Update next_funding spec requirements#4098

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Merged
TheBlueMatt merged 2 commits into from
Sep 25, 2025
Merged

Update next_funding spec requirements #4098

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9c2ead2
Update commitment_signed retransmission for next_funding
jkczyz Sep 19, 2025
e083a2d
Document some channel_reestablish spec requirements
jkczyz Sep 19, 2025
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37 changes: 29 additions & 8 deletions lightning/src/ln/channel.rs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -9380,6 +9380,10 @@ where
return Err(ChannelError::close("Peer sent a loose channel_reestablish not after reconnect".to_owned()));
}

// A node:
// - if `next_commitment_number` is zero:
// - MUST immediately fail the channel and broadcast any relevant latest commitment
// transaction.
if msg.next_local_commitment_number == 0
|| msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER
|| msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER
Expand DownExpand Up@@ -9451,9 +9455,10 @@ where
let mut tx_signatures = None;
let mut tx_abort = None;

// if next_funding is set:
// A receiving node:
// - if the `next_funding` TLV is set:
if let Some(next_funding) = &msg.next_funding {
// - if `next_funding` matches the latest interactive funding transaction
// - if `next_funding_txid` matches the latest interactive funding transaction
// or the current channel funding transaction:
if let Some(session) = &self.context.interactive_tx_signing_session {
let our_next_funding_txid = session.unsigned_tx().compute_txid();
Expand All@@ -9468,8 +9473,12 @@ where
self.context.expecting_peer_commitment_signed = true;
}

// TODO(splicing): Add comment for spec requirements
if next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned) {
// - if it has not received `tx_signatures` for that funding transaction:
// - if the `commitment_signed` bit is set in `retransmit_flags`:
if !session.has_received_tx_signatures()
&& next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned)
{
// - MUST retransmit its `commitment_signed` for that funding transaction.
let funding = self
.pending_splice
.as_ref()
Expand DownExpand Up@@ -9605,6 +9614,13 @@ where
let is_awaiting_remote_revoke = self.context.channel_state.is_awaiting_remote_revoke();
let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.context.counterparty_next_commitment_transaction_number + if is_awaiting_remote_revoke { 1 } else { 0 };

// A node:
// - if `next_commitment_number` is 1 in both the `channel_reestablish` it
// sent and received:
// - MUST retransmit `channel_ready`.
Comment on lines +9618 to +9620

@wpaulinowpaulinoSep 22, 2025

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While testing, I noticed there's an overlap between this requirement and my_current_funding_locked when splicing. If we open a fresh channel and immediately splice it, we'll retransmit channel_ready after a reconnect since the commitments have not advanced even though we already locked the splice (either explicitly via splice_locked or implicitly via my_current_funding_locked).

@TheBlueMattTheBlueMattSep 23, 2025

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Mmm, probably worth skipping the channel_ready if we have a splice indicator in the reestablish.

@wpaulinowpaulinoSep 23, 2025

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We can probably leave this for a follow-up? Relevant discussion in the spec: lightning/bolts#1160 (comment)

@TheBlueMattTheBlueMattSep 25, 2025

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Sure, will land this then, its otherwise trivial.

// - otherwise:
// - MUST NOT retransmit `channel_ready`, but MAY send `channel_ready` with
// a different `short_channel_id` `alias` field.
let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.holder_commitment_point.next_transaction_number() == 1 {
// We should never have to worry about MonitorUpdateInProgress resending ChannelReady
self.get_channel_ready(logger)
Expand DownExpand Up@@ -11307,26 +11323,31 @@ where
}

fn maybe_get_next_funding(&self) -> Option<msgs::NextFunding> {
// If we've sent `commtiment_signed` for an interactively constructed transaction
// during a signing session, but have not received `tx_signatures` we MUST set `next_funding`
// to the txid of that interactive transaction, else we MUST NOT set it.
// The sending node:
// - if it has sent `commitment_signed` for an interactive transaction construction but
// it has not received `tx_signatures`:
self.context
.interactive_tx_signing_session
.as_ref()
.filter(|session| !session.has_received_tx_signatures())
.map(|signing_session| {
// - MUST include the `next_funding` TLV.
// - MUST set `next_funding_txid` to the txid of that interactive transaction.
let mut next_funding = msgs::NextFunding {
txid: signing_session.unsigned_tx().compute_txid(),
retransmit_flags: 0,
};

// TODO(splicing): Add comment for spec requirements
// - if it has not received `commitment_signed` for this `next_funding_txid`:
// - MUST set the `commitment_signed` bit in `retransmit_flags`.
if !signing_session.has_received_commitment_signed() {
next_funding.retransmit(msgs::NextFundingFlag::CommitmentSigned);
}

next_funding
})
// - otherwise:
// - MUST NOT include the `next_funding` TLV.
}

fn maybe_get_my_current_funding_locked(&self) -> Option<msgs::FundingLocked> {
Expand Down
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

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Update next_funding spec requirements#4098

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 Merged

TheBlueMatt
merged 2 commits into

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Sep 25, 2025
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Update next_funding spec requirements
#4098
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9c2ead2

