Auto merge of #2919 - bitcartel:2904_branch_id_protocol_handshake, r=str4d

Overwinter peer management

Implements ZIP 201.

Part of #2904.

qa/pull-tester/rpc-tests.sh

@@ -51,6 +51,7 @@ testScripts=(
     'getblocktemplate.py'
     'bip65-cltv-p2p.py'
     'bipdersig-p2p.py'
+    'overwinter_peer_management.py'
 );
 testScriptsExt=(
     'getblocktemplate_longpoll.py'

qa/rpc-tests/overwinter_peer_management.py

@@ -0,0 +1,117 @@
+#!/usr/bin/env python2
+# Copyright (c) 2018 The Zcash developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+from test_framework.mininode import NodeConn, NodeConnCB, NetworkThread, \
+    EarlyDisconnectError, msg_inv, mininode_lock, msg_ping, \
+    MY_VERSION, OVERWINTER_PROTO_VERSION
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import initialize_chain_clean, start_nodes, \
+    p2p_port, assert_equal
+
+import time
+
+#
+# In this test we connect Sprout and Overwinter mininodes to a Zcashd node
+# which will activate Overwinter at block 10.
+#
+# We test:
+# 1. the mininodes stay connected to Zcash with Sprout consensus rules
+# 2. when Overwinter activates, the Sprout mininodes are dropped
+# 3. new Overwinter nodes can connect to Zcash
+# 4. new Sprout nodes cannot connect to Zcash
+#
+# This test *does not* verify that prior to Overwinter activation, the Zcashd
+# node will prefer connections with Overwinter nodes, with an eviction process
+# that prioritizes Sprout connections.
+#
+
+
+class TestManager(NodeConnCB):
+    def __init__(self):
+        NodeConnCB.__init__(self)
+        self.create_callback_map()
+
+    def on_close(self, conn):
+        pass
+
+    def on_reject(self, conn, message):
+        conn.rejectMessage = message
+
+
+class OverwinterPeerManagementTest(BitcoinTestFramework):
+
+    def setup_chain(self):
+        print "Initializing test directory "+self.options.tmpdir
+        initialize_chain_clean(self.options.tmpdir, 1)
+
+    def setup_network(self):
+        self.nodes = start_nodes(1, self.options.tmpdir,
+                                 extra_args=[['-nuparams=5ba81b19:10', '-debug', '-whitelist=127.0.0.1']])
+
+    def run_test(self):
+        test = TestManager()
+
+        # Launch 10 Sprout and 10 Overwinter mininodes
+        nodes = []
+        for x in xrange(10):
+            nodes.append(NodeConn('127.0.0.1', p2p_port(0), self.nodes[0], test, "regtest", False))
+            nodes.append(NodeConn('127.0.0.1', p2p_port(0), self.nodes[0], test, "regtest", True))
+
+        # Start up network handling in another thread
+        NetworkThread().start()
+
+        # Sprout consensus rules apply at block height 9
+        self.nodes[0].generate(9)
+        assert_equal(9, self.nodes[0].getblockcount())
+
+        # Verify mininodes are still connected to zcashd node
+        peerinfo = self.nodes[0].getpeerinfo()
+        versions = [x["version"] for x in peerinfo]
+        assert_equal(10, versions.count(MY_VERSION))
+        assert_equal(10, versions.count(OVERWINTER_PROTO_VERSION))
+
+        # Overwinter consensus rules activate at block height 10
+        self.nodes[0].generate(1)
+        assert_equal(10, self.nodes[0].getblockcount())
+
+        # Mininodes send ping message to zcashd node.
+        pingCounter = 1
+        for node in nodes:
+            node.send_message(msg_ping(pingCounter))
+            pingCounter = pingCounter + 1
+
+        time.sleep(3)
+
+        # Verify Sprout mininodes have been dropped and Overwinter mininodes are still connected.
+        peerinfo = self.nodes[0].getpeerinfo()
+        versions = [x["version"] for x in peerinfo]
+        assert_equal(0, versions.count(MY_VERSION))
+        assert_equal(10, versions.count(OVERWINTER_PROTO_VERSION))
+
+        # Extend the Overwinter chain with another block.
+        self.nodes[0].generate(1)
+
+        # Connect a new Overwinter mininode to the zcashd node, which is accepted.
+        nodes.append(NodeConn('127.0.0.1', p2p_port(0), self.nodes[0], test, "regtest", True))
+        time.sleep(3)
+        assert_equal(11, len(self.nodes[0].getpeerinfo()))
+
+        # Try to connect a new Sprout mininode to the zcashd node, which is rejected.
+        sprout = NodeConn('127.0.0.1', p2p_port(0), self.nodes[0], test, "regtest", False)
+        nodes.append(sprout)
+        time.sleep(3)
+        assert("Version must be 170003 or greater" in str(sprout.rejectMessage))
+
+        # Verify that only Overwinter mininodes are connected.
+        peerinfo = self.nodes[0].getpeerinfo()
+        versions = [x["version"] for x in peerinfo]
+        assert_equal(0, versions.count(MY_VERSION))
+        assert_equal(11, versions.count(OVERWINTER_PROTO_VERSION))
+
+        for node in nodes:
+            node.disconnect_node()
+
+if __name__ == '__main__':
+    OverwinterPeerManagementTest().main()

qa/rpc-tests/test_framework/mininode.py

@@ -39,6 +39,7 @@ from .equihash import (
     zcash_person,
 )
 
