From: Duncan Dean Date: Thu, 13 Jun 2024 12:12:47 +0000 (+0200) Subject: Move accept_channel checks into `ChannelContext::do_accept_channel_checks` X-Git-Tag: v0.0.124-beta~79^2 X-Git-Url: http://git.bitcoin.ninja/?a=commitdiff_plain;h=0881b24895a6175632c59991c9e84b0d98ced810;p=rust-lightning Move accept_channel checks into `ChannelContext::do_accept_channel_checks` This is done ahead of getting the dual-funding implementation to reduce refactoring noise there. --- diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs index 57fbe5162..b8bccc63c 100644 --- a/lightning/src/ln/channel.rs +++ b/lightning/src/ln/channel.rs @@ -2146,6 +2146,143 @@ impl ChannelContext where SP::Target: SignerProvider { } } + /// Performs checks against necessary constraints after receiving either an `accept_channel` or + /// `accept_channel2` message. + pub fn do_accept_channel_checks( + &mut self, default_limits: &ChannelHandshakeLimits, their_features: &InitFeatures, + common_fields: &msgs::CommonAcceptChannelFields, channel_reserve_satoshis: u64, + ) -> Result<(), ChannelError> { + let peer_limits = if let Some(ref limits) = self.inbound_handshake_limits_override { limits } else { default_limits }; + + // Check sanity of message fields: + if !self.is_outbound() { + return Err(ChannelError::close("Got an accept_channel message from an inbound peer".to_owned())); + } + if !matches!(self.channel_state, ChannelState::NegotiatingFunding(flags) if flags == NegotiatingFundingFlags::OUR_INIT_SENT) { + return Err(ChannelError::close("Got an accept_channel message at a strange time".to_owned())); + } + if common_fields.dust_limit_satoshis > 21000000 * 100000000 { + return Err(ChannelError::close(format!("Peer never wants payout outputs? dust_limit_satoshis was {}", common_fields.dust_limit_satoshis))); + } + if channel_reserve_satoshis > self.channel_value_satoshis { + return Err(ChannelError::close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than ({})", channel_reserve_satoshis, self.channel_value_satoshis))); + } + if common_fields.dust_limit_satoshis > self.holder_selected_channel_reserve_satoshis { + return Err(ChannelError::close(format!("Dust limit ({}) is bigger than our channel reserve ({})", common_fields.dust_limit_satoshis, self.holder_selected_channel_reserve_satoshis))); + } + if channel_reserve_satoshis > self.channel_value_satoshis - self.holder_selected_channel_reserve_satoshis { + return Err(ChannelError::close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than channel value minus our reserve ({})", + channel_reserve_satoshis, self.channel_value_satoshis - self.holder_selected_channel_reserve_satoshis))); + } + let full_channel_value_msat = (self.channel_value_satoshis - channel_reserve_satoshis) * 1000; + if common_fields.htlc_minimum_msat >= full_channel_value_msat { + return Err(ChannelError::close(format!("Minimum htlc value ({}) is full channel value ({})", common_fields.htlc_minimum_msat, full_channel_value_msat))); + } + let max_delay_acceptable = u16::min(peer_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT); + if common_fields.to_self_delay > max_delay_acceptable { + return Err(ChannelError::close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_delay_acceptable, common_fields.to_self_delay))); + } + if common_fields.max_accepted_htlcs < 1 { + return Err(ChannelError::close("0 max_accepted_htlcs makes for a useless channel".to_owned())); + } + if common_fields.max_accepted_htlcs > MAX_HTLCS { + return Err(ChannelError::close(format!("max_accepted_htlcs was {}. It must not be larger than {}", common_fields.max_accepted_htlcs, MAX_HTLCS))); + } + + // Now check against optional parameters as set by config... + if common_fields.htlc_minimum_msat > peer_limits.max_htlc_minimum_msat { + return Err(ChannelError::close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", common_fields.htlc_minimum_msat, peer_limits.max_htlc_minimum_msat))); + } + if common_fields.max_htlc_value_in_flight_msat < peer_limits.min_max_htlc_value_in_flight_msat { + return Err(ChannelError::close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", common_fields.max_htlc_value_in_flight_msat, peer_limits.min_max_htlc_value_in_flight_msat))); + } + if channel_reserve_satoshis > peer_limits.max_channel_reserve_satoshis { + return Err(ChannelError::close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", channel_reserve_satoshis, peer_limits.max_channel_reserve_satoshis))); + } + if common_fields.max_accepted_htlcs < peer_limits.min_max_accepted_htlcs { + return Err(ChannelError::close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", common_fields.max_accepted_htlcs, peer_limits.min_max_accepted_htlcs))); + } + if common_fields.