Process `getheaders` messages from whitelisted peers even if we are in
initial block download. Whitelisted peers can always use a node as a
block source.
Also log a debug message when the request is ignored, for
troubleshooting.
Fixes#6971.
d1c3762 Revert "Revert "Enable policy enforcing GetMedianTimePast as the end point of lock-time constraints"" (Gregory Maxwell)
e4e5334 Restore MedianTimePast for locktime. (Gregory Maxwell)
Previously, the undo weren't being flushed during a reindex because
fKnown was set to true in FindBlockPos. That is the correct behaviour
for block files as they aren't being touched, but undo files are
touched.
This changes the behaviour to always flush when switching to a new file
(even for block files, though that isn't really necessary).
Revert "Revert "Add rules--presently disabled--for using GetMedianTimePast as endpoint for lock-time calculations""
This reverts commit 40cd32e835.
After careful analysis it was determined that the change was, in fact, safe and several people were suffering
momentary confusion about locktime semantics.
When processing a new transaction, in addition to spending the Coins of its txin's it creates a new Coins for its outputs. The existing ModifyCoins function will first make sure this Coins does not already exist. It can not exist due to BIP 30, but because of that the lookup can't be cached and always has to go to the database. Since we are creating the coins to match the new tx anyway, there is no point in checking if they exist first anyway. However this should not be used for coinbase tx's in order to preserve the historical behavior of overwriting the two existing duplicate tx pairs.
This reverts commit 9d55050773.
As noted by Luke-Jr, under some conditions this will accept transactions which are invalid by the network
rules. This happens when the current block time is head of the median time past and a transaction's
locktime is in the middle.
This could be addressed by changing the rule to MAX(this_block_time, MTP+offset) but this solution and
the particular offset used deserve some consideration.
* -maxuploadtarget can be set in MiB
* if <limit> - ( time-left-in-24h-cycle / 600 * MAX_BLOCK_SIZE ) has reach, stop serve blocks older than one week and filtered blocks
* no action if limit has reached, no guarantee that the target will not be surpassed
* add outbound limit informations to rpc getnettotals
The lock-time code currently uses CBlock::nTime as the cutoff point for time based locked transactions. This has the unfortunate outcome of creating a perverse incentive for miners to lie about the time of a block in order to collect more fees by including transactions that by wall clock determination have not yet matured. By using CBlockIndex::GetMedianTimePast from the prior block instead, the self-interested miner no longer gains from generating blocks with fraudulent timestamps. Users can compensate for this change by simply adding an hour (3600 seconds) to their time-based lock times.
If enforced, this would be a soft-fork change. This commit only adds the functionality on an unexecuted code path, without changing the behaviour of Bitcoin Core.
Add a comment that explains why the initial "getheader" requests are
made starting from the block preceding the currently best one.
Thanks to sdaftuar for the explanation!
There is no exact science to setting this parameter, but 5000
(just over 1 US cent at the time of writing) is higher than the
cost to relay a transaction around the network (the new benchmark
due to mempool limiting).
After each transaction which is added to mempool, we first call
Expire() to remove old transactions, then throwing away the
lowest-feerate transactions.
After throwing away transactions by feerate, we set the minimum
relay fee to the maximum fee transaction-and-dependant-set we
removed, plus the default minimum relay fee.
After the next block is received, the minimum relay fee is allowed
to decrease exponentially. Its halflife defaults to 12 hours, but
is decreased to 6 hours if the mempool is smaller than half its
maximum size, and 3 hours if the mempool is smaller than a quarter
its maximum size.
The minimum -maxmempool size is 40*-limitdescendantsize, as it is
easy for an attacker to play games with the cheapest
-limitdescendantsize transactions. -maxmempool defaults to 300MB.
This disables high-priority transaction relay when the min relay
fee adjustment is >0 (ie when the mempool is full). When the relay
fee adjustment drops below the default minimum relay fee / 2 it is
set to 0 (re-enabling priority-based free relay).
To bridge the time until a dynamic method for determining this fee is
merged.
This is especially aimed at the stable releases (0.10, 0.11) because
full mempool limiting, as will be in 0.12, is too invasive and risky to
backport.
Assume that when a wallet transaction has a valid block hash and transaction position
in it, the transaction is actually there. We're already trusting wallet data in a
much more fundamental way anyway.
To prevent backward compatibility issues, a new record is used for storing the
block locator in the wallet. Old wallets will see a wallet file synchronized up
to the genesis block, and rescan automatically.
