From c9ce344d56991ffa49c1867d5041bc136cedbece Mon Sep 17 00:00:00 2001 From: Jeffrey Czyz Date: Tue, 9 Nov 2021 09:37:34 -0600 Subject: [PATCH] Refactor InvoicePayer for spontaneous payments To support spontaneous payments, InvoicePayer's sending logic must be invoice-agnostic. Refactor InvoicePayer::pay_invoice_internal such that invoice-specific code is in pay_invoice_using_amount and the remaining logic is in pay_internal. Further refactor the code's payment_cache locking such that it is accessed consistently when needed, and tidy up the code a bit. --- lightning-invoice/src/payment.rs | 234 +++++++++++++++---------------- 1 file changed, 115 insertions(+), 119 deletions(-) diff --git a/lightning-invoice/src/payment.rs b/lightning-invoice/src/payment.rs index 075559bfd..1a7242b8e 100644 --- a/lightning-invoice/src/payment.rs +++ b/lightning-invoice/src/payment.rs @@ -144,6 +144,7 @@ where scorer: S, logger: L, event_handler: E, + /// Caches the overall attempts at making a payment, which is updated prior to retrying. payment_cache: Mutex>, retry_attempts: RetryAttempts, } @@ -228,7 +229,7 @@ where if invoice.amount_milli_satoshis().is_none() { Err(PaymentError::Invoice("amount missing")) } else { - self.pay_invoice_internal(invoice, None, 0) + self.pay_invoice_using_amount(invoice, None) } } @@ -244,140 +245,135 @@ where if invoice.amount_milli_satoshis().is_some() { Err(PaymentError::Invoice("amount unexpected")) } else { - self.pay_invoice_internal(invoice, Some(amount_msats), 0) + self.pay_invoice_using_amount(invoice, Some(amount_msats)) } } - fn pay_invoice_internal( - &self, invoice: &Invoice, amount_msats: Option, retry_count: usize + fn pay_invoice_using_amount( + &self, invoice: &Invoice, amount_msats: Option ) -> Result { debug_assert!(invoice.amount_milli_satoshis().is_some() ^ amount_msats.is_some()); + let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner()); - if invoice.is_expired() { - log_trace!(self.logger, "Invoice expired prior to first send for payment {}", log_bytes!(payment_hash.0)); + match self.payment_cache.lock().unwrap().entry(payment_hash) { + hash_map::Entry::Occupied(_) => return Err(PaymentError::Invoice("payment pending")), + hash_map::Entry::Vacant(entry) => entry.insert(0), + }; + + let payment_secret = Some(invoice.payment_secret().clone()); + let mut payee = Payee::from_node_id(invoice.recover_payee_pub_key()) + .with_expiry_time(expiry_time_from_unix_epoch(&invoice).as_secs()) + .with_route_hints(invoice.route_hints()); + if let Some(features) = invoice.features() { + payee = payee.with_features(features.clone()); + } + let params = RouteParameters { + payee, + final_value_msat: invoice.amount_milli_satoshis().or(amount_msats).unwrap(), + final_cltv_expiry_delta: invoice.min_final_cltv_expiry() as u32, + }; + + self.pay_internal(¶ms, payment_hash, &payment_secret) + .map_err(|e| { self.payment_cache.lock().unwrap().remove(&payment_hash); e }) + } + + fn pay_internal( + &self, params: &RouteParameters, payment_hash: PaymentHash, + payment_secret: &Option, + ) -> Result { + if has_expired(params) { + log_trace!(self.logger, "Invoice expired prior to send for payment {}", log_bytes!(payment_hash.0)); return Err(PaymentError::Invoice("Invoice expired prior to send")); } - let retry_data_payment_id = loop { - let mut payment_cache = self.payment_cache.lock().unwrap(); - match payment_cache.entry(payment_hash) { - hash_map::Entry::Vacant(entry) => { - let payer = self.payer.node_id(); - let mut payee = Payee::from_node_id(invoice.recover_payee_pub_key()) - .with_expiry_time(expiry_time_from_unix_epoch(&invoice).as_secs()) - .with_route_hints(invoice.route_hints()); - if let Some(features) = invoice.features() { - payee = payee.with_features(features.clone()); + + let payer = self.payer.node_id(); + let first_hops = self.payer.first_hops(); + let route = self.router.find_route( + &payer, + params, + Some(&first_hops.iter().collect::>()), + &self.scorer.lock(), + ).map_err(|e| PaymentError::Routing(e))?; + + match self.payer.send_payment(&route, payment_hash, payment_secret) { + Ok(payment_id) => Ok(payment_id), + Err(e) => match