src/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         dbg(event->udev, "allocated event %p\n", event);
  54         return event;
  55 }
  56
  57 void udev_event_unref(struct udev_event *event)
  58 {
  59         if (event == NULL)
  60                 return;
  61         udev_list_cleanup(&event->run_list);
  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_DEVNODE,
  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 = "devnode",        .fmt = 'N',        .type = SUBST_DEVNODE },
  96                 { .name = "tempnode",        .fmt = 'N',        .type = SUBST_DEVNODE },
  97                 { .name = "attr",        .fmt = 's',        .type = SUBST_ATTR },
  98                 { .name = "sysfs",        .fmt = 's',        .type = SUBST_ATTR },
  99                 { .name = "env",        .fmt = 'E',        .type = SUBST_ENV },
 100                 { .name = "kernel",        .fmt = 'k',        .type = SUBST_KERNEL },
 101                 { .name = "number",        .fmt = 'n',        .type = SUBST_KERNEL_NUMBER },
 102                 { .name = "driver",        .fmt = 'd',        .type = SUBST_DRIVER },
 103                 { .name = "devpath",        .fmt = 'p',        .type = SUBST_DEVPATH },
 104                 { .name = "id",                .fmt = 'b',        .type = SUBST_ID },
 105                 { .name = "major",        .fmt = 'M',        .type = SUBST_MAJOR },
 106                 { .name = "minor",        .fmt = 'm',        .type = SUBST_MINOR },
 107                 { .name = "result",        .fmt = 'c',        .type = SUBST_RESULT },
 108                 { .name = "parent",        .fmt = 'P',        .type = SUBST_PARENT },
 109                 { .name = "name",        .fmt = 'D',        .type = SUBST_NAME },
 110                 { .name = "links",        .fmt = 'L',        .type = SUBST_LINKS },
 111                 { .name = "root",        .fmt = 'r',        .type = SUBST_ROOT },
 112                 { .name = "sys",        .fmt = 'S',        .type = SUBST_SYS },
 113         };
 114         const char *from;
 115         char *s;
 116         size_t l;
 117
 118         from = src;
 119         s = dest;
 120         l = size;
 121
 122         for (;;) {
 123                 enum subst_type type = SUBST_UNKNOWN;
 124                 char attrbuf[UTIL_PATH_SIZE];
 125                 char *attr = NULL;
 126
 127                 while (from[0] != '\0') {
 128                         if (from[0] == '$') {
 129                                 /* substitute named variable */
 130                                 unsigned int i;
 131
 132                                 if (from[1] == '$') {
 133                                         from++;
 134                                         goto copy;
 135                                 }
 136
 137                                 for (i = 0; i < ARRAY_SIZE(map); i++) {
 138                                         if (strncmp(&from[1], map[i].name, strlen(map[i].name)) == 0) {
 139                                                 type = map[i].type;
 140                                                 from += strlen(map[i].name)+1;
 141                                                 dbg(event->udev, "will substitute format name '%s'\n", map[i].name);
 142                                                 goto subst;
 143                                         }
 144                                 }
 145                         } else if (from[0] == '%') {
 146                                 /* substitute format char */
 147                                 unsigned int i;
 148
 149                                 if (from[1] == '%') {
 150                                         from++;
 151                                         goto copy;
 152                                 }
 153
 154                                 for (i = 0; i < ARRAY_SIZE(map); i++) {
 155                                         if (from[1] == map[i].fmt) {
 156                                                 type = map[i].type;
 157                                                 from += 2;
 158                                                 dbg(event->udev, "will substitute format char '%c'\n", map[i].fmt);
 159                                                 goto subst;
 160                                         }
 161                                 }
 162                         }
 163 copy:
 164                         /* copy char */
 165                         if (l == 0)
 166                                 goto out;
 167                         s[0] = from[0];
 168                         from++;
 169                         s++;
 170                         l--;
 171                 }
 172
 173                 goto out;
 174 subst:
 175                 /* extract possible $format{attr} */
 176                 if (from[0] == '{') {
 177                         unsigned int i;
 178
 179                         from++;
 180                         for (i = 0; from[i] != '}'; i++) {
 181                                 if (from[i] == '\0') {
 182                                         err(event->udev, "missing closing brace for format '%s'\n", src);
 183                                         goto out;
 184                                 }
 185                         }
 186                         if (i >= sizeof(attrbuf))
 187                                 goto out;
