release/src/router/busybox/loginutils/adduser.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * adduser - add users to /etc/passwd and /etc/shadow
   4  *
   5  * Copyright (C) 1999 by Lineo, inc. and John Beppu
   6  * Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org>
   7  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9  */
  10
  11 //usage:#define adduser_trivial_usage
  12 //usage:       "[OPTIONS] USER [GROUP]"
  13 //usage:#define adduser_full_usage "\n\n"
  14 //usage:       "Create new user, or add USER to GROUP\n"
  15 //usage:     "\n        -h DIR          Home directory"
  16 //usage:     "\n        -g GECOS        GECOS field"
  17 //usage:     "\n        -s SHELL        Login shell"
  18 //usage:     "\n        -G GRP          Add user to existing group"
  19 //usage:     "\n        -S              Create a system user"
  20 //usage:     "\n        -D              Don't assign a password"
  21 //usage:     "\n        -H              Don't create home directory"
  22 //usage:     "\n        -u UID          User id"
  23
  24 #include "libbb.h"
  25
  26 #if CONFIG_LAST_SYSTEM_ID < CONFIG_FIRST_SYSTEM_ID
  27 #error Bad LAST_SYSTEM_ID or FIRST_SYSTEM_ID in .config
  28 #endif
  29
  30 /* #define OPT_HOME           (1 << 0) */ /* unused */
  31 /* #define OPT_GECOS          (1 << 1) */ /* unused */
  32 #define OPT_SHELL          (1 << 2)
  33 #define OPT_GID            (1 << 3)
  34 #define OPT_DONT_SET_PASS  (1 << 4)
  35 #define OPT_SYSTEM_ACCOUNT (1 << 5)
  36 #define OPT_DONT_MAKE_HOME (1 << 6)
  37 #define OPT_UID            (1 << 7)
  38
  39 /* We assume UID_T_MAX == INT_MAX */
  40 /* remix */
  41 /* recoded such that the uid may be passed in *p */
  42 static void passwd_study(struct passwd *p)
  43 {
  44         int max = UINT_MAX;
  45
  46         if (getpwnam(p->pw_name)) {
  47                 bb_error_msg_and_die("%s '%s' in use", "user", p->pw_name);
  48                 /* this format string is reused in adduser and addgroup */
  49         }
  50
  51         if (!(option_mask32 & OPT_UID)) {
  52                 if (option_mask32 & OPT_SYSTEM_ACCOUNT) {
  53                         p->pw_uid = CONFIG_FIRST_SYSTEM_ID;
  54                         max = CONFIG_LAST_SYSTEM_ID;
  55                 } else {
  56                         p->pw_uid = CONFIG_LAST_SYSTEM_ID + 1;
  57                         max = 64999;
  58                 }
  59         }
  60         /* check for a free uid (and maybe gid) */
  61         while (getpwuid(p->pw_uid) || (p->pw_gid == (gid_t)-1 && getgrgid(p->pw_uid))) {
  62                 if (option_mask32 & OPT_UID) {
  63                         /* -u N, cannot pick uid other than N: error */
  64                         bb_error_msg_and_die("%s '%s' in use", "uid", itoa(p->pw_uid));
  65                         /* this format string is reused in adduser and addgroup */
  66                 }
  67                 if (p->pw_uid == max) {
  68                         bb_error_msg_and_die("no %cids left", 'u');
  69                         /* this format string is reused in adduser and addgroup */
  70                 }
  71                 p->pw_uid++;
  72         }
  73
  74         if (p->pw_gid == (gid_t)-1) {
  75                 p->pw_gid = p->pw_uid; /* new gid = uid */
  76                 if (getgrnam(p->pw_name)) {
  77                         bb_error_msg_and_die("%s '%s' in use", "group", p->pw_name);
  78                         /* this format string is reused in adduser and addgroup */
  79                 }
  80         }
  81 }
  82
  83 static int addgroup_wrapper(struct passwd *p, const char *group_name)
  84 {
  85         char *argv[6];
  86
  87         argv[0] = (char*)"addgroup";
  88         if (group_name) {
  89                 /* Add user to existing group */
  90                 argv[1] = (char*)"--";
  91                 argv[2] = p->pw_name;
  92                 argv[3] = (char*)group_name;
  93                 argv[4] = NULL;
  94         } else {
  95                 /* Add user to his own group with the first free gid
  96                  * found in passwd_study.
