common/nameser/ns_print.c

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1996-1999 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef lint
static const char rcsid[] = "$Id: ns_print.c,v 1.12 2009/03/03 05:29:58 each Exp $";
#endif

/* Import. */

#include "port_before.h"

#include <sys/types.h>
#include <sys/socket.h>

#include <netinet/in.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>

#include <isc/assertions.h>
#include <isc/dst.h>
#include <errno.h>
#include <resolv.h>
#include <string.h>
#include <ctype.h>

#include "port_after.h"

#ifdef SPRINTF_CHAR
# define SPRINTF(x) strlen(sprintf/**/x)
#else
# define SPRINTF(x) ((size_t)sprintf x)
#endif

/* Forward. */

static size_t   prune_origin(const char *name, const char *origin);
static int  charstr(const u_char *rdata, const u_char *edata,
            char **buf, size_t *buflen);
static int  addname(const u_char *msg, size_t msglen,
            const u_char **p, const char *origin,
            char **buf, size_t *buflen);
static void addlen(size_t len, char **buf, size_t *buflen);
static int  addstr(const char *src, size_t len,
               char **buf, size_t *buflen);
static int  addtab(size_t len, size_t target, int spaced,
               char **buf, size_t *buflen);

/* Macros. */

#define T(x) \
    do { \
        if ((x) < 0) \
            return (-1); \
    } while (0)

static const char base32hex[] =
        "0123456789ABCDEFGHIJKLMNOPQRSTUV=0123456789abcdefghijklmnopqrstuv";

/* Public. */

/*%
 *  Convert an RR to presentation format.
 *
 * return:
 *\li   Number of characters written to buf, or -1 (check errno).
 */
int
ns_sprintrr(const ns_msg *handle, const ns_rr *rr,
        const char *name_ctx, const char *origin,
        char *buf, size_t buflen)
{
    int n;

    n = ns_sprintrrf(ns_msg_base(*handle), ns_msg_size(*handle),
             ns_rr_name(*rr), ns_rr_class(*rr), ns_rr_type(*rr),
             ns_rr_ttl(*rr), ns_rr_rdata(*rr), ns_rr_rdlen(*rr),
             name_ctx, origin, buf, buflen);
    return (n);
}

/*%
 *  Convert the fields of an RR into presentation format.
 *
 * return:
 *\li   Number of characters written to buf, or -1 (check errno).
 */
int
ns_sprintrrf(const u_char *msg, size_t msglen,
        const char *name, ns_class class, ns_type type,
        u_long ttl, const u_char *rdata, size_t rdlen,
        const char *name_ctx, const char *origin,
        char *buf, size_t buflen)
{
    const char *obuf = buf;
    const u_char *edata = rdata + rdlen;
    int spaced = 0;

    const char *comment;
    char tmp[100];
    int len, x;

    /*
     * Owner.
     */
    if (name_ctx != NULL && ns_samename(name_ctx, name) == 1) {
        T(addstr("\t\t\t", 3, &buf, &buflen));
    } else {
        len = prune_origin(name, origin);
        if (*name == '\0') {
            goto root;
        } else if (len == 0) {
            T(addstr("@\t\t\t", 4, &buf, &buflen));
        } else {
            T(addstr(name, len, &buf, &buflen));
            /* Origin not used or not root, and no trailing dot? */
            if (((origin == NULL || origin[0] == '\0') ||
                (origin[0] != '.' && origin[1] != '\0' &&
                name[len] == '\0')) && name[len - 1] != '.') {
 root:
                T(addstr(".", 1, &buf, &buflen));
                len++;
            }
            T(spaced = addtab(len, 24, spaced, &buf, &buflen));
        }
    }

    /*
     * TTL, Class, Type.
     */
    T(x = ns_format_ttl(ttl, buf, buflen));
    addlen(x, &buf, &buflen);
    len = SPRINTF((tmp, " %s %s", p_class(class), p_type(type)));
    T(addstr(tmp, len, &buf, &buflen));
    T(spaced = addtab(x + len, 16, spaced, &buf, &buflen));

    /*
     * RData.
     */
    switch (type) {
    case ns_t_a:
        if (rdlen != (size_t)NS_INADDRSZ)
            goto formerr;
        (void) inet_ntop(AF_INET, rdata, buf, buflen);
        addlen(strlen(buf), &buf, &buflen);
        break;

    case ns_t_cname:
    case ns_t_mb:
    case ns_t_mg:
    case ns_t_mr:
    case ns_t_ns:
    case ns_t_ptr:
    case ns_t_dname:
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
        break;

    case ns_t_hinfo:
    case ns_t_isdn:
        /* First word. */
        T(len = charstr(rdata, edata, &buf, &buflen));
        if (len == 0)
            goto formerr;
        rdata += len;
        T(addstr(" ", 1, &buf, &buflen));


