test: Functional test for opportunistic encryption

Co-authored-by: Pieter Wuille <bitcoin-dev@wuille.net>

3 files changed, 121 insertions, 13 deletions

diff --git a/src/net.cpp b/src/net.cpp
index a3792b7d49..6b2ef5f43d 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -1552,6 +1552,10 @@ void V2Transport::MarkBytesSent(size_t bytes_sent) noexcept
     LOCK(m_send_mutex);
     if (m_send_state == SendState::V1) return m_v1_fallback.MarkBytesSent(bytes_sent);
 
+    if (m_send_state == SendState::AWAITING_KEY && m_send_pos == 0 && bytes_sent > 0) {
+        LogPrint(BCLog::NET, "start sending v2 handshake to peer=%d\n", m_nodeid);
+    }
+
     m_send_pos += bytes_sent;
     Assume(m_send_pos <= m_send_buffer.size());
     if (m_send_pos >= CMessageHeader::HEADER_SIZE) {
diff --git a/test/functional/p2p_v2_transport.py b/test/functional/p2p_v2_transport.py
index 9df4c297e4..2455bf2e2d 100755
--- a/test/functional/p2p_v2_transport.py
+++ b/test/functional/p2p_v2_transport.py
@@ -12,19 +12,116 @@ from test_framework.util import assert_equal
 
 class V2TransportTest(BitcoinTestFramework):
     def set_test_params(self):
-        self.setup_clean_chain=True
-        self.num_nodes = 1
-        self.extra_args = [["-v2transport=0"]]
+        self.setup_clean_chain = True
+        self.num_nodes = 5
+        self.extra_args = [["-v2transport=1"], ["-v2transport=1"], ["-v2transport=0"], ["-v2transport=0"], ["-v2transport=0"]]
 
     def run_test(self):
-        network_info = self.nodes[0].getnetworkinfo()
+        sending_handshake = "start sending v2 handshake to peer"
+        downgrading_to_v1 = "retrying with v1 transport protocol for peer"
+        self.disconnect_nodes(0, 1)
+        self.disconnect_nodes(1, 2)
+        self.disconnect_nodes(2, 3)
+        self.disconnect_nodes(3, 4)
+
+        # verify local services
+        network_info = self.nodes[2].getnetworkinfo()
         assert_equal(int(network_info["localservices"], 16) & NODE_P2P_V2, 0)
         assert "P2P_V2" not in network_info["localservicesnames"]
-
-        self.restart_node(0, ["-v2transport=1"])
-        network_info = self.nodes[0].getnetworkinfo()
+        network_info = self.nodes[1].getnetworkinfo()
         assert_equal(int(network_info["localservices"], 16) & NODE_P2P_V2, NODE_P2P_V2)
         assert "P2P_V2" in network_info["localservicesnames"]
 
