Merge internal change: 132864057

net/quic/core/quic_connection.cc

Index: net/quic/core/quic_connection.cc
diff --git a/net/quic/core/quic_connection.cc b/net/quic/core/quic_connection.cc
index 734740cf849bdbb5d704c240fe8d5a5d5441326c..134a7ece2f70d39371e11cb7c9917758e4a6d5ac 100644
--- a/net/quic/core/quic_connection.cc
+++ b/net/quic/core/quic_connection.cc
@@ -1404,10 +1404,31 @@ bool QuicConnection::ProcessValidatedPacket(const QuicPacketHeader& header) {
       IsInitializedIPEndPoint(self_address_) &&
       IsInitializedIPEndPoint(last_packet_destination_address_) &&
       (!(self_address_ == last_packet_destination_address_))) {
-    CloseConnection(QUIC_ERROR_MIGRATING_ADDRESS,
-                    "Self address migration is not supported at the server.",
-                    ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
-    return false;
+    if (!FLAGS_quic_allow_server_address_change_for_mapped_ipv4) {
+      CloseConnection(QUIC_ERROR_MIGRATING_ADDRESS,
+                      "Self address migration is not supported at the server.",
+                      ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
+      return false;
+    }
+    // Allow change between pure IPv4 and equivalent mapped IPv4 address.
+    IPAddress self_ip = self_address_.address();
+    if (self_ip.IsIPv4MappedIPv6()) {
+      self_ip = ConvertIPv4MappedIPv6ToIPv4(self_ip);
+    }
+    IPAddress last_packet_destination_ip =
+        last_packet_destination_address_.address();
+    if (last_packet_destination_ip.IsIPv4MappedIPv6()) {
+      last_packet_destination_ip =
+          ConvertIPv4MappedIPv6ToIPv4(last_packet_destination_ip);
+    }
+    if (self_address_.port() != last_packet_destination_address_.port() ||
+        self_ip != last_packet_destination_ip) {
+      CloseConnection(QUIC_ERROR_MIGRATING_ADDRESS,
+                      "Self address migration is not supported at the server.",
+                      ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
+      return false;
+    }
+    self_address_ = last_packet_destination_address_;
   }
 
   if (!Near(header.packet_number, last_header_.packet_number)) {