lib/libc/resolv/res_mkquery.c

   1 /*      $NetBSD: res_mkquery.c,v 1.13 2012/03/13 21:13:43 christos Exp $        */
   2
   3 /*
   4  * Portions Copyright (C) 2004, 2005, 2008  Internet Systems Consortium, Inc. ("ISC")
   5  * Portions Copyright (C) 1996, 1997, 1988, 1999, 2001, 2003  Internet Software Consortium.
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  12  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  13  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  14  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  15  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  16  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  17  * PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 /*
  21  * Copyright (c) 1985, 1993
  22  *    The Regents of the University of California.  All rights reserved.
  23  *
  24  * Redistribution and use in source and binary forms, with or without
  25  * modification, are permitted provided that the following conditions
  26  * are met:
  27  * 1. Redistributions of source code must retain the above copyright
  28  *    notice, this list of conditions and the following disclaimer.
  29  * 2. Redistributions in binary form must reproduce the above copyright
  30  *    notice, this list of conditions and the following disclaimer in the
  31  *    documentation and/or other materials provided with the distribution.
  32  * 3. All advertising materials mentioning features or use of this software
  33  *    must display the following acknowledgement:
  34  *      This product includes software developed by the University of
  35  *      California, Berkeley and its contributors.
  36  * 4. Neither the name of the University nor the names of its contributors
  37  *    may be used to endorse or promote products derived from this software
  38  *    without specific prior written permission.
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  */
  52
  53 /*
  54  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  55  *
  56  * Permission to use, copy, modify, and distribute this software for any
  57  * purpose with or without fee is hereby granted, provided that the above
  58  * copyright notice and this permission notice appear in all copies, and that
  59  * the name of Digital Equipment Corporation not be used in advertising or
  60  * publicity pertaining to distribution of the document or software without
  61  * specific, written prior permission.
  62  *
  63  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  64  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  65  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  66  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  67  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  68  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  69  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  70  * 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 1.10 2008/12/11 09:59:00 marka Exp";
  78 #else
  79 __RCSID("$NetBSD: res_mkquery.c,v 1.13 2012/03/13 21:13:43 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 <assert.h>
  91 #include <netdb.h>
  92 #include <resolv.h>
  93 #include <stdio.h>
  94 #include <string.h>
  95 #include "port_after.h"
  96
  97 #if 0
  98 #ifdef __weak_alias
  99 __weak_alias(res_nmkquery,_res_nmkquery)
 100 __weak_alias(res_nopt,_res_nopt)
 101 #endif
 102 #endif
 103
 104 /* Options.  Leave them on. */
 105 #ifndef DEBUG
 106 #define DEBUG
 107 #endif
 108
 109 extern const char *_res_opcodes[];
 110
 111 /*%
 112  * Form all types of queries.
 113  * Returns the size of the result or -1.
 114  */
 115 int
 116 res_nmkquery(res_state statp,
 117              int op,                    /*!< opcode of query  */
 118              const char *dname,         /*!< domain name  */
 119              int class, int type,       /*!< class and type of query  */
 120              const u_char *data,        /*!< resource record data  */
 121              int datalen,               /*!< length of data  */
 122              const u_char *newrr_in,    /*!< new rr for modify or append  */
 123              u_char *buf,               /*!< buffer to put query  */
 124              int buflen)                /*!< size of buffer  */
 125 {
 126         register HEADER *hp;
 127         register u_char *cp, *ep;
 128         register int n;
 129         u_char *dnptrs[20], **dpp, **lastdnptr;
 130
 131         UNUSED(newrr_in);
 132
 133 #ifdef DEBUG
 134         if (statp->options & RES_DEBUG)
 135                 printf(";; res_nmkquery(%s, %s, %s, %s)\n",
 136                        _res_opcodes[op], dname, p_class(class), p_type(type));
 137 #endif
 138         /*
 139          * Initialize header fields.
 140          */
 141         if ((buf == NULL) || (buflen < HFIXEDSZ))
 142                 return (-1);
 143         memset(buf, 0, HFIXEDSZ);
 144         hp = (HEADER *)(void *)buf;
 145         statp->id = res_nrandomid(statp);
 146         hp->id = htons(statp->id);
 147         hp->opcode = op;
 148         hp->rd = (statp->options & RES_RECURSE) != 0U;
 149         hp->rcode = NOERROR;
 150         cp = buf + HFIXEDSZ;
 151         ep = buf + buflen;
 152         dpp = dnptrs;
 153         *dpp++ = buf;
 154         *dpp++ = NULL;
 155         lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
 156         /*
 157          * perform opcode specific processing
 158          */
 159         switch (op) {
 160         case QUERY:     /*FALLTHROUGH*/
 161         case NS_NOTIFY_OP:
 162                 if (ep - cp < QFIXEDSZ)
 163                         return (-1);
 164                 if ((n = dn_comp(dname, cp, (int)(ep - cp - QFIXEDSZ), dnptrs,
 165                     lastdnptr)) < 0)
 166                         return (-1);
 167                 cp += n;
 168                 ns_put16(type, cp);
 169                 cp += INT16SZ;
 170                 ns_put16(class, cp);
 171                 cp += INT16SZ;
 172                 hp->qdcount = htons(1);
 173                 if (op == QUERY || data == NULL)
 174                         break;
 175                 /*
 176                  * Make an additional record for completion domain.
