2 * Copyright (C) 2003-2013 Kay Sievers <kay@vrfy.org>
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.
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.
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/>.
27 #include <sys/prctl.h>
29 #include <sys/epoll.h>
31 #include <sys/signalfd.h>
34 #include "rtnl-util.h"
36 struct udev_event *udev_event_new(struct udev_device *dev) {
37 struct udev *udev = udev_device_get_udev(dev);
38 struct udev_event *event;
40 event = new0(struct udev_event, 1);
45 udev_list_init(udev, &event->run_list, false);
46 udev_list_init(udev, &event->seclabel_list, false);
47 event->fd_signal = -1;
48 event->birth_usec = now(CLOCK_MONOTONIC);
52 void udev_event_unref(struct udev_event *event) {
55 sd_rtnl_unref(event->rtnl);
56 udev_list_cleanup(&event->run_list);
57 udev_list_cleanup(&event->seclabel_list);
58 free(event->program_result);
63 size_t udev_event_apply_format(struct udev_event *event, const char *src, char *dest, size_t size) {
64 struct udev_device *dev = event->dev;
84 static const struct subst_map {
89 { .name = "devnode", .fmt = 'N', .type = SUBST_DEVNODE },
90 { .name = "tempnode", .fmt = 'N', .type = SUBST_DEVNODE },
91 { .name = "attr", .fmt = 's', .type = SUBST_ATTR },
92 { .name = "sysfs", .fmt = 's', .type = SUBST_ATTR },
93 { .name = "env", .fmt = 'E', .type = SUBST_ENV },
94 { .name = "kernel", .fmt = 'k', .type = SUBST_KERNEL },
95 { .name = "number", .fmt = 'n', .type = SUBST_KERNEL_NUMBER },
96 { .name = "driver", .fmt = 'd', .type = SUBST_DRIVER },
97 { .name = "devpath", .fmt = 'p', .type = SUBST_DEVPATH },
98 { .name = "id", .fmt = 'b', .type = SUBST_ID },
99 { .name = "major", .fmt = 'M', .type = SUBST_MAJOR },
100 { .name = "minor", .fmt = 'm', .type = SUBST_MINOR },
101 { .name = "result", .fmt = 'c', .type = SUBST_RESULT },
102 { .name = "parent", .fmt = 'P', .type = SUBST_PARENT },
103 { .name = "name", .fmt = 'D', .type = SUBST_NAME },
104 { .name = "links", .fmt = 'L', .type = SUBST_LINKS },
105 { .name = "root", .fmt = 'r', .type = SUBST_ROOT },
106 { .name = "sys", .fmt = 'S', .type = SUBST_SYS },
117 enum subst_type type = SUBST_UNKNOWN;
118 char attrbuf[UTIL_PATH_SIZE];
121 while (from[0] != '\0') {
122 if (from[0] == '$') {
123 /* substitute named variable */
126 if (from[1] == '$') {
131 for (i = 0; i < ELEMENTSOF(map); i++) {
132 if (startswith(&from[1], map[i].name)) {
134 from += strlen(map[i].name)+1;
138 } else if (from[0] == '%') {
139 /* substitute format char */
142 if (from[1] == '%') {
147 for (i = 0; i < ELEMENTSOF(map); i++) {
148 if (from[1] == map[i].fmt) {
167 /* extract possible $format{attr} */
168 if (from[0] == '{') {
172 for (i = 0; from[i] != '}'; i++) {
173 if (from[i] == '\0') {
174 log_error("missing closing brace for format '%s'", src);
178 if (i >= sizeof(attrbuf))
180 memcpy(attrbuf, from, i);
190 l = strpcpy(&s, l, udev_device_get_devpath(dev));
193 l = strpcpy(&s, l, udev_device_get_sysname(dev));
195 case SUBST_KERNEL_NUMBER:
196 if (udev_device_get_sysnum(dev) == NULL)
198 l = strpcpy(&s, l, udev_device_get_sysnum(dev));
201 if (event->dev_parent == NULL)
203 l = strpcpy(&s, l, udev_device_get_sysname(event->dev_parent));
208 if (event->dev_parent == NULL)
211 driver = udev_device_get_driver(event->dev_parent);
214 l = strpcpy(&s, l, driver);
218 char num[UTIL_PATH_SIZE];
220 sprintf(num, "%u", major(udev_device_get_devnum(dev)));
221 l = strpcpy(&s, l, num);
225 char num[UTIL_PATH_SIZE];
227 sprintf(num, "%u", minor(udev_device_get_devnum(dev)));
