Exchange node capabilities when performing network handshake by pwojcikdev · Pull Request #5043 · nanocurrency/nano-node

pwojcikdev · 2026-03-17T17:53:46Z

This introduces a V3 node ID handshake that allows nodes to advertise optional capabilities to their peers.

Motivation

This is building toward a network of specialized nodes: nodes that opt into providing additional services beyond standard consensus participation. For example, a node with topo_index capability can serve topologically ordered block data, enabling dramatically faster bootstrapping for peers. A node with vote_storage can relay historical vote data, helping peers that fall behind to catch up quickly without re-requesting votes from representatives.

By advertising these capabilities during the handshake, peers can discover which nodes offer which services and route requests accordingly.

gr0vity-dev-bot · 2026-03-17T19:37:26Z

Test Results for Commit `b0786c2`

Pull Request 5043: Results
Overall Status: ❌

Test Case Results

✅ 5n4pr_conf_10k_bintree: PASS (Duration: 115s)
✅ 5n4pr_conf_10k_change: PASS (Duration: 137s)
✅ 5n4pr_conf_change_dependant: PASS (Duration: 150s)
✅ 5n4pr_conf_change_independant: PASS (Duration: 135s)
✅ 5n4pr_conf_send_dependant: PASS (Duration: 144s)
✅ 5n4pr_conf_send_independant: PASS (Duration: 132s)
✅ 5n4pr_rocks_10k_bintree: PASS (Duration: 125s)
❌ 5n4pr_rocks_10k_change: FAIL (Duration: 284s)
Log

Last updated: 2026-03-19 16:05:08 UTC

Copilot

Pull request overview

This PR adds a v3 node-id handshake extension to advertise optional node capability flags to peers during TCP handshakes, enabling discovery/routing toward specialized service providers.

Changes:

Introduces handshake_version and a v3 node_id_handshake response payload carrying capability flags.
Propagates capability flags from handshake responses into tcp_channel state for later use.
Adds enum_flags and node_capabilities utilities plus tests covering v3 serialization/signing and flag exchange.

Reviewed changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
nano/node/transport/tcp_server.hpp	Updates handshake response API and realtime transition to carry capability flags.
nano/node/transport/tcp_server.cpp	Passes negotiated handshake version and stores peer capability flags on channel creation.
nano/node/transport/tcp_channels.hpp	Extends `create()` to accept optional capability flags.
nano/node/transport/tcp_channels.cpp	Persists capability flags onto newly created channels.
nano/node/transport/channel.hpp	Adds per-channel storage/accessors for peer capability flags.
nano/node/nodeconfig.hpp	Adds testing-only capability override flag set.
nano/node/node.hpp	Exposes `node::get_capabilities()` API.
nano/node/node.cpp	Implements `get_capabilities()` (currently override-only, TODO for real config/state).
nano/node/network.hpp	Updates handshake response preparation to use `handshake_version`.
nano/node/network.cpp	Builds v2/v3 handshake responses; v3 includes capabilities.
nano/messages/node_id_handshake.hpp	Adds handshake v3 payload + `handshake_version` and replaces v2 optional with a variant `ext`.
nano/messages/node_id_handshake.cpp	Implements v3 flagging, (de)serialization, signing preimage, and accessors for genesis/flags.
nano/lib/utility.hpp	Adds `nano::overloaded` helper for `std::visit`.
nano/lib/node_capabilities.hpp	Defines capability enum + flags type.
nano/lib/node_capabilities.cpp	Implements capability string conversion and instantiates enum_flags formatting helpers.
nano/lib/enum_flags_templ.hpp	Adds streaming/to_string templates for `enum_flags`.
nano/lib/enum_flags.hpp	Adds `enum_flags` bitfield wrapper.
nano/lib/CMakeLists.txt	Registers node capabilities sources in the lib target.
nano/core_test/tcp_server.cpp	Adds integration test validating capability flag exchange via v3 handshake.
nano/core_test/message.cpp	Updates handshake tests and adds v3 serialization/signature tests.
nano/core_test/enums.cpp	Adds unit tests for `enum_flags` behavior and formatting.

