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_event *event;
  42
  43         event = calloc(1, sizeof(struct udev_event));
  44         if (event == NULL)
  45                 return NULL;
  46         event->dev = dev;
  47         event->udev = udev_device_get_udev(dev);
  48         udev_list_init(&event->run_list);
  49         event->fd_signal = -1;
  50         event->birth_usec = now_usec();
  51         event->timeout_usec = 60 * 1000 * 1000;
  52         dbg(event->udev, "allocated event %p\n", event);
  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_entries(event->udev, &event->run_list);
  61         free(event->tmp_node);
  62         free(event->program_result);
  63         free(event->name);
  64         dbg(event->udev, "free event %p\n", event);
  65         free(event);
  66 }
  67
  68 size_t udev_event_apply_format(struct udev_event *event, const char *src, char *dest, size_t size)
  69 {
  70         struct udev_device *dev = event->dev;
  71         enum subst_type {
  72                 SUBST_UNKNOWN,
  73                 SUBST_TEMP_NODE,
  74                 SUBST_ATTR,
  75                 SUBST_ENV,
  76                 SUBST_KERNEL,
  77                 SUBST_KERNEL_NUMBER,
  78                 SUBST_DRIVER,
  79                 SUBST_DEVPATH,
  80                 SUBST_ID,
  81                 SUBST_MAJOR,
  82                 SUBST_MINOR,
  83                 SUBST_RESULT,
  84                 SUBST_PARENT,
  85                 SUBST_NAME,
  86                 SUBST_LINKS,
  87                 SUBST_ROOT,
  88                 SUBST_SYS,
  89         };
  90         static const struct subst_map {
  91                 char *name;
  92                 char fmt;
  93                 enum subst_type type;
  94         } map[] = {
  95                 { .name = "tempnode",   .fmt = 'N',     .type = SUBST_TEMP_NODE },
  96                 { .name = "attr",       .fmt = 's',     .type = SUBST_ATTR },
  97                 { .name = "sysfs",      .fmt = 's',     .type = SUBST_ATTR },
  98                 { .name = "env",        .fmt = 'E',     .type = SUBST_ENV },
  99                 { .name = "kernel",     .fmt = 'k',     .type = SUBST_KERNEL },
 100                 { .name = "number",     .fmt = 'n',     .type = SUBST_KERNEL_NUMBER },
 101                 { .name = "driver",     .fmt = 'd',     .type = SUBST_DRIVER },
 102                 { .name = "devpath",    .fmt = 'p',     .type = SUBST_DEVPATH },
 103                 { .name = "id",         .fmt = 'b',     .type = SUBST_ID },
 104                 { .name = "major",      .fmt = 'M',     .type = SUBST_MAJOR },
 105                 { .name = "minor",      .fmt = 'm',     .type = SUBST_MINOR },
 106                 { .name = "result",     .fmt = 'c',     .type = SUBST_RESULT },
 107                 { .name = "parent",     .fmt = 'P',     .type = SUBST_PARENT },
 108                 { .name = "name",       .fmt = 'D',     .type = SUBST_NAME },
 109                 { .name = "links",      .fmt = 'L',     .type = SUBST_LINKS },
 110                 { .name = "root",       .fmt = 'r',     .type = SUBST_ROOT },
 111                 { .name = "sys",        .fmt = 'S',     .type = SUBST_SYS },
 112         };
 113         const char *from;
 114         char *s;
 115         size_t l;
 116
 117         from = src;
 118         s = dest;
 119         l = size;
 120
 121         for (;;) {
 122                 enum subst_type type = SUBST_UNKNOWN;
 123                 char attrbuf[UTIL_PATH_SIZE];
 124                 char *attr = NULL;
 125
 126                 while (from[0] != '\0') {
 127                         if (from[0] == '$') {
 128                                 /* substitute named variable */
 129                                 unsigned int i;
 130
 131                                 if (from[1] == '$') {
 132                                         from++;
 133                                         goto copy;
 134                                 }
 135
 136                                 for (i = 0; i < ARRAY_SIZE(map); i++) {
 137                                         if (strncmp(&from[1], map[i].name, strlen(map[i].name)) == 0) {
 138                                                 type = map[i].type;
 139                                                 from += strlen(map[i].name)+1;
 140                                                 dbg(event->udev, "will substitute format name '%s'\n", map[i].name);
 141                                                 goto subst;
 142                                         }
 143                                 }
 144                         } else if (from[0] == '%') {
 145                                 /* substitute format char */
 146                                 unsigned int i;
 147
 148                                 if (from[1] == '%') {
 149                                         from++;
 150                                         goto copy;
 151                                 }
 152
 153                                 for (i = 0; i < ARRAY_SIZE(map); i++) {
 154                                         if (from[1] == map[i].fmt) {
 155                                                 type = map[i].type;
 156                                                 from += 2;
 157                                                 dbg(event->udev, "will substitute format char '%c'\n", map[i].fmt);
 158                                                 goto subst;
 159                                         }
 160                                 }
 161                         }
 162 copy:
 163                         /* copy char */
 164                         if (l == 0)
 165                                 goto out;
 166                         s[0] = from[0];
 167                         from++;
 168                         s++;
 169                         l--;
 170                 }
 171
 172                 goto out;
 173 subst:
 174                 /* extract possible $format{attr} */
 175                 if (from[0] == '{') {
 176                         unsigned int i;
 177
 178                         from++;
 179                         for (i = 0; from[i] != '}'; i++) {
 180                                 if (from[i] == '\0') {
