chiark / gitweb /
udevd: track exit status of event process
[elogind.git] / udevsend.c
index 748c8f2..d0cfc2a 100644 (file)
@@ -1,12 +1,9 @@
 /*
  * udevsend.c
  *
- * Userspace devfs
- *
  * Copyright (C) 2004 Ling, Xiaofeng <xiaofeng.ling@intel.com>
  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
  *
- *
  *     This program is free software; you can redistribute it and/or modify it
  *     under the terms of the GNU General Public License as published by the
  *     Free Software Foundation version 2 of the License.
  *
  */
 
-#include <sys/types.h>
-#include <sys/ipc.h>
-#include <sys/msg.h>
-#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stddef.h>
+#include <unistd.h>
 #include <string.h>
+#include <time.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sys/un.h>
+#include <linux/stddef.h>
 
 #include "udev.h"
+#include "udev_version.h"
 #include "udevd.h"
 #include "logging.h"
 
-static inline char *get_action(void)
-{
-       char *action;
+/* global variables */
+static int sock = -1;
 
-       action = getenv("ACTION");
-       return action;
-}
-
-static inline char *get_devpath(void)
+#ifdef USE_LOG
+void log_message (int priority, const char *format, ...)
 {
-       char *devpath;
-
-       devpath = getenv("DEVPATH");
-       return devpath;
-}
+       va_list args;
 
-static inline char *get_seqnum(void)
-{
-       char *seqnum;
+       if (priority > udev_log_priority)
+               return;
 
-       seqnum = getenv("SEQNUM");
-       return seqnum;
-}
-
-static int build_hotplugmsg(struct hotplug_msg **ppmsg, char *action,
-                           char *devpath, char *subsystem, int seqnum)
-{
-       struct hotplug_msg *pmsg;
-
-       pmsg = malloc(sizeof(struct hotplug_msg));
-       pmsg->mtype = HOTPLUGMSGTYPE;
-       pmsg->seqnum = seqnum;
-       strncpy(pmsg->action, action, 8);
-       strncpy(pmsg->devpath, devpath, 128);
-       strncpy(pmsg->subsystem, subsystem, 16);
-       *ppmsg = pmsg;
-       return sizeof(struct hotplug_msg);
+       va_start(args, format);
+       vsyslog(priority, format, args);
+       va_end(args);
 }
+#endif
 
-static void free_hotplugmsg(struct hotplug_msg *pmsg)
+static int start_daemon(void)
 {
-       free(pmsg);
+       pid_t pid;
+       pid_t child_pid;
+       char *const argv[] = { "udevd", NULL };
+       char *const envp[] = { NULL };
+
+       pid = fork();
+       switch (pid) {
+       case 0:
+               /* helper child */
+               child_pid = fork();
+               switch (child_pid) {
+               case 0:
+                       /* daemon with empty environment */
+                       close(sock);
+                       execve(UDEVD_BIN, argv, envp);
+                       err("exec of daemon failed: %s", strerror(errno));
+                       _exit(1);
+               case -1:
+                       err("fork of daemon failed: %s", strerror(errno));
+                       return -1;
+               default:
+                       exit(0);
+               }
+               break;
+       case -1:
+               err("fork of helper failed: %s", strerror(errno));
+               return -1;
+       default:
+               waitpid(pid, NULL, 0);
+       }
+       return 0;
 }
 
-int main(int argc, char* argv[])
+int main(int argc, char *argv[], char *envp[])
 {
-       int msgid;
-       key_t key;
-       struct msqid_ds  msg_queue;
-       struct msgbuf *pmsg;
-       char *action;
-       char *devpath;
-       char *subsystem;
-       char *seqnum;
-       int seq;
-       int retval = -EINVAL;
-       int size;
-
-       subsystem = argv[1];
-       if (subsystem == NULL) {
-               dbg("no subsystem");
+       static struct udevd_msg usend_msg;
+       int usend_msg_len;
+       int i;
+       int loop;
+       struct sockaddr_un saddr;
+       socklen_t addrlen;
+       int bufpos = 0;
+       int retval = 1;
+       int started_daemon = 0;
+       const char *subsystem = NULL;
+
+       logging_init("udevsend");
+#ifdef USE_LOG
+       udev_init_config();
+#endif
+       dbg("version %s", UDEV_VERSION);
+
+       sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
+       if (sock == -1) {
+               err("error getting socket: %s", strerror(errno));
                goto exit;
        }
 
