c0d91fc69c Add release note for #33050 and #33183 error string changes (Antoine Poinsot)
b3f781a0ef contrib: adapt max reject string size in tracing demo (Antoine Poinsot)
9a04635432 scripted-diff: validation: rename mandatory errors into block errors (Antoine Poinsot)
Pull request description:
This is a followup to #33050 now that it's merged. Using "block"/"mempool" as the error reason is clearer to a user than "mandatory"/"non-mandatory". The "non-mandatory" errors got renamed to "mempool" in #33050 (see https://github.com/bitcoin/bitcoin/pull/33050#discussion_r2230103371). This takes care of the second part of the renaming.
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ajtowns:
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Crypt-iQ:
utACK c0d91fc69c
janb84:
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Tree-SHA512: b463e633c57dd1eae7c49d23239a59066a672f355142ec194982eddc927a7646bc5cde583dc8d6f45075bf5cbb96dbe73f7e339e728929b0eff356b674d1b68c
ba84a25dee [doc] update mempool-replacements.md for incremental relay feerate change (glozow)
18720bc5d5 [doc] release note for min feerate changes (glozow)
6da5de58ca [policy] lower default minrelaytxfee and incrementalrelayfee to 100sat/kvB (glozow)
2e515d2897 [prep/test] make wallet_fundrawtransaction's minrelaytxfee assumption explicit (glozow)
457cfb61b5 [prep/util] help MockMempoolMinFee handle more precise feerates (glozow)
3eab8b7240 [prep/test] replace magic number 1000 with respective feerate vars (glozow)
5f2df0ef78 [miner] lower default -blockmintxfee to 1sat/kvB (glozow)
d6213d6aa1 [doc] assert that default min relay feerate and incremental are the same (glozow)
1fbee5d7b6 [test] explicitly check default -minrelaytxfee and -incrementalrelayfee (glozow)
72dc18467d [test] RBF rule 4 for various incrementalrelayfee settings (glozow)
85f498893f [test] check bypass of minrelay for various minrelaytxfee settings (glozow)
e5f896bb1f [test] check miner doesn't select 0fee transactions (glozow)
Pull request description:
ML post for discussion about the general concept, how this impacts the wider ecosystem, philosophy about minimum feerates, etc: https://delvingbitcoin.org/t/changing-the-minimum-relay-feerate/1886
This PR is inspired by #13922 and #32959 to lower the minimum relay feerate in response to bitcoin's exchange rate changes in the last ~10 years. It lowers the default `-minrelaytxfee` and `-incrementalrelayfee`, and knocks `-blockmintxfee` down to the minimum nonzero setting. Also adds some tests for the settings and pulls in #32750.
The minimum relay feerate is a DoS protection rule, representing a price on the network bandwidth used to relay transactions that have no PoW. While relay nodes don't all collect fees, the assumption is that if nodes on the network use their resources to relay this transaction, it will reach a miner and the attacker's money will be spent once it is mined. The incremental relay feerate is similar: it's used to price the relay of replacement transactions (the additional fees need to cover the new transactions at this feerate) and evicted transactions (following a trim, the new mempool minimum feerate is the package feerate of what was removed + incremental).
Also note that many nodes on the network have elected to relay/mine lower feerate transactions. Miners (some say up to 85%) are choosing to mine these low feerate transactions instead of leaving block space unfilled, but these blocks have extremely poor compact block reconstruction rates with nodes that rejected or didn't hear about those transactions earlier.
- https://github.com/bitcoin/bitcoin/pull/33106#issuecomment-3155627414
- https://x.com/caesrcd/status/1947022514267230302
- https://mempool.space/block/00000000000000000001305770e0aa279dcd8ba8be18c3d5cf736a26f77e06fd
- https://mempool.space/block/00000000000000000001b491649ec030aa8e003e1f4f9d3b24bb99ba16f91e97
- https://x.com/mononautical/status/1949452586391855121
While it wouldn't make sense to loosen DoS restrictions recklessly in response to these events, I think the current price is higher than necessary, and this motivates us changing the default soon. Since the minimum relay feerate defines an amount as too small based on what it costs the attacker, it makes sense to consider BTC's conversion rate to what resources you can buy in the "real world."
