litecoin

History

MarcoFalke 384e090f93 Merge #19509 : Per-Peer Message Capture `bff7c66e67` Add documentation to contrib folder (Troy Giorshev) `381f77be85` Add Message Capture Test (Troy Giorshev) `e4f378a505` Add capture parser (Troy Giorshev) `4d1a582549` Call CaptureMessage at appropriate locations (Troy Giorshev) `f2a77ff97b` Add CaptureMessage (Troy Giorshev) `dbf779d5de` Clean PushMessage and ProcessMessages (Troy Giorshev) Pull request description: This PR introduces per-peer message capture into Bitcoin Core. 📓 ## Purpose The purpose and scope of this feature is intentionally limited. It answers a question anyone new to Bitcoin's P2P protocol has had: "Can I see what messages my node is sending and receiving?". ## Functionality When a new debug-only command line argument `capturemessages` is set, any message that the node receives or sends is captured. The capture occurs in the MessageHandler thread. When receiving a message, it is captured as soon as the MessageHandler thread takes the message off of the vProcessMsg queue. When sending, the message is captured just before the message is pushed onto the vSendMsg queue. The message capture is as minimal as possible to reduce the performance impact on the node. Messages are captured to a new `message_capture` folder in the datadir. Each node has their own subfolder named with their IP address and port. Inside, received and sent messages are captured into two binary files, msgs_recv.dat and msgs_sent.dat, like so: ``` message_capture/203.0.113.7:56072/msgs_recv.dat message_capture/203.0.113.7:56072/msgs_sent.dat ``` Because the messages are raw binary dumps, included in this PR is a Python parsing tool to convert the binary files into human-readable JSON. This script has been placed on its own and out of the way in the new `contrib/message-capture` folder. Its usage is simple and easily discovered by the autogenerated `-h` option. ## Future Maintenance I sympathize greatly with anyone who says "the best code is no code". The future maintenance of this feature will be minimal. The logic to deserialize the payload of the p2p messages exists in our testing framework. As long as our testing framework works, so will this tool. Additionally, I hope that the simplicity of this tool will mean that it gets used frequently, so that problems will be discovered and solved when they are small. ## FAQ "Why not just use Wireshark" Yes, Wireshark has the ability to filter and decode Bitcoin messages. However, the purpose of the message capture added in this PR is to assist with debugging, primarily for new developers looking to improve their knowledge of the Bitcoin Protocol. This drives the design in a different direction than Wireshark, in two different ways. First, this tool must be convenient and simple to use. Using an external tool, like Wireshark, requires setup and interpretation of the results. To a new user who doesn't necessarily know what to expect, this is unnecessary difficulty. This tool, on the other hand, "just works". Turn on the command line flag, run your node, run the script, read the JSON. Second, because this tool is being used for debugging, we want it to be as close to the true behavior of the node as possible. A lot can happen in the SocketHandler thread that would be missed by Wireshark. Additionally, if we are to use Wireshark, we are at the mercy of whoever it maintaining the protocol in Wireshark, both as to it being accurate and recent. As can be seen by the many previous attempts to include Bitcoin in Wireshark (google "bitcoin dissector") this is easier said than done. Lastly, I truly believe that this tool will be used significantly more by being included in the codebase. It's just that much more discoverable. ACKs for top commit: MarcoFalke: re-ACK `bff7c66e67` only some minor changes: 👚 jnewbery: utACK `bff7c66e67` theStack: re-ACK `bff7c66e67` Tree-SHA512: e59e3160422269221f70f98720b47842775781c247c064071d546c24fa7a35a0e5534e8baa4b4591a750d7eb16de6b4ecf54cbee6d193b261f4f104e28c15f47		4 years ago
..
debian	doc: Update license year range to 2021	4 years ago
devtools	doc: Add manual page generation for bitcoin-util	4 years ago
gitian-descriptors	gitian-linux: Extend noexec-stack workaround to powerpc	4 years ago
gitian-keys	gitian-keys: Add signer aliases, some historical keys	4 years ago
guix	guix: Fix typo	4 years ago
init	doc: Fix systemd spelling and link to doc/init.md	4 years ago
linearize	…
macdeploy	gitian: use signapple to create the MacOS code signature	4 years ago
message-capture	Add documentation to contrib folder	4 years ago
qos	…
seeds	Merge #20288 : script, doc: contrib/seeds updates	4 years ago
signet	contrib/signet: Document miner script in README.md	4 years ago
testgen	scripted-diff: Bump copyright headers	4 years ago
verify-commits	…
verifybinaries	contrib: remove verify.sh	4 years ago
windeploy	…
zmq	scripted-diff: Bump copyright headers	4 years ago
README.md	…
bitcoin-cli.bash-completion	…
bitcoin-qt.pro	…
bitcoin-tx.bash-completion	…
bitcoind.bash-completion	…
filter-lcov.py	scripted-diff: Bump copyright headers	4 years ago
gitian-build.py	Fix docker args conditional	4 years ago
install_db4.sh	contrib: embed C++11 patch in install_db4.sh	4 years ago
valgrind.supp	…

README.md

Repository Tools

Developer tools

Specific tools for developers working on this repository. Additional tools, including the github-merge.py script, are available in the maintainer-tools repository.

Verify-Commits

Tool to verify that every merge commit was signed by a developer using the github-merge.py script.

Linearize

Construct a linear, no-fork, best version of the blockchain.

A Linux bash script that will set up traffic control (tc) to limit the outgoing bandwidth for connections to the Bitcoin network. This means one can have an always-on bitcoind instance running, and another local bitcoind/bitcoin-qt instance which connects to this node and receives blocks from it.

Seeds

Utility to generate the pnSeed[] array that is compiled into the client.

Build Tools and Keys

Packaging

The Debian subfolder contains the copyright file.

All other packaging related files can be found in the bitcoin-core/packaging repository.

Test and Verify Tools

TestGen

Utilities to generate test vectors for the data-driven Bitcoin tests.

Verify Binaries

This script attempts to download and verify the signature file SHA256SUMS.asc from bitcoin.org.