-       devpath = get_devpath();
-       if (devpath == NULL) {
-               dbg("no devpath");
-               goto exit;
+       memset(&saddr, 0x00, sizeof(struct sockaddr_un));
+       saddr.sun_family = AF_LOCAL;
+       /* 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;
+
+       memset(&usend_msg, 0x00, sizeof(struct udevd_msg));
+       strcpy(usend_msg.magic, UDEV_MAGIC);
+       usend_msg.type = UDEVD_UEVENT_UDEVSEND;
+
+       /* copy all keys to send buffer */
+       for (i = 0; envp[i]; i++) {
+               const char *key;
+               int keylen;
+
+               key = envp[i];
+               keylen = strlen(key);
+
+               /* prevent loops in the scripts we execute */
+               if (strncmp(key, "UDEVD_EVENT=", 12) == 0) {
+                       dbg("seems that the event source is not the kernel, just exit");
+                       goto exit;
+               }
+
+               if (bufpos + keylen >= UEVENT_BUFFER_SIZE-1) {
+                       err("environment buffer too small, probably not called by the kernel");
+                       continue;
+               }
+
+               /* remember the SUBSYSTEM */
+               if (strncmp(key, "SUBSYSTEM=", 10) == 0)
+                       subsystem = &key[10];
+
+               dbg("add '%s' to env[%i] buffer", key, i);
+               strcpy(&usend_msg.envbuf[bufpos], key);
+               bufpos += keylen + 1;
        }
-
-       action = get_action();
-       if (action == NULL) {
-               dbg("no action");
-               goto exit;
+       /* older kernels passed the SUBSYSTEM only as the first argument */
+       if (!subsystem && argc == 2) {
+               bufpos += sprintf(&usend_msg.envbuf[bufpos], "SUBSYSTEM=%s", argv[1]) + 1;
+               dbg("add 'SUBSYSTEM=%s' to env[%i] buffer from argv", argv[1], i);
        }
 
-       seqnum = get_seqnum();
-       if (seqnum == NULL) {
-               dbg("no seqnum");
-               goto exit;
-       }
-       seq = atoi(seqnum);
-
-       /* create ipc message queue or get id of our existing one */
-       key = ftok(DEFAULT_EXEC_PROGRAM, IPC_KEY_ID);
-       size =  build_hotplugmsg( (struct hotplug_msg**) &pmsg, action, devpath, subsystem, seq);
-       msgid = msgget(key, IPC_CREAT);
-       if (msgid == -1) {
-               dbg("error open ipc queue");
-               goto exit;
+       usend_msg_len = offsetof(struct udevd_msg, envbuf) + bufpos;
+       dbg("usend_msg_len=%i", usend_msg_len);
+
+       /* If we can't send, try to start daemon and resend message */
+       loop = UDEVSEND_WAIT_MAX_SECONDS * UDEVSEND_WAIT_LOOP_PER_SECOND;
+       while (--loop) {
+               retval = sendto(sock, &usend_msg, usend_msg_len, 0, (struct sockaddr *)&saddr, addrlen);
+               if (retval != -1) {
+                       retval = 0;
+                       goto exit;
+               }
+
+               if (errno != ECONNREFUSED) {
+                       err("error sending message: %s", strerror(errno));
+                       goto exit;
+               }
+
+               if (!started_daemon) {
+                       info("try to start udevd daemon");
+                       retval = start_daemon();
+                       if (retval) {
+                               dbg("error starting daemon");
+                               goto exit;
+                       }
+                       dbg("udevd daemon started");
+                       started_daemon = 1;
+               } else {
+                       dbg("retry to connect %d", UDEVSEND_WAIT_MAX_SECONDS * UDEVSEND_WAIT_LOOP_PER_SECOND - loop);
+                       usleep(1000 * 1000 / UDEVSEND_WAIT_LOOP_PER_SECOND);
+               }
        }
 
-       /* get state of ipc queue */
-       retval = msgctl(msgid, IPC_STAT, &msg_queue);
-       if (retval == -1) {
-               dbg("error getting info on ipc queue");
-               goto exit;
-       }
-       if (msg_queue.msg_qnum > 0)
-               dbg("%li messages already in the ipc queue", msg_queue.msg_qnum);
-
-       /* send ipc message to the daemon */
-       retval = msgsnd(msgid, pmsg, size, 0);
-       free_hotplugmsg( (struct hotplug_msg*) pmsg);
-       if (retval == -1) {
-               dbg("error sending ipc message");
-               goto exit;
-       }
-       return 0;
-
 exit:
-       if (retval > 0)
-               retval = 0;
+       if (sock != -1)
+               close(sock);
+
+       logging_close();
 
        return retval;
 }