Update commitment_signed retransmission for next_funding


jkczyz Sep 19, 2025
e083a2d

Document some channel_reestablish spec requirements


jkczyz Sep 19, 2025

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37 changes: 29 additions & 8 deletions
lightning/src/ln/channel.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -9380,6 +9380,10 @@ where
 return Err(ChannelError::close("Peer sent a loose channel_reestablish not after reconnect".to_owned()));
 }

 // A node:
 // - if `next_commitment_number` is zero:
 // - MUST immediately fail the channel and broadcast any relevant latest commitment
 // transaction.
 if msg.next_local_commitment_number == 0
 || msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER
 || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER
Expand DownExpand Up@@ -9451,9 +9455,10 @@ where
 let mut tx_signatures = None;
 let mut tx_abort = None;

 // if next_funding is set:
 // A receiving node:
 // - if the `next_funding` TLV is set:
 if let Some(next_funding) = &msg.next_funding {
 // - if `next_funding` matches the latest interactive funding transaction
 // - if `next_funding_txid` matches the latest interactive funding transaction
 // or the current channel funding transaction:
 if let Some(session) = &self.context.interactive_tx_signing_session {
 let our_next_funding_txid = session.unsigned_tx().compute_txid();
Expand All@@ -9468,8 +9473,12 @@ where
 self.context.expecting_peer_commitment_signed = true;
 }

 // TODO(splicing): Add comment for spec requirements
 if next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned) {
 // - if it has not received `tx_signatures` for that funding transaction:
 // - if the `commitment_signed` bit is set in `retransmit_flags`:
 if !session.has_received_tx_signatures()
 && next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned)
 {
 // - MUST retransmit its `commitment_signed` for that funding transaction.
 let funding = self
 .pending_splice
 .as_ref()
Expand DownExpand Up@@ -9605,6 +9614,13 @@ where
 let is_awaiting_remote_revoke = self.context.channel_state.is_awaiting_remote_revoke();
 let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.context.counterparty_next_commitment_transaction_number + if is_awaiting_remote_revoke { 1 } else { 0 };

 // A node:
 // - if `next_commitment_number` is 1 in both the `channel_reestablish` it
 // sent and received:
 // - MUST retransmit `channel_ready`.

Comment on lines

+9618
 to 
+9620

@wpaulinowpaulinoSep 22, 2025

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While testing, I noticed there's an overlap between this requirement and my_current_funding_locked when splicing. If we open a fresh channel and immediately splice it, we'll retransmit channel_ready after a reconnect since the commitments have not advanced even though we already locked the splice (either explicitly via splice_locked or implicitly via my_current_funding_locked).
@TheBlueMattTheBlueMattSep 23, 2025

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Mmm, probably worth skipping the channel_ready if we have a splice indicator in the reestablish.
@wpaulinowpaulinoSep 23, 2025

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We can probably leave this for a follow-up? Relevant discussion in the spec: lightning/bolts#1160 (comment)
@TheBlueMattTheBlueMattSep 25, 2025

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Sure, will land this then, its otherwise trivial.
 // - otherwise:
 // - MUST NOT retransmit `channel_ready`, but MAY send `channel_ready` with
 // a different `short_channel_id` `alias` field.
 let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.holder_commitment_point.next_transaction_number() == 1 {
 // We should never have to worry about MonitorUpdateInProgress resending ChannelReady
 self.get_channel_ready(logger)
Expand DownExpand Up@@ -11307,26 +11323,31 @@ where
	}

	fn maybe_get_next_funding(&self) -> Option<msgs::NextFunding> {
 // If we've sent `commtiment_signed` for an interactively constructed transaction
 // during a signing session, but have not received `tx_signatures` we MUST set `next_funding`
 // to the txid of that interactive transaction, else we MUST NOT set it.
 // The sending node:
 //  - if it has sent `commitment_signed` for an interactive transaction construction but
 //  it has not received `tx_signatures`:
 self.context
 .interactive_tx_signing_session
 .as_ref()
 .filter(|session| !session.has_received_tx_signatures())
 .map(|signing_session| {
 // - MUST include the `next_funding` TLV.
 // - MUST set `next_funding_txid` to the txid of that interactive transaction.
 let mut next_funding = msgs::NextFunding {
 txid: signing_session.unsigned_tx().compute_txid(),
 retransmit_flags: 0,
 };

 // TODO(splicing): Add comment for spec requirements
 // - if it has not received `commitment_signed` for this `next_funding_txid`:
 // - MUST set the `commitment_signed` bit in `retransmit_flags`.
 if !signing_session.has_received_commitment_signed() {
 next_funding.retransmit(msgs::NextFundingFlag::CommitmentSigned);
 }

 next_funding
 })
 // - otherwise:
 // - MUST NOT include the `next_funding` TLV.
	}

	fn maybe_get_my_current_funding_locked(&self) -> Option<msgs::FundingLocked> {
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Update next_funding spec requirements#4098

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 Merged

TheBlueMatt
merged 2 commits into

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Sep 25, 2025
 Merged


Update next_funding spec requirements
#4098
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9c2ead2

