use crypto::hkdf::{hkdf_extract,hkdf_expand};
use ln::msgs;
-use ln::msgs::{ErrorAction, HandleError, MsgEncodable};
+use ln::msgs::{ErrorAction, HandleError};
use ln::channelmonitor::ChannelMonitor;
use ln::channelmanager::{PendingHTLCStatus, HTLCSource, PendingForwardHTLCInfo, HTLCFailReason, HTLCFailureMsg};
use ln::chan_utils::{TxCreationKeys,HTLCOutputInCommitment,HTLC_SUCCESS_TX_WEIGHT,HTLC_TIMEOUT_TX_WEIGHT};
use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
use chain::transaction::OutPoint;
use util::{transaction_utils,rng};
+use util::ser::Writeable;
use util::sha2::Sha256;
use util::logger::Logger;
use util::errors::APIError;
}
const BOTH_SIDES_SHUTDOWN_MASK: u32 = (ChannelState::LocalShutdownSent as u32 | ChannelState::RemoteShutdownSent as u32);
+const INITIAL_COMMITMENT_NUMBER: u64 = (1 << 48) - 1;
+
// TODO: We should refactor this to be an Inbound/OutboundChannel until initial setup handshaking
// has been completed, and then turn into a Channel to get compiler-time enforcement of things like
// calling channel_id() before we're set up or things like get_outbound_funding_signed on an
// inbound channel.
-pub struct Channel {
+pub(super) struct Channel {
user_id: u64,
channel_id: [u8; 32],
channel_value_satoshis: channel_value_satoshis,
local_keys: chan_keys,
- cur_local_commitment_transaction_number: (1 << 48) - 1,
- cur_remote_commitment_transaction_number: (1 << 48) - 1,
+ cur_local_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
+ cur_remote_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
value_to_self_msat: channel_value_satoshis * 1000 - push_msat,
pending_inbound_htlcs: Vec::new(),
pending_outbound_htlcs: Vec::new(),
announce_publicly: their_announce,
local_keys: chan_keys,
- cur_local_commitment_transaction_number: (1 << 48) - 1,
- cur_remote_commitment_transaction_number: (1 << 48) - 1,
+ cur_local_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
+ cur_remote_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
value_to_self_msat: msg.push_msat,
pending_inbound_htlcs: Vec::new(),
pending_outbound_htlcs: Vec::new(),
/// which peer generated this transaction and "to whom" this transaction flows.
#[inline]
fn build_commitment_transaction(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool) -> (Transaction, Vec<HTLCOutputInCommitment>) {
- let obscured_commitment_transaction_number = self.get_commitment_transaction_number_obscure_factor() ^ (0xffffffffffff - commitment_number);
+ let obscured_commitment_transaction_number = self.get_commitment_transaction_number_obscure_factor() ^ (INITIAL_COMMITMENT_NUMBER - commitment_number);
let txins = {
let mut ins: Vec<TxIn> = Vec::new();
// channel.
return Err(HandleError{err: "Received funding_created after we got the channel!", action: Some(msgs::ErrorAction::SendErrorMessage {msg: msgs::ErrorMessage {channel_id: self.channel_id, data: "Received funding_created after we got the channel!".to_string()}})});
}
- if self.channel_monitor.get_min_seen_secret() != (1 << 48) || self.cur_remote_commitment_transaction_number != (1 << 48) - 1 || self.cur_local_commitment_transaction_number != (1 << 48) - 1 {
+ if self.channel_monitor.get_min_seen_secret() != (1 << 48) ||
+ self.cur_remote_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
+ self.cur_local_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
}
if self.channel_state != ChannelState::FundingCreated as u32 {
return Err(HandleError{err: "Received funding_signed in strange state!", action: None});
}
- if self.channel_monitor.get_min_seen_secret() != (1 << 48) || self.cur_remote_commitment_transaction_number != (1 << 48) - 2 || self.cur_local_commitment_transaction_number != (1 << 48) - 1 {
+ if self.channel_monitor.get_min_seen_secret() != (1 << 48) ||
+ self.cur_remote_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER - 1 ||
+ self.cur_local_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
}
self.channel_state = ChannelState::ChannelFunded as u32 | (self.channel_state & BOTH_SIDES_SHUTDOWN_MASK);
self.channel_update_count += 1;
} else if self.channel_state & (ChannelState::ChannelFunded as u32) != 0 &&
- self.cur_local_commitment_transaction_number == (1 << 48) - 2 &&
- self.cur_remote_commitment_transaction_number == (1 << 48) - 2 {
+ // Note that funding_signed/funding_created will have decremented both by 1!
+ self.cur_local_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 1 &&
+ self.cur_remote_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 1 {
if self.their_cur_commitment_point != Some(msg.next_per_commitment_point) {
return Err(HandleError{err: "Peer sent a reconnect funding_locked with a different point", action: None});
}
/// HTLCs that we intended to add but haven't as we were waiting on a remote revoke.
