2 * udevd.c - event listener and serializer
4 * Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
5 * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation version 2 of the License.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 675 Mass Ave, Cambridge, MA 02139, USA.
35 #include <sys/select.h>
37 #include <sys/types.h>
38 #include <sys/socket.h>
41 #include <sys/ioctl.h>
42 #include <linux/types.h>
43 #include <linux/netlink.h>
46 #include "udev_rules.h"
48 #include "udev_selinux.h"
50 static struct udev_rules rules;
51 static int udevd_sock = -1;
52 static int uevent_netlink_sock = -1;
53 static int inotify_fd = -1;
56 static int signal_pipe[2] = {-1, -1};
57 static volatile int sigchilds_waiting;
58 static volatile int udev_exit;
59 static volatile int reload_config;
60 static int run_exec_q;
61 static int stop_exec_q;
62 static int max_childs;
63 static int max_childs_running;
64 static char udev_log[32];
66 static LIST_HEAD(exec_list);
67 static LIST_HEAD(running_list);
71 void log_message(int priority, const char *format, ...)
75 if (priority > udev_log_priority)
78 va_start(args, format);
79 vsyslog(priority, format, args);
84 static void asmlinkage udev_event_sig_handler(int signum)
86 if (signum == SIGALRM)
90 static int udev_event_process(struct udevd_uevent_msg *msg)
97 /* set signal handlers */
98 memset(&act, 0x00, sizeof(act));
99 act.sa_handler = (void (*)(int)) udev_event_sig_handler;
100 sigemptyset (&act.sa_mask);
102 sigaction(SIGALRM, &act, NULL);
104 /* reset to default */
105 act.sa_handler = SIG_DFL;
106 sigaction(SIGINT, &act, NULL);
107 sigaction(SIGTERM, &act, NULL);
108 sigaction(SIGCHLD, &act, NULL);
109 sigaction(SIGHUP, &act, NULL);
111 /* trigger timeout to prevent hanging processes */
112 alarm(UDEV_ALARM_TIMEOUT);
114 /* reconstruct event environment from message */
115 for (i = 0; msg->envp[i]; i++)
116 putenv(msg->envp[i]);
118 udev = udev_device_init();
121 strlcpy(udev->action, msg->action, sizeof(udev->action));
122 sysfs_device_set_values(udev->dev, msg->devpath, msg->subsystem, msg->driver);
123 udev->devt = msg->devt;
125 retval = udev_device_event(&rules, udev);
127 /* run programs collected by RUN-key*/
128 if (retval == 0 && !udev->ignore_device && udev_run) {
129 struct name_entry *name_loop;
131 dbg("executing run list");
132 list_for_each_entry(name_loop, &udev->run_list, node) {
133 if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
134 pass_env_to_socket(&name_loop->name[strlen("socket:")], udev->dev->devpath, udev->action);
136 char program[PATH_SIZE];
138 strlcpy(program, name_loop->name, sizeof(program));
139 udev_rules_apply_format(udev, program, sizeof(program));
140 if (run_program(program, udev->dev->subsystem, NULL, 0, NULL,
141 (udev_log_priority >= LOG_INFO)))
147 udev_device_cleanup(udev);
157 static void export_event_state(struct udevd_uevent_msg *msg, enum event_state state)
159 char filename[PATH_SIZE];
160 char filename_failed[PATH_SIZE];
161 char target[PATH_SIZE];
162 size_t start, end, i;
163 struct udevd_uevent_msg *loop_msg;
165 /* add location of queue files */
166 strlcpy(filename, udev_root, sizeof(filename));
167 strlcat(filename, "/", sizeof(filename));
168 start = strlcat(filename, EVENT_QUEUE_DIR, sizeof(filename));
169 end = strlcat(filename, msg->devpath, sizeof(filename));
170 if (end > sizeof(filename))
171 end = sizeof(filename);
173 /* replace '/' to transform path into a filename */
174 for (i = start+1; i < end; i++)
175 if (filename[i] == '/')
176 filename[i] = PATH_TO_NAME_CHAR;
178 /* add location of failed files */
179 strlcpy(filename_failed, udev_root, sizeof(filename_failed));
180 strlcat(filename_failed, "/", sizeof(filename_failed));
181 start = strlcat(filename_failed, EVENT_FAILED_DIR, sizeof(filename_failed));
182 end = strlcat(filename_failed, msg->devpath, sizeof(filename_failed));
183 if (end > sizeof(filename_failed))