Update commitment_signed retransmission for next_funding


jkczyz Sep 19, 2025
e083a2d

Document some channel_reestablish spec requirements


jkczyz Sep 19, 2025

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37 changes: 29 additions & 8 deletions
lightning/src/ln/channel.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -9380,6 +9380,10 @@ where
 return Err(ChannelError::close("Peer sent a loose channel_reestablish not after reconnect".to_owned()));
 }

 // A node:
 // - if `next_commitment_number` is zero:
 // - MUST immediately fail the channel and broadcast any relevant latest commitment
 // transaction.
 if msg.next_local_commitment_number == 0
 || msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER
 || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER
Expand DownExpand Up@@ -9451,9 +9455,10 @@ where
 let mut tx_signatures = None;
 let mut tx_abort = None;

 // if next_funding is set:
 // A receiving node:
 // - if the `next_funding` TLV is set:
 if let Some(next_funding) = &msg.next_funding {
 // - if `next_funding` matches the latest interactive funding transaction
 // - if `next_funding_txid` matches the latest interactive funding transaction
 // or the current channel funding transaction:
 if let Some(session) = &self.context.interactive_tx_signing_session {
 let our_next_funding_txid = session.unsigned_tx().compute_txid();
Expand All@@ -9468,8 +9473,12 @@ where
 self.context.expecting_peer_commitment_signed = true;
 }

 // TODO(splicing): Add comment for spec requirements
 if next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned) {
 // - if it has not received `tx_signatures` for that funding transaction:
 // - if the `commitment_signed` bit is set in `retransmit_flags`:
 if !session.has_received_tx_signatures()
 && next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned)
 {
 // - MUST retransmit its `commitment_signed` for that funding transaction.
 let funding = self
 .pending_splice
 .as_ref()
Expand DownExpand Up@@ -9605,6 +9614,13 @@ where
 let is_awaiting_remote_revoke = self.context.channel_state.is_awaiting_remote_revoke();
 let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.context.counterparty_next_commitment_transaction_number + if is_awaiting_remote_revoke { 1 } else { 0 };

 // A node:
 // - if `next_commitment_number` is 1 in both the `channel_reestablish` it
 // sent and received:
 // - MUST retransmit `channel_ready`.

Comment on lines

+9618
 to 
+9620

@wpaulinowpaulinoSep 22, 2025

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While testing, I noticed there's an overlap between this requirement and my_current_funding_locked when splicing. If we open a fresh channel and immediately splice it, we'll retransmit channel_ready after a reconnect since the commitments have not advanced even though we already locked the splice (either explicitly via splice_locked or implicitly via my_current_funding_locked).
@TheBlueMattTheBlueMattSep 23, 2025

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Mmm, probably worth skipping the channel_ready if we have a splice indicator in the reestablish.
@wpaulinowpaulinoSep 23, 2025

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We can probably leave this for a follow-up? Relevant discussion in the spec: lightning/bolts#1160 (comment)
@TheBlueMattTheBlueMattSep 25, 2025

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Sure, will land this then, its otherwise trivial.
 // - otherwise:
 // - MUST NOT retransmit `channel_ready`, but MAY send `channel_ready` with
 // a different `short_channel_id` `alias` field.
 let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.holder_commitment_point.next_transaction_number() == 1 {
 // We should never have to worry about MonitorUpdateInProgress resending ChannelReady
 self.get_channel_ready(logger)
Expand DownExpand Up@@ -11307,26 +11323,31 @@ where
	}

	fn maybe_get_next_funding(&self) -> Option<msgs::NextFunding> {
 // If we've sent `commtiment_signed` for an interactively constructed transaction
 // during a signing session, but have not received `tx_signatures` we MUST set `next_funding`
 // to the txid of that interactive transaction, else we MUST NOT set it.
 // The sending node:
 //  - if it has sent `commitment_signed` for an interactive transaction construction but
 //  it has not received `tx_signatures`:
 self.context
 .interactive_tx_signing_session
 .as_ref()
 .filter(|session| !session.has_received_tx_signatures())
 .map(|signing_session| {
 // - MUST include the `next_funding` TLV.
 // - MUST set `next_funding_txid` to the txid of that interactive transaction.
 let mut next_funding = msgs::NextFunding {
 txid: signing_session.unsigned_tx().compute_txid(),
 retransmit_flags: 0,
 };

 // TODO(splicing): Add comment for spec requirements
 // - if it has not received `commitment_signed` for this `next_funding_txid`:
 // - MUST set the `commitment_signed` bit in `retransmit_flags`.
 if !signing_session.has_received_commitment_signed() {
 next_funding.retransmit(msgs::NextFundingFlag::CommitmentSigned);
 }

 next_funding
 })
 // - otherwise:
 // - MUST NOT include the `next_funding` TLV.
	}

	fn maybe_get_my_current_funding_locked(&self) -> Option<msgs::FundingLocked> {
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Update next_funding spec requirements#4098

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 Merged

TheBlueMatt
merged 2 commits into

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Sep 25, 2025
 Merged


Update next_funding spec requirements
#4098
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2 commits


