resolv/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  * 4. 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
  30 /*
  31  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  32  *
  33  * Permission to use, copy, modify, and distribute this software for any
  34  * purpose with or without fee is hereby granted, provided that the above
  35  * copyright notice and this permission notice appear in all copies, and that
  36  * the name of Digital Equipment Corporation not be used in advertising or
  37  * publicity pertaining to distribution of the document or software without
  38  * specific, written prior permission.
  39  *
  40  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  41  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  42  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  43  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  44  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  45  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  46  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  47  * SOFTWARE.
  48  */
  49
  50 /*
  51  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  52  *
  53  * Permission to use, copy, modify, and distribute this software for any
  54  * purpose with or without fee is hereby granted, provided that the above
  55  * copyright notice and this permission notice appear in all copies.
  56  *
  57  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  58  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  59  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  60  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  61  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  62  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  63  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  64  * SOFTWARE.
  65  */
  66
  67 #if defined(LIBC_SCCS) && !defined(lint)
  68 static const char sccsid[] = "@(#)res_mkquery.c 8.1 (Berkeley) 6/4/93";
  69 static const char rcsid[] = "$BINDId: res_mkquery.c,v 8.12 1999/10/13 16:39:40 vixie Exp $";
  70 #endif /* LIBC_SCCS and not lint */
  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 /* Options.  Leave them on. */
  82 /* #define DEBUG */
  83
  84 #ifdef _LIBC
  85 # include <hp-timing.h>
  86 # if HP_TIMING_AVAIL
  87 #  define RANDOM_BITS(Var) { uint64_t v64; HP_TIMING_NOW (v64); Var = v64; }
  88 # endif
  89 #endif
  90
  91 /*
  92  * Form all types of queries.
  93  * Returns the size of the result or -1.
  94  */
  95 int
  96 res_nmkquery(res_state statp,
  97              int op,                    /* opcode of query */
  98              const char *dname,         /* domain name */
  99              int class, int type,       /* class and type of query */
 100              const u_char *data,        /* resource record data */
 101              int datalen,               /* length of data */
 102              const u_char *newrr_in,    /* new rr for modify or append */
 103              u_char *buf,               /* buffer to put query */
 104              int buflen)                /* size of buffer */
 105 {
 106         register HEADER *hp;
 107         register u_char *cp;
 108         register int n;
 109         u_char *dnptrs[20], **dpp, **lastdnptr;
 110
 111 #ifdef DEBUG
 112         if (statp->options & RES_DEBUG)
 113                 printf(";; res_nmkquery(%s, %s, %s, %s)\n",
 114                        _res_opcodes[op], dname, p_class(class), p_type(type));
 115 #endif
 116         /*
 117          * Initialize header fields.
 118          */
 119         if ((buf == NULL) || (buflen < HFIXEDSZ))
 120                 return (-1);
 121         memset(buf, 0, HFIXEDSZ);
 122         hp = (HEADER *) buf;
 123         /* We randomize the IDs every time.  The old code just
 124            incremented by one after the initial randomization which
 125            still predictable if the application does multiple
 126            requests.  */
 127         int randombits;
 128         do
 129           {
 130 #ifdef RANDOM_BITS
 131             RANDOM_BITS (randombits);
 132 #else
 133             struct timeval tv;
 134             __gettimeofday (&tv, NULL);
 135             randombits = (tv.tv_sec << 8) ^ tv.tv_usec;
 136 #endif
 137           }
 138         while ((randombits & 0xffff) == 0);
 139         statp->id = (statp->id + randombits) & 0xffff;
 140         hp->id = statp->id;
 141         hp->opcode = op;
 142         hp->rd = (statp->options & RES_RECURSE) != 0;
 143         hp->rcode = NOERROR;
 144         cp = buf + HFIXEDSZ;
 145         buflen -= HFIXEDSZ;
 146         dpp = dnptrs;
 147         *dpp++ = buf;
 148         *dpp++ = NULL;
 149         lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
 150         /*
 151          * perform opcode specific processing
 152          */
 153         switch (op) {
 154         case NS_NOTIFY_OP:
 155                 if ((buflen -= QFIXEDSZ + (data == NULL ? 0 : RRFIXEDSZ)) < 0)
 156                         return (-1);
 157                 goto compose;
 158
 159         case QUERY:
 160                 if ((buflen -= QFIXEDSZ) < 0)
 161                         return (-1);
 162         compose:
 163                 if ((n = dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0)
 164                         return (-1);
 165                 cp += n;
 166                 buflen -= n;
 167                 NS_PUT16 (type, cp);
 168                 NS_PUT16 (class, cp);
 169                 hp->qdcount = htons(1);
 170                 if (op == QUERY || data == NULL)
 171                         break;
 172                 /*
 173                  * Make an additional record for completion domain.