228 l = strpcpy(&s, l, num);
235 if (event->program_result == NULL)
237 /* get part part of the result string */
240 i = strtoul(attr, &rest, 10);
242 char result[UTIL_PATH_SIZE];
243 char tmp[UTIL_PATH_SIZE];
246 strscpy(result, sizeof(result), event->program_result);
249 while (cpos[0] != '\0' && !isspace(cpos[0]))
251 while (isspace(cpos[0]))
257 log_error("requested part of result string not found");
260 strscpy(tmp, sizeof(tmp), cpos);
261 /* %{2+}c copies the whole string from the second part on */
262 if (rest[0] != '+') {
263 cpos = strchr(tmp, ' ');
267 l = strpcpy(&s, l, tmp);
269 l = strpcpy(&s, l, event->program_result);
274 const char *value = NULL;
275 char vbuf[UTIL_NAME_SIZE];
280 log_error("missing file parameter for attr");
284 /* try to read the value specified by "[dmi/id]product_name" */
285 if (util_resolve_subsys_kernel(event->udev, attr, vbuf, sizeof(vbuf), 1) == 0)
288 /* try to read the attribute the device */
290 value = udev_device_get_sysattr_value(event->dev, attr);
292 /* try to read the attribute of the parent device, other matches have selected */
293 if (value == NULL && event->dev_parent != NULL && event->dev_parent != event->dev)
294 value = udev_device_get_sysattr_value(event->dev_parent, attr);
299 /* strip trailing whitespace, and replace unwanted characters */
301 strscpy(vbuf, sizeof(vbuf), value);
303 while (len > 0 && isspace(vbuf[--len]))
305 count = util_replace_chars(vbuf, UDEV_ALLOWED_CHARS_INPUT);
307 log_debug("%i character(s) replaced" , count);
308 l = strpcpy(&s, l, vbuf);
312 struct udev_device *dev_parent;
315 dev_parent = udev_device_get_parent(event->dev);
316 if (dev_parent == NULL)
318 devnode = udev_device_get_devnode(dev_parent);
320 l = strpcpy(&s, l, devnode + strlen("/dev/"));
324 if (udev_device_get_devnode(dev) != NULL)
325 l = strpcpy(&s, l, udev_device_get_devnode(dev));
328 if (event->name != NULL)
329 l = strpcpy(&s, l, event->name);
330 else if (udev_device_get_devnode(dev) != NULL)
331 l = strpcpy(&s, l, udev_device_get_devnode(dev) + strlen("/dev/"));
333 l = strpcpy(&s, l, udev_device_get_sysname(dev));
336 struct udev_list_entry *list_entry;
338 list_entry = udev_device_get_devlinks_list_entry(dev);
339 if (list_entry == NULL)
341 l = strpcpy(&s, l, udev_list_entry_get_name(list_entry) + strlen("/dev/"));
342 udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
343 l = strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry) + strlen("/dev/"), NULL);
347 l = strpcpy(&s, l, "/dev");
350 l = strpcpy(&s, l, "/sys");
358 value = udev_device_get_property_value(event->dev, attr);
361 l = strpcpy(&s, l, value);
365 log_error("unknown substitution type=%i", type);
375 static int spawn_exec(struct udev_event *event,
376 const char *cmd, char *const argv[], char **envp, const sigset_t *sigmask,
377 int fd_stdout, int fd_stderr) {
378 _cleanup_close_ int fd = -1;
380 /* discard child output or connect to pipe */
381 fd = open("/dev/null", O_RDWR);
383 dup2(fd, STDIN_FILENO);
385 dup2(fd, STDOUT_FILENO);
387 dup2(fd, STDERR_FILENO);
389 log_error_errno(errno, "open /dev/null failed: %m");
391 /* connect pipes to std{out,err} */
392 if (fd_stdout >= 0) {
393 dup2(fd_stdout, STDOUT_FILENO);
394 safe_close(fd_stdout);
396 if (fd_stderr >= 0) {
397 dup2(fd_stderr, STDERR_FILENO);
398 safe_close(fd_stderr);
401 /* terminate child in case parent goes away */
402 prctl(PR_SET_PDEATHSIG, SIGTERM);
404 /* restore original udev sigmask before exec */
406 sigprocmask(SIG_SETMASK, sigmask, NULL);
408 execve(argv[0], argv, envp);