 181                                         err(event->udev, "missing closing brace for format '%s'\n", src);
 182                                         goto out;
 183                                 }
 184                         }
 185                         if (i >= sizeof(attrbuf))
 186                                 goto out;
 187                         memcpy(attrbuf, from, i);
 188                         attrbuf[i] = '\0';
 189                         from += i+1;
 190                         attr = attrbuf;
 191                 } else {
 192                         attr = NULL;
 193                 }
 194
 195                 switch (type) {
 196                 case SUBST_DEVPATH:
 197                         l = util_strpcpy(&s, l, udev_device_get_devpath(dev));
 198                         dbg(event->udev, "substitute devpath '%s'\n", udev_device_get_devpath(dev));
 199                         break;
 200                 case SUBST_KERNEL:
 201                         l = util_strpcpy(&s, l, udev_device_get_sysname(dev));
 202                         dbg(event->udev, "substitute kernel name '%s'\n", udev_device_get_sysname(dev));
 203                         break;
 204                 case SUBST_KERNEL_NUMBER:
 205                         if (udev_device_get_sysnum(dev) == NULL)
 206                                 break;
 207                         l = util_strpcpy(&s, l, udev_device_get_sysnum(dev));
 208                         dbg(event->udev, "substitute kernel number '%s'\n", udev_device_get_sysnum(dev));
 209                         break;
 210                 case SUBST_ID:
 211                         if (event->dev_parent == NULL)
 212                                 break;
 213                         l = util_strpcpy(&s, l, udev_device_get_sysname(event->dev_parent));
 214                         dbg(event->udev, "substitute id '%s'\n", udev_device_get_sysname(event->dev_parent));
 215                         break;
 216                 case SUBST_DRIVER: {
 217                         const char *driver;
 218
 219                         if (event->dev_parent == NULL)
 220                                 break;
 221
 222                         driver = udev_device_get_driver(event->dev_parent);
 223                         if (driver == NULL)
 224                                 break;
 225                         l = util_strpcpy(&s, l, driver);
 226                         dbg(event->udev, "substitute driver '%s'\n", driver);
 227                         break;
 228                 }
 229                 case SUBST_MAJOR: {
 230                         char num[UTIL_PATH_SIZE];
 231
 232                         sprintf(num, "%d", major(udev_device_get_devnum(dev)));
 233                         l = util_strpcpy(&s, l, num);
 234                         dbg(event->udev, "substitute major number '%s'\n", num);
 235                         break;
 236                 }
 237                 case SUBST_MINOR: {
 238                         char num[UTIL_PATH_SIZE];
 239
 240                         sprintf(num, "%d", minor(udev_device_get_devnum(dev)));
 241                         l = util_strpcpy(&s, l, num);
 242                         dbg(event->udev, "substitute minor number '%s'\n", num);
 243                         break;
 244                 }
 245                 case SUBST_RESULT: {
 246                         char *rest;
 247                         int i;
 248
 249                         if (event->program_result == NULL)
 250                                 break;
 251                         /* get part part of the result string */
 252                         i = 0;
 253                         if (attr != NULL)
 254                                 i = strtoul(attr, &rest, 10);
 255                         if (i > 0) {
 256                                 char result[UTIL_PATH_SIZE];
 257                                 char tmp[UTIL_PATH_SIZE];
 258                                 char *cpos;
 259
 260                                 dbg(event->udev, "request part #%d of result string\n", i);
 261                                 util_strscpy(result, sizeof(result), event->program_result);
 262                                 cpos = result;
 263                                 while (--i) {
 264                                         while (cpos[0] != '\0' && !isspace(cpos[0]))
 265                                                 cpos++;
 266                                         while (isspace(cpos[0]))
 267                                                 cpos++;
 268                                 }
 269                                 if (i > 0) {
 270                                         err(event->udev, "requested part of result string not found\n");
 271                                         break;
 272                                 }
 273                                 util_strscpy(tmp, sizeof(tmp), cpos);
 274                                 /* %{2+}c copies the whole string from the second part on */
 275                                 if (rest[0] != '+') {
 276                                         cpos = strchr(tmp, ' ');
 277                                         if (cpos)
 278                                                 cpos[0] = '\0';
 279                                 }
 280                                 l = util_strpcpy(&s, l, tmp);
 281                                 dbg(event->udev, "substitute part of result string '%s'\n", tmp);
 282                         } else {
 283                                 l = util_strpcpy(&s, l, event->program_result);
 284                                 dbg(event->udev, "substitute result string '%s'\n", event->program_result);
 285                         }
 286                         break;
 287                 }
 288                 case SUBST_ATTR: {
 289                         const char *value = NULL;
 290                         char vbuf[UTIL_NAME_SIZE];
 291                         size_t len;
 292                         int count;
 293
 294                         if (attr == NULL) {
 295                                 err(event->udev, "missing file parameter for attr\n");
 296                                 break;
 297                         }