184 end = sizeof(filename_failed);
186 /* replace '/' to transform path into a filename */
187 for (i = start+1; i < end; i++)
188 if (filename_failed[i] == '/')
189 filename_failed[i] = PATH_TO_NAME_CHAR;
193 unlink(filename_failed);
194 delete_path(filename_failed);
196 strlcpy(target, sysfs_path, sizeof(target));
197 strlcat(target, msg->devpath, sizeof(target));
198 create_path(filename);
199 symlink(target, filename);
203 unlink(filename_failed);
204 delete_path(filename_failed);
206 /* don't remove, if events for the same path are still pending */
207 list_for_each_entry(loop_msg, &running_list, node)
208 if (loop_msg->devpath && strcmp(loop_msg->devpath, msg->devpath) == 0)
211 list_for_each_entry(loop_msg, &exec_list, node)
212 if (loop_msg->devpath && strcmp(loop_msg->devpath, msg->devpath) == 0)
215 /* move failed events to the failed directory */
216 if (state == EVENT_FAILED) {
217 create_path(filename_failed);
218 rename(filename, filename_failed);
223 /* clean up the queue directory */
224 delete_path(filename);
230 static void msg_queue_delete(struct udevd_uevent_msg *msg)
232 list_del(&msg->node);
234 /* mark as failed, if add event returns non-zero */
235 if (msg->exitstatus && strcmp(msg->action, "add") == 0)
236 export_event_state(msg, EVENT_FAILED);
238 export_event_state(msg, EVENT_FINISHED);
243 static void udev_event_run(struct udevd_uevent_msg *msg)
252 close(uevent_netlink_sock);
256 close(signal_pipe[READ_END]);
257 close(signal_pipe[WRITE_END]);
260 logging_init("udevd-event");
261 setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
263 retval = udev_event_process(msg);
264 info("seq %llu finished", msg->seqnum);
271 err("fork of child failed: %s", strerror(errno));
272 msg_queue_delete(msg);
275 /* get SIGCHLD in main loop */
276 info("seq %llu forked, pid [%d], '%s' '%s', %ld seconds old",
277 msg->seqnum, pid, msg->action, msg->subsystem, time(NULL) - msg->queue_time);
282 static void msg_queue_insert(struct udevd_uevent_msg *msg)
284 char filename[PATH_SIZE];
287 msg->queue_time = time(NULL);
289 strlcpy(filename, udev_root, sizeof(filename));
290 strlcat(filename, "/" EVENT_SEQNUM, sizeof(filename));
291 fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
296 len = sprintf(str, "%llu\n", msg->seqnum);
301 export_event_state(msg, EVENT_QUEUED);
303 /* run all events with a timeout set immediately */
304 if (msg->timeout != 0) {
305 list_add_tail(&msg->node, &running_list);
310 list_add_tail(&msg->node, &exec_list);
314 static int mem_size_mb(void)
322 f = open("/proc/meminfo", O_RDONLY);
326 len = read(f, buf, sizeof(buf)-1);
333 pos = strstr(buf, "MemTotal: ");
337 if (sscanf(pos, "MemTotal: %ld kB", &memsize) != 1)
340 return memsize / 1024;
343 static int cpu_count(void)
351 f = open("/proc/stat", O_RDONLY);
355 len = read(f, buf, sizeof(buf)-1);
361 pos = strstr(buf, "cpu");
365 while (pos != NULL) {
366 if (strncmp(pos, "cpu", 3) == 0 &&isdigit(pos[3]))
368 pos = strstr(&pos[3], "cpu");
376 static int running_processes(void)
384 f = open("/proc/stat", O_RDONLY);
388 len = read(f, buf, sizeof(buf)-1);
394 pos = strstr(buf, "procs_running ");
398 if (sscanf(pos, "procs_running %u", &running) != 1)
404 /* return the number of process es in our session, count only until limit */
405 static int running_processes_in_session(pid_t session, int limit)
411 dir = opendir("/proc");
415 /* read process info from /proc */
416 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
422 pid_t ppid, pgrp, sess;
425 if (!isdigit(dent->d_name[0]))
428 snprintf(procdir, sizeof(procdir), "/proc/%s/stat", dent->d_name);
429 procdir[sizeof(procdir)-1] = '\0';
431 f = open(procdir, O_RDONLY);
435 len = read(f, line, sizeof(line)-1);
443 /* skip ugly program name */
444 pos = strrchr(line, ')') + 2;
448 if (sscanf(pos, "%c %d %d %d ", &state, &ppid, &pgrp, &sess) != 4)
451 /* count only processes in our session */
