LXR 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//config:config ADDUSER
  11//config:       bool "adduser (15 kb)"
  12//config:       default y
  13//config:       select LONG_OPTS
  14//config:       help
  15//config:       Utility for creating a new user account.
  16//config:
  17//config:config FEATURE_CHECK_NAMES
  18//config:       bool "Enable sanity check on user/group names in adduser and addgroup"
  19//config:       default n
  20//config:       depends on ADDUSER || ADDGROUP
  21//config:       help
  22//config:       Enable sanity check on user and group names in adduser and addgroup.
  23//config:       To avoid problems, the user or group name should consist only of
  24//config:       letters, digits, underscores, periods, at signs and dashes,
  25//config:       and not start with a dash (as defined by IEEE Std 1003.1-2001).
  26//config:       For compatibility with Samba machine accounts "$" is also supported
  27//config:       at the end of the user or group name.
  28//config:
  29//config:config LAST_ID
  30//config:       int "Last valid uid or gid for adduser and addgroup"
  31//config:       depends on ADDUSER || ADDGROUP
  32//config:       default 60000
  33//config:       help
  34//config:       Last valid uid or gid for adduser and addgroup
  35//config:
  36//config:config FIRST_SYSTEM_ID
  37//config:       int "First valid system uid or gid for adduser and addgroup"
  38//config:       depends on ADDUSER || ADDGROUP
  39//config:       range 0 LAST_ID
  40//config:       default 100
  41//config:       help
  42//config:       First valid system uid or gid for adduser and addgroup
  43//config:
  44//config:config LAST_SYSTEM_ID
  45//config:       int "Last valid system uid or gid for adduser and addgroup"
  46//config:       depends on ADDUSER || ADDGROUP
  47//config:       range FIRST_SYSTEM_ID LAST_ID
  48//config:       default 999
  49//config:       help
  50//config:       Last valid system uid or gid for adduser and addgroup
  51
  52//applet:IF_ADDUSER(APPLET_NOEXEC(adduser, adduser, BB_DIR_USR_SBIN, BB_SUID_DROP, adduser))
  53
  54//kbuild:lib-$(CONFIG_ADDUSER) += adduser.o
  55
  56//usage:#define adduser_trivial_usage
  57//usage:       "[OPTIONS] USER [GROUP]"
  58//usage:#define adduser_full_usage "\n\n"
  59//usage:       "Create new user, or add USER to GROUP\n"
  60//usage:     "\n        -h DIR          Home directory"
  61//usage:     "\n        -g GECOS        GECOS field"
  62//usage:     "\n        -s SHELL        Login shell"
  63//usage:     "\n        -G GRP          Group"
  64//usage:     "\n        -S              Create a system user"
  65//usage:     "\n        -D              Don't assign a password"
  66//usage:     "\n        -H              Don't create home directory"
  67//usage:     "\n        -u UID          User id"
  68//usage:     "\n        -k SKEL         Skeleton directory (/etc/skel)"
  69
  70#include "libbb.h"
  71
  72#if CONFIG_LAST_SYSTEM_ID < CONFIG_FIRST_SYSTEM_ID
  73#error Bad LAST_SYSTEM_ID or FIRST_SYSTEM_ID in .config
  74#endif
  75#if CONFIG_LAST_ID < CONFIG_LAST_SYSTEM_ID
  76#error Bad LAST_ID or LAST_SYSTEM_ID in .config
  77#endif
  78
  79
  80/* #define OPT_HOME           (1 << 0) */ /* unused */
  81/* #define OPT_GECOS          (1 << 1) */ /* unused */
  82#define OPT_SHELL          (1 << 2)
  83#define OPT_GID            (1 << 3)
  84#define OPT_DONT_SET_PASS  (1 << 4)
  85#define OPT_SYSTEM_ACCOUNT (1 << 5)
  86#define OPT_DONT_MAKE_HOME (1 << 6)
  87#define OPT_UID            (1 << 7)
  88#define OPT_SKEL           (1 << 8)
  89
  90/* remix */
  91/* recoded such that the uid may be passed in *p */
  92static void passwd_study(struct passwd *p)
  93{
  94        int max = CONFIG_LAST_ID;
  95
  96        if (getpwnam(p->pw_name)) {
  97                bb_error_msg_and_die("%s '%s' in use", "user", p->pw_name);
  98                /* this format string is reused in adduser and addgroup */
  99        }
 100
 101        if (!(option_mask32 & OPT_UID)) {
 102                if (option_mask32 & OPT_SYSTEM_ACCOUNT) {
 103                        p->pw_uid = CONFIG_FIRST_SYSTEM_ID;
 104                        max = CONFIG_LAST_SYSTEM_ID;
 105                } else {
 106                        p->pw_uid = CONFIG_LAST_SYSTEM_ID + 1;
 107                }
 108        }
 109        /* check for a free uid (and maybe gid) */
 110        while (getpwuid(p->pw_uid) || (p->pw_gid == (gid_t)-1 && getgrgid(p->pw_uid))) {
 111                if (option_mask32 & OPT_UID) {
 112                        /* -u N, cannot pick uid other than N: error */
