dhcpcd/signals.c
Roy Marples fd05b7dcfc Add an event loop.
Split client.c into smaller files and functions and
recode around the event loop.
Add multiple interface support using the new event loop.
Document changes and outstanding bugs.
2008-09-02 13:28:11 +00:00

121 lines
3.0 KiB
C

/*
* dhcpcd - DHCP client daemon
* Copyright 2006-2008 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 <unistd.h>
#include "common.h"
#include "signals.h"
static int signal_pipe[2];
static const int handle_sigs[] = {
SIGHUP,
SIGALRM,
SIGTERM,
SIGINT
};
static void
signal_handler(int sig)
{
int serrno = errno;
write(signal_pipe[1], &sig, sizeof(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];
size_t bytes;
memset(buf, 0, sizeof(buf));
bytes = read(signal_pipe[0], buf, sizeof(buf));
if (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);
}