        /* Second word, optional in ISDN records. */
        if (type == ns_t_isdn && rdata == edata)
            break;

        T(len = charstr(rdata, edata, &buf, &buflen));
        if (len == 0)
            goto formerr;
        rdata += len;
        break;

    case ns_t_soa: {
        u_long t;

        /* Server name. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
        T(addstr(" ", 1, &buf, &buflen));

        /* Administrator name. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
        T(addstr(" (\n", 3, &buf, &buflen));
        spaced = 0;

        if ((edata - rdata) != 5*NS_INT32SZ)
            goto formerr;

        /* Serial number. */
        t = ns_get32(rdata);  rdata += NS_INT32SZ;
        T(addstr("\t\t\t\t\t", 5, &buf, &buflen));
        len = SPRINTF((tmp, "%lu", t));
        T(addstr(tmp, len, &buf, &buflen));
        T(spaced = addtab(len, 16, spaced, &buf, &buflen));
        T(addstr("; serial\n", 9, &buf, &buflen));
        spaced = 0;

        /* Refresh interval. */
        t = ns_get32(rdata);  rdata += NS_INT32SZ;
        T(addstr("\t\t\t\t\t", 5, &buf, &buflen));
        T(len = ns_format_ttl(t, buf, buflen));
        addlen(len, &buf, &buflen);
        T(spaced = addtab(len, 16, spaced, &buf, &buflen));
        T(addstr("; refresh\n", 10, &buf, &buflen));
        spaced = 0;

        /* Retry interval. */
        t = ns_get32(rdata);  rdata += NS_INT32SZ;
        T(addstr("\t\t\t\t\t", 5, &buf, &buflen));
        T(len = ns_format_ttl(t, buf, buflen));
        addlen(len, &buf, &buflen);
        T(spaced = addtab(len, 16, spaced, &buf, &buflen));
        T(addstr("; retry\n", 8, &buf, &buflen));
        spaced = 0;

        /* Expiry. */
        t = ns_get32(rdata);  rdata += NS_INT32SZ;
        T(addstr("\t\t\t\t\t", 5, &buf, &buflen));
        T(len = ns_format_ttl(t, buf, buflen));
        addlen(len, &buf, &buflen);
        T(spaced = addtab(len, 16, spaced, &buf, &buflen));
        T(addstr("; expiry\n", 9, &buf, &buflen));
        spaced = 0;

        /* Minimum TTL. */
        t = ns_get32(rdata);  rdata += NS_INT32SZ;
        T(addstr("\t\t\t\t\t", 5, &buf, &buflen));
        T(len = ns_format_ttl(t, buf, buflen));
        addlen(len, &buf, &buflen);
        T(addstr(" )", 2, &buf, &buflen));
        T(spaced = addtab(len, 16, spaced, &buf, &buflen));
        T(addstr("; minimum\n", 10, &buf, &buflen));

        break;
        }

    case ns_t_mx:
    case ns_t_afsdb:
    case ns_t_rt:
    case ns_t_kx: {
        u_int t;

        if (rdlen < (size_t)NS_INT16SZ)
            goto formerr;

        /* Priority. */
        t = ns_get16(rdata);
        rdata += NS_INT16SZ;
        len = SPRINTF((tmp, "%u ", t));
        T(addstr(tmp, len, &buf, &buflen));

        /* Target. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));

        break;
        }

    case ns_t_px: {
        u_int t;

        if (rdlen < (size_t)NS_INT16SZ)
            goto formerr;

        /* Priority. */
        t = ns_get16(rdata);
        rdata += NS_INT16SZ;
        len = SPRINTF((tmp, "%u ", t));
        T(addstr(tmp, len, &buf, &buflen));

        /* Name1. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
        T(addstr(" ", 1, &buf, &buflen));

        /* Name2. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));

        break;
        }

    case ns_t_x25:
        T(len = charstr(rdata, edata, &buf, &buflen));
        if (len == 0)
            goto formerr;
        rdata += len;
        break;

    case ns_t_txt:
    case ns_t_spf:
        while (rdata < edata) {
            T(len = charstr(rdata, edata, &buf, &buflen));
            if (len == 0)
                goto formerr;
            rdata += len;
            if (rdata < edata)
                T(addstr(" ", 1, &buf, &buflen));
        }
        break;

    case ns_t_nsap: {
        char t[2+255*3];

        (void) inet_nsap_ntoa(rdlen, rdata, t);
        T(addstr(t, strlen(t), &buf, &buflen));
        break;
        }

    case ns_t_aaaa:
        if (rdlen != (size_t)NS_IN6ADDRSZ)
            goto formerr;
        (void) inet_ntop(AF_INET6, rdata, buf, buflen);
        addlen(strlen(buf), &buf, &buflen);
        break;

    case ns_t_loc: {
        char t[255];