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nano/messages/node_id_handshake.cpp

nano/lib/enum_flags_templ.hpp

Copilot

Pull request overview

Adds a V3 node ID handshake extension so peers can exchange advertised node capabilities during the TCP handshake, enabling discovery of specialized service providers on the network.

Changes:

Introduces handshake_version and a V3 handshake response payload carrying node_capabilities_flags.
Propagates negotiated capability flags into transport::channel/tcp_channel via tcp_channels::create(...).
Adds a new enum_flags<> utility plus tests for V3 handshake serialization/signatures and end-to-end flag exchange.

Reviewed changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
nano/node/transport/tcp_server.hpp	Plumbs handshake version + capability flags through realtime upgrade path.
nano/node/transport/tcp_server.cpp	Uses `handshake_version` for response generation; stores peer flags on channel creation.
nano/node/transport/tcp_channels.hpp	Extends channel creation API to accept capability flags (defaulted).
nano/node/transport/tcp_channels.cpp	Sets capability flags on newly created TCP channels.
nano/node/transport/channel.hpp	Adds capability flags storage/accessors on channels.
nano/node/nodeconfig.hpp	Adds test-only capability override to `node_flags`.
nano/node/node.hpp	Exposes `node::get_capabilities()` for handshake response population.
nano/node/node.cpp	Implements `get_capabilities()` (currently override-or-empty, TODO for real config/state).
nano/node/network.hpp	Updates handshake response preparation API to accept handshake version.
nano/node/network.cpp	Generates V2/V3 response payloads; verifies genesis via new response accessor.
nano/messages/node_id_handshake.hpp	Adds `handshake_version`, V3 payload, and `variant`-based extension storage + accessors.
nano/messages/node_id_handshake.cpp	Implements V3 serialization/deserialization/signing and header version flag handling.
nano/lib/utility.hpp	Adds `nano::overloaded` helper for `std::visit` multi-lambda usage.
nano/lib/node_capabilities.hpp	Introduces node capability enum + flags alias.
nano/lib/node_capabilities.cpp	Implements capability string conversion and flag printing/to_string instantiations.
nano/lib/enum_flags_templ.hpp	Adds templated `operator<<`/`to_string` for `enum_flags<>`.
nano/lib/enum_flags.hpp	Adds `enum_flags<>` type-safe bitflag wrapper.
nano/lib/CMakeLists.txt	Adds new node capabilities sources to `nano_lib`.
nano/core_test/tcp_server.cpp	Updates handshake tests and adds e2e test for exchanging capability flags.
nano/core_test/message.cpp	Updates handshake response tests; adds V3 serialization + signature tests.
nano/core_test/enums.cpp	Adds unit tests for `enum_flags<>` formatting/behavior.

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nano/messages/node_id_handshake.hpp

nano/lib/CMakeLists.txt

Introduce `enum_flags<E>` template providing a std::bitset-like API for power-of-2 flag enums with set/reset/test operations, bitwise operators, and magic_enum-based string conversion.

Extend the handshake protocol to advertise node capabilities as a bitfield in the response payload. Replace the v2 optional with a variant over v1/v2/v3 payloads and propagate capabilities to the channel on connection.

Copilot

Pull request overview

This PR introduces a V3 node_id_handshake format that allows peers to exchange and persist optional node capability flags during the TCP handshake, enabling future request routing to specialized nodes.

Changes:

Added handshake V3 support using a versioned response_payload::ext (std::variant) carrying capability flags.
Plumbed advertised capability flags from handshake response into transport::channel via tcp_channels::create(...).
Introduced enum_flags<> + node_capabilities definitions and added unit tests for V3 serialization/signature and flag exchange.