 174                  */
 175                 n = dn_comp((char *)data, cp, buflen, dnptrs, lastdnptr);
 176                 if (__builtin_expect (n < 0, 0))
 177                         return (-1);
 178                 cp += n;
 179                 buflen -= n;
 180                 NS_PUT16 (T_NULL, cp);
 181                 NS_PUT16 (class, cp);
 182                 NS_PUT32 (0, cp);
 183                 NS_PUT16 (0, cp);
 184                 hp->arcount = htons(1);
 185                 break;
 186
 187         case IQUERY:
 188                 /*
 189                  * Initialize answer section
 190                  */
 191                 if (__builtin_expect (buflen < 1 + RRFIXEDSZ + datalen, 0))
 192                         return (-1);
 193                 *cp++ = '\0';   /* no domain name */
 194                 NS_PUT16 (type, cp);
 195                 NS_PUT16 (class, cp);
 196                 NS_PUT32 (0, cp);
 197                 NS_PUT16 (datalen, cp);
 198                 if (datalen) {
 199                         memcpy(cp, data, datalen);
 200                         cp += datalen;
 201                 }
 202                 hp->ancount = htons(1);
 203                 break;
 204
 205         default:
 206                 return (-1);
 207         }
 208         return (cp - buf);
 209 }
 210 libresolv_hidden_def (res_nmkquery)
 211
 212
 213 /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
 214 #ifndef T_OPT
 215 #define T_OPT   41
 216 #endif
 217
 218 int
 219 __res_nopt(res_state statp,
 220            int n0,                /* current offset in buffer */
 221            u_char *buf,           /* buffer to put query */
 222            int buflen,            /* size of buffer */
 223            int anslen)            /* UDP answer buffer size */
 224 {
 225         u_int16_t flags = 0;
 226
 227 #ifdef DEBUG
 228         if ((statp->options & RES_DEBUG) != 0U)
 229                 printf(";; res_nopt()\n");
 230 #endif
 231
 232         HEADER *hp = (HEADER *) buf;
 233         u_char *cp = buf + n0;
 234         u_char *ep = buf + buflen;
 235
 236         if ((ep - cp) < 1 + RRFIXEDSZ)
 237                 return -1;
 238
 239         *cp++ = 0;      /* "." */
 240
 241         ns_put16(T_OPT, cp);    /* TYPE */
 242         cp += INT16SZ;
 243         ns_put16(anslen & 0xffff, cp);  /* CLASS = UDP payload size */
 244         cp += INT16SZ;
 245         *cp++ = NOERROR;        /* extended RCODE */
 246         *cp++ = 0;              /* EDNS version */
 247         /* XXX Once we support DNSSEC we change the flag value here.  */
 248         ns_put16(flags, cp);
 249         cp += INT16SZ;
 250         ns_put16(0, cp);        /* RDLEN */
 251         cp += INT16SZ;
 252         hp->arcount = htons(ntohs(hp->arcount) + 1);
 253
 254         return cp - buf;
 255 }
 256 libresolv_hidden_def (__res_nopt)