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res_mkquery.c revision 1.9
      1 /*	$NetBSD: res_mkquery.c,v 1.9 2008/06/21 20:41:48 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1985, 1993
      5  *    The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  * 	This product includes software developed by the University of
     18  * 	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 /*
     37  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
     38  *
     39  * Permission to use, copy, modify, and distribute this software for any
     40  * purpose with or without fee is hereby granted, provided that the above
     41  * copyright notice and this permission notice appear in all copies, and that
     42  * the name of Digital Equipment Corporation not be used in advertising or
     43  * publicity pertaining to distribution of the document or software without
     44  * specific, written prior permission.
     45  *
     46  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
     47  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
     48  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
     49  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
     50  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
     51  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
     52  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
     53  * SOFTWARE.
     54  */
     55 
     56 /*
     57  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
     58  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
     59  *
     60  * Permission to use, copy, modify, and distribute this software for any
     61  * purpose with or without fee is hereby granted, provided that the above
     62  * copyright notice and this permission notice appear in all copies.
     63  *
     64  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
     65  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     66  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
     67  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     68  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     69  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
     70  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     71  */
     72 
     73 #include <sys/cdefs.h>
     74 #if defined(LIBC_SCCS) && !defined(lint)
     75 #ifdef notdef
     76 static const char sccsid[] = "@(#)res_mkquery.c	8.1 (Berkeley) 6/4/93";
     77 static const char rcsid[] = "Id: res_mkquery.c,v 1.6.672.1 2008/04/03 02:12:21 marka Exp";
     78 #else
     79 __RCSID("$NetBSD: res_mkquery.c,v 1.9 2008/06/21 20:41:48 christos Exp $");
     80 #endif
     81 #endif /* LIBC_SCCS and not lint */
     82 
     83 #include "port_before.h"
     84 
     85 #include "namespace.h"
     86 #include <sys/types.h>
     87 #include <sys/param.h>
     88 #include <netinet/in.h>
     89 #include <arpa/nameser.h>
     90 #include <netdb.h>
     91 #include <resolv.h>
     92 #include <stdio.h>
     93 #include <string.h>
     94 #include "port_after.h"
     95 
     96 #if 0
     97 #ifdef __weak_alias
     98 __weak_alias(res_nmkquery,_res_nmkquery)
     99 __weak_alias(res_nopt,_res_nopt)
    100 #endif
    101 #endif
    102 
    103 /* Options.  Leave them on. */
    104 #define DEBUG
    105 
    106 extern const char *_res_opcodes[];
    107 
    108 /*%
    109  * Form all types of queries.
    110  * Returns the size of the result or -1.
    111  */
    112 int
    113 res_nmkquery(res_state statp,
    114 	     int op,			/*!< opcode of query  */
    115 	     const char *dname,		/*!< domain name  */
    116 	     int class, int type,	/*!< class and type of query  */
    117 	     const u_char *data,	/*!< resource record data  */
    118 	     int datalen,		/*!< length of data  */
    119 	     const u_char *newrr_in,	/*!< new rr for modify or append  */
    120 	     u_char *buf,		/*!< buffer to put query  */
    121 	     int buflen)		/*!< size of buffer  */
    122 {
    123 	register HEADER *hp;
    124 	register u_char *cp, *ep;
    125 	register int n;
    126 	u_char *dnptrs[20], **dpp, **lastdnptr;
    127 
    128 	UNUSED(newrr_in);
    129 
    130 #ifdef DEBUG
    131 	if (statp->options & RES_DEBUG)
    132 		printf(";; res_nmkquery(%s, %s, %s, %s)\n",
    133 		       _res_opcodes[op], dname, p_class(class), p_type(type));
    134 #endif
    135 	/*
    136 	 * Initialize header fields.
    137 	 */
    138 	if ((buf == NULL) || (buflen < HFIXEDSZ))
    139 		return (-1);
    140 	memset(buf, 0, HFIXEDSZ);
    141 	hp = (HEADER *)(void *)buf;
    142 	hp->id = htons(++statp->id);
    143 	hp->opcode = op;
    144 	hp->rd = (statp->options & RES_RECURSE) != 0U;
    145 	hp->rcode = NOERROR;
    146 	cp = buf + HFIXEDSZ;
    147 	ep = buf + buflen;
    148 	dpp = dnptrs;
    149 	*dpp++ = buf;
    150 	*dpp++ = NULL;
    151 	lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
    152 	/*
    153 	 * perform opcode specific processing
    154 	 */
    155 	switch (op) {
    156 	case QUERY:	/*FALLTHROUGH*/
    157 	case NS_NOTIFY_OP:
    158 		if (ep - cp < QFIXEDSZ)
    159 			return (-1);
    160 		if ((n = dn_comp(dname, cp, ep - cp - QFIXEDSZ, dnptrs,
    161 		    lastdnptr)) < 0)
    162 			return (-1);
    163 		cp += n;
    164 		ns_put16(type, cp);
    165 		cp += INT16SZ;
    166 		ns_put16(class, cp);
    167 		cp += INT16SZ;
    168 		hp->qdcount = htons(1);
    169 		if (op == QUERY || data == NULL)
    170 			break;
    171 		/*
    172 		 * Make an additional record for completion domain.