Reviewed changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
nano/node/transport/tcp_server.hpp	Updates handshake response API to use `handshake_version`; plumbs capabilities into realtime channel creation.
nano/node/transport/tcp_server.cpp	Uses negotiated handshake version; passes received capability flags into channel creation.
nano/node/transport/tcp_channels.hpp	Extends `create(...)` to accept capability flags (default `{}`).
nano/node/transport/tcp_channels.cpp	Stores capability flags on newly created channels.
nano/node/transport/channel.hpp	Adds thread-safe getters/setters and storage for per-peer capability flags.
nano/node/nodeconfig.hpp	Adds `capabilities_override` test hook for forcing advertised capabilities.
nano/node/node.hpp	Adds `node::get_capabilities()` API.
nano/node/node.cpp	Implements `get_capabilities()` (currently override-or-empty with TODO).
nano/node/network.hpp	Updates handshake response preparation to take `handshake_version`.
nano/node/network.cpp	Builds V2/V3 handshake responses; V3 includes capabilities in the signed payload.
nano/messages/node_id_handshake.hpp	Adds `handshake_version`, V3 payload, variant-based extensions, and accessors for genesis/flags.
nano/messages/node_id_handshake.cpp	Implements version selection, V3 (de)serialization, and signing/validation over the versioned payload.
nano/lib/utility.hpp	Adds `nano::overloaded` helper for `std::visit`.
nano/lib/node_capabilities.hpp	Defines capability bits and `node_capabilities_flags`.
nano/lib/node_capabilities.cpp	Implements `to_string(node_capabilities)` and instantiates enum_flags streaming/to_string for capabilities.
nano/lib/enum_flags.hpp	Introduces type-safe bitflag wrapper used by capabilities.
nano/lib/enum_flags_templ.hpp	Adds streaming/to_string implementations for `enum_flags<>`.
nano/lib/CMakeLists.txt	Wires new lib sources/headers into the build.
nano/core_test/tcp_server.cpp	Adds integration test ensuring V3 handshake exchanges and stores capability flags.
nano/core_test/message.cpp	Adds V3 serialization and signature tests; updates V2 tests for `ext` variant.
nano/core_test/enums.cpp	Adds unit tests for `enum_flags<>` behavior and formatting.

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nano/lib/enum_flags.hpp

+	{
+		static_assert (std::is_standard_layout_v<enum_flags>, "Standard layout required for safe underlying type punning");
+		static_assert (std::is_trivially_copyable_v<enum_flags>, "Trivially copyable required for safe underlying type punning");
+		static_assert (sizeof (enum_flags) == sizeof (underlying_t), "Size of enum_flags must be the same as underlying type");
+	}


pwojcikdev force-pushed the handshake-node-capabilities-2 branch 2 times, most recently from 9057d2b to 117001f Compare March 17, 2026 18:06

pwojcikdev force-pushed the handshake-node-capabilities-2 branch from 117001f to 2decca4 Compare March 18, 2026 22:58

pwojcikdev requested a review from Copilot March 19, 2026 00:17

Copilot AI reviewed Mar 19, 2026

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nano/lib/enum_flags_templ.hpp Outdated Show resolved Hide resolved

pwojcikdev force-pushed the handshake-node-capabilities-2 branch 3 times, most recently from 6160f54 to bf32284 Compare March 19, 2026 12:45

pwojcikdev requested a review from Copilot March 19, 2026 12:52

Copilot AI reviewed Mar 19, 2026

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pwojcikdev added 2 commits March 19, 2026 15:18

Add enum_flags bitfield wrapper

8561675

Introduce `enum_flags<E>` template providing a std::bitset-like API for power-of-2 flag enums with set/reset/test operations, bitwise operators, and magic_enum-based string conversion.

Add V3 handshake with node capabilities field

b0786c2

Extend the handshake protocol to advertise node capabilities as a bitfield in the response payload. Replace the v2 optional with a variant over v1/v2/v3 payloads and propagate capabilities to the channel on connection.

pwojcikdev force-pushed the handshake-node-capabilities-2 branch from bf32284 to b0786c2 Compare March 19, 2026 14:18

pwojcikdev requested a review from Copilot March 19, 2026 17:04

Copilot started reviewing on behalf of pwojcikdev March 19, 2026 17:04 View session

Copilot AI reviewed Mar 19, 2026

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pwojcikdev merged commit 6f405e0 into nanocurrency:develop Mar 19, 2026
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Exchange node capabilities when performing network handshake#5043

Exchange node capabilities when performing network handshake#5043
pwojcikdev merged 2 commits intonanocurrency:developfrom
pwojcikdev:handshake-node-capabilities-2

pwojcikdev commented Mar 17, 2026

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pwojcikdev commented Mar 17, 2026

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gr0vity-dev-bot commented Mar 17, 2026 •

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Test Results for Commit `b0786c2`