source: MondoRescue/branches/3.3/mindi-busybox/loginutils/adduser.c@ 3622

/* vi: set sw=4 ts=4: */
/*
 * adduser - add users to /etc/passwd and /etc/shadow
 *
 * Copyright (C) 1999 by Lineo, inc. and John Beppu
 * Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
//config:config ADDUSER
//config:   bool "adduser"
//config:   default y
//config:   help
//config:     Utility for creating a new user account.
//config:
//config:config FEATURE_ADDUSER_LONG_OPTIONS
//config:   bool "Enable long options"
//config:   default y
//config:   depends on ADDUSER && LONG_OPTS
//config:   help
//config:     Support long options for the adduser applet.
//config:
//config:config FEATURE_CHECK_NAMES
//config:   bool "Enable sanity check on user/group names in adduser and addgroup"
//config:   default n
//config:   depends on ADDUSER || ADDGROUP
//config:   help
//config:     Enable sanity check on user and group names in adduser and addgroup.
//config:     To avoid problems, the user or group name should consist only of
//config:     letters, digits, underscores, periods, at signs and dashes,
//config:     and not start with a dash (as defined by IEEE Std 1003.1-2001).
//config:     For compatibility with Samba machine accounts "$" is also supported
//config:     at the end of the user or group name.
//config:
//config:config LAST_ID
//config:   int "Last valid uid or gid for adduser and addgroup"
//config:   depends on ADDUSER || ADDGROUP
//config:   default 60000
//config:   help
//config:     Last valid uid or gid for adduser and addgroup
//config:
//config:config FIRST_SYSTEM_ID
//config:   int "First valid system uid or gid for adduser and addgroup"
//config:   depends on ADDUSER || ADDGROUP
//config:   range 0 LAST_ID
//config:   default 100
//config:   help
//config:     First valid system uid or gid for adduser and addgroup
//config:
//config:config LAST_SYSTEM_ID
//config:   int "Last valid system uid or gid for adduser and addgroup"
//config:   depends on ADDUSER || ADDGROUP
//config:   range FIRST_SYSTEM_ID LAST_ID
//config:   default 999
//config:   help
//config:     Last valid system uid or gid for adduser and addgroup

//applet:IF_ADDUSER(APPLET(adduser, BB_DIR_USR_SBIN, BB_SUID_DROP))

//kbuild:lib-$(CONFIG_ADDUSER) += adduser.o

//usage:#define adduser_trivial_usage
//usage:       "[OPTIONS] USER [GROUP]"
//usage:#define adduser_full_usage "\n\n"
//usage:       "Create new user, or add USER to GROUP\n"
//usage:     "\n    -h DIR      Home directory"
//usage:     "\n    -g GECOS    GECOS field"
//usage:     "\n    -s SHELL    Login shell"
//usage:     "\n    -G GRP      Add user to existing group"
//usage:     "\n    -S      Create a system user"
//usage:     "\n    -D      Don't assign a password"
//usage:     "\n    -H      Don't create home directory"
//usage:     "\n    -u UID      User id"
//usage:     "\n    -k SKEL     Skeleton directory (/etc/skel)"

#include "libbb.h"

#if CONFIG_LAST_SYSTEM_ID < CONFIG_FIRST_SYSTEM_ID
#error Bad LAST_SYSTEM_ID or FIRST_SYSTEM_ID in .config
#endif
#if CONFIG_LAST_ID < CONFIG_LAST_SYSTEM_ID
#error Bad LAST_ID or LAST_SYSTEM_ID in .config
#endif


/* #define OPT_HOME           (1 << 0) */ /* unused */
/* #define OPT_GECOS          (1 << 1) */ /* unused */
#define OPT_SHELL          (1 << 2)
#define OPT_GID            (1 << 3)
#define OPT_DONT_SET_PASS  (1 << 4)
#define OPT_SYSTEM_ACCOUNT (1 << 5)
#define OPT_DONT_MAKE_HOME (1 << 6)
#define OPT_UID            (1 << 7)
#define OPT_SKEL           (1 << 8)