        /* XXX protocol format checking? */
        (void) loc_ntoa(rdata, t);
        T(addstr(t, strlen(t), &buf, &buflen));
        break;
        }

    case ns_t_naptr: {
        u_int order, preference;
        char t[50];

        if (rdlen < 2U*NS_INT16SZ)
            goto formerr;

        /* Order, Precedence. */
        order = ns_get16(rdata);    rdata += NS_INT16SZ;
        preference = ns_get16(rdata);   rdata += NS_INT16SZ;
        len = SPRINTF((t, "%u %u ", order, preference));
        T(addstr(t, len, &buf, &buflen));

        /* Flags. */
        T(len = charstr(rdata, edata, &buf, &buflen));
        if (len == 0)
            goto formerr;
        rdata += len;
        T(addstr(" ", 1, &buf, &buflen));

        /* Service. */
        T(len = charstr(rdata, edata, &buf, &buflen));
        if (len == 0)
            goto formerr;
        rdata += len;
        T(addstr(" ", 1, &buf, &buflen));

        /* Regexp. */
        T(len = charstr(rdata, edata, &buf, &buflen));
        if (len < 0)
            return (-1);
        if (len == 0)
            goto formerr;
        rdata += len;
        T(addstr(" ", 1, &buf, &buflen));

        /* Server. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
        break;
        }

    case ns_t_srv: {
        u_int priority, weight, port;
        char t[50];

        if (rdlen < 3U*NS_INT16SZ)
            goto formerr;

        /* Priority, Weight, Port. */
        priority = ns_get16(rdata);  rdata += NS_INT16SZ;
        weight   = ns_get16(rdata);  rdata += NS_INT16SZ;
        port     = ns_get16(rdata);  rdata += NS_INT16SZ;
        len = SPRINTF((t, "%u %u %u ", priority, weight, port));
        T(addstr(t, len, &buf, &buflen));

        /* Server. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
        break;
        }

    case ns_t_minfo:
    case ns_t_rp:
        /* Name1. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
        T(addstr(" ", 1, &buf, &buflen));

        /* Name2. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));

        break;

    case ns_t_wks: {
        int n, lcnt;

        if (rdlen < 1U + NS_INT32SZ)
            goto formerr;

        /* Address. */
        (void) inet_ntop(AF_INET, rdata, buf, buflen);
        addlen(strlen(buf), &buf, &buflen);
        rdata += NS_INADDRSZ;

        /* Protocol. */
        len = SPRINTF((tmp, " %u ( ", *rdata));
        T(addstr(tmp, len, &buf, &buflen));
        rdata += NS_INT8SZ;

        /* Bit map. */
        n = 0;
        lcnt = 0;
        while (rdata < edata) {
            u_int c = *rdata++;
            do {
                if (c & 0200) {
                    if (lcnt == 0) {
                        T(addstr("\n\t\t\t\t", 5,
                             &buf, &buflen));
                        lcnt = 10;
                        spaced = 0;
                    }
                    len = SPRINTF((tmp, "%d ", n));
                    T(addstr(tmp, len, &buf, &buflen));
                    lcnt--;
                }
                c <<= 1;
            } while (++n & 07);
        }
        T(addstr(")", 1, &buf, &buflen));

        break;
        }

    case ns_t_key:
    case ns_t_dnskey: {
        char base64_key[NS_MD5RSA_MAX_BASE64];
        u_int keyflags, protocol, algorithm, key_id;
        const char *leader;
        int n;

        if (rdlen < 0U + NS_INT16SZ + NS_INT8SZ + NS_INT8SZ)
            goto formerr;

        /* Key flags, Protocol, Algorithm. */
        key_id = dst_s_dns_key_id(rdata, edata-rdata);
        keyflags = ns_get16(rdata);  rdata += NS_INT16SZ;
        protocol = *rdata++;
        algorithm = *rdata++;
        len = SPRINTF((tmp, "0x%04x %u %u",
                   keyflags, protocol, algorithm));
        T(addstr(tmp, len, &buf, &buflen));

        /* Public key data. */
        len = b64_ntop(rdata, edata - rdata,
                   base64_key, sizeof base64_key);
        if (len < 0)
            goto formerr;
        if (len > 15) {
            T(addstr(" (", 2, &buf, &buflen));
            leader = "\n\t\t";
            spaced = 0;
        } else
            leader = " ";
        for (n = 0; n < len; n += 48) {
            T(addstr(leader, strlen(leader), &buf, &buflen));
            T(addstr(base64_key + n, MIN(len - n, 48),
                 &buf, &buflen));
        }
        if (len > 15)
            T(addstr(" )", 2, &buf, &buflen));
        n = SPRINTF((tmp, " ; key_tag= %u", key_id));
        T(addstr(tmp, n, &buf, &buflen));

        break;
        }

    case ns_t_sig:
    case ns_t_rrsig: {
        char base64_key[NS_MD5RSA_MAX_BASE64];
        u_int type, algorithm, labels, footprint;
        const char *leader;
        u_long t;
        int n;

        if (rdlen < 22U)
            goto formerr;

