mirror of
https://github.com/rsmarples/dhcpcd.git
synced 2024-11-28 12:33:49 +08:00
125 lines
3.1 KiB
C
125 lines
3.1 KiB
C
/*
|
|
* dhcpcd - DHCP client daemon
|
|
* Copyright (c) 2006-2009 Roy Marples <roy@marples.name>
|
|
* All rights reserved
|
|
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/socket.h>
|
|
|
|
#include <errno.h>
|
|
#include <signal.h>
|
|
#include <string.h>
|
|
#include <syslog.h>
|
|
#include <unistd.h>
|
|
|
|
#include "common.h"
|
|
#include "signals.h"
|
|
|
|
static int signal_pipe[2];
|
|
|
|
static const int handle_sigs[] = {
|
|
SIGALRM,
|
|
SIGHUP,
|
|
SIGINT,
|
|
SIGPIPE,
|
|
SIGTERM,
|
|
SIGUSR1,
|
|
};
|
|
|
|
static void
|
|
signal_handler(int sig)
|
|
{
|
|
int serrno = errno;
|
|
|
|
if (write(signal_pipe[1], &sig, sizeof(sig)) != sizeof(sig))
|
|
syslog(LOG_ERR, "failed to write signal %d: %m", sig);
|
|
/* Restore errno */
|
|
errno = serrno;
|
|
}
|
|
|
|
/* Read a signal from the signal pipe. Returns 0 if there is
|
|
* no signal, -1 on error (and sets errno appropriately), and
|
|
* your signal on success */
|
|
int
|
|
signal_read(void)
|
|
{
|
|
int sig = -1;
|
|
char buf[16];
|
|
ssize_t bytes;
|
|
|
|
memset(buf, 0, sizeof(buf));
|
|
bytes = read(signal_pipe[0], buf, sizeof(buf));
|
|
if (bytes >= 0 && (size_t)bytes >= sizeof(sig))
|
|
memcpy(&sig, buf, sizeof(sig));
|
|
return sig;
|
|
}
|
|
|
|
/* Call this before doing anything else. Sets up the socket pair
|
|
* and installs the signal handler */
|
|
int
|
|
signal_init(void)
|
|
{
|
|
if (pipe(signal_pipe) == -1)
|
|
return -1;
|
|
/* Don't block on read */
|
|
if (set_nonblock(signal_pipe[0]) == -1)
|
|
return -1;
|
|
/* Stop any scripts from inheriting us */
|
|
if (set_cloexec(signal_pipe[0]) == -1)
|
|
return -1;
|
|
if (set_cloexec(signal_pipe[1]) == -1)
|
|
return -1;
|
|
return signal_pipe[0];
|
|
}
|
|
|
|
static int
|
|
signal_handle(void (*func)(int))
|
|
{
|
|
unsigned int i;
|
|
struct sigaction sa;
|
|
|
|
memset(&sa, 0, sizeof(sa));
|
|
sa.sa_handler = func;
|
|
sigemptyset(&sa.sa_mask);
|
|
|
|
for (i = 0; i < sizeof(handle_sigs) / sizeof(handle_sigs[0]); i++)
|
|
if (sigaction(handle_sigs[i], &sa, NULL) == -1)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
signal_setup(void)
|
|
{
|
|
return signal_handle(signal_handler);
|
|
}
|
|
|
|
int
|
|
signal_reset(void)
|
|
{
|
|
return signal_handle(SIG_DFL);
|
|
}
|
|
|