* udevd.c - hotplug event serializer
*
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
*
*
* This program is free software; you can redistribute it and/or modify it
*
*/
-#include <pthread.h>
#include <stddef.h>
-#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
-#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
+#include <sys/time.h>
#include "list.h"
#include "udev.h"
#include "udevd.h"
#include "logging.h"
-
-unsigned char logname[42];
-static pthread_mutex_t msg_lock;
-static pthread_mutex_t msg_active_lock;
-static pthread_cond_t msg_active;
-static pthread_mutex_t exec_lock;
-static pthread_mutex_t exec_active_lock;
-static pthread_cond_t exec_active;
-static pthread_mutex_t running_lock;
-static pthread_attr_t thr_attr;
static int expected_seqnum = 0;
+volatile static int children_waiting;
+volatile static int msg_q_timeout;
LIST_HEAD(msg_list);
LIST_HEAD(exec_list);
LIST_HEAD(running_list);
+static void exec_queue_manager(void);
+static void msg_queue_manager(void);
+
+#ifdef LOG
+unsigned char logname[42];
+void log_message (int level, const char *format, ...)
+{
+ va_list args;
+
+ va_start(args, format);
+ vsyslog(level, format, args);
+ va_end(args);
+}
+#endif
static void msg_dump_queue(void)
{
struct hotplug_msg *new_msg;
new_msg = malloc(sizeof(struct hotplug_msg));
- if (new_msg == NULL) {
+ if (new_msg == NULL)
dbg("error malloc");
- return NULL;
- }
return new_msg;
}
-static void msg_delete(struct hotplug_msg *msg)
+static void run_queue_delete(struct hotplug_msg *msg)
{
- if (msg != NULL)
- free(msg);
+ list_del(&msg->list);
+ free(msg);
+ exec_queue_manager();
}
/* orders the message in the queue by sequence number */
/* store timestamp of queuing */
msg->queue_time = time(NULL);
- /* signal queue activity to manager */
- pthread_mutex_lock(&msg_active_lock);
- pthread_cond_signal(&msg_active);
- pthread_mutex_unlock(&msg_active_lock);
+ /* run msg queue manager */
+ msg_queue_manager();
return ;
}
/* forks event and removes event from run queue when finished */
-static void *run_threads(void * parm)
+static void udev_run(struct hotplug_msg *msg)
{
pid_t pid;
- struct hotplug_msg *msg;
+ char action[32];
+ char devpath[256];
+ char *env[] = { action, devpath, NULL };
- msg = parm;
- setenv("ACTION", msg->action, 1);
- setenv("DEVPATH", msg->devpath, 1);
+ snprintf(action, sizeof(action), "ACTION=%s", msg->action);
+ snprintf(devpath, sizeof(devpath), "DEVPATH=%s", msg->devpath);
pid = fork();
switch (pid) {
case 0:
/* child */
- execl(UDEV_BIN, "udev", msg->subsystem, NULL);
+ execle(UDEV_BIN, "udev", msg->subsystem, NULL, env);
dbg("exec of child failed");
exit(1);
break;
case -1:
dbg("fork of child failed");
- goto exit;
+ run_queue_delete(msg);
+ break;
default:
- /* wait for exit of child */
- dbg("==> exec seq %d [%d] working at '%s'",
- msg->seqnum, pid, msg->devpath);
- wait(NULL);
- dbg("<== exec seq %d came back", msg->seqnum);
+ /* get SIGCHLD in main loop */
+ dbg("==> exec seq %d [%d] working at '%s'", msg->seqnum, pid, msg->devpath);
+ msg->pid = pid;
}
-
-exit:
- /* remove event from run list */
- pthread_mutex_lock(&running_lock);
- list_del_init(&msg->list);
- pthread_mutex_unlock(&running_lock);
-
- msg_delete(msg);
-
- /* signal queue activity to exec manager */
- pthread_mutex_lock(&exec_active_lock);
- pthread_cond_signal(&exec_active);
- pthread_mutex_unlock(&exec_active_lock);
-
- pthread_exit(0);
}
/* returns already running task with devpath */
static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg)
{
struct hotplug_msg *loop_msg;
- struct hotplug_msg *tmp_msg;
