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    Annotation of /trunk/mkinitrd-magellan/busybox/loginutils/su.c

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    Revision 984 - (hide annotations) (download)
    Sun May 30 11:32:42 2010 UTC (14 years ago) by niro
    File MIME type: text/plain
    File size: 2957 byte(s) 
    -updated to busybox-1.16.1 and enabled blkid/uuid support in default config
    1 niro 532 /* 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 niro 816 #include "libbb.h"
    9 niro 532 #include <syslog.h>
    10    
    11     #define SU_OPT_mp (3)
    12     #define SU_OPT_l (4)
    13    
    14 niro 816 int su_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
    15     int su_main(int argc UNUSED_PARAM, char **argv)
    16 niro 532 {
    17     unsigned flags;
    18 niro 816 char *opt_shell = NULL;
    19     char *opt_command = NULL;
    20     const char *opt_username = "root";
    21 niro 532 struct passwd *pw;
    22     uid_t cur_uid = getuid();
    23     const char *tty;
    24     char *old_user;
    25    
    26 niro 816 flags = getopt32(argv, "mplc:s:", &opt_command, &opt_shell);
    27     //argc -= optind;
    28 niro 532 argv += optind;
    29    
    30 niro 816 if (argv[0] && LONE_DASH(argv[0])) {
    31 niro 532 flags |= SU_OPT_l;
    32     argv++;
    33     }
    34    
    35     /* get user if specified */
    36 niro 816 if (argv[0]) {
    37 niro 532 opt_username = argv[0];
    38     argv++;
    39     }
    40    
    41     if (ENABLE_FEATURE_SU_SYSLOG) {
    42     /* The utmp entry (via getlogin) is probably the best way to identify
    43 niro 984 * the user, especially if someone su's from a su-shell.
    44     * But getlogin can fail -- usually due to lack of utmp entry.
    45     * in this case resort to getpwuid. */
    46     const char *user;
    47     #if ENABLE_FEATURE_UTMP
    48     char user_buf[64];
    49     user = user_buf;
    50     if (getlogin_r(user_buf, sizeof(user_buf)) != 0)
    51     #endif
    52     {
    53     pw = getpwuid(cur_uid);
    54     user = pw ? pw->pw_name : "";
    55     }
    56     old_user = xstrdup(user);
    57     tty = xmalloc_ttyname(2);
    58     if (!tty) {
    59     tty = "none";
    60     }
    61 niro 532 openlog(applet_name, 0, LOG_AUTH);
    62     }
    63    
    64 niro 984 pw = xgetpwnam(opt_username);
    65 niro 532
    66     /* Make sure pw->pw_shell is non-NULL. It may be NULL when NEW_USER
    67     is a username that is retrieved via NIS (YP), but that doesn't have
    68     a default shell listed. */
    69     if (!pw->pw_shell || !pw->pw_shell[0])
    70     pw->pw_shell = (char *)DEFAULT_SHELL;
    71    
    72     if ((cur_uid == 0) || correct_password(pw)) {
    73     if (ENABLE_FEATURE_SU_SYSLOG)
    74     syslog(LOG_NOTICE, "%c %s %s:%s",
    75     '+', tty, old_user, opt_username);
    76     } else {
    77     if (ENABLE_FEATURE_SU_SYSLOG)
    78     syslog(LOG_NOTICE, "%c %s %s:%s",
    79     '-', tty, old_user, opt_username);
    80     bb_error_msg_and_die("incorrect password");
    81     }
    82    
    83     if (ENABLE_FEATURE_CLEAN_UP && ENABLE_FEATURE_SU_SYSLOG) {
    84     closelog();
    85     free(old_user);
    86     }
    87    
    88     if (!opt_shell && (flags & SU_OPT_mp))
    89     opt_shell = getenv("SHELL");
    90    
    91     #if ENABLE_FEATURE_SU_CHECKS_SHELLS
    92     if (opt_shell && cur_uid && restricted_shell(pw->pw_shell)) {
    93     /* The user being su'd to has a nonstandard shell, and so is
    94     probably a uucp account or has restricted access. Don't
    95     compromise the account by allowing access with a standard
    96     shell. */
    97     bb_error_msg("using restricted shell");
    98 niro 816 opt_shell = NULL;
    99 niro 532 }
    100     #endif
    101     if (!opt_shell)
    102     opt_shell = pw->pw_shell;
    103    
    104     change_identity(pw);
    105 niro 816 /* setup_environment params: shell, clear_env, change_env, pw */
    106 niro 532 setup_environment(opt_shell, flags & SU_OPT_l, !(flags & SU_OPT_mp), pw);
    107 niro 984 IF_SELINUX(set_current_security_context(NULL);)
    108 niro 532
    109     /* Never returns */
    110     run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)argv);
    111    
    112 niro 816 /* return EXIT_FAILURE; - not reached */
    113 niro 532 }