chain_start can never be null, so it's better to pass it as a reference
rather than a raw pointer
Also slightly reformat HeaderSyncState constructor to make clang-format
happy
Lastly, remove `const` from `chain_start` declaration in
headers_sync_chainwork_tests, to work aroud a false-positive
dangling-reference warning in gcc 13.0
Co-Authored-By: maflcko <6399679+maflcko@users.noreply.github.com>
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.
01cc20f330 test: improve coverage for a resolved stalling situation (Martin Zumsande)
9af6daf07e test: remove magic number when checking for blocks that have arrived (Martin Zumsande)
3069d66dca p2p: During block download, adjust pindexLastCommonBlock better (Martin Zumsande)
Pull request description:
As described in #32179, `pindexLastCommonBlock` is updated later than necessary
in master.
In case of a linear chain with no forks, it can be moved forward at the beginning of
`FindNextBlocksToDownload`, so that the updated value can be used to better estimate `nWindowEnd`.
This helps the node to request all blocks from peers within the correct 1024-block-window and avoids peers being incorrectly marked as stallers.
I also changed `p2p_ibd_stalling.py` to cover the situation after a resolved situation, making sure that no additional peers are marked for stalling.
Fixes#32179
ACKs for top commit:
Crypt-iQ:
crACK 01cc20f330
stringintech:
re-ACK 01cc20f
achow101:
ACK 01cc20f330
sipa:
utACK 01cc20f330
Tree-SHA512: a97f7a7ef5ded538ee35576e04b3fbcdd46a6d0189c7ba3abacc6e0d81e800aac5b0c2d2565d0462ef6fd4acc751989f577fd6adfd450171a7d6ab26f437df32
No need to pass consensusParams, as CheckHeadersPoW already has access
to m_chainparams.GetConsensus()
Co-Authored-By: maflcko <6399679+maflcko@users.noreply.github.com>
Avoid the need to construct a CBlockIndex object just to compute work for a header,
when its nBits value suffices for that.
Co-Authored-By: Pieter Wuille <pieter@wuille.net>
Just don't call this function when it won't have any effect.
Note that we can't remove the LookupBlockIndex call, since `last_received_header`
is needed to check if new headers were received (`received_new_header`).
65a10fc3c5 p2p: add assertion for BlockTransactionsRequest indexes (frankomosh)
58be359f6b fuzz: add a target for DifferenceFormatter Class (frankomosh)
Pull request description:
Adds a fuzz test for the [`DifferenceFormatter`](e3f416dbf7/src/blockencodings.h (L22-L42)) (used in [`BlockTransactionsRequest`](https://github.com/bitcoin/bitcoin/blob/master/src/blockencodings.h#L44-L54), [BIP 152](https://github.com/bitcoin/bips/blob/master/bip-0152.mediawiki)). The DifferenceFormatter class implements differential encoding for compact block transactions (BIP 152). This PR ensures that its strictly-monotonic property is maintained. It complements the tests in [`blocktransactionsrequest_deserialize`](9703b7e6d5/src/test/fuzz/deserialize.cpp (L314)).
Additionally, there's an added invariant check after GETBLOCKTXN deserialization in `net_processing.cpp`.
