git.oblomov.eu Git - wine/blob - 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 <string.h>
  36
  37 /* Forward. */
  38
  39 static void     setsection(ns_msg *msg, ns_sect sect);
  40
  41 /* Macros. */
  42
  43 #define RETERR(err) do { return (-1); } while (0)
  44
  45 #ifdef HAVE_NS_MSG__MSG_PTR
  46 # define NS_PTR(ns_msg) ((ns_msg)->_msg_ptr)
  47 #else
  48 # define NS_PTR(ns_msg) ((ns_msg)->_ptr)
  49 #endif
  50
  51 #define DNS_NS_GET16(s, cp) do { \
  52     register const u_char *t_cp = (const u_char *)(cp); \
  53     (s) = ((u_int16_t)t_cp[0] << 8) \
  54         | ((u_int16_t)t_cp[1]) \
  55         ; \
  56     (cp) += NS_INT16SZ; \
  57 } while (0)
  58
  59 #define DNS_NS_GET32(l, cp) do { \
  60     register const u_char *t_cp = (const u_char *)(cp); \
  61     (l) = ((u_int32_t)t_cp[0] << 24) \
  62         | ((u_int32_t)t_cp[1] << 16) \
  63         | ((u_int32_t)t_cp[2] << 8) \
  64         | ((u_int32_t)t_cp[3]) \
  65         ; \
  66     (cp) += NS_INT32SZ; \
  67 } while (0)
  68
  69 /* Public. */
  70
  71 static int
  72 dns_ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) {
  73         const u_char *optr = ptr;
  74
  75         for ((void)NULL; count > 0; count--) {
  76                 int b, rdlength;
  77
  78                 b = dn_skipname(ptr, eom);
  79                 if (b < 0)
  80                         RETERR(EMSGSIZE);
  81                 ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
  82                 if (section != ns_s_qd) {
  83                         if (ptr + NS_INT32SZ + NS_INT16SZ > eom)
  84                                 RETERR(EMSGSIZE);
  85                         ptr += NS_INT32SZ/*TTL*/;
  86                         DNS_NS_GET16(rdlength, ptr);
  87                         ptr += rdlength/*RData*/;
  88                 }
  89         }
  90         if (ptr > eom)
  91                 RETERR(EMSGSIZE);
  92         return (ptr - optr);
  93 }
  94
  95 int
  96 dns_ns_initparse(const u_char *msg, int msglen, ns_msg *handle) {
  97         const u_char *eom = msg + msglen;
  98         int i;
  99
 100         memset(handle, 0x5e, sizeof *handle);
 101         handle->_msg = msg;
 102         handle->_eom = eom;
 103         if (msg + NS_INT16SZ > eom)
 104                 RETERR(EMSGSIZE);
 105         DNS_NS_GET16(handle->_id, msg);
 106         if (msg + NS_INT16SZ > eom)
 107                 RETERR(EMSGSIZE);
 108         DNS_NS_GET16(handle->_flags, msg);
 109         for (i = 0; i < ns_s_max; i++) {
 110                 if (msg + NS_INT16SZ > eom)
 111                         RETERR(EMSGSIZE);
 112                 DNS_NS_GET16(handle->_counts[i], msg);
 113         }
 114         for (i = 0; i < ns_s_max; i++)
 115                 if (handle->_counts[i] == 0)
 116                         handle->_sections[i] = NULL;
 117                 else {
 118                         int b = dns_ns_skiprr(msg, eom, (ns_sect)i,
 119                                           handle->_counts[i]);
 120
 121                         if (b < 0)
 122                                 return (-1);
 123                         handle->_sections[i] = msg;
 124                         msg += b;
 125                 }
 126         if (msg != eom)
 127                 RETERR(EMSGSIZE);
 128         setsection(handle, ns_s_max);
 129         return (0);
 130 }
 131
 132 int
 133 dns_ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) {
 134         int b;
 135
 136         /* Make section right. */
 137         if (section < 0 || section >= ns_s_max)
 138                 RETERR(ENODEV);
 139         if (section != handle->_sect)
 140                 setsection(handle, section);
 141
 142         /* Make rrnum right. */
 143         if (rrnum == -1)
 144                 rrnum = handle->_rrnum;
 145         if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
 146                 RETERR(ENODEV);
 147         if (rrnum < handle->_rrnum)
 148                 setsection(handle, section);
 149         if (rrnum > handle->_rrnum) {
 150                 b = dns_ns_skiprr(NS_PTR(handle), handle->_eom, section,
 151                               rrnum - handle->_rrnum);
 152
 153                 if (b < 0)
 154                         return (-1);
 155                 NS_PTR(handle) += b;
 156                 handle->_rrnum = rrnum;
 157         }
 158
 159         /* Do the parse. */
 160         b = dn_expand(handle->_msg, handle->_eom,
 161                       NS_PTR(handle), rr->name, NS_MAXDNAME);
 162         if (b < 0)
 163                 return (-1);
 164         NS_PTR(handle) += b;
 165         if (NS_PTR(handle) + NS_INT16SZ + NS_INT16SZ > handle->_eom)
 166                 RETERR(EMSGSIZE);
 167         DNS_NS_GET16(rr->type, NS_PTR(handle));
 168         DNS_NS_GET16(rr->rr_class, NS_PTR(handle));
 169         if (section == ns_s_qd) {
 170                 rr->ttl = 0;
 171                 rr->rdlength = 0;
 172                 rr->rdata = NULL;
 173         } else {
 174                 if (NS_PTR(handle) + NS_INT32SZ + NS_INT16SZ > handle->_eom)
 175                         RETERR(EMSGSIZE);
 176                 DNS_NS_GET32(rr->ttl, NS_PTR(handle));
 177                 DNS_NS_GET16(rr->rdlength, NS_PTR(handle));
 178                 if (NS_PTR(handle) + rr->rdlength > handle->_eom)
 179                         RETERR(EMSGSIZE);
 180                 rr->rdata = NS_PTR(handle);
 181                 NS_PTR(handle) += rr->rdlength;
 182         }
 183         if (++handle->_rrnum > handle->_counts[(int)section])
 184                 setsection(handle, (ns_sect)((int)section + 1));
 185
 186         /* All done. */
 187         return (0);
 188 }
 189
 190 /* Private. */
 191
 192 static void
 193 setsection(ns_msg *msg, ns_sect sect) {
 194         msg->_sect = sect;
 195         if (sect == ns_s_max) {
 196                 msg->_rrnum = -1;
 197                 NS_PTR(msg) = NULL;
 198         } else {
 199                 msg->_rrnum = 0;
 200                 NS_PTR(msg) = msg->_sections[(int)sect];
 201         }
 202 }
 203
 204 #endif