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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_version.h"
#include "udevd.h"
#include "logging.h"
/* global variables */
static int sock = -1;
#ifdef USE_LOG
void log_message (int priority, const char *format, ...)
{
va_list args;
if (priority > udev_log_priority)
return;
va_start(args, format);
vsyslog(priority, format, args);
va_end(args);
}
#endif
static int start_daemon(void)
{
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");
_exit(1);
case -1:
err("fork of daemon failed");
return -1;
default:
exit(0);
}
break;
case -1:
err("fork of helper failed");
return -1;
default:
waitpid(pid, NULL, 0);
}
return 0;
}
static void run_udev(const char *subsystem)
{
char *const argv[] = { "udev", (char *)subsystem, NULL };
pid_t pid;
pid = fork();
switch (pid) {
case 0:
/* child */
execv(UDEV_BIN, argv);
err("exec of udev child failed");
_exit(1);
break;
case -1:
err("fork of udev child failed");
break;
default:
waitpid(pid, NULL, 0);
}
}
int main(int argc, char *argv[], char *envp[])
{
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");
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(&usend_msg, 0x00, sizeof(struct udevd_msg));
strcpy(usend_msg.magic, UDEV_MAGIC);
usend_msg.type = UDEVD_UEVENT;
/* 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;
}
/* 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);
}
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 fallback;
}
if (!started_daemon) {
info("try to start udevd daemon");
retval = start_daemon();
if (retval) {
dbg("error starting daemon");
goto fallback;
}
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);
}
}
fallback:
err("unable to connect to event daemon, try to call udev directly");
run_udev(subsystem);
exit:
if (sock != -1)
close(sock);
logging_close();
return retval;
}
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