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                 const char *name;
  90                 const char fmt;
  91                 enum subst_type type;
  92         } map[] = {
  93                 { .name = "devnode",        .fmt = 'N',        .type = SUBST_DEVNODE },
  94                 { .name = "tempnode",        .fmt = 'N',        .type = SUBST_DEVNODE },
  95                 { .name = "attr",        .fmt = 's',        .type = SUBST_ATTR },
  96                 { .name = "sysfs",        .fmt = 's',        .type = SUBST_ATTR },
  97                 { .name = "env",        .fmt = 'E',        .type = SUBST_ENV },
  98                 { .name = "kernel",        .fmt = 'k',        .type = SUBST_KERNEL },
  99                 { .name = "number",        .fmt = 'n',        .type = SUBST_KERNEL_NUMBER },
 100                 { .name = "driver",        .fmt = 'd',        .type = SUBST_DRIVER },
 101                 { .name = "devpath",        .fmt = 'p',        .type = SUBST_DEVPATH },
 102                 { .name = "id",                .fmt = 'b',        .type = SUBST_ID },
 103                 { .name = "major",        .fmt = 'M',        .type = SUBST_MAJOR },
 104                 { .name = "minor",        .fmt = 'm',        .type = SUBST_MINOR },
 105                 { .name = "result",        .fmt = 'c',        .type = SUBST_RESULT },
 106                 { .name = "parent",        .fmt = 'P',        .type = SUBST_PARENT },
 107                 { .name = "name",        .fmt = 'D',        .type = SUBST_NAME },
 108                 { .name = "links",        .fmt = 'L',        .type = SUBST_LINKS },
 109                 { .name = "root",        .fmt = 'r',        .type = SUBST_ROOT },
 110                 { .name = "sys",        .fmt = 'S',        .type = SUBST_SYS },
 111         };
 112         const char *from;
 113         char *s;
 114         size_t l;
 115
 116         from = src;
 117         s = dest;
 118         l = size;
 119
 120         for (;;) {
 121                 enum subst_type type = SUBST_UNKNOWN;
 122                 char attrbuf[UTIL_PATH_SIZE];
 123                 char *attr = NULL;
 124
 125                 while (from[0] != '\0') {
 126                         if (from[0] == '$') {
 127                                 /* substitute named variable */
 128                                 unsigned int i;
 129
 130                                 if (from[1] == '$') {
 131                                         from++;
 132                                         goto copy;
 133                                 }
 134
 135                                 for (i = 0; i < ELEMENTSOF(map); i++) {
 136                                         if (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 < ELEMENTSOF(map); i++) {
 152                                         if (from[1] == map[i].fmt) {
 153                                                 type = map[i].type;
 154                                                 from += 2;
 155                                                 goto subst;
 156                                         }
 157                                 }
 158                         }
 159 copy:
 160                         /* copy char */
 161                         if (l == 0)
 162                                 goto out;
 163                         s[0] = from[0];
 164                         from++;
 165                         s++;
 166                         l--;
 167                 }
 168
 169                 goto out;
 170 subst:
 171                 /* extract possible $format{attr} */
 172                 if (from[0] == '{') {
 173                         unsigned int i;
 174
 175                         from++;
 176                         for (i = 0; from[i] != '}'; i++) {
 177                                 if (from[i] == '\0') {
 178                                         log_error("missing closing brace for format '%s'\n", src);
 179                                         goto out;
 180                                 }
 181                         }
 182                         if (i >= sizeof(attrbuf))
 183                                 goto out;
 184                         memcpy(attrbuf, from, i);
 185                         attrbuf[i] = '\0';
 186                         from += i+1;
 187                         attr = attrbuf;
 188                 } else {
 189                         attr = NULL;
 190                 }
 191
 192                 switch (type) {
 193                 case SUBST_DEVPATH:
 194                         l = 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         int err;
 390         int fd;
 391
 392         /* discard child output or connect to pipe */
 393         fd = open("/dev/null", O_RDWR);
 394         if (fd >= 0) {
 395                 dup2(fd, STDIN_FILENO);
 396                 if (fd_stdout < 0)