ACKs for top commit:
Crypt-iQ:
tACK 65a10fc3c5
achow101:
ACK 65a10fc3c5
dergoegge:
Code review ACK 65a10fc3c5
Tree-SHA512: 70659cf045e99bb5f753763c7ddac094cb2883c202c899276cbe616889afa053b2d5e831f99d6386d4d1e4118cd35fa0b14b54667853fe067f6efe2eb77b4097
cc5dda1de3 headerssync: Make HeadersSyncState more flexible and move constants (Hodlinator)
8fd1c2893e test(headerssync): Test returning of pow_validated_headers behavior (Hodlinator)
7b00643ef5 test(headerssync): headers_sync_chainwork test improvements (Hodlinator)
04eeb9578c doc(test): Improve comments (Hodlinator)
fe896f8faa refactor(test): Store HeadersSyncState on the stack (Hodlinator)
f03686892a refactor(test): Break up headers_sync_state (Hodlinator)
e984618d0b refactor(headerssync): Process spans of headers (Hodlinator)
a4ac9915a9 refactor(headerssync): Extract test constants ahead of breakup into functions (Hodlinator)
Pull request description:
### Background
As part of the release process we often run *contrib/devtools/headerssync-params.py* and increase the values of the constants `HEADER_COMMITMENT_PERIOD` and `REDOWNLOAD_BUFFER_SIZE` in *src/headerssync.cpp* as per *doc/release-process.md* (example: 11a2d3a63e). This helps fine tune the memory consumption per `HeadersSyncState`-instance in the face of malicious peers.
(The `REDOWNLOAD_BUFFER_SIZE`/`HEADER_COMMITMENT_PERIOD` ratio determines how many Headers Sync commitment bits must match between PRESYNC & REDOWNLOAD phases before we start permanently storing headers from a peer. For more details see comments in *src/headerssync.h* and *contrib/devtools/headerssync-params.py*).
### Problem: Not feeding back headers until completing sync
During v30 release process #33274 made `REDOWNLOAD_BUFFER_SIZE` exceed the `target_blocks` constant used to control the length of chains generated for testing Headers Sync (`15000`, *headers_sync_chainwork_tests.cpp*).
The `HeadersSyncState::m_redownloaded_headers`-buffer now does not reach the `REDOWNLOAD_BUFFER_SIZE`-threshold during those unit tests. As a consequence `HeadersSyncState::PopHeadersReadyForAcceptance()` will not start feeding back headers until the PoW threshold has been met. While this will not cause the unit test to start failing on master, it means we have gone from testing behavior that resembles mainnet (way more than `REDOWNLOAD_BUFFER_SIZE` headers to reach the PoW limit), to behavior that is not possible/expected there.
### Solution
Avoid testing this unrealistic condition of completing Headers Sync before reaching `REDOWNLOAD_BUFFER_SIZE` by making tests able to define their own values through the new `HeadersSyncParams` instead of having them hard-coded for all chains & tests.
### Commits
* First 6 commits refactor and improve the unit tests in order to clarify latter changes.
* We then add checks for the behavior around the `REDOWNLOAD_BUFFER_SIZE` threshold.
* The main change: we extract the section from *headerssync.cpp* containing the constants to *kernel/chainparams.cpp*, making `HeadersSyncState` no longer hard-coded to mainnet.
### Notes
This PR used to be called "headerssync: Preempt unrealistic unit test behavior".
ACKs for top commit:
l0rinc:
reACK cc5dda1de3
marcofleon:
code review ACK cc5dda1de3
danielabrozzoni:
reACK cc5dda1de3
Tree-SHA512: ccc824dcbbb8ad5ae98c3bf5808b38467aac0230739898a758c9b939eecd74f982df088fa0ba81cc1c1732f19a607b135a6e9577bb9fcf7f8570567ce92f66e6
Simplify and improve the logic for calculating pindexLastCommonBlock, in order to calculate
nWindowEnd better.
The previous logic would not take into account when the chain tip had moved forward, so that
FindNextBlocks could iterate over many blocks already downloaded and
connected, which could result in blocks not being requested for download that should have been
requested, and peers being wrongly marked as staller.
It also removes extra logic from commit 49d569cb1f
for the situation right after a snapshot was loaded:
After snapshot loading, our tip becomes the snapshot block.
For peers that have the most-work chain, which inlcludes the snapshot,
our tip is an ancestor of the peer's best block, hence the general
advancement logic will move pindexLastCommonBlock
from any pre-snapshot position to the snapshot height automatically.
