check and penalise td misreporting

- add ErrIncorrectTD
- checkTD called after insertChain successful
- fix tests, use blockPoolTester.tds to map block index to TD

7 files changed, 129 insertions, 52 deletions

diff --git a/blockpool/blockpool.go b/blockpool/blockpool.go
index a552e1b72..df3d14542 100644
--- a/blockpool/blockpool.go
+++ b/blockpool/blockpool.go
@@ -62,6 +62,7 @@ const (
 	ErrUnrequestedBlock
 	ErrInsufficientChainInfo
 	ErrIdleTooLong
+	ErrIncorrectTD
 )
 
 var errorToString = map[int]string{
@@ -70,6 +71,7 @@ var errorToString = map[int]string{
 	ErrUnrequestedBlock:      "Unrequested block",
 	ErrInsufficientChainInfo: "Insufficient chain info",
 	ErrIdleTooLong:           "Idle too long",
+	ErrIncorrectTD:           "Incorrect Total Difficulty",
 }
 
 // init initialises all your laundry
@@ -373,6 +375,7 @@ func (self *BlockPool) AddBlockHashes(next func() (common.Hash, bool), peerId st
 				block:   bestpeer.currentBlock,
 				hashBy:  peerId,
 				blockBy: peerId,
+				td:      bestpeer.td,
 			}
 			// nodes is a list of nodes in one section ordered top-bottom (old to young)
 			nodes = append(nodes, node)
@@ -729,6 +732,17 @@ LOOP:
 	}
 }
 
+func (self *BlockPool) checkTD(nodes ...*node) {
+	for _, n := range nodes {
+		if n.td != nil {
+			plog.DebugDetailf("peer td %v =?= block td %v", n.td, n.block.Td)
+			if n.td.Cmp(n.block.Td) != 0 {
+				self.peers.peerError(n.blockBy, ErrIncorrectTD, "on block %x", n.hash)
+			}
+		}
+	}
+}
+
 // must run in separate go routine, otherwise
 // switchpeer -> activateChain -> activate deadlocks on section process select and peers.lock
 func (self *BlockPool) requestBlocks(attempts int, hashes []common.Hash) {
diff --git a/blockpool/blockpool_test.go b/blockpool/blockpool_test.go
index d8271886f..a76cab9b6 100644
--- a/blockpool/blockpool_test.go
+++ b/blockpool/blockpool_test.go
@@ -51,9 +51,11 @@ func TestPeerPromotionByOptionalTdOnBlock(t *testing.T) {
 	blockPoolTester.initRefBlockChain(4)
 	peer0 := blockPoolTester.newPeer("peer0", 2, 2)
 	peer1 := blockPoolTester.newPeer("peer1", 1, 1)
-	peer2 := blockPoolTester.newPeer("peer2", 3, 4)
+	peer2 := blockPoolTester.newPeer("peer2", 4, 4)
 
 	blockPool.Start()
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[3] = 3
 
 	// pool
 	peer0.AddPeer()
@@ -94,7 +96,7 @@ func TestSimpleChain(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 2)
+	peer1 := blockPoolTester.newPeer("peer1", 2, 2)
 	peer1.AddPeer()
 	peer1.serveBlocks(1, 2)
 	go peer1.serveBlockHashes(2, 1, 0)
@@ -114,7 +116,7 @@ func TestChainConnectingWithParentHash(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer1 := blockPoolTester.newPeer("peer1", 3, 3)
 	peer1.AddPeer()
 	go peer1.serveBlocks(2, 3)
 	go peer1.serveBlockHashes(3, 2, 1)
@@ -134,7 +136,7 @@ func TestMultiSectionChain(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 5)
+	peer1 := blockPoolTester.newPeer("peer1", 5, 5)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(4, 5)
@@ -156,14 +158,16 @@ func TestNewBlocksOnPartialChain(t *testing.T) {
 	blockPoolTester.initRefBlockChain(7)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 5)
+	peer1 := blockPoolTester.newPeer("peer1", 5, 5)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[5] = 5
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(4, 5) // partially complete section
 	go peer1.serveBlockHashes(5, 4, 3)
 	peer1.serveBlocks(3, 4) // partially complete section
 	// peer1 found new blocks
-	peer1.td = 2
+	peer1.td = 7
 	peer1.currentBlock = 7
 	peer1.AddPeer()
 	peer1.sendBlocks(6, 7)
@@ -188,16 +192,15 @@ func TestPeerSwitchUp(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 6)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 7)
+	peer1 := blockPoolTester.newPeer("peer1", 6, 6)
+	peer2 := blockPoolTester.newPeer("peer2", 7, 7)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(5, 6)
 	go peer1.serveBlockHashes(6, 5, 4, 3) //
 	peer1.serveBlocks(2, 3)               // section partially complete, block 3 will be preserved after peer demoted
 	peer2.AddPeer()                       // peer2 is promoted as best peer, peer1 is demoted
-	go peer2.serveBlocks(6, 7)
-	// go peer2.serveBlockHashes(7, 6)       //
+	go peer2.serveBlocks(6, 7)            //
 	go peer2.serveBlocks(4, 5)            // tests that block request for earlier section is remembered
 	go peer1.serveBlocks(3, 4)            // tests that connecting section by demoted peer is remembered and blocks are accepted from demoted peer
 	go peer2.serveBlockHashes(3, 2, 1, 0) // tests that known chain section is activated, hash requests from 3 is remembered
@@ -216,8 +219,8 @@ func TestPeerSwitchDownOverlapSectionWithoutRootBlock(t *testing.T) {
 	blockPoolTester.initRefBlockChain(6)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 4)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	peer1 := blockPoolTester.newPeer("peer1", 4, 4)
+	peer2 := blockPoolTester.newPeer("peer2", 6, 6)
 