Going off of [this comment](https://github.com/bitcoin/bitcoin/pull/32959#issuecomment-3095260286) and [this comment](https://github.com/bitcoin/bitcoin/pull/33106#issuecomment-3142444090)
- Let's say an attacker wants to use/exhaust the network's bandwidth, and has the choice between renting resources from a commercial provider and getting the network to "spam" itself it by sending unconfirmed transactions. We'd like the latter to be more expensive than the former.
- The bandwidth for relaying a transaction across the network is roughly its serialized size (plus relay overhead) x number of nodes. A 1000vB transaction is 1000-4000B serialized. With 100k nodes, that's 0.1-0.4GB
- If the going rate for ec2 bandwidth is 10c/GB, that's like 1-4c per kvB of transaction data
- Then a 1000vB transaction should pay at least 4c
- $0.04 USD is 40 satoshis at 100k USD/BTC
- Baking in some margin for changes in USD/BTC conversion rate, number of nodes (and thus bandwidth), and commercial service costs, I think 50-100 satoshis is on the conservative end but in the right ballpark
- At least 97% of the recent sub-1sat/vB transactions would be accepted with a new threshold of 0.1sat/vB: https://github.com/bitcoin/bitcoin/pull/33106#issuecomment-3156213089
List of feerates that are changed and why:
- min relay feerate: significant conversion rate changes, see above
- incremental relay feerate: should follow min relay feerate, see above
- block minimum feerate: shouldn’t be above min relay feerate, otherwise the node accepts transactions it will never mine. I've knocked it down to the bare minimum of 1sat/kvB. Now that we no longer have coin age priority (removed in v0.15), I think we can leave it to the `CheckFeeRate` policy rule to enforce a minimum entry price, and the block assembly code should just fill up the block with whatever it finds in mempool.
List of feerates that are not changed and why:
- dust feerate: this feerate cannot be changed as flexibly as the minrelay feerate. A much longer record of low feerate transactions being mined is needed to motivate a decrease there.
- maxfeerate (RPC, wallet): I think the conversion rate is relevant as well, but out of scope for this PR
- minimum feerate returned by fee estimator: should be done later. In the past, we've excluded new policy defaults from fee estimation until we feel confident they represent miner policy (e.g. #9519). Also, the fee estimator itself doesn't have support for sub-1sat/vB yet.
- all wallet feerates (mintxfee, fallbackfee, discardfee, consolidatefeerate, WALLET_INCREMENTAL_RELAY_FEE, etc.): should be done later. Our standard procedure is to do wallet changes at least 1 release after policy changes.
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ACK ba84a25dee
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crACK ba84a25dee
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re-ACK ba84a25dee
Tree-SHA512: b4c35e8b506b1184db466551a7e2e48bb1e535972a8dbcaa145ce3a8bfdcc70a8807dc129460f129a9d31024174d34077154a387c32f1a3e6831f6fa5e9c399e
Using "block" or "mempool" as the prefix in place of "mandatory" or "non-mandatory" is clearer
to a user. "non-mandatory" was renamed into "mempool" as part of #33050. This takes care of the
other half of this renaming as a scripted diff.
-BEGIN VERIFY SCRIPT-
sed -i 's/mandatory-script-verify/block-script-verify/g' $(git grep -l mandatory-script-verify)
-END VERIFY SCRIPT-
Back when we implemented coin age priority as a miner policy, miners
mempools might admit transactions paying very low fees, but then want to
set a higher fee for block inclusion. However, since coin age priority
was removed in v0.15, the block assembly policy is solely based on fees,
so we do not need to apply minimum feerate rules in multiple places. In
fact, the block assembly policy ignoring transactions that are added to
the mempool is likely undesirable as we waste resources accepting and
storing this transaction.
Instead, rely on mempool policy to enforce a minimum entry feerate to
the mempool (minrelaytxfee). Set the minimum block feerate to the
minimum non-zero amount (1sat/kvB) so it collects everything it finds in
mempool into the block.