 113                        bb_error_msg_and_die("%s '%s' in use", "uid", itoa(p->pw_uid));
 114                        /* this format string is reused in adduser and addgroup */
 115                }
 116                if (p->pw_uid == max) {
 117                        bb_error_msg_and_die("no %cids left", 'u');
 118                        /* this format string is reused in adduser and addgroup */
 119                }
 120                p->pw_uid++;
 121        }
 122
 123        if (p->pw_gid == (gid_t)-1) {
 124                p->pw_gid = p->pw_uid; /* new gid = uid */
 125                if (getgrnam(p->pw_name)) {
 126                        bb_error_msg_and_die("%s '%s' in use", "group", p->pw_name);
 127                        /* this format string is reused in adduser and addgroup */
 128                }
 129        }
 130}
 131
 132static int addgroup_wrapper(struct passwd *p, const char *group_name)
 133{
 134        char *argv[6];
 135
 136        argv[0] = (char*)"addgroup";
 137        if (group_name) {
 138                /* Add user to existing group */
 139                argv[1] = (char*)"--";
 140                argv[2] = p->pw_name;
 141                argv[3] = (char*)group_name;
 142                argv[4] = NULL;
 143        } else {
 144                /* Add user to his own group with the first free gid
 145                 * found in passwd_study.
 146                 */
 147                argv[1] = (char*)"--gid";
 148                argv[2] = utoa(p->pw_gid);
 149                argv[3] = (char*)"--";
 150                argv[4] = p->pw_name;
 151                argv[5] = NULL;
 152        }
 153
 154        return spawn_and_wait(argv);
 155}
 156
 157static void passwd_wrapper(const char *login_name) NORETURN;
 158
 159static void passwd_wrapper(const char *login_name)
 160{
 161        BB_EXECLP("passwd", "passwd", "--", login_name, NULL);
 162        bb_simple_error_msg_and_die("can't execute passwd, you must set password manually");
 163}
 164
 165//FIXME: upstream adduser has no short options! NOT COMPATIBLE!
 166static const char adduser_longopts[] ALIGN1 =
 167                "home\0"                Required_argument "h"
 168                "gecos\0"               Required_argument "g"
 169                "shell\0"               Required_argument "s"
 170                "ingroup\0"             Required_argument "G"
 171                "disabled-password\0"   No_argument       "D"
 172                "empty-password\0"      No_argument       "D"
 173                "system\0"              No_argument       "S"
 174                "no-create-home\0"      No_argument       "H"
 175                "uid\0"                 Required_argument "u"
 176                "skel\0"                Required_argument "k"
 177                ;
 178
 179/*
 180 * adduser will take a login_name as its first parameter.
 181 * home, shell, gecos:
 182 * can be customized via command-line parameters.
 183 */
 184int adduser_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 185int adduser_main(int argc UNUSED_PARAM, char **argv)
 186{
 187        struct passwd pw;
 188        const char *usegroup = NULL;
 189        char *p;
 190        unsigned opts;
 191        char *uid;
 192        const char *skel = "/etc/skel";
 193
 194        /* got root? */
 195        if (geteuid()) {
 196                bb_simple_error_msg_and_die(bb_msg_perm_denied_are_you_root);
 197        }
 198
 199        pw.pw_gecos = (char *)"Linux User,,,";
 200        /* We assume that newly created users "inherit" root's shell setting */
 201        pw.pw_shell = xstrdup(get_shell_name()); /* might come from getpwnam(), need to make a copy */
 202        pw.pw_dir = NULL;
 203
 204        opts = getopt32long(argv, "^"
 205                        "h:g:s:G:DSHu:k:"
 206                        /* at least one and at most two non-option args */
 207                        /* disable interactive passwd for system accounts */
 208                        "\0" "-1:?2:SD",
 209                        adduser_longopts,
 210                        &pw.pw_dir, &pw.pw_gecos, &pw.pw_shell,
 211                        &usegroup, &uid, &skel
 212        );
 213        if (opts & OPT_UID)
 214                pw.pw_uid = xatou_range(uid, 0, CONFIG_LAST_ID);
 215
 216        argv += optind;
 217        pw.pw_name = argv[0];
 218
 219        if (!opts && argv[1]) {
 220                /* if called with two non-option arguments, adduser
 221                 * will add an existing user to an existing group.