        /* Type covered, Algorithm, Label count, Original TTL. */
        type = ns_get16(rdata);  rdata += NS_INT16SZ;
        algorithm = *rdata++;
        labels = *rdata++;
        t = ns_get32(rdata);  rdata += NS_INT32SZ;
        len = SPRINTF((tmp, "%s %d %d %lu ",
                   p_type(type), algorithm, labels, t));
        T(addstr(tmp, len, &buf, &buflen));
        if (labels > (u_int)dn_count_labels(name))
            goto formerr;

        /* Signature expiry. */
        t = ns_get32(rdata);  rdata += NS_INT32SZ;
        len = SPRINTF((tmp, "%s ", p_secstodate(t)));
        T(addstr(tmp, len, &buf, &buflen));

        /* Time signed. */
        t = ns_get32(rdata);  rdata += NS_INT32SZ;
        len = SPRINTF((tmp, "%s ", p_secstodate(t)));
        T(addstr(tmp, len, &buf, &buflen));

        /* Signature Footprint. */
        footprint = ns_get16(rdata);  rdata += NS_INT16SZ;
        len = SPRINTF((tmp, "%u ", footprint));
        T(addstr(tmp, len, &buf, &buflen));

        /* Signer's name. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));

        /* Signature. */
        len = b64_ntop(rdata, edata - rdata,
                   base64_key, sizeof base64_key);
        if (len > 15) {
            T(addstr(" (", 2, &buf, &buflen));
            leader = "\n\t\t";
            spaced = 0;
        } else
            leader = " ";
        if (len < 0)
            goto formerr;
        for (n = 0; n < len; n += 48) {
            T(addstr(leader, strlen(leader), &buf, &buflen));
            T(addstr(base64_key + n, MIN(len - n, 48),
                 &buf, &buflen));
        }
        if (len > 15)
            T(addstr(" )", 2, &buf, &buflen));
        break;
        }

    case ns_t_nxt: {
        int n, c;

        /* Next domain name. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));

        /* Type bit map. */
        n = edata - rdata;
        for (c = 0; c < n*8; c++)
            if (NS_NXT_BIT_ISSET(c, rdata)) {
                len = SPRINTF((tmp, " %s", p_type(c)));
                T(addstr(tmp, len, &buf, &buflen));
            }
        break;
        }

    case ns_t_cert: {
        u_int c_type, key_tag, alg;
        int n;
        unsigned int siz;
        char base64_cert[8192], tmp[40];
        const char *leader;

        c_type  = ns_get16(rdata); rdata += NS_INT16SZ;
        key_tag = ns_get16(rdata); rdata += NS_INT16SZ;
        alg = (u_int) *rdata++;

        len = SPRINTF((tmp, "%d %d %d ", c_type, key_tag, alg));
        T(addstr(tmp, len, &buf, &buflen));
        siz = (edata-rdata)*4/3 + 4; /* "+4" accounts for trailing \0 */
        if (siz > sizeof(base64_cert) * 3/4) {
            const char *str = "record too long to print";
            T(addstr(str, strlen(str), &buf, &buflen));
        }
        else {
            len = b64_ntop(rdata, edata-rdata, base64_cert, siz);

            if (len < 0)
                goto formerr;
            else if (len > 15) {
                T(addstr(" (", 2, &buf, &buflen));
                leader = "\n\t\t";
                spaced = 0;
            }
            else
                leader = " ";

            for (n = 0; n < len; n += 48) {
                T(addstr(leader, strlen(leader),
                     &buf, &buflen));
                T(addstr(base64_cert + n, MIN(len - n, 48),
                     &buf, &buflen));
            }
            if (len > 15)
                T(addstr(" )", 2, &buf, &buflen));
        }
        break;
        }

    case ns_t_tkey: {
        /* KJD - need to complete this */
        u_long t;
        int mode, err, keysize;

        /* Algorithm name. */
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
        T(addstr(" ", 1, &buf, &buflen));

        /* Inception. */
        t = ns_get32(rdata);  rdata += NS_INT32SZ;
        len = SPRINTF((tmp, "%s ", p_secstodate(t)));
        T(addstr(tmp, len, &buf, &buflen));

        /* Experation. */
        t = ns_get32(rdata);  rdata += NS_INT32SZ;
        len = SPRINTF((tmp, "%s ", p_secstodate(t)));
        T(addstr(tmp, len, &buf, &buflen));

        /* Mode , Error, Key Size. */
        /* Priority, Weight, Port. */
        mode = ns_get16(rdata);  rdata += NS_INT16SZ;
        err  = ns_get16(rdata);  rdata += NS_INT16SZ;
        keysize  = ns_get16(rdata);  rdata += NS_INT16SZ;
        len = SPRINTF((tmp, "%u %u %u ", mode, err, keysize));
        T(addstr(tmp, len, &buf, &buflen));