Co-authored-by: stringintech <stringintech@gmail.com>
Co-authored-by: Pieter Wuille <pieter@wuille.net>
0f7d4ee4e8 p2p: Use different inbound inv timer per network (Martin Zumsande)
94db966a3b net: use generic network key for addrcache (Martin Zumsande)
Pull request description:
Currently, `NextInvToInbounds` schedules each round of `inv` at the same time for all inbound peers. It's being done this way because with a separate timer per peer (like it's done for outbounds), an attacker could do multiple connections to learn about the time a transaction arrived. (#13298).
However, having a single timer for inbounds of all networks is also an obvious fingerprinting vector: Connecting to a suspected pair of privacy-network and clearnet addresses and observing the `inv` pattern makes it trivial to confirm or refute that they are the same node.
This PR changes it such that a separate timer is used for each network.
It uses the existing method from `getaddr` caching and generalizes it to be saved in a new field `m_network_key` in `CNode` which will be used for both `getaddr` caching and `inv` scheduling, and can also be used for any future anti-fingerprinting measures.
ACKs for top commit:
sipa:
utACK 0f7d4ee4e8
stratospher:
reACK 0f7d4ee.
naiyoma:
Tested ACK 0f7d4ee4e8
danielabrozzoni:
reACK 0f7d4ee4e8
Tree-SHA512: e197c3005b2522051db432948874320b74c23e01e66988ee1ee11917dac0923f58c1252fa47da24e68b08d7a355d8e5e0a3ccdfa6e4324cb901f21dfa880cd9c
Currently nodes schedule their invs to all inbound peers at the same time.
It is trivial to make use this timing pattern for fingerprinting
identities on different networks. Using a separate timers for each network will
make the fingerprinting harder.
2738b63e02 test: validate behaviour of getpeerinfo last_inv_sequence and inv_to_send (Anthony Towns)
77b2ebb811 rpc/net: report per-peer last_inv_sequence (Anthony Towns)
adefb51c54 rpc/net: add per-peer inv_to_send sizes (Anthony Towns)
Pull request description:
Adds per-peer entries to `getpeerinfo` for the size of the inv_to_send queue and the mempool sequence number as at the last INV. Can be helpful for debugging tx relay performance and privacy/fingerprinting issues.
ACKs for top commit:
sipa:
utACK 2738b63e02
instagibbs:
ACK 2738b63e02
Tree-SHA512: e3c9c52e8e38b099d405a177ffba6783c5821cc5ce1432b98218843e00906986ce2141dcd5b04a67006c328211a672e519fa3390e012688499bfc9ac99767599
b81f37031c p2p: Increase tx relay rate (Anthony Towns)
Pull request description:
In the presence of smaller transactions on the network, blocks can sustain a higher relay rate than 7tx/second. In this event, the per-peer inventory queues can grow too large.
This commit bumps the rate up to 14 tx/s (for inbound peers), increasing the safety margin by a factor of 2.
Outbound peers continue to receive relayed transactions at 2.5x the rate of inbound peers, for a rate of 35tx/second.
ACKs for top commit:
sipa:
ACK b81f37031c
achow101:
ACK b81f37031c
darosior:
utACK b81f37031c.
glozow:
utACK b81f37031c
Tree-SHA512: 854ea0824d5f4c629f1dceb9ee61cc9226c8f0d4d26664737e68db917f65341d4800362ab55ed32673db920b2b59aa116b4cb9ee063367b2e43c94a904b41c08
Move calculated constants from the top of src/headerssync.cpp into src/kernel/chainparams.cpp.
Instead of being hardcoded to mainnet parameters, HeadersSyncState can now vary depending on chain or test. (This means we can reset TARGET_BLOCKS back to the nice round number of 15'000).
Signet and testnets got new HeadersSyncParams constants through temporarily altering headerssync-params.py with corresponding GENESIS_TIME and MINCHAINWORK_HEADERS (based off defaultAssumeValid block height comments, corresponding to nMinimumChainWork). Regtest doesn't have a default assume valid block height, so the values are copied from Testnet 4. Since the constants only affect memory usage, and have very low impact unless dealing with a largely malicious chain, it's not that critical to keep updating them for non-mainnet chains.