 298
 299                         /* try to read the value specified by "[dmi/id]product_name" */
 300                         if (util_resolve_subsys_kernel(event->udev, attr, vbuf, sizeof(vbuf), 1) == 0)
 301                                 value = vbuf;
 302
 303                         /* try to read the attribute the device */
 304                         if (value == NULL)
 305                                 value = udev_device_get_sysattr_value(event->dev, attr);
 306
 307                         /* try to read the attribute of the parent device, other matches have selected */
 308                         if (value == NULL && event->dev_parent != NULL && event->dev_parent != event->dev)
 309                                 value = udev_device_get_sysattr_value(event->dev_parent, attr);
 310
 311                         if (value == NULL)
 312                                 break;
 313
 314                         /* strip trailing whitespace, and replace unwanted characters */
 315                         if (value != vbuf)
 316                                 util_strscpy(vbuf, sizeof(vbuf), value);
 317                         len = strlen(vbuf);
 318                         while (len > 0 && isspace(vbuf[--len]))
 319                                 vbuf[len] = '\0';
 320                         count = udev_util_replace_chars(vbuf, UDEV_ALLOWED_CHARS_INPUT);
 321                         if (count > 0)
 322                                 info(event->udev, "%i character(s) replaced\n" , count);
 323                         l = util_strpcpy(&s, l, vbuf);
 324                         dbg(event->udev, "substitute sysfs value '%s'\n", vbuf);
 325                         break;
 326                 }
 327                 case SUBST_PARENT: {
 328                         struct udev_device *dev_parent;
 329                         const char *devnode;
 330
 331                         dev_parent = udev_device_get_parent(event->dev);
 332                         if (dev_parent == NULL)
 333                                 break;
 334                                 devnode = udev_device_get_devnode(dev_parent);
 335                         if (devnode != NULL) {
 336                                 size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
 337
 338                                 l = util_strpcpy(&s, l, &devnode[devlen]);
 339                                 dbg(event->udev, "found parent '%s', got node name '%s'\n",
 340                                     udev_device_get_syspath(dev_parent), &devnode[devlen]);
 341                         }
 342                         break;
 343                 }
 344                 case SUBST_TEMP_NODE: {
 345                         dev_t devnum;
 346                         struct stat statbuf;
 347                         char filename[UTIL_PATH_SIZE];
 348                         const char *devtype;
 349
 350                         if (event->tmp_node != NULL) {
 351                                 l = util_strpcpy(&s, l, event->tmp_node);
 352                                 dbg(event->udev, "tempnode: return earlier created one\n");
 353                                 break;
 354                         }
 355                         devnum = udev_device_get_devnum(dev);
 356                         if (major(devnum) == 0)
 357                                 break;
 358                         /* lookup kernel provided node */
 359                         if (udev_device_get_knodename(dev) != NULL) {
 360                                 util_strscpyl(filename, sizeof(filename),
 361                                               udev_get_dev_path(event->udev), "/", udev_device_get_knodename(dev), NULL);
 362                                 if (stat(filename, &statbuf) == 0 && statbuf.st_rdev == devnum) {
 363                                         l = util_strpcpy(&s, l, filename);
 364                                         dbg(event->udev, "tempnode: return kernel node\n");
 365                                         break;
 366                                 }
 367                         }
 368                         /* lookup /dev/{char,block}/<maj>:<min> */
 369                         if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
 370                                 devtype = "block";
 371                         else
 372                                 devtype = "char";
 373                         snprintf(filename, sizeof(filename), "%s/%s/%u:%u",
 374                                  udev_get_dev_path(event->udev), devtype,
 375                                  major(udev_device_get_devnum(dev)),
 376                                  minor(udev_device_get_devnum(dev)));
 377                         if (stat(filename, &statbuf) == 0 && statbuf.st_rdev == devnum) {
 378                                 l = util_strpcpy(&s, l, filename);
 379                                 dbg(event->udev, "tempnode: return maj:min node\n");
 380                                 break;
 381                         }
 382                         /* create temporary node */
 383                         dbg(event->udev, "tempnode: create temp node\n");
 384                         asprintf(&event->tmp_node, "%s/.tmp-%s-%u:%u",
 385                                  udev_get_dev_path(event->udev), devtype,
 386                                  major(udev_device_get_devnum(dev)),
 387                                  minor(udev_device_get_devnum(dev)));
 388                         if (event->tmp_node == NULL)
 389                                 break;
 390                         udev_node_mknod(dev, event->tmp_node, 0600, 0, 0);
 391                         l = util_strpcpy(&s, l, event->tmp_node);
 392                         break;
 393                 }
 394                 case SUBST_NAME:
 395                         if (event->name != NULL) {
 396                                 l = util_strpcpy(&s, l, event->name);
 397                                 dbg(event->udev, "substitute name '%s'\n", event->name);
 398                         } else {
 399                                 l = util_strpcpy(&s, l, udev_device_get_sysname(dev));
 400                                 dbg(event->udev, "substitute sysname '%s'\n", udev_device_get_sysname(dev));