-
- list_for_each_entry_safe(loop_msg, tmp_msg, &running_list, list)
+ list_for_each_entry(loop_msg, &running_list, list)
if (strncmp(loop_msg->devpath, msg->devpath, sizeof(loop_msg->devpath)) == 0)
return loop_msg;
return NULL;
}
-/* queue management executes the events and delays events for the same devpath */
-static void *exec_queue_manager(void * parm)
+/* exec queue management routine executes the events and delays events for the same devpath */
+static void exec_queue_manager()
{
struct hotplug_msg *loop_msg;
struct hotplug_msg *tmp_msg;
struct hotplug_msg *msg;
- pthread_t run_tid;
- while (1) {
- pthread_mutex_lock(&exec_lock);
- list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, list) {
- msg = running_with_devpath(loop_msg);
- if (msg == NULL) {
- /* move event to run list */
- pthread_mutex_lock(&running_lock);
- list_move_tail(&loop_msg->list, &running_list);
- pthread_mutex_unlock(&running_lock);
-
- pthread_create(&run_tid, &thr_attr, run_threads, (void *) loop_msg);
-
- dbg("moved seq %d to running list", loop_msg->seqnum);
- } else {
- dbg("delay seq %d, cause seq %d already working on '%s'",
- loop_msg->seqnum, msg->seqnum, msg->devpath);
- }
+ list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, list) {
+ msg = running_with_devpath(loop_msg);
+ if (!msg) {
+ /* move event to run list */
+ list_move_tail(&loop_msg->list, &running_list);
+ udev_run(loop_msg);
+ dbg("moved seq %d to running list", loop_msg->seqnum);
+ } else {
+ dbg("delay seq %d, cause seq %d already working on '%s'",
+ loop_msg->seqnum, msg->seqnum, msg->devpath);
}
- pthread_mutex_unlock(&exec_lock);
-
- /* wait for activation, new events or childs coming back */
- pthread_mutex_lock(&exec_active_lock);
- pthread_cond_wait(&exec_active, &exec_active_lock);
- pthread_mutex_unlock(&exec_active_lock);
}
}
-/* move message from incoming to exec queue */
-static void msg_move_exec(struct list_head *head)
+static void msg_move_exec(struct hotplug_msg *msg)
{
- list_move_tail(head, &exec_list);
- /* signal queue activity to manager */
- pthread_mutex_lock(&exec_active_lock);
- pthread_cond_signal(&exec_active);
- pthread_mutex_unlock(&exec_active_lock);
+ list_move_tail(&msg->list, &exec_list);
+ exec_queue_manager();
+ expected_seqnum = msg->seqnum+1;
+ dbg("moved seq %d to exec, next expected is %d",
+ msg->seqnum, expected_seqnum);
}
-/* queue management thread handles the timeouts and dispatches the events */
-static void *msg_queue_manager(void * parm)
+/* msg queue management routine handles the timeouts and dispatches the events */
+static void msg_queue_manager()
{
struct hotplug_msg *loop_msg;
struct hotplug_msg *tmp_msg;
time_t msg_age = 0;
- struct timespec tv;
- while (1) {
- dbg("msg queue manager, next expected is %d", expected_seqnum);
- pthread_mutex_lock(&msg_lock);
- pthread_mutex_lock(&exec_lock);
+ dbg("msg queue manager, next expected is %d", expected_seqnum);
recheck:
- list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, list) {
- /* move event with expected sequence to the exec list */
- if (loop_msg->seqnum == expected_seqnum) {
- msg_move_exec(&loop_msg->list);
- expected_seqnum++;
- dbg("moved seq %d to exec, next expected is %d",
- loop_msg->seqnum, expected_seqnum);
- continue;
- }
-
- /* move event with expired timeout to the exec list */
- msg_age = time(NULL) - loop_msg->queue_time;
- if (msg_age > EVENT_TIMEOUT_SEC-1) {
- msg_move_exec(&loop_msg->list);
- expected_seqnum = loop_msg->seqnum+1;
- dbg("moved seq %d to exec, reset next expected to %d",
- loop_msg->seqnum, expected_seqnum);