 188                         memcpy(attrbuf, from, i);
 189                         attrbuf[i] = '\0';
 190                         from += i+1;
 191                         attr = attrbuf;
 192                 } else {
 193                         attr = NULL;
 194                 }
 195
 196                 switch (type) {
 197                 case SUBST_DEVPATH:
 198                         l = util_strpcpy(&s, l, udev_device_get_devpath(dev));
 199                         dbg(event->udev, "substitute devpath '%s'\n", udev_device_get_devpath(dev));
 200                         break;
 201                 case SUBST_KERNEL:
 202                         l = util_strpcpy(&s, l, udev_device_get_sysname(dev));
 203                         dbg(event->udev, "substitute kernel name '%s'\n", udev_device_get_sysname(dev));
 204                         break;
 205                 case SUBST_KERNEL_NUMBER:
 206                         if (udev_device_get_sysnum(dev) == NULL)
 207                                 break;
 208                         l = util_strpcpy(&s, l, udev_device_get_sysnum(dev));
 209                         dbg(event->udev, "substitute kernel number '%s'\n", udev_device_get_sysnum(dev));
 210                         break;
 211                 case SUBST_ID:
 212                         if (event->dev_parent == NULL)
 213                                 break;
 214                         l = util_strpcpy(&s, l, udev_device_get_sysname(event->dev_parent));
 215                         dbg(event->udev, "substitute id '%s'\n", udev_device_get_sysname(event->dev_parent));
 216                         break;
 217                 case SUBST_DRIVER: {
 218                         const char *driver;
 219
 220                         if (event->dev_parent == NULL)
 221                                 break;
 222
 223                         driver = udev_device_get_driver(event->dev_parent);
 224                         if (driver == NULL)
 225                                 break;
 226                         l = util_strpcpy(&s, l, driver);
 227                         dbg(event->udev, "substitute driver '%s'\n", driver);
 228                         break;
 229                 }
 230                 case SUBST_MAJOR: {
 231                         char num[UTIL_PATH_SIZE];
 232
 233                         sprintf(num, "%d", major(udev_device_get_devnum(dev)));
 234                         l = util_strpcpy(&s, l, num);
 235                         dbg(event->udev, "substitute major number '%s'\n", num);
 236                         break;
 237                 }
 238                 case SUBST_MINOR: {
 239                         char num[UTIL_PATH_SIZE];
 240
 241                         sprintf(num, "%d", minor(udev_device_get_devnum(dev)));
 242                         l = util_strpcpy(&s, l, num);
 243                         dbg(event->udev, "substitute minor number '%s'\n", num);
 244                         break;
 245                 }
 246                 case SUBST_RESULT: {
 247                         char *rest;
 248                         int i;
 249
 250                         if (event->program_result == NULL)
 251                                 break;
 252                         /* get part part of the result string */
 253                         i = 0;
 254                         if (attr != NULL)
 255                                 i = strtoul(attr, &rest, 10);
 256                         if (i > 0) {
 257                                 char result[UTIL_PATH_SIZE];
 258                                 char tmp[UTIL_PATH_SIZE];
 259                                 char *cpos;
 260
 261                                 dbg(event->udev, "request part #%d of result string\n", i);
 262                                 util_strscpy(result, sizeof(result), event->program_result);
 263                                 cpos = result;
 264                                 while (--i) {
 265                                         while (cpos[0] != '\0' && !isspace(cpos[0]))
 266                                                 cpos++;
 267                                         while (isspace(cpos[0]))
 268                                                 cpos++;
 269                                 }
 270                                 if (i > 0) {
 271                                         err(event->udev, "requested part of result string not found\n");
 272                                         break;
 273                                 }
 274                                 util_strscpy(tmp, sizeof(tmp), cpos);
 275                                 /* %{2+}c copies the whole string from the second part on */
 276                                 if (rest[0] != '+') {
 277                                         cpos = strchr(tmp, ' ');
 278                                         if (cpos)
 279                                                 cpos[0] = '\0';
 280                                 }
 281                                 l = util_strpcpy(&s, l, tmp);
 282                                 dbg(event->udev, "substitute part of result string '%s'\n", tmp);
 283                         } else {
 284                                 l = util_strpcpy(&s, l, event->program_result);
 285                                 dbg(event->udev, "substitute result string '%s'\n", event->program_result);
 286                         }
 287                         break;