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9c2ead2

Update commitment_signed retransmission for next_funding


jkczyz Sep 19, 2025
e083a2d

Document some channel_reestablish spec requirements


jkczyz Sep 19, 2025

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37 changes: 29 additions & 8 deletions
lightning/src/ln/channel.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -9380,6 +9380,10 @@ where
 return Err(ChannelError::close("Peer sent a loose channel_reestablish not after reconnect".to_owned()));
 }

 // A node:
 // - if `next_commitment_number` is zero:
 // - MUST immediately fail the channel and broadcast any relevant latest commitment
 // transaction.
 if msg.next_local_commitment_number == 0
 || msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER
 || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER
Expand DownExpand Up@@ -9451,9 +9455,10 @@ where
 let mut tx_signatures = None;
 let mut tx_abort = None;

 // if next_funding is set:
 // A receiving node:
 // - if the `next_funding` TLV is set:
 if let Some(next_funding) = &msg.next_funding {
 // - if `next_funding` matches the latest interactive funding transaction
 // - if `next_funding_txid` matches the latest interactive funding transaction
 // or the current channel funding transaction:
 if let Some(session) = &self.context.interactive_tx_signing_session {
 let our_next_funding_txid = session.unsigned_tx().compute_txid();
Expand All@@ -9468,8 +9473,12 @@ where
 self.context.expecting_peer_commitment_signed = true;
 }

 // TODO(splicing): Add comment for spec requirements
 if next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned) {
 // - if it has not received `tx_signatures` for that funding transaction:
 // - if the `commitment_signed` bit is set in `retransmit_flags`:
 if !session.has_received_tx_signatures()
 && next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned)
 {
 // - MUST retransmit its `commitment_signed` for that funding transaction.
 let funding = self
 .pending_splice
 .as_ref()
Expand DownExpand Up@@ -9605,6 +9614,13 @@ where
 let is_awaiting_remote_revoke = self.context.channel_state.is_awaiting_remote_revoke();
 let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.context.counterparty_next_commitment_transaction_number + if is_awaiting_remote_revoke { 1 } else { 0 };

 // A node:
 // - if `next_commitment_number` is 1 in both the `channel_reestablish` it
 // sent and received:
 // - MUST retransmit `channel_ready`.

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+9620

@wpaulinowpaulinoSep 22, 2025

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While testing, I noticed there's an overlap between this requirement and my_current_funding_locked when splicing. If we open a fresh channel and immediately splice it, we'll retransmit channel_ready after a reconnect since the commitments have not advanced even though we already locked the splice (either explicitly via splice_locked or implicitly via my_current_funding_locked).
@TheBlueMattTheBlueMattSep 23, 2025

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Mmm, probably worth skipping the channel_ready if we have a splice indicator in the reestablish.
@wpaulinowpaulinoSep 23, 2025

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We can probably leave this for a follow-up? Relevant discussion in the spec: lightning/bolts#1160 (comment)
@TheBlueMattTheBlueMattSep 25, 2025

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Sure, will land this then, its otherwise trivial.
 // - otherwise:
 // - MUST NOT retransmit `channel_ready`, but MAY send `channel_ready` with
 // a different `short_channel_id` `alias` field.
 let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.holder_commitment_point.next_transaction_number() == 1 {
 // We should never have to worry about MonitorUpdateInProgress resending ChannelReady
 self.get_channel_ready(logger)
Expand DownExpand Up@@ -11307,26 +11323,31 @@ where
	}

	fn maybe_get_next_funding(&self) -> Option<msgs::NextFunding> {
 // If we've sent `commtiment_signed` for an interactively constructed transaction
 // during a signing session, but have not received `tx_signatures` we MUST set `next_funding`
 // to the txid of that interactive transaction, else we MUST NOT set it.
 // The sending node:
 //  - if it has sent `commitment_signed` for an interactive transaction construction but
 //  it has not received `tx_signatures`:
 self.context
 .interactive_tx_signing_session
 .as_ref()
 .filter(|session| !session.has_received_tx_signatures())
 .map(|signing_session| {
 // - MUST include the `next_funding` TLV.
 // - MUST set `next_funding_txid` to the txid of that interactive transaction.
 let mut next_funding = msgs::NextFunding {
 txid: signing_session.unsigned_tx().compute_txid(),
 retransmit_flags: 0,
 };

 // TODO(splicing): Add comment for spec requirements
 // - if it has not received `commitment_signed` for this `next_funding_txid`:
 // - MUST set the `commitment_signed` bit in `retransmit_flags`.
 if !signing_session.has_received_commitment_signed() {
 next_funding.retransmit(msgs::NextFundingFlag::CommitmentSigned);
 }

 next_funding
 })
 // - otherwise:
 // - MUST NOT include the `next_funding` TLV.
	}

	fn maybe_get_my_current_funding_locked(&self) -> Option<msgs::FundingLocked> {
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

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Update next_funding spec requirements#4098

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TheBlueMatt
merged 2 commits into

