
 708         case 0:
 709                 /* child closes parent's ends of pipes */
 710                 if (outpipe[READ_END] >= 0) {
 711                         close(outpipe[READ_END]);
 712                         outpipe[READ_END] = -1;
 713                 }
 714                 if (errpipe[READ_END] >= 0) {
 715                         close(errpipe[READ_END]);
 716                         errpipe[READ_END] = -1;
 717                 }
 718
 719                 log_debug("starting '%s'\n", cmd);
 720
 721                 err = spawn_exec(event, cmd, argv, envp, sigmask,
 722                                  outpipe[WRITE_END], errpipe[WRITE_END]);
 723
 724                 _exit(2 );
 725         case -1:
 726                 log_error("fork of '%s' failed: %m\n", cmd);
 727                 err = -1;
 728                 goto out;
 729         default:
 730                 /* parent closed child's ends of pipes */
 731                 if (outpipe[WRITE_END] >= 0) {
 732                         close(outpipe[WRITE_END]);
 733                         outpipe[WRITE_END] = -1;
 734                 }
 735                 if (errpipe[WRITE_END] >= 0) {
 736                         close(errpipe[WRITE_END]);
 737                         errpipe[WRITE_END] = -1;
 738                 }
 739
 740                 spawn_read(event, cmd,
 741                          outpipe[READ_END], errpipe[READ_END],
 742                          result, ressize);
 743
 744                 err = spawn_wait(event, cmd, pid);
 745         }
 746
 747 out:
 748         if (outpipe[READ_END] >= 0)
 749                 close(outpipe[READ_END]);
 750         if (outpipe[WRITE_END] >= 0)
 751                 close(outpipe[WRITE_END]);
 752         if (errpipe[READ_END] >= 0)
 753                 close(errpipe[READ_END]);
 754         if (errpipe[WRITE_END] >= 0)
 755                 close(errpipe[WRITE_END]);
 756         return err;
 757 }
 758
 759 static void rename_netif_kernel_log(struct ifreq ifr)
 760 {
 761         int klog;
 762         FILE *f;
 763
 764         klog = open("/dev/kmsg", O_WRONLY);
 765         if (klog < 0)
 766                 return;
 767
 768         f = fdopen(klog, "w");
 769         if (f == NULL) {
 770                 close(klog);
 771                 return;
 772         }
 773
 774         fprintf(f, "<30>udevd[%u]: renamed network interface %s to %s\n",
 775                 getpid(), ifr.ifr_name, ifr.ifr_newname);
 776         fclose(f);
 777 }
 778
 779 static int rename_netif(struct udev_event *event)
 780 {
 781         struct udev_device *dev = event->dev;
 782         int sk;
 783         struct ifreq ifr;
 784         int loop;
 785         int err;
 786
 787         log_debug("changing net interface name from '%s' to '%s'\n",
 788                   udev_device_get_sysname(dev), event->name);
 789
 790         sk = socket(PF_INET, SOCK_DGRAM, 0);
 791         if (sk < 0) {
 792                 err = -errno;
 793                 log_error("error opening socket: %m\n");
 794                 return err;
 795         }
 796
 797         memset(&ifr, 0x00, sizeof(struct ifreq));
 798         util_strscpy(ifr.ifr_name, IFNAMSIZ, udev_device_get_sysname(dev));
 799         util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
 800         err = ioctl(sk, SIOCSIFNAME, &ifr);
 801         if (err == 0) {
 802                 rename_netif_kernel_log(ifr);
 803                 goto out;
 804         }
 805
 806         /* keep trying if the destination interface name already exists */
 807         err = -errno;
 808         if (err != -EEXIST)
 809                 goto out;
 810
 811         /* free our own name, another process may wait for us */
 812         snprintf(ifr.ifr_newname, IFNAMSIZ, "rename%u", udev_device_get_ifindex(dev));
 813         err = ioctl(sk, SIOCSIFNAME, &ifr);
 814         if (err < 0) {
 815                 err = -errno;
 816                 goto out;
 817         }
 818
 819         /* log temporary name */
 820         rename_netif_kernel_log(ifr);
 821
 822         /* wait a maximum of 90 seconds for our target to become available */
 823         util_strscpy(ifr.ifr_name, IFNAMSIZ, ifr.ifr_newname);
 824         util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
 825         loop = 90 * 20;
 826         while (loop--) {
 827                 const struct timespec duration = { 0, 1000 * 1000 * 1000 / 20 };
 828
 829                 nanosleep(&duration, NULL);
 830
 831                 err = ioctl(sk, SIOCSIFNAME, &ifr);
 832                 if (err == 0) {
 833                         rename_netif_kernel_log(ifr);
 834                         break;
 835                 }
 836                 err = -errno;
 837                 if (err != -EEXIST)
 838                         break;
 839         }
 840
 841 out:
 842         if (err < 0)
 843                 log_error("error changing net interface name %s to %s: %m\n", ifr.ifr_name, ifr.ifr_newname);
 844         close(sk);
 845         return err;
 846 }
 847
 848 int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules, const sigset_t *sigmask)
 849 {
 850         struct udev_device *dev = event->dev;
 851         int err = 0;
 852
 853         if (udev_device_get_subsystem(dev) == NULL)
 854                 return -1;
 855
 856         if (strcmp(udev_device_get_action(dev), "remove") == 0) {
 857                 udev_device_read_db(dev, NULL);
 858                 udev_device_delete_db(dev);
 859                 udev_device_tag_index(dev, NULL, false);
 860
 861                 if (major(udev_device_get_devnum(dev)) != 0)
 862                         udev_watch_end(event->udev, dev);
 863
 864                 udev_rules_apply_to_event(rules, event, sigmask);
 865
 866                 if (major(udev_device_get_devnum(dev)) != 0)