455 /* count only running, no sleeping processes */
460 if (limit > 0 && running >= limit)
468 static int compare_devpath(const char *running, const char *waiting)
472 for (i = 0; i < PATH_SIZE; i++) {
473 /* identical device event found */
474 if (running[i] == '\0' && waiting[i] == '\0')
477 /* parent device event found */
478 if (running[i] == '\0' && waiting[i] == '/')
481 /* child device event found */
482 if (running[i] == '/' && waiting[i] == '\0')
485 /* no matching event */
486 if (running[i] != waiting[i])
493 /* returns still running task for the same device, its parent or its physical device */
494 static int running_with_devpath(struct udevd_uevent_msg *msg, int limit)
496 struct udevd_uevent_msg *loop_msg;
497 int childs_count = 0;
499 list_for_each_entry(loop_msg, &running_list, node) {
500 if (limit && childs_count++ > limit) {
501 dbg("%llu, maximum number (%i) of child reached", msg->seqnum, childs_count);
505 /* return running parent/child device event */
506 if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
507 dbg("%llu, child device event still running %llu (%s)",
508 msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
512 /* return running physical device event */
513 if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
514 if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
515 dbg("%llu, physical device event still running %llu (%s)",
516 msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
524 /* exec queue management routine executes the events and serializes events in the same sequence */
525 static void msg_queue_manager(void)
527 struct udevd_uevent_msg *loop_msg;
528 struct udevd_uevent_msg *tmp_msg;
531 if (list_empty(&exec_list))
534 running = running_processes();
535 dbg("%d processes runnning on system", running);
537 running = max_childs_running;
539 list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) {
540 /* check running processes in our session and possibly throttle */
541 if (running >= max_childs_running) {
542 running = running_processes_in_session(sid, max_childs_running+10);
543 dbg("at least %d processes running in session", running);
544 if (running >= max_childs_running) {
545 dbg("delay seq %llu, too many processes already running", loop_msg->seqnum);
550 /* don't run two processes for the same devpath and wait for the parent*/
551 if (running_with_devpath(loop_msg, max_childs)) {
552 dbg("delay seq %llu (%s)", loop_msg->seqnum, loop_msg->devpath);
556 /* move event to run list */
557 list_move_tail(&loop_msg->node, &running_list);
558 udev_event_run(loop_msg);
560 dbg("moved seq %llu to running list", loop_msg->seqnum);
564 static struct udevd_uevent_msg *get_msg_from_envbuf(const char *buf, int buf_size)
568 struct udevd_uevent_msg *msg;
572 msg = malloc(sizeof(struct udevd_uevent_msg) + buf_size);
575 memset(msg, 0x00, sizeof(struct udevd_uevent_msg) + buf_size);
577 /* copy environment buffer and reconstruct envp */
578 memcpy(msg->envbuf, buf, buf_size);
580 for (i = 0; (bufpos < buf_size) && (i < UEVENT_NUM_ENVP-2); i++) {
584 key = &msg->envbuf[bufpos];
585 keylen = strlen(key);
587 bufpos += keylen + 1;
588 dbg("add '%s' to msg.envp[%i]", msg->envp[i], i);
590 /* remember some keys for further processing */
591 if (strncmp(key, "ACTION=", 7) == 0)
592 msg->action = &key[7];
593 else if (strncmp(key, "DEVPATH=", 8) == 0)
594 msg->devpath = &key[8];
595 else if (strncmp(key, "SUBSYSTEM=", 10) == 0)
596 msg->subsystem = &key[10];
597 else if (strncmp(key, "DRIVER=", 7) == 0)
598 msg->driver = &key[7];
599 else if (strncmp(key, "SEQNUM=", 7) == 0)
600 msg->seqnum = strtoull(&key[7], NULL, 10);
601 else if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
602 msg->physdevpath = &key[12];
603 else if (strncmp(key, "MAJOR=", 6) == 0)
604 major = strtoull(&key[6], NULL, 10);
605 else if (strncmp(key, "MINOR=", 6) == 0)
606 minor = strtoull(&key[6], NULL, 10);
607 else if (strncmp(key, "TIMEOUT=", 8) == 0)