411 log_error_errno(errno, "failed to execute '%s' '%s': %m", argv[0], cmd);
416 static void spawn_read(struct udev_event *event,
419 int fd_stdout, int fd_stderr,
420 char *result, size_t ressize) {
421 _cleanup_close_ int fd_ep = -1;
422 struct epoll_event ep_outpipe = {
424 .data.ptr = &fd_stdout,
426 struct epoll_event ep_errpipe = {
428 .data.ptr = &fd_stderr,
433 /* read from child if requested */
434 if (fd_stdout < 0 && fd_stderr < 0)
437 fd_ep = epoll_create1(EPOLL_CLOEXEC);
439 log_error_errno(errno, "error creating epoll fd: %m");
443 if (fd_stdout >= 0) {
444 r = epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe);
446 log_error_errno(errno, "fail to add stdout fd to epoll: %m");
451 if (fd_stderr >= 0) {
452 r = epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe);
454 log_error_errno(errno, "fail to add stderr fd to epoll: %m");
459 /* read child output */
460 while (fd_stdout >= 0 || fd_stderr >= 0) {
463 struct epoll_event ev[4];
466 if (timeout_usec > 0) {
469 age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
470 if (age_usec >= timeout_usec) {
471 log_error("timeout '%s'", cmd);
474 timeout = ((timeout_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
479 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
483 log_error_errno(errno, "failed to poll: %m");
485 } else if (fdcount == 0) {
486 log_error("timeout '%s'", cmd);
490 for (i = 0; i < fdcount; i++) {
491 int *fd = (int *)ev[i].data.ptr;
496 if (ev[i].events & EPOLLIN) {
500 count = read(*fd, buf, sizeof(buf)-1);
505 /* store stdout result */
506 if (result != NULL && *fd == fd_stdout) {
507 if (respos + count < ressize) {
508 memcpy(&result[respos], buf, count);
511 log_error("'%s' ressize %zu too short", cmd, ressize);
515 /* log debug output only if we watch stderr */
516 if (fd_stderr >= 0) {
521 while ((line = strsep(&pos, "\n"))) {
522 if (pos != NULL || line[0] != '\0')
523 log_debug("'%s'(%s) '%s'", cmd, *fd == fd_stdout ? "out" : "err" , line);
526 } else if (ev[i].events & EPOLLHUP) {
527 r = epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL);
529 log_error_errno(errno, "failed to remove fd from epoll: %m");
537 /* return the child's stdout string */
539 result[respos] = '\0';
542 static int spawn_wait(struct udev_event *event,
544 usec_t timeout_warn_usec,
545 const char *cmd, pid_t pid) {
546 struct pollfd pfd[1];
549 pfd[0].events = POLLIN;
550 pfd[0].fd = event->fd_signal;
554 int timeout_warn = 0;
557 if (timeout_usec > 0) {
560 age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
561 if (age_usec >= timeout_usec)
564 if (timeout_warn_usec > 0)
565 timeout_warn = ((timeout_warn_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
567 timeout = ((timeout_usec - timeout_warn_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
573 fdcount = poll(pfd, 1, timeout_warn);
578 log_error_errno(errno, "failed to poll: %m");
582 log_warning("slow: '%s' ["PID_FMT"]", cmd, pid);
584 fdcount = poll(pfd, 1, timeout);
589 log_error_errno(errno, "failed to poll: %m");
593 log_error("timeout: killing '%s' ["PID_FMT"]", cmd, pid);
598 if (pfd[0].revents & POLLIN) {
599 struct signalfd_siginfo fdsi;
603 size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
604 if (size != sizeof(struct signalfd_siginfo))
607 switch (fdsi.ssi_signo) {
609 event->sigterm = true;
612 if (waitpid(pid, &status, WNOHANG) < 0)
614 if (WIFEXITED(status)) {
615 log_debug("'%s' ["PID_FMT"] exit with return code %i", cmd, pid, WEXITSTATUS(status));
616 if (WEXITSTATUS(status) != 0)
