diff --git a/src/net.h b/src/net.h
--- a/src/net.h
+++ b/src/net.h
@@ -1064,8 +1064,10 @@
* Attempts to open a connection. Currently only used from tests.
*
* @param[in] address Address of node to try connecting to
- * @param[in] conn_type ConnectionType::OUTBOUND or
- * ConnectionType::BLOCK_RELAY or ConnectionType::ADDR_FETCH
+ * @param[in] conn_type ConnectionType::OUTBOUND,
+ * ConnectionType::BLOCK_RELAY,
+ * ConnectionType::ADDR_FETCH, or
+ * ConnectionType::FEELER
* @return bool Returns false if there are no available
* slots for this connection:
* - conn_type not a supported ConnectionType
diff --git a/src/net.cpp b/src/net.cpp
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -1310,7 +1310,6 @@
switch (conn_type) {
case ConnectionType::INBOUND:
case ConnectionType::MANUAL:
- case ConnectionType::FEELER:
return false;
case ConnectionType::OUTBOUND_FULL_RELAY:
max_connections = m_max_outbound_full_relay;
@@ -1321,6 +1320,9 @@
// no limit for ADDR_FETCH because -seednode has no limit either
case ConnectionType::ADDR_FETCH:
break;
+ // no limit for FEELER connections since they're short-lived
+ case ConnectionType::FEELER:
+ break;
} // no default case, so the compiler can warn about missing cases
// Count existing connections
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1370,7 +1370,8 @@
: CAddress(CService(), addr.nServices);
CAddress addrMe = CAddress(CService(), nLocalNodeServices);
- const bool tx_relay = !m_ignore_incoming_txs && pnode.m_tx_relay != nullptr;
+ const bool tx_relay = !m_ignore_incoming_txs &&
+ pnode.m_tx_relay != nullptr && !pnode.IsFeelerConn();
m_connman.PushMessage(
&pnode, CNetMsgMaker(INIT_PROTO_VERSION)
.Make(NetMsgType::VERSION, PROTOCOL_VERSION,
diff --git a/src/rpc/net.cpp b/src/rpc/net.cpp
--- a/src/rpc/net.cpp
+++ b/src/rpc/net.cpp
@@ -399,7 +399,7 @@
"The IP address and port to attempt connecting to."},
{"connection_type", RPCArg::Type::STR, RPCArg::Optional::NO,
"Type of connection to open (\"outbound-full-relay\", "
- "\"block-relay-only\" or \"addr-fetch\")."},
+ "\"block-relay-only\", \"addr-fetch\" or \"feeler\")."},
},
RPCResult{RPCResult::Type::OBJ,
"",
@@ -434,6 +434,8 @@
conn_type = ConnectionType::BLOCK_RELAY;
} else if (conn_type_in == "addr-fetch") {
conn_type = ConnectionType::ADDR_FETCH;
+ } else if (conn_type_in == "feeler") {
+ conn_type = ConnectionType::FEELER;
} else {
throw JSONRPCError(RPC_INVALID_PARAMETER, self.ToString());
}
diff --git a/test/functional/p2p_add_connections.py b/test/functional/p2p_add_connections.py
--- a/test/functional/p2p_add_connections.py
+++ b/test/functional/p2p_add_connections.py
@@ -15,6 +15,15 @@
assert_equal(info["connections_out"], num_out)
+class P2PFeelerReceiver(P2PInterface):
+ def on_version(self, message):
+ # The bitcoind node closes feeler connections as soon as a version
+ # message is received from the test framework. Don't send any responses
+ # to the node's version message since the connection will already be
+ # closed.
+ pass
+
+
class P2PAddConnections(BitcoinTestFramework):
def set_test_params(self):
self.num_nodes = 2
@@ -99,6 +108,18 @@
check_node_connections(node=self.nodes[1], num_in=5, num_out=10)
+ self.log.info("Add 1 feeler connection to node 0")
+ feeler_conn = self.nodes[0].add_outbound_p2p_connection(
+ P2PFeelerReceiver(), p2p_idx=6, connection_type="feeler")
+
+ # Feeler connection is closed
+ assert not feeler_conn.is_connected
+
+ # Verify version message received
+ assert_equal(feeler_conn.message_count["version"], 1)
+ # Feeler connections do not request tx relay
+ assert_equal(feeler_conn.last_message["version"].relay, 0)
+
if __name__ == '__main__':
P2PAddConnections().main()
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -722,7 +722,7 @@
def add_outbound_p2p_connection(
self, p2p_conn, *, p2p_idx, connection_type="outbound-full-relay", **kwargs):
"""Add an outbound p2p connection from node. Must be an
- "outbound-full-relay", "block-relay-only" or "addr-fetch" connection.
+ "outbound-full-relay", "block-relay-only", "addr-fetch" or "feeler" connection.
This method adds the p2p connection to the self.p2ps list and returns
the connection to the caller.
@@ -740,11 +740,21 @@
timeout_factor=self.timeout_factor,
**kwargs)()
- p2p_conn.wait_for_connect()
- self.p2ps.append(p2p_conn)
+ if connection_type == "feeler":
+ # feeler connections are closed as soon as the node receives a
+ # `version` message
+ p2p_conn.wait_until(
+ lambda: p2p_conn.message_count["version"] == 1,
+ check_connected=False)
+ p2p_conn.wait_until(
+ lambda: not p2p_conn.is_connected,
+ check_connected=False)
+ else:
+ p2p_conn.wait_for_connect()
+ self.p2ps.append(p2p_conn)
- p2p_conn.wait_for_verack()
- p2p_conn.sync_with_ping()
+ p2p_conn.wait_for_verack()
+ p2p_conn.sync_with_ping()
return p2p_conn