        /* XXX need to dump key, print otherdata length & other data */
        break;
        }

    case ns_t_tsig: {
        /* BEW - need to complete this */
        int n;

        T(len = addname(msg, msglen, &rdata, origin, &buf, &buflen));
        T(addstr(" ", 1, &buf, &buflen));
        rdata += 8; /*%< time */
        n = ns_get16(rdata); rdata += INT16SZ;
        rdata += n; /*%< sig */
        n = ns_get16(rdata); rdata += INT16SZ; /*%< original id */
        sprintf(buf, "%d", ns_get16(rdata));
        rdata += INT16SZ;
        addlen(strlen(buf), &buf, &buflen);
        break;
        }

    case ns_t_a6: {
        struct in6_addr a;
        int pbyte, pbit;

        /* prefix length */
        if (rdlen == 0U) goto formerr;
        len = SPRINTF((tmp, "%d ", *rdata));
        T(addstr(tmp, len, &buf, &buflen));
        pbit = *rdata;
        if (pbit > 128) goto formerr;
        pbyte = (pbit & ~7) / 8;
        rdata++;

        /* address suffix: provided only when prefix len != 128 */
        if (pbit < 128) {
            if (rdata + pbyte >= edata) goto formerr;
            memset(&a, 0, sizeof(a));
            memcpy(&a.s6_addr[pbyte], rdata, sizeof(a) - pbyte);
            (void) inet_ntop(AF_INET6, &a, buf, buflen);
            addlen(strlen(buf), &buf, &buflen);
            rdata += sizeof(a) - pbyte;
        }

        /* prefix name: provided only when prefix len > 0 */
        if (pbit == 0)
            break;
        if (rdata >= edata) goto formerr;
        T(addstr(" ", 1, &buf, &buflen));
        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));

        break;
        }

    case ns_t_opt: {
        len = SPRINTF((tmp, "%u bytes", class));
        T(addstr(tmp, len, &buf, &buflen));
        break;
        }

    case ns_t_ds:
    case ns_t_dlv:
    case ns_t_sshfp: {
        u_int t;

        if (type == ns_t_ds || type == ns_t_dlv) {
            if (rdlen < 4U) goto formerr;
            t = ns_get16(rdata);
            rdata += NS_INT16SZ;
            len = SPRINTF((tmp, "%u ", t));
            T(addstr(tmp, len, &buf, &buflen));
        } else
            if (rdlen < 2U) goto formerr;

        len = SPRINTF((tmp, "%u ", *rdata));
        T(addstr(tmp, len, &buf, &buflen));
        rdata++;

        len = SPRINTF((tmp, "%u ", *rdata));
        T(addstr(tmp, len, &buf, &buflen));
        rdata++;

        while (rdata < edata) {
            len = SPRINTF((tmp, "%02X", *rdata));
            T(addstr(tmp, len, &buf, &buflen));
            rdata++;
        }
        break;
        }

    case ns_t_nsec3:
    case ns_t_nsec3param: {
        u_int t, w, l, j, k, c;

        len = SPRINTF((tmp, "%u ", *rdata));
        T(addstr(tmp, len, &buf, &buflen));
        rdata++;

        len = SPRINTF((tmp, "%u ", *rdata));
        T(addstr(tmp, len, &buf, &buflen));
        rdata++;

        t = ns_get16(rdata);
        rdata += NS_INT16SZ;
        len = SPRINTF((tmp, "%u ", t));
        T(addstr(tmp, len, &buf, &buflen));

        t = *rdata++;
        if (t == 0) {
            T(addstr("-", 1, &buf, &buflen));
        } else {
            while (t-- > 0) {
                len = SPRINTF((tmp, "%02X", *rdata));
                T(addstr(tmp, len, &buf, &buflen));
                rdata++;
            }
        }
        if (type == ns_t_nsec3param)
            break;
        T(addstr(" ", 1, &buf, &buflen));