 867                         udev_node_remove(dev);
 868         } else {
 869                 event->dev_db = udev_device_new_from_syspath(event->udev, udev_device_get_syspath(dev));
 870                 if (event->dev_db != NULL) {
 871                         udev_device_read_db(event->dev_db, NULL);
 872                         udev_device_set_info_loaded(event->dev_db);
 873
 874                         /* disable watch during event processing */
 875                         if (major(udev_device_get_devnum(dev)) != 0)
 876                                 udev_watch_end(event->udev, event->dev_db);
 877                 }
 878
 879                 udev_rules_apply_to_event(rules, event, sigmask);
 880
 881                 /* rename a new network interface, if needed */
 882                 if (udev_device_get_ifindex(dev) > 0 && strcmp(udev_device_get_action(dev), "add") == 0 &&
 883                     event->name != NULL && strcmp(event->name, udev_device_get_sysname(dev)) != 0) {
 884                         char syspath[UTIL_PATH_SIZE];
 885                         char *pos;
 886
 887                         err = rename_netif(event);
 888                         if (err == 0) {
 889                                 log_debug("renamed netif to '%s'\n", event->name);
 890
 891                                 /* remember old name */
 892                                 udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
 893
 894                                 /* now change the devpath, because the kernel device name has changed */
 895                                 util_strscpy(syspath, sizeof(syspath), udev_device_get_syspath(dev));
 896                                 pos = strrchr(syspath, '/');
 897                                 if (pos != NULL) {
 898                                         pos++;
 899                                         util_strscpy(pos, sizeof(syspath) - (pos - syspath), event->name);
 900                                         udev_device_set_syspath(event->dev, syspath);
 901                                         udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
 902                                         log_debug("changed devpath to '%s'\n", udev_device_get_devpath(dev));
 903                                 }
 904                         }
 905                 }
 906
 907                 if (major(udev_device_get_devnum(dev)) > 0) {
 908                         /* remove/update possible left-over symlinks from old database entry */
 909                         if (event->dev_db != NULL)
 910                                 udev_node_update_old_links(dev, event->dev_db);
 911
 912                         if (!event->mode_set) {
 913                                 if (udev_device_get_devnode_mode(dev) > 0) {
 914                                         /* kernel supplied value */
 915                                         event->mode = udev_device_get_devnode_mode(dev);
 916                                 } else if (event->gid > 0) {
 917                                         /* default 0660 if a group is assigned */
 918                                         event->mode = 0660;
 919                                 } else {
 920                                         /* default 0600 */
 921                                         event->mode = 0600;
 922                                 }
 923                         }
 924
 925                         udev_node_add(dev, event->mode, event->uid, event->gid);
 926                 }
 927
 928                 /* preserve old, or get new initialization timestamp */
 929                 if (event->dev_db != NULL && udev_device_get_usec_initialized(event->dev_db) > 0)
 930                         udev_device_set_usec_initialized(event->dev, udev_device_get_usec_initialized(event->dev_db));
 931                 else if (udev_device_get_usec_initialized(event->dev) == 0)
 932                         udev_device_set_usec_initialized(event->dev, now_usec());
 933
 934                 /* (re)write database file */
 935                 udev_device_update_db(dev);
 936                 udev_device_tag_index(dev, event->dev_db, true);
 937                 udev_device_set_is_initialized(dev);
 938
 939                 udev_device_unref(event->dev_db);
 940                 event->dev_db = NULL;
 941         }
 942 out:
 943         return err;
 944 }
 945
 946 void udev_event_execute_run(struct udev_event *event, const sigset_t *sigmask)
 947 {
 948         struct udev_list_entry *list_entry;
 949
 950         udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
 951                 const char *cmd = udev_list_entry_get_name(list_entry);
 952                 enum udev_builtin_cmd builtin_cmd = udev_list_entry_get_num(list_entry);
 953
 954                 if (builtin_cmd < UDEV_BUILTIN_MAX) {
 955                         char command[UTIL_PATH_SIZE];
 956
 957                         udev_event_apply_format(event, cmd, command, sizeof(command));
 958                         udev_builtin_run(event->dev, builtin_cmd, command, false);
 959                 } else {
 960                         char program[UTIL_PATH_SIZE];
 961                         char **envp;
 962
 963                         if (event->exec_delay > 0) {
 964                                 log_debug("delay execution of '%s'\n", program);
 965                                 sleep(event->exec_delay);
 966                         }
 967
 968                         udev_event_apply_format(event, cmd, program, sizeof(program));
 969                         envp = udev_device_get_properties_envp(event->dev);
 970                         udev_event_spawn(event, program, envp, sigmask, NULL, 0);
 971                 }
 972         }
 973 }