GENESIS_TIMEs (UTC):
Testnet3: 1296688602 = datetime(2011, 2, 2)
Testnet4: 1714777860 = datetime(2024, 5, 3)
Signet: 1598918400 = datetime(2020, 9, 1)
Previously in debug builds, this would cause an Assume crash if
FillBlock had been called previously. This could happen when multiple
blocktxn messages were received.
Co-Authored-By: Greg Sanders <gsanders87@gmail.com>
1d9f1cb4bd kernel: improve BlockChecked ownership semantics (stickies-v)
9ba1fff29e kernel: refactor: ConnectTip to pass block pointer by value (stickies-v)
Pull request description:
Subscribers to the BlockChecked validation interface event may need access to the block outside of the callback scope. Currently, this is only possible by copying the block, which makes exposing this validation interface event publicly either cumbersome or with significant copy overhead.
By using shared_ptr, we make the shared ownership explicit and allow users to safely use the block outside of the callback scope. By using a const-ref shared_ptr, no atomic reference count cost is incurred if a subscriber does not require block ownership.
For example: in #30595, this would allow us to drop the `kernel_BlockPointer` handle entirely, and generalize everything into `kernel_Block`. This PoC is implemented in https://github.com/stickies-v/bitcoin/commits/kernel/remove-blockpointer/.
---
### Performance
I have added a benchmark in a [separate branch](https://github.com/stickies-v/bitcoin/commits/2025-07/validation-interface-ownership-benched/), to ensure this change does not lead to a problematic performance regression. Since most of the overhead comes from the subscribers, I have added scenarios for `One`, `Two`, and `Ten` subscribers. From these results, it appears there is no meaningful performance difference on my machine.
When `BlockChecked()` takes a `const CBlock&` reference _(master)_:
| ns/op | op/s | err% | total | benchmark
|--------------------:|--------------------:|--------:|----------:|:----------
| 170.09 | 5,879,308.26 | 0.3% | 0.01 | `BlockCheckedOne`
| 1,603.95 | 623,460.10 | 0.5% | 0.01 | `BlockCheckedTen`
| 336.00 | 2,976,173.37 | 1.1% | 0.01 | `BlockCheckedTwo`
When `BlockChecked()` takes a `const std::shared_ptr<const CBlock>&` _(this PR)_:
| ns/op | op/s | err% | total | benchmark
|--------------------:|--------------------:|--------:|----------:|:----------
| 172.20 | 5,807,155.33 | 0.1% | 0.01 | `BlockCheckedOne`
| 1,596.79 | 626,254.52 | 0.0% | 0.01 | `BlockCheckedTen`
| 333.38 | 2,999,603.17 | 0.3% | 0.01 | `BlockCheckedTwo`
ACKs for top commit:
achow101:
ACK 1d9f1cb4bd
w0xlt:
reACK 1d9f1cb4bd
ryanofsky:
Code review ACK 1d9f1cb4bd. These all seem like simple changes that make sense
TheCharlatan:
ACK 1d9f1cb4bd
yuvicc:
Code Review ACK 1d9f1cb4bd
Tree-SHA512: 7ed0cccb7883dbb1885917ef749ab7cae5d60ee803b7e3145b2954d885e81ba8c9d5ab1edb9694ce6b308235c621094c029024eaf99f1aab1b47311c40958095
de0675f9de refactor: Move `transaction_identifier.h` to primitives (marcofleon)
6f068f65de Remove implicit uint256 conversion and comparison (marcofleon)
9c24cda72e refactor: Convert remaining instances from uint256 to Txid (marcofleon)
d2ecd6815d policy, refactor: Convert uint256 to Txid (marcofleon)
f6c0d1d231 mempool, refactor: Convert uint256 to Txid (marcofleon)
aeb0f78330 refactor: Convert `mini_miner` from uint256 to Txid (marcofleon)
326f244724 refactor: Convert RPCs and `merkleblock` from uint256 to Txid (marcofleon)
49b3d3a92a Clean up `FindTxForGetData` (marcofleon)
Pull request description:
This is the final leg of the [type safety refactor](https://github.com/bitcoin/bitcoin/pull/32189).