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS { + return Err(ChannelError::close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", common_fields.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS))); + } + if common_fields.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS { + return Err(ChannelError::close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", common_fields.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS))); + } + if common_fields.minimum_depth > peer_limits.max_minimum_depth { + return Err(ChannelError::close(format!("We consider the minimum depth to be unreasonably large. Expected minimum: ({}). Actual: ({})", peer_limits.max_minimum_depth, common_fields.minimum_depth))); + } + + if let Some(ty) = &common_fields.channel_type { + if *ty != self.channel_type { + return Err(ChannelError::close("Channel Type in accept_channel didn't match the one sent in open_channel.".to_owned())); + } + } else if their_features.supports_channel_type() { + // Assume they've accepted the channel type as they said they understand it. + } else { + let channel_type = ChannelTypeFeatures::from_init(&their_features); + if channel_type != ChannelTypeFeatures::only_static_remote_key() { + return Err(ChannelError::close("Only static_remote_key is supported for non-negotiated channel types".to_owned())); + } + self.channel_type = channel_type.clone(); + self.channel_transaction_parameters.channel_type_features = channel_type; + } + + let counterparty_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() { + match &common_fields.shutdown_scriptpubkey { + &Some(ref script) => { + // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything + if script.len() == 0 { + None + } else { + if !script::is_bolt2_compliant(&script, their_features) { + return Err(ChannelError::close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script))); + } + Some(script.clone()) + } + }, + // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel + &None => { + return Err(ChannelError::close("Peer is signaling upfront_shutdown but we don't get any script. Use 0-length script to opt-out".to_owned())); + } + } + } else { None }; + + self.counterparty_dust_limit_satoshis = common_fields.dust_limit_satoshis; + self.counterparty_max_htlc_value_in_flight_msat = cmp::min(common_fields.max_htlc_value_in_flight_msat, self.channel_value_satoshis * 1000); + self.counterparty_selected_channel_reserve_satoshis = Some(channel_reserve_satoshis); + self.counterparty_htlc_minimum_msat = common_fields.htlc_minimum_msat; + self.counterparty_max_accepted_htlcs = common_fields.max_accepted_htlcs; + + if peer_limits.trust_own_funding_0conf { + self.minimum_depth = Some(common_fields.minimum_depth); + } else { + self.minimum_depth = Some(cmp::max(1, common_fields.minimum_depth)); + } + + let counterparty_pubkeys = ChannelPublicKeys { + funding_pubkey: common_fields.funding_pubkey, + revocation_basepoint: RevocationBasepoint::from(common_fields.revocation_basepoint), + payment_point: common_fields.payment_basepoint, + delayed_payment_basepoint: DelayedPaymentBasepoint::from(common_fields.delayed_payment_basepoint), + htlc_basepoint: HtlcBasepoint::from(common_fields.htlc_basepoint) + }; + + self.channel_transaction_parameters.counterparty_parameters = Some(CounterpartyChannelTransactionParameters { + selected_contest_delay: common_fields.to_self_delay, + pubkeys: counterparty_pubkeys, + }); + + self.counterparty_cur_commitment_point = Some(common_fields.first_per_commitment_point); + self.counterparty_shutdown_scriptpubkey = counterparty_shutdown_scriptpubkey; + + self.channel_state = ChannelState::NegotiatingFunding( + NegotiatingFundingFlags::OUR_INIT_SENT | NegotiatingFundingFlags::THEIR_INIT_SENT + ); + self.inbound_handshake_limits_override = None; // We're done enforcing limits on our peer's handshake now. + + Ok(()) + } + /// Returns the