lib/libc/resolv/res_mkquery.c

   1 /*      $NetBSD: res_mkquery.c,v 1.15 2015/02/24 17:56:20 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. Neither the name of the University nor the names of its contributors
  33  *    may be used to endorse or promote products derived from this software
  34  *    without specific prior written permission.
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  37  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  39  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  40  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  41  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  42  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  44  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  45  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  46  * SUCH DAMAGE.
  47  */
  48
  49 /*
  50  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  51  *
  52  * Permission to use, copy, modify, and distribute this software for any
  53  * purpose with or without fee is hereby granted, provided that the above
  54  * copyright notice and this permission notice appear in all copies, and that
  55  * the name of Digital Equipment Corporation not be used in advertising or
  56  * publicity pertaining to distribution of the document or software without
  57  * specific, written prior permission.
  58  *
  59  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  60  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  61  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  62  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  63  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  64  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  65  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  66  * SOFTWARE.
  67  */
  68
  69 #include <sys/cdefs.h>
  70 #if defined(LIBC_SCCS) && !defined(lint)
  71 #ifdef notdef
  72 static const char sccsid[] = "@(#)res_mkquery.c 8.1 (Berkeley) 6/4/93";
  73 static const char rcsid[] = "Id: res_mkquery.c,v 1.10 2008/12/11 09:59:00 marka Exp";
  74 #else
  75 __RCSID("$NetBSD: res_mkquery.c,v 1.15 2015/02/24 17:56:20 christos Exp $");
  76 #endif
  77 #endif /* LIBC_SCCS and not lint */
  78
  79 #include "port_before.h"
  80
  81 #include "namespace.h"
  82 #include <sys/types.h>
  83 #include <sys/param.h>
  84 #include <netinet/in.h>
  85 #include <arpa/nameser.h>
  86 #include <assert.h>
  87 #include <netdb.h>
  88 #include <resolv.h>
  89 #include <stdio.h>
  90 #include <string.h>
  91 #include "port_after.h"
  92
  93 #if 0
  94 #ifdef __weak_alias
  95 __weak_alias(res_nmkquery,_res_nmkquery)
  96 __weak_alias(res_nopt,_res_nopt)
  97 #endif
  98 #endif
  99
 100 /* Options.  Leave them on. */
 101 #ifndef DEBUG
 102 #define DEBUG
 103 #endif
 104
 105 extern const char *_res_opcodes[];
 106
 107 /*%
 108  * Form all types of queries.
 109  * Returns the size of the result or -1.
 110  */
 111 int
 112 res_nmkquery(res_state statp,
 113              int op,                    /*!< opcode of query  */
 114              const char *dname,         /*!< domain name  */
 115              int class, int type,       /*!< class and type of query  */
 116              const u_char *data,        /*!< resource record data  */
 117              int datalen,               /*!< length of data  */
 118              const u_char *newrr_in,    /*!< new rr for modify or append  */
 119              u_char *buf,               /*!< buffer to put query  */
 120              int buflen)                /*!< size of buffer  */
 121 {
 122         register HEADER *hp;
 123         register u_char *cp, *ep;
 124         register int n;
 125         u_char *dnptrs[20], **dpp, **lastdnptr;
 126
 127         UNUSED(newrr_in);
 128
 129 #ifdef DEBUG
 130         if (statp->options & RES_DEBUG)
 131                 printf(";; res_nmkquery(%s, %s, %s, %s)\n",
 132                        _res_opcodes[op], dname, p_class(class), p_type(type));
 133 #endif
 134         /*
 135          * Initialize header fields.