 401                         }
 402                         break;
 403                 case SUBST_LINKS: {
 404                         size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
 405                         struct udev_list_entry *list_entry;
 406
 407                         list_entry = udev_device_get_devlinks_list_entry(dev);
 408                         if (list_entry == NULL)
 409                                 break;
 410                         l = util_strpcpy(&s, l, &udev_list_entry_get_name(list_entry)[devlen]);
 411                         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
 412                                 l = util_strpcpyl(&s, l, " ", &udev_list_entry_get_name(list_entry)[devlen], NULL);
 413                         break;
 414                 }
 415                 case SUBST_ROOT:
 416                         l = util_strpcpy(&s, l, udev_get_dev_path(event->udev));
 417                         dbg(event->udev, "substitute udev_root '%s'\n", udev_get_dev_path(event->udev));
 418                         break;
 419                 case SUBST_SYS:
 420                         l = util_strpcpy(&s, l, udev_get_sys_path(event->udev));
 421                         dbg(event->udev, "substitute sys_path '%s'\n", udev_get_sys_path(event->udev));
 422                         break;
 423                 case SUBST_ENV:
 424                         if (attr == NULL) {
 425                                 dbg(event->udev, "missing attribute\n");
 426                                 break;
 427                         } else {
 428                                 const char *value;
 429
 430                                 value = udev_device_get_property_value(event->dev, attr);
 431                                 if (value == NULL)
 432                                         break;
 433                                 dbg(event->udev, "substitute env '%s=%s'\n", attr, value);
 434                                 l = util_strpcpy(&s, l, value);
 435                                 break;
 436                         }
 437                 default:
 438                         err(event->udev, "unknown substitution type=%i\n", type);
 439                         break;
 440                 }
 441         }
 442
 443 out:
 444         s[0] = '\0';
 445         dbg(event->udev, "'%s' -> '%s' (%zu)\n", src, dest, l);
 446         return l;
 447 }
 448
 449 static int spawn_exec(struct udev_event *event,
 450                       const char *cmd, char *const argv[], char **envp, const sigset_t *sigmask,
 451                       int fd_stdout, int fd_stderr)
 452 {
 453         struct udev *udev = event->udev;
 454         int err;
 455         int fd;
 456
 457         /* discard child output or connect to pipe */
 458         fd = open("/dev/null", O_RDWR);
 459         if (fd >= 0) {
 460                 dup2(fd, STDIN_FILENO);
 461                 if (fd_stdout < 0)
 462                         dup2(fd, STDOUT_FILENO);
 463                 if (fd_stderr < 0)
 464                         dup2(fd, STDERR_FILENO);
 465                 close(fd);
 466         } else {
 467                 err(udev, "open /dev/null failed: %m\n");
 468         }
 469
 470         /* connect pipes to std{out,err} */
 471         if (fd_stdout >= 0) {
 472                 dup2(fd_stdout, STDOUT_FILENO);
 473                         close(fd_stdout);
 474         }
 475         if (fd_stderr >= 0) {
 476                 dup2(fd_stderr, STDERR_FILENO);
 477                 close(fd_stderr);
 478         }
 479
 480         /* terminate child in case parent goes away */
 481         prctl(PR_SET_PDEATHSIG, SIGTERM);
 482
 483         /* restore original udev sigmask before exec */
 484         if (sigmask)
 485                 sigprocmask(SIG_SETMASK, sigmask, NULL);
 486
 487         execve(argv[0], argv, envp);
 488
 489         /* exec failed */
 490         err = -errno;
 491         err(udev, "failed to execute '%s' '%s': %m\n", argv[0], cmd);
 492         return err;
 493 }
 494
 495 static int spawn_read(struct udev_event *event,
 496                       const char *cmd,
 497                       int fd_stdout, int fd_stderr,
 498                       char *result, size_t ressize)
 499 {
 500         struct udev *udev = event->udev;
 501         size_t respos = 0;
 502         int fd_ep = -1;
 503         struct epoll_event ep_outpipe, ep_errpipe;
 504         int err = 0;
 505
 506         /* read from child if requested */
 507         if (fd_stdout < 0 && fd_stderr < 0)
 508                 return 0;
 509
 510         fd_ep = epoll_create1(EPOLL_CLOEXEC);
 511         if (fd_ep < 0) {
 512                 err = -errno;
 513                 err(udev, "error creating epoll fd: %m\n");
 514                 goto out;
 515         }
 516
 517         if (fd_stdout >= 0) {
 518                 memset(&ep_outpipe, 0, sizeof(struct epoll_event));
 519                 ep_outpipe.events = EPOLLIN;
 520                 ep_outpipe.data.ptr = &fd_stdout;
 521                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe) < 0) {
 522                         err(udev, "fail to add fd to epoll: %m\n");
 523                         goto out;
 524                 }
 525         }
 526
 527         if (fd_stderr >= 0) {
 528                 memset(&ep_errpipe, 0, sizeof(struct epoll_event));
 529                 ep_errpipe.events = EPOLLIN;
 530                 ep_errpipe.data.ptr = &fd_stderr;
 531                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe) < 0) {
 532                         err(udev, "fail to add fd to epoll: %m\n");
 533                         goto out;
 534                 }
 535         }
 536
 537         /* read child output */
 538         while (fd_stdout >= 0 || fd_stderr >= 0) {
 539                 int timeout;
 540                 int fdcount;
 541                 struct epoll_event ev[4];
 542                 int i;
 543
 544                 if (event->timeout_usec > 0) {
 545                         unsigned long long age_usec;
 546
 547                         age_usec = now_usec() - event->birth_usec;
 548                         if (age_usec >= event->timeout_usec) {