block hash in which our funding transaction was confirmed. pub fn get_funding_tx_confirmed_in(&self) -> Option { self.funding_tx_confirmed_in @@ -7497,136 +7634,11 @@ impl OutboundV1Channel where SP::Target: SignerProvider { } // Message handlers - pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, default_limits: &ChannelHandshakeLimits, their_features: &InitFeatures) -> Result<(), ChannelError> { - let peer_limits = if let Some(ref limits) = self.context.inbound_handshake_limits_override { limits } else { default_limits }; - - // Check sanity of message fields: - if !self.context.is_outbound() { - return Err(ChannelError::close("Got an accept_channel message from an inbound peer".to_owned())); - } - if !matches!(self.context.channel_state, ChannelState::NegotiatingFunding(flags) if flags == NegotiatingFundingFlags::OUR_INIT_SENT) { - return Err(ChannelError::close("Got an accept_channel message at a strange time".to_owned())); - } - if msg.common_fields.dust_limit_satoshis > 21000000 * 100000000 { - return Err(ChannelError::close(format!("Peer never wants payout outputs? dust_limit_satoshis was {}", msg.common_fields.dust_limit_satoshis))); - } - if msg.channel_reserve_satoshis > self.context.channel_value_satoshis { - return Err(ChannelError::close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than ({})", msg.channel_reserve_satoshis, self.context.channel_value_satoshis))); - } - if msg.common_fields.dust_limit_satoshis > self.context.holder_selected_channel_reserve_satoshis { - return Err(ChannelError::close(format!("Dust limit ({}) is bigger than our channel reserve ({})", msg.common_fields.dust_limit_satoshis, self.context.holder_selected_channel_reserve_satoshis))); - } - if msg.channel_reserve_satoshis > self.context.channel_value_satoshis - self.context.holder_selected_channel_reserve_satoshis { - return Err(ChannelError::close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than channel value minus our reserve ({})", - msg.channel_reserve_satoshis, self.context.channel_value_satoshis - self.context.holder_selected_channel_reserve_satoshis))); - } - let full_channel_value_msat = (self.context.channel_value_satoshis - msg.channel_reserve_satoshis) * 1000; - if msg.common_fields.htlc_minimum_msat >= full_channel_value_msat { - return Err(ChannelError::close(format!("Minimum htlc value ({}) is full channel value ({})", msg.common_fields.htlc_minimum_msat, full_channel_value_msat))); - } - let max_delay_acceptable = u16::min(peer_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT); - if msg.common_fields.to_self_delay > max_delay_acceptable { - return Err(ChannelError::close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_delay_acceptable, msg.common_fields.to_self_delay))); - } - if msg.common_fields.max_accepted_htlcs < 1 { - return Err(ChannelError::close("0 max_accepted_htlcs makes for a useless channel".to_owned())); - } - if msg.common_fields.max_accepted_htlcs > MAX_HTLCS { - return Err(ChannelError::close(format!("max_accepted_htlcs was {}. It must not be larger than {}", msg.common_fields.max_accepted_htlcs, MAX_HTLCS))); - } - - // Now check against optional parameters as set by config... - if msg.common_fields.htlc_minimum_msat > peer_limits.max_htlc_minimum_msat { - return Err(ChannelError::close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.common_fields.htlc_minimum_msat, peer_limits.max_htlc_minimum_msat))); - } - if msg.common_fields.max_htlc_value_in_flight_msat < peer_limits.min_max_htlc_value_in_flight_msat { - return Err(ChannelError::close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.common_fields.max_htlc_value_in_flight_msat, peer_limits.min_max_htlc_value_in_flight_msat))); - } - if msg.channel_reserve_satoshis > peer_limits.max_channel_reserve_satoshis { - return Err(ChannelError::close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, peer_limits.max_channel_reserve_satoshis))); - } - if msg.common_fields.max_accepted_htlcs < peer_limits.min_max_accepted_htlcs { - return Err(ChannelError::close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.common_fields.max_accepted_htlcs, peer_limits.min_max_accepted_htlcs))); - } - if msg.common_fields.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS { - return Err(ChannelError::close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.common_fields.