Move BREAKDOWN_TIMEOUT/MAX_LOCAL_BREAKDOWN_TIMEOUT in ChannelManager
[rust-lightning] / src / ln / channelmanager.rs
index 23d5eb21f75269fed9270c8c33913db9453b0d3c..10c5ce0a11cb2a8985f5e1e5d4f39a15e7b2e706 100644 (file)
@@ -12,11 +12,12 @@ use bitcoin::blockdata::block::BlockHeader;
 use bitcoin::blockdata::transaction::Transaction;
 use bitcoin::blockdata::constants::genesis_block;
 use bitcoin::network::constants::Network;
-use bitcoin::util::hash::{BitcoinHash, Sha256dHash};
+use bitcoin::util::hash::BitcoinHash;
 
 use bitcoin_hashes::{Hash, HashEngine};
 use bitcoin_hashes::hmac::{Hmac, HmacEngine};
 use bitcoin_hashes::sha256::Hash as Sha256;
+use bitcoin_hashes::sha256d::Hash as Sha256dHash;
 use bitcoin_hashes::cmp::fixed_time_eq;
 
 use secp256k1::key::{SecretKey,PublicKey};
@@ -27,14 +28,15 @@ use secp256k1;
 use chain::chaininterface::{BroadcasterInterface,ChainListener,ChainWatchInterface,FeeEstimator};
 use chain::transaction::OutPoint;
 use ln::channel::{Channel, ChannelError};
-use ln::channelmonitor::{ChannelMonitor, ChannelMonitorUpdateErr, ManyChannelMonitor, CLTV_CLAIM_BUFFER, HTLC_FAIL_TIMEOUT_BLOCKS, HTLC_FAIL_ANTI_REORG_DELAY};
+use ln::channelmonitor::{ChannelMonitor, ChannelMonitorUpdateErr, ManyChannelMonitor, CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS, ANTI_REORG_DELAY};
 use ln::router::Route;
 use ln::msgs;
+use ln::msgs::LocalFeatures;
 use ln::onion_utils;
 use ln::msgs::{ChannelMessageHandler, DecodeError, HandleError};
 use chain::keysinterface::KeysInterface;
 use util::config::UserConfig;
-use util::{byte_utils, events, rng};
+use util::{byte_utils, events};
 use util::ser::{Readable, ReadableArgs, Writeable, Writer};
 use util::chacha20::ChaCha20;
 use util::logger::Logger;
@@ -45,7 +47,7 @@ use std::collections::{HashMap, hash_map, HashSet};
 use std::io::Cursor;
 use std::sync::{Arc, Mutex, MutexGuard, RwLock};
 use std::sync::atomic::{AtomicUsize, Ordering};
-use std::time::{Instant,Duration};
+use std::time::Duration;
 
 // We hold various information about HTLC relay in the HTLC objects in Channel itself:
 //
@@ -212,11 +214,11 @@ impl MsgHandleErrInternal {
        }
 }
 
-/// We hold back HTLCs we intend to relay for a random interval in the range (this, 5*this). This
-/// provides some limited amount of privacy. Ideally this would range from somewhere like 1 second
-/// to 30 seconds, but people expect lightning to be, you know, kinda fast, sadly. We could
-/// probably increase this significantly.
-const MIN_HTLC_RELAY_HOLDING_CELL_MILLIS: u32 = 50;
+/// We hold back HTLCs we intend to relay for a random interval greater than this (see
+/// Event::PendingHTLCsForwardable for the API guidelines indicating how long should be waited).
+/// This provides some limited amount of privacy. Ideally this would range from somewhere like one
+/// second to 30 seconds, but people expect lightning to be, you know, kinda fast, sadly.
+const MIN_HTLC_RELAY_HOLDING_CELL_MILLIS: u64 = 100;
 