 549                                 err = -ETIMEDOUT;
 550                                 err(udev, "timeout '%s'\n", cmd);
 551                                 goto out;
 552                         }
 553                         timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
 554                 } else {
 555                         timeout = -1;
 556                 }
 557
 558                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
 559                 if (fdcount < 0) {
 560                         if (errno == EINTR)
 561                                 continue;
 562                         err = -errno;
 563                         err(udev, "failed to poll: %m\n");
 564                         goto out;
 565                 }
 566                 if (fdcount == 0) {
 567                         err  = -ETIMEDOUT;
 568                         err(udev, "timeout '%s'\n", cmd);
 569                         goto out;
 570                 }
 571
 572                 for (i = 0; i < fdcount; i++) {
 573                         int *fd = (int *)ev[i].data.ptr;
 574
 575                         if (ev[i].events & EPOLLIN) {
 576                                 ssize_t count;
 577                                 char buf[4096];
 578
 579                                 count = read(*fd, buf, sizeof(buf)-1);
 580                                 if (count <= 0)
 581                                         continue;
 582                                 buf[count] = '\0';
 583
 584                                 /* store stdout result */
 585                                 if (result != NULL && *fd == fd_stdout) {
 586                                         if (respos + count < ressize) {
 587                                                 memcpy(&result[respos], buf, count);
 588                                                 respos += count;
 589                                         } else {
 590                                                 err(udev, "'%s' ressize %zd too short\n", cmd, ressize);
 591                                                 err = -ENOBUFS;
 592                                         }
 593                                 }
 594
 595                                 /* log debug output only if we watch stderr */
 596                                 if (fd_stderr >= 0) {
 597                                         char *pos;
 598                                         char *line;
 599
 600                                         pos = buf;
 601                                         while ((line = strsep(&pos, "\n"))) {
 602                                                 if (pos != NULL || line[0] != '\0')
 603                                                         info(udev, "'%s'(%s) '%s'\n", cmd, *fd == fd_stdout ? "out" : "err" , line);
 604                                         }
 605                                 }
 606                         } else if (ev[i].events & EPOLLHUP) {
 607                                 if (epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL) < 0) {
 608                                         err = -errno;
 609                                         err(udev, "failed to remove fd from epoll: %m\n");
 610                                         goto out;
 611                                 }
 612                                 *fd = -1;
 613                         }
 614                 }
 615         }
 616
 617         /* return the child's stdout string */
 618         if (result != NULL) {
 619                 result[respos] = '\0';
 620                 dbg(udev, "result='%s'\n", result);
 621         }
 622 out:
 623         if (fd_ep >= 0)
 624                 close(fd_ep);
 625         return err;
 626 }
 627
 628 static int spawn_wait(struct udev_event *event, const char *cmd, pid_t pid)
 629 {
 630         struct udev *udev = event->udev;
 631         struct pollfd pfd[1];
 632         int err = 0;
 633
 634         pfd[0].events = POLLIN;
 635         pfd[0].fd = event->fd_signal;
 636
 637         while (pid > 0) {
 638                 int timeout;
 639                 int fdcount;
 640
 641                 if (event->timeout_usec > 0) {
 642                         unsigned long long age_usec;
 643
 644                         age_usec = now_usec() - event->birth_usec;
 645                         if (age_usec >= event->timeout_usec)
 646                                 timeout = 1000;
 647                         else
 648                                 timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
 649                 } else {
 650                         timeout = -1;
 651                 }
 652
 653                 fdcount = poll(pfd, 1, timeout);
 654                 if (fdcount < 0) {
 655                         if (errno == EINTR)
 656                                 continue;
 657                         err = -errno;
 658                         err(udev, "failed to poll: %m\n");
 659                         goto out;
 660                 }
 661                 if (fdcount == 0) {
 662                         err(udev, "timeout: killing '%s' [%u]\n", cmd, pid);
 663                         kill(pid, SIGKILL);
 664                 }
 665
 666                 if (pfd[0].revents & POLLIN) {
 667                         struct signalfd_siginfo fdsi;
 668                         int status;
 669                         ssize_t size;
 670
 671                         size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 672                         if (size != sizeof(struct signalfd_siginfo))
 673                                 continue;
 674
 675                         switch (fdsi.ssi_signo) {
 676                         case SIGTERM:
 677                                 event->sigterm = true;
 678                                 break;
 679                         case SIGCHLD:
 680                                 if (waitpid(pid, &status, WNOHANG) < 0)
 681                                         break;
 682                                 if (WIFEXITED(status)) {
 683                                         info(udev, "'%s' [%u] exit with return code %i\n", cmd, pid, WEXITSTATUS(status));
 684                                         if (WEXITSTATUS(status) != 0)
