335798c496
86d7135e36efd39781cf4c969011df99f0cbb69d [p2p] only attempt 1p1c when both txns provided by the same peer (glozow) f7658d9b1475ecaa5cb8e543e5c66a3a3a2dc1fb [cleanup] remove p2p_inv from AddTxAnnouncement (glozow) 063c1324c143d98e6d5108bb51b3ca59b45f9b85 [functional test] getorphantxs reflects multiple announcers (glozow) 0da693f7e129fccaecf9a2c177083d2e80d37781 [functional test] orphan handling with multiple announcers (glozow) b6ea4a9afe2d8bbf49b6b6c42f0a3ce4390c4535 [p2p] try multiple peers for orphan resolution (glozow) 1d2e1d709ce3d95d409254c860347bc3fedf30e1 [refactor] move creation of unique_parents to helper function (glozow) c6893b0f0b7b205c8da4b9d281a55c9eb843b582 [txdownload] remove unique_parents that we already have (glozow) 163aaf285af91b49c2d788463dc1e1654c88ade6 [fuzz] orphanage multiple announcer functions (glozow) 22b023b09da3e2fe00467c77b105a61c1961081f [unit test] multiple orphan announcers (glozow) 96c1a822a274689611f409246ef1573906b0083e [unit test] TxOrphanage EraseForBlock (glozow) 04448ce32a3bc4b6d12293f71e40333abe35c224 [txorphanage] add GetTx so that orphan vin can be read (glozow) e810842acda6fe56e0536ebecfbb9d17d26e1513 [txorphanage] support multiple announcers (glozow) 62a9ff187076686b39dca64ad4f2f439da0875d1 [refactor] change type of unique_parents to Txid (glozow) 6951ddcefd9e05f31ee7634bbfbf1d19e04ec00e [txrequest] GetCandidatePeers (glozow) Pull request description: Part of #27463. (Transaction) **orphan resolution** is a process that kicks off when we are missing UTXOs to validate an unconfirmed transaction. We currently request missing parents by txid; BIP 331 also defines a way to [explicitly request ancestors](https://github.com/bitcoin/bips/blob/master/bip-0331.mediawiki#handle-orphans-better). Currently, when we find that a transaction is an orphan, we only try to resolve it with the peer who provided the `tx`. If this doesn't work out (e.g. they send a `notfound` or don't respond), we do not try again. We actually can't, because we've already forgotten who else could resolve this orphan (i.e. all the other peers who announced the transaction). What is wrong with this? It makes transaction download less reliable, particularly for 1p1c packages which must go through orphan resolution in order to be downloaded. Can we fix this with BIP 331 / is this "duct tape" before the real solution? BIP 331 (receiver-initiated ancestor package relay) is also based on the idea that there is an orphan that needs resolution, but it's just a new way of communicating information. It's not inherently more honest; you can request ancestor package information and get a `notfound`. So ancestor package relay still requires some kind of procedure for retrying when an orphan resolution attempt fails. See the #27742 implementation which builds on this orphan resolution tracker to keep track of what packages to download (it just isn't rebased on this exact branch). The difference when using BIP 331 is that we request `ancpkginfo` and then `pkgtxns` instead of the parent txids. Zooming out, we'd like orphan handling to be: - Bandwidth-efficient: don't have too many requests out at once. As already implemented today, transaction requests for orphan parents and regular download both go through the `TxRequestTracker` so that we don't have duplicate requests out. - Not vulnerable to censorship: don't give up too easily, use all candidate peers. See e.g. https://bitcoincore.org/en/2024/07/03/disclose_already_asked_for/ - Load-balance between peers: don't overload peers; use all peers available. This is also useful for when we introduce per-peer orphan protection, since each peer will have limited slots. The approach taken in this PR is to think of each peer who announces an orphan as a potential "orphan resolution candidate." These candidates include: - the peer who sent us the orphan tx - any peers who announced the orphan prior to us downloading it - any peers who subsequently announce the orphan after we have started trying to resolve it For each orphan resolution candidate, we treat them as having "announced" all of the missing parents to us at the time of receipt of this orphan transaction (or at the time they announced the tx if they do so after we've already started tracking it as an orphan). We add the missing parents as entries to `m_txrequest`, incorporating the logic of typical txrequest processing, which means we prefer outbounds, try not to have duplicate requests in flight, don't overload peers, etc. ACKs for top commit: marcofleon: Code review ACK 86d7135e36efd39781cf4c969011df99f0cbb69d instagibbs: reACK 86d7135e36efd39781cf4c969011df99f0cbb69d dergoegge: Code review ACK 86d7135e36efd39781cf4c969011df99f0cbb69d mzumsande: ACK 86d7135e36efd39781cf4c969011df99f0cbb69d Tree-SHA512: 618d523b86e60c3ea039e88326d50db4e55e8e18309c6a20e8f2b10ed9e076f1de0315c335fd3b8abdabcc8b53cbceb66fb59147d05470ea25b83a2b4bd9c877
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/licenses/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 built for Windows, Linux, and macOS, and that unit/sanity tests are run automatically.
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.