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/>.
28 #include <sys/prctl.h>
30 #include <sys/epoll.h>
32 #include <sys/signalfd.h>
35 #include "rtnl-util.h"
37 struct udev_event *udev_event_new(struct udev_device *dev) {
38 struct udev *udev = udev_device_get_udev(dev);
39 struct udev_event *event;
41 event = new0(struct udev_event, 1);
46 udev_list_init(udev, &event->run_list, false);
47 udev_list_init(udev, &event->seclabel_list, false);
48 event->fd_signal = -1;
49 event->birth_usec = now(CLOCK_MONOTONIC);
53 void udev_event_unref(struct udev_event *event) {
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, "%d", major(udev_device_get_devnum(dev)));
221 l = strpcpy(&s, l, num);
225 char num[UTIL_PATH_SIZE];
227 sprintf(num, "%d", 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) {
381 /* discard child output or connect to pipe */
382 fd = open("/dev/null", O_RDWR);
384 dup2(fd, STDIN_FILENO);
386 dup2(fd, STDOUT_FILENO);
388 dup2(fd, STDERR_FILENO);
391 log_error("open /dev/null failed: %m");
394 /* connect pipes to std{out,err} */
395 if (fd_stdout >= 0) {
396 dup2(fd_stdout, STDOUT_FILENO);
399 if (fd_stderr >= 0) {
400 dup2(fd_stderr, STDERR_FILENO);
404 /* terminate child in case parent goes away */
405 prctl(PR_SET_PDEATHSIG, SIGTERM);
407 /* restore original udev sigmask before exec */
409 sigprocmask(SIG_SETMASK, sigmask, NULL);
411 execve(argv[0], argv, envp);
415 log_error("failed to execute '%s' '%s': %m", argv[0], cmd);
419 static void spawn_read(struct udev_event *event,
422 int fd_stdout, int fd_stderr,
423 char *result, size_t ressize) {
426 struct epoll_event ep_outpipe, ep_errpipe;
428 /* read from child if requested */
429 if (fd_stdout < 0 && fd_stderr < 0)
432 fd_ep = epoll_create1(EPOLL_CLOEXEC);
434 log_error("error creating epoll fd: %m");
438 if (fd_stdout >= 0) {
439 memzero(&ep_outpipe, sizeof(struct epoll_event));
440 ep_outpipe.events = EPOLLIN;
441 ep_outpipe.data.ptr = &fd_stdout;
442 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe) < 0) {
443 log_error("fail to add fd to epoll: %m");
448 if (fd_stderr >= 0) {
449 memzero(&ep_errpipe, sizeof(struct epoll_event));
450 ep_errpipe.events = EPOLLIN;
451 ep_errpipe.data.ptr = &fd_stderr;
452 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe) < 0) {
453 log_error("fail to add fd to epoll: %m");
458 /* read child output */
459 while (fd_stdout >= 0 || fd_stderr >= 0) {
462 struct epoll_event ev[4];
465 if (timeout_usec > 0) {
468 age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
469 if (age_usec >= timeout_usec) {
470 log_error("timeout '%s'", cmd);
473 timeout = ((timeout_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
478 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
482 log_error("failed to poll: %m");
486 log_error("timeout '%s'", cmd);
490 for (i = 0; i < fdcount; i++) {
491 int *fd = (int *)ev[i].data.ptr;
493 if (ev[i].events & EPOLLIN) {
497 count = read(*fd, buf, sizeof(buf)-1);
502 /* store stdout result */
503 if (result != NULL && *fd == fd_stdout) {
504 if (respos + count < ressize) {
505 memcpy(&result[respos], buf, count);
508 log_error("'%s' ressize %zd too short", cmd, ressize);
512 /* log debug output only if we watch stderr */
513 if (fd_stderr >= 0) {
518 while ((line = strsep(&pos, "\n"))) {
519 if (pos != NULL || line[0] != '\0')
520 log_debug("'%s'(%s) '%s'", cmd, *fd == fd_stdout ? "out" : "err" , line);
523 } else if (ev[i].events & EPOLLHUP) {
524 if (epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL) < 0) {
525 log_error("failed to remove fd from epoll: %m");
533 /* return the child's stdout string */
535 result[respos] = '\0';
541 static int spawn_wait(struct udev_event *event,
543 const char *cmd, pid_t pid) {
544 struct pollfd pfd[1];
547 pfd[0].events = POLLIN;
548 pfd[0].fd = event->fd_signal;
554 if (timeout_usec > 0) {
557 age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
558 if (age_usec >= timeout_usec)
561 timeout = ((timeout_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
