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Add liquidity checks and improve payment error handling #3175

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b2c3ddb
Refactor amount validation and relocate currency check
slanesuke Jul 18, 2024
e7edc86
f Remove currency validation from parsing code
slanesuke Aug 26, 2024
2f029a9
Move currency check to `OffersMessageHandler`
slanesuke Aug 26, 2024
61f7348
Add `Bolt12CreationError` error type
slanesuke Jul 19, 2024
5c8be84
f Revert `Bolt12CreationError` to `Bolt12SemanticError`
slanesuke Aug 23, 2024
6f9ac11
Add a `Bolt12RequestError` error type
slanesuke Aug 7, 2024
d38acd3
Abort payment if insufficient liquidity in `pay_for_offer`
slanesuke Jul 12, 2024
7dfcbc5
Add test for insufficient liquidity in `pay_for_offer`
slanesuke Jul 23, 2024
f6f752f
Add tests for `Offers` with fiat amount
slanesuke Jul 25, 2024
15653e8
Update docs for `InvoiceRequestBuilder::amount_msats`
slanesuke Aug 8, 2024
b22a843
Abort `RefundBuilder` creation on insufficient liquidity
slanesuke Aug 7, 2024
7b465f9
Add test for refund creation with insufficient liquidity
slanesuke Aug 24, 2024
f15db05
Validate amount_msats against invoice and refund amounts
slanesuke Aug 8, 2024
35e3daa
Update docs for `Bolt12SemanticError::InvalidAmount`
slanesuke Aug 24, 2024
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138 changes: 115 additions & 23 deletions lightning/src/ln/channelmanager.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -67,7 +67,7 @@ use crate::offers::invoice::{Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, DerivedSign
use crate::offers::invoice_error::InvoiceError;
use crate::offers::invoice_request::{DerivedPayerSigningPubkey, InvoiceRequest, InvoiceRequestBuilder};
use crate::offers::nonce::Nonce;
use crate::offers::offer::{Offer, OfferBuilder};
use crate::offers::offer::{Amount, Offer, OfferBuilder};
use crate::offers::parse::Bolt12SemanticError;
use crate::offers::refund::{Refund, RefundBuilder};
use crate::offers::signer;
Expand Down Expand Up @@ -1844,10 +1844,9 @@ where
///
/// ```
/// # use lightning::events::{Event, EventsProvider, PaymentPurpose};
/// # use lightning::ln::channelmanager::AChannelManager;
/// # use lightning::offers::parse::Bolt12SemanticError;
/// # use lightning::ln::channelmanager::{AChannelManager, Bolt12CreationError};
/// #
/// # fn example<T: AChannelManager>(channel_manager: T) -> Result<(), Bolt12SemanticError> {
/// # fn example<T: AChannelManager>(channel_manager: T) -> Result<(), Bolt12CreationError> {
/// # let channel_manager = channel_manager.get_cm();
/// # let absolute_expiry = None;
/// let offer = channel_manager
Expand Down Expand Up @@ -1947,13 +1946,12 @@ where
/// ```
/// # use core::time::Duration;
/// # use lightning::events::{Event, EventsProvider};
/// # use lightning::ln::channelmanager::{AChannelManager, PaymentId, RecentPaymentDetails, Retry};
/// # use lightning::offers::parse::Bolt12SemanticError;
/// # use lightning::ln::channelmanager::{AChannelManager, Bolt12RequestError, PaymentId, RecentPaymentDetails, Retry};
/// #
/// # fn example<T: AChannelManager>(
/// # channel_manager: T, amount_msats: u64, absolute_expiry: Duration, retry: Retry,
/// # max_total_routing_fee_msat: Option<u64>
/// # ) -> Result<(), Bolt12SemanticError> {
/// # ) -> Result<(), Bolt12RequestError> {
/// # let channel_manager = channel_manager.get_cm();
/// let payment_id = PaymentId([42; 32]);
/// let refund = channel_manager
Expand Down Expand Up @@ -2685,6 +2683,40 @@ pub enum RecentPaymentDetails {
},
}

/// Error during creation and handling of BOLT 12 related payments.
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The roles of Bolt12CreationError, and Bolt12Response feels a little confusing to me.

For example

It reads during creation and handling of BOLT 12 related payments but technically we are not creating any payment when we are creating an offer.