 288                 }
 289                 case SUBST_ATTR: {
 290                         const char *value = NULL;
 291                         char vbuf[UTIL_NAME_SIZE];
 292                         size_t len;
 293                         int count;
 294
 295                         if (attr == NULL) {
 296                                 err(event->udev, "missing file parameter for attr\n");
 297                                 break;
 298                         }
 299
 300                         /* try to read the value specified by "[dmi/id]product_name" */
 301                         if (util_resolve_subsys_kernel(event->udev, attr, vbuf, sizeof(vbuf), 1) == 0)
 302                                 value = vbuf;
 303
 304                         /* try to read the attribute the device */
 305                         if (value == NULL)
 306                                 value = udev_device_get_sysattr_value(event->dev, attr);
 307
 308                         /* try to read the attribute of the parent device, other matches have selected */
 309                         if (value == NULL && event->dev_parent != NULL && event->dev_parent != event->dev)
 310                                 value = udev_device_get_sysattr_value(event->dev_parent, attr);
 311
 312                         if (value == NULL)
 313                                 break;
 314
 315                         /* strip trailing whitespace, and replace unwanted characters */
 316                         if (value != vbuf)
 317                                 util_strscpy(vbuf, sizeof(vbuf), value);
 318                         len = strlen(vbuf);
 319                         while (len > 0 && isspace(vbuf[--len]))
 320                                 vbuf[len] = '\0';
 321                         count = util_replace_chars(vbuf, UDEV_ALLOWED_CHARS_INPUT);
 322                         if (count > 0)
 323                                 info(event->udev, "%i character(s) replaced\n" , count);
 324                         l = util_strpcpy(&s, l, vbuf);
 325                         dbg(event->udev, "substitute sysfs value '%s'\n", vbuf);
 326                         break;
 327                 }
 328                 case SUBST_PARENT: {
 329                         struct udev_device *dev_parent;
 330                         const char *devnode;
 331
 332                         dev_parent = udev_device_get_parent(event->dev);
 333                         if (dev_parent == NULL)
 334                                 break;
 335                         devnode = udev_device_get_devnode(dev_parent);
 336                         if (devnode != NULL) {
 337                                 size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
 338
 339                                 l = util_strpcpy(&s, l, &devnode[devlen]);
 340                                 dbg(event->udev, "found parent '%s', got node name '%s'\n",
 341                                     udev_device_get_syspath(dev_parent), &devnode[devlen]);
 342                         }
 343                         break;
 344                 }
 345                 case SUBST_DEVNODE:
 346                         if (udev_device_get_devnode(dev) != NULL)
 347                                 l = util_strpcpy(&s, l, udev_device_get_devnode(dev));
 348                         break;
 349                 case SUBST_NAME: {
 350                         if (event->name != NULL) {
 351                                 l = util_strpcpy(&s, l, event->name);
 352                                 dbg(event->udev, "substitute custom node name '%s'\n", event->name);
 353                         } else if (udev_device_get_devnode(dev) != NULL) {
 354                                 size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
 355
 356                                 l = util_strpcpy(&s, l, &udev_device_get_devnode(dev)[devlen]);
 357                                 dbg(event->udev, "substitute node name'%s'\n", &udev_device_get_devnode(dev)[devlen]);
 358                         } else {
 359                                 l = util_strpcpy(&s, l, udev_device_get_sysname(dev));
 360                                 dbg(event->udev, "substitute device name'%s'\n", udev_device_get_sysname(dev));
 361                         }
 362                         break;
 363                 }
 364                 case SUBST_LINKS: {
 365                         size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
 366                         struct udev_list_entry *list_entry;
 367
 368                         list_entry = udev_device_get_devlinks_list_entry(dev);
 369                         if (list_entry == NULL)
 370                                 break;
 371                         l = util_strpcpy(&s, l, &udev_list_entry_get_name(list_entry)[devlen]);
 372                         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
 373                                 l = util_strpcpyl(&s, l, " ", &udev_list_entry_get_name(list_entry)[devlen], NULL);
 374                         break;
 375                 }
 376                 case SUBST_ROOT:
 377                         l = util_strpcpy(&s, l, udev_get_dev_path(event->udev));
 378                         dbg(event->udev, "substitute udev_root '%s'\n", udev_get_dev_path(event->udev));
 379                         break;
 380                 case SUBST_SYS:
 381                         l = util_strpcpy(&s, l, udev_get_sys_path(event->udev));
 382                         dbg(event->udev, "substitute sys_path '%s'\n", udev_get_sys_path(event->udev));
 383                         break;
 384                 case SUBST_ENV:
 385                         if (attr == NULL) {
 386                                 dbg(event->udev, "missing attribute\n");
 387                                 break;
 388                         } else {
 389                                 const char *value;
 390
 391                                 value = udev_device_get_property_value(event->dev, attr);
 392                                 if (value == NULL)
 393                                         break;
 394                                 dbg(event->udev, "substitute env '%s=%s'\n", attr, value);
 395                                 l = util_strpcpy(&s, l, value);
 396                                 break;
 397                         }
 398                 default:
 399                         err(event->udev, "unknown substitution type=%i\n", type);
 400                         break;
 401                 }
 402         }
 403
 404 out:
 405         s[0] = '\0';
 406         dbg(event->udev, "'%s' -> '%s' (%zu)\n", src, dest, l);
 407         return l;
 408 }
 409
 410 static int spawn_exec(struct udev_event *event,
 411                       const char *cmd, char *const argv[], char **envp, const sigset_t *sigmask,
 412                       int fd_stdout, int fd_stderr)
 413 {
 414         struct udev *udev = event->udev;
 415         int err;
 416         int fd;
 417
 418         /* discard child output or connect to pipe */
 419         fd = open("/dev/null", O_RDWR);
 420         if (fd >= 0) {
 421                 dup2(fd, STDIN_FILENO);
 422                 if (fd_stdout < 0)
 423                         dup2(fd, STDOUT_FILENO);
 424                 if (fd_stderr < 0)
 425                         dup2(fd, STDERR_FILENO);
 426                 close(fd);
 427         } else {
 428                 err(udev, "open /dev/null failed: %m\n");
 429         }
 430
 431         /* connect pipes to std{out,err} */
 432         if (fd_stdout >= 0) {
 433                 dup2(fd_stdout, STDOUT_FILENO);
 434                         close(fd_stdout);
 435         }
 436         if (fd_stderr >= 0) {
 437                 dup2(fd_stderr, STDERR_FILENO);
 438                 close(fd_stderr);
 439         }
 440
 441         /* terminate child in case parent goes away */
 442         prctl(PR_SET_PDEATHSIG, SIGTERM);
 443
 444         /* restore original udev sigmask before exec */
 445         if (sigmask)
 446                 sigprocmask(SIG_SETMASK, sigmask, NULL);
 447
 448         execve(argv[0], argv, envp);
 449
 450         /* exec failed */
 451         err = -errno;
 452         err(udev, "failed to execute '%s' '%s': %m\n", argv[0], cmd);
 453         return err;
 454 }
 455
 456 static void spawn_read(struct udev_event *event,
 457                       const char *cmd,
 458                       int fd_stdout, int fd_stderr,
 459                       char *result, size_t ressize)
 460 {
 461         struct udev *udev = event->udev;
 462         size_t respos = 0;
 463         int fd_ep = -1;
 464         struct epoll_event ep_outpipe, ep_errpipe;
 465
 466         /* read from child if requested */
 467         if (fd_stdout < 0 && fd_stderr < 0)
 468                 return;
 469
 470         fd_ep = epoll_create1(EPOLL_CLOEXEC);
 471         if (fd_ep < 0) {
 472                 err(udev, "error creating epoll fd: %m\n");
 473                 goto out;
 474         }
 475
 476         if (fd_stdout >= 0) {
 477                 memset(&ep_outpipe, 0, sizeof(struct epoll_event));
 478                 ep_outpipe.events = EPOLLIN;
 479                 ep_outpipe.data.ptr = &fd_stdout;
 480                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe) < 0) {
 481                         err(udev, "fail to add fd to epoll: %m\n");
 482                         goto out;
 483                 }
 484         }
 485
 486         if (fd_stderr >= 0) {
 487                 memset(&ep_errpipe, 0, sizeof(struct epoll_event));
 488                 ep_errpipe.events = EPOLLIN;
 489                 ep_errpipe.data.ptr = &fd_stderr;
 490                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe) < 0) {
 491                         err(udev, "fail to add fd to epoll: %m\n");
 492                         goto out;
 493                 }
 494         }
 495
 496         /* read child output */
 497         while (fd_stdout >= 0 || fd_stderr >= 0) {
 498                 int timeout;
 499                 int fdcount;
 500                 struct epoll_event ev[4];
 501                 int i;
 502
 503                 if (event->timeout_usec > 0) {
 504                         unsigned long long age_usec;
 505
 506                         age_usec = now_usec() - event->birth_usec;
 507                         if (age_usec >= event->timeout_usec) {
 508                                 err(udev, "timeout '%s'\n", cmd);
 509                                 goto out;
 510                         }
 511                         timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
 512                 } else {
 513                         timeout = -1;
 514                 }
 515
 516                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