618 } else if (WIFSIGNALED(status)) {
619 log_error("'%s' ["PID_FMT"] terminated by signal %i (%s)", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
621 } else if (WIFSTOPPED(status)) {
622 log_error("'%s' ["PID_FMT"] stopped", cmd, pid);
624 } else if (WIFCONTINUED(status)) {
625 log_error("'%s' ["PID_FMT"] continued", cmd, pid);
628 log_error("'%s' ["PID_FMT"] exit with status 0x%04x", cmd, pid, status);
640 int udev_build_argv(struct udev *udev, char *cmd, int *argc, char *argv[]) {
644 if (strchr(cmd, ' ') == NULL) {
650 while (pos != NULL && pos[0] != '\0') {
651 if (pos[0] == '\'') {
652 /* do not separate quotes */
654 argv[i] = strsep(&pos, "\'");
656 while (pos[0] == ' ')
659 argv[i] = strsep(&pos, " ");
661 while (pos[0] == ' ')
673 int udev_event_spawn(struct udev_event *event,
675 usec_t timeout_warn_usec,
676 const char *cmd, char **envp, const sigset_t *sigmask,
677 char *result, size_t ressize) {
678 int outpipe[2] = {-1, -1};
679 int errpipe[2] = {-1, -1};
681 char arg[UTIL_PATH_SIZE];
683 char program[UTIL_PATH_SIZE];
686 strscpy(arg, sizeof(arg), cmd);
687 udev_build_argv(event->udev, arg, NULL, argv);
689 /* pipes from child to parent */
690 if (result != NULL || log_get_max_level() >= LOG_INFO) {
691 if (pipe2(outpipe, O_NONBLOCK) != 0) {
693 log_error_errno(errno, "pipe failed: %m");
697 if (log_get_max_level() >= LOG_INFO) {
698 if (pipe2(errpipe, O_NONBLOCK) != 0) {
700 log_error_errno(errno, "pipe failed: %m");
705 /* allow programs in /usr/lib/udev/ to be called without the path */
706 if (argv[0][0] != '/') {
707 strscpyl(program, sizeof(program), UDEVLIBEXECDIR "/", argv[0], NULL);
714 /* child closes parent's ends of pipes */
715 if (outpipe[READ_END] >= 0) {
716 close(outpipe[READ_END]);
717 outpipe[READ_END] = -1;
719 if (errpipe[READ_END] >= 0) {
720 close(errpipe[READ_END]);
721 errpipe[READ_END] = -1;
724 log_debug("starting '%s'", cmd);
726 spawn_exec(event, cmd, argv, envp, sigmask,
727 outpipe[WRITE_END], errpipe[WRITE_END]);
731 log_error_errno(errno, "fork of '%s' failed: %m", cmd);
735 /* parent closed child's ends of pipes */
736 if (outpipe[WRITE_END] >= 0) {
737 close(outpipe[WRITE_END]);
738 outpipe[WRITE_END] = -1;
740 if (errpipe[WRITE_END] >= 0) {
741 close(errpipe[WRITE_END]);
742 errpipe[WRITE_END] = -1;
748 outpipe[READ_END], errpipe[READ_END],
751 err = spawn_wait(event, timeout_usec, timeout_warn_usec, cmd, pid);
755 if (outpipe[READ_END] >= 0)
756 close(outpipe[READ_END]);
757 if (outpipe[WRITE_END] >= 0)
758 close(outpipe[WRITE_END]);
759 if (errpipe[READ_END] >= 0)
760 close(errpipe[READ_END]);
761 if (errpipe[WRITE_END] >= 0)
762 close(errpipe[WRITE_END]);
766 static int rename_netif(struct udev_event *event) {
767 struct udev_device *dev = event->dev;
772 oldname = udev_device_get_sysname(dev);
774 strscpy(name, IFNAMSIZ, event->name);
776 r = rtnl_set_link_name(&event->rtnl, udev_device_get_ifindex(dev), name);
778 return log_error_errno(r, "Error changing net interface name '%s' to '%s': %m", oldname, name);
780 log_debug("renamed network interface '%s' to '%s'", oldname, name);
785 void udev_event_execute_rules(struct udev_event *event,
786 usec_t timeout_usec, usec_t timeout_warn_usec,
787 struct udev_list *properties_list,
788 struct udev_rules *rules,
789 const sigset_t *sigmask) {
790 struct udev_device *dev = event->dev;
792 if (udev_device_get_subsystem(dev) == NULL)
795 if (streq(udev_device_get_action(dev), "remove")) {
796 if (major(udev_device_get_devnum(dev)) != 0)
797 udev_watch_end(event->udev, dev);
