59fd053dac
75f64e50c6test: exercise node abort on UTXO deserialization failure (furszy)4652cd0d82txdb: detect UTXO deserialization errors via CDBWrapper::TryRead() (furszy)5dfbb91b6cdbwrapper: add TryRead() to distinguish errors from valid outcomes (furszy)f78834fac9test: add missing coverage for CDBWrapper::Read() errors (furszy) Pull request description: Early note: the majority of this PR consists of test coverage. The changes per se are small. If a UTXO entry on disk can't be deserialized, the node currently treats it as if the coin wouldn't exist instead of aborting with an error. A non-existing coin has a very specific meaning for consensus: any block that spends it would be permanently rejected as invalid (`BLOCK_FAILED_VALID`), silently forking the node from the rest of the network. This can't currently be triggered in practice (details below), but it's still the wrong behavior. The root cause is that `CDBWrapper::Read()` returns `false` for both missing entries and deserialization failures, so `CCoinsViewDB::GetCoin()` has no way to tell them apart. `CCoinsViewErrorCatcher` was built to catch database read errors and abort, but it never fires during deserialization errors because `CDBWrapper::Read()` swallows the exception before it can propagate. This [comment](8a8edc8d88/src/coins.cpp (L398-L411)) in `ExecuteBackedWrapper()` spells out the code intent very clearly. As mentioned initially, this can't happen in practice today. It would require either a bug in the coin serialization path, or a memory corruption before the data reaches LevelDB (at which point we have bigger problems). Random disk-level bit flips are caught earlier by LevelDB's verification (`verify_checksums=true`, enabled by default), which already propagates correctly as `DB_INTERNAL_ERROR`. Regardless, a db read issue should never be silently misinterpreted as a consensus violation. This PR adds `CDBWrapper::TryRead()`, which returns a `ReadStatus` that lets callers discriminate between all possible outcomes. `CCoinsViewDB::GetCoin()` switches on the result and throws on any error, letting `ExecuteBackedWrapper()` do what it was designed to do. `CDBWrapper::Read()` becomes a thin wrapper over `TryRead()`, preserving backward compatibility for all other callers (so we don't have to change non-consensus code here). `PeekCoin()` is also covered, as it delegates to `CCoinsViewDB::GetCoin()` at the database level. The idea of the PR is to go slowly over the code changes, first commit locks-in the current `CDBWrapper::Read()` behavior . The second adds `TryRead()` with tests for all four status codes. The third is the `CCoinsViewDB::GetCoin()` fix. The fourth is a functional that ensures the node aborts correctly instead of silently diverging. Testing Notes: Cherry-picking the functional test commit on master demonstrates the consensus split when the coin entry fails to deserialize. Extra Note: `CDBIterator::GetValue()` has the same silent-swallow pattern. Not consensus-critical. Should be addressed in a follow-up. ACKs for top commit: ajtowns: reACK75f64e50c6sedited: ACK75f64e50c6mzumsande: Code Review ACK [75f64e5](75f64e50c6) Tree-SHA512: 51b0114ea443544a2f1fbb8e63be6e1dff94d6f287221d566dbc98d666784a2b4c486acfb87eea5392bc1d092fb6d6dc0ff6782bcdccdcf15939281c895e384d
Bitcoin Core integration/staging tree
For an immediately usable, binary version of the Bitcoin Core software, see https://bitcoincore.org/en/download/.
What is Bitcoin Core?
Bitcoin Core connects to the Bitcoin peer-to-peer network to download and fully validate blocks and transactions. It also includes a wallet and graphical user interface, which can be optionally built.
Further information about Bitcoin Core is available in the doc folder.
License
Bitcoin Core is released under the terms of the MIT license. See COPYING for more information or see https://opensource.org/license/MIT.
Development Process
The master branch is regularly built (see doc/build-*.md for instructions) and tested, but it is not guaranteed to be
completely stable. Tags are created
regularly from release branches to indicate new official, stable release versions of Bitcoin Core.
The https://github.com/bitcoin-core/gui repository is used exclusively for the development of the GUI. Its master branch is identical in all monotree repositories. Release branches and tags do not exist, so please do not fork that repository unless it is for development reasons.
The contribution workflow is described in CONTRIBUTING.md and useful hints for developers can be found in doc/developer-notes.md.
Testing
Testing and code review is the bottleneck for development; we get more pull requests than we can review and test on short notice. Please be patient and help out by testing other people's pull requests, and remember this is a security-critical project where any mistake might cost people lots of money.
Automated Testing
Developers are strongly encouraged to write unit tests for new code, and to
submit new unit tests for old code. Unit tests can be compiled and run
(assuming they weren't disabled during the generation of the build system) with: ctest. Further details on running
and extending unit tests can be found in /src/test/README.md.
There are also regression and integration tests, written
in Python.
These tests can be run (if the test dependencies are installed) with: build/test/functional/test_runner.py
(assuming build is your build directory).
The CI (Continuous Integration) systems make sure that every pull request is tested on Windows, Linux, and macOS. The CI must pass on all commits before merge to avoid unrelated CI failures on new pull requests.
Manual Quality Assurance (QA) Testing
Changes should be tested by somebody other than the developer who wrote the code. This is especially important for large or high-risk changes. It is useful to add a test plan to the pull request description if testing the changes is not straightforward.
Translations
Changes to translations as well as new translations can be submitted to Bitcoin Core's Transifex page.
Translations are periodically pulled from Transifex and merged into the git repository. See the translation process for details on how this works.
Important: We do not accept translation changes as GitHub pull requests because the next pull from Transifex would automatically overwrite them again.