chiark / gitweb /
[PATCH] fix log option code so that it actually works for all udev programs.
[elogind.git] / udevd.c
diff --git a/udevd.c b/udevd.c
index 3ce8c8b..476cb64 100644 (file)
--- a/udevd.c
+++ b/udevd.c
@@ -2,6 +2,7 @@
  * 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
@@ -19,7 +20,6 @@
  *
  */
 
-#include <pthread.h>
 #include <stddef.h>
 #include <sys/wait.h>
 #include <signal.h>
@@ -32,6 +32,7 @@
 #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);
+
+unsigned char logname[42];
+
+int log_ok(void)
+{
+       return 1;
+}
 
 static void msg_dump_queue(void)
 {
@@ -75,17 +77,16 @@ static struct hotplug_msg *msg_create(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 */
@@ -103,21 +104,16 @@ static void msg_queue_insert(struct hotplug_msg *msg)
        /* 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;
-
-       msg = parm;
        setenv("ACTION", msg->action, 1);
        setenv("DEVPATH", msg->devpath, 1);
 
@@ -131,190 +127,124 @@ static void *run_threads(void * parm)
                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);
        }
 }
 
-static void exec_queue_activate(void)
-{
-       pthread_mutex_lock(&exec_active_lock);
-       pthread_cond_signal(&exec_active);
-       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);
-       exec_queue_activate();
+       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;
-
        msg = msg_create();
        if (msg == NULL) {
                dbg("unable to store message");
-               goto exit;
+               return;
        }
 
        retval = recv(sock, msg, sizeof(struct hotplug_msg), 0);
        if (retval <  0) {
-               dbg("unable to receive message");
-               goto exit;
+               if (errno != EINTR)
+                       dbg("unable to receive message");
+               return;
        }
-
+       
        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;
+               free(msg);
+               return;
        }
 
        /* if no seqnum is given, we move straight to exec queue */
-       if (msg->seqnum == 0) {
-               pthread_mutex_lock(&exec_lock);
+       if (msg->seqnum == -1) {
                list_add(&msg->list, &exec_list);
-               exec_queue_activate();
-               pthread_mutex_unlock(&exec_lock);
+               exec_queue_manager();
        } else {
-               pthread_mutex_lock(&msg_lock);
                msg_queue_insert(msg);
-               pthread_mutex_unlock(&msg_lock);
        }
-
-exit:
-       close(sock);
-       pthread_exit(0);
 }
 
 static void sig_handler(int signum)
@@ -324,28 +254,48 @@ static void sig_handler(int signum)
                case SIGTERM:
                        exit(20 + signum);
                        break;
+               case SIGALRM:
+                       msg_q_timeout = 1;
+                       break;
+               case SIGCHLD:
+                       children_waiting = 1;
+                       break;
                default:
                        dbg("unhandled signal");
        }
 }
 
+static void udev_done(int pid)
+{
+       /* find msg associated with pid and delete it */
+       struct hotplug_msg *msg;
+
+       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 addrlen;
-       socklen_t clen;
-       pthread_t cli_tid;
-       pthread_t mgr_msg_tid;
-       pthread_t mgr_exec_tid;
        int retval;
 
        init_logging("udevd");
 
        signal(SIGINT, sig_handler);
        signal(SIGTERM, sig_handler);
+       signal(SIGALRM, sig_handler);
+       signal(SIGCHLD, sig_handler);
+
+       /* we want these two to interrupt system calls */
+       siginterrupt(SIGALRM, 1);
+       siginterrupt(SIGCHLD, 1);
 
        memset(&saddr, 0x00, sizeof(saddr));
        saddr.sun_family = AF_LOCAL;
@@ -353,48 +303,37 @@ int main(int argc, char *argv[])
        strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH);
        addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
 
-       ssock = socket(AF_LOCAL, SOCK_STREAM, 0);
+       ssock = socket(AF_LOCAL, SOCK_DGRAM, 0);
        if (ssock == -1) {
                dbg("error getting socket");
                exit(1);
        }
 
+       /* the bind takes care of ensuring only one copy running */
        retval = bind(ssock, &saddr, addrlen);
        if (retval < 0) {
                dbg("bind failed\n");
                goto exit;
        }
 
-       retval = listen(ssock, SOMAXCONN);
-       if (retval < 0) {
-               dbg("listen failed\n");
-               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);
-
-       /* 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);