+OVERWINTER_PROTO_VERSION = 170003
 BIP0031_VERSION = 60000
 MY_VERSION = 170002  # past bip-31 for ping/pong
 MY_SUBVERSION = "/python-mininode-tester:0.0.1/"
@@ -868,8 +869,12 @@ class CAlert(object):
 class msg_version(object):
     command = "version"
 
-    def __init__(self):
+    def __init__(self, overwintered=False):
-        self.nVersion = MY_VERSION
+        if overwintered:
+            self.nVersion = OVERWINTER_PROTO_VERSION
+        else:
+            self.nVersion = MY_VERSION
+
         self.nServices = 1
         self.nTime = time.time()
         self.addrTo = CAddress()
@@ -1326,7 +1331,7 @@ class NodeConn(asyncore.dispatcher):
         "regtest": "\xaa\xe8\x3f\x5f"    # regtest
     }
 
-    def __init__(self, dstaddr, dstport, rpc, callback, net="regtest"):
+    def __init__(self, dstaddr, dstport, rpc, callback, net="regtest", overwintered=False):
         asyncore.dispatcher.__init__(self, map=mininode_socket_map)
         self.log = logging.getLogger("NodeConn(%s:%d)" % (dstaddr, dstport))
         self.dstaddr = dstaddr
@@ -1343,7 +1348,7 @@ class NodeConn(asyncore.dispatcher):
         self.disconnect = False
 
         # stuff version msg into sendbuf
-        vt = msg_version()
+        vt = msg_version(overwintered)
         vt.addrTo.ip = self.dstaddr
         vt.addrTo.port = self.dstport
         vt.addrFrom.ip = "0.0.0.0"

src/chainparams.cpp

@@ -95,10 +95,13 @@ public:
         consensus.nPowMaxAdjustDown = 32; // 32% adjustment down
         consensus.nPowMaxAdjustUp = 16; // 16% adjustment up
         consensus.nPowTargetSpacing = 2.5 * 60;
+        consensus.vUpgrades[Consensus::BASE_SPROUT].nProtocolVersion = 170002;
         consensus.vUpgrades[Consensus::BASE_SPROUT].nActivationHeight =
             Consensus::NetworkUpgrade::ALWAYS_ACTIVE;
+        consensus.vUpgrades[Consensus::UPGRADE_TESTDUMMY].nProtocolVersion = 170002;
         consensus.vUpgrades[Consensus::UPGRADE_TESTDUMMY].nActivationHeight =
             Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
+        consensus.vUpgrades[Consensus::UPGRADE_OVERWINTER].nProtocolVersion = 170004;
         consensus.vUpgrades[Consensus::UPGRADE_OVERWINTER].nActivationHeight =
             Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
 
@@ -253,10 +256,13 @@ public:
         consensus.nPowMaxAdjustDown = 32; // 32% adjustment down
         consensus.nPowMaxAdjustUp = 16; // 16% adjustment up
         consensus.nPowTargetSpacing = 2.5 * 60;
+        consensus.vUpgrades[Consensus::BASE_SPROUT].nProtocolVersion = 170002;
         consensus.vUpgrades[Consensus::BASE_SPROUT].nActivationHeight =
             Consensus::NetworkUpgrade::ALWAYS_ACTIVE;
+        consensus.vUpgrades[Consensus::UPGRADE_TESTDUMMY].nProtocolVersion = 170002;
         consensus.vUpgrades[Consensus::UPGRADE_TESTDUMMY].nActivationHeight =
             Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
+        consensus.vUpgrades[Consensus::UPGRADE_OVERWINTER].nProtocolVersion = 170003;
         consensus.vUpgrades[Consensus::UPGRADE_OVERWINTER].nActivationHeight =
             Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
 
@@ -360,10 +366,13 @@ public:
         consensus.nPowMaxAdjustDown = 0; // Turn off adjustment down
         consensus.nPowMaxAdjustUp = 0; // Turn off adjustment up
         consensus.nPowTargetSpacing = 2.5 * 60;
+        consensus.vUpgrades[Consensus::BASE_SPROUT].nProtocolVersion = 170002;
         consensus.vUpgrades[Consensus::BASE_SPROUT].nActivationHeight =
             Consensus::NetworkUpgrade::ALWAYS_ACTIVE;
+        consensus.vUpgrades[Consensus::UPGRADE_TESTDUMMY].nProtocolVersion = 170002;
         consensus.vUpgrades[Consensus::UPGRADE_TESTDUMMY].nActivationHeight =
             Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
+        consensus.vUpgrades[Consensus::UPGRADE_OVERWINTER].nProtocolVersion = 170003;
         consensus.vUpgrades[Consensus::UPGRADE_OVERWINTER].nActivationHeight =
             Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
 

src/consensus/params.h

@@ -28,6 +28,11 @@ enum UpgradeIndex {
 };
 
 struct NetworkUpgrade {
+    /**
+     * The first protocol version which will understand the new consensus rules
+     */
+    int nProtocolVersion;
+
     /**
      * Height of the first block for which the new consensus rules will be active
      */

src/main.cpp

@@ -4721,6 +4721,19 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
             return false;
         }
 
