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 #include <sys/types.h>
  21
  22 #ifdef HAVE_NETINET_IN_H
  23 # include <netinet/in.h>
  24 #endif
  25 #ifdef HAVE_ARPA_NAMESER_H
  26 # include <arpa/nameser.h>
  27 #endif
  28
  29 #include <errno.h>
  30 #ifdef HAVE_RESOLV_H
  31 # include <resolv.h>
  32 #endif
  33 #include <string.h>
  34
  35 /* Forward. */
  36
  37 static void     setsection(ns_msg *msg, ns_sect sect);
  38
  39 /* Macros. */
  40
  41 #define RETERR(err) do { return (-1); } while (0)
  42
  43 #ifdef HAVE_NS_MSG__MSG_PTR
  44 # define NS_PTR(ns_msg) ((ns_msg)->_msg_ptr)
  45 #else
  46 # define NS_PTR(ns_msg) ((ns_msg)->_ptr)
  47 #endif
  48
  49 /* Public. */
  50
  51 static int
  52 dns_ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) {
  53         const u_char *optr = ptr;
  54
  55         for ((void)NULL; count > 0; count--) {
  56                 int b, rdlength;
  57
  58                 b = dn_skipname(ptr, eom);
  59                 if (b < 0)
  60                         RETERR(EMSGSIZE);
  61                 ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
  62                 if (section != ns_s_qd) {
  63                         if (ptr + NS_INT32SZ + NS_INT16SZ > eom)
  64                                 RETERR(EMSGSIZE);
  65                         ptr += NS_INT32SZ/*TTL*/;
  66                         NS_GET16(rdlength, ptr);
  67                         ptr += rdlength/*RData*/;
  68                 }
  69         }
  70         if (ptr > eom)
  71                 RETERR(EMSGSIZE);
  72         return (ptr - optr);
  73 }
  74
  75 int
  76 dns_ns_initparse(const u_char *msg, int msglen, ns_msg *handle) {
  77         const u_char *eom = msg + msglen;
  78         int i;
  79
  80         memset(handle, 0x5e, sizeof *handle);
  81         handle->_msg = msg;
  82         handle->_eom = eom;
  83         if (msg + NS_INT16SZ > eom)
  84                 RETERR(EMSGSIZE);
  85         NS_GET16(handle->_id, msg);
  86         if (msg + NS_INT16SZ > eom)
  87                 RETERR(EMSGSIZE);
  88         NS_GET16(handle->_flags, msg);
  89         for (i = 0; i < ns_s_max; i++) {
  90                 if (msg + NS_INT16SZ > eom)
  91                         RETERR(EMSGSIZE);
  92                 NS_GET16(handle->_counts[i], msg);
  93         }
  94         for (i = 0; i < ns_s_max; i++)
  95                 if (handle->_counts[i] == 0)
  96                         handle->_sections[i] = NULL;
  97                 else {
  98                         int b = dns_ns_skiprr(msg, eom, (ns_sect)i,
  99                                           handle->_counts[i]);
 100
 101                         if (b < 0)
 102                                 return (-1);
 103                         handle->_sections[i] = msg;
 104                         msg += b;
 105                 }
 106         if (msg != eom)
 107                 RETERR(EMSGSIZE);
 108         setsection(handle, ns_s_max);
 109         return (0);
 110 }
 111
 112 int
 113 dns_ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) {
 114         int b;
 115
 116         /* Make section right. */
 117         if (section < 0 || section >= ns_s_max)
 118                 RETERR(ENODEV);
 119         if (section != handle->_sect)
 120                 setsection(handle, section);
 121
 122         /* Make rrnum right. */
 123         if (rrnum == -1)
 124                 rrnum = handle->_rrnum;
 125         if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
 126                 RETERR(ENODEV);
 127         if (rrnum < handle->_rrnum)
 128                 setsection(handle, section);
 129         if (rrnum > handle->_rrnum) {
 130                 b = dns_ns_skiprr(NS_PTR(handle), handle->_eom, section,
 131                               rrnum - handle->_rrnum);
 132
 133                 if (b < 0)
 134                         return (-1);
 135                 NS_PTR(handle) += b;
 136                 handle->_rrnum = rrnum;
 137         }
 138
 139         /* Do the parse. */
 140         b = dn_expand(handle->_msg, handle->_eom,
 141                       NS_PTR(handle), rr->name, NS_MAXDNAME);
 142         if (b < 0)
 143                 return (-1);
 144         NS_PTR(handle) += b;
 145         if (NS_PTR(handle) + NS_INT16SZ + NS_INT16SZ > handle->_eom)
 146                 RETERR(EMSGSIZE);
 147         NS_GET16(rr->type, NS_PTR(handle));
 148         NS_GET16(rr->rr_class, NS_PTR(handle));
 149         if (section == ns_s_qd) {
 150                 rr->ttl = 0;
 151                 rr->rdlength = 0;
 152                 rr->rdata = NULL;
 153         } else {
 154                 if (NS_PTR(handle) + NS_INT32SZ + NS_INT16SZ > handle->_eom)
 155                         RETERR(EMSGSIZE);
 156                 NS_GET32(rr->ttl, NS_PTR(handle));
 157                 NS_GET16(rr->rdlength, NS_PTR(handle));
 158                 if (NS_PTR(handle) + rr->rdlength > handle->_eom)
 159                         RETERR(EMSGSIZE);
 160                 rr->rdata = NS_PTR(handle);
 161                 NS_PTR(handle) += rr->rdlength;
 162         }
 163         if (++handle->_rrnum > handle->_counts[(int)section])
 164                 setsection(handle, (ns_sect)((int)section + 1));
 165
 166         /* All done. */
 167         return (0);
 168 }
 169
 170 /* Private. */
 171
 172 static void
 173 setsection(ns_msg *msg, ns_sect sect) {
 174         msg->_sect = sect;
 175         if (sect == ns_s_max) {
 176                 msg->_rrnum = -1;
 177                 NS_PTR(msg) = NULL;
 178         } else {
 179                 msg->_rrnum = 0;
 180                 NS_PTR(msg) = msg->_sections[(int)sect];
 181         }
 182 }