X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevsend.c;h=f92ee2b5d8286aa539c575355ee76368b2d43ee6;hp=748c8f22173e8d17a621bc4aa605f158f43f5bc9;hb=35b7d88c0dab4c1104c127ddd644db22307949c9;hpb=90c210eb6bfc2ae294202fffb080315f3c47a57b

diff --git a/udevsend.c b/udevsend.c
index 748c8f221..f92ee2b5d 100644
--- a/udevsend.c
+++ b/udevsend.c
@@ -29,8 +29,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
+#include <time.h>
+#include <wait.h>
 
 #include "udev.h"
+#include "udev_version.h"
 #include "udevd.h"
 #include "logging.h"
 
@@ -58,32 +62,59 @@ 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));
+	msg->mtype = HOTPLUGMSGTYPE;
+	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 msqid_ds msg_queue;
+	struct hotplug_msg message;
 	char *action;
 	char *devpath;
 	char *subsystem;
@@ -91,6 +122,8 @@ int main(int argc, char* argv[])
 	int seq;
 	int retval = -EINVAL;
 	int size;
+	int loop;
+	struct timespec tspec;
 
 	subsystem = argv[1];
 	if (subsystem == NULL) {
@@ -118,35 +151,40 @@ int main(int argc, char* argv[])
 	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);
+	key = ftok(UDEVD_BIN, IPC_KEY_ID);
+	dbg("using ipc queue 0x%0x", key);
+	size =  build_hotplugmsg(&message, action, devpath, subsystem, seq);
 	msgid = msgget(key, IPC_CREAT);
 	if (msgid == -1) {
 		dbg("error open ipc queue");
 		goto exit;
 	}
 
-	/* 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);
+	retval = msgsnd(msgid, &message, size, 0);
 	if (retval == -1) {
 		dbg("error sending ipc message");
 		goto exit;
 	}
-	return 0;
 
-exit:
-	if (retval > 0)
-		retval = 0;
+	/* get state of ipc queue */
+	tspec.tv_sec = 0;
+	tspec.tv_nsec = 10000000;  /* 10 millisec */
+	loop = UDEVSEND_RETRY_COUNT;
+	while (loop--) {
+		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)
+			goto exit;
+		nanosleep(&tspec, NULL);
+	}
+
+	info("message is still in the ipc queue, starting daemon...");
+	retval = start_daemon();
 
+exit:
 	return retval;
 }