 685                                                 err = -1;
 686                                 } else if (WIFSIGNALED(status)) {
 687                                         err(udev, "'%s' [%u] terminated by signal %i (%s)\n", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 688                                         err = -1;
 689                                 } else if (WIFSTOPPED(status)) {
 690                                         err(udev, "'%s' [%u] stopped\n", cmd, pid);
 691                                         err = -1;
 692                                 } else if (WIFCONTINUED(status)) {
 693                                         err(udev, "'%s' [%u] continued\n", cmd, pid);
 694                                         err = -1;
 695                                 } else {
 696                                         err(udev, "'%s' [%u] exit with status 0x%04x\n", cmd, pid, status);
 697                                         err = -1;
 698                                 }
 699                                 pid = 0;
 700                                 break;
 701                         }
 702                 }
 703         }
 704 out:
 705         return err;
 706 }
 707
 708 int udev_event_spawn(struct udev_event *event,
 709                      const char *cmd, char **envp, const sigset_t *sigmask,
 710                      char *result, size_t ressize)
 711 {
 712         struct udev *udev = event->udev;
 713         int outpipe[2] = {-1, -1};
 714         int errpipe[2] = {-1, -1};
 715         pid_t pid;
 716         char arg[UTIL_PATH_SIZE];
 717         char program[UTIL_PATH_SIZE];
 718         char *argv[((sizeof(arg) + 1) / 2) + 1];
 719         int i;
 720         int err = 0;
 721
 722         /* build argv from command */
 723         util_strscpy(arg, sizeof(arg), cmd);
 724         i = 0;
 725         if (strchr(arg, ' ') != NULL) {
 726                 char *pos = arg;
 727
 728                 while (pos != NULL && pos[0] != '\0') {
 729                         if (pos[0] == '\'') {
 730                                 /* do not separate quotes */
 731                                 pos++;
 732                                 argv[i] = strsep(&pos, "\'");
 733                                 if (pos != NULL)
 734                                         while (pos[0] == ' ')
 735                                                 pos++;
 736                         } else {
 737                                 argv[i] = strsep(&pos, " ");
 738                                 if (pos != NULL)
 739                                         while (pos[0] == ' ')
 740                                                 pos++;
 741                         }
 742                         dbg(udev, "arg[%i] '%s'\n", i, argv[i]);
 743                         i++;
 744                 }
 745                 argv[i] = NULL;
 746         } else {
 747                 argv[0] = arg;
 748                 argv[1] = NULL;
 749         }
 750
 751         /* pipes from child to parent */
 752         if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
 753                 if (pipe2(outpipe, O_NONBLOCK) != 0) {
 754                         err = -errno;
 755                         err(udev, "pipe failed: %m\n");
 756                         goto out;
 757                 }
 758         }
 759         if (udev_get_log_priority(udev) >= LOG_INFO) {
 760                 if (pipe2(errpipe, O_NONBLOCK) != 0) {
 761                         err = -errno;
 762                         err(udev, "pipe failed: %m\n");
 763                         goto out;
 764                 }
 765         }
 766
 767         /* allow programs in /lib/udev/ to be called without the path */
 768         if (argv[0][0] != '/') {
 769                 util_strscpyl(program, sizeof(program), LIBEXECDIR "/", argv[0], NULL);
 770                 argv[0] = program;
 771         }
 772
 773         pid = fork();
 774         switch(pid) {
 775         case 0:
 776                 /* child closes parent's ends of pipes */
 777                 if (outpipe[READ_END] >= 0) {
 778                         close(outpipe[READ_END]);
 779                         outpipe[READ_END] = -1;
 780                 }
 781                 if (errpipe[READ_END] >= 0) {
 782                         close(errpipe[READ_END]);
 783                         errpipe[READ_END] = -1;
 784                 }
 785
 786                 info(udev, "starting '%s'\n", cmd);
 787
 788                 err = spawn_exec(event, cmd, argv, envp, sigmask,
 789                                  outpipe[WRITE_END], errpipe[WRITE_END]);
 790
 791                 _exit(2 );
 792         case -1:
 793                 err(udev, "fork of '%s' failed: %m\n", cmd);
 794                 err = -1;
 795                 goto out;
 796         default:
 797                 /* parent closed child's ends of pipes */
 798                 if (outpipe[WRITE_END] >= 0) {
 799                         close(outpipe[WRITE_END]);
 800                         outpipe[WRITE_END] = -1;
 801                 }
 802                 if (errpipe[WRITE_END] >= 0) {
 803                         close(errpipe[WRITE_END]);
 804                         errpipe[WRITE_END] = -1;
 805                 }
 806
 807                 err = spawn_read(event, cmd,
 808                                  outpipe[READ_END], errpipe[READ_END],
 809                                  result, ressize);
 810
 811                 err = spawn_wait(event, cmd, pid);
 812         }
 813
 814 out:
 815         if (outpipe[READ_END] >= 0)
 816                 close(outpipe[READ_END]);
 817         if (outpipe[WRITE_END] >= 0)
 818                 close(outpipe[WRITE_END]);
 819         if (errpipe[READ_END] >= 0)
 820                 close(errpipe[READ_END]);
 821         if (errpipe[WRITE_END] >= 0)
 822                 close(errpipe[WRITE_END]);
 823         return err;
 824 }
 825
 826 static void rename_netif_kernel_log(struct ifreq ifr)
 827 {
 828         int klog;
 829         FILE *f;
 830
 831         klog = open("/dev/kmsg", O_WRONLY);
 832         if (klog < 0)
 833                 return;
 834
 835         f = fdopen(klog, "w");
 836         if (f == NULL) {
