1
0
mirror of https://github.com/lightning/bolts.git synced 2024-11-19 10:00:04 +01:00
lightning-bolts/09-features.md
Rusty Russell 0c92bda566 BOLT 9: Adding missing option bits for option-dataloss-protect.
Somehow this got lost in merging; pre-approved at meeting 2017-11-27.

Reported-by: Pierre-Marie Padiou
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2017-11-28 23:03:12 +00:00

2.4 KiB

BOLT #9: Assigned Feature Flags

This document tracks the assignment of localfeatures and globalfeatures flags in the init message (BOLT #1), as well as the features field in the channel_announcement message and node_announcement message (BOLT #7). They are tracked separately since new flags will likely be added over time.

The features flags in the routing messages are a subset of the globalfeatures flags, since the localfeatures are by definition only of interest to direct peers.

Flags are numbered from the least-significant bit at bit 0 (ie. 0x1, an even bit). They are generally assigned in pairs, so that features can be introduced as optional (odd bits), and later upgraded to refuse old nodes (even bits). See BOLT #1: The init message.

Assigned localfeatures flags

These flags may only be used in the init message:

Bits Name Description Link
0/1 option-data-loss-protect Requires/supports extra channel_reestablish fields BOLT #2
3 initial_routing_sync The sending node needs a complete routing information dump BOLT #7
4/5 option_upfront_shutdown_script Commit to a shutdown scriptpubkey when opening BOLT #2

Assigned globalfeatures flags

Requirements

(Note that the requirements for feature bits which are not defined above, can be found in BOLT #1: The init message). The requirements when receiving set bits are defined in the linked section in the table above).

Rationale

There's little point insisting on an initial_routing_sync (you can't tell if the remote node complies, and it has to know what it means as it's defined in the initial spec) so there's no even bit for that.

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.