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS))); - } - if msg.common_fields.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS { - return Err(ChannelError::close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.common_fields.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS))); - } - if msg.common_fields.minimum_depth > peer_limits.max_minimum_depth { - return Err(ChannelError::close(format!("We consider the minimum depth to be unreasonably large. Expected minimum: ({}). Actual: ({})", peer_limits.max_minimum_depth, msg.common_fields.minimum_depth))); - } - - if let Some(ty) = &msg.common_fields.channel_type { - if *ty != self.context.channel_type { - return Err(ChannelError::close("Channel Type in accept_channel didn't match the one sent in open_channel.".to_owned())); - } - } else if their_features.supports_channel_type() { - // Assume they've accepted the channel type as they said they understand it. - } else { - let channel_type = ChannelTypeFeatures::from_init(&their_features); - if channel_type != ChannelTypeFeatures::only_static_remote_key() { - return Err(ChannelError::close("Only static_remote_key is supported for non-negotiated channel types".to_owned())); - } - self.context.channel_type = channel_type.clone(); - self.context.channel_transaction_parameters.channel_type_features = channel_type; - } - - let counterparty_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() { - match &msg.common_fields.shutdown_scriptpubkey { - &Some(ref script) => { - // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything - if script.len() == 0 { - None - } else { - if !script::is_bolt2_compliant(&script, their_features) { - return Err(ChannelError::close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script))); - } - Some(script.clone()) - } - }, - // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel - &None => { - return Err(ChannelError::close("Peer is signaling upfront_shutdown but we don't get any script. Use 0-length script to opt-out".to_owned())); - } - } - } else { None }; - - self.context.counterparty_dust_limit_satoshis = msg.common_fields.dust_limit_satoshis; - self.context.counterparty_max_htlc_value_in_flight_msat = cmp::min(msg.common_fields.max_htlc_value_in_flight_msat, self.context.channel_value_satoshis * 1000); - self.context.counterparty_selected_channel_reserve_satoshis = Some(msg.channel_reserve_satoshis); - self.context.counterparty_htlc_minimum_msat = msg.common_fields.htlc_minimum_msat; - self.context.counterparty_max_accepted_htlcs = msg.common_fields.max_accepted_htlcs; - - if peer_limits.trust_own_funding_0conf { - self.context.minimum_depth = Some(msg.common_fields.minimum_depth); - } else { - self.context.minimum_depth = Some(cmp::max(1, msg.common_fields.minimum_depth)); - } - - let counterparty_pubkeys = ChannelPublicKeys { - funding_pubkey: msg.common_fields.funding_pubkey, - revocation_basepoint: RevocationBasepoint::from(msg.common_fields.revocation_basepoint), - payment_point: msg.common_fields.payment_basepoint, - delayed_payment_basepoint: DelayedPaymentBasepoint::from(msg.common_fields.delayed_payment_basepoint), - htlc_basepoint: HtlcBasepoint::from(msg.common_fields.htlc_basepoint) - }; - - self.context.channel_transaction_parameters.counterparty_parameters = Some(CounterpartyChannelTransactionParameters { - selected_contest_delay: msg.common_fields.to_self_delay, - pubkeys: counterparty_pubkeys, - }); - - self.context.counterparty_cur_commitment_point = Some(msg.common_fields.first_per_commitment_point); - self.context.counterparty_shutdown_scriptpubkey = counterparty_shutdown_scriptpubkey; - - self.context.channel_state = ChannelState::NegotiatingFunding( - NegotiatingFundingFlags::OUR_INIT_SENT | NegotiatingFundingFlags::THEIR_INIT_SENT - ); - self.context.inbound_handshake_limits_override = None; // We're done enforcing limits on our peer's handshake now. - - Ok(()) + pub fn accept_channel( + &mut self, msg: &msgs::AcceptChannel, default_limits: &ChannelHandshakeLimits, + their_features: &InitFeatures + ) -> Result<(), ChannelError> { + self.context.do_accept_channel_checks(default_limits, their_features, &msg.common_fields, msg.channel_reserve_satoshis) } /// Handles a funding_signed message from the remote end.