Changes AddToMempool() helper to only apply changes if the mempool limits are
respected.
Fix package_rbf fuzz target to handle mempool policy violations
Calculating mempool ancestors for a new transaction should not be done until
after cluster size limits have been enforced, to limit CPU DoS potential.
Achieve this by reworking TRUC and RBF validation logic:
- TRUC policy enforcement is now done using only mempool parents of
new transactions, not all mempool ancestors (note that it's fine to calculate
ancestors of in-mempool transactions, if the number of such calls is
reasonably bounded).
- RBF replacement checks are performed earlier (which allows for checking
cluster size limits earlier, because cluster size checks cannot happen until
after all conflicts are staged for removal).
- Verifying that a new transaction doesn't conflict with an ancestor now
happens later, in AcceptSingleTransaction() rather than in PreChecks(). This
means that the test is not performed at all in AcceptMultipleTransactions(),
but in package acceptance we already disallow RBF in situations where a
package transaction has in-mempool parents.
Also to ensure that all RBF validation logic is applied in both the single
transaction and multiple transaction cases, remove the optimization that skips
the PackageMempoolChecks() in the case of a single transaction being validated
in AcceptMultipleTransactions().
Now that ancestor calculation never fails (due to ancestor/descendant limits
being eliminated), we can eliminate the error handling from
CalculateMemPoolAncestors.
With the descendant size limits removed, replace the concept of "max number of
descendants of any ancestor of a given tx" with the cluster count of the cluster
that the transaction belongs to.
The mempool clusters and linearization permit sorting the mempool topologically
without making use of ancestor counts (as long as the graph is not oversized).
Co-authored-by: Pieter Wuille <pieter@wuille.net>
Previously, transaction batches were first sorted by ancestor count and then
feerate, to ensure transactions are announced in a topologically valid order,
while prioritizing higher feerate transactions. Ancestor count is a crude
topological sort criteria, so replace this with linearization order so that the
highest feerate transactions (as would be observed by the mining algorithm) are
relayed before lower feerate ones, in a topologically valid way.
This also fixes a test that only worked due to the ancestor-count-based sort
order.
With a total ordering on mempool transactions, we are now able to calculate a
transaction's mining score at all times. Use this to improve the RBF logic:
- we no longer enforce a "no new unconfirmed parents" rule
- we now require that the mempool's feerate diagram must improve in order
to accept a replacement
- the topology restrictions for conflicts in the package rbf setting have been
eliminated
Revert the temporary change to mempool_ephemeral_dust.py that were previously
made due to RBF validation checks being reordered.
Co-authored-by: Gregory Sanders <gsanders87@gmail.com>, glozow <gloriajzhao@gmail.com>
The addition of a cluster size limit makes the CPFP carveout rule useless,
because carveout cannot be used to bypass the cluster size limit. Remove this
policy rule and update tests to no longer rely on the behavior.
After cluster mempool, the mini_miner will no longer match the miner's block
construction. Eventually mini_miner should be reworked to directly use
linearizations done in the mempool.
Rather than evicting the transactions with the lowest descendant feerate,
instead evict transactions that have the lowest chunk feerate.
Once mining is implemented based on choosing transactions with highest chunk
feerate (see next commit), mining and eviction will be opposites, so that we
will evict the transactions that would be mined last.
Include an adjustment to mempool_tests.cpp due to the additional memory used by
txgraph.
Includes a temporary change to the mempool_ephemeral_dust.py functional test,
due to validation checks being reordered. This change will revert once the RBF
rules are changed in a later commit.
Rather than individually calling addUnchecked for each transaction added in a
changeset (after removing all the to-be-removed transactions), instead we can
take advantage of boost::multi_index's splicing features to extract and insert
entries directly from the staging multi_index into mapTx.
This has the immediate advantage of saving allocation overhead for mempool
entries which have already been allocated once. This also means that the memory
locations of mempool entries will not change when transactions go from staging
to the main mempool.
Additionally, eliminate addUnchecked and require all new transactions to enter
the mempool via a CTxMemPoolChangeSet.