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Update next_funding spec requirements
#4098
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9c2ead2

Update commitment_signed retransmission for next_funding


jkczyz Sep 19, 2025
e083a2d

Document some channel_reestablish spec requirements


jkczyz Sep 19, 2025

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37 changes: 29 additions & 8 deletions
lightning/src/ln/channel.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -9380,6 +9380,10 @@ where
 return Err(ChannelError::close("Peer sent a loose channel_reestablish not after reconnect".to_owned()));
 }

 // A node:
 // - if `next_commitment_number` is zero:
 // - MUST immediately fail the channel and broadcast any relevant latest commitment
 // transaction.
 if msg.next_local_commitment_number == 0
 || msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER
 || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER
Expand DownExpand Up@@ -9451,9 +9455,10 @@ where
 let mut tx_signatures = None;
 let mut tx_abort = None;

 // if next_funding is set:
 // A receiving node:
 // - if the `next_funding` TLV is set:
 if let Some(next_funding) = &msg.next_funding {
 // - if `next_funding` matches the latest interactive funding transaction
 // - if `next_funding_txid` matches the latest interactive funding transaction
 // or the current channel funding transaction:
 if let Some(session) = &self.context.interactive_tx_signing_session {
 let our_next_funding_txid = session.unsigned_tx().compute_txid();
Expand All@@ -9468,8 +9473,12 @@ where
 self.context.expecting_peer_commitment_signed = true;
 }

 // TODO(splicing): Add comment for spec requirements
 if next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned) {
 // - if it has not received `tx_signatures` for that funding transaction:
 // - if the `commitment_signed` bit is set in `retransmit_flags`:
 if !session.has_received_tx_signatures()
 && next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned)
 {
 // - MUST retransmit its `commitment_signed` for that funding transaction.
 let funding = self
 .pending_splice
 .as_ref()
Expand DownExpand Up@@ -9605,6 +9614,13 @@ where
 let is_awaiting_remote_revoke = self.context.channel_state.is_awaiting_remote_revoke();
 let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.context.counterparty_next_commitment_transaction_number + if is_awaiting_remote_revoke { 1 } else { 0 };

 // A node:
 // - if `next_commitment_number` is 1 in both the `channel_reestablish` it
 // sent and received:
 // - MUST retransmit `channel_ready`.

Comment on lines

+9618
 to 
+9620

@wpaulinowpaulinoSep 22, 2025

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While testing, I noticed there's an overlap between this requirement and my_current_funding_locked when splicing. If we open a fresh channel and immediately splice it, we'll retransmit channel_ready after a reconnect since the commitments have not advanced even though we already locked the splice (either explicitly via splice_locked or implicitly via my_current_funding_locked).
@TheBlueMattTheBlueMattSep 23, 2025

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Mmm, probably worth skipping the channel_ready if we have a splice indicator in the reestablish.
@wpaulinowpaulinoSep 23, 2025

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We can probably leave this for a follow-up? Relevant discussion in the spec: lightning/bolts#1160 (comment)
@TheBlueMattTheBlueMattSep 25, 2025

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Sure, will land this then, its otherwise trivial.
 // - otherwise:
 // - MUST NOT retransmit `channel_ready`, but MAY send `channel_ready` with
 // a different `short_channel_id` `alias` field.
 let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.holder_commitment_point.next_transaction_number() == 1 {
 // We should never have to worry about MonitorUpdateInProgress resending ChannelReady
 self.get_channel_ready(logger)
Expand DownExpand Up@@ -11307,26 +11323,31 @@ where
	}

	fn maybe_get_next_funding(&self) -> Option<msgs::NextFunding> {
 // If we've sent `commtiment_signed` for an interactively constructed transaction
 // during a signing session, but have not received `tx_signatures` we MUST set `next_funding`
 // to the txid of that interactive transaction, else we MUST NOT set it.
 // The sending node:
 //  - if it has sent `commitment_signed` for an interactive transaction construction but
 //  it has not received `tx_signatures`:
 self.context
 .interactive_tx_signing_session
 .as_ref()
 .filter(|session| !session.has_received_tx_signatures())
 .map(|signing_session| {
 // - MUST include the `next_funding` TLV.
 // - MUST set `next_funding_txid` to the txid of that interactive transaction.
 let mut next_funding = msgs::NextFunding {
 txid: signing_session.unsigned_tx().compute_txid(),
 retransmit_flags: 0,
 };

 // TODO(splicing): Add comment for spec requirements
 // - if it has not received `commitment_signed` for this `next_funding_txid`:
 // - MUST set the `commitment_signed` bit in `retransmit_flags`.
 if !signing_session.has_received_commitment_signed() {
 next_funding.retransmit(msgs::NextFundingFlag::CommitmentSigned);
 }

 next_funding
 })
 // - otherwise:
 // - MUST NOT include the `next_funding` TLV.
	}

	fn maybe_get_my_current_funding_locked(&self) -> Option<msgs::FundingLocked> {
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Update next_funding spec requirements#4098

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 Merged

TheBlueMatt
merged 2 commits into

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Sep 25, 2025
 Merged


Update next_funding spec requirements
#4098
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9c2ead2