/* remix */
/* recoded such that the uid may be passed in *p */
static void passwd_study(struct passwd *p)
{
    int max = CONFIG_LAST_ID;

    if (getpwnam(p->pw_name)) {
        bb_error_msg_and_die("%s '%s' in use", "user", p->pw_name);
        /* this format string is reused in adduser and addgroup */
    }

    if (!(option_mask32 & OPT_UID)) {
        if (option_mask32 & OPT_SYSTEM_ACCOUNT) {
            p->pw_uid = CONFIG_FIRST_SYSTEM_ID;
            max = CONFIG_LAST_SYSTEM_ID;
        } else {
            p->pw_uid = CONFIG_LAST_SYSTEM_ID + 1;
        }
    }
    /* check for a free uid (and maybe gid) */
    while (getpwuid(p->pw_uid) || (p->pw_gid == (gid_t)-1 && getgrgid(p->pw_uid))) {
        if (option_mask32 & OPT_UID) {
            /* -u N, cannot pick uid other than N: error */
            bb_error_msg_and_die("%s '%s' in use", "uid", itoa(p->pw_uid));
            /* this format string is reused in adduser and addgroup */
        }
        if (p->pw_uid == max) {
            bb_error_msg_and_die("no %cids left", 'u');
            /* this format string is reused in adduser and addgroup */
        }
        p->pw_uid++;
    }

    if (p->pw_gid == (gid_t)-1) {
        p->pw_gid = p->pw_uid; /* new gid = uid */
        if (getgrnam(p->pw_name)) {
            bb_error_msg_and_die("%s '%s' in use", "group", p->pw_name);
            /* this format string is reused in adduser and addgroup */
        }
    }
}

static int addgroup_wrapper(struct passwd *p, const char *group_name)
{
    char *argv[6];

    argv[0] = (char*)"addgroup";
    if (group_name) {
        /* Add user to existing group */
        argv[1] = (char*)"--";
        argv[2] = p->pw_name;
        argv[3] = (char*)group_name;
        argv[4] = NULL;
    } else {
        /* Add user to his own group with the first free gid
         * found in passwd_study.
         */
#if ENABLE_FEATURE_ADDGROUP_LONG_OPTIONS || !ENABLE_ADDGROUP
        /* We try to use --gid, not -g, because "standard" addgroup
         * has no short option -g, it has only long --gid.
         */
        argv[1] = (char*)"--gid";
#else
        /* Breaks if system in fact does NOT use busybox addgroup */
        argv[1] = (char*)"-g";
#endif
        argv[2] = utoa(p->pw_gid);
        argv[3] = (char*)"--";
        argv[4] = p->pw_name;
        argv[5] = NULL;
    }

    return spawn_and_wait(argv);
}

static void passwd_wrapper(const char *login_name) NORETURN;

static void passwd_wrapper(const char *login_name)
{
    BB_EXECLP("passwd", "passwd", "--", login_name, NULL);
    bb_error_msg_and_die("can't execute passwd, you must set password manually");
}

#if ENABLE_FEATURE_ADDUSER_LONG_OPTIONS
static const char adduser_longopts[] ALIGN1 =
        "home\0"                Required_argument "h"
        "gecos\0"               Required_argument "g"
        "shell\0"               Required_argument "s"
        "ingroup\0"             Required_argument "G"
        "disabled-password\0"   No_argument       "D"
        "empty-password\0"      No_argument       "D"
        "system\0"              No_argument       "S"
        "no-create-home\0"      No_argument       "H"
        "uid\0"                 Required_argument "u"
        "skel\0"                Required_argument "k"
        ;
#endif

/*
 * adduser will take a login_name as its first parameter.
 * home, shell, gecos:
 * can be customized via command-line parameters.
 */
int adduser_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int adduser_main(int argc UNUSED_PARAM, char **argv)
{
    struct passwd pw;
    const char *usegroup = NULL;
    char *p;
    unsigned opts;
    char *uid;
    const char *skel = "/etc/skel";

#if ENABLE_FEATURE_ADDUSER_LONG_OPTIONS
    applet_long_options = adduser_longopts;
#endif

    /* got root? */
    if (geteuid()) {
        bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
    }

    pw.pw_gecos = (char *)"Linux User,,,";
    /* We assume that newly created users "inherit" root's shell setting */
    pw.pw_shell = (char *)get_shell_name();
    pw.pw_dir = NULL;