+        # V2 nodes can sync with V2 nodes
+        assert_equal(self.nodes[0].getblockcount(), 0)
+        assert_equal(self.nodes[1].getblockcount(), 0)
+        with self.nodes[0].assert_debug_log(expected_msgs=[sending_handshake],
+                                            unexpected_msgs=[downgrading_to_v1]):
+            self.connect_nodes(0, 1, peer_advertises_v2=True)
+        self.generate(self.nodes[0], 5, sync_fun=lambda: self.sync_all(self.nodes[0:2]))
+        assert_equal(self.nodes[1].getblockcount(), 5)
+        # verify there is a v2 connection between node 0 and 1
+        node_0_info = self.nodes[0].getpeerinfo()
+        node_1_info = self.nodes[0].getpeerinfo()
+        assert_equal(len(node_0_info), 1)
+        assert_equal(len(node_1_info), 1)
+        assert_equal(node_0_info[0]["transport_protocol_type"], "v2")
+        assert_equal(node_1_info[0]["transport_protocol_type"], "v2")
+        assert_equal(len(node_0_info[0]["session_id"]), 64)
+        assert_equal(len(node_1_info[0]["session_id"]), 64)
+        assert_equal(node_0_info[0]["session_id"], node_1_info[0]["session_id"])
+
+        # V1 nodes can sync with each other
+        assert_equal(self.nodes[2].getblockcount(), 0)
+        assert_equal(self.nodes[3].getblockcount(), 0)
+        with self.nodes[2].assert_debug_log(expected_msgs=[],
+                                            unexpected_msgs=[sending_handshake, downgrading_to_v1]):
+            self.connect_nodes(2, 3, peer_advertises_v2=False)
+        self.generate(self.nodes[2], 8, sync_fun=lambda: self.sync_all(self.nodes[2:4]))
+        assert_equal(self.nodes[3].getblockcount(), 8)
+        assert self.nodes[0].getbestblockhash() != self.nodes[2].getbestblockhash()
+        # verify there is a v1 connection between node 2 and 3
+        node_2_info = self.nodes[2].getpeerinfo()
+        node_3_info = self.nodes[3].getpeerinfo()
+        assert_equal(len(node_2_info), 1)
+        assert_equal(len(node_3_info), 1)
+        assert_equal(node_2_info[0]["transport_protocol_type"], "v1")
+        assert_equal(node_3_info[0]["transport_protocol_type"], "v1")
+        assert_equal(len(node_2_info[0]["session_id"]), 0)
+        assert_equal(len(node_3_info[0]["session_id"]), 0)
+
+        # V1 nodes can sync with V2 nodes
+        self.disconnect_nodes(0, 1)
+        self.disconnect_nodes(2, 3)
+        with self.nodes[2].assert_debug_log(expected_msgs=[],
+                                            unexpected_msgs=[sending_handshake, downgrading_to_v1]):
+            self.connect_nodes(2, 1, peer_advertises_v2=False) # cannot enable v2 on v1 node
+        self.sync_all(self.nodes[1:3])
+        assert_equal(self.nodes[1].getblockcount(), 8)
+        assert self.nodes[0].getbestblockhash() != self.nodes[1].getbestblockhash()
+        # verify there is a v1 connection between node 1 and 2
+        node_1_info = self.nodes[1].getpeerinfo()
+        node_2_info = self.nodes[2].getpeerinfo()
+        assert_equal(len(node_1_info), 1)
+        assert_equal(len(node_2_info), 1)
+        assert_equal(node_1_info[0]["transport_protocol_type"], "v1")
+        assert_equal(node_2_info[0]["transport_protocol_type"], "v1")
+        assert_equal(len(node_1_info[0]["session_id"]), 0)
+        assert_equal(len(node_2_info[0]["session_id"]), 0)
+
+        # V2 nodes can sync with V1 nodes
+        self.disconnect_nodes(1, 2)
+        with self.nodes[0].assert_debug_log(expected_msgs=[],
+                                            unexpected_msgs=[sending_handshake, downgrading_to_v1]):
+            self.connect_nodes(0, 3, peer_advertises_v2=False)
+        self.sync_all([self.nodes[0], self.nodes[3]])
+        assert_equal(self.nodes[0].getblockcount(), 8)
+        # verify there is a v1 connection between node 0 and 3
+        node_0_info = self.nodes[0].getpeerinfo()
+        node_3_info = self.nodes[3].getpeerinfo()
+        assert_equal(len(node_0_info), 1)
+        assert_equal(len(node_3_info), 1)
+        assert_equal(node_0_info[0]["transport_protocol_type"], "v1")
+        assert_equal(node_3_info[0]["transport_protocol_type"], "v1")
+        assert_equal(len(node_0_info[0]["session_id"]), 0)
+        assert_equal(len(node_3_info[0]["session_id"]), 0)
+
+        # V2 node mines another block and everyone gets it
+        self.connect_nodes(0, 1, peer_advertises_v2=True)
+        self.connect_nodes(1, 2, peer_advertises_v2=False)
+        self.generate(self.nodes[1], 1, sync_fun=lambda: self.sync_all(self.nodes[0:4]))
+        assert_equal(self.nodes[0].getblockcount(), 9) # sync_all() verifies tip hashes match
+
+        # V1 node mines another block and everyone gets it
+        self.generate(self.nodes[3], 2, sync_fun=lambda: self.sync_all(self.nodes[0:4]))
+        assert_equal(self.nodes[2].getblockcount(), 11) # sync_all() verifies tip hashes match
+
+        assert_equal(self.nodes[4].getblockcount(), 0)
+        # Peer 4 is v1 p2p, but is falsely advertised as v2.
+        with self.nodes[1].assert_debug_log(expected_msgs=[sending_handshake, downgrading_to_v1]):
+            self.connect_nodes(1, 4, peer_advertises_v2=True)
+        self.sync_all()
+        assert_equal(self.nodes[4].getblockcount(), 11)
+
 if __name__ == '__main__':
     V2TransportTest().main()
diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
index 73635b4397..669959dc8a 100755
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -581,13 +581,20 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
     def wait_for_node_exit(self, i, timeout):
         self.nodes[i].process.wait(timeout)
 