 837                 close(klog);
 838                 return;
 839         }
 840
 841         fprintf(f, "<30>udevd[%u]: renamed network interface %s to %s\n",
 842                 getpid(), ifr.ifr_name, ifr.ifr_newname);
 843         fclose(f);
 844 }
 845
 846 static int rename_netif(struct udev_event *event)
 847 {
 848         struct udev_device *dev = event->dev;
 849         int sk;
 850         struct ifreq ifr;
 851         int loop;
 852         int err;
 853
 854         info(event->udev, "changing net interface name from '%s' to '%s'\n",
 855              udev_device_get_sysname(dev), event->name);
 856
 857         sk = socket(PF_INET, SOCK_DGRAM, 0);
 858         if (sk < 0) {
 859                 err = -errno;
 860                 err(event->udev, "error opening socket: %m\n");
 861                 return err;
 862         }
 863
 864         memset(&ifr, 0x00, sizeof(struct ifreq));
 865         util_strscpy(ifr.ifr_name, IFNAMSIZ, udev_device_get_sysname(dev));
 866         util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
 867         err = ioctl(sk, SIOCSIFNAME, &ifr);
 868         if (err == 0) {
 869                 rename_netif_kernel_log(ifr);
 870                 goto out;
 871         }
 872
 873         /* keep trying if the destination interface name already exists */
 874         err = -errno;
 875         if (err != -EEXIST)
 876                 goto out;
 877
 878         /* free our own name, another process may wait for us */
 879         snprintf(ifr.ifr_newname, IFNAMSIZ, "rename%u", udev_device_get_ifindex(dev));
 880         err = ioctl(sk, SIOCSIFNAME, &ifr);
 881         if (err < 0) {
 882                 err = -errno;
 883                 goto out;
 884         }
 885
 886         /* log temporary name */
 887         rename_netif_kernel_log(ifr);
 888
 889         /* wait a maximum of 90 seconds for our target to become available */
 890         util_strscpy(ifr.ifr_name, IFNAMSIZ, ifr.ifr_newname);
 891         util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
 892         loop = 90 * 20;
 893         while (loop--) {
 894                 const struct timespec duration = { 0, 1000 * 1000 * 1000 / 20 };
 895
 896                 dbg(event->udev, "wait for netif '%s' to become free, loop=%i\n",
 897                     event->name, (90 * 20) - loop);
 898                 nanosleep(&duration, NULL);
 899
 900                 err = ioctl(sk, SIOCSIFNAME, &ifr);
 901                 if (err == 0) {
 902                         rename_netif_kernel_log(ifr);
 903                         break;
 904                 }
 905                 err = -errno;
 906                 if (err != -EEXIST)
 907                         break;
 908         }
 909
 910 out:
 911         if (err < 0)
 912                 err(event->udev, "error changing net interface name %s to %s: %m\n", ifr.ifr_name, ifr.ifr_newname);
 913         close(sk);
 914         return err;
 915 }
 916
 917 int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules, const sigset_t *sigmask)
 918 {
 919         struct udev_device *dev = event->dev;
 920         int err = 0;
 921
 922         if (udev_device_get_subsystem(dev) == NULL)
 923                 return -1;
 924
 925         if (strcmp(udev_device_get_action(dev), "remove") == 0) {
 926                 udev_device_read_db(dev, NULL);
 927                 udev_device_delete_db(dev);
 928                 udev_device_tag_index(dev, NULL, false);
 929
 930                 if (major(udev_device_get_devnum(dev)) != 0)
 931                         udev_watch_end(event->udev, dev);
 932
 933                 udev_rules_apply_to_event(rules, event, sigmask);
 934
 935                 if (major(udev_device_get_devnum(dev)) != 0)
 936                         err = udev_node_remove(dev);
 937         } else {
 938                 event->dev_db = udev_device_new_from_syspath(event->udev, udev_device_get_syspath(dev));
 939                 if (event->dev_db != NULL) {
 940                         udev_device_read_db(event->dev_db, NULL);
 941                         udev_device_set_info_loaded(event->dev_db);
 942
 943                         /* disable watch during event processing */
 944                         if (major(udev_device_get_devnum(dev)) != 0)
 945                                 udev_watch_end(event->udev, event->dev_db);
 946                 }
 947
 948                 udev_rules_apply_to_event(rules, event, sigmask);
 949
 950                 /* rename a new network interface, if needed */
 951                 if (udev_device_get_ifindex(dev) > 0 && strcmp(udev_device_get_action(dev), "add") == 0 &&
 952                     event->name != NULL && strcmp(event->name, udev_device_get_sysname(dev)) != 0) {
 953                         char syspath[UTIL_PATH_SIZE];
 954                         char *pos;
 955
 956                         err = rename_netif(event);
 957                         if (err == 0) {
 958                                 info(event->udev, "renamed netif to '%s'\n", event->name);
 959
 960                                 /* delete stale db file */
 961                                 udev_device_delete_db(dev);
 962                                 udev_device_tag_index(dev, NULL, false);
 963
 964                                 /* remember old name */
 965                                 udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
 966
 967                                 /* now change the devpath, because the kernel device name has changed */
 968                                 util_strscpy(syspath, sizeof(syspath), udev_device_get_syspath(dev));
 969                                 pos = strrchr(syspath, '/');
 970                                 if (pos != NULL) {
 971                                         pos++;
 972                                         util_strscpy(pos, sizeof(syspath) - (pos - syspath), event->name);
 973                                         udev_device_set_syspath(event->dev, syspath);
 974                                         udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
 975                                         info(event->udev, "changed devpath to '%s'\n", udev_device_get_devpath(dev));
 976                                 }
