Skip to content

splicing: Adds the features needed to enable collaborative splicing & resizing of active channels.#5675

Closed
ddustin wants to merge 819 commits into
ElementsProject:masterfrom
ddustin:ddustin/splice
Closed

splicing: Adds the features needed to enable collaborative splicing & resizing of active channels.#5675
ddustin wants to merge 819 commits into
ElementsProject:masterfrom
ddustin:ddustin/splice

Conversation

@ddustin
Copy link
Copy Markdown
Collaborator

@ddustin ddustin commented Oct 25, 2022 •
edited
Loading

Note this PR has been closed in favor of #6253

This PR is meant to add splicing to CoreLightning. Splicing enables the resizing of multiple channels in a single on-chain transaction, without any channels being "down" or closed during any part of the process. While enabling the resizing of multiple of your own channels -- splicing also gives your peers (and their peers, and their peers' peers, etc.) an opportunity to dynamically add channels as well.

Not only can participants add their own resizes, due to compatibility with @niftynei's dual funding feature, they can also add channel opens into the same batch. Eventually dual closing will allow all onchain lightning events to be batched into a single bitcoin transaction.

This will also, in time, enable wallets to implement "one balance" apps that allow users to send lightning & on-chain payments without needing to manage two "bitcoin balances" -- with the lowest fees possible.

The code implements splicing spec located here: lightning/bolts#863

My endless gratitude to @niftynei 🙏 who has helped an insane amount with planning, disagnosing, and literally writing parts of the code -- not sure I could have gotten this far without her. Thanks as well to @cdecker, @rustyrussell and everyone who helped me while working on this.

Here are the things I believe need to be done before the PR can be considered ready for a developer-only release

  • Refactor splice_init RPC to take a user's initial PSBT
  • Do byte ownership fee calculations
  • Enable signature ordering logic
  • Add splice commit sigs to inflight
  • Redo inflight process to cache a copy in channeld
  • Add BOLT messages with corresponding commit hashes
  • Change splice RPC to use channel_id instead of peer_id
  • Finish Collaborative transaction building #5287
  • Refactor this code to use Collaborative transaction building #5287
  • Refactor RPC to remove splice_finalized
  • Move wire updates to experimental patches
  • Add #if EXPERIMENTAL && DEVELOPER flags around code
  • Diagnose why the committed_splice_count check fails in handle_peer_commitsig
  • Update channel balance on splice_locked & save to DB
  • Load correct channel balance post splice_lock after restart
  • Test splicing a post-spliced channel
  • Check for TODO items in code
  • Correct balance checks for the l2 code path lisa gist. See check_balances
  • Reconnect logic

@vnprc vnprc mentioned this pull request Oct 26, 2022
Closed
niftynei
niftynei requested changes Nov 3, 2022
View reviewed changes
Copy link
Copy Markdown
Collaborator

@niftynei niftynei left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

biggest PR ever, but looking like a great splice_start.

Reviewed in-person w/ @ddustin, really really nice work!

Comment thread lightningd/peer_htlcs.c Outdated
Comment thread common/psbt_internal.c Outdated
Comment thread hsmd/hsmd_wire.csv
Comment thread hsmd/libhsmd.c Outdated
Comment thread lightningd/channel_control.c Outdated
Comment thread lightningd/channel_control.c Outdated
Comment thread tests/test_splicing.py Outdated
Comment thread tests/test_splicing.py Outdated
Comment thread tests/test_splicing.py Outdated
Comment thread tests/test_splicing.py Outdated
@niftynei
Copy link
Copy Markdown
Collaborator

niftynei commented Nov 3, 2022

Splice to the moon! 🚀 🌔

@ddustin ddustin force-pushed the ddustin/splice branch 2 times, most recently from 9ee496a to 8b0713a Compare November 23, 2022 13:10
@ddustin
Copy link
Copy Markdown
Collaborator Author

ddustin commented Dec 30, 2022

Forcing locktime to 0 until a spec conversation can happen: https://github.com/lightning/bolts/pull/863/files#r1059493624

@ddustin ddustin force-pushed the ddustin/splice branch 2 times, most recently from 81c2ab5 to e1e0fb6 Compare January 10, 2023 18:04
@ddustin ddustin mentioned this pull request Jan 18, 2023
Open
71 tasks
@ddustin
Copy link
Copy Markdown
Collaborator Author

ddustin commented Jan 18, 2023

Forcing locktime to 0 until a spec conversation can happen: https://github.com/lightning/bolts/pull/863/files#r1059493624

Spec talk was to allow all locktimes in the spec and implementations can restrict which they'll accept as they decide (ie not too far in the future).