 397                         dup2(fd, STDOUT_FILENO);
 398                 if (fd_stderr < 0)
 399                         dup2(fd, STDERR_FILENO);
 400                 close(fd);
 401         } else {
 402                 log_error("open /dev/null failed: %m\n");
 403         }
 404
 405         /* connect pipes to std{out,err} */
 406         if (fd_stdout >= 0) {
 407                 dup2(fd_stdout, STDOUT_FILENO);
 408                         close(fd_stdout);
 409         }
 410         if (fd_stderr >= 0) {
 411                 dup2(fd_stderr, STDERR_FILENO);
 412                 close(fd_stderr);
 413         }
 414
 415         /* terminate child in case parent goes away */
 416         prctl(PR_SET_PDEATHSIG, SIGTERM);
 417
 418         /* restore original udev sigmask before exec */
 419         if (sigmask)
 420                 sigprocmask(SIG_SETMASK, sigmask, NULL);
 421
 422         execve(argv[0], argv, envp);
 423
 424         /* exec failed */
 425         err = -errno;
 426         log_error("failed to execute '%s' '%s': %m\n", argv[0], cmd);
 427         return err;
 428 }
 429
 430 static void spawn_read(struct udev_event *event,
 431                       const char *cmd,
 432                       int fd_stdout, int fd_stderr,
 433                       char *result, size_t ressize)
 434 {
 435         size_t respos = 0;
 436         int fd_ep = -1;
 437         struct epoll_event ep_outpipe, ep_errpipe;
 438
 439         /* read from child if requested */
 440         if (fd_stdout < 0 && fd_stderr < 0)
 441                 return;
 442
 443         fd_ep = epoll_create1(EPOLL_CLOEXEC);
 444         if (fd_ep < 0) {
 445                 log_error("error creating epoll fd: %m\n");
 446                 goto out;
 447         }
 448
 449         if (fd_stdout >= 0) {
 450                 memset(&ep_outpipe, 0, sizeof(struct epoll_event));
 451                 ep_outpipe.events = EPOLLIN;
 452                 ep_outpipe.data.ptr = &fd_stdout;
 453                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe) < 0) {
 454                         log_error("fail to add fd to epoll: %m\n");
 455                         goto out;
 456                 }
 457         }
 458
 459         if (fd_stderr >= 0) {
 460                 memset(&ep_errpipe, 0, sizeof(struct epoll_event));
 461                 ep_errpipe.events = EPOLLIN;
 462                 ep_errpipe.data.ptr = &fd_stderr;
 463                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe) < 0) {
 464                         log_error("fail to add fd to epoll: %m\n");
 465                         goto out;
 466                 }
 467         }
 468
 469         /* read child output */
 470         while (fd_stdout >= 0 || fd_stderr >= 0) {
 471                 int timeout;
 472                 int fdcount;
 473                 struct epoll_event ev[4];
 474                 int i;
 475
 476                 if (event->timeout_usec > 0) {
 477                         unsigned long long age_usec;
 478
 479                         age_usec = now_usec() - event->birth_usec;
 480                         if (age_usec >= event->timeout_usec) {
 481                                 log_error("timeout '%s'\n", cmd);
 482                                 goto out;
 483                         }
 484                         timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
 485                 } else {
 486                         timeout = -1;
 487                 }
 488
 489                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
 490                 if (fdcount < 0) {
 491                         if (errno == EINTR)
 492                                 continue;
 493                         log_error("failed to poll: %m\n");
 494                         goto out;
 495                 }
 496                 if (fdcount == 0) {
 497                         log_error("timeout '%s'\n", cmd);
 498                         goto out;
 499                 }
 500
 501                 for (i = 0; i < fdcount; i++) {
 502                         int *fd = (int *)ev[i].data.ptr;
 503
 504                         if (ev[i].events & EPOLLIN) {
 505                                 ssize_t count;
 506                                 char buf[4096];
 507
 508                                 count = read(*fd, buf, sizeof(buf)-1);
 509                                 if (count <= 0)
 510                                         continue;
 511                                 buf[count] = '\0';
 512
 513                                 /* store stdout result */
 514                                 if (result != NULL && *fd == fd_stdout) {
 515                                         if (respos + count < ressize) {
 516                                                 memcpy(&result[respos], buf, count);
 517                                                 respos += count;
