lib/libc/net/res_mkquery.c

   1 /*
   2  * Copyright (c) 1985, 1993
   3  *    The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)res_mkquery.c    8.1 (Berkeley) 6/4/93
  30  * $From: Id: res_mkquery.c,v 8.9 1997/04/24 22:22:36 vixie Exp $
  31  * $FreeBSD: src/lib/libc/net/res_mkquery.c,v 1.15.2.2 2002/09/20 10:45:35 nectar Exp $
  32  * $DragonFly: src/lib/libc/net/res_mkquery.c,v 1.5 2005/11/13 02:04:47 swildner Exp $
  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  * Portions Copyright (c) 1996 by Internet Software Consortium.
  57  *
  58  * Permission to use, copy, modify, and distribute this software for any
  59  * purpose with or without fee is hereby granted, provided that the above
  60  * copyright notice and this permission notice appear in all copies.
  61  *
  62  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  63  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  64  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  65  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  66  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  67  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  68  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  69  * SOFTWARE.
  70  */
  71
  72 #include <sys/types.h>
  73 #include <sys/param.h>
  74 #include <netinet/in.h>
  75 #include <arpa/nameser.h>
  76 #include <netdb.h>
  77 #include <resolv.h>
  78 #include <stdio.h>
  79 #include <string.h>
  80
  81 #include "res_config.h"
  82
  83 /*
  84  * Form all types of queries.
  85  * Returns the size of the result or -1.
  86  */
  87 int
  88 res_mkquery(int op,                     /* opcode of query */
  89             const char *dname,          /* domain name */
  90             int class,                  /* class of query */
  91             int type,                   /* type of query */
  92             const u_char *data,         /* resource record data */
  93             int datalen,                /* length of data */
  94             const u_char *newrr_in,     /* new rr for modify or append */
  95             u_char *buf,                /* buffer to put query */
  96             int buflen)                 /* size of buffer */
  97 {
  98         HEADER *hp;
  99         u_char *cp;
 100         int n;
 101         u_char *dnptrs[20], **dpp, **lastdnptr;
 102
 103         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 104                 h_errno = NETDB_INTERNAL;
 105                 return (-1);
 106         }
 107 #ifdef DEBUG
 108         if (_res.options & RES_DEBUG)
 109                 printf(";; res_mkquery(%d, %s, %d, %d)\n",
 110                        op, dname, class, type);
 111 #endif
 112         /*
 113          * Initialize header fields.
 114          */
 115         if ((buf == NULL) || (buflen < HFIXEDSZ))
 116                 return (-1);
 117         memset(buf, 0, HFIXEDSZ);
 118         hp = (HEADER *) buf;
 119         hp->id = htons(++_res.id);
 120         hp->opcode = op;
 121         hp->rd = (_res.options & RES_RECURSE) != 0;
 122         hp->rcode = NOERROR;
 123         cp = buf + HFIXEDSZ;
 124         buflen -= HFIXEDSZ;
 125         dpp = dnptrs;
 126         *dpp++ = buf;
 127         *dpp++ = NULL;
 128         lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
 129         /*
 130          * perform opcode specific processing
 131          */
 132         switch (op) {
 133         case QUERY:     /*FALLTHROUGH*/
 134         case NS_NOTIFY_OP:
 135                 if ((buflen -= QFIXEDSZ) < 0)
 136                         return (-1);
 137                 if ((n = dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0)
 138                         return (-1);
 139                 cp += n;
 140                 buflen -= n;
 141                 __putshort(type, cp);
 142                 cp += INT16SZ;
 143                 __putshort(class, cp);
 144                 cp += INT16SZ;
 145                 hp->qdcount = htons(1);
 146                 if (op == QUERY || data == NULL)
 147                         break;
 148                 /*
 149                  * Make an additional record for completion domain.
 150                  */
 151                 buflen -= RRFIXEDSZ;
 152                 n = dn_comp((char *)data, cp, buflen, dnptrs, lastdnptr);
 153                 if (n < 0)
 154                         return (-1);
 155                 cp += n;
 156                 buflen -= n;
 157                 __putshort(T_NULL, cp);
 158                 cp += INT16SZ;
 159                 __putshort(class, cp);
 160                 cp += INT16SZ;
 161                 __putlong(0, cp);
 162                 cp += INT32SZ;
 163                 __putshort(0, cp);
 164                 cp += INT16SZ;
 165                 hp->arcount = htons(1);
 166                 break;
 167
 168         case IQUERY:
 169                 /*
 170                  * Initialize answer section
 171                  */
 172                 if (buflen < 1 + RRFIXEDSZ + datalen)
 173                         return (-1);
 174                 *cp++ = '\0';   /* no domain name */
 175                 __putshort(type, cp);
 176                 cp += INT16SZ;
 177                 __putshort(class, cp);
 178                 cp += INT16SZ;
 179                 __putlong(0, cp);
 180                 cp += INT32SZ;
 181                 __putshort(datalen, cp);
 182                 cp += INT16SZ;
 183                 if (datalen) {
 184                         memcpy(cp, data, datalen);
 185                         cp += datalen;
 186                 }
 187                 hp->ancount = htons(1);
 188                 break;
 189
 190         default:
 191                 return (-1);
 192         }
 193         return (cp - buf);
 194 }
 195
 196 /*
 197  * Weak aliases for applications that use certain private entry points,
 198  * and fail to include <resolv.h>.
 199  */
 200 #undef res_mkquery
 201 __weak_reference(__res_mkquery, res_mkquery);
 202
 203 /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
 204 int
 205 res_opt(int n0,
 206         u_char *buf,            /* buffer to put query */
 207         int buflen,             /* size of buffer */
 208         int anslen)             /* answer buffer length */
 209 {
 210         HEADER *hp;
 211         u_char *cp;
 212
 213         hp = (HEADER *) buf;
 214         cp = buf + n0;
 215         buflen -= n0;
 216
 217         if (buflen < 1 + RRFIXEDSZ)
 218                 return -1;
 219
 220         *cp++ = 0;      /* "." */
 221         buflen--;
 222
 223         __putshort(T_OPT, cp);  /* TYPE */
 224         cp += INT16SZ;
 225         if (anslen > 0xffff)
 226                 anslen = 0xffff;                /* limit to 16bit value */
 227         __putshort(anslen & 0xffff, cp);        /* CLASS = UDP payload size */
 228         cp += INT16SZ;
 229         *cp++ = NOERROR;        /* extended RCODE */
 230         *cp++ = 0;              /* EDNS version */
 231         __putshort(0, cp);      /* MBZ */
 232         cp += INT16SZ;
 233         __putshort(0, cp);      /* RDLEN */
 234         cp += INT16SZ;
 235         hp->arcount = htons(ntohs(hp->arcount) + 1);
 236         buflen -= RRFIXEDSZ;
 237
 238         return cp - buf;
 239 }