@piqjen-1xofFi-sikxyh
Copy link
Copy Markdown

piqjen-1xofFi-sikxyh commented Jan 22, 2023

🚀

@ddustin ddustin marked this pull request as ready for review March 6, 2023 00:18
@ddustin ddustin requested a review from cdecker as a code owner March 6, 2023 00:18
@ddustin ddustin force-pushed the ddustin/splice branch 15 times, most recently from 625e737 to d1aceb3 Compare March 6, 2023 14:28
rustyrussell and others added 23 commits May 11, 2023 20:20
@rustyrussell @ddustin
doc: document that urgent doesn't use the 2-block estimate, but the 6…
5c3984a 
…-block.

Turns out this was accidentally changed for v0.10.1 in
d8e6889 where we made fee levels less
aggressive.

Oops.  I guess we can fix the docs.  And we now have "2blocks" if you
want it really fast!

Closes: ElementsProject#6129
Changelog-Fixed: JSON-RPC: `feerates` document correctly that urgent means 6 blocks (not 2), and give better feerate examples.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
@ddustin
Mac: Update Makefile to work on Mac zsh
b721484 
Using the -n flag on echo is non-standard for zsh. printf ‘%s’ accomplishes the equivilent thing.

Changelog-Added: Small fix for Mac OS building
@ddustin
hsmd: Add sign splice command
b60e9ee 
Changelog-None
@ddustin
psbt: routine for lining up sigantures in a witness stack
cc711cc 
Changelog-None
@ddustin
splicing: Add channel state AWAITING_SPLICE
ffd98bb 
Update gossip routiens and various other hecks on the channel state to consider AWAITING_SPLICE to be routable and treated similar to CHANNELD_NORMAL.

Small updates to psbt interface

Changelog-None
@ddustin
psbt: Fix psbt linseraize_input bug
1ae78bc 
Some fields weren’t intitialized causing complex crashes elsewhere.

Changelog-None
@ddustin
splicing: Register feature bit
fd33d89 
Changelog-None
@ddustin
splicing: add flexible version of channel_txs
aa3025a 
Changelog-None
@ddustin
splicing: add DB details for splice HTLCs
e783bad 
Changelog-None
@ddustin
channeld: Code to implement splicing
7be880a 
Update the lightningd <-> channeld interface with lots of new commands to needed to facilitate spicing.

Implement the channeld splicing protocol leveraging the interactivetx protocol.

Implement lightningd’s channel_control to support channeld in its splicing efforts.

Changelog-Added: Added the features to enable splicing & resizing of active channels.
@niftynei @ddustin
contrib/startup: ignore db-updates; fix typo
e615512
@niftynei @ddustin
splice: start with starting balances
32ad28d 
# Conflicts:
#	channeld/channeld.c
@ddustin
fixup! channeld: Code to implement splicing
02eb660
@ddustin
fixup! channeld: Code to implement splicing
ff450c8 
Switches implementation over to a signed relative amount instead of absolute splice result
@ddustin
fixup! channeld: Code to implement splicing
13e8fd9 
Make HTLC balance enforcement aware of pending slice-out’s
@ddustin
fixup! channeld: Code to implement splicing
7c62ea0 
Handle REMOTE vs LOCAL on view correctly
@ddustin
fixup! channeld: Code to implement splicing
5296720 
Fixing small balance typos
@ddustin
fixup! channeld: Code to implement splicing
fe74192 
Implement channel reestablish for splicing
@ddustin
fixup! channeld: Code to implement splicing
659c559 
Fix shadow variable problem
@niftynei @ddustin
inflights: use ctx for making new ones
1acc9ba 
Also convert everything to an array thingy
@niftynei @ddustin
fixup! fixup! channeld: Code to implement splicing
ea31c8f
@niftynei @ddustin
fixup! inflights: use ctx for making new ones
8e31fc2
@niftynei @ddustin
fixup! channeld: Code to implement splicing
e49a6f7
@ddustin ddustin closed this May 12, 2023
@ddustin ddustin deleted the ddustin/splice branch May 12, 2023 01:11
@ddustin
Copy link
Copy Markdown
Collaborator Author

ddustin commented May 12, 2023

Github inadvertently auto-closed this PR. It appears I don't have repo permissions to re-open it.

Could someone with admin privileges reopen it for me?

@ddustin ddustin mentioned this pull request May 12, 2023
Merged
19 tasks
@ddustin
Copy link
Copy Markdown
Collaborator Author

ddustin commented May 12, 2023

Due to github's "force-close" I had to move this over to a new PR: #6253

@btsea btsea mentioned this pull request Sep 8, 2023
Closed
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@niftynei niftynei niftynei requested changes

@cdecker cdecker Awaiting requested review from cdecker cdecker is a code owner

@ZmnSCPxj ZmnSCPxj Awaiting requested review from ZmnSCPxj

Assignees

No one assigned

Labels

None yet

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.