busybox/loginutils/su.c
Denis Vlasenko 62a90cdd74 *: shrink by using [f]open_or_warn_stdin where appropriate
function                                             old     new   delta
lsattr_main                                           62     143     +81
open_or_warn_stdin                                     -      36     +36
fclose_if_not_stdin                                   20      47     +27
xfopen_stdin                                           -      20     +20
tac_main                                             336     356     +20
cksum_main                                           249     259     +10
bb_argv_dash                                           -       8      +8
su_main                                              448     455      +7
cmp_main                                             630     633      +3
passwd_main                                         1072    1074      +2
uudecode_main                                        317     315      -2
text_yank                                            110     108      -2
handle_incoming_and_exit                            2653    2651      -2
flags                                                  5       1      -4
write_leases                                         235     230      -5
fopen_or_warn_stdin                                   48      42      -6
fold_main                                            648     642      -6
static.argv_dash                                       8       -      -8
sum_main                                             142     128     -14
tail_main                                           1237    1221     -16
sed_main                                             711     695     -16
cmp_xfopen_input                                      17       -     -17
bb_cat                                               113      96     -17
catv_main                                            328     306     -22
strings_main                                         457     434     -23
hash_file                                            298     274     -24
sum_file                                             353     325     -28
sort_main                                            904     859     -45
expand_main                                          736     686     -50
cut_main                                            1116    1065     -51
md5_sha1_sum_main                                    549     493     -56
lsattr_args                                           90       -     -90
read_stduu                                           408     255    -153
------------------------------------------------------------------------------
(add/remove: 3/3 grow/shrink: 7/20 up/down: 214/-657)        Total: -443 bytes
   text    data     bss     dec     hex filename
 797417     658    7428  805503   c4a7f busybox_old
 796973     658    7428  805059   c48c3 busybox_unstripped
2008-03-17 09:07:36 +00:00

103 lines
2.8 KiB
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 "libbb.h"
#include <syslog.h>
#define SU_OPT_mp (3)
#define SU_OPT_l (4)
int su_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int su_main(int argc ATTRIBUTE_UNUSED, char **argv)
{
unsigned flags;
char *opt_shell = NULL;
char *opt_command = NULL;
const char *opt_username = "root";
struct passwd *pw;
uid_t cur_uid = getuid();
const char *tty;
char *old_user;
flags = getopt32(argv, "mplc:s:", &opt_command, &opt_shell);
//argc -= optind;
argv += optind;
if (argv[0] && LONE_DASH(argv[0])) {
flags |= SU_OPT_l;
argv++;
}
/* get user if specified */
if (argv[0]) {
opt_username = argv[0];
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 = NULL;
}
#endif
if (!opt_shell)
opt_shell = pw->pw_shell;
change_identity(pw);
/* setup_environment params: shell, clear_env, change_env, 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; - not reached */
}