 	peer2.AddPeer()
 	peer2.serveBlocks(5, 6)                  // partially complete, section will be preserved
@@ -242,8 +245,8 @@ func TestPeerSwitchDownOverlapSectionWithRootBlock(t *testing.T) {
 	blockPoolTester.initRefBlockChain(6)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 4)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	peer1 := blockPoolTester.newPeer("peer1", 4, 4)
+	peer2 := blockPoolTester.newPeer("peer2", 6, 6)
 
 	peer2.AddPeer()
 	peer2.serveBlocks(5, 6)                  // partially complete, section will be preserved
@@ -269,8 +272,8 @@ func TestPeerSwitchDownDisjointSection(t *testing.T) {
 	blockPoolTester.initRefBlockChain(3)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	peer1 := blockPoolTester.newPeer("peer1", 3, 3)
+	peer2 := blockPoolTester.newPeer("peer2", 6, 6)
 
 	peer2.AddPeer()
 	peer2.serveBlocks(5, 6)            // partially complete, section will be preserved
@@ -297,8 +300,8 @@ func TestPeerSwitchBack(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 2, 11)
-	peer2 := blockPoolTester.newPeer("peer2", 1, 8)
+	peer1 := blockPoolTester.newPeer("peer1", 11, 11)
+	peer2 := blockPoolTester.newPeer("peer2", 8, 8)
 
 	peer2.AddPeer()
 	go peer2.serveBlocks(7, 8)
@@ -328,9 +331,10 @@ func TestForkSimple(t *testing.T) {
 	delete(blockPoolTester.refBlockChain, 6)
 
 	blockPool.Start()
-
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)
@@ -363,9 +367,10 @@ func TestForkSwitchBackByNewBlocks(t *testing.T) {
 	delete(blockPoolTester.refBlockChain, 6)
 
 	blockPool.Start()
-
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)               //
@@ -378,7 +383,7 @@ func TestForkSwitchBackByNewBlocks(t *testing.T) {
 	peer2.serveBlocks(1, 2, 3, 4, 5)         //
 
 	// peer1 finds new blocks
-	peer1.td = 3
+	peer1.td = 11
 	peer1.currentBlock = 11
 	peer1.AddPeer()
 	go peer1.serveBlocks(10, 11)
@@ -410,8 +415,14 @@ func TestForkSwitchBackByPeerSwitchBack(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)
@@ -448,8 +459,11 @@ func TestForkCompleteSectionSwitchBackByPeerSwitchBack(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)
diff --git a/blockpool/blockpool_util_test.go b/blockpool/blockpool_util_test.go
index a17bc584e..f4e5fec2f 100644
--- a/blockpool/blockpool_util_test.go
+++ b/blockpool/blockpool_util_test.go
@@ -40,6 +40,7 @@ type blockPoolTester struct {
 	blockPool         *BlockPool
 	t                 *testing.T
 	chainEvents       *event.TypeMux
+	tds               map[int]int
 }
 
 func newTestBlockPool(t *testing.T) (hashPool *test.TestHashPool, blockPool *BlockPool, b *blockPoolTester) {
@@ -84,6 +85,14 @@ func (self *blockPoolTester) insertChain(blocks types.Blocks) error {
 	var ok bool
 	for _, block := range blocks {
 		child = self.hashPool.HashesToIndexes([]common.Hash{block.Hash()})[0]
+		var td int
+		if self.tds != nil {
+			td, ok = self.tds[child]
+		}
+		if !ok {
+			td = child
+		}
+		block.Td = big.NewInt(int64(td))
 		_, ok = self.blockChain[child]
 		if ok {
 			fmt.Printf("block %v already in blockchain\n", child)
diff --git a/blockpool/errors_test.go b/blockpool/errors_test.go
index 5188930f0..350d6daef 100644
--- a/blockpool/errors_test.go
+++ b/blockpool/errors_test.go
@@ -93,7 +93,6 @@ func TestUnrequestedBlock(t *testing.T) {
 	peer1.AddPeer()
 	peer1.sendBlocks(1, 2)
 
