StdLib/BsdSocketLib/ns_parse.c

   1 /*
   2  * Copyright (c) 1996 by Internet Software Consortium.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
   9  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  10  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  11  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  12  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  13  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  14  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  15  * SOFTWARE.
  16  */
  17
  18 /*
  19  * Portions copyright (c) 1999, 2000
  20  * Intel Corporation.
  21  * All rights reserved.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  *
  27  * 1. Redistributions of source code must retain the above copyright
  28  *    notice, this list of conditions and the following disclaimer.
  29  *
  30  * 2. Redistributions in binary form must reproduce the above copyright
  31  *    notice, this list of conditions and the following disclaimer in the
  32  *    documentation and/or other materials provided with the distribution.
  33  *
  34  * 3. All advertising materials mentioning features or use of this software
  35  *    must display the following acknowledgement:
  36  *
  37  *    This product includes software developed by Intel Corporation and
  38  *    its contributors.
  39  *
  40  * 4. Neither the name of Intel Corporation or its contributors may be
  41  *    used to endorse or promote products derived from this software
  42  *    without specific prior written permission.
  43  *
  44  * THIS SOFTWARE IS PROVIDED BY INTEL CORPORATION AND CONTRIBUTORS ``AS IS''
  45  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  47  * ARE DISCLAIMED.  IN NO EVENT SHALL INTEL CORPORATION OR CONTRIBUTORS BE
  48  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  49  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  50  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  51  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  52  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  53  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  54  * THE POSSIBILITY OF SUCH DAMAGE.
  55  *
  56  */
  57
  58 #ifndef lint
  59 static char rcsid[] = "$Id: ns_parse.c,v 1.1.1.1 2003/11/19 01:51:33 kyu3 Exp $";
  60 #endif
  61
  62 #include <sys/types.h>
  63
  64 #include <netinet/in.h>
  65 #include <arpa/nameser.h>
  66
  67 #include <errno.h>
  68 #include <resolv.h>
  69 #include <string.h>
  70
  71 /* These need to be in the same order as the nres.h:ns_flag enum. */
  72 struct _ns_flagdata _ns_flagdata[16] = {
  73         { 0x8000, 15 },         /* qr. */
  74         { 0x7800, 11 },         /* opcode. */
  75         { 0x0400, 10 },         /* aa. */
  76         { 0x0200, 9 },          /* tc. */
  77         { 0x0100, 8 },          /* rd. */
  78         { 0x0080, 7 },          /* ra. */
  79         { 0x0040, 6 },          /* z. */
  80         { 0x0020, 5 },          /* ad. */
  81         { 0x0010, 4 },          /* cd. */
  82         { 0x000f, 0 },          /* rcode. */
  83         { 0x0000, 0 },          /* expansion (1/6). */
  84         { 0x0000, 0 },          /* expansion (2/6). */
  85         { 0x0000, 0 },          /* expansion (3/6). */
  86         { 0x0000, 0 },          /* expansion (4/6). */
  87         { 0x0000, 0 },          /* expansion (5/6). */
  88         { 0x0000, 0 },          /* expansion (6/6). */
  89 };
  90
  91 static int
  92 skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) {
  93         const u_char *optr = ptr;
  94
  95         for ((void)NULL; count > 0; count--) {
  96                 int b, rdlength;
  97
  98                 b = dn_skipname(ptr, eom);
  99                 if (b < 0)
 100                         goto emsgsize;
 101                 ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
 102                 if (section != ns_s_qd) {
 103                         if (ptr + NS_INT32SZ > eom)
 104                                 goto emsgsize;
 105                         ptr += NS_INT32SZ/*TTL*/;
 106                         if (ptr + NS_INT16SZ > eom)
 107                                 goto emsgsize;
 108                         NS_GET16(rdlength, ptr);
 109                         ptr += rdlength/*RData*/;
 110                 }
 111         }
