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/*
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/un.h>
#include <time.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <unistd.h>
#include <linux/stddef.h>
#include "udev.h"
#include "udev_lib.h"
#include "udev_version.h"
#include "udevd.h"
#include "logging.h"
#ifdef LOG
unsigned char logname[LOGNAME_SIZE];
void log_message (int level, const char *format, ...)
{
va_list args;
va_start(args, format);
vsyslog(level, format, args);
va_end(args);
}
#endif
static int start_daemon(void)
{
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;
}
static void run_udev(const char *subsystem)
{
pid_t pid;
pid = fork();
switch (pid) {
case 0:
/* child */
execl(UDEV_BIN, "udev", subsystem, NULL);
dbg("exec of child failed");
exit(1);
break;
case -1:
dbg("fork of child failed");
break;
default:
wait(NULL);
}
}
int main(int argc, char* argv[])
{
struct hotplug_msg msg;
char *action;
char *devpath;
char *subsystem;
char *seqnum;
unsigned long long seq;
int retval = 1;
int loop;
struct timespec tspec;
int sock = -1;
struct sockaddr_un saddr;
socklen_t addrlen;
int started_daemon = 0;
init_logging("udevsend");
dbg("version %s", UDEV_VERSION);
subsystem = get_subsystem(argv[1]);
if (subsystem == NULL) {
dbg("no subsystem");
goto exit;
}
dbg("subsystem = '%s'", subsystem);
devpath = get_devpath();
if (devpath == NULL) {
dbg("no devpath");
goto exit;
}
dbg("DEVPATH = '%s'", devpath);
action = get_action();
if (action == NULL) {
dbg("no action");
goto exit;
}
dbg("ACTION = '%s'", action);
seqnum = get_seqnum();
if (seqnum == NULL)
seq = 0;
else
seq = strtoull(seqnum, NULL, 10);
dbg("SEQNUM = '%llu'", seq);
sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
if (sock == -1) {
dbg("error getting socket");
goto fallback;
}
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(&msg, 0x00, sizeof(struct hotplug_msg));
strcpy(msg.magic, UDEV_MAGIC);
msg.seqnum = seq;
strfieldcpy(msg.action, action);
strfieldcpy(msg.devpath, devpath);
strfieldcpy(msg.subsystem, subsystem);
/* If we can't send, try to start daemon and resend message */
loop = UDEVSEND_CONNECT_RETRY;
while (loop--) {
retval = sendto(sock, &msg, sizeof(struct hotplug_msg), 0,
(struct sockaddr *)&saddr, addrlen);
if (retval != -1) {
retval = 0;
goto exit;
}
if (errno != ECONNREFUSED) {
dbg("error sending message");
goto fallback;
}
if (!started_daemon) {
info("starting udevd daemon");
retval = start_daemon();
if (retval) {
info("error starting daemon");
goto fallback;
}
dbg("daemon started");
started_daemon = 1;
} else {
dbg("retry to connect %d", UDEVSEND_CONNECT_RETRY - loop);
tspec.tv_sec = 0;
tspec.tv_nsec = 100000000; /* 100 millisec */
nanosleep(&tspec, NULL);
}
}
fallback:
info("unable to connect to event daemon, try to call udev directly");
run_udev(subsystem);
exit:
if (sock != -1)
close(sock);
return retval;
}
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