-	// blockPool.Wait(waitTimeout)
 	blockPool.Stop()
 	if len(peer1.peerErrors) == 1 {
 		if peer1.peerErrors[0] != ErrUnrequestedBlock {
@@ -124,6 +123,33 @@ func TestErrInsufficientChainInfo(t *testing.T) {
 	}
 }
 
+func TestIncorrectTD(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPoolTester.blockChain[0] = nil
+	blockPoolTester.initRefBlockChain(3)
+
+	blockPool.Start()
+
+	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer1.AddPeer()
+	go peer1.serveBlocks(2, 3)
+	go peer1.serveBlockHashes(3, 2, 1, 0)
+	peer1.serveBlocks(0, 1, 2)
+
+	blockPool.Wait(waitTimeout)
+	blockPool.Stop()
+	blockPoolTester.refBlockChain[3] = []int{}
+	blockPoolTester.checkBlockChain(blockPoolTester.refBlockChain)
+	if len(peer1.peerErrors) == 1 {
+		if peer1.peerErrors[0] != ErrIncorrectTD {
+			t.Errorf("wrong error, got %v, expected %v", peer1.peerErrors[0], ErrIncorrectTD)
+		}
+	} else {
+		t.Errorf("expected %v error, got %v", ErrIncorrectTD, peer1.peerErrors)
+	}
+}
+
 func TestPeerSuspension(t *testing.T) {
 	test.LogInit()
 	_, blockPool, blockPoolTester := newTestBlockPool(t)
diff --git a/blockpool/peers.go b/blockpool/peers.go
index b463137e3..5cc483a3b 100644
--- a/blockpool/peers.go
+++ b/blockpool/peers.go
@@ -452,8 +452,12 @@ func (self *peer) getBlockHashes() {
 			self.addError(ErrInvalidBlock, "%v", err)
 			self.bp.status.badPeers[self.id]++
 		} else {
+			if self.currentBlock.Td != nil {
+				if self.td.Cmp(self.currentBlock.Td) != 0 {
+					self.addError(ErrIncorrectTD, "on block %x", self.currentBlockHash)
+				}
+			}
 			headKey := self.parentHash.Str()
-			height := self.bp.status.chain[headKey] + 1
 			self.bp.status.chain[self.currentBlockHash.Str()] = height
 			if height > self.bp.status.values.LongestChain {
 				self.bp.status.values.LongestChain = height
@@ -471,6 +475,7 @@ func (self *peer) getBlockHashes() {
 					block:   self.currentBlock,
 					hashBy:  self.id,
 					blockBy: self.id,
+					td:      self.td,
 				}
 				self.bp.newSection([]*node{n}).activate(self)
 			} else {
diff --git a/blockpool/peers_test.go b/blockpool/peers_test.go
index 99dd16ba1..db83de43a 100644
--- a/blockpool/peers_test.go
+++ b/blockpool/peers_test.go
@@ -15,9 +15,9 @@ import (
 func TestAddPeer(t *testing.T) {
 	test.LogInit()
 	_, blockPool, blockPoolTester := newTestBlockPool(t)
-	peer0 := blockPoolTester.newPeer("peer0", 1, 0)
-	peer1 := blockPoolTester.newPeer("peer1", 2, 1)
-	peer2 := blockPoolTester.newPeer("peer2", 3, 2)
+	peer0 := blockPoolTester.newPeer("peer0", 1, 1)
+	peer1 := blockPoolTester.newPeer("peer1", 2, 2)
+	peer2 := blockPoolTester.newPeer("peer2", 3, 3)
 	var bestpeer *peer
 
 	blockPool.Start()
@@ -38,7 +38,7 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.id != "peer2" {
 		t.Errorf("peer2 (TD=3) not set as best")
 	}
-	peer2.waitBlocksRequests(2)
+	peer2.waitBlocksRequests(3)
 
 	best = peer1.AddPeer()
 	if best {
@@ -52,7 +52,7 @@ func TestAddPeer(t *testing.T) {
 	}
 