Update commitment_signed retransmission for next_funding


jkczyz Sep 19, 2025
e083a2d

Document some channel_reestablish spec requirements


jkczyz Sep 19, 2025

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37 changes: 29 additions & 8 deletions
lightning/src/ln/channel.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -9380,6 +9380,10 @@ where
 return Err(ChannelError::close("Peer sent a loose channel_reestablish not after reconnect".to_owned()));
 }

 // A node:
 // - if `next_commitment_number` is zero:
 // - MUST immediately fail the channel and broadcast any relevant latest commitment
 // transaction.
 if msg.next_local_commitment_number == 0
 || msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER
 || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER
Expand DownExpand Up@@ -9451,9 +9455,10 @@ where
 let mut tx_signatures = None;
 let mut tx_abort = None;

 // if next_funding is set:
 // A receiving node:
 // - if the `next_funding` TLV is set:
 if let Some(next_funding) = &msg.next_funding {
 // - if `next_funding` matches the latest interactive funding transaction
 // - if `next_funding_txid` matches the latest interactive funding transaction
 // or the current channel funding transaction:
 if let Some(session) = &self.context.interactive_tx_signing_session {
 let our_next_funding_txid = session.unsigned_tx().compute_txid();
Expand All@@ -9468,8 +9473,12 @@ where
 self.context.expecting_peer_commitment_signed = true;
 }

 // TODO(splicing): Add comment for spec requirements
 if next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned) {
 // - if it has not received `tx_signatures` for that funding transaction:
 // - if the `commitment_signed` bit is set in `retransmit_flags`:
 if !session.has_received_tx_signatures()
 && next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned)
 {
 // - MUST retransmit its `commitment_signed` for that funding transaction.
 let funding = self
 .pending_splice
 .as_ref()
Expand DownExpand Up@@ -9605,6 +9614,13 @@ where
 let is_awaiting_remote_revoke = self.context.channel_state.is_awaiting_remote_revoke();
 let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.context.counterparty_next_commitment_transaction_number + if is_awaiting_remote_revoke { 1 } else { 0 };

 // A node:
 // - if `next_commitment_number` is 1 in both the `channel_reestablish` it
 // sent and received:
 // - MUST retransmit `channel_ready`.

Comment on lines

+9618
 to 
+9620

@wpaulinowpaulinoSep 22, 2025

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While testing, I noticed there's an overlap between this requirement and my_current_funding_locked when splicing. If we open a fresh channel and immediately splice it, we'll retransmit channel_ready after a reconnect since the commitments have not advanced even though we already locked the splice (either explicitly via splice_locked or implicitly via my_current_funding_locked).
@TheBlueMattTheBlueMattSep 23, 2025

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Mmm, probably worth skipping the channel_ready if we have a splice indicator in the reestablish.
@wpaulinowpaulinoSep 23, 2025

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We can probably leave this for a follow-up? Relevant discussion in the spec: lightning/bolts#1160 (comment)
@TheBlueMattTheBlueMattSep 25, 2025

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Sure, will land this then, its otherwise trivial.
 // - otherwise:
 // - MUST NOT retransmit `channel_ready`, but MAY send `channel_ready` with
 // a different `short_channel_id` `alias` field.
 let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.holder_commitment_point.next_transaction_number() == 1 {
 // We should never have to worry about MonitorUpdateInProgress resending ChannelReady
 self.get_channel_ready(logger)
Expand DownExpand Up@@ -11307,26 +11323,31 @@ where
	}

	fn maybe_get_next_funding(&self) -> Option<msgs::NextFunding> {
 // If we've sent `commtiment_signed` for an interactively constructed transaction
 // during a signing session, but have not received `tx_signatures` we MUST set `next_funding`
 // to the txid of that interactive transaction, else we MUST NOT set it.
 // The sending node:
 //  - if it has sent `commitment_signed` for an interactive transaction construction but
 //  it has not received `tx_signatures`:
 self.context
 .interactive_tx_signing_session
 .as_ref()
 .filter(|session| !session.has_received_tx_signatures())
 .map(|signing_session| {
 // - MUST include the `next_funding` TLV.
 // - MUST set `next_funding_txid` to the txid of that interactive transaction.
 let mut next_funding = msgs::NextFunding {
 txid: signing_session.unsigned_tx().compute_txid(),
 retransmit_flags: 0,
 };

 // TODO(splicing): Add comment for spec requirements
 // - if it has not received `commitment_signed` for this `next_funding_txid`:
 // - MUST set the `commitment_signed` bit in `retransmit_flags`.
 if !signing_session.has_received_commitment_signed() {
 next_funding.retransmit(msgs::NextFundingFlag::CommitmentSigned);
 }

 next_funding
 })
 // - otherwise:
 // - MUST NOT include the `next_funding` TLV.
	}

	fn maybe_get_my_current_funding_locked(&self) -> Option<msgs::FundingLocked> {
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Update next_funding spec requirements#4098