 pub(super) enum HTLCForwardInfo {
        AddHTLC {
@@ -246,7 +248,6 @@ pub(super) enum RAACommitmentOrder {
 pub(super) struct ChannelHolder {
        pub(super) by_id: HashMap<[u8; 32], Channel>,
        pub(super) short_to_id: HashMap<u64, [u8; 32]>,
-       pub(super) next_forward: Instant,
        /// short channel id -> forward infos. Key of 0 means payments received
        /// Note that while this is held in the same mutex as the channels themselves, no consistency
        /// guarantees are made about the existence of a channel with the short id here, nor the short
@@ -265,7 +266,6 @@ pub(super) struct ChannelHolder {
 pub(super) struct MutChannelHolder<'a> {
        pub(super) by_id: &'a mut HashMap<[u8; 32], Channel>,
        pub(super) short_to_id: &'a mut HashMap<u64, [u8; 32]>,
-       pub(super) next_forward: &'a mut Instant,
        pub(super) forward_htlcs: &'a mut HashMap<u64, Vec<HTLCForwardInfo>>,
        pub(super) claimable_htlcs: &'a mut HashMap<PaymentHash, Vec<(u64, HTLCPreviousHopData)>>,
        pub(super) pending_msg_events: &'a mut Vec<events::MessageSendEvent>,
@@ -275,7 +275,6 @@ impl ChannelHolder {
                MutChannelHolder {
                        by_id: &mut self.by_id,
                        short_to_id: &mut self.short_to_id,
-                       next_forward: &mut self.next_forward,
                        forward_htlcs: &mut self.forward_htlcs,
                        claimable_htlcs: &mut self.claimable_htlcs,
                        pending_msg_events: &mut self.pending_msg_events,
@@ -342,6 +341,12 @@ pub struct ChannelManager {
        logger: Arc<Logger>,
 }
 
+/// The amount of time we require our counterparty wait to claim their money (ie time between when
+/// we, or our watchtower, must check for them having broadcast a theft transaction).
+pub(crate) const BREAKDOWN_TIMEOUT: u16 = 6 * 24;
+/// The amount of time we're willing to wait to claim money back to us
+pub(crate) const MAX_LOCAL_BREAKDOWN_TIMEOUT: u16 = 6 * 24 * 7;
+
 /// The minimum number of blocks between an inbound HTLC's CLTV and the corresponding outbound
 /// HTLC's CLTV. This should always be a few blocks greater than channelmonitor::CLTV_CLAIM_BUFFER,
 /// ie the node we forwarded the payment on to should always have enough room to reliably time out
@@ -350,20 +355,21 @@ pub struct ChannelManager {
 const CLTV_EXPIRY_DELTA: u16 = 6 * 12; //TODO?
 pub(super) const CLTV_FAR_FAR_AWAY: u32 = 6 * 24 * 7; //TODO?
 
-// Check that our CLTV_EXPIRY is at least CLTV_CLAIM_BUFFER + 2*HTLC_FAIL_TIMEOUT_BLOCKS +
-// HTLC_FAIL_ANTI_REORG_DELAY, ie that if the next-hop peer fails the HTLC within
-// HTLC_FAIL_TIMEOUT_BLOCKS then we'll still have HTLC_FAIL_TIMEOUT_BLOCKS left to fail it
-// backwards ourselves before hitting the CLTV_CLAIM_BUFFER point and failing the channel
-// on-chain to time out the HTLC.
+// Check that our CLTV_EXPIRY is at least CLTV_CLAIM_BUFFER + ANTI_REORG_DELAY + LATENCY_GRACE_PERIOD_BLOCKS,
+// ie that if the next-hop peer fails the HTLC within
+// LATENCY_GRACE_PERIOD_BLOCKS then we'll still have CLTV_CLAIM_BUFFER left to timeout it onchain,
+// then waiting ANTI_REORG_DELAY to be reorg-safe on the outbound HLTC and
+// failing the corresponding htlc backward, and us now seeing the last block of ANTI_REORG_DELAY before
+// LATENCY_GRACE_PERIOD_BLOCKS.
 #[deny(const_err)]
 #[allow(dead_code)]
-const CHECK_CLTV_EXPIRY_SANITY: u32 = CLTV_EXPIRY_DELTA as u32 - 2*HTLC_FAIL_TIMEOUT_BLOCKS - CLTV_CLAIM_BUFFER - HTLC_FAIL_ANTI_REORG_DELAY;
+const CHECK_CLTV_EXPIRY_SANITY: u32 = CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - CLTV_CLAIM_BUFFER - ANTI_REORG_DELAY - LATENCY_GRACE_PERIOD_BLOCKS;
 
 // Check for ability of an attacker to make us fail on-chain by delaying inbound claim. See
 // ChannelMontior::would_broadcast_at_height for a description of why this is needed.
 #[deny(const_err)]
 #[allow(dead_code)]
-const CHECK_CLTV_EXPIRY_SANITY_2: u32 = CLTV_EXPIRY_DELTA as u32 - HTLC_FAIL_TIMEOUT_BLOCKS - 2*CLTV_CLAIM_BUFFER;
+const CHECK_CLTV_EXPIRY_SANITY_2: u32 = CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - 2*CLTV_CLAIM_BUFFER;
 
