On client address changes, only migrate QUIC connections when client address changes are considered…

net/quic/quic_protocol.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_QUIC_QUIC_PROTOCOL_H_
 #define NET_QUIC_QUIC_PROTOCOL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 #include <limits>
@@ skipping 968 matching lines @@
 // to be specified so that it is retransmitted at a level which the peer can
 // understand.
 enum EncryptionLevel {
   ENCRYPTION_NONE = 0,
   ENCRYPTION_INITIAL = 1,
   ENCRYPTION_FORWARD_SECURE = 2,
 
   NUM_ENCRYPTION_LEVELS,
 };
 
+
+enum PeerAddressChangeType {
+  NO_CHANGE,
+  // Peer address changes which are considered to be cause by NATs. Currently,
+  // IPv4 address change with /24 does not change is considered to be cause by
+  // NATs.
+  NAT_PORT_REBINDING,
+  IPV4_SUBNET_REBINDING,
+  // IPv6 related address changes.
+  IPV4_TO_IPV6,
+  IPV6_TO_IPV4,
+  IPV6_TO_IPV6,
+  // This type is used when we always allow peer address changes.
+  UNKNOWN,
+  // All other peer address change types.
+  UNSPECIFIED,
+};
+
 struct NET_EXPORT_PRIVATE QuicFrame {
   QuicFrame();
   explicit QuicFrame(QuicPaddingFrame padding_frame);
   explicit QuicFrame(QuicMtuDiscoveryFrame frame);
   explicit QuicFrame(QuicPingFrame frame);
 
   explicit QuicFrame(QuicStreamFrame* stream_frame);
   explicit QuicFrame(QuicAckFrame* frame);
   explicit QuicFrame(QuicRstStreamFrame* frame);
   explicit QuicFrame(QuicConnectionCloseFrame* frame);
@@ skipping 221 matching lines @@
       : iov(iov), iov_count(iov_count), total_length(total_length) {}
 
   const struct iovec* iov;
   const int iov_count;
   const size_t total_length;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_PROTOCOL_H_