608 msg->timeout = strtoull(&key[8], NULL, 10);
610 msg->devt = makedev(major, minor);
611 msg->envp[i++] = "UDEVD_EVENT=1";
614 if (msg->devpath == NULL || msg->action == NULL) {
615 info("DEVPATH or ACTION missing, ignore message");
622 /* receive the udevd message from userspace */
623 static void get_ctrl_msg(void)
625 struct udevd_ctrl_msg ctrl_msg;
628 struct cmsghdr *cmsg;
631 char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
634 memset(&ctrl_msg, 0x00, sizeof(struct udevd_ctrl_msg));
635 iov.iov_base = &ctrl_msg;
636 iov.iov_len = sizeof(struct udevd_ctrl_msg);
638 memset(&smsg, 0x00, sizeof(struct msghdr));
641 smsg.msg_control = cred_msg;
642 smsg.msg_controllen = sizeof(cred_msg);
644 size = recvmsg(udevd_sock, &smsg, 0);
647 err("unable to receive user udevd message: %s", strerror(errno));
650 cmsg = CMSG_FIRSTHDR(&smsg);
651 cred = (struct ucred *) CMSG_DATA(cmsg);
653 if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
654 err("no sender credentials received, message ignored");
658 if (cred->uid != 0) {
659 err("sender uid=%i, message ignored", cred->uid);
663 if (strncmp(ctrl_msg.magic, UDEVD_CTRL_MAGIC, sizeof(UDEVD_CTRL_MAGIC)) != 0 ) {
664 err("message magic '%s' doesn't match, ignore it", ctrl_msg.magic);
668 switch (ctrl_msg.type) {
669 case UDEVD_CTRL_STOP_EXEC_QUEUE:
670 info("udevd message (STOP_EXEC_QUEUE) received");
673 case UDEVD_CTRL_START_EXEC_QUEUE:
674 info("udevd message (START_EXEC_QUEUE) received");
678 case UDEVD_CTRL_SET_LOG_LEVEL:
679 intval = (int *) ctrl_msg.buf;
680 info("udevd message (SET_LOG_PRIORITY) received, udev_log_priority=%i", *intval);
681 udev_log_priority = *intval;
682 sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
685 case UDEVD_CTRL_SET_MAX_CHILDS:
686 intval = (int *) ctrl_msg.buf;
687 info("udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i", *intval);
688 max_childs = *intval;
690 case UDEVD_CTRL_SET_MAX_CHILDS_RUNNING:
691 intval = (int *) ctrl_msg.buf;
692 info("udevd message (UDEVD_SET_MAX_CHILDS_RUNNING) received, max_childs=%i", *intval);
693 max_childs_running = *intval;
695 case UDEVD_CTRL_RELOAD_RULES:
696 info("udevd message (RELOAD_RULES) received");
700 err("unknown control message type");
704 /* receive the kernel user event message and do some sanity checks */
705 static struct udevd_uevent_msg *get_netlink_msg(void)
707 struct udevd_uevent_msg *msg;
710 static char buffer[UEVENT_BUFFER_SIZE+512];
713 size = recv(uevent_netlink_sock, &buffer, sizeof(buffer), 0);
716 err("unable to receive kernel netlink message: %s", strerror(errno));
720 if ((size_t)size > sizeof(buffer)-1)
721 size = sizeof(buffer)-1;
723 dbg("uevent_size=%zi", size);
725 /* start of event payload */
726 bufpos = strlen(buffer)+1;
727 msg = get_msg_from_envbuf(&buffer[bufpos], size-bufpos);
731 /* validate message */
732 pos = strchr(buffer, '@');
734 err("invalid uevent '%s'", buffer);
740 if (msg->action == NULL) {
741 info("no ACTION in payload found, skip event '%s'", buffer);
746 if (strcmp(msg->action, buffer) != 0) {
747 err("ACTION in payload does not match uevent, skip event '%s'", buffer);
755 static void asmlinkage sig_handler(int signum)
763 /* set flag, then write to pipe if needed */
764 sigchilds_waiting = 1;
771 /* write to pipe, which will wakeup select() in our mainloop */
772 write(signal_pipe[WRITE_END], "", 1);
775 static void udev_done(int pid, int exitstatus)
777 /* find msg associated with pid and delete it */
778 struct udevd_uevent_msg *msg;
780 list_for_each_entry(msg, &running_list, node) {
781 if (msg->pid == pid) {
782 info("seq %llu, pid [%d] exit with %i, %ld seconds old", msg->seqnum, msg->pid,
783 exitstatus, time(NULL) - msg->queue_time);
784 msg->exitstatus = exitstatus;
785 msg_queue_delete(msg);
787 /* there may be events waiting with the same devpath */
794 static void reap_sigchilds(void)
800 pid = waitpid(-1, &status, WNOHANG);