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 Merged

TheBlueMatt
merged 2 commits into

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Sep 25, 2025
 Merged


Update next_funding spec requirements
#4098
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9c2ead2

Update commitment_signed retransmission for next_funding


jkczyz Sep 19, 2025
e083a2d

Document some channel_reestablish spec requirements


jkczyz Sep 19, 2025

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37 changes: 29 additions & 8 deletions
lightning/src/ln/channel.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -9380,6 +9380,10 @@ where
 return Err(ChannelError::close("Peer sent a loose channel_reestablish not after reconnect".to_owned()));
 }

 // A node:
 // - if `next_commitment_number` is zero:
 // - MUST immediately fail the channel and broadcast any relevant latest commitment
 // transaction.
 if msg.next_local_commitment_number == 0
 || msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER
 || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER
Expand DownExpand Up@@ -9451,9 +9455,10 @@ where
 let mut tx_signatures = None;
 let mut tx_abort = None;

 // if next_funding is set:
 // A receiving node:
 // - if the `next_funding` TLV is set:
 if let Some(next_funding) = &msg.next_funding {
 // - if `next_funding` matches the latest interactive funding transaction
 // - if `next_funding_txid` matches the latest interactive funding transaction
 // or the current channel funding transaction:
 if let Some(session) = &self.context.interactive_tx_signing_session {
 let our_next_funding_txid = session.unsigned_tx().compute_txid();
Expand All@@ -9468,8 +9473,12 @@ where
 self.context.expecting_peer_commitment_signed = true;
 }

 // TODO(splicing): Add comment for spec requirements
 if next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned) {
 // - if it has not received `tx_signatures` for that funding transaction:
 // - if the `commitment_signed` bit is set in `retransmit_flags`:
 if !session.has_received_tx_signatures()
 && next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned)
 {
 // - MUST retransmit its `commitment_signed` for that funding transaction.
 let funding = self
 .pending_splice
 .as_ref()
Expand DownExpand Up@@ -9605,6 +9614,13 @@ where
 let is_awaiting_remote_revoke = self.context.channel_state.is_awaiting_remote_revoke();
 let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.context.counterparty_next_commitment_transaction_number + if is_awaiting_remote_revoke { 1 } else { 0 };

 // A node:
 // - if `next_commitment_number` is 1 in both the `channel_reestablish` it
 // sent and received:
 // - MUST retransmit `channel_ready`.

Comment on lines

+9618
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+9620

@wpaulinowpaulinoSep 22, 2025

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While testing, I noticed there's an overlap between this requirement and my_current_funding_locked when splicing. If we open a fresh channel and immediately splice it, we'll retransmit channel_ready after a reconnect since the commitments have not advanced even though we already locked the splice (either explicitly via splice_locked or implicitly via my_current_funding_locked).
@TheBlueMattTheBlueMattSep 23, 2025

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Mmm, probably worth skipping the channel_ready if we have a splice indicator in the reestablish.
@wpaulinowpaulinoSep 23, 2025

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We can probably leave this for a follow-up? Relevant discussion in the spec: lightning/bolts#1160 (comment)
@TheBlueMattTheBlueMattSep 25, 2025

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Sure, will land this then, its otherwise trivial.
 // - otherwise:
 // - MUST NOT retransmit `channel_ready`, but MAY send `channel_ready` with
 // a different `short_channel_id` `alias` field.
 let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.holder_commitment_point.next_transaction_number() == 1 {
 // We should never have to worry about MonitorUpdateInProgress resending ChannelReady
 self.get_channel_ready(logger)
Expand DownExpand Up@@ -11307,26 +11323,31 @@ where
	}

	fn maybe_get_next_funding(&self) -> Option<msgs::NextFunding> {
 // If we've sent `commtiment_signed` for an interactively constructed transaction
 // during a signing session, but have not received `tx_signatures` we MUST set `next_funding`
 // to the txid of that interactive transaction, else we MUST NOT set it.
 // The sending node:
 //  - if it has sent `commitment_signed` for an interactive transaction construction but
 //  it has not received `tx_signatures`:
 self.context
 .interactive_tx_signing_session
 .as_ref()
 .filter(|session| !session.has_received_tx_signatures())
 .map(|signing_session| {
 // - MUST include the `next_funding` TLV.
 // - MUST set `next_funding_txid` to the txid of that interactive transaction.
 let mut next_funding = msgs::NextFunding {
 txid: signing_session.unsigned_tx().compute_txid(),
 retransmit_flags: 0,
 };

 // TODO(splicing): Add comment for spec requirements
 // - if it has not received `commitment_signed` for this `next_funding_txid`:
 // - MUST set the `commitment_signed` bit in `retransmit_flags`.
 if !signing_session.has_received_commitment_signed() {
 next_funding.retransmit(msgs::NextFundingFlag::CommitmentSigned);
 }

 next_funding
 })
 // - otherwise:
 // - MUST NOT include the `next_funding` TLV.
	}

	fn maybe_get_my_current_funding_locked(&self) -> Option<msgs::FundingLocked> {
Expand Down
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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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Update next_funding spec requirements#4098

