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|
/* $OpenBSD: posix_spawn.c,v 1.2 2012/03/22 15:43:08 deraadt Exp $ */
/*-
* Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
* 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/cdefs.h>
#include "namespace.h"
#include <sys/queue.h>
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <spawn.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
extern char **environ;
struct __posix_spawnattr {
short sa_flags;
pid_t sa_pgroup;
struct sched_param sa_schedparam;
int sa_schedpolicy;
sigset_t sa_sigdefault;
sigset_t sa_sigmask;
};
struct __posix_spawn_file_actions {
SIMPLEQ_HEAD(, __posix_spawn_file_actions_entry) fa_list;
};
typedef struct __posix_spawn_file_actions_entry {
SIMPLEQ_ENTRY(__posix_spawn_file_actions_entry) fae_list;
enum { FAE_OPEN, FAE_DUP2, FAE_CLOSE } fae_action;
int fae_fildes;
union {
struct {
char *path;
#define fae_path fae_data.open.path
int oflag;
#define fae_oflag fae_data.open.oflag
mode_t mode;
#define fae_mode fae_data.open.mode
} open;
struct {
int newfildes;
#define fae_newfildes fae_data.dup2.newfildes
} dup2;
} fae_data;
} posix_spawn_file_actions_entry_t;
/*
* Spawn routines
*/
static int
process_spawnattr(const posix_spawnattr_t sa)
{
struct sigaction sigact;
int i;
memset(&sigact, 0, sizeof(sigact));
sigact.sa_handler = SIG_DFL;
/*
* POSIX doesn't really describe in which order everything
* should be set. We'll just set them in the order in which they
* are mentioned.
*/
/* Set process group */
if (sa->sa_flags & POSIX_SPAWN_SETPGROUP) {
if (setpgid(0, sa->sa_pgroup) != 0)
return (errno);
}
#if 0 /* NOT IMPLEMENTED */
/* Set scheduler policy */
if (sa->sa_flags & POSIX_SPAWN_SETSCHEDULER) {
if (sched_setscheduler(0, sa->sa_schedpolicy,
&sa->sa_schedparam) != 0)
return (errno);
} else if (sa->sa_flags & POSIX_SPAWN_SETSCHEDPARAM) {
if (sched_setparam(0, &sa->sa_schedparam) != 0)
return (errno);
}
#endif
/* Reset user ID's */
if (sa->sa_flags & POSIX_SPAWN_RESETIDS) {
if (setegid(getgid()) != 0)
return (errno);
if (seteuid(getuid()) != 0)
return (errno);
}
/* Set signal masks/defaults */
if (sa->sa_flags & POSIX_SPAWN_SETSIGMASK) {
sigprocmask(SIG_SETMASK, &sa->sa_sigmask, NULL);
}
if (sa->sa_flags & POSIX_SPAWN_SETSIGDEF) {
for (i = 1; i <= _NSIG; i++) {
if (sigismember(&sa->sa_sigdefault, i))
if (sigaction(i, &sigact, NULL) != 0)
return (errno);
}
}
return (0);
}
static int
process_file_actions_entry(posix_spawn_file_actions_entry_t *fae)
{
int fd;
switch (fae->fae_action) {
case FAE_OPEN:
/* Perform an open(), make it use the right fd */
fd = open(fae->fae_path, fae->fae_oflag, fae->fae_mode);
if (fd < 0)
return (errno);
if (fd != fae->fae_fildes) {
if (dup2(fd, fae->fae_fildes) == -1)
return (errno);
if (close(fd) != 0) {
if (errno == EBADF)
return (EBADF);
}
}
break;
case FAE_DUP2:
/* Perform a dup2() */
if (dup2(fae->fae_fildes, fae->fae_newfildes) == -1)
return (errno);
break;
case FAE_CLOSE:
/* Perform a close(), do not fail if already closed */
(void)close(fae->fae_fildes);
break;
}
return (0);
}
static int
process_file_actions(const posix_spawn_file_actions_t fa)
{
posix_spawn_file_actions_entry_t *fae;
int error;
/* Replay all file descriptor modifications */
SIMPLEQ_FOREACH(fae, &fa->fa_list, fae_list) {
error = process_file_actions_entry(fae);
if (error)
return (error);
}
return (0);
}
static int
do_posix_spawn(pid_t *pid, const char *path,
const posix_spawn_file_actions_t *fa,
const posix_spawnattr_t *sa,
char *const argv[], char *const envp[], int use_env_path)
{
pid_t p;
p = fork();
switch (p) {
case -1:
return (errno);
case 0: {
int error;
if (sa != NULL) {
error = process_spawnattr(*sa);
if (error)
_exit(127);
}
if (fa != NULL) {
error = process_file_actions(*fa);
if (error)
_exit(127);
}
if (use_env_path)
execvpe(path, argv, envp != NULL ? envp : environ);
else
execve(path, argv, envp != NULL ? envp : environ);
_exit(127);
}
default:
if (pid != NULL)
*pid = p;
return (0);
}
}
int
posix_spawn(pid_t *pid, const char *path,
const posix_spawn_file_actions_t *fa,
const posix_spawnattr_t *sa,
char *const argv[], char *const envp[])
{
return do_posix_spawn(pid, path, fa, sa, argv, envp, 0);
}
int
posix_spawnp(pid_t *pid, const char *path,
const posix_spawn_file_actions_t *fa,
const posix_spawnattr_t *sa,
char *const argv[], char *const envp[])
{