 517                 if (fdcount < 0) {
 518                         if (errno == EINTR)
 519                                 continue;
 520                         err(udev, "failed to poll: %m\n");
 521                         goto out;
 522                 }
 523                 if (fdcount == 0) {
 524                         err(udev, "timeout '%s'\n", cmd);
 525                         goto out;
 526                 }
 527
 528                 for (i = 0; i < fdcount; i++) {
 529                         int *fd = (int *)ev[i].data.ptr;
 530
 531                         if (ev[i].events & EPOLLIN) {
 532                                 ssize_t count;
 533                                 char buf[4096];
 534
 535                                 count = read(*fd, buf, sizeof(buf)-1);
 536                                 if (count <= 0)
 537                                         continue;
 538                                 buf[count] = '\0';
 539
 540                                 /* store stdout result */
 541                                 if (result != NULL && *fd == fd_stdout) {
 542                                         if (respos + count < ressize) {
 543                                                 memcpy(&result[respos], buf, count);
 544                                                 respos += count;
 545                                         } else {
 546                                                 err(udev, "'%s' ressize %zd too short\n", cmd, ressize);
 547                                         }
 548                                 }
 549
 550                                 /* log debug output only if we watch stderr */
 551                                 if (fd_stderr >= 0) {
 552                                         char *pos;
 553                                         char *line;
 554
 555                                         pos = buf;
 556                                         while ((line = strsep(&pos, "\n"))) {
 557                                                 if (pos != NULL || line[0] != '\0')
 558                                                         info(udev, "'%s'(%s) '%s'\n", cmd, *fd == fd_stdout ? "out" : "err" , line);
 559                                         }
 560                                 }
 561                         } else if (ev[i].events & EPOLLHUP) {
 562                                 if (epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL) < 0) {
 563                                         err(udev, "failed to remove fd from epoll: %m\n");
 564                                         goto out;
 565                                 }
 566                                 *fd = -1;
 567                         }
 568                 }
 569         }
 570
 571         /* return the child's stdout string */
 572         if (result != NULL) {
 573                 result[respos] = '\0';
 574                 dbg(udev, "result='%s'\n", result);
 575         }
 576 out:
 577         if (fd_ep >= 0)
 578                 close(fd_ep);
 579 }
 580
 581 static int spawn_wait(struct udev_event *event, const char *cmd, pid_t pid)
 582 {
 583         struct udev *udev = event->udev;
 584         struct pollfd pfd[1];
 585         int err = 0;
 586
 587         pfd[0].events = POLLIN;
 588         pfd[0].fd = event->fd_signal;
 589
 590         while (pid > 0) {
 591                 int timeout;
 592                 int fdcount;
 593
 594                 if (event->timeout_usec > 0) {
 595                         unsigned long long age_usec;
 596
 597                         age_usec = now_usec() - event->birth_usec;
 598                         if (age_usec >= event->timeout_usec)
 599                                 timeout = 1000;
 600                         else
 601                                 timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
 602                 } else {
 603                         timeout = -1;
 604                 }
 605
 606                 fdcount = poll(pfd, 1, timeout);
 607                 if (fdcount < 0) {
 608                         if (errno == EINTR)
 609                                 continue;
 610                         err = -errno;
 611                         err(udev, "failed to poll: %m\n");
 612                         goto out;
 613                 }
 614                 if (fdcount == 0) {
 615                         err(udev, "timeout: killing '%s' [%u]\n", cmd, pid);
 616                         kill(pid, SIGKILL);
 617                 }
 618
 619                 if (pfd[0].revents & POLLIN) {
 620                         struct signalfd_siginfo fdsi;
 621                         int status;
 622                         ssize_t size;
 623
 624                         size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
 625                         if (size != sizeof(struct signalfd_siginfo))
 626                                 continue;
 627
 628                         switch (fdsi.ssi_signo) {
 629                         case SIGTERM:
 630                                 event->sigterm = true;
 631                                 break;
 632                         case SIGCHLD:
 633                                 if (waitpid(pid, &status, WNOHANG) < 0)
 634                                         break;
 635                                 if (WIFEXITED(status)) {
