Update the Database section to reference both PRs that prepare the
graph DB for gossip v2 support:
- PR 10339: node handling
- PR 10379: channel handling (this PR)
This commit fixes a backwards compatibility issue that prevented nodes
from upgrading from v0.19.x to v0.20.x.
In v0.19.x, channel edge features were serialized as raw feature bytes
without a length prefix. In v0.20.x (commit 2f2845dfc), the serialization
changed to use Features.Encode() which adds a 2-byte big-endian length
prefix before the feature bits. The deserialization code was updated to
use Features.Decode() which expects this length prefix.
When v0.20.x reads a database created by v0.19.x, Decode() tries to read
a length prefix that doesn't exist, causing an EOF error:
unable to decode features: EOF
The fix adds a deserializeChanEdgeFeatures() helper that detects which
format is being read and decodes accordingly:
- New format (v0.20+): First 2 bytes encode the length of the remaining
bytes. Detected when uint16(bytes[0:2]) == len(bytes)-2.
- Legacy format (pre-v0.20): Raw feature bits without length prefix.
Uses DecodeBase256 with the known length.
The format detection is safe because in the legacy format, the first byte
always has at least one bit set (the serialization uses minimum bytes),
so the first two bytes can never encode a value equal to len-2.
Fixes#10528.
In this commit, we add validation for channel updates and node
announcements to ensure that we reject gossip messages with zero
timestamps at the discovery layer.
From BOLT 7:
"MUST set timestamp to greater than 0, AND to greater than any
previously-sent channel_update for this short_channel_id."
This validation is performed in the gossip handlers (handleNodeAnnouncement
and handleChanUpdate) rather than at the wire protocol level. This approach
ensures we can still decode messages from disk or embedded in onion errors
while rejecting invalid gossip from peers.
Remote peers sending zero-timestamp gossip will have their ban score
incremented.
In the previous iteration with endorsement
signaling, the recommendation was for the sender to
set it to 1 and that could have had privacy concerns
when first deploying given that the default was to
downgrade the signal to 0. In the latest proposal
the recommended default for both sending and
forwarding nodes is to set `accountable` to 0.
As a result, the dates have been removed given
that there are no privacy risks associated
with relaying the signal with zero values.
Document the new MuSig2RegisterCombinedNonce and MuSig2GetCombinedNonce RPC
methods in the v0.21.0 release notes. These methods enable coordinator-based
signing patterns as an alternative to the standard MuSig2RegisterNonces
workflow.