 112         if (ptr > eom)
 113                 goto emsgsize;
 114         return ((int)(ptr - optr));
 115  emsgsize:
 116         errno = EMSGSIZE;
 117         return (-1);
 118 }
 119
 120 int
 121 ns_initparse(const u_char *msg, int msglen, ns_msg *handle) {
 122         const u_char *eom = msg + msglen;
 123         int i;
 124
 125         memset(handle, 0x5e, sizeof *handle);
 126         handle->_msg = msg;
 127         handle->_eom = eom;
 128         if (msg + NS_INT16SZ > eom)
 129                 goto emsgsize;
 130         NS_GET16(handle->_id, msg);
 131         if (msg + NS_INT16SZ > eom)
 132                 goto emsgsize;
 133         NS_GET16(handle->_flags, msg);
 134         for (i = 0; i < ns_s_max; i++) {
 135                 if (msg + NS_INT16SZ > eom)
 136                         goto emsgsize;
 137                 NS_GET16(handle->_counts[i], msg);
 138         }
 139         for (i = 0; i < ns_s_max; i++)
 140                 if (handle->_counts[i] == 0)
 141                         handle->_sections[i] = NULL;
 142                 else {
 143                         int b = skiprr(msg, eom, (ns_sect)i,
 144                                        handle->_counts[i]);
 145
 146                         if (b < 0)
 147                                 return (-1);
 148                         handle->_sections[i] = msg;
 149                         msg += b;
 150                 }
 151         if (msg != eom)
 152                 goto emsgsize;
 153         handle->_sect = ns_s_max;
 154         handle->_rrnum = -1;
 155         handle->_msg_ptr = NULL;
 156         return (0);
 157  emsgsize:
 158         errno = EMSGSIZE;
 159         return (-1);
 160 }
 161
 162 int
 163 ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) {
 164         int b;
 165
 166         /* Make section right. */
 167         if (section < 0 || section >= ns_s_max)
 168                 goto enodev;
 169         if ((int)section != (int)handle->_sect) {
 170                 handle->_sect = section;
 171                 handle->_rrnum = 0;
 172                 handle->_msg_ptr = handle->_sections[(int)section];
 173         }
 174
 175         /* Make rrnum right. */
 176         if (rrnum == -1)
 177                 rrnum = handle->_rrnum;
 178         if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
 179                 goto enodev;
 180         if (rrnum < handle->_rrnum) {
 181                 handle->_rrnum = 0;
 182                 handle->_msg_ptr = handle->_sections[(int)section];
 183         }
 184
 185         b = skiprr(handle->_msg, handle->_eom, section,
 186                    rrnum - handle->_rrnum);
 187         if (b < 0)
 188                 return (-1);
 189         handle->_msg_ptr += b;
 190         handle->_rrnum = rrnum;
 191
 192         /* Do the parse. */
 193         b = dn_expand(handle->_msg, handle->_eom,
 194                       handle->_msg_ptr, rr->name, NS_MAXDNAME);
 195         if (b < 0)
 196                 return (-1);
 197         handle->_msg_ptr += b;
 198         if (handle->_msg_ptr + NS_INT16SZ > handle->_eom)
 199                 goto emsgsize;
 200         NS_GET16(rr->type, handle->_msg_ptr);
 201         if (handle->_msg_ptr + NS_INT16SZ > handle->_eom)
 202                 goto emsgsize;
 203         NS_GET16(rr->rr_class, handle->_msg_ptr);
 204         if (section == ns_s_qd) {
 205                 rr->ttl = 0;
 206                 rr->rdlength = 0;
 207                 rr->rdata = NULL;
 208         } else {
 209                 if (handle->_msg_ptr + NS_INT32SZ > handle->_eom)
 210                         goto emsgsize;
 211                 NS_GET32(rr->ttl, handle->_msg_ptr);
 212                 if (handle->_msg_ptr + NS_INT16SZ > handle->_eom)
 213                         goto emsgsize;
 214                 NS_GET16(rr->rdlength, handle->_msg_ptr);
 215                 if (handle->_msg_ptr + rr->rdlength > handle->_eom)
 216                         goto emsgsize;
 217                 rr->rdata = handle->_msg_ptr;
 218                 handle->_msg_ptr += rr->rdlength;
 219         }
 220         handle->_rrnum++;
 221
 222         /* All done. */
 223         return (0);
 224  enodev:
 225         errno = ENODEV;
 226         return (-1);
 227  emsgsize:
 228         errno = EMSGSIZE;
 229         return (-1);
 230 }