 136          */
 137         if ((buf == NULL) || (buflen < HFIXEDSZ))
 138                 return (-1);
 139         memset(buf, 0, HFIXEDSZ);
 140         hp = (HEADER *)(void *)buf;
 141         statp->id = res_nrandomid(statp);
 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, (int)(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, (int)(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         _DIAGASSERT(__type_fit(int, cp - buf));
 218         return (int)(cp - buf);
 219 }
 220
 221 #ifdef RES_USE_EDNS0
 222 /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
 223
 224 int
 225 res_nopt(res_state statp,
 226          int n0,                /*%< current offset in buffer */
 227          u_char *buf,           /*%< buffer to put query */
 228          int buflen,            /*%< size of buffer */
 229          int anslen)            /*%< UDP answer buffer size */
 230 {
 231         register HEADER *hp;
 232         register u_char *cp, *ep;
 233         u_int16_t flags = 0;
 234
 235 #ifdef DEBUG
 236         if ((statp->options & RES_DEBUG) != 0U)
 237                 printf(";; res_nopt()\n");
 238 #endif
 239
 240         hp = (HEADER *)(void *)buf;
 241         cp = buf + n0;
 242         ep = buf + buflen;
 243
 244         if ((ep - cp) < 1 + RRFIXEDSZ)
 245                 return (-1);
 246
 247         *cp++ = 0;                              /*%< "." */
 248         ns_put16(ns_t_opt, cp);                 /*%< TYPE */
 249         cp += INT16SZ;
 250         if (anslen > 0xffff)
 251                 anslen = 0xffff;
 252         ns_put16(anslen, cp);                   /*%< CLASS = UDP payload size */
 253         cp += INT16SZ;
 254         *cp++ = NOERROR;                        /*%< extended RCODE */
 255         *cp++ = 0;                              /*%< EDNS version */
 256
 257         if (statp->options & RES_USE_DNSSEC) {
 258 #ifdef DEBUG
 259                 if (statp->options & RES_DEBUG)
 260                         printf(";; res_opt()... ENDS0 DNSSEC\n");
 261 #endif
 262                 flags |= NS_OPT_DNSSEC_OK;
 263         }
 264         ns_put16(flags, cp);
 265         cp += INT16SZ;
 266
 267         ns_put16(0U, cp);                       /*%< RDLEN */
 268         cp += INT16SZ;
 269
 270         hp->arcount = htons(ntohs(hp->arcount) + 1);
 271
 272         _DIAGASSERT(__type_fit(int, cp - buf));
 273         return (int)(cp - buf);
 274 }
 275
 276 /*
 277  * Construct variable data (RDATA) block for OPT psuedo-RR, append it
 278  * to the buffer, then update the RDLEN field (previously set to zero by
 279  * res_nopt()) with the new RDATA length.
 280  */
 281 int
 282 res_nopt_rdata(res_state statp,
 283           int n0,               /*%< current offset in buffer */
 284           u_char *buf,          /*%< buffer to put query */
 285           int buflen,           /*%< size of buffer */
 286           u_char *rdata,        /*%< ptr to start of opt rdata */
 287           u_short code,         /*%< OPTION-CODE */
 288           u_short len,          /*%< OPTION-LENGTH */
 289           u_char *data)         /*%< OPTION_DATA */
 290 {
 291         register u_char *cp, *ep;
 292
 293 #ifdef DEBUG
 294         if ((statp->options & RES_DEBUG) != 0U)
 295                 printf(";; res_nopt_rdata()\n");
 296 #endif
 297
 298         cp = buf + n0;
 299         ep = buf + buflen;
 300
 301         if ((ep - cp) < (4 + len))
 302                 return (-1);
 303
 304         if (rdata < (buf + 2) || rdata >= ep)
 305                 return (-1);
 306
 307         ns_put16(code, cp);
 308         cp += INT16SZ;
 309
 310         ns_put16(len, cp);
 311         cp += INT16SZ;
 312
 313         memcpy(cp, data, (size_t)len);
 314         cp += len;
 315
 316         _DIAGASSERT(__type_fit(u_short, cp - rdata));
 317         len = (u_short)(cp - rdata);
 318         ns_put16(len, rdata - 2);       /* Update RDLEN field */
 319
 320         _DIAGASSERT(__type_fit(int, cp - buf));
 321         return (int)(cp - buf);
 322 }
 323 #endif
 324
 325 /*! \file */