return do_posix_spawn(pid, path, fa, sa, argv, envp, 1);
}
/*
* File descriptor actions
*/
int
posix_spawn_file_actions_init(posix_spawn_file_actions_t *ret)
{
posix_spawn_file_actions_t fa;
fa = malloc(sizeof(struct __posix_spawn_file_actions));
if (fa == NULL)
return (errno);
SIMPLEQ_INIT(&fa->fa_list);
*ret = fa;
return (0);
}
int
posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *fa)
{
posix_spawn_file_actions_entry_t *fae;
while ((fae = SIMPLEQ_FIRST(&(*fa)->fa_list)) != NULL) {
/* Remove file action entry from the queue */
SIMPLEQ_REMOVE_HEAD(&(*fa)->fa_list, fae_list);
/* Deallocate file action entry */
if (fae->fae_action == FAE_OPEN)
free(fae->fae_path);
free(fae);
}
free(*fa);
return (0);
}
int
posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *__restrict fa,
int fildes, const char *__restrict path, int oflag, mode_t mode)
{
posix_spawn_file_actions_entry_t *fae;
int error;
if (fildes < 0)
return (EBADF);
/* Allocate object */
fae = malloc(sizeof(posix_spawn_file_actions_entry_t));
if (fae == NULL)
return (errno);
/* Set values and store in queue */
fae->fae_action = FAE_OPEN;
fae->fae_path = strdup(path);
if (fae->fae_path == NULL) {
error = errno;
free(fae);
return (error);
}
fae->fae_fildes = fildes;
fae->fae_oflag = oflag;
fae->fae_mode = mode;
SIMPLEQ_INSERT_TAIL(&(*fa)->fa_list, fae, fae_list);
return (0);
}
int
posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *fa,
int fildes, int newfildes)
{
posix_spawn_file_actions_entry_t *fae;
if (fildes < 0 || newfildes < 0)
return (EBADF);
/* Allocate object */
fae = malloc(sizeof(posix_spawn_file_actions_entry_t));
if (fae == NULL)
return (errno);
/* Set values and store in queue */
fae->fae_action = FAE_DUP2;
fae->fae_fildes = fildes;
fae->fae_newfildes = newfildes;
SIMPLEQ_INSERT_TAIL(&(*fa)->fa_list, fae, fae_list);
return (0);
}
int
posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *fa,
int fildes)
{
posix_spawn_file_actions_entry_t *fae;
if (fildes < 0)
return (EBADF);
/* Allocate object */
fae = malloc(sizeof(posix_spawn_file_actions_entry_t));
if (fae == NULL)
return (errno);
/* Set values and store in queue */
fae->fae_action = FAE_CLOSE;
fae->fae_fildes = fildes;
SIMPLEQ_INSERT_TAIL(&(*fa)->fa_list, fae, fae_list);
return (0);
}
/*
* Spawn attributes
*/
int
posix_spawnattr_init(posix_spawnattr_t *ret)
{
posix_spawnattr_t sa;
sa = calloc(1, sizeof(struct __posix_spawnattr));
if (sa == NULL)
return (errno);
/* Set defaults as specified by POSIX, cleared above */
*ret = sa;
return (0);
}
int
posix_spawnattr_destroy(posix_spawnattr_t *sa)
{
free(*sa);
return (0);
}
int
posix_spawnattr_getflags(const posix_spawnattr_t *__restrict sa,
short *__restrict flags)
{
*flags = (*sa)->sa_flags;
return (0);
}
int
posix_spawnattr_getpgroup(const posix_spawnattr_t *__restrict sa,
pid_t *__restrict pgroup)
{
*pgroup = (*sa)->sa_pgroup;
return (0);
}
int
posix_spawnattr_getschedparam(const posix_spawnattr_t *__restrict sa,
struct sched_param *__restrict schedparam)
{
*schedparam = (*sa)->sa_schedparam;
return (0);
}
int
posix_spawnattr_getschedpolicy(const posix_spawnattr_t *__restrict sa,
int *__restrict schedpolicy)
{
*schedpolicy = (*sa)->sa_schedpolicy;
return (0);
}
int
posix_spawnattr_getsigdefault(const posix_spawnattr_t *__restrict sa,
sigset_t *__restrict sigdefault)
{
*sigdefault = (*sa)->sa_sigdefault;
return (0);
}
int
posix_spawnattr_getsigmask(const posix_spawnattr_t *__restrict sa,
sigset_t *__restrict sigmask)
{
*sigmask = (*sa)->sa_sigmask;
return (0);
}
int
posix_spawnattr_setflags(posix_spawnattr_t *sa, short flags)
{
(*sa)->sa_flags = flags;
return (0);
}
int
posix_spawnattr_setpgroup(posix_spawnattr_t *sa, pid_t pgroup)
{
(*sa)->sa_pgroup = pgroup;
return (0);
}
int
posix_spawnattr_setschedparam(posix_spawnattr_t *__restrict sa,
const struct sched_param *__restrict schedparam)
{
(*sa)->sa_schedparam = *schedparam;
return (0);
}
int
posix_spawnattr_setschedpolicy(posix_spawnattr_t *sa, int schedpolicy)
{
(*sa)->sa_schedpolicy = schedpolicy;
return (0);
}
int
posix_spawnattr_setsigdefault(posix_spawnattr_t *__restrict sa,
const sigset_t *__restrict sigdefault)
{
(*sa)->sa_sigdefault = *sigdefault;
return (0);
}
int
posix_spawnattr_setsigmask(posix_spawnattr_t *__restrict sa,
const sigset_t *__restrict sigmask)
{
(*sa)->sa_sigmask = *sigmask;
return (0);
}
|