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:
maflcko:
ACK 429ec1aaaa 🐿
glozow:
ACK 429ec1aaaa
shaavan:
ACK 429ec1aaaa💯
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)
ACKs for top commit:
achow101:
ACK 75db62ba4c
stickies-v:
re-ACK 75db62b
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.
ACKs for top commit:
ajtowns:
ACK 36c201feb7 - code review only
MarcoFalke:
re-ACK 36c201feb7 🏻
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:
dongcarl:
ACK 9376a6dae4
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.
308dd2e93e Sanity assert GetAncestor() != nullptr where appropriate (Adam Jonas)
Pull request description:
Re-opening #17232. I have rebased the PR and addressed jonatack's nit suggestions.
Add sanity asserts for return value of `CBlockIndex::GetAncestor()` where appropriate.
In validation.cpp `CheckSequenceLocks`, check the return value of `tip->GetAncestor(maxInputHeight)` stored into `lp->maxInputBlock`. If it ever returns `nullptr` because the ancestor isn't found, it's going to be a bad bug to keep going, since a `LockPoints` object with the `maxInputBlock` member set to `nullptr` signifies no relative lock time.
In the other places, the added asserts would prevent accidental dereferencing of a null pointer which is undefined behavior.
Co-Authored-By: Adam Jonas <jonas@chaincode.com>
Co-Authored-By: danra <danra@users.noreply.github.com>
ACKs for top commit:
jonatack:
ACK 308dd2e93e
Tree-SHA512: 5bfdaab1499607ae2c3cd3e2e9e8c37850bfd0e327e680f4e36c81f9c6d98a543af78ecfac1ab0e06325d264412615a04d52005875780c7db2a4d81bd2d2259a
Add sanity asserts for return value of `CBlockIndex::GetAncestor()` where appropriate.
In validation.cpp `CheckSequenceLocks`, check the return value of `tip->GetAncestor(maxInputHeight)` stored into `lp->maxInputBlock`. If it ever returns `nullptr` because the ancestor isn't found, it's going to be a bad bug to keep going, since a `LockPoints` object with the `maxInputBlock` member set to `nullptr` signifies no relative lock time.
In the other places, the added asserts would prevent accidental dereferencing of a null pointer which is undefined behavior.
Co-Authored-By: Aurèle Oulès <aurele@oules.com>
Co-Authored-By: danra <danra@users.noreply.github.com>
fa8d4d9128 scripted-diff: Clarify CheckFinalTxAtTip name (MarcoFalke)
fa4e30b0f3 policy: Remove unused locktime flags (MarcoFalke)
Pull request description:
The locktime flags have many issues:
* They are passed in by a default argument, which is fragile. It has already lead to bugs like the one fixed in commit e30b6ea194.
* They are negative (signed), which doesn't make sense for flags (unsigned in general). According to the review comments when the code was added: "The max on the flags is a fairly weird operation." (https://github.com/bitcoin/bitcoin/pull/6566#issuecomment-150310861)
* No call site relies on the default argument and they all pass in a single compile-time constant, rendering most of the code dead and untested.
* The dead code calls `GetAdjustedTime` (network adjusted time), which has its own issues. See https://github.com/bitcoin/bitcoin/issues/4521
Fix all issues by removing them
ACKs for top commit:
ajtowns:
ACK fa8d4d9128
theStack:
Code-review ACK fa8d4d9128
glozow:
ACK fa8d4d9128, agree the default arg `flags` is a massive footgun and just setting max flags is weird. Adding `AtTip` to the names makes sense to me, since they're both testing for *next* block and only ever used for {,re}addition to mempool.
Tree-SHA512: 79f4a52f34909eb598d88bbae7afe8abe5f85f45c128483d16aa83dacd0e5579e561b725d01b1e9a931d1821012a51ad2bc6fb2867f8d09ee541f9d234d696f8
This checks finality at the current Tip, so clarify this in its name.
-BEGIN VERIFY SCRIPT-
ren() { sed -i "s/\<$1\>/$2/g" $( git grep -l "$1" ./src/ ) ; }
ren CheckSequenceLocks CheckSequenceLocksAtTip
ren CheckFinalTx CheckFinalTxAtTip
-END VERIFY SCRIPT-
Allow CheckSequenceLocks to use heights and coins from any CoinsView and
CBlockIndex provided. This means that CheckSequenceLocks() doesn't need
to hold the mempool lock or cs_main. The caller is responsible for
ensuring the CoinsView and CBlockIndex are consistent before passing
them in. The typical usage is still to create a CCoinsViewMemPool from
the mempool and grab the CBlockIndex from the chainstate tip.