    /* at least one and at most two non-option args */
    /* disable interactive passwd for system accounts */
    opt_complementary = "-1:?2:SD";
    opts = getopt32(argv, "h:g:s:G:DSHu:k:", &pw.pw_dir, &pw.pw_gecos, &pw.pw_shell, &usegroup, &uid, &skel);
    if (opts & OPT_UID)
        pw.pw_uid = xatou_range(uid, 0, CONFIG_LAST_ID);

    argv += optind;
    pw.pw_name = argv[0];

    if (!opts && argv[1]) {
        /* if called with two non-option arguments, adduser
         * will add an existing user to an existing group.
         */
        return addgroup_wrapper(&pw, argv[1]);
    }

    /* fill in the passwd struct */
    die_if_bad_username(pw.pw_name);
    if (!pw.pw_dir) {
        /* create string for $HOME if not specified already */
        pw.pw_dir = xasprintf("/home/%s", argv[0]);
    }
    pw.pw_passwd = (char *)"x";
    if (opts & OPT_SYSTEM_ACCOUNT) {
        if (!usegroup) {
            usegroup = "nogroup";
        }
        if (!(opts & OPT_SHELL)) {
            pw.pw_shell = (char *) "/bin/false";
        }
    }
    pw.pw_gid = usegroup ? xgroup2gid(usegroup) : -1; /* exits on failure */

    /* make sure everything is kosher and setup uid && maybe gid */
    passwd_study(&pw);

    p = xasprintf("x:%u:%u:%s:%s:%s",
            (unsigned) pw.pw_uid, (unsigned) pw.pw_gid,
            pw.pw_gecos, pw.pw_dir, pw.pw_shell);
    if (update_passwd(bb_path_passwd_file, pw.pw_name, p, NULL) < 0) {
        return EXIT_FAILURE;
    }
    if (ENABLE_FEATURE_CLEAN_UP)
        free(p);
#if ENABLE_FEATURE_SHADOWPASSWDS
    /* /etc/shadow fields:
     * 1. username
     * 2. encrypted password
     * 3. last password change (unix date (unix time/24*60*60))
     * 4. minimum days required between password changes
     * 5. maximum days password is valid
     * 6. days before password is to expire that user is warned
     * 7. days after password expires that account is disabled
     * 8. unix date when login expires (i.e. when it may no longer be used)
     */
    /* fields:     2 3  4 5     6 78 */
    p = xasprintf("!:%u:0:99999:7:::", (unsigned)(time(NULL)) / (24*60*60));
    /* ignore errors: if file is missing we suppose admin doesn't want it */
    update_passwd(bb_path_shadow_file, pw.pw_name, p, NULL);
    if (ENABLE_FEATURE_CLEAN_UP)
        free(p);
#endif

    /* add to group */
    addgroup_wrapper(&pw, usegroup);

    /* clear the umask for this process so it doesn't
     * screw up the permissions on the mkdir and chown. */
    umask(0);
    if (!(opts & OPT_DONT_MAKE_HOME)) {
        /* set the owner and group so it is owned by the new user,
         * then fix up the permissions to 2755. Can't do it before
         * since chown will clear the setgid bit */
        int mkdir_err = mkdir(pw.pw_dir, 0755);
        if (mkdir_err == 0) {
            /* New home. Copy /etc/skel to it */
            const char *args[] = {
                "chown",
                "-R",
                xasprintf("%u:%u", (int)pw.pw_uid, (int)pw.pw_gid),
                pw.pw_dir,
                NULL
            };
            /* Be silent on any errors (like: no /etc/skel) */
            if (!(opts & OPT_SKEL))
                logmode = LOGMODE_NONE;
            copy_file(skel, pw.pw_dir, FILEUTILS_RECUR);
            logmode = LOGMODE_STDIO;
            chown_main(4, (char**)args);
        }
        if ((mkdir_err != 0 && errno != EEXIST)
         || chown(pw.pw_dir, pw.pw_uid, pw.pw_gid) != 0
         || chmod(pw.pw_dir, 02755) != 0 /* set setgid bit on homedir */
        ) {
            bb_simple_perror_msg(pw.pw_dir);
        }
    }

    if (!(opts & OPT_DONT_SET_PASS)) {
        /* interactively set passwd */
        passwd_wrapper(pw.pw_name);
    }

    return EXIT_SUCCESS;
}