From fad68afcff731153d1c83f7f56c91ecbb264b59a Mon Sep 17 00:00:00 2001 From: MarcoFalke Date: Sun, 4 Oct 2020 17:34:26 +0200 Subject: [PATCH 1/2] p2p: Ignore non-version msgs before version msg Sending a non-version message before the initial version message is peer misbehavior. Though, it seems arbitrary and confusing to disconnect only after exactly 100 non-version messages. So remove the Misbehaving and instead rely on the existing disconnect-due-to-handshake-timeout logic. --- src/net_processing.cpp | 2 +- test/functional/p2p_leak.py | 19 +------------------ test/functional/p2p_timeouts.py | 6 ++++-- 3 files changed, 6 insertions(+), 21 deletions(-) diff --git a/src/net_processing.cpp b/src/net_processing.cpp index c649cf7757c..df97d0e2e7e 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -2477,7 +2477,7 @@ void PeerManager::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDat if (pfrom.nVersion == 0) { // Must have a version message before anything else - Misbehaving(pfrom.GetId(), 1, "non-version message before version handshake"); + LogPrint(BCLog::NET, "non-version message before version handshake. Message \"%s\" from peer=%d\n", SanitizeString(msg_type), pfrom.GetId()); return; } diff --git a/test/functional/p2p_leak.py b/test/functional/p2p_leak.py index 4b32d60db09..ca8bf908a97 100755 --- a/test/functional/p2p_leak.py +++ b/test/functional/p2p_leak.py @@ -24,8 +24,6 @@ from test_framework.util import ( assert_greater_than_or_equal, ) -DISCOURAGEMENT_THRESHOLD = 100 - class LazyPeer(P2PInterface): def __init__(self): @@ -93,27 +91,16 @@ class P2PLeakTest(BitcoinTestFramework): self.num_nodes = 1 def run_test(self): - # Peer that never sends a version. We will send a bunch of messages - # from this peer anyway and verify eventual disconnection. - no_version_disconnect_peer = self.nodes[0].add_p2p_connection( - LazyPeer(), send_version=False, wait_for_verack=False) - # Another peer that never sends a version, nor any other messages. It shouldn't receive anything from the node. no_version_idle_peer = self.nodes[0].add_p2p_connection(LazyPeer(), send_version=False, wait_for_verack=False) # Peer that sends a version but not a verack. no_verack_idle_peer = self.nodes[0].add_p2p_connection(NoVerackIdlePeer(), wait_for_verack=False) - # Send enough ping messages (any non-version message will do) prior to sending - # version to reach the peer discouragement threshold. This should get us disconnected. - for _ in range(DISCOURAGEMENT_THRESHOLD): - no_version_disconnect_peer.send_message(msg_ping()) - # Wait until we got the verack in response to the version. Though, don't wait for the node to receive the # verack, since we never sent one no_verack_idle_peer.wait_for_verack() - no_version_disconnect_peer.wait_until(lambda: no_version_disconnect_peer.ever_connected, check_connected=False) no_version_idle_peer.wait_until(lambda: no_version_idle_peer.ever_connected) no_verack_idle_peer.wait_until(lambda: no_verack_idle_peer.version_received) @@ -123,13 +110,9 @@ class P2PLeakTest(BitcoinTestFramework): #Give the node enough time to possibly leak out a message time.sleep(5) - # Expect this peer to be disconnected for misbehavior - assert not no_version_disconnect_peer.is_connected - self.nodes[0].disconnect_p2ps() # Make sure no unexpected messages came in - assert no_version_disconnect_peer.unexpected_msg == False assert no_version_idle_peer.unexpected_msg == False assert no_verack_idle_peer.unexpected_msg == False @@ -148,7 +131,7 @@ class P2PLeakTest(BitcoinTestFramework): p2p_old_peer = self.nodes[0].add_p2p_connection(P2PInterface(), send_version=False, wait_for_verack=False) old_version_msg = msg_version() old_version_msg.nVersion = 31799 - with self.nodes[0].assert_debug_log(['peer=4 using obsolete version 31799; disconnecting']): + with self.nodes[0].assert_debug_log(['peer=3 using obsolete version 31799; disconnecting']): p2p_old_peer.send_message(old_version_msg) p2p_old_peer.wait_for_disconnect() diff --git a/test/functional/p2p_timeouts.py b/test/functional/p2p_timeouts.py index ce12ce26ced..47832b04bfb 100755 --- a/test/functional/p2p_timeouts.py +++ b/test/functional/p2p_timeouts.py @@ -57,8 +57,10 @@ class TimeoutsTest(BitcoinTestFramework): assert no_version_node.is_connected assert no_send_node.is_connected - no_verack_node.send_message(msg_ping()) - no_version_node.send_message(msg_ping()) + with self.nodes[0].assert_debug_log(['Unsupported message "ping" prior to verack from peer=0']): + no_verack_node.send_message(msg_ping()) + with self.nodes[0].assert_debug_log(['non-version message before version handshake. Message "ping" from peer=1']): + no_version_node.send_message(msg_ping()) sleep(1) From faaad1bbac46cfeb22654b4c59f0aac7a680c03a Mon Sep 17 00:00:00 2001 From: MarcoFalke Date: Mon, 5 Oct 2020 16:21:59 +0200 Subject: [PATCH 2/2] p2p: Ignore version msgs after initial version msg Sending a version message after the intial version message is peer misbehavior. Though, it seems arbitrary and confusing to disconnect only after exactly 100 version messages. Duplicate version messages affect us no different than any other unknown message. So remove the Misbehaving and ignore the redundant msgs. --- src/net_processing.cpp | 6 ++---- test/functional/p2p_invalid_messages.py | 9 +++++++++ 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/src/net_processing.cpp b/src/net_processing.cpp index df97d0e2e7e..f21fb8a49bf 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -2286,10 +2286,8 @@ void PeerManager::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDat if (peer == nullptr) return; if (msg_type == NetMsgType::VERSION) { - // Each connection can only send one version message - if (pfrom.nVersion != 0) - { - Misbehaving(pfrom.GetId(), 1, "redundant version message"); + if (pfrom.nVersion != 0) { + LogPrint(BCLog::NET, "redundant version message from peer=%d\n", pfrom.GetId()); return; } diff --git a/test/functional/p2p_invalid_messages.py b/test/functional/p2p_invalid_messages.py index db72a361d98..c0b3c2cb12e 100755 --- a/test/functional/p2p_invalid_messages.py +++ b/test/functional/p2p_invalid_messages.py @@ -18,6 +18,7 @@ from test_framework.messages import ( msg_inv, msg_ping, MSG_TX, + msg_version, ser_string, ) from test_framework.p2p import ( @@ -60,6 +61,7 @@ class InvalidMessagesTest(BitcoinTestFramework): def run_test(self): self.test_buffer() + self.test_duplicate_version_msg() self.test_magic_bytes() self.test_checksum() self.test_size() @@ -92,6 +94,13 @@ class InvalidMessagesTest(BitcoinTestFramework): conn.sync_with_ping(timeout=1) self.nodes[0].disconnect_p2ps() + def test_duplicate_version_msg(self): + self.log.info("Test duplicate version message is ignored") + conn = self.nodes[0].add_p2p_connection(P2PDataStore()) + with self.nodes[0].assert_debug_log(['redundant version message from peer']): + conn.send_and_ping(msg_version()) + self.nodes[0].disconnect_p2ps() + def test_magic_bytes(self): self.log.info("Test message with invalid magic bytes disconnects peer") conn = self.nodes[0].add_p2p_connection(P2PDataStore())