 518                                         } else {
 519                                                 log_error("'%s' ressize %zd too short\n", cmd, ressize);
 520                                         }
 521                                 }
 522
 523                                 /* log debug output only if we watch stderr */
 524                                 if (fd_stderr >= 0) {
 525                                         char *pos;
 526                                         char *line;
 527
 528                                         pos = buf;
 529                                         while ((line = strsep(&pos, "\n"))) {
 530                                                 if (pos != NULL || line[0] != '\0')
 531                                                         log_debug("'%s'(%s) '%s'\n", cmd, *fd == fd_stdout ? "out" : "err" , line);
 532                                         }
 533                                 }
 534                         } else if (ev[i].events & EPOLLHUP) {
 535                                 if (epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL) < 0) {
 536                                         log_error("failed to remove fd from epoll: %m\n");
 537                                         goto out;
 538                                 }
 539                                 *fd = -1;
 540                         }
 541                 }
 542         }
 543
 544         /* return the child's stdout string */
 545         if (result != NULL)
 546                 result[respos] = '\0';
 547 out:
 548         if (fd_ep >= 0)
 549                 close(fd_ep);
 550 }
 551
 552 static int spawn_wait(struct udev_event *event, const char *cmd, pid_t pid)
 553 {
 554         struct pollfd pfd[1];
 555         int err = 0;
 556
 557         pfd[0].events = POLLIN;
 558         pfd[0].fd = event->fd_signal;
 559
 560         while (pid > 0) {
 561                 int timeout;
 562                 int fdcount;
 563
 564                 if (event->timeout_usec > 0) {
 565                         unsigned long long age_usec;
 566
 567                         age_usec = now_usec() - event->birth_usec;
 568                         if (age_usec >= event->timeout_usec)
 569                                 timeout = 1000;
 570                         else
 571                                 timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
 572                 } else {
 573                         timeout = -1;
 574                 }
 575
 576                 fdcount = poll(pfd, 1, timeout);
 577                 if (fdcount < 0) {
 578                         if (errno == EINTR)
 579                                 continue;
 580                         err = -errno;
 581                         log_error("failed to poll: %m\n");
 582                         goto out;
 583                 }
 584                 if (fdcount == 0) {
 585                         log_error("timeout: killing '%s' [%u]\n", cmd, pid);
 586                         kill(pid, SIGKILL);
 587                 }
 588
 589                 if (pfd[0].revents & POLLIN) {
 590                         struct signalfd_siginfo fdsi;
 591                         int status;
 592                         ssize_t size;
 593
 594                         size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 595                         if (size != sizeof(struct signalfd_siginfo))
 596                                 continue;
 597
 598                         switch (fdsi.ssi_signo) {
 599                         case SIGTERM:
 600                                 event->sigterm = true;
 601                                 break;
 602                         case SIGCHLD:
 603                                 if (waitpid(pid, &status, WNOHANG) < 0)
 604                                         break;
 605                                 if (WIFEXITED(status)) {
 606                                         log_debug("'%s' [%u] exit with return code %i\n", cmd, pid, WEXITSTATUS(status));
 607                                         if (WEXITSTATUS(status) != 0)
 608                                                 err = -1;
 609                                 } else if (WIFSIGNALED(status)) {
 610                                         log_error("'%s' [%u] terminated by signal %i (%s)\n", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 611                                         err = -1;
 612                                 } else if (WIFSTOPPED(status)) {
 613                                         log_error("'%s' [%u] stopped\n", cmd, pid);
 614                                         err = -1;
 615                                 } else if (WIFCONTINUED(status)) {
 616                                         log_error("'%s' [%u] continued\n", cmd, pid);
 617                                         err = -1;
