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/*
* dhcpcd - DHCP client daemon
* Copyright (c) 2006-2012 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.
*/
/* This implementation of posix_spawn is only suitable for the needs of dhcpcd
* but it could easily be extended to other applications. */
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "../common.h"
#include "posix_spawn.h"
#ifndef _NSIG
#ifdef _SIG_MAXSIG
#define _NSIG _SIG_MAXSIG + 1
#else
/* Guess */
#define _NSIG SIGPWR + 1
#endif
#endif
extern char **environ;
static int
posix_spawnattr_handle(const posix_spawnattr_t *attrp)
{
struct sigaction sa;
int i;
if (attrp->posix_attr_flags & POSIX_SPAWN_SETSIGMASK)
sigprocmask(SIG_SETMASK, &attrp->posix_attr_sigmask, NULL);
if (attrp->posix_attr_flags & POSIX_SPAWN_SETSIGDEF) {
memset(&sa, 0, sizeof(sa));
sa.sa_handler = SIG_DFL;
for (i = 1; i < _NSIG; i++) {
if (sigismember(&attrp->posix_attr_sigdefault, i)) {
if (sigaction(i, &sa, NULL) == -1)
return -1;
}
}
}
return 0;
}
int
posix_spawn(pid_t *pid, const char * path,
__unused void *arg,
const posix_spawnattr_t *attrp,
char *const argv[], char *const envp[])
{
pid_t p;
volatile int error;
error = 0;
#ifdef THERE_IS_NO_FORK
/* Pray we can sanely modify signal foo */
p = vfork();
#else
p = fork();
#endif
switch (p) {
case -1:
return errno;
case 0:
if (attrp) {
error = posix_spawnattr_handle(attrp);
if (error)
_exit(127);
}
execve(path, argv, envp);
error = errno;
_exit(127);
default:
if (error != 0)
waitpid(p, NULL, WNOHANG);
else if (pid != NULL)
*pid = p;
return error;
}
}
int
posix_spawnattr_init(posix_spawnattr_t *attr)
{
memset(attr, 0, sizeof(*attr));
attr->posix_attr_flags = 0;
sigprocmask(0, NULL, &attr->posix_attr_sigmask);
sigemptyset(&attr->posix_attr_sigdefault);
return 0;
}
int
posix_spawnattr_setflags(posix_spawnattr_t *attr, short flags)
{
attr->posix_attr_flags = flags;
return 0;
}
int
posix_spawnattr_setsigmask(posix_spawnattr_t *attr, const sigset_t *sigmask)
{
attr->posix_attr_sigmask = *sigmask;
return 0;
}
int
posix_spawnattr_setsigdefault(posix_spawnattr_t *attr, const sigset_t *sigmask)
{
attr->posix_attr_sigdefault = *sigmask;
return 0;
}
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