 	peer2.td = 4
-	peer2.currentBlock = 3
+	peer2.currentBlock = 4
 	best = peer2.AddPeer()
 	if !best {
 		t.Errorf("peer2 (TD=4) not accepted as best")
@@ -63,10 +63,10 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.td.Cmp(big.NewInt(int64(4))) != 0 {
 		t.Errorf("peer2 TD not updated")
 	}
-	peer2.waitBlocksRequests(3)
+	peer2.waitBlocksRequests(4)
 
 	peer1.td = 3
-	peer1.currentBlock = 2
+	peer1.currentBlock = 3
 	best = peer1.AddPeer()
 	if best {
 		t.Errorf("peer1 (TD=3) should not be set as best")
@@ -88,7 +88,7 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.id != "peer1" {
 		t.Errorf("existing peer1 (TD=3) should be set as best peer")
 	}
-	peer1.waitBlocksRequests(2)
+	peer1.waitBlocksRequests(3)
 
 	blockPool.RemovePeer("peer1")
 	bestpeer, best = blockPool.peers.getPeer("peer1")
@@ -99,7 +99,7 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.id != "peer0" {
 		t.Errorf("existing peer0 (TD=1) should be set as best peer")
 	}
-	peer0.waitBlocksRequests(0)
+	peer0.waitBlocksRequests(1)
 
 	blockPool.RemovePeer("peer0")
 	bestpeer, best = blockPool.peers.getPeer("peer0")
diff --git a/blockpool/section.go b/blockpool/section.go
index c73aaa6df..0304c9a04 100644
--- a/blockpool/section.go
+++ b/blockpool/section.go
@@ -83,9 +83,9 @@ func (self *BlockPool) newSection(nodes []*node) *section {
 		offC:          make(chan bool),
 	}
 
-	for i, node := range nodes {
-		entry := &entry{node: node, section: sec, index: &index{i}}
-		self.set(node.hash, entry)
+	for i, n := range nodes {
+		entry := &entry{node: n, section: sec, index: &index{i}}
+		self.set(n.hash, entry)
 	}
 
 	plog.DebugDetailf("[%s] setup section process", sectionhex(sec))
@@ -104,20 +104,22 @@ func (self *section) addSectionToBlockChain(p *peer) {
 			self.bp.wg.Done()
 		}()
 
-		var node *node
+		var nodes []*node
+		var n *node
 		var keys []string
 		var blocks []*types.Block
 		for self.poolRootIndex > 0 {
-			node = self.nodes[self.poolRootIndex-1]
-			node.lock.RLock()
-			block := node.block
-			node.lock.RUnlock()
+			n = self.nodes[self.poolRootIndex-1]
+			n.lock.RLock()
+			block := n.block
+			n.lock.RUnlock()
 			if block == nil {
 				break
 			}
 			self.poolRootIndex--
 			keys = append(keys, node.hash.Str())
 			blocks = append(blocks, block)
+			nodes = append(nodes, n)
 		}
 
 		if len(blocks) == 0 {
@@ -134,13 +136,20 @@ func (self *section) addSectionToBlockChain(p *peer) {
 		err := self.bp.insertChain(blocks)
 		if err != nil {
 			self.invalid = true
-			self.bp.peers.peerError(node.blockBy, ErrInvalidBlock, "%v", err)
-			plog.Warnf("invalid block %x", node.hash)
-			plog.Warnf("penalise peers %v (hash), %v (block)", node.hashBy, node.blockBy)
+			self.bp.peers.peerError(n.blockBy, ErrInvalidBlock, "%v", err)
+			plog.Warnf("invalid block %x", n.hash)
+			plog.Warnf("penalise peers %v (hash), %v (block)", n.hashBy, n.blockBy)
 
 			// or invalid block and the entire chain needs to be removed
 			self.removeChain()
 		} else {
+			// check tds
+			self.bp.wg.Add(1)
+			go func() {
+				plog.DebugDetailf("checking td")
+				self.bp.checkTD(nodes...)
+				self.bp.wg.Done()
+			}()
 			// if all blocks inserted in this section
 			// then need to try to insert blocks in child section
 			if self.poolRootIndex == 0 {
@@ -178,7 +187,7 @@ func (self *section) addSectionToBlockChain(p *peer) {
 		self.bp.status.values.BlocksInChain += len(blocks)
 		self.bp.status.values.BlocksInPool -= len(blocks)
 		if err != nil {
-			self.bp.status.badPeers[node.blockBy]++
+			self.bp.status.badPeers[n.blockBy]++
 		}
 		self.bp.status.lock.Unlock()