Associate with each CTxMemPoolEntry all the size/fees of descendant
mempool transactions. Sort mempool by max(feerate of entry, feerate
of descendants). Update statistics on-the-fly as transactions enter
or leave the mempool.
Also add ancestor and descendant limiting, so that transactions can
be rejected if the number or size of unconfirmed ancestors exceeds
a target, or if adding a transaction would cause some other mempool
entry to have too many (or too large) a set of unconfirmed in-
mempool descendants.
GetTransaction needs to lock cs_main until ReadBlockFromDisk completes, the data inside CBlockIndex's can change since pruning. This lock was held by all calls to GetTransaction except rest_tx.
- removes mapBlockIndex find operation
- theoretically allows removing the cs_main lock during zqm notification while introducing a new file position lock
We log the cleanSubVer as part of connect. It is not uniquely more informative
than any of the other data we have about a peer, often less. It's also often
long now as well. There is no need to output it as part of mempoolrej,
AcceptToMemoryPool, or pong entries. Leaving it out makes our log entries
more uniform and consistent.
Lets nodes advertise that they offer bloom filter support explicitly.
The protocol version bump allows SPV nodes to assume that NODE_BLOOM is
set if NODE_NETWORK is set for pre-70011 nodes.
Also adds an option to turn bloom filter support off for nodes which
advertise a version number >= 70011. Nodes attempting to use bloom
filters on such protocol versions are banned, and a later upgade
should drop nodes of an older version which attempt to use bloom
filters.
Much code stolen from Peter Todd.
Implements BIP 111
The main effect is to exit processing for recently-rejected hashes,
in case they are pushed to us without prior advertisement. This
behavior was seen in the wild.
An additional effect is to do early checks for mempool or mapOrphan
existence. No logging or nDoS tracking is needed for failures of
these checks.
7f1f8f5 Move mempool rejections to new debug category (Wladimir J. van der Laan)
66daed5 Add information to errors in ConnectBlock, CheckBlock (Wladimir J. van der Laan)
6cab808 Remove most logging from transaction validation (Wladimir J. van der Laan)
9003c7c Add function to convert CValidationState to a human-readable message (Wladimir J. van der Laan)
dc58258 Introduce REJECT_INTERNAL codes for local AcceptToMempool errors (Wladimir J. van der Laan)
fbf44e6 Add debug message to CValidationState for optional extra information (Wladimir J. van der Laan)
Move mempool rejections to debug category `mempoolrej`, to make it possible
to show them without enabling the entire category `mempool` which is
high volume.
Add detailed state information to the errors, as it is no longer being
logged downstream.
Also add the state information to mempool rejection debug message in
ProcessMessages.
Remove unnecessary direct logging in CheckTransaction,
AcceptToMemoryPool, CheckTxInputs, CScriptCheck::operator()
All status information should be returned in the CValidationState.
Relevant debug information is also added to the CValidationState using
the recently introduced debug message.
Do keep the "BUG! PLEASE REPORT THIS! ConnectInputs failed against MANDATORY but not STANDARD flags"
error as it is meant to appear as bug in the log.
Add status codes specific to AcceptToMempool procession of transactions.
These can never happen due to block validation, and must never be sent
over the P2P network. Add assertions where appropriate.
5922b67 Add assertion and cast before sending reject code (Wladimir J. van der Laan)
a651403 Add absurdly high fee message to validation state (for RPC propagation) (Shaul Kfir)
This gets rid of a warning. Add an assertion to make sure that the
reject code is in the correct range for the network protocol
(if it is outside the range it must be a bug)
7b79cbd limit total length of user agent comments (Pavol Rusnak)
557f8ea implement uacomment config parameter which can add comments to user agent as per BIP-0014 (Pavol Rusnak)
a8d0407 Move recentRejects initialization to top of InitBlockIndex (Wladimir J. van der Laan)
0847d9c Keep track of recently rejected transactions (Peter Todd)
d741371 Only use randomly created nonces in CRollingBloomFilter. (Pieter Wuille)
d2d7ee0 Make CRollingBloomFilter set nTweak for you (Peter Todd)
a3d65fe Reuse vector hashing code for uint256 (Pieter Wuille)
bbe4108 Add uint256 support to CRollingBloomFilter (Peter Todd)
This avoids that premature return in the condition that a new chain is initialized
results in NULL pointer errors due to recentReject not being constructed.
Also add assertions where it is used.