        t = *rdata++;
        while (t > 0) {
            switch (t) {
            case 1:
                tmp[0] = base32hex[((rdata[0]>>3)&0x1f)];
                tmp[1] = base32hex[((rdata[0]<<2)&0x1c)];
                tmp[2] = tmp[3] = tmp[4] = '=';
                tmp[5] = tmp[6] = tmp[7] = '=';
                break;
            case 2:
                tmp[0] = base32hex[((rdata[0]>>3)&0x1f)];
                tmp[1] = base32hex[((rdata[0]<<2)&0x1c)|
                           ((rdata[1]>>6)&0x03)];
                tmp[2] = base32hex[((rdata[1]>>1)&0x1f)];
                tmp[3] = base32hex[((rdata[1]<<4)&0x10)];
                tmp[4] = tmp[5] = tmp[6] = tmp[7] = '=';
                break;
            case 3:
                tmp[0] = base32hex[((rdata[0]>>3)&0x1f)];
                tmp[1] = base32hex[((rdata[0]<<2)&0x1c)|
                           ((rdata[1]>>6)&0x03)];
                tmp[2] = base32hex[((rdata[1]>>1)&0x1f)];
                tmp[3] = base32hex[((rdata[1]<<4)&0x10)|
                           ((rdata[2]>>4)&0x0f)];
                tmp[4] = base32hex[((rdata[2]<<1)&0x1e)];
                tmp[5] = tmp[6] = tmp[7] = '=';
                break;
            case 4:
                tmp[0] = base32hex[((rdata[0]>>3)&0x1f)];
                tmp[1] = base32hex[((rdata[0]<<2)&0x1c)|
                           ((rdata[1]>>6)&0x03)];
                tmp[2] = base32hex[((rdata[1]>>1)&0x1f)];
                tmp[3] = base32hex[((rdata[1]<<4)&0x10)|
                           ((rdata[2]>>4)&0x0f)];
                tmp[4] = base32hex[((rdata[2]<<1)&0x1e)|
                           ((rdata[3]>>7)&0x01)];
                tmp[5] = base32hex[((rdata[3]>>2)&0x1f)];
                tmp[6] = base32hex[(rdata[3]<<3)&0x18];
                tmp[7] = '=';
                break;
            default:
                tmp[0] = base32hex[((rdata[0]>>3)&0x1f)];
                tmp[1] = base32hex[((rdata[0]<<2)&0x1c)|
                           ((rdata[1]>>6)&0x03)];
                tmp[2] = base32hex[((rdata[1]>>1)&0x1f)];
                tmp[3] = base32hex[((rdata[1]<<4)&0x10)|
                           ((rdata[2]>>4)&0x0f)];
                tmp[4] = base32hex[((rdata[2]<<1)&0x1e)|
                           ((rdata[3]>>7)&0x01)];
                tmp[5] = base32hex[((rdata[3]>>2)&0x1f)];
                tmp[6] = base32hex[((rdata[3]<<3)&0x18)|
                           ((rdata[4]>>5)&0x07)];
                tmp[7] = base32hex[(rdata[4]&0x1f)];
                break;
            }
            T(addstr(tmp, 8, &buf, &buflen));
            if (t >= 5) {
                rdata += 5;
                t -= 5;
            } else {
                rdata += t;
                t -= t;
            }
        }

        while (rdata < edata) {
            w = *rdata++;
            l = *rdata++;
            for (j = 0; j < l; j++) {
                if (rdata[j] == 0)
                    continue;
                for (k = 0; k < 8; k++) {
                    if ((rdata[j] & (0x80 >> k)) == 0)
                        continue;
                    c = w * 256 + j * 8 + k;
                    len = SPRINTF((tmp, " %s", p_type(c)));
                    T(addstr(tmp, len, &buf, &buflen));
                }
            }
            rdata += l;
        }
        break;
        }

    case ns_t_nsec: {
        u_int w, l, j, k, c;

        T(addname(msg, msglen, &rdata, origin, &buf, &buflen));

        while (rdata < edata) {
            w = *rdata++;
            l = *rdata++;
            for (j = 0; j < l; j++) {
                if (rdata[j] == 0)
                    continue;
                for (k = 0; k < 8; k++) {
                    if ((rdata[j] & (0x80 >> k)) == 0)
                        continue;
                    c = w * 256 + j * 8 + k;
                    len = SPRINTF((tmp, " %s", p_type(c)));
                    T(addstr(tmp, len, &buf, &buflen));
                }
            }
            rdata += l;
        }
        break;
        }

    case ns_t_dhcid: {
        int n;
        unsigned int siz;
        char base64_dhcid[8192];
        const char *leader;

        siz = (edata-rdata)*4/3 + 4; /* "+4" accounts for trailing \0 */
        if (siz > sizeof(base64_dhcid) * 3/4) {
            const char *str = "record too long to print";
            T(addstr(str, strlen(str), &buf, &buflen));
        } else {
            len = b64_ntop(rdata, edata-rdata, base64_dhcid, siz);

            if (len < 0)
                goto formerr;

            else if (len > 15) {
                T(addstr(" (", 2, &buf, &buflen));
                leader = "\n\t\t";
                spaced = 0;
            }
            else
                leader = " ";

            for (n = 0; n < len; n += 48) {
                T(addstr(leader, strlen(leader),
                     &buf, &buflen));
                T(addstr(base64_dhcid + n, MIN(len - n, 48),
                     &buf, &buflen));
            }
            if (len > 15)
                T(addstr(" )", 2, &buf, &buflen));
        }
    }