The Consensus Cleanup soft fork proposal includes enforcing that coinbase transactions set their
locktime field to the block height, minus 1 (as well as their nSequence such as to not disable the
timelock). If such a fork were to be activated by Bitcoin users, miners need to be ready to produce
compliant blocks at the risk of losing substantial amounts mining would-be invalid blocks. As miners
are unfamously slow to upgrade, it's good to make this change as early as possible.
Although Bitcoin Core's GBT implementation does not provide the "coinbasetxn" field, and mining
pool software crafts the coinbase on its own, updating the Bitcoin Core mining code is a first step
toward convincing pools to update their (often closed source) code. A possible followup is also to
introduce new fields to GBT. In addition, this first step also makes it possible to test future
Consensus Cleanup changes.
The changes to the seemingly-unrelated RBF tests is because these tests assert an error message
which may vary depending on the txid of the transactions used in the test. This commit changes the
coinbase transaction structure and therefore impact the txid of transactions in all tests.
The change to the "Bad snapshot" error message in the assumeutxo functional test is because this
specific test case reads into the txid of the next transaction in the snapshot and asserts the error
message based it gets on deserializing this txid as a coin for the previous transaction. As this
commit changes this txid it impacts the deserialization error raised.
- The package feerates are ordered by the sequence in which
packages are selected for inclusion in the block template.
- The commit also tests this new behaviour.
Co-authored-by: willcl-ark <will@256k1.dev>
This makes the debug output mostly the same for -par=1 and parallel validation runs. Of course,
parallel validation is non-deterministic in what error it may encounter first if there are
multiple issues. Also, the way certain script-related and non-script-related checks are
performed differs between the two modes still, which may result in discrepancies.
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.
The following scripted-diff commit will replace ParseHex("...") with "..."_hex_u8, but this replacement will not work in cases where vectors are needed instead of arrays, and is not ideal in cases where std::byte is accepted.
For example, it is currently necessary to use _hex_v_u8 when calling CScript operator<< because that operator does not currently support std::array or std::byte.
Conversely, it is incorrect to use _hex_v instead of _hex in net_processing.cpp for the MakeAndPushMessage argument, because if the argument is a std::vector it is considered variable-length and serialized with a size prefix, but if the argument is a std::array or Span is it considered fixed length and serialized without a prefix.
By the same logic, it is also safe to change the NUMS_H constant in pubkey.cpp from a std::vector to std::array because it is never serialized.
429ec1aaaa refactor: Rename CTransaction::nVersion to version (Ava Chow)
27e70f1f5b consensus: Store transaction nVersion as uint32_t (Ava Chow)
Pull request description:
Given that the use of a transaction's nVersion is always as an unsigned int, it doesn't make sense to store it as signed and then cast it to unsigned everywhere it is used and displayed.
Since a few alternative implementations have recently been revealed to have made an error with this signedness that would have resulted in consensus failure, I think it makes sense for us to just make this always unsigned to make it clear that the version is treated as unsigned. This would also help us avoid future potential issues with signedness of this value.
I believe that this is safe and does not actually change what transactions would or would not be considered both standard and consensus valid. Within consensus, the only use of the version in consensus is in BIP68 validation which was already casting it to uint32_t. Within policy, although it is used as a signed int for the transaction version number check, I do not think that this change would change standardness. Standard transactions are limited to the range [1, 2]. Negative numbers would have fallen under the < 1 condition, but by making it unsigned, they are still non-standard under the > 2 condition.
Unsigned and signed ints are serialized and unserialized the same way so there is no change in serialization.
ACKs for top commit:
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shaavan:
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Tree-SHA512: 0bcd92a245d7d16c3665d2d4e815a4ef28207ad4a1fb46c6f0203cdafeab1b82c4e95e4bdce7805d80a4f4a46074f6542abad708e970550d38a00d759e3dcef1
In order to ensure that the change of nVersion to a uint32_t in the
previous commit has no effect, rename nVersion to version in this commit
so that reviewers can easily spot if a spot was missed or if there is a
check somewhere whose semantics have changed.
CTxDestination is really our internal representation of an address and
doesn't really have anything to do with standard script types, so move
them to their own file.
Since the kernel library no longer depends on the system file, move it
to the common library instead in accordance to the diagram in
doc/design/libraries.md.