803 if (WIFEXITED(status))
804 status = WEXITSTATUS(status);
805 else if (WIFSIGNALED(status))
806 status = WTERMSIG(status) + 128;
809 udev_done(pid, status);
813 static int init_udevd_socket(void)
815 struct sockaddr_un saddr;
817 const int feature_on = 1;
820 memset(&saddr, 0x00, sizeof(saddr));
821 saddr.sun_family = AF_LOCAL;
822 /* use abstract namespace for socket path */
823 strcpy(&saddr.sun_path[1], UDEVD_CTRL_SOCK_PATH);
824 addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
826 udevd_sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
827 if (udevd_sock == -1) {
828 err("error getting socket: %s", strerror(errno));
832 /* the bind takes care of ensuring only one copy running */
833 retval = bind(udevd_sock, (struct sockaddr *) &saddr, addrlen);
835 err("bind failed: %s", strerror(errno));
841 /* enable receiving of the sender credentials */
842 setsockopt(udevd_sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
847 static int init_uevent_netlink_sock(void)
849 struct sockaddr_nl snl;
850 const int buffersize = 16 * 1024 * 1024;
853 memset(&snl, 0x00, sizeof(struct sockaddr_nl));
854 snl.nl_family = AF_NETLINK;
855 snl.nl_pid = getpid();
858 uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
859 if (uevent_netlink_sock == -1) {
860 err("error getting socket: %s", strerror(errno));
864 /* set receive buffersize */
865 setsockopt(uevent_netlink_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
867 retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl, sizeof(struct sockaddr_nl));
869 err("bind failed: %s", strerror(errno));
870 close(uevent_netlink_sock);
871 uevent_netlink_sock = -1;
877 static void export_initial_seqnum(void)
879 char filename[PATH_SIZE];
884 strlcpy(filename, sysfs_path, sizeof(filename));
885 strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
886 fd = open(filename, O_RDONLY);
888 len = read(fd, seqnum, sizeof(seqnum)-1);
892 strcpy(seqnum, "0\n");
895 strlcpy(filename, udev_root, sizeof(filename));
896 strlcat(filename, "/" EVENT_SEQNUM, sizeof(filename));
897 create_path(filename);
898 fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
900 write(fd, seqnum, len);
905 int main(int argc, char *argv[], char *envp[])
909 struct sigaction act;
917 /* redirect std fd's, if the kernel forks us, we don't have them at all */
918 fd = open("/dev/null", O_RDWR);
920 if (fd != STDIN_FILENO)
921 dup2(fd, STDIN_FILENO);
922 if (fd != STDOUT_FILENO)
923 dup2(fd, STDOUT_FILENO);
924 if (fd != STDERR_FILENO)
925 dup2(fd, STDERR_FILENO);
926 if (fd > STDERR_FILENO)
930 logging_init("udevd");
932 err("fatal, could not open /dev/null: %s", strerror(errno));
936 dbg("version %s", UDEV_VERSION);
939 err("need to be root, exit");
943 /* parse commandline options */
944 for (i = 1 ; i < argc; i++) {
946 if (strcmp(arg, "--daemon") == 0 || strcmp(arg, "-d") == 0) {
947 info("will daemonize");
952 /* init sockets to receive events */
953 if (init_udevd_socket() < 0) {
954 if (errno == EADDRINUSE) {
955 err("another udevd running, exit");
958 err("error initializing udevd socket: %s", strerror(errno));
964 if (init_uevent_netlink_sock() < 0) {
965 err("uevent socket not available");
970 /* parse the rules and keep it in memory */
972 udev_rules_init(&rules, 1);
974 export_initial_seqnum();
982 dbg("daemonized fork running");
985 err("fork of daemon failed: %s", strerror(errno));
989 dbg("child [%u] running, parent exits", pid);
994 /* set scheduling priority for the daemon */
995 setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
1000 /* become session leader */
1002 dbg("our session is %d", sid);
1004 /* OOM_DISABLE == -17 */
1005 fd = open("/proc/self/oom_adj", O_RDWR);
1007 err("error disabling OOM: %s", strerror(errno));
1009 write(fd, "-17", 3);
1013 /* setup signal handler pipe */
1014 retval = pipe(signal_pipe);
1016 err("error getting pipes: %s", strerror(errno));
