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 #include <sys/time.h>
  81
  82 /* Options.  Leave them on. */
  83 /* #define DEBUG */
  84
  85 #ifdef _LIBC
  86 # include <hp-timing.h>
  87 # include <stdint.h>
  88 # if HP_TIMING_AVAIL
  89 #  define RANDOM_BITS(Var) { uint64_t v64; HP_TIMING_NOW (v64); Var = v64; }
  90 # endif
  91 #endif
  92
  93 /*
  94  * Form all types of queries.
  95  * Returns the size of the result or -1.
  96  */
  97 int
  98 res_nmkquery(res_state statp,
  99              int op,                    /* opcode of query */
 100              const char *dname,         /* domain name */
 101              int class, int type,       /* class and type of query */
 102              const u_char *data,        /* resource record data */
 103              int datalen,               /* length of data */
 104              const u_char *newrr_in,    /* new rr for modify or append */
 105              u_char *buf,               /* buffer to put query */
 106              int buflen)                /* size of buffer */
 107 {
 108         HEADER *hp;
 109         u_char *cp;
 110         int n;
 111         u_char *dnptrs[20], **dpp, **lastdnptr;
 112
 113 #ifdef DEBUG
 114         if (statp->options & RES_DEBUG)
 115                 printf(";; res_nmkquery(%s, %s, %s, %s)\n",
 116                        _res_opcodes[op], dname, p_class(class), p_type(type));
 117 #endif
 118         /*
 119          * Initialize header fields.
 120          */
 121         if ((buf == NULL) || (buflen < HFIXEDSZ))
 122                 return (-1);
 123         memset(buf, 0, HFIXEDSZ);
 124         hp = (HEADER *) buf;
 125         /* We randomize the IDs every time.  The old code just
 126            incremented by one after the initial randomization which
 127            still predictable if the application does multiple
 128            requests.  */
 129         int randombits;
 130         do
 131           {
 132 #ifdef RANDOM_BITS
 133             RANDOM_BITS (randombits);
 134 #else
 135             struct timeval tv;
 136             __gettimeofday (&tv, NULL);
 137             randombits = (tv.tv_sec << 8) ^ tv.tv_usec;
 138 #endif
 139           }
 140         while ((randombits & 0xffff) == 0);
 141         statp->id = (statp->id + randombits) & 0xffff;
 142         hp->id = statp->id;
 143         hp->opcode = op;
 144         hp->rd = (statp->options & RES_RECURSE) != 0;
 145         hp->rcode = NOERROR;
 146         cp = buf + HFIXEDSZ;
 147         buflen -= HFIXEDSZ;
 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 NS_NOTIFY_OP:
 157                 if ((buflen -= QFIXEDSZ + (data == NULL ? 0 : RRFIXEDSZ)) < 0)
 158                         return (-1);
 159                 goto compose;
 160
 161         case QUERY:
 162                 if ((buflen -= QFIXEDSZ) < 0)
 163                         return (-1);
 164         compose:
 165                 n = ns_name_compress(dname, cp, buflen,
 166                                      (const u_char **) dnptrs,
 167                                      (const u_char **) lastdnptr);
 168                 if (n < 0)
 169                         return (-1);
 170                 cp += n;
 171                 buflen -= n;
 172                 NS_PUT16 (type, cp);
 173                 NS_PUT16 (class, cp);
 174                 hp->qdcount = htons(1);
 175                 if (op == QUERY || data == NULL)
 176                         break;
 177                 /*
 178                  * Make an additional record for completion domain.
 179                  */
 180                 n = ns_name_compress((char *)data, cp, buflen,
 181                                      (const u_char **) dnptrs,
 182                                      (const u_char **) lastdnptr);
 183                 if (__glibc_unlikely (n < 0))
 184                         return (-1);
 185                 cp += n;
 186                 buflen -= n;
 187                 NS_PUT16 (T_NULL, cp);
 188                 NS_PUT16 (class, cp);
 189                 NS_PUT32 (0, cp);
 190                 NS_PUT16 (0, cp);
 191                 hp->arcount = htons(1);
 192                 break;
 193
 194         case IQUERY:
 195                 /*
 196                  * Initialize answer section
 197                  */
 198                 if (__glibc_unlikely (buflen < 1 + RRFIXEDSZ + datalen))
 199                         return (-1);
 200                 *cp++ = '\0';   /* no domain name */
 201                 NS_PUT16 (type, cp);
 202                 NS_PUT16 (class, cp);
 203                 NS_PUT32 (0, cp);
 204                 NS_PUT16 (datalen, cp);
 205                 if (datalen) {
 206                         memcpy(cp, data, datalen);
 207                         cp += datalen;
 208                 }
 209                 hp->ancount = htons(1);
 210                 break;
 211
 212         default:
 213                 return (-1);
 214         }
 215         return (cp - buf);
 216 }
 217 libresolv_hidden_def (res_nmkquery)
 218
 219
 220 /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
 221 #ifndef T_OPT
 222 #define T_OPT   41
 223 #endif
 224
 225 int
 226 __res_nopt(res_state statp,
 227            int n0,                /* current offset in buffer */
 228            u_char *buf,           /* buffer to put query */
 229            int buflen,            /* size of buffer */
 230            int anslen)            /* UDP answer buffer size */
 231 {
 232         u_int16_t flags = 0;
 233
 234 #ifdef DEBUG
 235         if ((statp->options & RES_DEBUG) != 0U)
 236                 printf(";; res_nopt()\n");
 237 #endif
 238
 239         HEADER *hp = (HEADER *) buf;
 240         u_char *cp = buf + n0;
 241         u_char *ep = buf + buflen;
 242
 243         if ((ep - cp) < 1 + RRFIXEDSZ)
 244                 return -1;
 245
 246         *cp++ = 0;      /* "." */
 247
 248         NS_PUT16(T_OPT, cp);    /* TYPE */
 249         NS_PUT16(MIN(anslen, 0xffff), cp);      /* CLASS = UDP payload size */
 250         *cp++ = NOERROR;        /* extended RCODE */
 251         *cp++ = 0;              /* EDNS version */
 252
 253         if (statp->options & RES_USE_DNSSEC) {
 254 #ifdef DEBUG
 255                 if (statp->options & RES_DEBUG)
 256                         printf(";; res_opt()... ENDS0 DNSSEC\n");
 257 #endif
 258                 flags |= NS_OPT_DNSSEC_OK;
 259         }
 260
 261         NS_PUT16(flags, cp);
 262         NS_PUT16(0, cp);        /* RDLEN */
 263         hp->arcount = htons(ntohs(hp->arcount) + 1);
 264
 265         return cp - buf;
 266 }
 267 libresolv_hidden_def (__res_nopt)