userapps/opensource/busybox/loginutils/sulogin.c

   1 /* vi: set sw=4 ts=4: */
   2 #include <fcntl.h>
   3 #include <signal.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <syslog.h>
   8 #include <unistd.h>
   9 #include <utmp.h>
  10 #include <sys/resource.h>
  11 #include <sys/stat.h>
  12 #include <sys/time.h>
  13 #include <sys/types.h>
  14 #include <ctype.h>
  15 #include <time.h>
  16
  17 #include "busybox.h"
  18
  19
  20 // sulogin defines
  21 #define SULOGIN_PROMPT "\nGive root password for system maintenance\n" \
  22         "(or type Control-D for normal startup):"
  23
  24 static const char *forbid[] = {
  25         "ENV",
  26         "BASH_ENV",
  27         "HOME",
  28         "IFS",
  29         "PATH",
  30         "SHELL",
  31         "LD_LIBRARY_PATH",
  32         "LD_PRELOAD",
  33         "LD_TRACE_LOADED_OBJECTS",
  34         "LD_BIND_NOW",
  35         "LD_AOUT_LIBRARY_PATH",
  36         "LD_AOUT_PRELOAD",
  37         "LD_NOWARN",
  38         "LD_KEEPDIR",
  39         (char *) 0
  40 };
  41
  42
  43
  44 static void catchalarm(int junk)
  45 {
  46         exit(EXIT_FAILURE);
  47 }
  48
  49
  50 extern int sulogin_main(int argc, char **argv)
  51 {
  52         char *cp;
  53         char *device = (char *) 0;
  54         const char *name = "root";
  55         int timeout = 0;
  56         static char pass[BUFSIZ];
  57         struct passwd pwent;
  58         struct passwd *pwd;
  59         time_t start, now;
  60         const char **p;
  61 #ifdef CONFIG_FEATURE_SHADOWPASSWDS
  62         struct spwd *spwd = NULL;
  63 #endif                                                  /* CONFIG_FEATURE_SHADOWPASSWDS */
  64
  65         openlog("sulogin", LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH);
  66         if (argc > 1) {
  67                 if (strncmp(argv[1], "-t", 2) == 0) {
  68                         if (strcmp(argv[1], "-t") == 0) {
  69                                 if (argc > 2) {
  70                                         timeout = atoi(argv[2]);
  71                                         if (argc > 3) {
  72                                                 device = argv[3];
  73                                         }
  74                                 }
  75                         } else {
  76                                 if (argc > 2) {
  77                                         device = argv[2];
  78                                 }
  79                         }
  80                 } else {
  81                         device = argv[1];
  82                 }
  83                 if (device) {
  84                         close(0);
  85                         close(1);
  86                         close(2);
  87                         if (open(device, O_RDWR) >= 0) {
  88                                 dup(0);
  89                                 dup(0);
  90                         } else {
  91                                 syslog(LOG_WARNING, "cannot open %s\n", device);
  92                                 exit(EXIT_FAILURE);
  93                         }
  94                 }
  95         }
  96         if (access(bb_path_passwd_file, 0) == -1) {
  97                 syslog(LOG_WARNING, "No password file\n");
  98                 bb_error_msg_and_die("No password file\n");
  99         }
 100         if (!isatty(0) || !isatty(1) || !isatty(2)) {
 101                 exit(EXIT_FAILURE);
 102         }
 103
 104
 105         /* Clear out anything dangerous from the environment */
 106         for (p = forbid; *p; p++)
 107                 unsetenv(*p);
 108
 109
 110         signal(SIGALRM, catchalarm);
 111         if (!(pwd = getpwnam(name))) {
 112                 syslog(LOG_WARNING, "No password entry for `root'\n");
 113                 bb_error_msg_and_die("No password entry for `root'\n");
 114         }
 115         pwent = *pwd;
 116 #ifdef CONFIG_FEATURE_SHADOWPASSWDS
 117         spwd = NULL;
 118         if (pwd && ((strcmp(pwd->pw_passwd, "x") == 0)
 119                                 || (strcmp(pwd->pw_passwd, "*") == 0))) {
 120                 endspent();
 121                 spwd = getspnam(name);
 122                 if (spwd) {
 123                         pwent.pw_passwd = spwd->sp_pwdp;
 124                 }
 125         }
 126 #endif                                                  /* CONFIG_FEATURE_SHADOWPASSWDS */
 127         while (1) {
 128                 cp = bb_askpass(timeout, SULOGIN_PROMPT);
 129                 if (!cp || !*cp) {
 130                         puts("\n");
 131                         fflush(stdout);
 132                         syslog(LOG_INFO, "Normal startup\n");
 133                         exit(EXIT_SUCCESS);
 134                 } else {
 135                         safe_strncpy(pass, cp, sizeof(pass));
 136                         bzero(cp, strlen(cp));
 137                 }
 138                 if (strcmp(pw_encrypt(pass, pwent.pw_passwd), pwent.pw_passwd) == 0) {
 139                         break;
 140                 }
 141                 time(&start);
 142                 now = start;
 143                 while (difftime(now, start) < FAIL_DELAY) {
 144                         sleep(FAIL_DELAY);
 145                         time(&now);
 146                 }
 147                 puts("Login incorrect");
 148                 fflush(stdout);
 149                 syslog(LOG_WARNING, "Incorrect root password\n");
 150         }
 151         bzero(pass, strlen(pass));
 152         signal(SIGALRM, SIG_DFL);
 153         puts("Entering System Maintenance Mode\n");
 154         fflush(stdout);
 155         syslog(LOG_INFO, "System Maintenance Mode\n");
 156         run_shell(pwent.pw_shell, 1, 0, 0);
 157         return (0);
 158 }