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
