Merge #11740: Implement BIP159 NODE_NETWORK_LIMITED (pruned peers) *signaling only*

de74c62 [Doc] Update bip.md, add support for BIP 159 (Jonas Schnelli)
e054d0e [QA] Add node_network_limited test (Jonas Schnelli)
bd09416 Avoid leaking the prune height through getdata (fingerprinting countermeasure) (Jonas Schnelli)
27df193 Always set NODE_NETWORK_LIMITED bit (Jonas Schnelli)
7caba38 Add NODE_NETWORK_LIMITED flags and min block amount constants (Jonas Schnelli)

Pull request description:

  Extracted from #10387.
  Does implement BIP159, but only the signalling part. No connections are made to NODE_NETWORK_LIMITED in this PR.

  The address relay and connection work (the more complicated part) can then be separated (probably in #10387).

Tree-SHA512: e3218eb4789a9320b0f42dc10f62d30c13c49bdef00443fbe653bee22933477adcfc1cf8f6a95269324560b5721203ed41f3c5e2dd8a98ec2791f6a9d8346b1a

2 files changed, 82 insertions, 0 deletions

diff --git a/test/functional/node_network_limited.py b/test/functional/node_network_limited.py
new file mode 100755
index 0000000000..6d1bf7ced2
--- /dev/null
+++ b/test/functional/node_network_limited.py
@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+# Copyright (c) 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.
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import *
+from test_framework.mininode import *
+
+class BaseNode(P2PInterface):
+    nServices = 0
+    firstAddrnServices = 0
+    def on_version(self, message):
+        self.nServices = message.nServices
+
+class NodeNetworkLimitedTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.setup_clean_chain = True
+        self.num_nodes = 1
+        self.extra_args = [['-prune=550']]
+
+    def getSignaledServiceFlags(self):
+        node = self.nodes[0].add_p2p_connection(BaseNode())
+        NetworkThread().start()
+        node.wait_for_verack()
+        services = node.nServices
+        self.nodes[0].disconnect_p2ps()
+        node.wait_for_disconnect()
+        return services
+
+    def tryGetBlockViaGetData(self, blockhash, must_disconnect):
+        node = self.nodes[0].add_p2p_connection(BaseNode())
+        NetworkThread().start()
+        node.wait_for_verack()
+        node.send_message(msg_verack())
+        getdata_request = msg_getdata()
+        getdata_request.inv.append(CInv(2, int(blockhash, 16)))
+        node.send_message(getdata_request)
+
+        if (must_disconnect):
+            #ensure we get disconnected
+            node.wait_for_disconnect(5)
+        else:
+            # check if the peer sends us the requested block
+            node.wait_for_block(int(blockhash, 16), 3)
+            self.nodes[0].disconnect_p2ps()
+            node.wait_for_disconnect()
+
+    def run_test(self):
+        #NODE_BLOOM & NODE_WITNESS & NODE_NETWORK_LIMITED must now be signaled
+        assert_equal(self.getSignaledServiceFlags(), 1036) #1036 == 0x40C == 0100 0000 1100
+#                                                                              |        ||
+#                                                                              |        |^--- NODE_BLOOM
+#                                                                              |        ^---- NODE_WITNESS
+#                                                                              ^-- NODE_NETWORK_LIMITED
+
+        #now mine some blocks over the NODE_NETWORK_LIMITED + 2(racy buffer ext.) target
+        firstblock = self.nodes[0].generate(1)[0]
+        blocks = self.nodes[0].generate(292)
+        blockWithinLimitedRange = blocks[-1]
+
+        #make sure we can max retrive block at tip-288
+        #requesting block at height 2 (tip-289) must fail (ignored)
+        self.tryGetBlockViaGetData(firstblock, True) #first block must lead to disconnect
+        self.tryGetBlockViaGetData(blocks[1], False) #last block in valid range
+        self.tryGetBlockViaGetData(blocks[0], True) #first block outside of the 288+2 limit
+
+        #NODE_NETWORK_LIMITED must still be signaled after restart
+        self.restart_node(0)
+        assert_equal(self.getSignaledServiceFlags(), 1036)
+
+        #test the RPC service flags
+        assert_equal(self.nodes[0].getnetworkinfo()['localservices'], "000000000000040c")
+
+        # getdata a block above the NODE_NETWORK_LIMITED threshold must be possible
+        self.tryGetBlockViaGetData(blockWithinLimitedRange, False)
+
+        # getdata a block below the NODE_NETWORK_LIMITED threshold must be ignored
+        self.tryGetBlockViaGetData(firstblock, True)
+
+if __name__ == '__main__':
+    NodeNetworkLimitedTest().main()
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index e38146a79a..58faec521d 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -128,6 +128,7 @@ BASE_SCRIPTS= [
     'uacomment.py',
     'p2p-acceptblock.py',
     'feature_logging.py',
+    'node_network_limited.py',
 ]
 
 EXTENDED_SCRIPTS = [