mirrors/rust-lightning
1
0
Fork 0
mirror of https://github.com/lightningdevkit/rust-lightning.git synced 2025-02-25 07:17:40 +01:00
Code Issues Projects Releases Packages Wiki Activity

Define a crate-public constant for max fake SCID in blocks offset

Browse source
This commit is contained in:
Matt Corallo 2022-05-13 18:30:12 +00:00
parent 585493a3e1
commit 168b3a51ae
1 changed files with 5 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
lightning/src/util/scid_utils.rs
View file

@ -79,6 +79,10 @@ pub(crate) mod fake_scid {
const MAX_NAMESPACES: u8 = 8; // We allocate 3 bits for the namespace identifier.
const NAMESPACE_ID_BITMASK: u8 = 0b111;
const BLOCKS_PER_MONTH: u32 = 144 /* blocks per day */ * 30 /* days per month */;
pub(crate) const MAX_SCID_BLOCKS_FROM_NOW: u32 = BLOCKS_PER_MONTH;
/// Fake scids are divided into namespaces, with each namespace having its own identifier between
/// [0..7]. This allows us to identify what namespace a fake scid corresponds to upon HTLC
/// receipt, and handle the HTLC accordingly. The namespace identifier is encrypted when encoded
@ -100,7 +104,6 @@ pub(crate) mod fake_scid {
// Ensure we haven't created a namespace that doesn't fit into the 3 bits we've allocated for
// namespaces.
assert!((*self as u8) < MAX_NAMESPACES);
const BLOCKS_PER_MONTH: u32 = 144 /* blocks per day */ * 30 /* days per month */;
let rand_bytes = keys_manager.get_secure_random_bytes();
let segwit_activation_height = segwit_activation_height(genesis_hash);
@ -109,7 +112,7 @@ pub(crate) mod fake_scid {
// We want to ensure that this fake channel won't conflict with any transactions we haven't
// seen yet, in case `highest_seen_blockheight` is updated before we get full information
// about transactions confirmed in the given block.
blocks_since_segwit_activation = blocks_since_segwit_activation.saturating_sub(BLOCKS_PER_MONTH);
blocks_since_segwit_activation = blocks_since_segwit_activation.saturating_sub(MAX_SCID_BLOCKS_FROM_NOW);
let rand_for_height = u32::from_be_bytes(rand_bytes[..4].try_into().unwrap());
let fake_scid_height = segwit_activation_height + rand_for_height % (blocks_since_segwit_activation + 1);