75db62ba4c refactor: Move calculation logic out from `CheckSequenceLocksAtTip()` (Hennadii Stepanov)
3bc434f459 refactor: Add `CalculateLockPointsAtTip()` function (Hennadii Stepanov)
Pull request description:
This PR is follow up for bitcoin/bitcoin#22677 and bitcoin/bitcoin#23683.
On master (013daed9ac) it is not obvious that `CheckSequenceLocksAtTip()` function can modify its `LockPoints* lp` parameter which leads to https://github.com/bitcoin/bitcoin/pull/22677#discussion_r762040101.
This PR:
- separates the lockpoint calculate logic from `CheckSequenceLocksAtTip()` function into a new `CalculateLockPointsAtTip()` one
- cleans up the `CheckSequenceLocksAtTip()` function interface
- makes code easier to reason about (hopefully)
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Tree-SHA512: 072c3fd9cd1e1b0e0bfc8960a67b01c80a9f16d6778f374b6944ade03a020415ce8b8ab2593b0f5e787059c8cf90af798290b4c826785d41955092f6e12e7486
36c201feb7 remove CBlockIndex copy construction (James O'Beirne)
Pull request description:
Copy construction of CBlockIndex objects is a footgun because of the
wide use of equality-by-pointer comparison in the code base. There are
also potential lifetime confusions of using copied instances, since
there are recursive pointer members (e.g. pprev).
(See also https://github.com/bitcoin/bitcoin/pull/24008#discussion_r891949166)
We can't just delete the copy constructors because they are used for
derived classes (CDiskBlockIndex), so we mark them protected.
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Tree-SHA512: b1cf9a1cb992464a4377dad609713eea63cc099435df374e4553bfe62d362a4eb5e3c6c6649177832f38c0905b23841caf9d62196cef8e3084bfea0bfc26374b
Copy construction of CBlockIndex objects is a footgun because of the
wide use of equality-by-pointer comparison in the code base. There are
also potential lifetime confusions of using copied instances, since
there are recursive pointer references (e.g. pprev).
We can't just delete the copy constructors because they are used for
derived classes (CDiskBlockIndex), so we mark them protected.
Delete move constructors and declare the destructor to satisfy the
"rule of 5."
In order to prevent memory DoS, we must ensure that we don't accept a new
header into memory until we've performed anti-DoS checks, such as verifying
that the header is part of a sufficiently high work chain. This commit adds a
new argument to AcceptBlockHeader() so that we can ensure that all call-sites
which might cause a new header to be accepted into memory have to grapple with
the question of whether the header is safe to accept, or needs further
validation.
This patch also fixes two places where low-difficulty-headers could have been
processed without such validation (processing an unrequested block from the
network, and processing a compact block).
Credit to Niklas Gögge for noticing this issue, and thanks to Sjors Provoost
for test code.
9376a6dae4 refactor: make active_chain_tip a reference (Aurèle Oulès)
Pull request description:
This PR fixes a TODO introduced in #21055.
Makes `active_chain_tip` argument in `CheckFinalTxAtTip` function a reference instead of a pointer.
ACKs for top commit:
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Tree-SHA512: c36d1769e0b9598b7f79334704b26b73e958d54caa3bd7e4eff954f3964fcf3f5e3a44a5a760497afad51b76e1614c86314fe035e4083c855e3574a620de7f4d
...also adjust callers
Changes:
- In BlockAssembler::CreateNewBlock, we now only lock m_mempool->cs and
call addPackageTxs if m_mempool is not nullptr
- BlockAssembler::addPackageTxs now takes in a mempool reference, and is
annotated to require that mempool's lock.
- In TestChain100Setup::CreateBlock and generateblock, don't construct
an empty mempool, just pass in a nullptr for mempool
This decouples validation.cpp from netaddress.cpp (transitively,
timedata.cpp, and asmap.cpp).
This is important for libbitcoinkernel as:
- There is no reason for the consensus engine to be coupled with
netaddress, timedata, and asmap
- Users of libbitcoinkernel can now easily supply their own
std::function that provides the adjusted time.
See the src/Makefile.am changes for some satisfying removals.