/// Returns the set of PendingHTLCStatuses from remote uncommitted HTLCs (which we're
/// implicitly dropping) and the payment_hashes of HTLCs we tried to add but are dropping.
- pub fn remove_uncommitted_htlcs(&mut self) -> Vec<(HTLCSource, [u8; 32])> {
+ /// No further message handling calls may be made until a channel_reestablish dance has
+ /// completed.
+ pub fn remove_uncommitted_htlcs_and_mark_paused(&mut self) -> Vec<(HTLCSource, [u8; 32])> {
let mut outbound_drops = Vec::new();
assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);
return outbound_drops;
}
+ let mut inbound_drop_count = 0;
self.pending_inbound_htlcs.retain(|htlc| {
match htlc.state {
InboundHTLCState::RemoteAnnounced => {
// They sent us an update_add_htlc but we never got the commitment_signed.
// We'll tell them what commitment_signed we're expecting next and they'll drop
// this HTLC accordingly
+ inbound_drop_count += 1;
false
},
InboundHTLCState::AwaitingRemoteRevokeToAnnounce|InboundHTLCState::AwaitingAnnouncedRemoteRevoke => {
&HTLCUpdateAwaitingACK::ClaimHTLC {..} | &HTLCUpdateAwaitingACK::FailHTLC {..} => true,
}
});
+ self.channel_state |= ChannelState::PeerDisconnected as u32;
+ log_debug!(self, "Peer disconnection resulted in {} remote-announced HTLC drops and {} waiting-to-locally-announced HTLC drops on channel {}", outbound_drops.len(), inbound_drop_count, log_bytes!(self.channel_id()));
outbound_drops
}
Ok(())
}
+ /// May panic if some calls other than message-handling calls (which will all Err immediately)
+ /// have been called between remove_uncommitted_htlcs_and_mark_paused and this call.
+ pub fn channel_reestablish(&mut self, msg: &msgs::ChannelReestablish) -> Result<(Option<msgs::FundingLocked>, Option<msgs::RevokeAndACK>, Option<msgs::CommitmentUpdate>, Option<ChannelMonitor>), HandleError> {
+ if self.channel_state & (ChannelState::PeerDisconnected as u32) == 0 {
+ return Err(HandleError{err: "Peer sent a loose channel_reestablish not after reconnect", action: Some(msgs::ErrorAction::SendErrorMessage{msg: msgs::ErrorMessage{data: "Peer sent a loose channel_reestablish not after reconnect".to_string(), channel_id: msg.channel_id}})});
+ }
+
+ if msg.next_local_commitment_number == 0 || msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER ||
+ msg.next_remote_commitment_number == 0 || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER {
+ return Err(HandleError{err: "Peer send garbage channel_reestablish", action: Some(msgs::ErrorAction::SendErrorMessage{msg: msgs::ErrorMessage{data: "Peer send garbage channel_reestablish".to_string(), channel_id: msg.channel_id}})});
+ }
+
+ // Go ahead and unmark PeerDisconnected as various calls we may make check for it (and all
+ // remaining cases either succeed or ErrorMessage-fail).
+ self.channel_state &= !(ChannelState::PeerDisconnected as u32);
+
+ let mut required_revoke = None;
+ if msg.next_remote_commitment_number == INITIAL_COMMITMENT_NUMBER - self.cur_local_commitment_transaction_number {
+ // Remote isn't waiting on any RevokeAndACK from us!
+ // Note that if we need to repeat our FundingLocked we'll do that in the next if block.
+ } else if msg.next_remote_commitment_number == (INITIAL_COMMITMENT_NUMBER - 1) - self.cur_local_commitment_transaction_number {
+ let next_per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &self.build_local_commitment_secret(self.cur_local_commitment_transaction_number));
+ let per_commitment_secret = chan_utils::build_commitment_secret(self.local_keys.commitment_seed, self.cur_local_commitment_transaction_number + 2);
+ required_revoke = Some(msgs::RevokeAndACK {
+ channel_id: self.channel_id,
+ per_commitment_secret,
+ next_per_commitment_point,
+ });
+ } else {
+ return Err(HandleError{err: "Peer attempted to reestablish channel with a very old local commitment transaction", action: Some(msgs::ErrorAction::SendErrorMessage{msg: msgs::ErrorMessage{data: "Peer attempted to reestablish channel with a very old remote commitment transaction".to_string(), channel_id: msg.channel_id}})});
+ }
+
+ if msg.next_local_commitment_number == INITIAL_COMMITMENT_NUMBER - self.cur_remote_commitment_transaction_number {
+ if msg.next_remote_commitment_number == INITIAL_COMMITMENT_NUMBER - self.cur_local_commitment_transaction_number {
+ log_debug!(self, "Reconnected channel {} with no lost commitment txn", log_bytes!(self.channel_id()));
+ if msg.next_local_commitment_number == 1 && msg.next_remote_commitment_number == 1 {
+ let next_per_commitment_secret = self.build_local_commitment_secret(self.cur_local_commitment_transaction_number);
+ let next_per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &next_per_commitment_secret);
+ return Ok((Some(msgs::FundingLocked {
+ channel_id: self.channel_id(),
+ next_per_commitment_point: next_per_commitment_point,
+ }), None, None, None));
+ }
+ }
+
+ if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 {
+ // We're up-to-date and not waiting on a remote revoke (if we are our
+ // channel_reestablish should result in them sending a revoke_and_ack), but we may
+ // have received some updates while we were disconnected. Free the holding cell
+ // now!