 636                                         info(udev, "'%s' [%u] exit with return code %i\n", cmd, pid, WEXITSTATUS(status));
 637                                         if (WEXITSTATUS(status) != 0)
 638                                                 err = -1;
 639                                 } else if (WIFSIGNALED(status)) {
 640                                         err(udev, "'%s' [%u] terminated by signal %i (%s)\n", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
 641                                         err = -1;
 642                                 } else if (WIFSTOPPED(status)) {
 643                                         err(udev, "'%s' [%u] stopped\n", cmd, pid);
 644                                         err = -1;
 645                                 } else if (WIFCONTINUED(status)) {
 646                                         err(udev, "'%s' [%u] continued\n", cmd, pid);
 647                                         err = -1;
 648                                 } else {
 649                                         err(udev, "'%s' [%u] exit with status 0x%04x\n", cmd, pid, status);
 650                                         err = -1;
 651                                 }
 652                                 pid = 0;
 653                                 break;
 654                         }
 655                 }
 656         }
 657 out:
 658         return err;
 659 }
 660
 661 int udev_build_argv(struct udev *udev, char *cmd, int *argc, char *argv[])
 662 {
 663         int i = 0;
 664         char *pos;
 665
 666         if (strchr(cmd, ' ') == NULL) {
 667                 argv[i++] = cmd;
 668                 goto out;
 669         }
 670
 671         pos = cmd;
 672         while (pos != NULL && pos[0] != '\0') {
 673                 if (pos[0] == '\'') {
 674                         /* do not separate quotes */
 675                         pos++;
 676                         argv[i] = strsep(&pos, "\'");
 677                         if (pos != NULL)
 678                                 while (pos[0] == ' ')
 679                                         pos++;
 680                 } else {
 681                         argv[i] = strsep(&pos, " ");
 682                         if (pos != NULL)
 683                                 while (pos[0] == ' ')
 684                                         pos++;
 685                 }
 686                 dbg(udev, "argv[%i] '%s'\n", i, argv[i]);
 687                 i++;
 688         }
 689 out:
 690         argv[i] = NULL;
 691         if (argc)
 692                 *argc = i;
 693         return 0;
 694 }
 695
 696 int udev_event_spawn(struct udev_event *event,
 697                      const char *cmd, char **envp, const sigset_t *sigmask,
 698                      char *result, size_t ressize)
 699 {
 700         struct udev *udev = event->udev;
 701         int outpipe[2] = {-1, -1};
 702         int errpipe[2] = {-1, -1};
 703         pid_t pid;
 704         char arg[UTIL_PATH_SIZE];
 705         char *argv[128];
 706         char program[UTIL_PATH_SIZE];
 707         int err = 0;
 708
 709         util_strscpy(arg, sizeof(arg), cmd);
 710         udev_build_argv(event->udev, arg, NULL, argv);
 711
 712         /* pipes from child to parent */
 713         if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
 714                 if (pipe2(outpipe, O_NONBLOCK) != 0) {
 715                         err = -errno;
 716                         err(udev, "pipe failed: %m\n");
 717                         goto out;
 718                 }
 719         }
 720         if (udev_get_log_priority(udev) >= LOG_INFO) {
 721                 if (pipe2(errpipe, O_NONBLOCK) != 0) {
 722                         err = -errno;
 723                         err(udev, "pipe failed: %m\n");
 724                         goto out;
 725                 }
 726         }
 727
 728         /* allow programs in /usr/lib/udev/ to be called without the path */
 729         if (argv[0][0] != '/') {
 730                 util_strscpyl(program, sizeof(program), PKGLIBEXECDIR "/", argv[0], NULL);
 731                 argv[0] = program;
 732         }
 733
 734         pid = fork();
 735         switch(pid) {
 736         case 0:
 737                 /* child closes parent's ends of pipes */
 738                 if (outpipe[READ_END] >= 0) {
 739                         close(outpipe[READ_END]);
 740                         outpipe[READ_END] = -1;
 741                 }
 742                 if (errpipe[READ_END] >= 0) {
 743                         close(errpipe[READ_END]);
 744                         errpipe[READ_END] = -1;
 745                 }
 746
 747                 info(udev, "starting '%s'\n", cmd);
 748
 749                 err = spawn_exec(event, cmd, argv, envp, sigmask,
 750                                  outpipe[WRITE_END], errpipe[WRITE_END]);
 751
 752                 _exit(2 );
 753         case -1:
 754                 err(udev, "fork of '%s' failed: %m\n", cmd);
 755                 err = -1;
 756                 goto out;
 757         default:
 758                 /* parent closed child's ends of pipes */
 759                 if (outpipe[WRITE_END] >= 0) {
 760                         close(outpipe[WRITE_END]);
 761                         outpipe[WRITE_END] = -1;
 762                 }
 763                 if (errpipe[WRITE_END] >= 0) {
 764                         close(errpipe[WRITE_END]);
 765                         errpipe[WRITE_END] = -1;