 977                         }
 978                 }
 979
 980                 if (major(udev_device_get_devnum(dev)) != 0) {
 981                         char filename[UTIL_PATH_SIZE];
 982
 983                         if (event->tmp_node != NULL) {
 984                                 info(event->udev, "cleanup temporary device node\n");
 985                                 util_unlink_secure(event->udev, event->tmp_node);
 986                                 free(event->tmp_node);
 987                                 event->tmp_node = NULL;
 988                         }
 989
 990                         /* no rule, use kernel provided name */
 991                         if (event->name == NULL) {
 992                                 if (udev_device_get_knodename(dev) != NULL) {
 993                                         event->name = strdup(udev_device_get_knodename(dev));
 994                                         info(event->udev, "no node name set, will use kernel supplied name '%s'\n", event->name);
 995                                 } else {
 996                                         event->name = strdup(udev_device_get_sysname(event->dev));
 997                                         info(event->udev, "no node name set, will use device name '%s'\n", event->name);
 998                                 }
 999                         }
1000
1001                         if (event->name == NULL || event->name[0] == '\0') {
1002                                 udev_device_delete_db(dev);
1003                                 udev_device_tag_index(dev, NULL, false);
1004                                 udev_device_unref(event->dev_db);
1005                                 err = -ENOMEM;
1006                                 err(event->udev, "no node name, something went wrong, ignoring\n");
1007                                 goto out;
1008                         }
1009
1010                         if (udev_device_get_knodename(dev) != NULL && strcmp(udev_device_get_knodename(dev), event->name) != 0)
1011                                 err(event->udev, "kernel-provided name '%s' and NAME= '%s' disagree, "
1012                                     "please use SYMLINK+= or change the kernel to provide the proper name\n",
1013                                     udev_device_get_knodename(dev), event->name);
1014
1015                         /* set device node name */
1016                         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(event->udev), "/", event->name, NULL);
1017                         udev_device_set_devnode(dev, filename);
1018
1019                         /* remove/update possible left-over symlinks from old database entry */
1020                         if (event->dev_db != NULL)
1021                                 udev_node_update_old_links(dev, event->dev_db);
1022
1023                         if (!event->mode_set) {
1024                                 if (udev_device_get_devnode_mode(dev) > 0) {
1025                                         /* kernel supplied value */
1026                                         event->mode = udev_device_get_devnode_mode(dev);
1027                                 } else if (event->gid > 0) {
1028                                         /* default 0660 if a group is assigned */
1029                                         event->mode = 0660;
1030                                 } else {
1031                                         /* default 0600 */
1032                                         event->mode = 0600;
1033                                 }
1034                         }
1035
1036                         err = udev_node_add(dev, event->mode, event->uid, event->gid);
1037                 }
1038
1039                 /* preserve old, or get new initialization timestamp */
1040                 if (event->dev_db != NULL && udev_device_get_usec_initialized(event->dev_db) > 0)
1041                         udev_device_set_usec_initialized(event->dev, udev_device_get_usec_initialized(event->dev_db));
1042                 else
1043                         udev_device_set_usec_initialized(event->dev, now_usec());
1044
1045                 /* (re)write database file */
1046                 udev_device_update_db(dev);
1047                 udev_device_tag_index(dev, event->dev_db, true);
1048                 udev_device_set_is_initialized(dev);
1049
1050                 udev_device_unref(event->dev_db);
1051                 event->dev_db = NULL;
1052         }
1053 out:
1054         return err;
1055 }
1056
1057 int udev_event_execute_run(struct udev_event *event, const sigset_t *sigmask)
1058 {
1059         struct udev_list_entry *list_entry;
1060         int err = 0;
1061
1062         dbg(event->udev, "executing run list\n");
1063         udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
1064                 const char *cmd = udev_list_entry_get_name(list_entry);
1065
1066                 if (strncmp(cmd, "socket:", strlen("socket:")) == 0) {
1067                         struct udev_monitor *monitor;
1068
1069                         monitor = udev_monitor_new_from_socket(event->udev, &cmd[strlen("socket:")]);
1070                         if (monitor == NULL)
1071                                 continue;
1072                         udev_monitor_send_device(monitor, NULL, event->dev);
1073                         udev_monitor_unref(monitor);
1074                 } else {
1075                         char program[UTIL_PATH_SIZE];
1076                         char **envp;
1077
1078                         if (event->exec_delay > 0) {
1079                                 info(event->udev, "delay execution of '%s'\n", program);
1080                                 sleep(event->exec_delay);
1081                         }
1082
1083                         udev_event_apply_format(event, cmd, program, sizeof(program));
1084                         envp = udev_device_get_properties_envp(event->dev);
1085                         if (udev_event_spawn(event, program, envp, sigmask, NULL, 0) < 0) {
1086                                 if (udev_list_entry_get_num(list_entry))
1087                                         err = -1;
1088                         }
1089                 }
1090         }
1091         return err;
1092 }