lib/libc/resolv/res_mkquery.c

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