799 udev_rules_apply_to_event(rules, event,
800 timeout_usec, timeout_warn_usec,
804 if (major(udev_device_get_devnum(dev)) != 0)
805 udev_node_remove(dev);
807 udev_device_delete_db(dev);
808 udev_device_tag_index(dev, NULL, false);
810 event->dev_db = udev_device_clone_with_db(dev);
811 if (event->dev_db != NULL) {
812 /* disable watch during event processing */
813 if (major(udev_device_get_devnum(dev)) != 0)
814 udev_watch_end(event->udev, event->dev_db);
817 if (major(udev_device_get_devnum(dev)) == 0 &&
818 streq(udev_device_get_action(dev), "move"))
819 udev_device_copy_properties(dev, event->dev_db);
821 udev_rules_apply_to_event(rules, event,
822 timeout_usec, timeout_warn_usec,
826 /* rename a new network interface, if needed */
827 if (udev_device_get_ifindex(dev) > 0 && streq(udev_device_get_action(dev), "add") &&
828 event->name != NULL && !streq(event->name, udev_device_get_sysname(dev))) {
831 r = rename_netif(event);
833 log_warning_errno(r, "could not rename interface '%d' from '%s' to '%s': %m", udev_device_get_ifindex(dev),
834 udev_device_get_sysname(dev), event->name);
836 r = udev_device_rename(dev, event->name);
838 log_warning_errno(r, "renamed interface '%d' from '%s' to '%s', but could not update udev_device: %m",
839 udev_device_get_ifindex(dev), udev_device_get_sysname(dev), event->name);
841 log_debug("changed devpath to '%s'", udev_device_get_devpath(dev));
845 if (major(udev_device_get_devnum(dev)) > 0) {
848 /* remove/update possible left-over symlinks from old database entry */
849 if (event->dev_db != NULL)
850 udev_node_update_old_links(dev, event->dev_db);
852 if (!event->owner_set)
853 event->uid = udev_device_get_devnode_uid(dev);
855 if (!event->group_set)
856 event->gid = udev_device_get_devnode_gid(dev);
858 if (!event->mode_set) {
859 if (udev_device_get_devnode_mode(dev) > 0) {
860 /* kernel supplied value */
861 event->mode = udev_device_get_devnode_mode(dev);
862 } else if (event->gid > 0) {
863 /* default 0660 if a group is assigned */
871 apply = streq(udev_device_get_action(dev), "add") || event->owner_set || event->group_set || event->mode_set;
872 udev_node_add(dev, apply, event->mode, event->uid, event->gid, &event->seclabel_list);
875 /* preserve old, or get new initialization timestamp */
876 udev_device_ensure_usec_initialized(event->dev, event->dev_db);
878 /* (re)write database file */
879 udev_device_update_db(dev);
880 udev_device_tag_index(dev, event->dev_db, true);
881 udev_device_set_is_initialized(dev);
883 udev_device_unref(event->dev_db);
884 event->dev_db = NULL;
888 void udev_event_execute_run(struct udev_event *event, usec_t timeout_usec, usec_t timeout_warn_usec, const sigset_t *sigmask) {
889 struct udev_list_entry *list_entry;
891 udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
892 const char *cmd = udev_list_entry_get_name(list_entry);
893 enum udev_builtin_cmd builtin_cmd = udev_list_entry_get_num(list_entry);
895 if (builtin_cmd < UDEV_BUILTIN_MAX) {
896 char command[UTIL_PATH_SIZE];
898 udev_event_apply_format(event, cmd, command, sizeof(command));
899 udev_builtin_run(event->dev, builtin_cmd, command, false);
901 char program[UTIL_PATH_SIZE];
904 if (event->exec_delay > 0) {
905 log_debug("delay execution of '%s'", program);
906 sleep(event->exec_delay);
909 udev_event_apply_format(event, cmd, program, sizeof(program));
910 envp = udev_device_get_properties_envp(event->dev);
911 udev_event_spawn(event, timeout_usec, timeout_warn_usec, program, envp, sigmask, NULL, 0);