X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=src%2Fln%2Fchannel.rs;h=68a23dc67b9348dac07e795e5b8c9d50555470ed;hb=e7526112470409c921e08da91dee8eeeaf0b0563;hp=978be08dc217e4284ef576473a7538fd677ce549;hpb=ca6b44b8cce864bac61a38a967284e8128836cbd;p=rust-lightning diff --git a/src/ln/channel.rs b/src/ln/channel.rs index 978be08d..68a23dc6 100644 --- a/src/ln/channel.rs +++ b/src/ln/channel.rs @@ -14,7 +14,7 @@ use crypto::digest::Digest; use crypto::hkdf::{hkdf_extract,hkdf_expand}; use ln::msgs; -use ln::msgs::{HandleError, MsgEncodable}; +use ln::msgs::{ErrorAction, HandleError, MsgEncodable}; use ln::channelmonitor::ChannelMonitor; use ln::channelmanager::{PendingForwardHTLCInfo, HTLCFailReason}; use ln::chan_utils::{TxCreationKeys,HTLCOutputInCommitment,HTLC_SUCCESS_TX_WEIGHT,HTLC_TIMEOUT_TX_WEIGHT}; @@ -24,6 +24,7 @@ use chain::transaction::OutPoint; use util::{transaction_utils,rng}; use util::sha2::Sha256; +use std; use std::default::Default; use std::{cmp,mem}; use std::time::Instant; @@ -135,7 +136,7 @@ enum HTLCState { /// anyway). LocalRemoved, /// Removed by us, sent a new commitment_signed and got a revoke_and_ack. Just waiting on an - /// updated local commitment transaction. + /// updated local commitment transaction. Implies local_removed_fulfilled. LocalRemovedAwaitingCommitment, } @@ -270,7 +271,7 @@ pub struct Channel { /// to detect unconfirmation after a serialize-unserialize roudtrip where we may not see a full /// series of block_connected/block_disconnected calls. Obviously this is not a guarantee as we /// could miss the funding_tx_confirmed_in block as well, but it serves as a useful fallback. - funding_tx_confirmed_in: Sha256dHash, + funding_tx_confirmed_in: Option, short_channel_id: Option, /// Used to deduplicate block_connected callbacks last_block_connected: Sha256dHash, @@ -400,7 +401,7 @@ impl Channel { last_sent_closing_fee: None, - funding_tx_confirmed_in: Default::default(), + funding_tx_confirmed_in: None, short_channel_id: None, last_block_connected: Default::default(), funding_tx_confirmations: 0, @@ -518,7 +519,7 @@ impl Channel { last_sent_closing_fee: None, - funding_tx_confirmed_in: Default::default(), + funding_tx_confirmed_in: None, short_channel_id: None, last_block_connected: Default::default(), funding_tx_confirmations: 0, @@ -662,7 +663,7 @@ impl Channel { } else { match htlc.state { HTLCState::AwaitingRemoteRevokeToRemove|HTLCState::AwaitingRemovedRemoteRevoke => { - if generated_by_local && htlc.fail_reason.is_none() { + if htlc.fail_reason.is_none() { value_to_self_msat_offset -= htlc.amount_msat as i64; } }, @@ -677,6 +678,7 @@ impl Channel { } }, HTLCState::LocalRemovedAwaitingCommitment => { + assert!(htlc.local_removed_fulfilled); value_to_self_msat_offset += htlc.amount_msat as i64; }, _ => {}, @@ -927,7 +929,7 @@ impl Channel { Ok(our_sig) } - pub fn get_update_fulfill_htlc(&mut self, payment_preimage_arg: [u8; 32]) -> Result, HandleError> { + fn get_update_fulfill_htlc(&mut self, payment_preimage_arg: [u8; 32]) -> Result<(Option, Option), HandleError> { // Either ChannelFunded got set (which means it wont bet unset) or there is no way any // caller thought we could have something claimed (cause we wouldn't have accepted in an // incoming HTLC anyway). If we got to ShutdownComplete, callers aren't allowed to call us, @@ -942,13 +944,31 @@ impl Channel { let mut payment_hash_calc = [0; 32]; sha.result(&mut payment_hash_calc); + let mut pending_idx = std::usize::MAX; + for (idx, htlc) in self.pending_htlcs.iter().enumerate() { + if !htlc.outbound && htlc.payment_hash == payment_hash_calc { + if pending_idx != std::usize::MAX { + panic!("Duplicate HTLC payment_hash, you probably re-used payment preimages, NEVER DO THIS!"); + } + pending_idx = idx; + } + } + if pending_idx == std::usize::MAX { + return Err(HandleError{err: "Unable to find a pending HTLC which matched the given payment preimage", action: None}); + } + // Now update local state: + // + // We have to put the payment_preimage in the channel_monitor right away here to ensure we + // can claim it even if the channel hits the chain before we see their next commitment. + self.channel_monitor.provide_payment_preimage(&payment_hash_calc, &payment_preimage_arg); + if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == (ChannelState::AwaitingRemoteRevoke as u32) { for pending_update in self.holding_cell_htlc_updates.iter() { match pending_update { &HTLCUpdateAwaitingACK::ClaimHTLC { ref payment_preimage, .. } => { if payment_preimage_arg == *payment_preimage { - return Ok(None); + return Ok((None, None)); } }, &HTLCUpdateAwaitingACK::FailHTLC { ref payment_hash, .. } => { @@ -962,49 +982,39 @@ impl Channel { self.