 618                                 } else {
 619                                         log_error("'%s' [%u] exit with status 0x%04x\n", cmd, pid, status);
 620                                         err = -1;
 621                                 }
 622                                 pid = 0;
 623                                 break;
 624                         }
 625                 }
 626         }
 627 out:
 628         return err;
 629 }
 630
 631 int udev_build_argv(struct udev *udev, char *cmd, int *argc, char *argv[])
 632 {
 633         int i = 0;
 634         char *pos;
 635
 636         if (strchr(cmd, ' ') == NULL) {
 637                 argv[i++] = cmd;
 638                 goto out;
 639         }
 640
 641         pos = cmd;
 642         while (pos != NULL && pos[0] != '\0') {
 643                 if (pos[0] == '\'') {
 644                         /* do not separate quotes */
 645                         pos++;
 646                         argv[i] = strsep(&pos, "\'");
 647                         if (pos != NULL)
 648                                 while (pos[0] == ' ')
 649                                         pos++;
 650                 } else {
 651                         argv[i] = strsep(&pos, " ");
 652                         if (pos != NULL)
 653                                 while (pos[0] == ' ')
 654                                         pos++;
 655                 }
 656                 i++;
 657         }
 658 out:
 659         argv[i] = NULL;
 660         if (argc)
 661                 *argc = i;
 662         return 0;
 663 }
 664
 665 int udev_event_spawn(struct udev_event *event,
 666                      const char *cmd, char **envp, const sigset_t *sigmask,
 667                      char *result, size_t ressize)
 668 {
 669         struct udev *udev = event->udev;
 670         int outpipe[2] = {-1, -1};
 671         int errpipe[2] = {-1, -1};
 672         pid_t pid;
 673         char arg[UTIL_PATH_SIZE];
 674         char *argv[128];
 675         char program[UTIL_PATH_SIZE];
 676         int err = 0;
 677
 678         util_strscpy(arg, sizeof(arg), cmd);
 679         udev_build_argv(event->udev, arg, NULL, argv);
 680
 681         /* pipes from child to parent */
 682         if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
 683                 if (pipe2(outpipe, O_NONBLOCK) != 0) {
 684                         err = -errno;
 685                         log_error("pipe failed: %m\n");
 686                         goto out;
 687                 }
 688         }
 689         if (udev_get_log_priority(udev) >= LOG_INFO) {
 690                 if (pipe2(errpipe, O_NONBLOCK) != 0) {
 691                         err = -errno;
 692                         log_error("pipe failed: %m\n");
 693                         goto out;
 694                 }
 695         }
 696
 697         /* allow programs in /usr/lib/udev/ to be called without the path */
 698         if (argv[0][0] != '/') {
 699                 util_strscpyl(program, sizeof(program), UDEVLIBEXECDIR "/", argv[0], NULL);
 700                 argv[0] = program;
 701         }
 702
 703         pid = fork();
 704         switch(pid) {
 705         case 0:
 706                 /* child closes parent's ends of pipes */
 707                 if (outpipe[READ_END] >= 0) {
 708                         close(outpipe[READ_END]);
 709                         outpipe[READ_END] = -1;
 710                 }
 711                 if (errpipe[READ_END] >= 0) {
 712                         close(errpipe[READ_END]);
 713                         errpipe[READ_END] = -1;
 714                 }
 715
 716                 log_debug("starting '%s'\n", cmd);
 717
 718                 spawn_exec(event, cmd, argv, envp, sigmask,
 719                            outpipe[WRITE_END], errpipe[WRITE_END]);
 720
 721                 _exit(2 );
 722         case -1:
 723                 log_error("fork of '%s' failed: %m\n", cmd);
 724                 err = -1;
 725                 goto out;
 726         default:
 727                 /* parent closed child's ends of pipes */
 728                 if (outpipe[WRITE_END] >= 0) {
 729                         close(outpipe[WRITE_END]);
 730                         outpipe[WRITE_END] = -1;
 731                 }
 732                 if (errpipe[WRITE_END] >= 0) {
 733                         close(errpipe[WRITE_END]);
 734                         errpipe[WRITE_END] = -1;
 735                 }
 736
 737                 spawn_read(event, cmd,
 738                          outpipe[READ_END], errpipe[READ_END],
 739                          result, ressize);
 740
 741                 err = spawn_wait(event, cmd, pid);
 742         }
 743
 744 out:
 745         if (outpipe[READ_END] >= 0)
 746                 close(outpipe[READ_END]);
 747         if (outpipe[WRITE_END] >= 0)
 748                 close(outpipe[WRITE_END]);
 749         if (errpipe[READ_END] >= 0)