e { + PaymentSendFailure::ParameterError(_) => Err(e), + PaymentSendFailure::PathParameterError(_) => Err(e), + PaymentSendFailure::AllFailedRetrySafe(_) => { + let mut payment_cache = self.payment_cache.lock().unwrap(); + let retry_count = payment_cache.get_mut(&payment_hash).unwrap(); + if *retry_count >= self.retry_attempts.0 { + Err(e) + } else { + *retry_count += 1; + std::mem::drop(payment_cache); + Ok(self.pay_internal(params, payment_hash, payment_secret)?) } - let params = RouteParameters { - payee, - final_value_msat: invoice.amount_milli_satoshis().or(amount_msats).unwrap(), - final_cltv_expiry_delta: invoice.min_final_cltv_expiry() as u32, - }; - let first_hops = self.payer.first_hops(); - let route = self.router.find_route( - &payer, - ¶ms, - Some(&first_hops.iter().collect::>()), - &self.scorer.lock(), - ).map_err(|e| PaymentError::Routing(e))?; - - let payment_secret = Some(invoice.payment_secret().clone()); - let payment_id = match self.payer.send_payment(&route, payment_hash, &payment_secret) { - Ok(payment_id) => payment_id, - Err(PaymentSendFailure::ParameterError(e)) => - return Err(PaymentError::Sending(PaymentSendFailure::ParameterError(e))), - Err(PaymentSendFailure::PathParameterError(e)) => - return Err(PaymentError::Sending(PaymentSendFailure::PathParameterError(e))), - Err(PaymentSendFailure::AllFailedRetrySafe(e)) => { - if retry_count >= self.retry_attempts.0 { - return Err(PaymentError::Sending(PaymentSendFailure::AllFailedRetrySafe(e))) - } - break None; - }, - Err(PaymentSendFailure::PartialFailure { results: _, failed_paths_retry, payment_id }) => { - if let Some(retry_data) = failed_paths_retry { - entry.insert(retry_count); - break Some((retry_data, payment_id)); - } else { - // This may happen if we send a payment and some paths fail, but - // only due to a temporary monitor failure or the like, implying - // they're really in-flight, but we haven't sent the initial - // HTLC-Add messages yet. - payment_id - } - }, - }; - entry.insert(retry_count); - return Ok(payment_id); }, - hash_map::Entry::Occupied(_) => return Err(PaymentError::Invoice("payment pending")), - } - }; - if let Some((retry_data, payment_id)) = retry_data_payment_id { - // Some paths were sent, even if we failed to send the full MPP value our recipient may - // misbehave and claim the funds, at which point we have to consider the payment sent, - // so return `Ok()` here, ignoring any retry errors. - let _ = self.retry_payment(payment_id, payment_hash, &retry_data); - Ok(payment_id) - } else { - self.pay_invoice_internal(invoice, amount_msats, retry_count + 1) - } + PaymentSendFailure::PartialFailure { failed_paths_retry, payment_id, .. } => { + if let Some(retry_data) = failed_paths_retry { + // Some paths were sent, even if we failed to send the full MPP value our + // recipient may misbehave and claim the funds, at which point we have to + // consider the payment sent, so return `Ok()` here, ignoring any retry + // errors. + let _ = self.retry_payment(payment_id, payment_hash, &retry_data); + Ok(payment_id) + } else { + // This may happen if we send a payment and some paths fail, but + // only due to a temporary monitor failure or the like, implying + // they're really in-flight, but we haven't sent the initial + // HTLC-Add messages yet. + Ok(payment_id) + } + }, + }, + }.map_err(|e| PaymentError::Sending(e)) } - fn retry_payment(&self, payment_id: PaymentId, payment_hash: PaymentHash, params: &RouteParameters) - -> Result<(), ()> { - let route; - { - let mut payment_cache = self.payment_cache.lock().unwrap(); - let entry = loop { - let entry = payment_cache.entry(payment_hash); - match entry { - hash_map::Entry::Occupied(_) => break entry, - hash_map::Entry::Vacant(entry) => entry.insert(0), - }; - }; - if let hash_map::Entry::Occupied(mut entry) = entry { - let max_payment_attempts = self.retry_attempts.0 + 1; - let attempts = entry.get_mut(); - *attempts += 1; - - if *attempts >= max_payment_attempts { - log_trace!(self.logger, "Payment {} exceeded maximum attempts; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts); - return Err(()); - } else if has_expired(params) { - log_trace!