1020 retval = fcntl(signal_pipe[READ_END], F_GETFL, 0);
1022 err("error fcntl on read pipe: %s", strerror(errno));
1025 retval = fcntl(signal_pipe[READ_END], F_SETFL, retval | O_NONBLOCK);
1027 err("error fcntl on read pipe: %s", strerror(errno));
1031 retval = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
1033 err("error fcntl on write pipe: %s", strerror(errno));
1036 retval = fcntl(signal_pipe[WRITE_END], F_SETFL, retval | O_NONBLOCK);
1038 err("error fcntl on write pipe: %s", strerror(errno));
1042 /* set signal handlers */
1043 memset(&act, 0x00, sizeof(struct sigaction));
1044 act.sa_handler = (void (*)(int)) sig_handler;
1045 sigemptyset(&act.sa_mask);
1046 act.sa_flags = SA_RESTART;
1047 sigaction(SIGINT, &act, NULL);
1048 sigaction(SIGTERM, &act, NULL);
1049 sigaction(SIGCHLD, &act, NULL);
1050 sigaction(SIGHUP, &act, NULL);
1052 /* watch rules directory */
1053 inotify_fd = inotify_init();
1054 if (inotify_fd >= 0)
1055 inotify_add_watch(inotify_fd, udev_rules_filename, IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
1056 else if (errno == ENOSYS)
1057 err("the kernel does not support inotify, udevd can't monitor configuration file changes");
1059 err("inotify_init failed: %s", strerror(errno));
1061 /* maximum limit of forked childs */
1062 value = getenv("UDEVD_MAX_CHILDS");
1064 max_childs = strtoul(value, NULL, 10);
1066 int memsize = mem_size_mb();
1068 max_childs = 128 + (memsize / 4);
1070 max_childs = UDEVD_MAX_CHILDS;
1072 info("initialize max_childs to %u", max_childs);
1074 /* start to throttle forking if maximum number of _running_ childs is reached */
1075 value = getenv("UDEVD_MAX_CHILDS_RUNNING");
1077 max_childs_running = strtoull(value, NULL, 10);
1079 int cpus = cpu_count();
1081 max_childs_running = 8 + (8 * cpus);
1083 max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
1085 info("initialize max_childs_running to %u", max_childs_running);
1087 /* clear environment for forked event processes */
1090 /* export log_priority , as called programs may want to follow that setting */
1091 sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
1095 maxfd = UDEV_MAX(maxfd, uevent_netlink_sock);
1096 maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
1097 maxfd = UDEV_MAX(maxfd, inotify_fd);
1099 while (!udev_exit) {
1100 struct udevd_uevent_msg *msg;
1104 FD_SET(signal_pipe[READ_END], &readfds);
1105 FD_SET(udevd_sock, &readfds);
1106 FD_SET(uevent_netlink_sock, &readfds);
1107 if (inotify_fd >= 0)
1108 FD_SET(inotify_fd, &readfds);
1110 fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
1113 err("error in select: %s", strerror(errno));
1117 /* get control message */
1118 if (FD_ISSET(udevd_sock, &readfds))
1121 /* get netlink message */
1122 if (FD_ISSET(uevent_netlink_sock, &readfds)) {
1123 msg = get_netlink_msg();
1125 msg_queue_insert(msg);
1128 /* received a signal, clear our notification pipe */
1129 if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
1132 read(signal_pipe[READ_END], &buf, sizeof(buf));
1135 /* rules directory inotify watch */
1136 if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
1139 /* discard all possible events, we can just reload the config */
1140 if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes) {
1144 buf = malloc(nbytes);
1146 err("error getting buffer for inotify, disable watching");
1150 read(inotify_fd, buf, nbytes);
1155 /* rules changed, set by inotify or a signal*/
1156 if (reload_config) {
1158 udev_rules_cleanup(&rules);
1159 udev_rules_init(&rules, 1);
1162 /* forked child has returned */
1163 if (sigchilds_waiting) {
1164 sigchilds_waiting = 0;
1171 msg_queue_manager();
1176 udev_rules_cleanup(&rules);
1179 if (signal_pipe[READ_END] >= 0)
1180 close(signal_pipe[READ_END]);
1181 if (signal_pipe[WRITE_END] >= 0)
1182 close(signal_pipe[WRITE_END]);
1184 if (udevd_sock >= 0)
1186 if (inotify_fd >= 0)
1188 if (uevent_netlink_sock >= 0)
1189 close(uevent_netlink_sock);