source: MondoRescue/branches/2.2.5/mindi-busybox/coreutils/id.c@ 1765

/* vi: set sw=4 ts=4: */
/*
 * Mini id implementation for busybox
 *
 * Copyright (C) 2000 by Randolph Chung <tausq@debian.org>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

/* BB_AUDIT SUSv3 _NOT_ compliant -- option -G is not currently supported. */
/* Hacked by Tito Ragusa (C) 2004 to handle usernames of whatever length and to
 * be more similar to GNU id.
 * -Z option support: by Yuichi Nakamura <ynakam@hitachisoft.jp>
 */

#include "libbb.h"

#define PRINT_REAL        1
#define NAME_NOT_NUMBER   2
#define JUST_USER         4
#define JUST_GROUP        8
#if ENABLE_SELINUX
#define JUST_CONTEXT     16
#endif

static int printf_full(unsigned int id, const char *arg, const char prefix)
{
    const char *fmt = "%cid=%u";
    int status = EXIT_FAILURE;

    if (arg) {
        fmt = "%cid=%u(%s)";
        status = EXIT_SUCCESS;
    }
    printf(fmt, prefix, id, arg);
    return status;
}

int id_main(int argc, char **argv);
int id_main(int argc, char **argv)
{
    struct passwd *p;
    uid_t uid;
    gid_t gid;
    unsigned long flags;
    short status;
#if ENABLE_SELINUX
    security_context_t scontext;
#endif
    /* Don't allow -n -r -nr -ug -rug -nug -rnug */
    /* Don't allow more than one username */
    opt_complementary = "?1:u--g:g--u:r?ug:n?ug" USE_SELINUX(":u--Z:Z--u:g--Z:Z--g");
    flags = getopt32(argv, "rnug" USE_SELINUX("Z"));

    /* This values could be overwritten later */
    uid = geteuid();
    gid = getegid();
    if (flags & PRINT_REAL) {
        uid = getuid();
        gid = getgid();
    }

    if (argv[optind]) {
        p = getpwnam(argv[optind]);
        /* xuname2uid is needed because it exits on failure */
        uid = xuname2uid(argv[optind]);
        gid = p->pw_gid;
        /* in this case PRINT_REAL is the same */
    }

    if (flags & (JUST_GROUP | JUST_USER USE_SELINUX(| JUST_CONTEXT))) {
        /* JUST_GROUP and JUST_USER are mutually exclusive */
        if (flags & NAME_NOT_NUMBER) {
            /* bb_getXXXid(-1) exit on failure, puts cannot segfault */
            puts((flags & JUST_USER) ? bb_getpwuid(NULL, -1, uid) : bb_getgrgid(NULL, -1, gid));
        } else {
            if (flags & JUST_USER) {
                printf("%u\n", uid);
            }
            if (flags & JUST_GROUP) {
                printf("%u\n", gid);
            }
        }

#if ENABLE_SELINUX
        if (flags & JUST_CONTEXT) {
            selinux_or_die();
            if (argc - optind == 1) {
                bb_error_msg_and_die("user name can't be passed with -Z");
            }

            if (getcon(&scontext)) {
                bb_error_msg_and_die("can't get process context");
            }
            printf("%s\n", scontext);
        }
#endif
        /* exit */
        fflush_stdout_and_exit(EXIT_SUCCESS);
    }

    /* Print full info like GNU id */
    /* bb_getpwuid(0) doesn't exit on failure (returns NULL) */
    status = printf_full(uid, bb_getpwuid(NULL, 0, uid), 'u');
    putchar(' ');
    status |= printf_full(gid, bb_getgrgid(NULL, 0, gid), 'g');

#if ENABLE_SELINUX
    if (is_selinux_enabled()) {
        security_context_t mysid;
        const char *context;

        context = "unknown";
        getcon(&mysid);
        if (mysid) {
            context = alloca(strlen(mysid) + 1);
            strcpy((char*)context, mysid);
            freecon(mysid);
        }
        printf(" context=%s", context);
    }
#endif

    putchar('\n');
    fflush_stdout_and_exit(status);
}