 222                 */
 223                return addgroup_wrapper(&pw, argv[1]);
 224        }
 225
 226        /* fill in the passwd struct */
 227        die_if_bad_username(pw.pw_name);
 228        if (!pw.pw_dir) {
 229                /* create string for $HOME if not specified already */
 230                pw.pw_dir = xasprintf("/home/%s", argv[0]);
 231        }
 232        pw.pw_passwd = (char *)"x";
 233        if (opts & OPT_SYSTEM_ACCOUNT) {
 234                if (!usegroup) {
 235                        usegroup = "nogroup";
 236                }
 237                if (!(opts & OPT_SHELL)) {
 238                        pw.pw_shell = (char *) "/bin/false";
 239                }
 240        }
 241        pw.pw_gid = usegroup ? xgroup2gid(usegroup) : -1; /* exits on failure */
 242
 243        /* make sure everything is kosher and setup uid && maybe gid */
 244        passwd_study(&pw);
 245
 246        p = xasprintf("x:%u:%u:%s:%s:%s",
 247                        (unsigned) pw.pw_uid, (unsigned) pw.pw_gid,
 248                        pw.pw_gecos, pw.pw_dir, pw.pw_shell);
 249        if (update_passwd(bb_path_passwd_file, pw.pw_name, p, NULL) < 0) {
 250                return EXIT_FAILURE;
 251        }
 252        if (ENABLE_FEATURE_CLEAN_UP)
 253                free(p);
 254#if ENABLE_FEATURE_SHADOWPASSWDS
 255        /* /etc/shadow fields:
 256         * 1. username
 257         * 2. encrypted password
 258         * 3. last password change (unix date (unix time/24*60*60))
 259         * 4. minimum days required between password changes
 260         * 5. maximum days password is valid
 261         * 6. days before password is to expire that user is warned
 262         * 7. days after password expires that account is disabled
 263         * 8. unix date when login expires (i.e. when it may no longer be used)
 264         */
 265        /* fields:     2 3  4 5     6 78 */
 266        p = xasprintf("!:%u:0:99999:7:::", (unsigned)(time(NULL)) / (24*60*60));
 267        /* ignore errors: if file is missing we suppose admin doesn't want it */
 268        update_passwd(bb_path_shadow_file, pw.pw_name, p, NULL);
 269        if (ENABLE_FEATURE_CLEAN_UP)
 270                free(p);
 271#endif
 272
 273        /* add to group */
 274        addgroup_wrapper(&pw, usegroup);
 275
 276        /* clear the umask for this process so it doesn't
 277         * screw up the permissions on the mkdir and chown. */
 278        umask(0);
 279        if (!(opts & OPT_DONT_MAKE_HOME)) {
 280                /* set the owner and group so it is owned by the new user,
 281                 * then fix up the permissions to 2755. Can't do it before
 282                 * since chown will clear the setgid bit */
 283                int mkdir_err = mkdir(pw.pw_dir, 0755);
 284                if (mkdir_err == 0) {
 285                        /* New home. Copy /etc/skel to it */
 286                        const char *args[] = {
 287                                "chown",
 288                                "-R",
 289                                xasprintf("%u:%u", (int)pw.pw_uid, (int)pw.pw_gid),
 290                                pw.pw_dir,
 291                                NULL
 292                        };
 293                        /* Be silent on any errors (like: no /etc/skel) */
 294                        if (!(opts & OPT_SKEL))
 295                                logmode = LOGMODE_NONE;
 296                        copy_file(skel, pw.pw_dir, FILEUTILS_RECUR);
 297                        logmode = LOGMODE_STDIO;
 298                        chown_main(4, (char**)args);
 299                }
 300                if ((mkdir_err != 0 && errno != EEXIST)
 301                 || chown(pw.pw_dir, pw.pw_uid, pw.pw_gid) != 0
 302                 || chmod(pw.pw_dir, 02755) != 0 /* set setgid bit on homedir */
 303                ) {
 304                        bb_simple_perror_msg(pw.pw_dir);
 305                }
 306        }
 307
 308        if (!(opts & OPT_DONT_SET_PASS)) {
 309                /* interactively set passwd */
 310                passwd_wrapper(pw.pw_name);
 311        }
 312
 313        return EXIT_SUCCESS;
 314}
 315