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 Merged

TheBlueMatt
merged 2 commits into

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Sep 25, 2025
 Merged


Update next_funding spec requirements
#4098
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9c2ead2

Update commitment_signed retransmission for next_funding


jkczyz Sep 19, 2025
e083a2d

Document some channel_reestablish spec requirements


jkczyz Sep 19, 2025

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37 changes: 29 additions & 8 deletions
lightning/src/ln/channel.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -9380,6 +9380,10 @@ where
 return Err(ChannelError::close("Peer sent a loose channel_reestablish not after reconnect".to_owned()));
 }

 // A node:
 // - if `next_commitment_number` is zero:
 // - MUST immediately fail the channel and broadcast any relevant latest commitment
 // transaction.
 if msg.next_local_commitment_number == 0
 || msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER
 || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER
Expand DownExpand Up@@ -9451,9 +9455,10 @@ where
 let mut tx_signatures = None;
 let mut tx_abort = None;

 // if next_funding is set:
 // A receiving node:
 // - if the `next_funding` TLV is set:
 if let Some(next_funding) = &msg.next_funding {
 // - if `next_funding` matches the latest interactive funding transaction
 // - if `next_funding_txid` matches the latest interactive funding transaction
 // or the current channel funding transaction:
 if let Some(session) = &self.context.interactive_tx_signing_session {
 let our_next_funding_txid = session.unsigned_tx().compute_txid();
Expand All@@ -9468,8 +9473,12 @@ where
 self.context.expecting_peer_commitment_signed = true;
 }

 // TODO(splicing): Add comment for spec requirements
 if next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned) {
 // - if it has not received `tx_signatures` for that funding transaction:
 // - if the `commitment_signed` bit is set in `retransmit_flags`:
 if !session.has_received_tx_signatures()
 && next_funding.should_retransmit(msgs::NextFundingFlag::CommitmentSigned)
 {
 // - MUST retransmit its `commitment_signed` for that funding transaction.
 let funding = self
 .pending_splice
 .as_ref()
Expand DownExpand Up@@ -9605,6 +9614,13 @@ where
 let is_awaiting_remote_revoke = self.context.channel_state.is_awaiting_remote_revoke();
 let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.context.counterparty_next_commitment_transaction_number + if is_awaiting_remote_revoke { 1 } else { 0 };

 // A node:
 // - if `next_commitment_number` is 1 in both the `channel_reestablish` it
 // sent and received:
 // - MUST retransmit `channel_ready`.

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@wpaulinowpaulinoSep 22, 2025

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While testing, I noticed there's an overlap between this requirement and my_current_funding_locked when splicing. If we open a fresh channel and immediately splice it, we'll retransmit channel_ready after a reconnect since the commitments have not advanced even though we already locked the splice (either explicitly via splice_locked or implicitly via my_current_funding_locked).
@TheBlueMattTheBlueMattSep 23, 2025

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Mmm, probably worth skipping the channel_ready if we have a splice indicator in the reestablish.
@wpaulinowpaulinoSep 23, 2025

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We can probably leave this for a follow-up? Relevant discussion in the spec: lightning/bolts#1160 (comment)
@TheBlueMattTheBlueMattSep 25, 2025

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Sure, will land this then, its otherwise trivial.
 // - otherwise:
 // - MUST NOT retransmit `channel_ready`, but MAY send `channel_ready` with
 // a different `short_channel_id` `alias` field.
 let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.holder_commitment_point.next_transaction_number() == 1 {
 // We should never have to worry about MonitorUpdateInProgress resending ChannelReady
 self.get_channel_ready(logger)
Expand DownExpand Up@@ -11307,26 +11323,31 @@ where
	}

	fn maybe_get_next_funding(&self) -> Option<msgs::NextFunding> {
 // If we've sent `commtiment_signed` for an interactively constructed transaction
 // during a signing session, but have not received `tx_signatures` we MUST set `next_funding`
 // to the txid of that interactive transaction, else we MUST NOT set it.
 // The sending node:
 //  - if it has sent `commitment_signed` for an interactive transaction construction but
 //  it has not received `tx_signatures`:
 self.context
 .interactive_tx_signing_session
 .as_ref()
 .filter(|session| !session.has_received_tx_signatures())
 .map(|signing_session| {
 // - MUST include the `next_funding` TLV.
 // - MUST set `next_funding_txid` to the txid of that interactive transaction.
 let mut next_funding = msgs::NextFunding {
 txid: signing_session.unsigned_tx().compute_txid(),
 retransmit_flags: 0,
 };

 // TODO(splicing): Add comment for spec requirements
 // - if it has not received `commitment_signed` for this `next_funding_txid`:
 // - MUST set the `commitment_signed` bit in `retransmit_flags`.
 if !signing_session.has_received_commitment_signed() {
 next_funding.retransmit(msgs::NextFundingFlag::CommitmentSigned);
 }

 next_funding
 })
 // - otherwise:
 // - MUST NOT include the `next_funding` TLV.
	}

	fn maybe_get_my_current_funding_locked(&self) -> Option<msgs::FundingLocked> {
Expand Down
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