chiark / gitweb /
[PATCH] make udevsend binary even smaller
[elogind.git] / udevsend.c
index 37afaf5..d3c74dd 100644 (file)
  */
 
 #include <sys/types.h>
-#include <sys/ipc.h>
-#include <sys/msg.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sys/un.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
+#include <time.h>
 
 #include "udev.h"
+#include "udev_version.h"
 #include "udevd.h"
 #include "logging.h"
 
+unsigned char logname[42];
+
 static inline char *get_action(void)
 {
        char *action;
@@ -58,32 +64,55 @@ static inline char *get_seqnum(void)
        return seqnum;
 }
 
-static int build_hotplugmsg(struct hotplug_msg **ppmsg, char *action,
+static int build_hotplugmsg(struct hotplug_msg *msg, 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;
+       memset(msg, 0x00, sizeof(*msg));
+       strfieldcpy(msg->magic, UDEV_MAGIC);
+       msg->seqnum = seqnum;
+       strncpy(msg->action, action, 8);
+       strncpy(msg->devpath, devpath, 128);
+       strncpy(msg->subsystem, subsystem, 16);
        return sizeof(struct hotplug_msg);
 }
 
-static void free_hotplugmsg(struct hotplug_msg *pmsg)
+static int start_daemon(void)
 {
-       free(pmsg);
+       pid_t pid;
+       pid_t child_pid;
+
+       pid = fork();
+       switch (pid) {
+       case 0:
+               /* helper child */
+               child_pid = fork();
+               switch (child_pid) {
+               case 0:
+                       /* daemon */
+                       setsid();
+                       chdir("/");
+                       execl(UDEVD_BIN, "udevd", NULL);
+                       dbg("exec of daemon failed");
+                       exit(1);
+               case -1:
+                       dbg("fork of daemon failed");
+                       return -1;
+               default:
+                       exit(0);
+               }
+               break;
+       case -1:
+               dbg("fork of helper failed");
+               return -1;
+       default:
+               wait(NULL);
+       }
+       return 0;
 }
 
 int main(int argc, char* argv[])
 {
-       int msgid;
-       key_t key;
-       struct msqid_ds  msg_queue;
-       struct msgbuf *pmsg;
+       struct hotplug_msg message;
        char *action;
        char *devpath;
        char *subsystem;
@@ -91,6 +120,14 @@ int main(int argc, char* argv[])
        int seq;
        int retval = -EINVAL;
        int size;
+       int loop;
+       struct timespec tspec;
+       int sock;
+       struct sockaddr_un saddr;
+
+#ifdef DEBUG
+       init_logging("udevsend");
+#endif
 
        subsystem = argv[1];
        if (subsystem == NULL) {
@@ -115,38 +152,60 @@ int main(int argc, char* argv[])
                dbg("no seqnum");
                goto exit;
        }
-
        seq = atoi(seqnum);
-       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("open ipc queue error");
+
+       sock = socket(AF_LOCAL, SOCK_STREAM, 0);
+       if (sock == -1) {
+               dbg("error getting socket");
                goto exit;
        }
 
-       /* get state of queue */
-       retval = msgctl(msgid, IPC_STAT, &msg_queue);
-       if (retval == -1) {
-               dbg("error getting info on ipc queue");
-               goto exit;
+       memset(&saddr, 0x00, sizeof(saddr));
+       saddr.sun_family = AF_LOCAL;
+       strcpy(saddr.sun_path, UDEVD_SOCK);
+
+       /* try to connect, if it fails start daemon */
+       retval = connect(sock, (struct sockaddr *) &saddr, sizeof(saddr));
+       if (retval != -1) {
+               goto send;
+       } else {
+               dbg("connect failed, try starting daemon...");
+               retval = start_daemon();
+               if (retval == 0) {
+                       dbg("daemon started");
+               } else {
+                       dbg("error starting daemon");
+                       goto exit;
+               }
+       }
+
+       /* try to connect while daemon to starts */
+       tspec.tv_sec = 0;
+       tspec.tv_nsec = 100000000;  /* 100 millisec */
+       loop = UDEVSEND_CONNECT_RETRY;
+       while (loop--) {
+               retval = connect(sock, (struct sockaddr *) &saddr, sizeof(saddr));
+               if (retval != -1)
+                       goto send;
+               else
+                       dbg("retry to connect %d",
+                           UDEVSEND_CONNECT_RETRY - loop);
+               nanosleep(&tspec, NULL);
        }
-       if (msg_queue.msg_qnum > 0)
-               dbg("%li messages already in the ipc queue", msg_queue.msg_qnum);
-
-       retval = msgsnd(msgid, pmsg, size, 0);
-       free_hotplugmsg( (struct hotplug_msg*) pmsg);
-       if (retval == -1)
-       {
-               dbg("send ipc message error");
+       dbg("error connecting to daemon, start daemon failed");
+       goto exit;
+
+send:
+       size = build_hotplugmsg(&message, action, devpath, subsystem, seq);
+       retval = send(sock, &message, size, 0);
+       if (retval == -1) {
+               dbg("error sending message");
+               close (sock);
                goto exit;
        }
+       close (sock);
        return 0;
 
 exit:
-       if (retval > 0)
-               retval = 0;
-
-       return retval;
+       return 1;
 }