    case ns_t_ipseckey: {
        int n;
        unsigned int siz;
        char base64_key[8192];
        const char *leader;

        if (rdlen < 2)
            goto formerr;

        switch (rdata[1]) {
        case 0:
        case 3:
            if (rdlen < 3)
                goto formerr;
            break;
        case 1:
            if (rdlen < 7)
                goto formerr;
            break;
        case 2:
            if (rdlen < 19)
                goto formerr;
            break;
        default:
            comment = "unknown IPSECKEY gateway type";
            goto hexify;
        }

        len = SPRINTF((tmp, "%u ", *rdata));
        T(addstr(tmp, len, &buf, &buflen));
        rdata++;

        len = SPRINTF((tmp, "%u ", *rdata));
        T(addstr(tmp, len, &buf, &buflen));
        rdata++;

        len = SPRINTF((tmp, "%u ", *rdata));
        T(addstr(tmp, len, &buf, &buflen));
        rdata++;

        switch (rdata[-2]) {
        case 0:
            T(addstr(".", 1, &buf, &buflen));
            break;
        case 1:
            (void) inet_ntop(AF_INET, rdata, buf, buflen);
            addlen(strlen(buf), &buf, &buflen);
            rdata += 4;
            break;
        case 2:
            (void) inet_ntop(AF_INET6, rdata, buf, buflen);
            addlen(strlen(buf), &buf, &buflen);
            rdata += 16;
            break;
        case 3:
            T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
            break;
        }

        if (rdata >= edata)
            break;

        siz = (edata-rdata)*4/3 + 4; /* "+4" accounts for trailing \0 */
        if (siz > sizeof(base64_key) * 3/4) {
            const char *str = "record too long to print";
            T(addstr(str, strlen(str), &buf, &buflen));
        } else {
            len = b64_ntop(rdata, edata-rdata, base64_key, siz);

            if (len < 0)
                goto formerr;

            else if (len > 15) {
                T(addstr(" (", 2, &buf, &buflen));
                leader = "\n\t\t";
                spaced = 0;
            }
            else
                leader = " ";

            for (n = 0; n < len; n += 48) {
                T(addstr(leader, strlen(leader),
                     &buf, &buflen));
                T(addstr(base64_key + n, MIN(len - n, 48),
                     &buf, &buflen));
            }
            if (len > 15)
                T(addstr(" )", 2, &buf, &buflen));
        }
    }

    case ns_t_hip: {
        unsigned int i, hip_len, algorithm, key_len;
        char base64_key[NS_MD5RSA_MAX_BASE64];
        unsigned int siz;
        const char *leader = "\n\t\t\t\t\t";

        hip_len = *rdata++;
        algorithm = *rdata++;
        key_len = ns_get16(rdata);
        rdata += NS_INT16SZ;

        siz = key_len*4/3 + 4; /* "+4" accounts for trailing \0 */
        if (siz > sizeof(base64_key) * 3/4) {
            const char *str = "record too long to print";
            T(addstr(str, strlen(str), &buf, &buflen));
        } else {
            len = sprintf(tmp, "( %u ", algorithm);
            T(addstr(tmp, len, &buf, &buflen));

            for (i = 0; i < hip_len; i++) {
                len = sprintf(tmp, "%02X", *rdata);
                T(addstr(tmp, len, &buf, &buflen));
                rdata++;
            }
            T(addstr(leader, strlen(leader), &buf, &buflen));

            len = b64_ntop(rdata, key_len, base64_key, siz);
            if (len < 0)
                goto formerr;

            T(addstr(base64_key, len, &buf, &buflen));

            rdata += key_len;
            while (rdata < edata) {
                T(addstr(leader, strlen(leader), &buf, &buflen));
                T(addname(msg, msglen, &rdata, origin,
                      &buf, &buflen));
            }
            T(addstr(" )", 2, &buf, &buflen));
        }
        break;
    }

    default:
        comment = "unknown RR type";
        goto hexify;
    }
    return (buf - obuf);
 formerr:
    comment = "RR format error";
 hexify: {
    int n, m;
    char *p;

    len = SPRINTF((tmp, "\\# %u%s\t; %s", (unsigned)(edata - rdata),
               rdlen != 0U ? " (" : "", comment));
    T(addstr(tmp, len, &buf, &buflen));
    while (rdata < edata) {
        p = tmp;
        p += SPRINTF((p, "\n\t"));
        spaced = 0;
        n = MIN(16, edata - rdata);
        for (m = 0; m < n; m++)
            p += SPRINTF((p, "%02x ", rdata[m]));
        T(addstr(tmp, p - tmp, &buf, &buflen));
        if (n < 16) {
            T(addstr(")", 1, &buf, &buflen));
            T(addtab(p - tmp + 1, 48, spaced, &buf, &buflen));
        }
        p = tmp;
        p += SPRINTF((p, "; "));
        for (m = 0; m < n; m++)
            *p++ = (isascii(rdata[m]) && isprint(rdata[m]))
                ? rdata[m]
                : '.';
        T(addstr(tmp, p - tmp, &buf, &buflen));
        rdata += n;
    }
    return (buf - obuf);
    }
}