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::ClaimHTLC { payment_preimage: payment_preimage_arg, payment_hash: payment_hash_calc, }); - return Ok(None); - } - - let mut htlc_id = 0; - let mut htlc_amount_msat = 0; - for htlc in self.pending_htlcs.iter_mut() { - if !htlc.outbound && htlc.payment_hash == payment_hash_calc { - if htlc_id != 0 { - panic!("Duplicate HTLC payment_hash, you probably re-used payment preimages, NEVER DO THIS!"); - } - htlc_id = htlc.htlc_id; - htlc_amount_msat += htlc.amount_msat; - if htlc.state == HTLCState::Committed { - htlc.state = HTLCState::LocalRemoved; - htlc.local_removed_fulfilled = true; - } else if htlc.state == HTLCState::RemoteAnnounced { - panic!("Somehow forwarded HTLC prior to remote revocation!"); - } else if htlc.state == HTLCState::LocalRemoved || htlc.state == HTLCState::LocalRemovedAwaitingCommitment { - return Err(HandleError{err: "Unable to find a pending HTLC which matched the given payment preimage", action: None}); - } else { - panic!("Have an inbound HTLC when not awaiting remote revoke that had a garbage state"); - } + return Ok((None, Some(self.channel_monitor.clone()))); + } + + let htlc_id = { + let htlc = &mut self.pending_htlcs[pending_idx]; + if htlc.state == HTLCState::Committed { + htlc.state = HTLCState::LocalRemoved; + htlc.local_removed_fulfilled = true; + } else if htlc.state == HTLCState::RemoteAnnounced { + panic!("Somehow forwarded HTLC prior to remote revocation!"); + } else if htlc.state == HTLCState::LocalRemoved || htlc.state == HTLCState::LocalRemovedAwaitingCommitment { + return Err(HandleError{err: "Unable to find a pending HTLC which matched the given payment preimage", action: None}); + } else { + panic!("Have an inbound HTLC when not awaiting remote revoke that had a garbage state"); } - } - if htlc_amount_msat == 0 { - return Err(HandleError{err: "Unable to find a pending HTLC which matched the given payment preimage", action: None}); - } - self.channel_monitor.provide_payment_preimage(&payment_hash_calc, &payment_preimage_arg); + htlc.htlc_id + }; - Ok(Some((msgs::UpdateFulfillHTLC { + Ok((Some(msgs::UpdateFulfillHTLC { channel_id: self.channel_id(), htlc_id: htlc_id, payment_preimage: payment_preimage_arg, - }, self.channel_monitor.clone()))) + }), Some(self.channel_monitor.clone()))) } - pub fn get_update_fulfill_htlc_and_commit(&mut self, payment_preimage: [u8; 32]) -> Result, HandleError> { + pub fn get_update_fulfill_htlc_and_commit(&mut self, payment_preimage: [u8; 32]) -> Result<(Option<(msgs::UpdateFulfillHTLC, msgs::CommitmentSigned)>, Option), HandleError> { match self.get_update_fulfill_htlc(payment_preimage)? { - Some(update_fulfill_htlc) => { + (Some(update_fulfill_htlc), _) => { let (commitment, monitor_update) = self.send_commitment_no_status_check()?; - Ok(Some((update_fulfill_htlc.0, commitment, monitor_update))) + Ok((Some((update_fulfill_htlc, commitment)), Some(monitor_update))) }, - None => Ok(None) + (None, Some(channel_monitor)) => Ok((None, Some(channel_monitor))), + (None, None) => Ok((None, None)) } } @@ -1347,7 +1357,7 @@ impl Channel { Err(HandleError{err: "Remote tried to fulfill/fail an HTLC we couldn't find", action: None}) } - pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result { + pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<(), HandleError> { if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) { return Err(HandleError{err: "Got add HTLC message when channel was not in an operational state", action: None}); } @@ -1357,9 +1367,8 @@ impl Channel { let mut payment_hash = [0; 32]; sha.result(&mut payment_hash); - self.channel_monitor.provide_payment_preimage(&payment_hash, &msg.payment_preimage); self.mark_outbound_htlc_removed(msg.htlc_id, Some(payment_hash), None)?; - Ok(self.channel_monitor.clone()) + Ok(()) } pub