1 files changed, 112 insertions, 0 deletions
diff --git a/test/functional/feature_versionbits_warning.py b/test/functional/feature_versionbits_warning.py
new file mode 100755
index 0000000000..2985569a8f
--- /dev/null
+++ b/test/functional/feature_versionbits_warning.py
@@ -0,0 +1,112 @@
+#!/usr/bin/env python3
+# Copyright (c) 2016-2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test version bits warning system.
+
+Generate chains with block versions that appear to be signalling unknown
+soft-forks, and test that warning alerts are generated.
+"""
+import os
+import re
+
+from test_framework.blocktools import create_block, create_coinbase
+from test_framework.messages import msg_block
+from test_framework.mininode import P2PInterface, network_thread_start, mininode_lock
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import wait_until
+
+VB_PERIOD = 144           # versionbits period length for regtest
+VB_THRESHOLD = 108        # versionbits activation threshold for regtest
+VB_TOP_BITS = 0x20000000
+VB_UNKNOWN_BIT = 27       # Choose a bit unassigned to any deployment
+VB_UNKNOWN_VERSION = VB_TOP_BITS | (1 << VB_UNKNOWN_BIT)
+
+WARN_UNKNOWN_RULES_MINED = "Unknown block versions being mined! It's possible unknown rules are in effect"
+WARN_UNKNOWN_RULES_ACTIVE = "unknown new rules activated (versionbit {})".format(VB_UNKNOWN_BIT)
+VB_PATTERN = re.compile("Warning: unknown new rules activated.*versionbit")
+
+class VersionBitsWarningTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.setup_clean_chain = True
+        self.num_nodes = 1
+
+    def setup_network(self):
+        self.alert_filename = os.path.join(self.options.tmpdir, "alert.txt")
+        # Open and close to create zero-length file
+        with open(self.alert_filename, 'w', encoding='utf8'):
+            pass
+        self.extra_args = [["-alertnotify=echo %s >> \"" + self.alert_filename + "\""]]
+        self.setup_nodes()
+
+    def send_blocks_with_version(self, peer, numblocks, version):
+        """Send numblocks blocks to peer with version set"""
+        tip = self.nodes[0].getbestblockhash()
+        height = self.nodes[0].getblockcount()
+        block_time = self.nodes[0].getblockheader(tip)["time"] + 1
+        tip = int(tip, 16)
+
+        for _ in range(numblocks):
+            block = create_block(tip, create_coinbase(height + 1), block_time)
+            block.nVersion = version
+            block.solve()
+            peer.send_message(msg_block(block))
+            block_time += 1
+            height += 1
+            tip = block.sha256
+        peer.sync_with_ping()
+
+    def versionbits_in_alert_file(self):
+        """Test that the versionbits warning has been written to the alert file."""
+        alert_text = open(self.alert_filename, 'r', encoding='utf8').read()
+        return VB_PATTERN.search(alert_text) is not None
+
+    def run_test(self):
+        # Handy alias
+        node = self.nodes[0]
+        node.add_p2p_connection(P2PInterface())
+        network_thread_start()
+        node.p2p.wait_for_verack()
+
+        # Mine one period worth of blocks
+        node.generate(VB_PERIOD)
+
+        self.log.info("Check that there is no warning if previous VB_BLOCKS have <VB_THRESHOLD blocks with unknown versionbits version.")
+        # Build one period of blocks with < VB_THRESHOLD blocks signaling some unknown bit
+        self.send_blocks_with_version(node.p2p, VB_THRESHOLD - 1, VB_UNKNOWN_VERSION)
+        node.generate(VB_PERIOD - VB_THRESHOLD + 1)
+
+        # Check that we're not getting any versionbit-related errors in get*info()
+        assert(not VB_PATTERN.match(node.getmininginfo()["warnings"]))
+        assert(not VB_PATTERN.match(node.getnetworkinfo()["warnings"]))
+
+        self.log.info("Check that there is a warning if >50 blocks in the last 100 were an unknown version")
+        # Build one period of blocks with VB_THRESHOLD blocks signaling some unknown bit
+        self.send_blocks_with_version(node.p2p, VB_THRESHOLD, VB_UNKNOWN_VERSION)
+        node.generate(VB_PERIOD - VB_THRESHOLD)
+
+        # Check that get*info() shows the 51/100 unknown block version error.
+        assert(WARN_UNKNOWN_RULES_MINED in node.getmininginfo()["warnings"])
+        assert(WARN_UNKNOWN_RULES_MINED in node.getnetworkinfo()["warnings"])
+
+        self.log.info("Check that there is a warning if previous VB_BLOCKS have >=VB_THRESHOLD blocks with unknown versionbits version.")
+        # Mine a period worth of expected blocks so the generic block-version warning
+        # is cleared. This will move the versionbit state to ACTIVE.
+        node.generate(VB_PERIOD)
+
+        # Stop-start the node. This is required because bitcoind will only warn once about unknown versions or unknown rules activating.
+        self.restart_node(0)
+
+        # Generating one block guarantees that we'll get out of IBD
+        node.generate(1)
+        wait_until(lambda: not node.getblockchaininfo()['initialblockdownload'], timeout=10, lock=mininode_lock)
+        # Generating one more block will be enough to generate an error.
+        node.generate(1)
+        # Check that get*info() shows the versionbits unknown rules warning
+        assert(WARN_UNKNOWN_RULES_ACTIVE in node.getmininginfo()["warnings"])
+        assert(WARN_UNKNOWN_RULES_ACTIVE in node.getnetworkinfo()["warnings"])
+        # Check that the alert file shows the versionbits unknown rules warning
+        wait_until(lambda: self.versionbits_in_alert_file(), timeout=60)
+
+if __name__ == '__main__':
+    VersionBitsWarningTest().main()