All of these changes are straightforward `uint256` --> `Txid` along with any necessary explicit conversions. Also, `transaction_identifier.h` is moved to primitives in the last commit, as `Txid` and `Wtxid` become fundamental types after this PR.
ACKs for top commit:
stickies-v:
re-ACK de0675f9de, no changes since a20724d926d5844168c6a13fa8293df8c8927efe except address review nits.
janb84:
re ACK de0675f9de
dergoegge:
re-ACK de0675f9de
theStack:
Code-review ACK de0675f9de
Tree-SHA512: 2413160fca7ab146a8d79d18ce3afcf7384cacc73c513d41928904aa453b4dd7a350064cee71e9c5d015da5904c7c81ac17603e50a47441ebc5b0c653235dd08
These remaining miscellaneous changes were identified by commenting out
the `operator const uint256&` conversion and the `Compare(const uint256&)`
method from `transaction_identifier.h`.
Do not discourage nodes even when they send us consensus invalid
transactions.
Because we do not discourage nodes for transactions we consider
non-standard, we don't get any DoS protection from this check in
adversarial scenarios, so remove the check entirely both to simplify the
code and reduce the risk of splitting the network due to changes in tx
relay policy.
c0642e558a [fuzz] fix latency score check in txorphan_protected (glozow)
3d4d4f0d92 scripted-diff: rename "ann" variables to "latency_score" (monlovesmango)
3b92448923 [doc] comment fixups for orphanage changes (glozow)
1384dbaf6d [config] emit warning for -maxorphantx, but allow it to be set (glozow)
b10c55b298 fix up TxOrphanage lower_bound sanity checks (glozow)
cfd71c6704 scripted-diff: rename TxOrphanage outpoints index (glozow)
edb97bb3f1 [logging] add logs for inner loop of LimitOrphans (glozow)
8a58d0e87d scripted-diff: rename OrphanTxBase to OrphanInfo (glozow)
cc50f2f0df [cleanup] replace TxOrphanage::Size() with CountUniqueOrphans (glozow)
ed24e01696 [optimization] Maintain at most 1 reconsiderable announcement per wtxid (Pieter Wuille)
af7402ccfa [refactor] make TxOrphanage keep itself trimmed (glozow)
d1fac25ff3 [doc] 31829 release note (glozow)
Pull request description:
Followup to #31829:
- Release notes
- Have the orphanage auto-trim itself whenever necessary (and test changes) https://github.com/bitcoin/bitcoin/pull/31829#discussion_r2169508690
- Reduce duplicate reconsiderations by keeping track of which txns are already reconsiderable so we only mark it for reconsideration for 1 peer at a time https://github.com/bitcoin/bitcoin/pull/31829#issuecomment-3001627814
- Rename `OrphanTxBase` to `OrphanInfo`
- Get rid of `Size()` method by replacing all calls with `CountUniqueOrphans`
- Rename outpoints index since they point to wtxids, not iterators https://github.com/bitcoin/bitcoin/pull/31829#discussion_r2205557613
- Add more logging in the `LimitOrphans` inner loop to make it easy to see which peers are being trimmed https://github.com/bitcoin/bitcoin/pull/31829#issuecomment-3074385460
ACKs for top commit:
sipa:
utACK c0642e558a
marcofleon:
Nice, ACK c0642e558a
Tree-SHA512: f298eae92cf906ed5e4f15a24eeffa7b9e620bcff457772cd77522dd9f0b3b183ffc976871b1b0e6fe93009e64877d518e53d4b9e186e0df58fc16d17f6de90a
Subscribers to the BlockChecked validation interface event may need
access to the block outside of the callback scope. Currently, this
is only possible by copying the block, which makes exposing this
validation interface event publicly either cumbersome or with significant
copy overhead.