fn update_fail_htlc(&mut self, msg: &msgs::UpdateFailHTLC, fail_reason: HTLCFailReason) -> Result<[u8; 32], HandleError> { @@ -1491,7 +1500,7 @@ impl Channel { }, &HTLCUpdateAwaitingACK::ClaimHTLC { payment_preimage, .. } => { match self.get_update_fulfill_htlc(payment_preimage) { - Ok(update_fulfill_msg_option) => update_fulfill_htlcs.push(update_fulfill_msg_option.unwrap().0), + Ok(update_fulfill_msg_option) => update_fulfill_htlcs.push(update_fulfill_msg_option.0.unwrap()), Err(e) => { err = Some(e); } @@ -1818,6 +1827,7 @@ impl Channel { self.user_id } + /// May only be called after funding has been initiated (ie is_funding_initiated() is true) pub fn channel_monitor(&self) -> ChannelMonitor { if self.channel_state < ChannelState::FundingCreated as u32 { panic!("Can't get a channel monitor until funding has been created"); @@ -1827,6 +1837,7 @@ impl Channel { /// Guaranteed to be Some after both FundingLocked messages have been exchanged (and, thus, /// is_usable() returns true). + /// Allowed in any state (including after shutdown) pub fn get_short_channel_id(&self) -> Option { self.short_channel_id } @@ -1837,10 +1848,12 @@ impl Channel { self.channel_monitor.get_funding_txo() } + /// Allowed in any state (including after shutdown) pub fn get_their_node_id(&self) -> PublicKey { self.their_node_id } + /// Allowed in any state (including after shutdown) pub fn get_our_htlc_minimum_msat(&self) -> u64 { self.our_htlc_minimum_msat } @@ -1849,6 +1862,7 @@ impl Channel { self.channel_value_satoshis } + /// Allowed in any state (including after shutdown) pub fn get_channel_update_count(&self) -> u32 { self.channel_update_count } @@ -1858,6 +1872,7 @@ impl Channel { } /// Gets the fee we'd want to charge for adding an HTLC output to this Channel + /// Allowed in any state (including after shutdown) pub fn get_our_fee_base_msat(&self, fee_estimator: &FeeEstimator) -> u32 { // For lack of a better metric, we calculate what it would cost to consolidate the new HTLC // output value back into a transaction with the regular channel output: @@ -1877,6 +1892,7 @@ impl Channel { } /// 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 { let mask = ChannelState::ChannelFunded as u32 | BOTH_SIDES_SHUTDOWN_MASK; (self.channel_state & mask) == (ChannelState::ChannelFunded as u32) @@ -1884,10 +1900,16 @@ impl Channel { /// Returns true if this channel is currently available for use. This is a superset of /// is_usable() and considers things like the channel being temporarily disabled. + /// Allowed in any state (including after shutdown) pub fn is_live(&self) -> bool { self.is_usable() } + /// Returns true if funding_created was sent/received. + pub fn is_funding_initiated(&self) -> bool { + self.channel_state >= ChannelState::FundingCreated as u32 + } + /// Returns true if this channel is fully shut down. True here implies that no further actions /// may/will be taken on this channel, and thus this object should be freed. Any future changes /// will be handled appropriately by the chain monitor. @@ -1901,34 +1923,48 @@ impl Channel { /// Called by channelmanager based on chain blocks being connected. /// Note that we only need to use this to detect funding_signed, anything else is handled by /// the channel_monitor. - pub fn block_connected(&mut self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[u32]) -> Option { + /// In case of Err, the channel may have been closed, at which point the standard requirements + /// apply - no calls may be made except those explicitly stated to be allowed post-shutdown. + /// Only returns an ErrorAction of DisconnectPeer, if Err. + pub fn block_connected(&mut self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[u32]) -> Result, HandleError> { let non_shutdown_state = self.channel_state & (!BOTH_SIDES_SHUTDOWN_MASK); if self.funding_tx_confirmations > 0 { if header.bitcoin_hash() != self.last_block_connected { self.last_block_connected = header.bitcoin_hash(); self.funding_tx_confirmations += 1; if self.funding_tx_confirmations == CONF_TARGET as u64 { - if non_shutdown_state == ChannelState::FundingSent as u32 { + let need_commitment_update = if non_shutdown_state == ChannelState::FundingSent as u32 { self.channel_state |= ChannelState::OurFundingLocked as u32; + true } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::TheirFundingLocked as u32) { self.channel_state = ChannelState::ChannelFunded as u32 | (self.channel_state & BOTH_SIDES_SHUTDOWN_MASK); self.channel_update_count += 1; - //TODO: Something about a state where we "lost confirmation" + true + } else if self.channel_state == (ChannelState::FundingSent as u32 | ChannelState::OurFundingLocked as u32) { + // We got a reorg but not enough to trigger a force close, just update + // funding_tx_confirmed_in and return. + false } else if self.channel_state < ChannelState::ChannelFunded as u32 { - panic!