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/*
* Unix SMB/CIFS implementation.
* Samba system utilities
* Copyright (C) Jeremy Allison 2000
*
* 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; either version 3 of the License, or
* (at your option) any later version.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include "replace.h"
#include "system/wait.h"
#include "system/filesys.h"
#include <talloc.h>
#include "lib/util/sys_popen.h"
#include "lib/util/debug.h"
/**************************************************************************
Wrapper for popen. Safer as it doesn't search a path.
Modified from the glibc sources.
modified by tridge to return a file descriptor. We must kick our FILE* habit
****************************************************************************/
typedef struct _popen_list
{
int fd;
pid_t child_pid;
struct _popen_list *next;
} popen_list;
static popen_list *popen_chain;
int sys_popenv(char * const argl[])
{
int parent_end, child_end;
int pipe_fds[2];
popen_list *entry = NULL;
const char *command = NULL;
int ret;
if (argl == NULL) {
errno = EINVAL;
return -1;
}
command = argl[0];
if (!*command) {
errno = EINVAL;
return -1;
}
ret = pipe(pipe_fds);
if (ret < 0) {
DBG_ERR("error opening pipe: %s\n",
strerror(errno));
return -1;
}
parent_end = pipe_fds[0];
child_end = pipe_fds[1];
entry = talloc_zero(NULL, popen_list);
if (entry == NULL) {
DBG_ERR("talloc failed\n");
goto err_exit;
}
entry->child_pid = fork();
if (entry->child_pid == -1) {
DBG_ERR("fork failed: %s\n", strerror(errno));
goto err_exit;
}
if (entry->child_pid == 0) {
/*
* Child !
*/
int child_std_end = STDOUT_FILENO;
popen_list *p;
close(parent_end);
if (child_end != child_std_end) {
dup2 (child_end, child_std_end);
close (child_end);
}
/*
* POSIX.2: "popen() shall ensure that any streams from previous
* popen() calls that remain open in the parent process are closed
* in the new child process."
*/
for (p = popen_chain; p; p = p->next)
close(p->fd);
ret = execv(argl[0], argl);
if (ret == -1) {
DBG_ERR("ERROR executing command "
"'%s': %s\n", command, strerror(errno));
}
_exit (127);
}
/*
* Parent.
*/
close (child_end);
/* Link into popen_chain. */
entry->next = popen_chain;
popen_chain = entry;
entry->fd = parent_end;
return entry->fd;
err_exit:
TALLOC_FREE(entry);
close(pipe_fds[0]);
close(pipe_fds[1]);
return -1;
}
/**************************************************************************
Wrapper for pclose. Modified from the glibc sources.
****************************************************************************/
int sys_pclose(int fd)
{
int wstatus;
popen_list **ptr = &popen_chain;
popen_list *entry = NULL;
pid_t wait_pid;
int status = -1;
/* Unlink from popen_chain. */
for ( ; *ptr != NULL; ptr = &(*ptr)->next) {
if ((*ptr)->fd == fd) {
entry = *ptr;
*ptr = (*ptr)->next;
status = 0;
break;
}
}
if (status < 0 || close(entry->fd) < 0)
return -1;
/*
* As Samba is catching and eating child process
* exits we don't really care about the child exit
* code, a -1 with errno = ECHILD will do fine for us.
*/
do {
wait_pid = waitpid (entry->child_pid, &wstatus, 0);
} while (wait_pid == -1 && errno == EINTR);
TALLOC_FREE(entry);
if (wait_pid == -1)
return -1;
return wstatus;
}
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