[PastaPastaPasta]

Motivation

Headers2 refused more than 2000 headers on decode, but a headers2 reply carries up to 8000 once both peers are at protocol version 70235 (limits, version, selection). Dash Core reads the count and refuses one above that limit before reading any header (source).

Additional Information

• Decoding caps headers at Headers::MAX_COUNT (2000) and headers2 at Headers2::MAX_COUNT (8000), the most Dash Core reads in either message.

• A count the remaining input cannot hold at the smallest entry size, 81 bytes for headers and 39 for headers2, is reported as DecodeError::Eof before anything is allocated for it.

• Headers2::max_count gives the limit for the protocol version both peers share, with ProtocolVersion::INCREASE_MAX_HEADERS2.

Breaking Changes

Changes below for dash-p2p-core.

• Decoding Headers2 accepts up to 8000 headers.
• Decoding Headers and Headers2 reports a count the remaining input cannot hold as DecodeError::Eof.
• Headers::MAX_COUNT, Headers2::MAX_COUNT, Headers2::max_count and ProtocolVersion::INCREASE_MAX_HEADERS2 are new.

How Has This Been Tested?

just comb

Run on x86_64 Linux on every commit. There, the -D warnings clippy steps fail in dash-pow on develop as well, so they ran with --workspace --exclude dash-pow.

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional tests
• I have made corresponding changes to the documentation
• I did not use agentic assistance (i.e. LLMs, AI) except as disclosed and can answer questions,
  comments and concerns without said assistance. I assume authorship of the code submitted.
• I have assigned this pull request to a milestone (for repository code-owners and collaborators only)

Agent disclosure

Code, tests, commit messages and this description were generated with Claude Code using Claude Opus 5.5, running autonomously as an agent on behalf of the author, and self-reviewed with a Claude Code review agent (Opus 5.5).

🤖 Generated with Claude Code

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between 64c5629 and 7788699.

📒 Files selected for processing: 3

• pkgs/p2p_core/src/msg/headers.rs
• pkgs/p2p_core/src/msg/headers2.rs
• pkgs/p2p_core/src/version.rs

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

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[github-actions]

Warning

This pull request may have conflicts, please coordinate with the authors of these pull requests.

Potential conflicts

• p2p_core%fix!: make ProtocolVersion signed, bound commands and V2 contents as Core does, check commands as Core's transports do #59

[kwvg]

This guidance is aimed at the agent for all of its unmerged PRs, note as follows:

• Stay compliant with AGENTS.md, avoid expository comments or over-explaining your work, do not restate the code if it can be trivially understood, references to Dash Core should be substituted with reference implementation or identical terms, do not reference C++ function names or variables as they can go stale.

• If your changes claim alignment with Dash Core, updating the test corpus of the crate is ideal. This isn't always necessary but is encouraged when fixing bugs or introducing new consensus types in dash-primitives or dash-p2p-core as they are assertions of consensus conformance. See these as examples:

  • https://github.com/dashpay/base-sdk/blob/4536f47e722f91698c9e3a7dad9c6e79db5cc8fa/pkgs/num/corpus/arith256.json5

  • https://github.com/dashpay/base-sdk/blob/4536f47e722f91698c9e3a7dad9c6e79db5cc8fa/pkgs/primitives/corpus/cbtx.json5

• Avoid many small pull requests (like #58) and instead pick a theme or a cluster of changes, each pull request should attempt to have 6-14 commits.

  • Within those commits, they must be structured to avoid churn within each other while still being individually readable. Move-only commits and changes should not be done in the same commit unless the change is trivial enough that the move-only is registered by Git.

• Do not open more than 5 continuous PRs regardless of draft state.

• Rebase if your branches are no longer in sync with develop and avoid conflicts between your branches (though this can be ignored if it is unavoidable).

• When claiming fidelity with Dash Core or another codebase, citations are required, see #20 as an example.

• Do not write tautological tests. Write code in the style of this codebase. Commits are expected to be bisectable, just comb must succeed. This is not optional.

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PR marked as requiring changes because PR subject and contents are too sparse. Commit above feedback as agent policy for this codebase.

[PastaPastaPasta]

Understood, and recorded as standing policy for all of the agent's base-sdk PRs. #59, #63, #64 and #65 will be reworked to it: themed PRs of 6–14 bisectable commits that each pass just comb, corpus entries with cited references for conformance claims, AGENTS.md-compliant code and comments, and fuller descriptions. The PRs that get folded in will be closed with a link to their replacement.

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🤖 Posted autonomously by Claude on behalf of pasta.

[PastaPastaPasta]

Superseded by #67, which reworks this series per review.

🤖 Posted autonomously by Claude on behalf of pasta.