Maybe we can simplify the enums, by introducing only one new enum called Bolt12CreationError that contains "Error during creation of BOLT12 Messages"?

#[derive(Debug, Clone, PartialEq)]
pub enum Bolt12CreationError {
/// Error from BOLT 12 semantic checks.
InvalidSemantics(Bolt12SemanticError),
/// Failed to create a blinded path.
BlindedPathCreationFailed,
}

impl From<Bolt12SemanticError> for Bolt12CreationError {
fn from(err: Bolt12SemanticError) -> Self {
Bolt12CreationError::InvalidSemantics(err)
}
}

/// Error during requesting a BOLT 12 related payment.
#[derive(Debug, Clone, PartialEq)]
pub enum Bolt12RequestError {
/// Error from BOLT 12 semantic checks.
InvalidSemantics(Bolt12SemanticError),
/// The payment id for a refund or request is already in use.
DuplicatePaymentId,
/// There is insufficient liquidity to complete the payment.
InsufficientLiquidity,
/// Failed to create a blinded path.
BlindedPathCreationFailed,
}

impl From<Bolt12SemanticError> for Bolt12RequestError {
fn from(err: Bolt12SemanticError) -> Self {
Bolt12RequestError::InvalidSemantics(err)
}
}

/// Route hints used in constructing invoices for [phantom node payents].
///
/// [phantom node payments]: crate::sign::PhantomKeysManager
Expand Down Expand Up @@ -9114,7 +9146,7 @@ macro_rules! create_offer_builder { ($self: ident, $builder: ty) => {
/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
pub fn create_offer_builder(
&$self, absolute_expiry: Option<Duration>
) -> Result<$builder, Bolt12SemanticError> {
) -> Result<$builder, Bolt12CreationError> {
let node_id = $self.get_our_node_id();
let expanded_key = &$self.inbound_payment_key;
let entropy = &*$self.entropy_source;
Expand All @@ -9124,7 +9156,7 @@ macro_rules! create_offer_builder { ($self: ident, $builder: ty) => {
let context = OffersContext::InvoiceRequest { nonce };
let path = $self.create_blinded_paths_using_absolute_expiry(context, absolute_expiry)
.and_then(|paths| paths.into_iter().next().ok_or(()))
.map_err(|_| Bolt12SemanticError::MissingPaths)?;
.map_err(|()| Bolt12CreationError::BlindedPathCreationFailed)?;
let builder = OfferBuilder::deriving_signing_pubkey(node_id, expanded_key, nonce, secp_ctx)
.chain_hash($self.chain_hash)
.path(path);
Expand Down Expand Up @@ -9187,7 +9219,7 @@ macro_rules! create_refund_builder { ($self: ident, $builder: ty) => {
pub fn create_refund_builder(
&$self, amount_msats: u64, absolute_expiry: Duration, payment_id: PaymentId,
retry_strategy: Retry, max_total_routing_fee_msat: Option<u64>
) -> Result<$builder, Bolt12SemanticError> {
) -> Result<$builder, Bolt12RequestError> {
let node_id = $self.get_our_node_id();
let expanded_key = &$self.inbound_payment_key;
let entropy = &*$self.entropy_source;
Expand All @@ -9197,7 +9229,28 @@ macro_rules! create_refund_builder { ($self: ident, $builder: ty) => {
let context = OffersContext::OutboundPayment { payment_id, nonce, hmac: None };
let path = $self.create_blinded_paths_using_absolute_expiry(context, Some(absolute_expiry))
.and_then(|paths| paths.into_iter().next().ok_or(()))
.map_err(|_| Bolt12SemanticError::MissingPaths)?;
.map_err(|()| Bolt12RequestError::BlindedPathCreationFailed)?;

let total_liquidity: u64 = {
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@jkczyz

Should we add a similar liquidity check for inbound liquidity? This would be helpful when we are creating an offer, or calling request_refund_payment.

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Offers can be long-lived and be paid more than once. So it would be only be accurate for short-lived, single-use offers. For those and refund payment request, I wonder if that approach is preferable as it allows us to give early indication of a failure to the user. Drawback is it would prevent creating an offer / sending an invoice even if liquidity is soon-but-not-yet available (e.g., future JIT channel work). @tnull Thoughts?

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ISTM we should consider it for refunds since those are also outbound liquidity (and likely to be claimed ~immediately), but for inbound liquidity yea I'd be kinda skeptical of it given JIT channels can come in many forms.