566 fdcount = poll(pfd, 1, timeout);
571 log_error("failed to poll: %m");
575 log_error("timeout: killing '%s' [%u]", cmd, pid);
579 if (pfd[0].revents & POLLIN) {
580 struct signalfd_siginfo fdsi;
584 size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
585 if (size != sizeof(struct signalfd_siginfo))
588 switch (fdsi.ssi_signo) {
590 event->sigterm = true;
593 if (waitpid(pid, &status, WNOHANG) < 0)
595 if (WIFEXITED(status)) {
596 log_debug("'%s' [%u] exit with return code %i", cmd, pid, WEXITSTATUS(status));
597 if (WEXITSTATUS(status) != 0)
599 } else if (WIFSIGNALED(status)) {
600 log_error("'%s' [%u] terminated by signal %i (%s)", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
602 } else if (WIFSTOPPED(status)) {
603 log_error("'%s' [%u] stopped", cmd, pid);
605 } else if (WIFCONTINUED(status)) {
606 log_error("'%s' [%u] continued", cmd, pid);
609 log_error("'%s' [%u] exit with status 0x%04x", cmd, pid, status);
621 int udev_build_argv(struct udev *udev, char *cmd, int *argc, char *argv[]) {
625 if (strchr(cmd, ' ') == NULL) {
631 while (pos != NULL && pos[0] != '\0') {
632 if (pos[0] == '\'') {
633 /* do not separate quotes */
635 argv[i] = strsep(&pos, "\'");
637 while (pos[0] == ' ')
640 argv[i] = strsep(&pos, " ");
642 while (pos[0] == ' ')
654 int udev_event_spawn(struct udev_event *event,
656 const char *cmd, char **envp, const sigset_t *sigmask,
657 char *result, size_t ressize) {
658 struct udev *udev = event->udev;
659 int outpipe[2] = {-1, -1};
660 int errpipe[2] = {-1, -1};
662 char arg[UTIL_PATH_SIZE];
664 char program[UTIL_PATH_SIZE];
667 strscpy(arg, sizeof(arg), cmd);
668 udev_build_argv(event->udev, arg, NULL, argv);
670 /* pipes from child to parent */
671 if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
672 if (pipe2(outpipe, O_NONBLOCK) != 0) {
674 log_error("pipe failed: %m");
678 if (udev_get_log_priority(udev) >= LOG_INFO) {
679 if (pipe2(errpipe, O_NONBLOCK) != 0) {
681 log_error("pipe failed: %m");
686 /* allow programs in /usr/lib/udev/ to be called without the path */
687 if (argv[0][0] != '/') {
688 strscpyl(program, sizeof(program), UDEVLIBEXECDIR "/", argv[0], NULL);
695 /* child closes parent's ends of pipes */
696 if (outpipe[READ_END] >= 0) {
697 close(outpipe[READ_END]);
698 outpipe[READ_END] = -1;
700 if (errpipe[READ_END] >= 0) {
701 close(errpipe[READ_END]);
702 errpipe[READ_END] = -1;
705 log_debug("starting '%s'", cmd);
707 spawn_exec(event, cmd, argv, envp, sigmask,
708 outpipe[WRITE_END], errpipe[WRITE_END]);
712 log_error("fork of '%s' failed: %m", cmd);
716 /* parent closed child's ends of pipes */
717 if (outpipe[WRITE_END] >= 0) {
718 close(outpipe[WRITE_END]);
719 outpipe[WRITE_END] = -1;
721 if (errpipe[WRITE_END] >= 0) {
722 close(errpipe[WRITE_END]);
723 errpipe[WRITE_END] = -1;
729 outpipe[READ_END], errpipe[READ_END],
732 err = spawn_wait(event, timeout_usec, cmd, pid);
736 if (outpipe[READ_END] >= 0)
737 close(outpipe[READ_END]);
738 if (outpipe[WRITE_END] >= 0)
739 close(outpipe[WRITE_END]);
740 if (errpipe[READ_END] >= 0)
741 close(errpipe[READ_END]);
742 if (errpipe[WRITE_END] >= 0)
743 close(errpipe[WRITE_END]);
747 static int rename_netif(struct udev_event *event) {
748 struct udev_device *dev = event->dev;
749 _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
754 oldname = udev_device_get_sysname(dev);
756 log_debug("changing net interface name from '%s' to '%s'",
757 oldname, event->name);
759 strscpy(name, IFNAMSIZ, event->name);
761 r = sd_rtnl_open(&rtnl, 0);
765 r = rtnl_set_link_name(rtnl, udev_device_get_ifindex(dev), name);
767 log_error("error changing net interface name %s to %s: %s",
768 oldname, name, strerror(-r));
770 print_kmsg("renamed network interface %s to %s\n", oldname, name);
775 void udev_event_execute_rules(struct udev_event *event,
777 struct udev_rules *rules, const sigset_t *sigmask) {
778 struct udev_device *dev = event->dev;
780 if (udev_device_get_subsystem(dev) == NULL)
783 if (streq(udev_device_get_action(dev), "remove")) {
784 udev_device_read_db(dev, NULL);
