5a6d00c6de
Currently we have no rotation of outbound peers. If an outbound peer stops serving us blocks, or is on a consensus-incompatible chain with less work than our tip (but otherwise valid headers), then we will never disconnect that peer, even though that peer is using one of our 8 outbound connection slots. Because we rely on our outbound peers to find an honest node in order to reach consensus, allowing an incompatible peer to occupy one of those slots is undesirable, particularly if it is possible for all such slots to be occupied by such peers. Protect against this by always checking to see if a peer's best known block has less work than our tip, and if so, set a 20 minute timeout -- if the peer is still not known to have caught up to a chain with as much work as ours after 20 minutes, then send a single getheaders message, wait 2 more minutes, and if a better header hasn't been received by then, disconnect that peer. Note: - we do not require that our peer sync to the same tip as ours, just an equal or greater work tip. (Doing otherwise would risk partitioning the network in the event of a chain split, and is also unnecessary.) - we pick 4 of our outbound peers and do not subject them to this logic, to be more conservative. We don't wish to permit temporary network issues (or an attacker) to excessively disrupt network topology. |
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| .github | ||
| .tx | ||
| build-aux/m4 | ||
| contrib | ||
| depends | ||
| doc | ||
| share | ||
| src | ||
| test | ||
| .gitattributes | ||
| .gitignore | ||
| .travis.yml | ||
| autogen.sh | ||
| configure.ac | ||
| CONTRIBUTING.md | ||
| COPYING | ||
| INSTALL.md | ||
| libbitcoinconsensus.pc.in | ||
| Makefile.am | ||
| README.md | ||
Bitcoin Core integration/staging tree
What is Bitcoin?
Bitcoin is an experimental digital currency that enables instant payments to anyone, anywhere in the world. Bitcoin uses peer-to-peer technology to operate with no central authority: managing transactions and issuing money are carried out collectively by the network. Bitcoin Core is the name of open source software which enables the use of this currency.
For more information, as well as an immediately useable, binary version of the Bitcoin Core software, see https://bitcoin.org/en/download, or read the original whitepaper.
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 and tested, but is not guaranteed to be
completely stable. Tags are created
regularly to indicate new official, stable release versions of Bitcoin Core.
The contribution workflow is described in CONTRIBUTING.md.
The developer mailing list should be used to discuss complicated or controversial changes before working on a patch set.
Developer IRC can be found on Freenode at #bitcoin-core-dev.
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 in configure) with: make check. 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, that are run automatically on the build server.
These tests can be run (if the test dependencies are installed) with: test/functional/test_runner.py
The Travis CI system makes sure that every pull request is built for Windows, Linux, and OS X, 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.
Translators should also subscribe to the mailing list.