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So IIUC, the outbound liquidity check for refunds makes sense since they’re likely to be claimed quickly. But for inbound liquidity, JIT channels could complicate things. Should we hold off on adding an inbound liquidity check in this PR? I’d appreciate any thoughts on how to proceed!

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Yeah, let's hold off.

let per_peer_state = &$self.per_peer_state.read().unwrap();
let mut sum: u64 = 0;

per_peer_state.iter().for_each(|(_, peer_state_mutex)| {
let peer_state_lock = peer_state_mutex.lock().unwrap();
let peer_state = &*peer_state_lock;

sum += peer_state.channel_by_id
.iter()
.map(|(_, phase)| phase.context().get_available_balances(&$self.fee_estimator).outbound_capacity_msat)
.sum::<u64>();
});
sum
};

if amount_msats > total_liquidity {
log_error!($self.logger, "Insufficient liquidity for payment with payment id: {}", payment_id);
return Err(Bolt12RequestError::InsufficientLiquidity);
}

let builder = RefundBuilder::deriving_signing_pubkey(
node_id, expanded_key, nonce, secp_ctx, amount_msats, payment_id
Expand All @@ -9213,7 +9266,7 @@ macro_rules! create_refund_builder { ($self: ident, $builder: ty) => {
.add_new_awaiting_invoice(
payment_id, expiration, retry_strategy, max_total_routing_fee_msat, None,
)
.map_err(|_| Bolt12SemanticError::DuplicatePaymentId)?;
.map_err(|()| Bolt12RequestError::DuplicatePaymentId)?;

Ok(builder.into())
}
Expand Down Expand Up @@ -9305,7 +9358,7 @@ where
&self, offer: &Offer, quantity: Option<u64>, amount_msats: Option<u64>,
payer_note: Option<String>, payment_id: PaymentId, retry_strategy: Retry,
max_total_routing_fee_msat: Option<u64>
) -> Result<(), Bolt12SemanticError> {
) -> Result<(), Bolt12RequestError> {
let expanded_key = &self.inbound_payment_key;
let entropy = &*self.entropy_source;
let secp_ctx = &self.secp_ctx;
Expand Down Expand Up @@ -9335,7 +9388,38 @@ where
OffersContext::OutboundPayment { payment_id, nonce, hmac: Some(hmac) }
);
let reply_paths = self.create_blinded_paths(context)
.map_err(|_| Bolt12SemanticError::MissingPaths)?;
.map_err(|()| Bolt12RequestError::BlindedPathCreationFailed)?;

let total_liquidity: u64 = {
let per_peer_state = &self.per_peer_state.read().unwrap();
let mut sum: u64 = 0;

per_peer_state.iter().for_each(|(_, peer_state_mutex)| {
let peer_state_lock = peer_state_mutex.lock().unwrap();
let peer_state = &*peer_state_lock;

sum += peer_state.channel_by_id
.iter()
.map(|(_, phase)| phase.context().get_available_balances(&self.fee_estimator).outbound_capacity_msat)
.sum::<u64>();
});
sum
};

let requested_amount_msats = match invoice_request.amount_msats() {
Some(amount_msats) => Some(amount_msats),
None => match offer.amount() {
Some(Amount::Bitcoin { amount_msats }) => Some(amount_msats),
_ => None,
},
};

if let Some(amount) = requested_amount_msats {
if amount > total_liquidity {
log_error!(self.logger, "Insufficient liquidity for payment with payment id: {}", payment_id);
return Err(Bolt12RequestError::InsufficientLiquidity);
}
}
Comment on lines +9417 to +9422
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@tnull Should we consider outstanding invoice requests / refunds?

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Hmm, remind me, what would be the timeout for pending invoice requests, i.e., when would we abort and clear them? Is it one timer tick? Given that we wouldn't consider them for other payment types (BOLT11), it might come as a surprise that you're able to send legacy payments but BOLT12 fails?

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Invoice requests are one tick (so max ~2 ticks if called right after a tick), while refunds are based on the refund's expiration.

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Hmm, no super strong opinion, but maybe we should roughly align the failure cases across different payment types, so maybe not worth?

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Not sure I understand the point. For BOLT11, if we initiate a bunch of payments, each subsequent one will have less liquidity to consider, IIUC. But for BOLT12, we can similarly initiate more than one payment but each subsequent one will consider the same liquidity unless an invoice is received for a prior one.