- goto recheck;
- } else {
- break;
- }
+ list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, list) {
+ /* move event with expected sequence to the exec list */
+ if (loop_msg->seqnum == expected_seqnum) {
+ msg_move_exec(loop_msg);
+ continue;
}
- msg_dump_queue();
- pthread_mutex_unlock(&exec_lock);
- pthread_mutex_unlock(&msg_lock);
-
- /* wait until queue gets active or next message timeout expires */
- pthread_mutex_lock(&msg_active_lock);
-
- if (list_empty(&msg_list) == 0) {
- tv.tv_sec = time(NULL) + EVENT_TIMEOUT_SEC - msg_age;
- tv.tv_nsec = 0;
- dbg("next event expires in %li seconds",
- EVENT_TIMEOUT_SEC - msg_age);
- pthread_cond_timedwait(&msg_active, &msg_active_lock, &tv);
+ /* move event with expired timeout to the exec list */
+ msg_age = time(NULL) - loop_msg->queue_time;
+ if (msg_age > EVENT_TIMEOUT_SEC-1) {
+ msg_move_exec(loop_msg);
+ goto recheck;
} else {
- pthread_cond_wait(&msg_active, &msg_active_lock);
+ break;
}
- pthread_mutex_unlock(&msg_active_lock);
+ }
+
+ msg_dump_queue();
+
+ if (list_empty(&msg_list) == 0) {
+ /* set timeout for remaining queued events */
+ struct itimerval itv = {{0, 0}, {EVENT_TIMEOUT_SEC - msg_age, 0}};
+ dbg("next event expires in %li seconds",
+ EVENT_TIMEOUT_SEC - msg_age);
+ setitimer(ITIMER_REAL, &itv, 0);
}
}
-/* every connect creates a thread which gets the msg, queues it and exits */
-static void *client_threads(void * parm)
+/* receive the msg, do some basic sanity checks, and queue it */
+static void handle_msg(int sock)
{
- int sock;
struct hotplug_msg *msg;
int retval;
-
- sock = (int) parm;
+ struct msghdr smsg;
+ struct cmsghdr *cmsg;
+ struct iovec iov;
+ struct ucred *cred;
+ char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
msg = msg_create();
if (msg == NULL) {
dbg("unable to store message");
- goto exit;
+ return;
}
- retval = recv(sock, msg, sizeof(struct hotplug_msg), 0);
+ iov.iov_base = msg;
+ iov.iov_len = sizeof(struct hotplug_msg);
+
+ memset(&smsg, 0x00, sizeof(struct msghdr));
+ smsg.msg_iov = &iov;
+ smsg.msg_iovlen = 1;
+ smsg.msg_control = cred_msg;
+ smsg.msg_controllen = sizeof(cred_msg);
+
+ retval = recvmsg(sock, &smsg, 0);
if (retval < 0) {
- dbg("unable to receive message");
- goto exit;
+ if (errno != EINTR)
+ dbg("unable to receive message");
+ return;
+ }
+ cmsg = CMSG_FIRSTHDR(&smsg);
+ cred = (struct ucred *) CMSG_DATA(cmsg);
+
+ if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
+ dbg("no sender credentials received, message ignored");
+ goto skip;
+ }
+
+ if (cred->uid != 0) {
+ dbg("sender uid=%i, message ignored", cred->uid);
+ goto skip;
}
if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
dbg("message magic '%s' doesn't match, ignore it", msg->magic);
- msg_delete(msg);
- goto exit;
+ goto skip;
}
- pthread_mutex_lock(&msg_lock);
- msg_queue_insert(msg);
- pthread_mutex_unlock(&msg_lock);
+ /* if no seqnum is given, we move straight to exec queue */
+ if (msg->seqnum == -1) {
+ list_add(&msg->list, &exec_list);
+ exec_queue_manager();
+ } else {
+ msg_queue_insert(msg);
+ }
+ return;
-exit:
- close(sock);
- pthread_exit(0);
+skip:
+ free(msg);
+ return;
}
static void sig_handler(int signum)
switch (signum) {
case SIGINT:
case SIGTERM:
- unlink(UDEVD_LOCK);
- unlink(UDEVD_SOCK);
exit(20 + signum);
break;
+ case SIGALRM:
+ msg_q_timeout = 1;
+ break;
+ case SIGCHLD:
+ children_waiting = 1;
+ break;
default:
dbg("unhandled signal");
}
}
-static int one_and_only(void)
+static void udev_done(int pid)
{
- char string[50];
- int lock_file;
-
- lock_file = open(UDEVD_LOCK, O_RDWR | O_CREAT, 0x640);