 177                  */
 178                 if ((ep - cp) < RRFIXEDSZ)
 179                         return (-1);
 180                 n = dn_comp((const char *)data, cp, (int)(ep - cp - RRFIXEDSZ),
 181                             dnptrs, lastdnptr);
 182                 if (n < 0)
 183                         return (-1);
 184                 cp += n;
 185                 ns_put16(T_NULL, cp);
 186                 cp += INT16SZ;
 187                 ns_put16(class, cp);
 188                 cp += INT16SZ;
 189                 ns_put32(0, cp);
 190                 cp += INT32SZ;
 191                 ns_put16(0, cp);
 192                 cp += INT16SZ;
 193                 hp->arcount = htons(1);
 194                 break;
 195
 196         case IQUERY:
 197                 /*
 198                  * Initialize answer section
 199                  */
 200                 if (ep - cp < 1 + RRFIXEDSZ + datalen)
 201                         return (-1);
 202                 *cp++ = '\0';   /*%< no domain name */
 203                 ns_put16(type, cp);
 204                 cp += INT16SZ;
 205                 ns_put16(class, cp);
 206                 cp += INT16SZ;
 207                 ns_put32(0, cp);
 208                 cp += INT32SZ;
 209                 ns_put16(datalen, cp);
 210                 cp += INT16SZ;
 211                 if (datalen) {
 212                         memcpy(cp, data, (size_t)datalen);
 213                         cp += datalen;
 214                 }
 215                 hp->ancount = htons(1);
 216                 break;
 217
 218         default:
 219                 return (-1);
 220         }
 221         _DIAGASSERT(__type_fit(int, cp - buf));
 222         return (int)(cp - buf);
 223 }
 224
 225 #ifdef RES_USE_EDNS0
 226 /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
 227
 228 int
 229 res_nopt(res_state statp,
 230          int n0,                /*%< current offset in buffer */
 231          u_char *buf,           /*%< buffer to put query */
 232          int buflen,            /*%< size of buffer */
 233          int anslen)            /*%< UDP answer buffer size */
 234 {
 235         register HEADER *hp;
 236         register u_char *cp, *ep;
 237         u_int16_t flags = 0;
 238
 239 #ifdef DEBUG
 240         if ((statp->options & RES_DEBUG) != 0U)
 241                 printf(";; res_nopt()\n");
 242 #endif
 243
 244         hp = (HEADER *)(void *)buf;
 245         cp = buf + n0;
 246         ep = buf + buflen;
 247
 248         if ((ep - cp) < 1 + RRFIXEDSZ)
 249                 return (-1);
 250
 251         *cp++ = 0;                              /*%< "." */
 252         ns_put16(ns_t_opt, cp);                 /*%< TYPE */
 253         cp += INT16SZ;
 254         ns_put16(anslen & 0xffff, cp);          /*%< CLASS = UDP payload size */
 255         cp += INT16SZ;
 256         *cp++ = NOERROR;                        /*%< extended RCODE */
 257         *cp++ = 0;                              /*%< EDNS version */
 258
 259         if (statp->options & RES_USE_DNSSEC) {
 260 #ifdef DEBUG
 261                 if (statp->options & RES_DEBUG)
 262                         printf(";; res_opt()... ENDS0 DNSSEC\n");
 263 #endif
 264                 flags |= NS_OPT_DNSSEC_OK;
 265         }
 266         ns_put16(flags, cp);
 267         cp += INT16SZ;
 268
 269         ns_put16(0U, cp);                       /*%< RDLEN */
 270         cp += INT16SZ;
 271
 272         hp->arcount = htons(ntohs(hp->arcount) + 1);
 273
 274         _DIAGASSERT(__type_fit(int, cp - buf));
 275         return (int)(cp - buf);
 276 }
 277
 278 /*
 279  * Construct variable data (RDATA) block for OPT psuedo-RR, append it
 280  * to the buffer, then update the RDLEN field (previously set to zero by
 281  * res_nopt()) with the new RDATA length.
 282  */
 283 int
 284 res_nopt_rdata(res_state statp,
 285           int n0,               /*%< current offset in buffer */
 286           u_char *buf,          /*%< buffer to put query */
 287           int buflen,           /*%< size of buffer */
 288           u_char *rdata,        /*%< ptr to start of opt rdata */
 289           u_short code,         /*%< OPTION-CODE */
 290           u_short len,          /*%< OPTION-LENGTH */
 291           u_char *data)         /*%< OPTION_DATA */
 292 {
 293         register u_char *cp, *ep;
 294
 295 #ifdef DEBUG
 296         if ((statp->options & RES_DEBUG) != 0U)
 297                 printf(";; res_nopt_rdata()\n");
 298 #endif
 299
 300         cp = buf + n0;
 301         ep = buf + buflen;
 302
 303         if ((ep - cp) < (4 + len))
 304                 return (-1);
 305
 306         if (rdata < (buf + 2) || rdata >= ep)
 307                 return (-1);
 308
 309         ns_put16(code, cp);
 310         cp += INT16SZ;
 311
 312         ns_put16(len, cp);
 313         cp += INT16SZ;
 314
 315         memcpy(cp, data, (size_t)len);
 316         cp += len;
 317
 318         _DIAGASSERT(__type_fit(u_short, cp - rdata));
 319         len = (u_short)(cp - rdata);
 320         ns_put16(len, rdata - 2);       /* Update RDLEN field */
 321
 322         _DIAGASSERT(__type_fit(int, cp - buf));
 323         return (int)(cp - buf);
 324 }
 325 #endif
 326
 327 /*! \file */