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Sorry for the late reply! Since outstanding invoice requests and refunds can tie up liquidity, do you think we should check for any outstanding invoices and see how they affect available liquidity before moving forward with the payment? And should I address it in this PR? I want to make sure to cover all our bases.

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So they can potentially use liquidity if an invoice is received in response. But they don't tie up liquidity since a payment hasn't been made yet. That said, we can consider a request for payment as an intention to tie up liquidity in the hopefully near future. I'd lean towards including it but will defer to @tnull.

FWIW, there's also some edge cases to consider. If we have a fiat-denominated offer and the users doesn't give an amount, how much liquidity should we considered unavailable?


let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);

Expand All @@ -9349,16 +9433,17 @@ where
payment_id, expiration, retry_strategy, max_total_routing_fee_msat,
Some(retryable_invoice_request)
)
.map_err(|_| Bolt12SemanticError::DuplicatePaymentId)?;
.map_err(|()| Bolt12RequestError::DuplicatePaymentId)?;

self.enqueue_invoice_request(invoice_request, reply_paths)
self.enqueue_invoice_request(invoice_request, reply_paths)?;
Ok(())
}

fn enqueue_invoice_request(
&self,
invoice_request: InvoiceRequest,
reply_paths: Vec<BlindedMessagePath>,
) -> Result<(), Bolt12SemanticError> {
) -> Result<(), Bolt12RequestError> {
let mut pending_offers_messages = self.pending_offers_messages.lock().unwrap();
if !invoice_request.paths().is_empty() {
reply_paths
Expand All @@ -9384,7 +9469,7 @@ where
}
} else {
debug_assert!(false);
return Err(Bolt12SemanticError::MissingIssuerSigningPubkey);
return Err(Bolt12RequestError::InvalidSemantics(Bolt12SemanticError::MissingIssuerSigningPubkey));
}

Ok(())
Expand Down Expand Up @@ -9414,7 +9499,7 @@ where
/// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
pub fn request_refund_payment(
&self, refund: &Refund
) -> Result<Bolt12Invoice, Bolt12SemanticError> {
) -> Result<Bolt12Invoice, Bolt12CreationError> {
let expanded_key = &self.inbound_payment_key;
let entropy = &*self.entropy_source;
let secp_ctx = &self.secp_ctx;
Expand All @@ -9423,7 +9508,7 @@ where
let relative_expiry = DEFAULT_RELATIVE_EXPIRY.as_secs() as u32;

if refund.chain() != self.chain_hash {
return Err(Bolt12SemanticError::UnsupportedChain);
return Err(Bolt12CreationError::InvalidSemantics(Bolt12SemanticError::UnsupportedChain));
}

let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
Expand All @@ -9434,7 +9519,7 @@ where
let payment_paths = self.create_blinded_payment_paths(
amount_msats, payment_secret, payment_context
)
.map_err(|_| Bolt12SemanticError::MissingPaths)?;
.map_err(|()| Bolt12CreationError::BlindedPathCreationFailed)?;

#[cfg(feature = "std")]
let builder = refund.respond_using_derived_keys(
Expand All @@ -9457,7 +9542,7 @@ where
payment_hash: invoice.payment_hash(), nonce, hmac
});
let reply_paths = self.create_blinded_paths(context)
.map_err(|_| Bolt12SemanticError::MissingPaths)?;
.map_err(|()| Bolt12CreationError::BlindedPathCreationFailed)?;

let mut pending_offers_messages = self.pending_offers_messages.lock().unwrap();
if refund.paths().is_empty() {
Expand Down Expand Up @@ -9486,7 +9571,7 @@ where

Ok(invoice)
},
Err(()) => Err(Bolt12SemanticError::InvalidAmount),
Err(()) => Err(Bolt12CreationError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
}
}

Expand Down Expand Up @@ -11135,6 +11220,13 @@ where
None => return None,
};

if let Some(amount) = invoice_request.amount() {
if let Amount::Currency { .. } = amount {
let error = Bolt12SemanticError::UnsupportedCurrency;
return Some((OffersMessage::InvoiceError(error.into()), responder.respond()));
}
}

let nonce = match context {
None if invoice_request.metadata().is_some() => None,
Some(OffersContext::InvoiceRequest { nonce }) => Some(nonce),
Expand Down
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