 766                 }
 767
 768                 spawn_read(event, cmd,
 769                          outpipe[READ_END], errpipe[READ_END],
 770                          result, ressize);
 771
 772                 err = spawn_wait(event, cmd, pid);
 773         }
 774
 775 out:
 776         if (outpipe[READ_END] >= 0)
 777                 close(outpipe[READ_END]);
 778         if (outpipe[WRITE_END] >= 0)
 779                 close(outpipe[WRITE_END]);
 780         if (errpipe[READ_END] >= 0)
 781                 close(errpipe[READ_END]);
 782         if (errpipe[WRITE_END] >= 0)
 783                 close(errpipe[WRITE_END]);
 784         return err;
 785 }
 786
 787 static void rename_netif_kernel_log(struct ifreq ifr)
 788 {
 789         int klog;
 790         FILE *f;
 791
 792         klog = open("/dev/kmsg", O_WRONLY);
 793         if (klog < 0)
 794                 return;
 795
 796         f = fdopen(klog, "w");
 797         if (f == NULL) {
 798                 close(klog);
 799                 return;
 800         }
 801
 802         fprintf(f, "<30>udevd[%u]: renamed network interface %s to %s\n",
 803                 getpid(), ifr.ifr_name, ifr.ifr_newname);
 804         fclose(f);
 805 }
 806
 807 static int rename_netif(struct udev_event *event)
 808 {
 809         struct udev_device *dev = event->dev;
 810         int sk;
 811         struct ifreq ifr;
 812         int loop;
 813         int err;
 814
 815         info(event->udev, "changing net interface name from '%s' to '%s'\n",
 816              udev_device_get_sysname(dev), event->name);
 817
 818         sk = socket(PF_INET, SOCK_DGRAM, 0);
 819         if (sk < 0) {
 820                 err = -errno;
 821                 err(event->udev, "error opening socket: %m\n");
 822                 return err;
 823         }
 824
 825         memset(&ifr, 0x00, sizeof(struct ifreq));
 826         util_strscpy(ifr.ifr_name, IFNAMSIZ, udev_device_get_sysname(dev));
 827         util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
 828         err = ioctl(sk, SIOCSIFNAME, &ifr);
 829         if (err == 0) {
 830                 rename_netif_kernel_log(ifr);
 831                 goto out;
 832         }
 833
 834         /* keep trying if the destination interface name already exists */
 835         err = -errno;
 836         if (err != -EEXIST)
 837                 goto out;
 838
 839         /* free our own name, another process may wait for us */
 840         snprintf(ifr.ifr_newname, IFNAMSIZ, "rename%u", udev_device_get_ifindex(dev));
 841         err = ioctl(sk, SIOCSIFNAME, &ifr);
 842         if (err < 0) {
 843                 err = -errno;
 844                 goto out;
 845         }
 846
 847         /* log temporary name */
 848         rename_netif_kernel_log(ifr);
 849
 850         /* wait a maximum of 90 seconds for our target to become available */
 851         util_strscpy(ifr.ifr_name, IFNAMSIZ, ifr.ifr_newname);
 852         util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
 853         loop = 90 * 20;
 854         while (loop--) {
 855                 const struct timespec duration = { 0, 1000 * 1000 * 1000 / 20 };
 856
 857                 dbg(event->udev, "wait for netif '%s' to become free, loop=%i\n",
 858                     event->name, (90 * 20) - loop);
 859                 nanosleep(&duration, NULL);
 860
 861                 err = ioctl(sk, SIOCSIFNAME, &ifr);
 862                 if (err == 0) {
 863                         rename_netif_kernel_log(ifr);
 864                         break;
 865                 }
 866                 err = -errno;
 867                 if (err != -EEXIST)
 868                         break;
 869         }
 870
 871 out:
 872         if (err < 0)
 873                 err(event->udev, "error changing net interface name %s to %s: %m\n", ifr.ifr_name, ifr.ifr_newname);
 874         close(sk);
 875         return err;
 876 }
 877
 878 int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules, const sigset_t *sigmask)
 879 {
 880         struct udev_device *dev = event->dev;
 881         int err = 0;
 882
 883         if (udev_device_get_subsystem(dev) == NULL)
 884                 return -1;
 885
 886         if (strcmp(udev_device_get_action(dev), "remove") == 0) {
 887                 udev_device_read_db(dev, NULL);
 888                 udev_device_delete_db(dev);
 889                 udev_device_tag_index(dev, NULL, false);
 890
 891                 if (major(udev_device_get_devnum(dev)) != 0)
 892                         udev_watch_end(event->udev, dev);
 893
 894                 udev_rules_apply_to_event(rules, event, sigmask);
 895
 896                 if (major(udev_device_get_devnum(dev)) != 0)
 897                         udev_node_remove(dev);
 898         } else {
 899                 event->dev_db = udev_device_new_from_syspath(event->udev, udev_device_get_syspath(dev));
 900                 if (event->dev_db != NULL) {
 901                         udev_device_read_db(event->dev_db, NULL);
 902                         udev_device_set_info_loaded(event->dev_db);
 903
 904                         /* disable watch during event processing */
 905                         if (major(udev_device_get_devnum(dev)) != 0)
 906                                 udev_watch_end(event->udev, event->dev_db);
 907                 }
 908
 909                 udev_rules_apply_to_event(rules, event, sigmask);
 910
