Merge pull request #17 from TheBlueMatt/2017-04-channel-close

[rust-lightning] / src / ln / channel.rs

diff --git a/src/ln/channel.rs b/src/ln/channel.rs
index 08fa3efb1300e5cc07c1938f92d8f21a9e2e1db4..c9c9e41430d014ba6d6d62ee9d21c4a1a6bde230 100644 (file)
--- a/src/ln/channel.rs
+++ b/src/ln/channel.rs
@@ -1955,6 +1955,42 @@ impl Channel {
                        None => Ok(None)
                }
        }
+
+       /// Begins the shutdown process, getting a message for the remote peer and returning all
+       /// holding cell HTLCs for payment failure.
+       pub fn get_shutdown(&mut self) -> Result<(msgs::Shutdown, Vec<[u8; 32]>), HandleError> {
+               for htlc in self.pending_htlcs.iter() {
+                       if htlc.state == HTLCState::LocalAnnounced {
+                               return Err(HandleError{err: "Cannot begin shutdown with pending HTLCs, call send_commitment first", msg: None});
+                       }
+               }
+               if self.channel_state & BOTH_SIDES_SHUTDOWN_MASK != 0 {
+                       return Err(HandleError{err: "Shutdown already in progress", msg: None});
+               }
+               assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);
+
+               let our_closing_script = self.get_closing_scriptpubkey();
+
+               // From here on out, we may not fail!
+               if self.channel_state < ChannelState::FundingSent as u32 {
+                       self.channel_state = ChannelState::ShutdownComplete as u32;
+               } else {
+                       self.channel_state |= ChannelState::LocalShutdownSent as u32;
+               }
+
+               // We can't send our shutdown until we've committed all of our pending HTLCs, but the
+               // remote side is unlikely to accept any new HTLCs, so we go ahead and "free" any holding
+               // cell HTLCs and return them to fail the payment.
+               let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlcs.len());
+               for htlc in self.holding_cell_htlcs.drain(..) {
+                       dropped_outbound_htlcs.push(htlc.payment_hash);
+               }
+
+               Ok((msgs::Shutdown {
+                       channel_id: self.channel_id,
+                       scriptpubkey: our_closing_script,
+               }, dropped_outbound_htlcs))
+       }
 }
 
 #[cfg(test)]