785 udev_device_delete_db(dev);
786 udev_device_tag_index(dev, NULL, false);
788 if (major(udev_device_get_devnum(dev)) != 0)
789 udev_watch_end(event->udev, dev);
791 udev_rules_apply_to_event(rules, event, timeout_usec, sigmask);
793 if (major(udev_device_get_devnum(dev)) != 0)
794 udev_node_remove(dev);
796 event->dev_db = udev_device_new(event->udev);
797 if (event->dev_db != NULL) {
798 udev_device_set_syspath(event->dev_db, udev_device_get_syspath(dev));
799 udev_device_set_subsystem(event->dev_db, udev_device_get_subsystem(dev));
800 udev_device_read_db(event->dev_db, NULL);
801 udev_device_set_info_loaded(event->dev_db);
803 /* disable watch during event processing */
804 if (major(udev_device_get_devnum(dev)) != 0)
805 udev_watch_end(event->udev, event->dev_db);
808 udev_rules_apply_to_event(rules, event, timeout_usec, sigmask);
810 /* rename a new network interface, if needed */
811 if (udev_device_get_ifindex(dev) > 0 && streq(udev_device_get_action(dev), "add") &&
812 event->name != NULL && !streq(event->name, udev_device_get_sysname(dev))) {
813 char syspath[UTIL_PATH_SIZE];
817 r = rename_netif(event);
819 log_debug("renamed netif to '%s'", event->name);
821 /* remember old name */
822 udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
824 /* now change the devpath, because the kernel device name has changed */
825 strscpy(syspath, sizeof(syspath), udev_device_get_syspath(dev));
826 pos = strrchr(syspath, '/');
829 strscpy(pos, sizeof(syspath) - (pos - syspath), event->name);
830 udev_device_set_syspath(event->dev, syspath);
831 udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
832 log_debug("changed devpath to '%s'", udev_device_get_devpath(dev));
837 if (major(udev_device_get_devnum(dev)) > 0) {
840 /* remove/update possible left-over symlinks from old database entry */
841 if (event->dev_db != NULL)
842 udev_node_update_old_links(dev, event->dev_db);
844 if (!event->owner_set)
845 event->uid = udev_device_get_devnode_uid(dev);
847 if (!event->group_set)
848 event->gid = udev_device_get_devnode_gid(dev);
850 if (!event->mode_set) {
851 if (udev_device_get_devnode_mode(dev) > 0) {
852 /* kernel supplied value */
853 event->mode = udev_device_get_devnode_mode(dev);
854 } else if (event->gid > 0) {
855 /* default 0660 if a group is assigned */
863 apply = streq(udev_device_get_action(dev), "add") || event->owner_set || event->group_set || event->mode_set;
864 udev_node_add(dev, apply, event->mode, event->uid, event->gid, &event->seclabel_list);
867 /* preserve old, or get new initialization timestamp */
868 if (event->dev_db != NULL && udev_device_get_usec_initialized(event->dev_db) > 0)
869 udev_device_set_usec_initialized(event->dev, udev_device_get_usec_initialized(event->dev_db));
870 else if (udev_device_get_usec_initialized(event->dev) == 0)
871 udev_device_set_usec_initialized(event->dev, now(CLOCK_MONOTONIC));
873 /* (re)write database file */
874 udev_device_update_db(dev);
875 udev_device_tag_index(dev, event->dev_db, true);
876 udev_device_set_is_initialized(dev);
878 udev_device_unref(event->dev_db);
879 event->dev_db = NULL;
883 void udev_event_execute_run(struct udev_event *event, usec_t timeout_usec, const sigset_t *sigmask) {
884 struct udev_list_entry *list_entry;
886 udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
887 const char *cmd = udev_list_entry_get_name(list_entry);
888 enum udev_builtin_cmd builtin_cmd = udev_list_entry_get_num(list_entry);
890 if (builtin_cmd < UDEV_BUILTIN_MAX) {
891 char command[UTIL_PATH_SIZE];
893 udev_event_apply_format(event, cmd, command, sizeof(command));
894 udev_builtin_run(event->dev, builtin_cmd, command, false);
896 char program[UTIL_PATH_SIZE];
899 if (event->exec_delay > 0) {
900 log_debug("delay execution of '%s'", program);
901 sleep(event->exec_delay);
904 udev_event_apply_format(event, cmd, program, sizeof(program));
905 envp = udev_device_get_properties_envp(event->dev);
906 udev_event_spawn(event, timeout_usec, program, envp, sigmask, NULL, 0);