Subversion Repositories or1k

/*

 * Copyright (c) 1996 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS

 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE

 * CONSORTIUM 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.

 */

#if !defined(__rtems__)

#if !defined(LINT) && !defined(CODECENTER)

static char rcsid[] = "$Id: ns_parse.c,v 1.2 2001-09-27 12:01:53 chris Exp $";

#endif /* not lint */

#endif /* not rtems */

#include <sys/types.h>

#include <netinet/in.h>

#include <arpa/nameser.h>

#include <errno.h>

#include <resolv.h>

#include <string.h>

/* These need to be in the same order as the nres.h:ns_flag enum. */

struct _ns_flagdata _ns_flagdata[16] = {

        { 0x8000, 15 },         /* qr. */

        { 0x7800, 11 },         /* opcode. */

        { 0x0400, 10 },         /* aa. */

        { 0x0200, 9 },          /* tc. */

        { 0x0100, 8 },          /* rd. */

        { 0x0080, 7 },          /* ra. */

        { 0x0040, 6 },          /* z. */

        { 0x0020, 5 },          /* ad. */

        { 0x0010, 4 },          /* cd. */

        { 0x000f, 0 },           /* rcode. */

        { 0x0000, 0 },           /* expansion (1/6). */

        { 0x0000, 0 },           /* expansion (2/6). */

        { 0x0000, 0 },           /* expansion (3/6). */

        { 0x0000, 0 },           /* expansion (4/6). */

        { 0x0000, 0 },           /* expansion (5/6). */

        { 0x0000, 0 },           /* expansion (6/6). */

};

static int

skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) {

        const u_char *optr = ptr;

        for ((void)NULL; count > 0; count--) {

                int b, rdlength;

                b = dn_skipname(ptr, eom);

                if (b < 0)

                        goto emsgsize;

                ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;

                if (section != ns_s_qd) {

                        if (ptr + NS_INT32SZ > eom)

                                goto emsgsize;

                        ptr += NS_INT32SZ/*TTL*/;

                        if (ptr + NS_INT16SZ > eom)

                                goto emsgsize;

                        NS_GET16(rdlength, ptr);

                        ptr += rdlength/*RData*/;

                }

        }

        if (ptr > eom)

                goto emsgsize;

        return (ptr - optr);

 emsgsize:

        errno = EMSGSIZE;

        return (-1);

}

int

ns_initparse(const u_char *msg, int msglen, ns_msg *handle) {

        const u_char *eom = msg + msglen;

        int i;

        memset(handle, 0x5e, sizeof *handle);

        handle->_msg = msg;

        handle->_eom = eom;

        if (msg + NS_INT16SZ > eom)

                goto emsgsize;

        NS_GET16(handle->_id, msg);

        if (msg + NS_INT16SZ > eom)

                goto emsgsize;

        NS_GET16(handle->_flags, msg);

        for (i = 0; i < ns_s_max; i++) {

                if (msg + NS_INT16SZ > eom)

                        goto emsgsize;

                NS_GET16(handle->_counts[i], msg);

        }

        for (i = 0; i < ns_s_max; i++)

                if (handle->_counts[i] == 0)

                        handle->_sections[i] = NULL;

                else {

                        int b = skiprr(msg, eom, (ns_sect)i,

                                       handle->_counts[i]);

                        if (b < 0)

                                return (-1);

                        handle->_sections[i] = msg;

                        msg += b;

                }

        if (msg != eom)

                goto emsgsize;

        handle->_sect = ns_s_max;

        handle->_rrnum = -1;

        handle->_ptr = NULL;

        return (0);

 emsgsize:

        errno = EMSGSIZE;

        return (-1);

}

int

ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) {

        int b;

        /* Make section right. */

        if (section < 0 || section >= ns_s_max)

                goto enodev;

        if ((int)section != (int)handle->_sect) {

                handle->_sect = section;

                handle->_rrnum = 0;

                handle->_ptr = handle->_sections[(int)section];

        }

        /* Make rrnum right. */

        if (rrnum == -1)

                rrnum = handle->_rrnum;

        if (rrnum < 0 || rrnum >= handle->_counts[(int)section])

                goto enodev;

        if (rrnum < handle->_rrnum) {

                handle->_rrnum = 0;

                handle->_ptr = handle->_sections[(int)section];

        }

        b = skiprr(handle->_msg, handle->_eom, section,

                   rrnum - handle->_rrnum);

        if (b < 0)

                return (-1);

        handle->_ptr += b;

        handle->_rrnum = rrnum;

        /* Do the parse. */

        b = dn_expand(handle->_msg, handle->_eom,

                      handle->_ptr, rr->name, NS_MAXDNAME);

        if (b < 0)

                return (-1);

        handle->_ptr += b;

        if (handle->_ptr + NS_INT16SZ > handle->_eom)

                goto emsgsize;

        NS_GET16(rr->type, handle->_ptr);

        if (handle->_ptr + NS_INT16SZ > handle->_eom)

                goto emsgsize;

        NS_GET16(rr->class, handle->_ptr);

        if (section == ns_s_qd) {

                rr->ttl = 0;

                rr->rdlength = 0;

                rr->rdata = NULL;

        } else {

                if (handle->_ptr + NS_INT32SZ > handle->_eom)

                        goto emsgsize;

                NS_GET32(rr->ttl, handle->_ptr);

                if (handle->_ptr + NS_INT16SZ > handle->_eom)

                        goto emsgsize;

                NS_GET16(rr->rdlength, handle->_ptr);

                if (handle->_ptr + rr->rdlength > handle->_eom)

                        goto emsgsize;

                rr->rdata = handle->_ptr;

                handle->_ptr += rr->rdlength;

        }

        handle->_rrnum++;

        /* All done. */

        return (0);

 enodev:

        errno = ENODEV;

        return (-1);

 emsgsize:

        errno = EMSGSIZE;

        return (-1);

}