("Started confirming a channel in a state pre-FundingSent?"); - } - self.funding_tx_confirmed_in = header.bitcoin_hash(); + panic!("Started confirming a channel in a state pre-FundingSent?: {}", self.channel_state); + } else { + // We got a reorg but not enough to trigger a force close, just update + // funding_tx_confirmed_in and return. + false + }; + self.funding_tx_confirmed_in = Some(header.bitcoin_hash()); //TODO: Note that this must be a duplicate of the previous commitment point they sent us, //as otherwise we will have a commitment transaction that they can't revoke (well, kinda, //they can by sending two revoke_and_acks back-to-back, but not really). This appears to be //a protocol oversight, but I assume I'm just missing something. - 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).unwrap(); - return Some(msgs::FundingLocked { - channel_id: self.channel_id, - next_per_commitment_point: next_per_commitment_point, - }); + if need_commitment_update { + 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).unwrap(); + return Ok(Some(msgs::FundingLocked { + channel_id: self.channel_id, + next_per_commitment_point: next_per_commitment_point, + })); + } } } } @@ -1940,6 +1976,7 @@ impl Channel { tx.output[txo_idx].value != self.channel_value_satoshis { self.channel_state = ChannelState::ShutdownComplete as u32; self.channel_update_count += 1; + return Err(HandleError{err: "funding tx had wrong script/value", action: Some(ErrorAction::DisconnectPeer{msg: None})}); } else { self.funding_tx_confirmations = 1; self.short_channel_id = Some(((height as u64) << (5*8)) | @@ -1949,7 +1986,7 @@ impl Channel { } } } - None + Ok(None) } /// Called by channelmanager based on chain blocks being disconnected. @@ -1962,7 +1999,7 @@ impl Channel { return true; } } - if header.bitcoin_hash() == self.funding_tx_confirmed_in { + if Some(header.bitcoin_hash()) == self.funding_tx_confirmed_in { self.funding_tx_confirmations = CONF_TARGET as u64 - 1; } false @@ -2323,14 +2360,39 @@ impl Channel { } /// Gets the latest commitment transaction and any dependant transactions for relay (forcing - /// shutdown of this channel - no more calls into this Channel may be made afterwards. - pub fn force_shutdown(&mut self) -> Vec { + /// shutdown of this channel - no more calls into this Channel may be made afterwards except + /// those explicitly stated to be allowed after shutdown completes, eg some simple getters). + /// Also returns the list of payment_hashes for channels which we can safely fail backwards + /// immediately (others we will have to allow to time out). + pub fn force_shutdown(&mut self) -> (Vec, Vec<[u8; 32]>) { assert!(self.channel_state != ChannelState::ShutdownComplete as u32); + + // We go ahead and "free" any holding cell HTLCs or HTLCs we haven't yet committed to and + // return them to fail the payment. + let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len()); + for htlc_update in self.holding_cell_htlc_updates.drain(..) { + match htlc_update { + HTLCUpdateAwaitingACK::AddHTLC { payment_hash, .. } => { + dropped_outbound_htlcs.push(payment_hash); + }, + _ => {} + } + } + + for htlc in self.pending_htlcs.drain(..) { + if htlc.state == HTLCState::LocalAnnounced { + dropped_outbound_htlcs.push(htlc.payment_hash); + } + //TODO: Do something with the remaining HTLCs + //(we need to have the ChannelManager monitor them so we can claim the inbound HTLCs + //which correspond) + } + self.channel_state = ChannelState::ShutdownComplete as u32; self.channel_update_count += 1; let mut res = Vec::new(); mem::swap(&mut res, &mut self.last_local_commitment_txn); - res + (res, dropped_outbound_htlcs) } }