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/*
* execve.c
*
* execve() wrapper.
*
* Copyright 1999-2006 Gentoo Foundation
*
*
* 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 version 2 of the License.
*
* 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, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Partly Copyright (C) 1998-9 Pancrazio `Ezio' de Mauro <p@demauro.net>,
* as some of the InstallWatch code was used.
*
* $Header$
*/
extern int EXTERN_NAME(const char *, char *const[], char *const[]);
static int (*WRAPPER_TRUE_NAME) (const char *, char *const[], char *const[]) = NULL;
int WRAPPER_NAME(const char *filename, char *const argv[], char *const envp[])
{
char **my_env = NULL;
char *entry;
char *ld_preload = NULL;
char *old_ld_preload = NULL;
int old_errno = errno;
int result = -1;
int count;
if (!FUNCTION_SANDBOX_SAFE("execve", filename))
return result;
str_list_for_each_item(envp, entry, count) {
if (strstr(entry, LD_PRELOAD_EQ) != entry)
continue;
/* Check if we do not have to do anything */
if (NULL != strstr(entry, sandbox_lib)) {
/* Use the user's envp */
my_env = (char **)envp;
goto do_execve;
} else {
old_ld_preload = entry;
/* No need to continue, we have to modify LD_PRELOAD */
break;
}
}
/* Ok, we need to create our own envp, as we need to add LD_PRELOAD,
* and we should not touch the user's envp. First we add LD_PRELOAD,
* and just all the rest. */
count = strlen(LD_PRELOAD_EQ) + strlen(sandbox_lib) + 1;
if (NULL != old_ld_preload)
count += strlen(old_ld_preload) - strlen(LD_PRELOAD_EQ) + 1;
ld_preload = xmalloc(count * sizeof(char));
if (NULL == ld_preload)
goto error;
snprintf(ld_preload, count, "%s%s%s%s", LD_PRELOAD_EQ, sandbox_lib,
(old_ld_preload) ? " " : "",
(old_ld_preload) ? old_ld_preload + strlen(LD_PRELOAD_EQ) : "");
str_list_add_item(my_env, ld_preload, error);
str_list_for_each_item(envp, entry, count) {
if (strstr(entry, LD_PRELOAD_EQ) != entry) {
str_list_add_item(my_env, entry, error);
continue;
}
}
do_execve:
errno = old_errno;
check_dlsym(WRAPPER_TRUE_NAME, WRAPPER_SYMNAME,
WRAPPER_SYMVER);
result = WRAPPER_TRUE_NAME(filename, argv, my_env);
if ((NULL != my_env) && (my_env != envp))
/* We do not use str_list_free(), as we did not allocate the
* entries except for LD_PRELOAD. */
free(my_env);
if (NULL != ld_preload)
free(ld_preload);
return result;
error:
if ((NULL != my_env) && (my_env != envp))
/* We do not use str_list_free(), as we did not allocate the
* entries except for LD_PRELOAD. */
free(my_env);
if (NULL != ld_preload)
free(ld_preload);
return -1;
}
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