 750                 close(errpipe[READ_END]);
 751         if (errpipe[WRITE_END] >= 0)
 752                 close(errpipe[WRITE_END]);
 753         return err;
 754 }
 755
 756 static void rename_netif_kernel_log(struct ifreq ifr)
 757 {
 758         int klog;
 759         FILE *f;
 760
 761         klog = open("/dev/kmsg", O_WRONLY);
 762         if (klog < 0)
 763                 return;
 764
 765         f = fdopen(klog, "w");
 766         if (f == NULL) {
 767                 close(klog);
 768                 return;
 769         }
 770
 771         fprintf(f, "<30>udevd[%u]: renamed network interface %s to %s\n",
 772                 getpid(), ifr.ifr_name, ifr.ifr_newname);
 773         fclose(f);
 774 }
 775
 776 static int rename_netif(struct udev_event *event)
 777 {
 778         struct udev_device *dev = event->dev;
 779         int sk;
 780         struct ifreq ifr;
 781         int loop;
 782         int err;
 783
 784         log_debug("changing net interface name from '%s' to '%s'\n",
 785                   udev_device_get_sysname(dev), event->name);
 786
 787         sk = socket(PF_INET, SOCK_DGRAM, 0);
 788         if (sk < 0) {
 789                 err = -errno;
 790                 log_error("error opening socket: %m\n");
 791                 return err;
 792         }
 793
 794         memset(&ifr, 0x00, sizeof(struct ifreq));
 795         util_strscpy(ifr.ifr_name, IFNAMSIZ, udev_device_get_sysname(dev));
 796         util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
 797         err = ioctl(sk, SIOCSIFNAME, &ifr);
 798         if (err == 0) {
 799                 rename_netif_kernel_log(ifr);
 800                 goto out;
 801         }
 802
 803         /* keep trying if the destination interface name already exists */
 804         err = -errno;
 805         if (err != -EEXIST)
 806                 goto out;
 807
 808         /* free our own name, another process may wait for us */
 809         snprintf(ifr.ifr_newname, IFNAMSIZ, "rename%u", udev_device_get_ifindex(dev));
 810         err = ioctl(sk, SIOCSIFNAME, &ifr);
 811         if (err < 0) {
 812                 err = -errno;
 813                 goto out;
 814         }
 815
 816         /* log temporary name */
 817         rename_netif_kernel_log(ifr);
 818
 819         /* wait a maximum of 90 seconds for our target to become available */
 820         util_strscpy(ifr.ifr_name, IFNAMSIZ, ifr.ifr_newname);
 821         util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
 822         loop = 90 * 20;
 823         while (loop--) {
 824                 const struct timespec duration = { 0, 1000 * 1000 * 1000 / 20 };
 825
 826                 nanosleep(&duration, NULL);
 827
 828                 err = ioctl(sk, SIOCSIFNAME, &ifr);
 829                 if (err == 0) {
 830                         rename_netif_kernel_log(ifr);
 831                         break;
 832                 }
 833                 err = -errno;
 834                 if (err != -EEXIST)
 835                         break;
 836         }
 837
 838 out:
 839         if (err < 0)
 840                 log_error("error changing net interface name %s to %s: %m\n", ifr.ifr_name, ifr.ifr_newname);
 841         close(sk);
 842         return err;
 843 }
 844
 845 int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules, const sigset_t *sigmask)
 846 {
 847         struct udev_device *dev = event->dev;
 848         int err = 0;
 849
 850         if (udev_device_get_subsystem(dev) == NULL)
 851                 return -1;
 852
 853         if (strcmp(udev_device_get_action(dev), "remove") == 0) {
 854                 udev_device_read_db(dev, NULL);
 855                 udev_device_delete_db(dev);
 856                 udev_device_tag_index(dev, NULL, false);
 857
 858                 if (major(udev_device_get_devnum(dev)) != 0)
 859                         udev_watch_end(event->udev, dev);
 860
 861                 udev_rules_apply_to_event(rules, event, sigmask);
 862
 863                 if (major(udev_device_get_devnum(dev)) != 0)
 864                         udev_node_remove(dev);
 865         } else {
 866                 event->dev_db = udev_device_new_from_syspath(event->udev, udev_device_get_syspath(dev));
 867                 if (event->dev_db != NULL) {
 868                         udev_device_read_db(event->dev_db, NULL);
 869                         udev_device_set_info_loaded(event->dev_db);
 870
 871                         /* disable watch during event processing */
 872                         if (major(udev_device_get_devnum(dev)) != 0)
 873                                 udev_watch_end(event->udev, event->dev_db);
 874                 }
 875
 876                 udev_rules_apply_to_event(rules, event, sigmask);
 877
 878                 /* rename a new network interface, if needed */
 879                 if (udev_device_get_ifindex(dev) > 0 && strcmp(udev_device_get_action(dev), "add") == 0 &&
