+ // 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 self.context.channel_state != ChannelState::OurInitSent as u32 {
+ return Err(ChannelError::Close("Got an accept_channel message at a strange time".to_owned()));
+ }
+ if msg.dust_limit_satoshis > 21000000 * 100000000 {
+ return Err(ChannelError::Close(format!("Peer never wants payout outputs? dust_limit_satoshis was {}", msg.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.dust_limit_satoshis > self.context.holder_selected_channel_reserve_satoshis {
+ return Err(ChannelError::Close(format!("Dust limit ({}) is bigger than our channel reserve ({})", msg.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.htlc_minimum_msat >= full_channel_value_msat {
+ return Err(ChannelError::Close(format!("Minimum htlc value ({}) is full channel value ({})", msg.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.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.to_self_delay)));
+ }
+ if msg.max_accepted_htlcs < 1 {
+ return Err(ChannelError::Close("0 max_accepted_htlcs makes for a useless channel".to_owned()));
+ }
+ if msg.max_accepted_htlcs > MAX_HTLCS {
+ return Err(ChannelError::Close(format!("max_accepted_htlcs was {}. It must not be larger than {}", msg.max_accepted_htlcs, MAX_HTLCS)));
+ }
+
+ // Now check against optional parameters as set by config...
+ if msg.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.htlc_minimum_msat, peer_limits.max_htlc_minimum_msat)));
+ }
+ if msg.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.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.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.max_accepted_htlcs, peer_limits.min_max_accepted_htlcs)));
+ }
+ if msg.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
+ return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
+ }
+ if msg.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS {
+ return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS)));
+ }
+ if msg.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.minimum_depth)));
+ }
+
+ if let Some(ty) = &msg.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.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.dust_limit_satoshis;
+ self.context.counterparty_max_htlc_value_in_flight_msat = cmp::min(msg.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.htlc_minimum_msat;
+ self.context.counterparty_max_accepted_htlcs = msg.max_accepted_htlcs;
+
+ if peer_limits.trust_own_funding_0conf {
+ self.context.minimum_depth = Some(msg.minimum_depth);
+ } else {
+ self.context.minimum_depth = Some(cmp::max(1, msg.minimum_depth));
+ }
+
+ let counterparty_pubkeys = ChannelPublicKeys {
+ funding_pubkey: msg.funding_pubkey,
+ revocation_basepoint: msg.revocation_basepoint,
+ payment_point: msg.payment_point,
+ delayed_payment_basepoint: msg.delayed_payment_basepoint,
+ htlc_basepoint: msg.htlc_basepoint
+ };
+
+ self.context.channel_transaction_parameters.counterparty_parameters = Some(CounterpartyChannelTransactionParameters {
+ selected_contest_delay: msg.to_self_delay,
+ pubkeys: counterparty_pubkeys,
+ });
+
+ self.context.counterparty_cur_commitment_point = Some(msg.first_per_commitment_point);
+ self.context.counterparty_shutdown_scriptpubkey = counterparty_shutdown_scriptpubkey;
+
+ self.context.channel_state = ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32;
+ self.context.inbound_handshake_limits_override = None; // We're done enforcing limits on our peer's handshake now.
+
+ Ok(())
+ }
+}
+
+/// A not-yet-funded inbound (from counterparty) channel using V1 channel establishment.
+pub(super) struct InboundV1Channel<SP: Deref> where SP::Target: SignerProvider {
+ pub context: ChannelContext<SP>,
+ pub unfunded_context: UnfundedChannelContext,
+}
+
+impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
+ /// Creates a new channel from a remote sides' request for one.
+ /// Assumes chain_hash has already been checked and corresponds with what we expect!
+ pub fn new<ES: Deref, F: Deref, L: Deref>(
+ fee_estimator: &LowerBoundedFeeEstimator<F>, entropy_source: &ES, signer_provider: &SP,
+ counterparty_node_id: PublicKey, our_supported_features: &ChannelTypeFeatures,
+ their_features: &InitFeatures, msg: &msgs::OpenChannel, user_id: u128, config: &UserConfig,
+ current_chain_height: u32, logger: &L, is_0conf: bool,
+ ) -> Result<InboundV1Channel<SP>, ChannelError>
+ where ES::Target: EntropySource,
+ F::Target: FeeEstimator,
+ L::Target: Logger,
+ {
+ let announced_channel = if (msg.channel_flags & 1) == 1 { true } else { false };
+
+ // First check the channel type is known, failing before we do anything else if we don't
+ // support this channel type.
+ let channel_type = if let Some(channel_type) = &msg.channel_type {
+ if channel_type.supports_any_optional_bits() {
+ return Err(ChannelError::Close("Channel Type field contained optional bits - this is not allowed".to_owned()));
+ }
+
+ // We only support the channel types defined by the `ChannelManager` in
+ // `provided_channel_type_features`. The channel type must always support
+ // `static_remote_key`.
+ if !channel_type.requires_static_remote_key() {
+ return Err(ChannelError::Close("Channel Type was not understood - we require static remote key".to_owned()));
+ }
+ // Make sure we support all of the features behind the channel type.
+ if !channel_type.is_subset(our_supported_features) {
+ return Err(ChannelError::Close("Channel Type contains unsupported features".to_owned()));
+ }
+ if channel_type.requires_scid_privacy() && announced_channel {
+ return Err(ChannelError::Close("SCID Alias/Privacy Channel Type cannot be set on a public channel".to_owned()));
+ }
+ channel_type.clone()
+ } 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()));
+ }
+ channel_type
+ };
+
+ let channel_keys_id = signer_provider.generate_channel_keys_id(true, msg.funding_satoshis, user_id);
+ let holder_signer = signer_provider.derive_channel_signer(msg.funding_satoshis, channel_keys_id);
+ let pubkeys = holder_signer.pubkeys().clone();
+ let counterparty_pubkeys = ChannelPublicKeys {
+ funding_pubkey: msg.funding_pubkey,
+ revocation_basepoint: msg.revocation_basepoint,
+ payment_point: msg.payment_point,
+ delayed_payment_basepoint: msg.delayed_payment_basepoint,
+ htlc_basepoint: msg.htlc_basepoint
+ };