+ match self.free_holding_cell_htlcs() {
+ Err(e) => {
+ if let &Some(msgs::ErrorAction::DisconnectPeer{msg: Some(_)}) = &e.action {
+ } else if let &Some(msgs::ErrorAction::SendErrorMessage{msg: _}) = &e.action {
+ } else {
+ panic!("Got non-channel-failing result from free_holding_cell_htlcs");
+ }
+ return Err(e);
+ },
+ Ok(Some((commitment_update, channel_monitor))) => return Ok((None, required_revoke, Some(commitment_update), Some(channel_monitor))),
+ Ok(None) => return Ok((None, required_revoke, None, None)),
+ }
+ } else {
+ return Ok((None, required_revoke, None, None));
+ }
+ } else if msg.next_local_commitment_number == (INITIAL_COMMITMENT_NUMBER - 1) - self.cur_remote_commitment_transaction_number {
+ return Ok((None, required_revoke,
+ Some(msgs::CommitmentUpdate {
+ update_add_htlcs: Vec::new(),
+ update_fulfill_htlcs: Vec::new(),
+ update_fail_htlcs: Vec::new(),
+ update_fail_malformed_htlcs: Vec::new(),
+ commitment_signed: self.send_commitment_no_state_update().expect("It looks like we failed to re-generate a commitment_signed we had previously sent?").0,
+ }), None));
+ } else {
+ return Err(HandleError{err: "Peer attempted to reestablish channel with a very old remote commitment transaction", action: Some(msgs::ErrorAction::SendErrorMessage{msg: msgs::ErrorMessage{data: "Peer attempted to reestablish channel with a very old remote commitment transaction".to_string(), channel_id: msg.channel_id}})});
+ }
+ }
+
pub fn shutdown(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::Shutdown) -> Result<(Option<msgs::Shutdown>, Option<msgs::ClosingSigned>, Vec<(HTLCSource, [u8; 32])>), HandleError> {
if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
return Err(HandleError{err: "Peer sent shutdown when we needed a channel_reestablish", action: Some(msgs::ErrorAction::SendErrorMessage{msg: msgs::ErrorMessage{data: "Peer sent shutdown when we needed a channel_reestablish".to_string(), channel_id: msg.channel_id}})});
res as u32
}
+ /// Returns true if we've ever received a message from the remote end for this Channel
+ pub fn have_received_message(&self) -> bool {
+ self.channel_state > (ChannelState::OurInitSent as u32)
+ }
+
/// Returns true if this channel is fully established and not known to be closing.
/// Allowed in any state (including after shutdown)
pub fn is_usable(&self) -> bool {
panic!("Cannot generate an open_channel after we've moved forward");
}
- if self.cur_local_commitment_transaction_number != (1 << 48) - 1 {
+ if self.cur_local_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
panic!("Tried to send an open_channel for a channel that has already advanced");
}
if self.channel_state != (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32) {
panic!("Tried to send accept_channel after channel had moved forward");
}
- if self.cur_local_commitment_transaction_number != (1 << 48) - 1 {
+ if self.cur_local_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
panic!("Tried to send an accept_channel for a channel that has already advanced");
}
if self.channel_state != (ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32) {
panic!("Tried to get a funding_created messsage at a time other than immediately after initial handshake completion (or tried to get funding_created twice)");
}
- if self.channel_monitor.get_min_seen_secret() != (1 << 48) || self.cur_remote_commitment_transaction_number != (1 << 48) - 1 || self.cur_local_commitment_transaction_number != (1 << 48) - 1 {
+ if self.channel_monitor.get_min_seen_secret() != (1 << 48) ||
+ self.cur_remote_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
+ self.cur_local_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
}
Ok((msg, sig))
}
+ /// May panic if called on a channel that wasn't immediately-previously
+ /// self.remove_uncommitted_htlcs_and_mark_paused()'d
+ pub fn get_channel_reestablish(&self) -> msgs::ChannelReestablish {
+ assert_eq!(self.channel_state & ChannelState::PeerDisconnected as u32, ChannelState::PeerDisconnected as u32);
+ msgs::ChannelReestablish {
+ channel_id: self.channel_id(),
+ next_local_commitment_number: INITIAL_COMMITMENT_NUMBER - self.cur_local_commitment_transaction_number,
+ next_remote_commitment_number: INITIAL_COMMITMENT_NUMBER - self.cur_remote_commitment_transaction_number,
+ data_loss_protect: None,
+ }
+ }
+
// Send stuff to our remote peers:
projects / rust-lightning / blobdiff