kadmin/kdcmgr/klookup.c

	klookup.c revision bd211b8556ef6b18ebf137419bd5555d65271664
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include <netdb.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>

/*
 * Private resolver of target and type with arguments:
 * klooukp [ target [ RR_type ] ]
 *
 * Utitilizes DNS lookups to discover domain and realm information.  This CLI
 * is used primarily by kdcmgr(1M) and kclient(1M).
 */

int
/* ARGSUSED */
main(int argc, char **argv)
{
    unsigned char answer[NS_MAXMSG], *ansp = NULL, *end, a, b, c, d;
    int len = 0, anslen, hostlen, nq, na, type, class;
    int ttl, priority, weight, port, size;
    char name[NS_MAXDNAME], *cp, *typestr = NULL;
    char nbuf[INET6_ADDRSTRLEN];
    struct __res_state stat;
    int found = 0;
    int rr_type = T_A;
    HEADER *h;

    if (argc > 3)
        exit(1);

    if (argc == 1) {
        if (gethostname(name, MAXHOSTNAMELEN) != 0)
            exit(1);
    } else {
        (void) strncpy(name, (char *)argv[1], NS_MAXDNAME);
        if (argc == 3) {
            typestr = argv[2];

            switch (*typestr) {
            case 'A':
                rr_type = T_A;
                break;
            case 'C':
                rr_type = T_CNAME;
                break;
            case 'I':
                rr_type = T_A;
                break;
            case 'P':
                rr_type = T_PTR;
                (void) sscanf(name, "%d.%d.%d.%d",
                    &a, &b, &c, &d);
                (void) sprintf(name, "%d.%d.%d.%d.in-addr.arpa",
                    d, c, b, a);
                break;
            case 'S':
                rr_type = T_SRV;
                break;
            default:
                exit(1);
            }
        }
    }

    (void) memset(&stat, 0, sizeof (stat));

    if (res_ninit(&stat) == -1)
        exit(1);

    anslen = sizeof (answer);
    len = res_nsearch(&stat, name, C_IN, rr_type, answer, anslen);

    if (len < sizeof (HEADER)) {
        res_ndestroy(&stat);
        exit(1);
    }

    ansp = answer;
    end = ansp + anslen;

    /* LINTED */
    h = (HEADER *)answer;
    nq = ntohs(h->qdcount);
    na = ntohs(h->ancount);
    ansp += HFIXEDSZ;

    if (nq != 1 || na < 1) {
        res_ndestroy(&stat);
        exit(1);
    }

    hostlen = sizeof (name);
    len = dn_expand(answer, end, ansp, name, hostlen);
    if (len < 0) {
        res_ndestroy(&stat);
        exit(1);
    }

    ansp += len + QFIXEDSZ;

    if (ansp > end) {
        res_ndestroy(&stat);
        exit(1);
    }

    while (na-- > 0 && ansp < end) {

        len = dn_expand(answer, end, ansp, name, hostlen);

        if (len < 0)
            continue;
        ansp += len;            /* name */
        NS_GET16(type, ansp);       /* type */
        NS_GET16(class, ansp);      /* class */
        NS_GET32(ttl, ansp);        /* ttl */
        NS_GET16(size, ansp);       /* size */

        if ((ansp + size) > end) {
            res_ndestroy(&stat);
            exit(1);
        }
        if (type == T_SRV) {
            NS_GET16(priority, ansp);
            NS_GET16(weight, ansp);
            NS_GET16(port, ansp);
            len = dn_expand(answer, end, ansp, name, hostlen);
            if (len < 0) {
                res_ndestroy(&stat);
                exit(1);
            }
            for (cp = name; *cp; cp++) {
                *cp = tolower(*cp);
            }
            (void) printf("%s %d\n", name, port);
        } else if (typestr && *typestr == 'I') {
            (void) inet_ntop(AF_INET, (void *)ansp, nbuf,
                INET6_ADDRSTRLEN);
            (void) strncpy(name, nbuf, MAXHOSTNAMELEN);
        } else if (type == T_PTR) {
            len = dn_expand(answer, end, ansp, name, hostlen);
            if (len < 0) {
                res_ndestroy(&stat);
                exit(1);
            }
        }
        ansp += len;
        if (type == rr_type && class == C_IN) {
            found = 1;
            if (type != T_SRV)
                break;
        }
    }

    if (found != 1) {
        res_ndestroy(&stat);
        exit(1);
    }

    for (cp = name; *cp; cp++) {
        *cp = tolower(*cp);
    }

    if (type != T_SRV)
        (void) printf("%s\n", name);

    res_ndestroy(&stat);

    return (0);
}