 911                 /* rename a new network interface, if needed */
 912                 if (udev_device_get_ifindex(dev) > 0 && strcmp(udev_device_get_action(dev), "add") == 0 &&
 913                     event->name != NULL && strcmp(event->name, udev_device_get_sysname(dev)) != 0) {
 914                         char syspath[UTIL_PATH_SIZE];
 915                         char *pos;
 916
 917                         err = rename_netif(event);
 918                         if (err == 0) {
 919                                 info(event->udev, "renamed netif to '%s'\n", event->name);
 920
 921                                 /* remember old name */
 922                                 udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
 923
 924                                 /* now change the devpath, because the kernel device name has changed */
 925                                 util_strscpy(syspath, sizeof(syspath), udev_device_get_syspath(dev));
 926                                 pos = strrchr(syspath, '/');
 927                                 if (pos != NULL) {
 928                                         pos++;
 929                                         util_strscpy(pos, sizeof(syspath) - (pos - syspath), event->name);
 930                                         udev_device_set_syspath(event->dev, syspath);
 931                                         udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
 932                                         info(event->udev, "changed devpath to '%s'\n", udev_device_get_devpath(dev));
 933                                 }
 934                         }
 935                 }
 936
 937                 if (major(udev_device_get_devnum(dev)) > 0) {
 938                         /* remove/update possible left-over symlinks from old database entry */
 939                         if (event->dev_db != NULL)
 940                                 udev_node_update_old_links(dev, event->dev_db);
 941
 942                         if (!event->mode_set) {
 943                                 if (udev_device_get_devnode_mode(dev) > 0) {
 944                                         /* kernel supplied value */
 945                                         event->mode = udev_device_get_devnode_mode(dev);
 946                                 } else if (event->gid > 0) {
 947                                         /* default 0660 if a group is assigned */
 948                                         event->mode = 0660;
 949                                 } else {
 950                                         /* default 0600 */
 951                                         event->mode = 0600;
 952                                 }
 953                         }
 954
 955                         udev_node_add(dev, event->mode, event->uid, event->gid);
 956                 }
 957
 958                 /* preserve old, or get new initialization timestamp */
 959                 if (event->dev_db != NULL && udev_device_get_usec_initialized(event->dev_db) > 0)
 960                         udev_device_set_usec_initialized(event->dev, udev_device_get_usec_initialized(event->dev_db));
 961                 else if (udev_device_get_usec_initialized(event->dev) == 0)
 962                         udev_device_set_usec_initialized(event->dev, now_usec());
 963
 964                 /* (re)write database file */
 965                 udev_device_update_db(dev);
 966                 udev_device_tag_index(dev, event->dev_db, true);
 967                 udev_device_set_is_initialized(dev);
 968
 969                 udev_device_unref(event->dev_db);
 970                 event->dev_db = NULL;
 971         }
 972 out:
 973         return err;
 974 }
 975
 976 int udev_event_execute_run(struct udev_event *event, const sigset_t *sigmask)
 977 {
 978         struct udev_list_entry *list_entry;
 979         int err = 0;
 980
 981         dbg(event->udev, "executing run list\n");
 982         udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
 983                 const char *cmd = udev_list_entry_get_name(list_entry);
 984
 985                 if (strncmp(cmd, "socket:", strlen("socket:")) == 0) {
 986                         struct udev_monitor *monitor;
 987
 988                         monitor = udev_monitor_new_from_socket(event->udev, &cmd[strlen("socket:")]);
 989                         if (monitor == NULL)
 990                                 continue;
 991                         udev_monitor_send_device(monitor, NULL, event->dev);
 992                         udev_monitor_unref(monitor);
 993                 } else {
 994                         char program[UTIL_PATH_SIZE];
 995                         char **envp;
 996
 997                         if (event->exec_delay > 0) {
 998                                 info(event->udev, "delay execution of '%s'\n", program);
 999                                 sleep(event->exec_delay);
1000                         }
1001
1002                         udev_event_apply_format(event, cmd, program, sizeof(program));
1003                         envp = udev_device_get_properties_envp(event->dev);
1004                         if (udev_event_spawn(event, program, envp, sigmask, NULL, 0) < 0) {
1005                                 if (udev_list_entry_get_num(list_entry))
1006                                         err = -1;
1007                         }
1008                 }
1009         }
1010         return err;
1011 }