By using shared_ptr, we make the shared ownership explicit and allow
users to safely use the block outside of the callback scope.
Simplifies `m_tx_inventory_to_send` a bit by making it a set of Wtxids.
Wtxid relay is prevalent throughout the network, so the complexity of
dealing with a GenTxid in this data structure isn't necessary.
For peers that aren't wtxid relay, the txid is now retrieved from our
mempool entry when the inv is constructed.
1cb2399703 doc: clarify the GetAddresses/GetAddressesUnsafe documentation (Daniela Brozzoni)
e5a7dfd79f p2p: rename GetAddresses -> GetAddressesUnsafe (Daniela Brozzoni)
Pull request description:
Rename GetAddresses to GetAddressesUnsafe to make it clearer that this function should only be used in trusted contexts. This helps avoid accidental privacy leaks by preventing the uncached version from being used in non-trusted scenarios, like P2P.
Additionally, better reflect in the documentation that the two methods should be used in different contexts.
Also update the outdated "call the function without a parameter" phrasing in the cached version. This wording was accurate when the cache was introduced in #18991, but became outdated after later commits (f26502e9fc, 81b00f8780) added parameters to each
function, and the previous commit changed the function naming completely.
ACKs for top commit:
stickies-v:
re-ACK 1cb2399703
l0rinc:
ACK 1cb2399703
luisschwab:
ACK 1cb2399703
brunoerg:
ACK 1cb2399703
theStack:
Code-review ACK 1cb2399703
mzumsande:
Code review ACK 1cb2399703
Tree-SHA512: 02c05d88436abcdfabad994f47ec5144e9ba47668667a2c1818f57bf8710727505faf8426fd0672c63de14fcf20b96f17cea2acc39fe3c1f56abbc2b1a9e9c23
Rename GetAddresses to GetAddressesUnsafe to make it clearer that this
function should only be used in trusted contexts. This helps avoid
accidental privacy leaks by preventing the uncached version from being
used in non-trusted scenarios, like P2P.
Move towards a model where TxOrphanage is initialized with limits that
it remembers throughout its lifetime.
Remove the param. Limiting by number of unique orphans will be removed
in a later commit.
Now that -maxorphantx is gone, this does not change the node behavior.
The parameter is only used in tests.
a60f863d3e scripted-diff: Replace GenTxidVariant with GenTxid (marcofleon)
c8ba199598 Remove old GenTxid class (marcofleon)
072a198ea4 Convert remaining instances of GenTxid to GenTxidVariant (marcofleon)
1b528391c7 Convert `txrequest` to GenTxidVariant (marcofleon)
bde4579b07 Convert `txdownloadman_impl` to GenTxidVariant (marcofleon)
c876a892ec Replace GenTxid with Txid/Wtxid overloads in `txmempool` (marcofleon)
de858ce2be move-only: make GetInfo a private CTxMemPool member (stickies-v)
eee473d9f3 Convert `CompareInvMempoolOrder` to GenTxidVariant (marcofleon)
243553d590 refactor: replace get_iter_from_wtxid with GetIter(const Wtxid&) (stickies-v)
fcf92fd640 refactor: make CTxMemPool::GetIter strongly typed (marcofleon)
11d28f21bb Implement GenTxid as a variant (marcofleon)
Pull request description:
Part of the [type safety refactor](https://github.com/bitcoin/bitcoin/pull/32189).
This PR changes the GenTxid class to a variant, which holds both Txids and Wtxids. This provides compile-time type safety and eliminates the manual type check (bool m_is_wtxid). Variables that can be either a Txid or a Wtxid are now using the new GenTxid variant, instead of uint256.