59b49cd Eliminate signed/unsigned comparison warning (Suhas Daftuar)
04b5d23 Replace sleep with syncing using pings (Suhas Daftuar)
6b1066f Ignore whitelisting during IBD for unrequested blocks. (Suhas Daftuar)
bfc30b3 Ignore unrequested blocks too far ahead of tip (Suhas Daftuar)
Nodes can have divergent policies on which transactions they will accept
and relay. This can cause you to repeatedly request and reject the same
tx after its inved to you from various peers which have accepted it.
Here we add rolling bloom filter to keep track of such rejections,
clearing the filter every time the chain tip changes.
Credit goes to Alex Morcos, who created the patch that this code is
based on.
Original code by Peter Todd. Refactored to not construct the
filter at startup time by Pieter Wuille.
While CBloomFilter is usually used with an explicitly set nTweak,
CRollingBloomFilter is only used internally. Requiring every caller to
set nTweak is error-prone and redundant; better to have the class handle
that for you with a high-quality randomness source.
Additionally when clearing the filter it makes sense to change nTweak as
well to recover from a bad setting, e.g. due to insufficient randomness
at initialization, so the clear() method is replaced by a reset() method
that sets a new, random, nTweak value.
a794284 locking: add a quick example of GUARDED_BY (Cory Fields)
2b890dd locking: fix a few small issues uncovered by -Wthread-safety (Cory Fields)
cd27bba locking: teach Clang's -Wthread-safety to cope with our scoped lock macros (Cory Fields)
Handle the case where no chain tip is available, in InvalidChainFound(). This fixes a null pointer deference when running unit tests, if the genesis block or block validation code is broken.
4f40716 test: Move reindex test to standard tests (Wladimir J. van der Laan)
36c97b4 Bugfix: Don't check the genesis block header before accepting it (Jorge Timón)
When responding to a getblocks message, only return inv's as
long as we HAVE_DATA for blocks in the chain, and only for blocks
that we aren't likely to delete in the near future.
Make it possible to opt-out of the centralized alert system by providing
an option `-noalerts` or `-alerts=0`. The default remains unchanged.
This is a gentler form of #6260, in which I went a bit overboard by
removing the alert system completely.
I intend to add this to the GUI options in another pull after this.
The partition checking code was using chainActive timestamps
to detect partitioning; with headers-first syncing, it should use
(and with this pull request, does use) pIndexBestHeader timestamps.
Fixes issue #6251
This prevents an edge case where a block downloaded and pruned
in-between successive calls to FindNextBlocksToDownload could
cause the block to be unnecessarily re-requested.
In some corner cases, it may be possible for recent blocks to end up in
the same block file as much older blocks. Previously, the pruning code
would stop looking for files to remove upon first encountering a file
containing a block that cannot be pruned, now it will keep looking for
candidate files until the target is met and all other criteria are
satisfied.
This can result in a noncontiguous set of block files (by number) on
disk, which is fine except for during some reindex corner cases, so
make reindex preparation smarter such that we keep the data we can
actually use and throw away the rest. This allows pruning to work
correctly while downloading any blocks needed during the reindex.
Previously due to an off-by-one error the wallet ignored
nLockTime-by-height transactions that would be valid in the next block
even though they are accepted into the mempool. The transactions
wouldn't show up until confirmed, nor would they be included in the
unconfirmed balance. Similar to the mempool behavior fix in 665bdd3b,
the wallet code was calling IsFinalTx() directly without taking into
account the fact that doing so tells you if the transaction could have
been mined in the *current* block, rather than the next block.
To fix this we strip IsFinalTx() of non-consensus-critical
functionality, removing the default arguments, and add CheckFinalTx() to
check if a transaction will be final in the next block.
Previously this was cleared only after UnlinkPrunedFiles, but it should really be cleared after FindFilesToPrune, regardless of whether there are any files to be pruned.
86a5f4b Relocate calls to CheckDiskSpace (Alex Morcos)
67708ac Write block index more frequently than cache flushes (Pieter Wuille)
b3ed423 Cache tweak and logging improvements (Pieter Wuille)
fc684ad Use accurate memory for flushing decisions (Pieter Wuille)
046392d Keep track of memory usage in CCoinsViewCache (Pieter Wuille)
540629c Add memusage.h (Pieter Wuille)
Create a monitoring task that counts how many blocks have been found in the last four hours.
If very few or too many have been found, an alert is triggered.
"Very few" and "too many" are set based on a false positive rate of once every fifty years of constant running with constant hashing power, which works out to getting 5 or fewer or 48 or more blocks in four hours (instead of the average of 24).
