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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 <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <linux/stddef.h>
#include "udev.h"
#include "udev_version.h"
#include "udevd.h"
#include "logging.h"
unsigned char logname[42];
int log_ok(void)
{
return 1;
}
static inline char *get_action(void)
{
char *action;
action = getenv("ACTION");
return action;
}
static inline char *get_devpath(void)
{
char *devpath;
devpath = getenv("DEVPATH");
return devpath;
}
static inline char *get_seqnum(void)
{
char *seqnum;
seqnum = getenv("SEQNUM");
return seqnum;
}
static int build_hotplugmsg(struct hotplug_msg *msg, char *action,
char *devpath, char *subsystem, int seqnum)
{
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 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;
}
int main(int argc, char* argv[])
{
struct hotplug_msg msg;
char *action;
char *devpath;
char *subsystem;
char *seqnum;
int seq;
int retval = 1;
int size;
int loop;
struct timespec tspec;
int sock;
struct sockaddr_un saddr;
socklen_t addrlen;
int started_daemon = 0;
struct iovec iov;
struct msghdr smsg;
char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
struct cmsghdr *cmsg;
struct ucred *cred;
#ifdef DEBUG
init_logging("udevsend");
#endif
subsystem = argv[1];
if (subsystem == NULL) {
dbg("no subsystem");
goto exit;
}
devpath = get_devpath();
if (devpath == NULL) {
dbg("no devpath");
goto exit;
}
action = get_action();
if (action == NULL) {
dbg("no action");
goto exit;
}
seqnum = get_seqnum();
if (seqnum == NULL)
seq = -1;
else
seq = atoi(seqnum);
sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
if (sock == -1) {
dbg("error getting socket");
goto exit;
}
memset(&saddr, 0x00, sizeof(saddr));
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;
size = build_hotplugmsg(&msg, action, devpath, subsystem, seq);
/* prepare message with credentials to authenticate ourself */
iov.iov_base = &msg;
iov.iov_len = size;
smsg.msg_name = &saddr;
smsg.msg_namelen = addrlen;
smsg.msg_iov = &iov;
smsg.msg_iovlen = 1;
smsg.msg_control = cred_msg;
smsg.msg_controllen = CMSG_LEN(sizeof(struct ucred));;
smsg.msg_flags = 0;
cmsg = CMSG_FIRSTHDR(&smsg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_CREDENTIALS;
cmsg->cmsg_len = sizeof(cred_msg);
cred = (struct ucred *) CMSG_DATA(cmsg);
cred->uid = getuid();
cred->gid = getgid();
cred->pid = getpid();
cred->pid = getpid();
/* If we can't send, try to start daemon and resend message */
loop = UDEVSEND_CONNECT_RETRY;
while (loop--) {
retval = sendmsg(sock, &smsg, 0);
if (retval != -1) {
retval = 0;
goto close_and_exit;
}
if (errno != ECONNREFUSED) {
dbg("error sending message");
goto close_and_exit;
}
if (!started_daemon) {
dbg("connect failed, try starting daemon...");
retval = start_daemon();
if (retval) {
dbg("error starting daemon");
goto exit;
}
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);
}
}
close_and_exit:
close(sock);
exit:
return retval;
}
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