ACKs for top commit:
w0xlt:
ACK a60f863d3e
dergoegge:
Code review ACK a60f863d3e
maflcko:
review ACK a60f863d3e🎽
theStack:
Code-review ACK a60f863d3e
Tree-SHA512: da9b73b7bdffee2eb9281a409205519ac330d3336094d17681896703fbca8099608782c9c85801e388e4d90af5af8abf1f34931f57bbbe6e9674d802d6066047
Now that we are storing `CTxMemPool::CompareDepthAndScore` parameters using
`std::variant` we have no portable zero-overhead way of accessing them,
so use `std::visit` and drop `bool wtxid` in-parameter.
Co-authored-by: stickies-v <stickies-v@protonmail.com>
28299ce776 p2p: remove vestigial READ_STATUS_CHECKBLOCK_FAILED (Greg Sanders)
bac9ee4830 p2p: Add witness mutation check inside FillBlock (Greg Sanders)
Pull request description:
Since #29412, we have not allowed mutated blocks to continue being processed immediately the block is received, but this is only done for the legacy BLOCK message.
Extend these checks as belt-and-suspenders to not allow similar mutation strategies to affect relay by honest peers by applying the check inside `PartiallyDownloadedBlock::FillBlock`, immediately before returning `READ_STATUS_OK`.
ACKs for top commit:
Crypt-iQ:
ACK 28299ce776
achow101:
ACK 28299ce776
stratospher:
ACK 28299ce7.
dergoegge:
Code review ACK 28299ce776
Tree-SHA512: 883d7c12ca096234b425e6fe12e46b0611607600916e6ac8d1c8112224aa76924b7b074754910163ac2ec15379075d618a9ece3642649ac7629cddb0d4e432ea
9341b5333a blockstorage: make block read hash checks explicit (Lőrinc)
2371b9f4ee test/bench: verify hash in `ComputeFilter` reads (Lőrinc)
5d235d50d6 net: assert block hash in `ProcessGetBlockData` and `ProcessMessage` (Lőrinc)
Pull request description:
A follow-up to https://github.com/bitcoin/bitcoin/pull/32487#discussion_r2094072165, after which validating the hash of a read block from disk doesn't incur the cost of calculating its hash anymore.
### Summary
This PR adds explicit checks that the read block header's hash matches the one we were expecting.
### Context
After the previous PR, validating a block's hash during read operations became essentially free. This PR leverages that by requiring callers to provide a block's expected hash (or `std::nullopt`), preventing silent failures caused by corrupted or mismatched data. Most `ReadBlock` usages were updated with expected hashes and now fail on mismatch.
### Changes
* added hash assertions in `ProcessGetBlockData` and `ProcessMessage` to validate that the block read from disk matches the expected hash;
* updated tests and benchmark to pass the correct block hash to `ReadBlock()`, ensuring the hash validation is tested - or none if we already expect PoW failure;
* removed the default value for `expected_hash`, requiring an explicit hash for all block reads.
### Why is the hash still optional (but no longer has a default value)
* for header-error tests, where the goal is to trigger failures early in the parsing process;
* for out-of-order orphan blocks, where the child hash isn't available before the initial disk read.
ACKs for top commit:
maflcko:
review ACK 9341b5333a🕙
achow101:
ACK 9341b5333a
hodlinator:
ACK 9341b5333a
janb84:
re ACK 9341b5333a
Tree-SHA512: cf1d4fff4c15e3f8898ec284929cb83d7e747125d4ee759e77d369f1716728e843ef98030be32c8d608956a96ae2fbefa0e801200c333b9eefd6c086ec032e1f
The non-recent-block code path in `ProcessGetBlockData` already has `inv.hash` available (equaling `pindex->GetBlockHash()`).
Pass it to `ReadBlock()` and assert that the on-disk header matches the requested hash.
The `GETBLOCKTXN` message handler in `ProcessMessage` receives `req.blockhash` from the peer (equaling `pindex->GetBlockHash()`).
Pass this hash to `ReadBlock()` for verification and assert that the index lookup matches.
Co-authored-by: TheCharlatan <seb.kung@gmail.com>
Co-authored-by: Hodlinator <172445034+hodlinator@users.noreply.github.com>
