mDNSMacOSX/DNS64State.h

   1 /*
   2  * Copyright (c) 2017 Apple Inc. All rights reserved.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef __DNS64State_h
  18 #define __DNS64State_h
  19
  20 typedef enum
  21 {
  22     kDNS64State_Initial             = 0,    // Initial state.
  23     kDNS64State_PrefixDiscovery     = 1,    // Querying for "ipv4only.arpa." AAAA records to discover NAT64 IPv6 prefix(es).
  24     kDNS64State_PrefixDiscoveryPTR  = 2,    // Same as PrefixDiscovery, but discoverying for "ip6.arpa." PTR record queries.
  25     kDNS64State_QueryA              = 3,    // Querying for A record with same QNAME as AAAA record query.
  26     kDNS64State_QueryA2             = 4,    // Continuing A record query after being answered with a synthesizable A record.
  27     kDNS64State_QueryAAAA           = 5,    // Querying for original AAAA record.
  28     kDNS64State_QueryPTR            = 6,    // Determining whether to query for reverse IPV4 or reverse IPv6 PTR record.
  29     kDNS64State_ReverseIPv4         = 7,    // Querying for reverse IPV4 (in-addr.arpa.) PTR record.
  30     kDNS64State_ReverseIPv6         = 8     // Querying for the original reverse IPv6 (ip6.arpa.) PTR record.
  31
  32 }   DNS64State;
  33
  34 typedef struct
  35 {
  36     DNS64State      state;          // Current state.
  37     mDNSu8          qnameStash[15]; // Temporary space to hold the up to 15 bytes that are displaced in a DNSQuestion's qname
  38                                     // when it's set to "ipv4only.arpa." during prefix discovery.
  39 }   DNS64;
  40
  41 #endif // __DNS64State_h