(self.logger, "Invoice expired for payment {}; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts); - return Err(()); - } + fn retry_payment( + &self, payment_id: PaymentId, payment_hash: PaymentHash, params: &RouteParameters + ) -> Result<(), ()> { + let max_payment_attempts = self.retry_attempts.0 + 1; + let attempts = *self.payment_cache.lock().unwrap() + .entry(payment_hash) + .and_modify(|attempts| *attempts += 1) + .or_insert(1); + + if attempts >= max_payment_attempts { + log_trace!(self.logger, "Payment {} exceeded maximum attempts; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts); + return Err(()); + } - let payer = self.payer.node_id(); - let first_hops = self.payer.first_hops(); - route = self.router.find_route(&payer, ¶ms, Some(&first_hops.iter().collect::>()), &self.scorer.lock()); - if route.is_err() { - log_trace!(self.logger, "Failed to find a route for payment {}; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts); - return Err(()); - } - } else { - unreachable!(); - } + if has_expired(params) { + log_trace!(self.logger, "Invoice expired for payment {}; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts); + return Err(()); + } + + let payer = self.payer.node_id(); + let first_hops = self.payer.first_hops(); + let route = self.router.find_route(&payer, ¶ms, Some(&first_hops.iter().collect::>()), &self.scorer.lock()); + if route.is_err() { + log_trace!(self.logger, "Failed to find a route for payment {}; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts); + return Err(()); } - let retry_res = self.payer.retry_payment(&route.unwrap(), payment_id); - match retry_res { + match self.payer.retry_payment(&route.unwrap(), payment_id) { Ok(()) => Ok(()), Err(PaymentSendFailure::ParameterError(_)) | Err(PaymentSendFailure::PathParameterError(_)) => { log_trace!(self.logger, "Failed to retry for payment {} due to bogus route/payment data, not retrying.", log_bytes!(payment_hash.0)); - return Err(()); + Err(()) }, Err(PaymentSendFailure::AllFailedRetrySafe(_)) => { self.retry_payment(payment_id, payment_hash, params) }, - Err(PaymentSendFailure::PartialFailure { results: _, failed_paths_retry, .. }) => { + Err(PaymentSendFailure::PartialFailure { failed_paths_retry, .. }) => { if let Some(retry) = failed_paths_retry { - self.retry_payment(payment_id, payment_hash, &retry) - } else { - Ok(()) + // Always return Ok for the same reason as noted in pay_internal. + let _ = self.retry_payment(payment_id, payment_hash, &retry); } + Ok(()) }, } } @@ -412,25 +408,25 @@ where fn handle_event(&self, event: &Event) { match event { Event::PaymentPathFailed { - all_paths_failed, payment_id, payment_hash, rejected_by_dest, path, short_channel_id, retry, .. + all_paths_failed, payment_id, payment_hash, rejected_by_dest, path, + short_channel_id, retry, .. } => { if let Some(short_channel_id) = short_channel_id { - let t = path.iter().collect::>(); - self.scorer.lock().payment_path_failed(&t, *short_channel_id); + let path = path.iter().collect::>(); + self.scorer.lock().payment_path_failed(&path, *short_channel_id); } if *rejected_by_dest { log_trace!(self.logger, "Payment {} rejected by destination; not retrying", log_bytes!(payment_hash.0)); } else if payment_id.is_none() { log_trace!(self.logger, "Payment {} has no id; not retrying", log_bytes!(payment_hash.0)); - } else if let Some(params) = retry { - if self.retry_payment(payment_id.unwrap(), *payment_hash, params).is_ok() { - // We retried at least somewhat, don't provide the PaymentPathFailed event to the user. - return; - } - } else { + } else if retry.is_none() { log_trace!(self.logger, "Payment {} missing retry params; not retrying", log_bytes!(payment_hash.0)); + } else if self.retry_payment(payment_id.unwrap(), *payment_hash, retry.as_ref().unwrap()).is_ok() { + // We retried at least somewhat, don't provide the PaymentPathFailed event to the user. + return; } + if *all_paths_failed { self.payment_cache.lock().unwrap().remove(payment_hash); } }, Event::PaymentSent { payment_hash, .. } => { -- 2.39.5