diff options
Diffstat (limited to 'lib/util/sys_popen.c')
| -rw-r--r-- | lib/util/sys_popen.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/lib/util/sys_popen.c b/lib/util/sys_popen.c new file mode 100644 index 0000000..f62199b --- /dev/null +++ b/lib/util/sys_popen.c @@ -0,0 +1,177 @@ +/* + * 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; +} |