[test] Update p2p_addr_relay test to prepare

Use an init param to make clear whether a getaddr message should be sent when
the P2PConnection receives a version message. These changes are in preparation
for upcoming commits that modify the behavior of a bitcoind node and the test
framework.

test/functional/p2p_addr_relay.py

@@ -11,7 +11,8 @@ from test_framework.messages import (
     NODE_NETWORK,
     NODE_WITNESS,
     msg_addr,
-    msg_getaddr
+    msg_getaddr,
+    msg_verack
 )
 from test_framework.p2p import (
     P2PInterface,
@@ -27,10 +28,12 @@ class AddrReceiver(P2PInterface):
     num_ipv4_received = 0
     test_addr_contents = False
     _tokens = 1
+    send_getaddr = True
 
-    def __init__(self, test_addr_contents=False):
+    def __init__(self, test_addr_contents=False, send_getaddr=True):
         super().__init__()
         self.test_addr_contents = test_addr_contents
+        self.send_getaddr = send_getaddr
 
     def on_addr(self, message):
         for addr in message.addrs:
@@ -60,6 +63,11 @@ class AddrReceiver(P2PInterface):
     def addr_received(self):
         return self.num_ipv4_received != 0
 
+    def on_version(self, message):
+        self.send_message(msg_verack())
+        if (self.send_getaddr):
+            self.send_message(msg_getaddr())
+
     def getaddr_received(self):
         return self.message_count['getaddr'] > 0
 
@@ -156,7 +164,7 @@ class AddrTest(BitcoinTestFramework):
         self.nodes[0].disconnect_p2ps()
 
         self.log.info('Check relay of addresses received from outbound peers')
-        inbound_peer = self.nodes[0].add_p2p_connection(AddrReceiver(test_addr_contents=True))
+        inbound_peer = self.nodes[0].add_p2p_connection(AddrReceiver(test_addr_contents=True, send_getaddr=False))
         full_outbound_peer = self.nodes[0].add_outbound_p2p_connection(AddrReceiver(), p2p_idx=0, connection_type="outbound-full-relay")
         msg = self.setup_addr_msg(2)
         self.send_addr_msg(full_outbound_peer, msg, [inbound_peer])
@@ -185,6 +193,12 @@ class AddrTest(BitcoinTestFramework):
         self.nodes[0].disconnect_p2ps()
 
     def getaddr_tests(self):
+        # In the previous tests, the node answered GETADDR requests with an
+        # empty addrman. Due to GETADDR response caching (see
+        # CConnman::GetAddresses), the node would continue to provide 0 addrs
+        # in response until enough time has passed or the node is restarted.
+        self.restart_node(0)
+
         self.log.info('Test getaddr behavior')
         self.log.info('Check that we send a getaddr message upon connecting to an outbound-full-relay peer')
         full_outbound_peer = self.nodes[0].add_outbound_p2p_connection(AddrReceiver(), p2p_idx=0, connection_type="outbound-full-relay")
@@ -197,7 +211,7 @@ class AddrTest(BitcoinTestFramework):
         assert_equal(block_relay_peer.getaddr_received(), False)
 
         self.log.info('Check that we answer getaddr messages only from inbound peers')
-        inbound_peer = self.nodes[0].add_p2p_connection(AddrReceiver())
+        inbound_peer = self.nodes[0].add_p2p_connection(AddrReceiver(send_getaddr=False))
         inbound_peer.sync_with_ping()
 
         # Add some addresses to addrman