-    def connect_nodes(self, a, b):
+    def connect_nodes(self, a, b, *, peer_advertises_v2=False):
         from_connection = self.nodes[a]
         to_connection = self.nodes[b]
         from_num_peers = 1 + len(from_connection.getpeerinfo())
         to_num_peers = 1 + len(to_connection.getpeerinfo())
         ip_port = "127.0.0.1:" + str(p2p_port(b))
-        from_connection.addnode(ip_port, "onetry")
+
+        if peer_advertises_v2:
+            from_connection.addnode(node=ip_port, command="onetry", v2transport=True)
+        else:
+            # skip the optional third argument (default false) for
+            # compatibility with older clients
+            from_connection.addnode(ip_port, "onetry")
+
         # poll until version handshake complete to avoid race conditions
         # with transaction relaying
         # See comments in net_processing:
@@ -595,12 +602,12 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         # * Must have a verack message before anything else
         self.wait_until(lambda: sum(peer['version'] != 0 for peer in from_connection.getpeerinfo()) == from_num_peers)
         self.wait_until(lambda: sum(peer['version'] != 0 for peer in to_connection.getpeerinfo()) == to_num_peers)
-        self.wait_until(lambda: sum(peer['bytesrecv_per_msg'].pop('verack', 0) == 24 for peer in from_connection.getpeerinfo()) == from_num_peers)
-        self.wait_until(lambda: sum(peer['bytesrecv_per_msg'].pop('verack', 0) == 24 for peer in to_connection.getpeerinfo()) == to_num_peers)
+        self.wait_until(lambda: sum(peer['bytesrecv_per_msg'].pop('verack', 0) >= 21 for peer in from_connection.getpeerinfo()) == from_num_peers)
+        self.wait_until(lambda: sum(peer['bytesrecv_per_msg'].pop('verack', 0) >= 21 for peer in to_connection.getpeerinfo()) == to_num_peers)
         # The message bytes are counted before processing the message, so make
         # sure it was fully processed by waiting for a ping.
-        self.wait_until(lambda: sum(peer["bytesrecv_per_msg"].pop("pong", 0) >= 32 for peer in from_connection.getpeerinfo()) == from_num_peers)
-        self.wait_until(lambda: sum(peer["bytesrecv_per_msg"].pop("pong", 0) >= 32 for peer in to_connection.getpeerinfo()) == to_num_peers)
+        self.wait_until(lambda: sum(peer["bytesrecv_per_msg"].pop("pong", 0) >= 29 for peer in from_connection.getpeerinfo()) == from_num_peers)
+        self.wait_until(lambda: sum(peer["bytesrecv_per_msg"].pop("pong", 0) >= 29 for peer in to_connection.getpeerinfo()) == to_num_peers)
 
     def disconnect_nodes(self, a, b):
         def disconnect_nodes_helper(node_a, node_b):