/* Private. */

/*%
 * size_t
 * prune_origin(name, origin)
 *  Find out if the name is at or under the current origin.
 * return:
 *  Number of characters in name before start of origin,
 *  or length of name if origin does not match.
 * notes:
 *  This function should share code with samedomain().
 */
static size_t
prune_origin(const char *name, const char *origin) {
    const char *oname = name;

    while (*name != '\0') {
        if (origin != NULL && ns_samename(name, origin) == 1)
            return (name - oname - (name > oname));
        while (*name != '\0') {
            if (*name == '\\') {
                name++;
                /* XXX need to handle \nnn form. */
                if (*name == '\0')
                    break;
            } else if (*name == '.') {
                name++;
                break;
            }
            name++;
        }
    }
    return (name - oname);
}

/*%
 * int
 * charstr(rdata, edata, buf, buflen)
 *  Format a <character-string> into the presentation buffer.
 * return:
 *  Number of rdata octets consumed
 *  0 for protocol format error
 *  -1 for output buffer error
 * side effects:
 *  buffer is advanced on success.
 */
static int
charstr(const u_char *rdata, const u_char *edata, char **buf, size_t *buflen) {
    const u_char *odata = rdata;
    size_t save_buflen = *buflen;
    char *save_buf = *buf;

    if (addstr("\"", 1, buf, buflen) < 0)
        goto enospc;
    if (rdata < edata) {
        int n = *rdata;

        if (rdata + 1 + n <= edata) {
            rdata++;
            while (n-- > 0) {
                if (strchr("\n\"\\", *rdata) != NULL)
                    if (addstr("\\", 1, buf, buflen) < 0)
                        goto enospc;
                if (addstr((const char *)rdata, 1,
                       buf, buflen) < 0)
                    goto enospc;
                rdata++;
            }
        }
    }
    if (addstr("\"", 1, buf, buflen) < 0)
        goto enospc;
    return (rdata - odata);
 enospc:
    errno = ENOSPC;
    *buf = save_buf;
    *buflen = save_buflen;
    return (-1);
}

static int
addname(const u_char *msg, size_t msglen,
    const u_char **pp, const char *origin,
    char **buf, size_t *buflen)
{
    size_t newlen, save_buflen = *buflen;
    char *save_buf = *buf;
    int n;

    n = dn_expand(msg, msg + msglen, *pp, *buf, *buflen);
    if (n < 0)
        goto enospc;    /*%< Guess. */
    newlen = prune_origin(*buf, origin);
    if (**buf == '\0') {
        goto root;
    } else if (newlen == 0U) {
        /* Use "@" instead of name. */
        if (newlen + 2 > *buflen)
            goto enospc;        /* No room for "@\0". */
        (*buf)[newlen++] = '@';
        (*buf)[newlen] = '\0';
    } else {
        if (((origin == NULL || origin[0] == '\0') ||
            (origin[0] != '.' && origin[1] != '\0' &&
            (*buf)[newlen] == '\0')) && (*buf)[newlen - 1] != '.') {
            /* No trailing dot. */
 root:
            if (newlen + 2 > *buflen)
                goto enospc;    /* No room for ".\0". */
            (*buf)[newlen++] = '.';
            (*buf)[newlen] = '\0';
        }
    }
    *pp += n;
    addlen(newlen, buf, buflen);
    **buf = '\0';
    return (newlen);
 enospc:
    errno = ENOSPC;
    *buf = save_buf;
    *buflen = save_buflen;
    return (-1);
}

static void
addlen(size_t len, char **buf, size_t *buflen) {
    INSIST(len <= *buflen);
    *buf += len;
    *buflen -= len;
}

static int
addstr(const char *src, size_t len, char **buf, size_t *buflen) {
    if (len >= *buflen) {
        errno = ENOSPC;
        return (-1);
    }
    memcpy(*buf, src, len);
    addlen(len, buf, buflen);
    **buf = '\0';
    return (0);
}

static int
addtab(size_t len, size_t target, int spaced, char **buf, size_t *buflen) {
    size_t save_buflen = *buflen;
    char *save_buf = *buf;
    int t;

    if (spaced || len >= target - 1) {
        T(addstr("  ", 2, buf, buflen));
        spaced = 1;
    } else {
        for (t = (target - len - 1) / 8; t >= 0; t--)
            if (addstr("\t", 1, buf, buflen) < 0) {
                *buflen = save_buflen;
                *buf = save_buf;
                return (-1);
            }
        spaced = 0;
    }
    return (spaced);
}

/*! \file */