- if (lock_file < 0)
- return -1;
-
- /* see if we can lock */
- if (lockf(lock_file, F_TLOCK, 0) < 0) {
- dbg("file is already locked, exit");
- close(lock_file);
- return -1;
- }
-
- snprintf(string, sizeof(string), "%d\n", getpid());
- write(lock_file, string, strlen(string));
+ /* find msg associated with pid and delete it */
+ struct hotplug_msg *msg;
- return 0;
+ list_for_each_entry(msg, &running_list, list) {
+ if (msg->pid == pid) {
+ dbg("<== exec seq %d came back", msg->seqnum);
+ run_queue_delete(msg);
+ return;
+ }
+ }
}
int main(int argc, char *argv[])
{
int ssock;
- int csock;
struct sockaddr_un saddr;
- struct sockaddr_un caddr;
- socklen_t clen;
- pthread_t cli_tid;
- pthread_t mgr_msg_tid;
- pthread_t mgr_exec_tid;
+ socklen_t addrlen;
int retval;
+ const int on = 1;
+ struct sigaction act;
init_logging("udevd");
- /* only let one version of the daemon run at any one time */
- if (one_and_only() != 0)
- exit(0);
+ if (getuid() != 0) {
+ dbg("need to be root, exit");
+ exit(1);
+ }
- signal(SIGINT, sig_handler);
- signal(SIGTERM, sig_handler);
+ /* set signal handler */
+ act.sa_handler = sig_handler;
+ sigemptyset (&act.sa_mask);
+ act.sa_flags = SA_RESTART;
+ sigaction(SIGINT, &act, NULL);
+ sigaction(SIGTERM, &act, NULL);
+
+ /* we want these two to interrupt system calls */
+ act.sa_flags = 0;
+ sigaction(SIGALRM, &act, NULL);
+ sigaction(SIGCHLD, &act, NULL);
memset(&saddr, 0x00, sizeof(saddr));
saddr.sun_family = AF_LOCAL;
- strcpy(saddr.sun_path, UDEVD_SOCK);
+ /* use abstract namespace for socket path */
+ strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH);
+ addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
- unlink(UDEVD_SOCK);
- ssock = socket(AF_LOCAL, SOCK_STREAM, 0);
+ ssock = socket(AF_LOCAL, SOCK_DGRAM, 0);
if (ssock == -1) {
- dbg("error getting socket");
+ dbg("error getting socket, exit");
exit(1);
}
- retval = bind(ssock, &saddr, sizeof(saddr));
- if (retval < 0) {
- dbg("bind failed\n");
- goto exit;
- }
-
- retval = listen(ssock, SOMAXCONN);
+ /* the bind takes care of ensuring only one copy running */
+ retval = bind(ssock, (struct sockaddr *) &saddr, addrlen);
if (retval < 0) {
- dbg("listen failed\n");
+ dbg("bind failed, exit");
goto exit;
}
- pthread_mutex_init(&msg_lock, NULL);
- pthread_mutex_init(&msg_active_lock, NULL);
- pthread_mutex_init(&exec_lock, NULL);
- pthread_mutex_init(&exec_active_lock, NULL);
- pthread_mutex_init(&running_lock, NULL);
+ /* enable receiving of the sender credentials */
+ setsockopt(ssock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
- /* set default attributes for created threads */
- pthread_attr_init(&thr_attr);
- pthread_attr_setdetachstate(&thr_attr, PTHREAD_CREATE_DETACHED);
- pthread_attr_setstacksize(&thr_attr, 16 * 1024);
+ while (1) {
+ handle_msg(ssock);
- /* init queue management */
- pthread_create(&mgr_msg_tid, &thr_attr, msg_queue_manager, NULL);
- pthread_create(&mgr_exec_tid, &thr_attr, exec_queue_manager, NULL);
+ while(msg_q_timeout) {
+ msg_q_timeout = 0;
+ msg_queue_manager();
+ }
- clen = sizeof(caddr);
- /* main loop */
- while (1) {
- csock = accept(ssock, &caddr, &clen);
- if (csock < 0) {
- dbg("client accept failed\n");
- continue;
+ while(children_waiting) {
+ children_waiting = 0;
+ /* reap all dead children */
+ while(1) {
+ int pid = waitpid(-1, 0, WNOHANG);
+ if ((pid == -1) || (pid == 0))
+ break;
+ udev_done(pid);
+ }
}
- pthread_create(&cli_tid, &thr_attr, client_threads, (void *) csock);
}
exit:
close(ssock);
- unlink(UDEVD_SOCK);
exit(1);
}
~ianmdlvl / elogind.git / blobdiff