  97                  */
  98 #if ENABLE_FEATURE_ADDGROUP_LONG_OPTIONS || !ENABLE_ADDGROUP
  99                 /* We try to use --gid, not -g, because "standard" addgroup
 100                  * has no short option -g, it has only long --gid.
 101                  */
 102                 argv[1] = (char*)"--gid";
 103 #else
 104                 /* Breaks if system in fact does NOT use busybox addgroup */
 105                 argv[1] = (char*)"-g";
 106 #endif
 107                 argv[2] = utoa(p->pw_gid);
 108                 argv[3] = (char*)"--";
 109                 argv[4] = p->pw_name;
 110                 argv[5] = NULL;
 111         }
 112
 113         return spawn_and_wait(argv);
 114 }
 115
 116 static void passwd_wrapper(const char *login_name) NORETURN;
 117
 118 static void passwd_wrapper(const char *login_name)
 119 {
 120         BB_EXECLP("passwd", "passwd", "--", login_name, NULL);
 121         bb_error_msg_and_die("can't execute passwd, you must set password manually");
 122 }
 123
 124 #if ENABLE_FEATURE_ADDUSER_LONG_OPTIONS
 125 static const char adduser_longopts[] ALIGN1 =
 126                 "home\0"                Required_argument "h"
 127                 "gecos\0"               Required_argument "g"
 128                 "shell\0"               Required_argument "s"
 129                 "ingroup\0"             Required_argument "G"
 130                 "disabled-password\0"   No_argument       "D"
 131                 "empty-password\0"      No_argument       "D"
 132                 "system\0"              No_argument       "S"
 133                 "no-create-home\0"      No_argument       "H"
 134                 "uid\0"                 Required_argument "u"
 135                 ;
 136 #endif
 137
 138 /*
 139  * adduser will take a login_name as its first parameter.
 140  * home, shell, gecos:
 141  * can be customized via command-line parameters.
 142  */
 143 int adduser_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 144 int adduser_main(int argc UNUSED_PARAM, char **argv)
 145 {
 146         struct passwd pw;
 147         const char *usegroup = NULL;
 148         char *p;
 149         unsigned opts;
 150
 151 #if ENABLE_FEATURE_ADDUSER_LONG_OPTIONS
 152         applet_long_options = adduser_longopts;
 153 #endif
 154
 155         /* got root? */
 156         if (geteuid()) {
 157                 bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
 158         }
 159
 160         pw.pw_gecos = (char *)"Linux User,,,";
 161         /* We assume that newly created users "inherit" root's shell setting */
 162         pw.pw_shell = (char *)get_shell_name();
 163         pw.pw_dir = NULL;
 164
 165         /* at most two non-option args */
 166         /* disable interactive passwd for system accounts */
 167         opt_complementary = "?2:SD:u+";
 168         if (sizeof(pw.pw_uid) == sizeof(int)) {
 169                 opts = getopt32(argv, "h:g:s:G:DSHu:", &pw.pw_dir, &pw.pw_gecos, &pw.pw_shell, &usegroup, &pw.pw_uid);
 170         } else {
 171                 unsigned uid;
 172                 opts = getopt32(argv, "h:g:s:G:DSHu:", &pw.pw_dir, &pw.pw_gecos, &pw.pw_shell, &usegroup, &uid);
 173                 if (opts & OPT_UID) {
 174                         pw.pw_uid = uid;
 175                 }
 176         }
 177         argv += optind;
 178         pw.pw_name = argv[0];
 179
 180         if (!opts && argv[1]) {
 181                 /* if called with two non-option arguments, adduser
 182                  * will add an existing user to an existing group.