 880                     event->name != NULL && strcmp(event->name, udev_device_get_sysname(dev)) != 0) {
 881                         char syspath[UTIL_PATH_SIZE];
 882                         char *pos;
 883
 884                         err = rename_netif(event);
 885                         if (err == 0) {
 886                                 log_debug("renamed netif to '%s'\n", event->name);
 887
 888                                 /* remember old name */
 889                                 udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
 890
 891                                 /* now change the devpath, because the kernel device name has changed */
 892                                 util_strscpy(syspath, sizeof(syspath), udev_device_get_syspath(dev));
 893                                 pos = strrchr(syspath, '/');
 894                                 if (pos != NULL) {
 895                                         pos++;
 896                                         util_strscpy(pos, sizeof(syspath) - (pos - syspath), event->name);
 897                                         udev_device_set_syspath(event->dev, syspath);
 898                                         udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
 899                                         log_debug("changed devpath to '%s'\n", udev_device_get_devpath(dev));
 900                                 }
 901                         }
 902                 }
 903
 904                 if (major(udev_device_get_devnum(dev)) > 0) {
 905                         /* remove/update possible left-over symlinks from old database entry */
 906                         if (event->dev_db != NULL)
 907                                 udev_node_update_old_links(dev, event->dev_db);
 908
 909                         if (!event->mode_set) {
 910                                 if (udev_device_get_devnode_mode(dev) > 0) {
 911                                         /* kernel supplied value */
 912                                         event->mode = udev_device_get_devnode_mode(dev);
 913                                 } else if (event->gid > 0) {
 914                                         /* default 0660 if a group is assigned */
 915                                         event->mode = 0660;
 916                                 } else {
 917                                         /* default 0600 */
 918                                         event->mode = 0600;
 919                                 }
 920                         }
 921
 922                         udev_node_add(dev, event->mode, event->uid, event->gid);
 923                 }
 924
 925                 /* preserve old, or get new initialization timestamp */
 926                 if (event->dev_db != NULL && udev_device_get_usec_initialized(event->dev_db) > 0)
 927                         udev_device_set_usec_initialized(event->dev, udev_device_get_usec_initialized(event->dev_db));
 928                 else if (udev_device_get_usec_initialized(event->dev) == 0)
 929                         udev_device_set_usec_initialized(event->dev, now_usec());
 930
 931                 /* (re)write database file */
 932                 udev_device_update_db(dev);
 933                 udev_device_tag_index(dev, event->dev_db, true);
 934                 udev_device_set_is_initialized(dev);
 935
 936                 udev_device_unref(event->dev_db);
 937                 event->dev_db = NULL;
 938         }
 939         return err;
 940 }
 941
 942 void udev_event_execute_run(struct udev_event *event, const sigset_t *sigmask)
 943 {
 944         struct udev_list_entry *list_entry;
 945
 946         udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
 947                 const char *cmd = udev_list_entry_get_name(list_entry);
 948                 enum udev_builtin_cmd builtin_cmd = udev_list_entry_get_num(list_entry);
 949
 950                 if (builtin_cmd < UDEV_BUILTIN_MAX) {
 951                         char command[UTIL_PATH_SIZE];
 952
 953                         udev_event_apply_format(event, cmd, command, sizeof(command));
 954                         udev_builtin_run(event->dev, builtin_cmd, command, false);
 955                 } else {
 956                         char program[UTIL_PATH_SIZE];
 957                         char **envp;
 958
 959                         if (event->exec_delay > 0) {
 960                                 log_debug("delay execution of '%s'\n", program);
 961                                 sleep(event->exec_delay);
 962                         }
 963
 964                         udev_event_apply_format(event, cmd, program, sizeof(program));
 965                         envp = udev_device_get_properties_envp(event->dev);
 966                         udev_event_spawn(event, program, envp, sigmask, NULL, 0);
 967                 }
 968         }
 969 }