1 /* vi: set sw=4 ts=4: */
2 /*
3  * Copyright 1989 - 1991, Julianne Frances Haugh <jockgrrl@austin.rr.com>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of Julianne F. Haugh nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include "libbb.h"
32 #if ENABLE_SELINUX
33 #include <selinux/selinux.h>  /* for setexeccon  */
34 #endif
35 
36 #if ENABLE_SELINUX
37 static security_context_t current_sid;
38 
renew_current_security_context(void)39 void FAST_FUNC renew_current_security_context(void)
40 {
41 	freecon(current_sid);  /* Release old context  */
42 	getcon(&current_sid);  /* update */
43 }
set_current_security_context(security_context_t sid)44 void FAST_FUNC set_current_security_context(security_context_t sid)
45 {
46 	freecon(current_sid);  /* Release old context  */
47 	current_sid = sid;
48 }
49 
50 #endif
51 
52 /* Run SHELL, or DEFAULT_SHELL if SHELL is "" or NULL.
53  * If ADDITIONAL_ARGS is not NULL, pass them to the shell.
54  */
run_shell(const char * shell,int loginshell,const char ** additional_args)55 void FAST_FUNC run_shell(const char *shell, int loginshell, const char **additional_args)
56 {
57 	const char **args;
58 
59 	args = additional_args;
60 	while (args && *args)
61 		args++;
62 
63 	args = xmalloc(sizeof(char*) * (2 + (args - additional_args)));
64 
65 	if (!shell || !shell[0])
66 		shell = DEFAULT_SHELL;
67 
68 	args[0] = bb_get_last_path_component_nostrip(shell);
69 	if (loginshell)
70 		args[0] = xasprintf("-%s", args[0]);
71 	args[1] = NULL;
72 	if (additional_args) {
73 		int cnt = 1;
74 		for (;;)
75 			if ((args[cnt++] = *additional_args++) == NULL)
76 				break;
77 	}
78 
79 #if ENABLE_SELINUX
80 	if (current_sid)
81 		setexeccon(current_sid);
82 	if (ENABLE_FEATURE_CLEAN_UP)
83 		freecon(current_sid);
84 #endif
85 	execv(shell, (char **) args);
86 	bb_perror_msg_and_die("can't execute '%s'", shell);
87 }
88