dlls/dnsapi/ns_parse.c

   1 /*
   2  * Copyright (c) 1996,1999 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 #include "config.h"
  19
  20 #ifdef HAVE_RESOLV
  21
  22 #include <sys/types.h>
  23
  24 #ifdef HAVE_NETINET_IN_H
  25 # include <netinet/in.h>
  26 #endif
  27 #ifdef HAVE_ARPA_NAMESER_H
  28 # include <arpa/nameser.h>
  29 #endif
  30
  31 #include <errno.h>
  32 #ifdef HAVE_RESOLV_H
  33 # include <resolv.h>
  34 #endif
  35 #include <stdarg.h>
  36 #include <string.h>
  37
  38 #include "windef.h"
  39 #include "winbase.h"
  40 #include "winnls.h"
  41
  42 #include "dnsapi.h"
  43
  44 /* Forward. */
  45
  46 static void     setsection(ns_msg *msg, ns_sect sect);
  47
  48 /* Macros. */
  49
  50 #define RETERR(err) do { return (-1); } while (0)
  51
  52 #ifdef HAVE_NS_MSG__MSG_PTR
  53 # define NS_PTR(ns_msg) ((ns_msg)->_msg_ptr)
  54 #else
  55 # define NS_PTR(ns_msg) ((ns_msg)->_ptr)
  56 #endif
  57
  58 #define DNS_NS_GET16(s, cp) do { \
  59     register const u_char *t_cp = (cp); \
  60     (s) = ((WORD)t_cp[0] << 8) \
  61         | ((WORD)t_cp[1]) \
  62         ; \
  63     (cp) += NS_INT16SZ; \
  64 } while (0)
  65
  66 #define DNS_NS_GET32(l, cp) do { \
  67     register const u_char *t_cp = (cp); \
  68     (l) = ((DWORD)t_cp[0] << 24) \
  69         | ((DWORD)t_cp[1] << 16) \
  70         | ((DWORD)t_cp[2] << 8) \
  71         | ((DWORD)t_cp[3]) \
  72         ; \
  73     (cp) += NS_INT32SZ; \
  74 } while (0)
  75
  76 /* Public. */
  77
  78 static int
  79 dns_ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) {
  80         const u_char *optr = ptr;
  81
  82         while (count-- > 0) {
  83                 int rdlength;
  84
  85                 if (dns_ns_name_skip(&ptr, eom) < 0)
  86                         RETERR(EMSGSIZE);
  87                 ptr += NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
  88                 if (section != ns_s_qd) {
  89                         if (ptr + NS_INT32SZ + NS_INT16SZ > eom)
  90                                 RETERR(EMSGSIZE);
  91                         ptr += NS_INT32SZ/*TTL*/;
  92                         DNS_NS_GET16(rdlength, ptr);
  93                         ptr += rdlength/*RData*/;
  94                 }
  95         }
  96         if (ptr > eom)
  97                 RETERR(EMSGSIZE);
  98         return (ptr - optr);
  99 }
 100
 101 int
 102 dns_ns_initparse(const u_char *msg, int msglen, ns_msg *handle) {
 103         const u_char *eom = msg + msglen;
 104         int i;
 105
 106         memset(handle, 0x5e, sizeof *handle);
 107         handle->_msg = msg;
 108         handle->_eom = eom;
 109         if (msg + NS_INT16SZ > eom)
 110                 RETERR(EMSGSIZE);
 111         DNS_NS_GET16(handle->_id, msg);
 112         if (msg + NS_INT16SZ > eom)
 113                 RETERR(EMSGSIZE);
 114         DNS_NS_GET16(handle->_flags, msg);
 115         for (i = 0; i < ns_s_max; i++) {
 116                 if (msg + NS_INT16SZ > eom)
 117                         RETERR(EMSGSIZE);
 118                 DNS_NS_GET16(handle->_counts[i], msg);
 119         }
 120         for (i = 0; i < ns_s_max; i++)
 121                 if (handle->_counts[i] == 0)
 122                         handle->_sections[i] = NULL;
 123                 else {
 124                         int b = dns_ns_skiprr(msg, eom, (ns_sect)i,
 125                                           handle->_counts[i]);
 126
 127                         if (b < 0)
 128                                 return (-1);
 129                         handle->_sections[i] = msg;
 130                         msg += b;
 131                 }
 132         if (msg != eom)
 133                 RETERR(EMSGSIZE);
 134         setsection(handle, ns_s_max);
 135         return (0);
 136 }
 137
 138 int
 139 dns_ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) {
 140         int b;
 141
 142         /* Make section right. */
 143         if (section >= ns_s_max)
 144                 RETERR(ENODEV);
 145         if (section != handle->_sect)
 146                 setsection(handle, section);
 147
 148         /* Make rrnum right. */
 149         if (rrnum == -1)
 150                 rrnum = handle->_rrnum;
 151         if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
 152                 RETERR(ENODEV);
 153         if (rrnum < handle->_rrnum)
 154                 setsection(handle, section);
 155         if (rrnum > handle->_rrnum) {
 156                 b = dns_ns_skiprr(NS_PTR(handle), handle->_eom, section,
 157                               rrnum - handle->_rrnum);
 158
 159                 if (b < 0)
 160                         return (-1);
 161                 NS_PTR(handle) += b;
 162                 handle->_rrnum = rrnum;
 163         }
 164
 165         /* Do the parse. */
 166         b = dn_expand(handle->_msg, handle->_eom,
 167                       NS_PTR(handle), rr->name, NS_MAXDNAME);
 168         if (b < 0)
 169                 return (-1);
 170         NS_PTR(handle) += b;
 171         if (NS_PTR(handle) + NS_INT16SZ + NS_INT16SZ > handle->_eom)
 172                 RETERR(EMSGSIZE);
 173         DNS_NS_GET16(rr->type, NS_PTR(handle));
 174         DNS_NS_GET16(rr->rr_class, NS_PTR(handle));
 175         if (section == ns_s_qd) {
 176                 rr->ttl = 0;
 177                 rr->rdlength = 0;
 178                 rr->rdata = NULL;
 179         } else {
 180                 if (NS_PTR(handle) + NS_INT32SZ + NS_INT16SZ > handle->_eom)
 181                         RETERR(EMSGSIZE);
 182                 DNS_NS_GET32(rr->ttl, NS_PTR(handle));
 183                 DNS_NS_GET16(rr->rdlength, NS_PTR(handle));
 184                 if (NS_PTR(handle) + rr->rdlength > handle->_eom)
 185                         RETERR(EMSGSIZE);
 186                 rr->rdata = NS_PTR(handle);
 187                 NS_PTR(handle) += rr->rdlength;
 188         }
 189         if (++handle->_rrnum > handle->_counts[(int)section])
 190                 setsection(handle, (ns_sect)((int)section + 1));
 191
 192         /* All done. */
 193         return (0);
 194 }
 195
 196 /* Private. */
 197
 198 static void
 199 setsection(ns_msg *msg, ns_sect sect) {
 200         msg->_sect = sect;
 201         if (sect == ns_s_max) {
 202                 msg->_rrnum = -1;
 203                 NS_PTR(msg) = NULL;
 204         } else {
 205                 msg->_rrnum = 0;
 206                 NS_PTR(msg) = msg->_sections[(int)sect];
 207         }
 208 }
 209
 210 #endif