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Ignore unrequested blocks too far ahead of tip

This commit is contained in:
Suhas Daftuar 2015-06-02 15:17:36 -04:00
parent 9d60602444
commit bfc30b3437
2 changed files with 63 additions and 11 deletions
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65
qa/rpc-tests/p2p-acceptblock.py
View File

@ -40,6 +40,11 @@ The test:
it's missing an intermediate block.
Node1 should reorg to this longer chain.
4b.Send 288 more blocks on the longer chain.
Node0 should process all but the last block (too far ahead in height).
Send all headers to Node1, and then send the last block in that chain.
Node1 should accept the block because it's coming from a whitelisted peer.
5. Send a duplicate of the block in #3 to Node0.
Node0 should not process the block because it is unrequested, and stay on
the shorter chain.
@ -126,13 +131,15 @@ class AcceptBlockTest(BitcoinTestFramework):
# 2. Send one block that builds on each tip.
# This should be accepted.
blocks_h2 = [] # the height 2 blocks on each node's chain
block_time = time.time() + 1
for i in xrange(2):
blocks_h2.append(create_block(tips[i], create_coinbase(), time.time()+1))
blocks_h2.append(create_block(tips[i], create_coinbase(), block_time))
blocks_h2[i].solve()
block_time += 1
test_node.send_message(msg_block(blocks_h2[0]))
white_node.send_message(msg_block(blocks_h2[1]))
time.sleep(1)
time.sleep(0.5)
assert_equal(self.nodes[0].getblockcount(), 2)
assert_equal(self.nodes[1].getblockcount(), 2)
print "First height 2 block accepted by both nodes"
@ -145,7 +152,7 @@ class AcceptBlockTest(BitcoinTestFramework):
test_node.send_message(msg_block(blocks_h2f[0]))
white_node.send_message(msg_block(blocks_h2f[1]))
time.sleep(1) # Give time to process the block
time.sleep(0.5) # Give time to process the block
for x in self.nodes[0].getchaintips():
if x['hash'] == blocks_h2f[0].hash:
assert_equal(x['status'], "headers-only")
@ -164,7 +171,7 @@ class AcceptBlockTest(BitcoinTestFramework):
test_node.send_message(msg_block(blocks_h3[0]))
white_node.send_message(msg_block(blocks_h3[1]))
time.sleep(1)
time.sleep(0.5)
# Since the earlier block was not processed by node0, the new block
# can't be fully validated.
for x in self.nodes[0].getchaintips():
@ -182,6 +189,45 @@ class AcceptBlockTest(BitcoinTestFramework):
assert_equal(self.nodes[1].getblockcount(), 3)
print "Successfully reorged to length 3 chain from whitelisted peer"
# 4b. Now mine 288 more blocks and deliver; all should be processed but
# the last (height-too-high) on node0. Node1 should process the tip if
# we give it the headers chain leading to the tip.
tips = blocks_h3
headers_message = msg_headers()
all_blocks = [] # node0's blocks
for j in xrange(2):
for i in xrange(288):
next_block = create_block(tips[j].sha256, create_coinbase(), tips[j].nTime+1)
next_block.solve()
if j==0:
test_node.send_message(msg_block(next_block))
all_blocks.append(next_block)
else:
headers_message.headers.append(CBlockHeader(next_block))
tips[j] = next_block
time.sleep(2)
for x in all_blocks:
try:
self.nodes[0].getblock(x.hash)
if x == all_blocks[287]:
raise AssertionError("Unrequested block too far-ahead should have been ignored")
except:
if x == all_blocks[287]:
print "Unrequested block too far-ahead not processed"
else:
raise AssertionError("Unrequested block with more work should have been accepted")
headers_message.headers.pop() # Ensure the last block is unrequested
white_node.send_message(headers_message) # Send headers leading to tip
white_node.send_message(msg_block(tips[1])) # Now deliver the tip
try:
time.sleep(0.5)
self.nodes[1].getblock(tips[1].hash)
print "Unrequested block far ahead of tip accepted from whitelisted peer"
except:
raise AssertionError("Unrequested block from whitelisted peer not accepted")
# 5. Test handling of unrequested block on the node that didn't process
# Should still not be processed (even though it has a child that has more
# work).
@ -204,21 +250,20 @@ class AcceptBlockTest(BitcoinTestFramework):
test_node.last_getdata = None
test_node.send_message(msg_inv([CInv(2, blocks_h3[0].sha256)]))
time.sleep(1)
time.sleep(0.5)
with mininode_lock:
getdata = test_node.last_getdata
# Check that the getdata is for the right block
assert_equal(len(getdata.inv), 1)
# Check that the getdata includes the right block
assert_equal(getdata.inv[0].hash, blocks_h2f[0].sha256)
print "Inv at tip triggered getdata for unprocessed block"
# 7. Send the missing block for the third time (now it is requested)
test_node.send_message(msg_block(blocks_h2f[0]))
time.sleep(1)
assert_equal(self.nodes[0].getblockcount(), 3)
print "Successfully reorged to length 3 chain from non-whitelisted peer"
time.sleep(2)
assert_equal(self.nodes[0].getblockcount(), 290)
print "Successfully reorged to longer chain from non-whitelisted peer"
[ c.disconnect_node() for c in connections ]

9
src/main.cpp
View File

@ -2841,9 +2841,15 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex,
// Try to process all requested blocks that we don't have, but only
// process an unrequested block if it's new and has enough work to
// advance our tip.
// advance our tip, and isn't too many blocks ahead.
bool fAlreadyHave = pindex->nStatus & BLOCK_HAVE_DATA;
bool fHasMoreWork = (chainActive.Tip() ? pindex->nChainWork > chainActive.Tip()->nChainWork : true);
// Blocks that are too out-of-order needlessly limit the effectiveness of
// pruning, because pruning will not delete block files that contain any
// blocks which are too close in height to the tip. Apply this test
// regardless of whether pruning is enabled; it should generally be safe to
// not process unrequested blocks.
bool fTooFarAhead = (pindex->nHeight - chainActive.Height()) > MIN_BLOCKS_TO_KEEP;
// TODO: deal better with return value and error conditions for duplicate
// and unrequested blocks.
@ -2851,6 +2857,7 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex,
if (!fRequested) { // If we didn't ask for it:
if (pindex->nTx != 0) return true; // This is a previously-processed block that was pruned
if (!fHasMoreWork) return true; // Don't process less-work chains
if (fTooFarAhead) return true; // Block height is too high
}
if ((!CheckBlock(block, state)) || !ContextualCheckBlock(block, state, pindex->pprev)) {