    173 		 */
    174 		if ((ep - cp) < RRFIXEDSZ)
    175 			return (-1);
    176 		n = dn_comp((const char *)data, cp, ep - cp - RRFIXEDSZ,
    177 			    dnptrs, lastdnptr);
    178 		if (n < 0)
    179 			return (-1);
    180 		cp += n;
    181 		ns_put16(T_NULL, cp);
    182 		cp += INT16SZ;
    183 		ns_put16(class, cp);
    184 		cp += INT16SZ;
    185 		ns_put32(0, cp);
    186 		cp += INT32SZ;
    187 		ns_put16(0, cp);
    188 		cp += INT16SZ;
    189 		hp->arcount = htons(1);
    190 		break;
    191 
    192 	case IQUERY:
    193 		/*
    194 		 * Initialize answer section
    195 		 */
    196 		if (ep - cp < 1 + RRFIXEDSZ + datalen)
    197 			return (-1);
    198 		*cp++ = '\0';	/*%< no domain name */
    199 		ns_put16(type, cp);
    200 		cp += INT16SZ;
    201 		ns_put16(class, cp);
    202 		cp += INT16SZ;
    203 		ns_put32(0, cp);
    204 		cp += INT32SZ;
    205 		ns_put16(datalen, cp);
    206 		cp += INT16SZ;
    207 		if (datalen) {
    208 			memcpy(cp, data, (size_t)datalen);
    209 			cp += datalen;
    210 		}
    211 		hp->ancount = htons(1);
    212 		break;
    213 
    214 	default:
    215 		return (-1);
    216 	}
    217 	return (cp - buf);
    218 }
    219 
    220 #ifdef RES_USE_EDNS0
    221 /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
    222 
    223 int
    224 res_nopt(res_state statp,
    225 	 int n0,		/*%< current offset in buffer */
    226 	 u_char *buf,		/*%< buffer to put query */
    227 	 int buflen,		/*%< size of buffer */
    228 	 int anslen)		/*%< UDP answer buffer size */
    229 {
    230 	register HEADER *hp;
    231 	register u_char *cp, *ep;
    232 	u_int16_t flags = 0;
    233 
    234 #ifdef DEBUG
    235 	if ((statp->options & RES_DEBUG) != 0U)
    236 		printf(";; res_nopt()\n");
    237 #endif
    238 
    239 	hp = (HEADER *)(void *)buf;
    240 	cp = buf + n0;
    241 	ep = buf + buflen;
    242 
    243 	if ((ep - cp) < 1 + RRFIXEDSZ)
    244 		return (-1);
    245 
    246 	*cp++ = 0;			/*%< "." */
    247 	ns_put16(ns_t_opt, cp);		/*%< TYPE */
    248 	cp += INT16SZ;
    249 	ns_put16(anslen & 0xffff, cp);	/*%< CLASS = UDP payload size */
    250 	cp += INT16SZ;
    251 	*cp++ = NOERROR;		/*%< extended RCODE */
    252 	*cp++ = 0;			/*%< EDNS version */
    253 
    254 	if (statp->options & RES_USE_DNSSEC) {
    255 #ifdef DEBUG
    256 		if (statp->options & RES_DEBUG)
    257 			printf(";; res_opt()... ENDS0 DNSSEC\n");
    258 #endif
    259 		flags |= NS_OPT_DNSSEC_OK;
    260 	}
    261 	ns_put16(flags, cp);
    262 	cp += INT16SZ;
    263 
    264 	ns_put16(0U, cp);		/*%< RDLEN */
    265 	cp += INT16SZ;
    266 
    267 	hp->arcount = htons(ntohs(hp->arcount) + 1);
    268 
    269 	return (cp - buf);
    270 }
    271 
    272 /*
    273  * Construct variable data (RDATA) block for OPT psuedo-RR, append it
    274  * to the buffer, then update the RDLEN field (previously set to zero by
    275  * res_nopt()) with the new RDATA length.
    276  */
    277 int
    278 res_nopt_rdata(res_state statp,
    279 	  int n0,	 	/*%< current offset in buffer */
    280 	  u_char *buf,	 	/*%< buffer to put query */
    281 	  int buflen,		/*%< size of buffer */
    282 	  u_char *rdata,	/*%< ptr to start of opt rdata */
    283 	  u_short code,		/*%< OPTION-CODE */
    284 	  u_short len,		/*%< OPTION-LENGTH */
    285 	  u_char *data)		/*%< OPTION_DATA */
    286 {
    287 	register u_char *cp, *ep;
    288 
    289 #ifdef DEBUG
    290 	if ((statp->options & RES_DEBUG) != 0U)
    291 		printf(";; res_nopt_rdata()\n");
    292 #endif
    293 
    294 	cp = buf + n0;
    295 	ep = buf + buflen;
    296 
    297 	if ((ep - cp) < (4 + len))
    298 		return (-1);
    299 
    300 	if (rdata < (buf + 2) || rdata >= ep)
    301 		return (-1);
    302 
    303 	ns_put16(code, cp);
    304 	cp += INT16SZ;
    305 
    306 	ns_put16(len, cp);
    307 	cp += INT16SZ;
    308 
    309 	memcpy(cp, data, len);
    310 	cp += len;
    311 
    312 	len = cp - rdata;
    313 	ns_put16(len, rdata - 2);	/* Update RDLEN field */
    314 
    315 	return (cp - buf);
    316 }
    317 #endif
    318 
    319 /*! \file */
    320