 183                  */
 184                 return addgroup_wrapper(&pw, argv[1]);
 185         }
 186
 187         /* fill in the passwd struct */
 188         die_if_bad_username(pw.pw_name);
 189         if (!pw.pw_dir) {
 190                 /* create string for $HOME if not specified already */
 191                 pw.pw_dir = xasprintf("/home/%s", argv[0]);
 192         }
 193         pw.pw_passwd = (char *)"x";
 194         if (opts & OPT_SYSTEM_ACCOUNT) {
 195                 if (!usegroup) {
 196                         usegroup = "nogroup";
 197                 }
 198                 if (!(opts & OPT_SHELL)) {
 199                         pw.pw_shell = (char *) "/bin/false";
 200                 }
 201         }
 202         pw.pw_gid = usegroup ? xgroup2gid(usegroup) : -1; /* exits on failure */
 203
 204         /* make sure everything is kosher and setup uid && maybe gid */
 205         passwd_study(&pw);
 206
 207         p = xasprintf("x:%u:%u:%s:%s:%s",
 208                         (unsigned) pw.pw_uid, (unsigned) pw.pw_gid,
 209                         pw.pw_gecos, pw.pw_dir, pw.pw_shell);
 210         if (update_passwd(bb_path_passwd_file, pw.pw_name, p, NULL) < 0) {
 211                 return EXIT_FAILURE;
 212         }
 213         if (ENABLE_FEATURE_CLEAN_UP)
 214                 free(p);
 215 #if ENABLE_FEATURE_SHADOWPASSWDS
 216         /* /etc/shadow fields:
 217          * 1. username
 218          * 2. encrypted password
 219          * 3. last password change (unix date (unix time/24*60*60))
 220          * 4. minimum days required between password changes
 221          * 5. maximum days password is valid
 222          * 6. days before password is to expire that user is warned
 223          * 7. days after password expires that account is disabled
 224          * 8. unix date when login expires (i.e. when it may no longer be used)
 225          */
 226         /* fields:     2 3  4 5     6 78 */
 227         p = xasprintf("!:%u:0:99999:7:::", (unsigned)(time(NULL)) / (24*60*60));
 228         /* ignore errors: if file is missing we suppose admin doesn't want it */
 229         update_passwd(bb_path_shadow_file, pw.pw_name, p, NULL);
 230         if (ENABLE_FEATURE_CLEAN_UP)
 231                 free(p);
 232 #endif
 233
 234         /* add to group */
 235         addgroup_wrapper(&pw, usegroup);
 236
 237         /* clear the umask for this process so it doesn't
 238          * screw up the permissions on the mkdir and chown. */
 239         umask(0);
 240         if (!(opts & OPT_DONT_MAKE_HOME)) {
 241                 /* set the owner and group so it is owned by the new user,
 242                  * then fix up the permissions to 2755. Can't do it before
 243                  * since chown will clear the setgid bit */
 244                 int mkdir_err = mkdir(pw.pw_dir, 0755);
 245                 if (mkdir_err == 0) {
 246                         /* New home. Copy /etc/skel to it */
 247                         const char *args[] = {
 248                                 "chown",
 249                                 "-R",
 250                                 xasprintf("%u:%u", (int)pw.pw_uid, (int)pw.pw_gid),
 251                                 pw.pw_dir,
 252                                 NULL
 253                         };
 254                         /* Be silent on any errors (like: no /etc/skel) */
 255                         logmode = LOGMODE_NONE;
 256                         copy_file("/etc/skel", pw.pw_dir, FILEUTILS_RECUR);
 257                         logmode = LOGMODE_STDIO;
 258                         chown_main(4, (char**)args);
 259                 }
 260                 if ((mkdir_err != 0 && errno != EEXIST)
 261                  || chown(pw.pw_dir, pw.pw_uid, pw.pw_gid) != 0
 262                  || chmod(pw.pw_dir, 02755) != 0 /* set setgid bit on homedir */
 263                 ) {
 264                         bb_simple_perror_msg(pw.pw_dir);
 265                 }
 266         }
 267
 268         if (!(opts & OPT_DONT_SET_PASS)) {
 269                 /* interactively set passwd */
 270                 passwd_wrapper(pw.pw_name);
 271         }
 272
 273         return EXIT_SUCCESS;
 274 }