Add new PeerManagerImpl::TryDownloadingHistoricalBlocks method and use it to
request background chain blocks in addition to blocks normally requested by
FindNextBlocksToDownload.
Co-authored-by: Ryan Ofsky <ryan@ofsky.org>
Co-authored-by: James O'Beirne <james.obeirne@gmail.com>
This is to (a) avoid repeated lookups into the block index for an entry that
should never change and (b) emphasize that the snapshot base should always
exist when set and not change during the runtime of the program.
Thanks to Russ Yanofsky for suggesting this approach.
Also rewrite CheckBlockIndex() to perform tests on all chainstates.
This increases sanity-check coverage, as any place in our code where we were
invoke CheckBlockIndex() on a single chainstate will now invoke the sanity
checks on all chainstates.
This change also tightens up the checks on setBlockIndexCandidates and
mapBlocksUnlinked, to more precisely match what we aim for even in the presence
of assumed-valid blocks.
When using assumeutxo and multiple chainstates are active, the background
chainstate should consider all HAVE_DATA blocks that are ancestors of the
snapshotted block and that have more work than the tip as potential candidates.
When using assumeutxo, we only need the background chainstate to consider
blocks that are on the chain leading to the snapshotted block.
Note that this introduces the new invariant that we can only have an assumeutxo
snapshot where the snapshotted blockhash is in our block index. Unknown block
hashes that are somehow passed in will cause assertion failures when processing
new blocks.
Includes test fixes and improvements by Andrew Chow and Fabian Jahr.
Separate the notion of which blocks are stored on disk, and what data is in our
block index, from what tip a chainstate might be able to get to. We can use
chainstate-agnostic data to determine when to store a block on disk (primarily,
an anti-DoS set of criteria) and let the chainstates figure out for themselves
when a block is of interest for being a candidate tip.
Note: some of the invariants in CheckBlockIndex are modified, but more work is
needed (ie to move CheckBlockIndex to ChainstateManager, as most of what
CheckBlockIndex is doing is checking the consistency of the block index, which
is outside of Chainstate).
When simulating a snapshot, remove the HAVE_DATA status for blocks below the
snapshot height, to simulate never having downloaded them at all. This makes
tests more realistic (and more closely match what will happen when using
assumeutxo).
Block arrival information (and the preciousblock RPC, a related concept) are
both chainstate-agnostic, so these are moved to ChainstateManager. This should
just be a refactor, without any observable behavior changes.
When writing a new block to disk, if we have filled up the current block file,
then we flush and truncate that block file (to free allocated but unused
space) before advancing to the next one. When this happens, we have to
determine whether to also flush and truncate the corresponding undo file.
Undo data is only written when blocks are connected, not when blocks are
received. Thus it's possible that the corresponding undo file already has all
the data it will ever have, and we should flush/truncate it as we advance
files; or it's possible that there is more data we expect to write, and should
therefore defer flush/truncation until undo data is later written.
Prior to this commit, we made the determination of whether the undo file was
full of all requisite data by comparing against the chain tip. This patch
replaces that dependence on validation data structures by instead just tracking
the highest height of any block written in the undo file as we go.
This commit moves P2SH activation back to the genesis block, with
a hardcoded exception for the one historical block in the chain that
violated this rule.
A peer could try to waste our resources by sending us unrequested blocks with
low work, eg to fill up our disk. Since
e2652002b6 we no longer request blocks until we
know we're on a chain with more than nMinimumChainWork (our anti-DoS
threshold), but we would still process unrequested blocks that had more work
than our tip. This commit fixes that behavior.
Replace witness-stripped wallet transactions with full transactions;
this can happen when upgrading from a pre-segwit wallet to a segwit-
aware wallet.
This test was passing because we never fetch blocks if we only receive
an inv and not the header (after 037159cebf),
and this test wasn't delivering the header.
More accurate than simply adding one byte per input, and properly handles the
case where the original transaction happened to have very small signatures
Suhas Daftuar