Only one alert per day is triggered, so if you get disconnected from the network (or are being Sybil'ed) -alertnotify will be triggered after 3.5 hours but you won't get another -alertnotify for 24 hours.
Tested with a new unit test and by running on the main network with -debug=partitioncheck
Run test/test_bitcoin --log_level=message to see the alert messages:
WARNING: check your network connection, 3 blocks received in the last 4 hours (24 expected)
WARNING: abnormally high number of blocks generated, 60 blocks received in the last 4 hours (24 expected)
The -debug=partitioncheck debug.log messages look like:
ThreadPartitionCheck : Found 22 blocks in the last 4 hours
ThreadPartitionCheck : likelihood: 0.0777702
Instead of only checking height to decide whether to disable script checks,
actually check whether a block is an ancestor of a checkpoint, up to which
headers have been validated. This means that we don't have to prevent
accepting a side branch anymore - it will be safe, just less fast to
do.
We still need to prevent being fed a multitude of low-difficulty headers
filling up our memory. The mechanism for that is unchanged for now: once
a checkpoint is reached with headers, no headers chain branching off before
that point are allowed anymore.
This class groups transactions that have been confirmed in blocks into buckets, based on either their fee or their priority. Then for each bucket, the class calculates what percentage of the transactions were confirmed within various numbers of blocks. It does this by keeping an exponentially decaying moving history for each bucket and confirm block count of the percentage of transactions in that bucket that were confirmed within that number of blocks.
-Eliminate txs which didn't have all inputs available at entry from fee/pri calcs
-Add dynamic breakpoints and tracking of confirmation delays in mempool transactions
-Remove old CMinerPolicyEstimator and CBlockAverage code
-New smartfees.py
-Pass a flag to the estimation code, using IsInitialBlockDownload as a proxy for when we are still catching up and we shouldn't be counting how many blocks it takes for transactions to be included.
-Add a policyestimator unit test
We don't want to erase orphans that still have missing inputs, they should still be tracked as orphans. Also, the transaction thats being accepted can't be an orphan otherwise it would have previously been accepted, so doesn't need to be added to the erase queue.
a8cdaf5 checkpoints: move the checkpoints enable boolean into main (Cory Fields)
11982d3 checkpoints: Decouple checkpoints from Params (Cory Fields)
6996823 checkpoints: make checkpoints a member of CChainParams (Cory Fields)
9f13a10 checkpoints: store mapCheckpoints in CCheckpointData rather than a pointer (Cory Fields)
Use a probabilistic bloom filter to keep track of which addresses
we think we have given our peers, instead of a list.
This uses much less memory, at the cost of sometimes failing to
relay an address to a peer-- worst case if the bloom filter happens
to be as full as it gets, 1-in-1,000.
Measured memory usage of a full mruset setAddrKnown: 650Kbytes
Constant memory usage of CRollingBloomFilter addrKnown: 37Kbytes.
This will also help heap fragmentation, because the 37K of storage
is allocated when a CNode is created (when a connection to a peer
is established) and then there is no per-item-remembered memory
allocation.
I plan on testing by restarting a full node with an empty peers.dat,
running a while with -debug=addrman and -debug=net, and making sure
that the 'addr' message traffic out is reasonable.
(suggestions for better tests welcome)
This adds a -prune=N option to bitcoind, which if set to N>0 will enable block
file pruning. When pruning is enabled, block and undo files will be deleted to
try to keep total space used by those files to below the prune target (N, in
MB) specified by the user, subject to some constraints:
- The last 288 blocks on the main chain are always kept (MIN_BLOCKS_TO_KEEP),
- N must be at least 550MB (chosen as a value for the target that could
reasonably be met, with some assumptions about block sizes, orphan rates,
etc; see comment in main.h),
- No blocks are pruned until chainActive is at least 100,000 blocks long (on
mainnet; defined separately for mainnet, testnet, and regtest in chainparams
as nPruneAfterHeight).
This unsets NODE_NETWORK if pruning is enabled.
Also included is an RPC test for pruning (pruning.py).
Thanks to @rdponticelli for earlier work on this feature; this is based in
part off that work.
Compare the block download timeout to what the timeout would be if calculated
based on current time and current value of nQueuedValidatedHeaders, but
ignoring other in-flight blocks from the same peer. If the calculation based on
present conditions is shorter, then set that to be the time after which we
disconnect the peer for not delivering this block.
