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