busybox/loginutils/su.c

/* vi: set sw=4 ts=4: */
/*
 *  Mini su implementation for busybox
 *
 *  Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#include "busybox.h"
#include <syslog.h>

#define SU_OPT_mp (3)
#define SU_OPT_l (4)

int su_main(int argc, char **argv)
{
	unsigned flags;
	char *opt_shell = 0;
	char *opt_command = 0;
	char *opt_username = "root";
	struct passwd *pw;
	uid_t cur_uid = getuid();
	const char *tty;
	char *old_user;

	flags = getopt32(argc, argv, "mplc:s:", &opt_command, &opt_shell);
	argc -= optind;
	argv += optind;

	if (argc && LONE_DASH(argv[0])) {
		flags |= SU_OPT_l;
		argc--;
		argv++;
	}

	/* get user if specified */
	if (argc) {
		opt_username = argv[0];
//		argc--;
		argv++;
	}

	if (ENABLE_FEATURE_SU_SYSLOG) {
		/* The utmp entry (via getlogin) is probably the best way to identify
		the user, especially if someone su's from a su-shell.
		But getlogin can fail -- usually due to lack of utmp entry.
		in this case resort to getpwuid.  */
		old_user = xstrdup(USE_FEATURE_UTMP(getlogin() ? : ) (pw = getpwuid(cur_uid)) ? pw->pw_name : "");
		tty = ttyname(2) ? : "none";
		openlog(applet_name, 0, LOG_AUTH);
	}

	pw = getpwnam(opt_username);
	if (!pw)
		bb_error_msg_and_die("unknown id: %s", opt_username);

	/* Make sure pw->pw_shell is non-NULL.  It may be NULL when NEW_USER
	   is a username that is retrieved via NIS (YP), but that doesn't have
	   a default shell listed.  */
	if (!pw->pw_shell || !pw->pw_shell[0])
		pw->pw_shell = (char *)DEFAULT_SHELL;

	if ((cur_uid == 0) || correct_password(pw)) {
		if (ENABLE_FEATURE_SU_SYSLOG)
			syslog(LOG_NOTICE, "%c %s %s:%s",
				'+', tty, old_user, opt_username);
	} else {
		if (ENABLE_FEATURE_SU_SYSLOG)
			syslog(LOG_NOTICE, "%c %s %s:%s",
				'-', tty, old_user, opt_username);
		bb_error_msg_and_die("incorrect password");
	}

	if (ENABLE_FEATURE_CLEAN_UP && ENABLE_FEATURE_SU_SYSLOG) {
		closelog();
		free(old_user);
	}

	if (!opt_shell && (flags & SU_OPT_mp))
		opt_shell = getenv("SHELL");

#if ENABLE_FEATURE_SU_CHECKS_SHELLS
	if (opt_shell && cur_uid && restricted_shell(pw->pw_shell)) {
		/* The user being su'd to has a nonstandard shell, and so is
		   probably a uucp account or has restricted access.  Don't
		   compromise the account by allowing access with a standard
		   shell.  */
		bb_error_msg("using restricted shell");
		opt_shell = 0;
	}
#endif
	if (!opt_shell)
		opt_shell = pw->pw_shell;

	change_identity(pw);
	setup_environment(opt_shell, flags & SU_OPT_l, !(flags & SU_OPT_mp), pw);
	USE_SELINUX(set_current_security_context(NULL);)

	/* Never returns */
	run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)argv);

	return EXIT_FAILURE;
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Mini su implementation for busybox
4	*
5	* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
6	*/
7
8	#include "busybox.h"
9	#include <syslog.h>
10
11	#define SU_OPT_mp (3)
12	#define SU_OPT_l (4)
13
14	int su_main(int argc, char **argv)
15	{
16	unsigned flags;
17	char *opt_shell = 0;
18	char *opt_command = 0;
19	char *opt_username = "root";
20	struct passwd *pw;
21	uid_t cur_uid = getuid();
22	const char *tty;
23	char *old_user;
24
25	flags = getopt32(argc, argv, "mplc:s:", &opt_command, &opt_shell);
26	argc -= optind;
27	argv += optind;
28
29	if (argc && LONE_DASH(argv[0])) {
30	flags \|= SU_OPT_l;
31	argc--;
32	argv++;
33	}
34
35	/* get user if specified */
36	if (argc) {
37	opt_username = argv[0];
38	// argc--;
39	argv++;
40	}
41
42	if (ENABLE_FEATURE_SU_SYSLOG) {
43	/* The utmp entry (via getlogin) is probably the best way to identify
44	the user, especially if someone su's from a su-shell.
45	But getlogin can fail -- usually due to lack of utmp entry.
46	in this case resort to getpwuid. */
47	old_user = xstrdup(USE_FEATURE_UTMP(getlogin() ? : ) (pw = getpwuid(cur_uid)) ? pw->pw_name : "");
48	tty = ttyname(2) ? : "none";
49	openlog(applet_name, 0, LOG_AUTH);
50	}
51
52	pw = getpwnam(opt_username);
53	if (!pw)
54	bb_error_msg_and_die("unknown id: %s", opt_username);
55
56	/* Make sure pw->pw_shell is non-NULL. It may be NULL when NEW_USER
57	is a username that is retrieved via NIS (YP), but that doesn't have
58	a default shell listed. */
59	if (!pw->pw_shell \|\| !pw->pw_shell[0])
60	pw->pw_shell = (char *)DEFAULT_SHELL;
61
62	if ((cur_uid == 0) \|\| correct_password(pw)) {
63	if (ENABLE_FEATURE_SU_SYSLOG)
64	syslog(LOG_NOTICE, "%c %s %s:%s",
65	'+', tty, old_user, opt_username);
66	} else {
67	if (ENABLE_FEATURE_SU_SYSLOG)
68	syslog(LOG_NOTICE, "%c %s %s:%s",
69	'-', tty, old_user, opt_username);
70	bb_error_msg_and_die("incorrect password");
71	}
72
73	if (ENABLE_FEATURE_CLEAN_UP && ENABLE_FEATURE_SU_SYSLOG) {
74	closelog();
75	free(old_user);
76	}
77
78	if (!opt_shell && (flags & SU_OPT_mp))
79	opt_shell = getenv("SHELL");
80
81	#if ENABLE_FEATURE_SU_CHECKS_SHELLS
82	if (opt_shell && cur_uid && restricted_shell(pw->pw_shell)) {
83	/* The user being su'd to has a nonstandard shell, and so is
84	probably a uucp account or has restricted access. Don't
85	compromise the account by allowing access with a standard
86	shell. */
87	bb_error_msg("using restricted shell");
88	opt_shell = 0;
89	}
90	#endif
91	if (!opt_shell)
92	opt_shell = pw->pw_shell;
93
94	change_identity(pw);
95	setup_environment(opt_shell, flags & SU_OPT_l, !(flags & SU_OPT_mp), pw);
96	USE_SELINUX(set_current_security_context(NULL);)
97
98	/* Never returns */
99	run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)argv);
100
101	return EXIT_FAILURE;
102	}