+        // When Overwinter is active, reject incoming connections from non-Overwinter nodes
+        const Consensus::Params& params = Params().GetConsensus();
+        if (NetworkUpgradeActive(GetHeight(), params, Consensus::UPGRADE_OVERWINTER)
+            && pfrom->nVersion < params.vUpgrades[Consensus::UPGRADE_OVERWINTER].nProtocolVersion)
+        {
+            LogPrintf("peer=%d using obsolete version %i; disconnecting\n", pfrom->id, pfrom->nVersion);
+            pfrom->PushMessage("reject", strCommand, REJECT_OBSOLETE,
+                            strprintf("Version must be %d or greater",
+                            params.vUpgrades[Consensus::UPGRADE_OVERWINTER].nProtocolVersion));
+            pfrom->fDisconnect = true;
+            return false;
+        }
+
         if (pfrom->nVersion == 10300)
             pfrom->nVersion = 300;
         if (!vRecv.empty())
@@ -4839,6 +4852,22 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
     }
 
 
+    // Disconnect existing peer connection when:
+    // 1. The version message has been received
+    // 2. Overwinter is active
+    // 3. Peer version is pre-Overwinter
+    else if (NetworkUpgradeActive(GetHeight(), chainparams.GetConsensus(), Consensus::UPGRADE_OVERWINTER)
+            && (pfrom->nVersion < chainparams.GetConsensus().vUpgrades[Consensus::UPGRADE_OVERWINTER].nProtocolVersion))
+    {
+        LogPrintf("peer=%d using obsolete version %i; disconnecting\n", pfrom->id, pfrom->nVersion);
+        pfrom->PushMessage("reject", strCommand, REJECT_OBSOLETE,
+                            strprintf("Version must be %d or greater",
+                            chainparams.GetConsensus().vUpgrades[Consensus::UPGRADE_OVERWINTER].nProtocolVersion));
+        pfrom->fDisconnect = true;
+        return false;
+    }
+
+
     else if (strCommand == "addr")
     {
         vector<CAddress> vAddr;

src/net.cpp

@@ -7,6 +7,7 @@
 #include "config/bitcoin-config.h"
 #endif
 
+#include "main.h"
 #include "net.h"
 
 #include "addrman.h"
@@ -812,6 +813,34 @@ static bool AttemptToEvictConnection(bool fPreferNewConnection) {
 
     // Protect connections with certain characteristics
 
+    // Check version of eviction candidates and prioritize nodes which do not support network upgrade.
+    std::vector<CNodeRef> vTmpEvictionCandidates;
+    int height;
+    {
+        LOCK(cs_main);
+        height = chainActive.Height();
+    }
+
+    const Consensus::Params& params = Params().GetConsensus();
+    int nActivationHeight = params.vUpgrades[Consensus::UPGRADE_OVERWINTER].nActivationHeight;
+
+    if (nActivationHeight > 0 &&
+        height < nActivationHeight &&
+        height >= nActivationHeight - NETWORK_UPGRADE_PEER_PREFERENCE_BLOCK_PERIOD)
+    {
+        // Find any nodes which don't support Overwinter protocol version
+        BOOST_FOREACH(const CNodeRef &node, vEvictionCandidates) {
+            if (node->nVersion < params.vUpgrades[Consensus::UPGRADE_OVERWINTER].nProtocolVersion) {
+                vTmpEvictionCandidates.push_back(node);
+            }
+        }
+
+        // Prioritize these nodes by replacing eviction set with them
+        if (vTmpEvictionCandidates.size() > 0) {
+            vEvictionCandidates = vTmpEvictionCandidates;
+        }
+    }
+
     // Deterministically select 4 peers to protect by netgroup.
     // An attacker cannot predict which netgroups will be protected.
     static CompareNetGroupKeyed comparerNetGroupKeyed;

src/net.h

@@ -57,6 +57,8 @@ static const size_t MAPASKFOR_MAX_SZ = MAX_INV_SZ;
 static const size_t SETASKFOR_MAX_SZ = 2 * MAX_INV_SZ;
 /** The maximum number of peer connections to maintain. */
 static const unsigned int DEFAULT_MAX_PEER_CONNECTIONS = 125;
+/** The period before a network upgrade activates, where connections to upgrading peers are preferred (in blocks). */
+static const int NETWORK_UPGRADE_PEER_PREFERENCE_BLOCK_PERIOD = 24 * 24 * 3;
 
 unsigned int ReceiveFloodSize();
 unsigned int SendBufferSize();

src/version.h

@@ -9,7 +9,7 @@
  * network protocol versioning
  */
 
-static const int PROTOCOL_VERSION = 170002;
+static const int PROTOCOL_VERSION = 170003;
 
 //! initial proto version, to be increased after version/verack negotiation
 static const int INIT_PROTO_VERSION = 209;