 macro_rules! secp_call {
        ( $res: expr, $err: expr ) => {
@@ -390,6 +396,20 @@ pub struct ChannelDetails {
        pub channel_value_satoshis: u64,
        /// The user_id passed in to create_channel, or 0 if the channel was inbound.
        pub user_id: u64,
+       /// The available outbound capacity for sending HTLCs to the remote peer. This does not include
+       /// any pending HTLCs which are not yet fully resolved (and, thus, who's balance is not
+       /// available for inclusion in new outbound HTLCs). This further does not include any pending
+       /// outgoing HTLCs which are awaiting some other resolution to be sent.
+       pub outbound_capacity_msat: u64,
+       /// The available inbound capacity for the remote peer to send HTLCs to us. This does not
+       /// include any pending HTLCs which are not yet fully resolved (and, thus, who's balance is not
+       /// available for inclusion in new inbound HTLCs).
+       /// Note that there are some corner cases not fully handled here, so the actual available
+       /// inbound capacity may be slightly higher than this.
+       pub inbound_capacity_msat: u64,
+       /// True if the channel is (a) confirmed and funding_locked messages have been exchanged, (b)
+       /// the peer is connected, and (c) no monitor update failure is pending resolution.
+       pub is_live: bool,
 }
 
 macro_rules! handle_error {
@@ -493,7 +513,7 @@ macro_rules! handle_monitor_err {
                                if !$resend_raa {
                                        debug_assert!($action_type == RAACommitmentOrder::CommitmentFirst || !$resend_commitment);
                                }
-                               $entry.get_mut().monitor_update_failed($action_type, $resend_raa, $resend_commitment, $failed_forwards, $failed_fails);
+                               $entry.get_mut().monitor_update_failed($resend_raa, $resend_commitment, $failed_forwards, $failed_fails);
                                Err(MsgHandleErrInternal::from_chan_no_close(ChannelError::Ignore("Failed to update ChannelMonitor"), *$entry.key()))
                        },
                }
@@ -548,7 +568,6 @@ impl ChannelManager {
                        channel_state: Mutex::new(ChannelHolder{
                                by_id: HashMap::new(),
                                short_to_id: HashMap::new(),
-                               next_forward: Instant::now(),
                                forward_htlcs: HashMap::new(),
                                claimable_htlcs: HashMap::new(),
                                pending_msg_events: Vec::new(),
@@ -612,12 +631,16 @@ impl ChannelManager {
                let channel_state = self.channel_state.lock().unwrap();
                let mut res = Vec::with_capacity(channel_state.by_id.len());
                for (channel_id, channel) in channel_state.by_id.iter() {
+                       let (inbound_capacity_msat, outbound_capacity_msat) = channel.get_inbound_outbound_available_balance_msat();
                        res.push(ChannelDetails {
                                channel_id: (*channel_id).clone(),
                                short_channel_id: channel.get_short_channel_id(),
                                remote_network_id: channel.get_their_node_id(),
                                channel_value_satoshis: channel.get_value_satoshis(),
+                               inbound_capacity_msat,
+                               outbound_capacity_msat,
                                user_id: channel.get_user_id(),
+                               is_live: channel.is_live(),
                        });
                }
                res
@@ -625,6 +648,9 @@ impl ChannelManager {
 
        /// Gets the list of usable channels, in random order. Useful as an argument to
        /// Router::get_route to ensure non-announced channels are used.
+       ///
+       /// These are guaranteed to have their is_live value set to true, see the documentation for
+       /// ChannelDetails::is_live for more info on exactly what the criteria are.
        pub fn list_usable_channels(&self) -> Vec<ChannelDetails> {
                let channel_state = self.channel_state.lock().unwrap();
                let mut res = Vec::with_capacity(channel_state.by_id.len());
@@ -633,12 +659,16 @@ impl ChannelManager {
                        // internal/external nomenclature, but that's ok cause that's probably what the user
                        // really wanted anyway.
                        if channel.is_live() {
+                               let (inbound_capacity_msat, outbound_capacity_msat) = channel.get_inbound_outbound_available_balance_msat();
                                res.push(ChannelDetails {
                                        channel_id: (*channel_id).clone(),
                                        short_channel_id: channel.get_short_channel_id(),
                                        remote_network_id: channel.get_their_node_id(),
                                        channel_value_satoshis: channel.get_value_satoshis(),
+                                       inbound_capacity_msat,
+                                       outbound_capacity_msat,
                                        user_id: channel.get_user_id(),
+                                       is_live: true,
                                });
                        }
                }
@@ -819,7 +849,7 @@ impl ChannelManager {
                let pending_forward_info = if next_hop_data.hmac == [0; 32] {
                                // OUR PAYMENT!
                                // final_expiry_too_soon
-                               if (msg.cltv_expiry as u64) < self.latest_block_height.load(Ordering::Acquire) as u64 + (CLTV_CLAIM_BUFFER + HTLC_FAIL_TIMEOUT_BLOCKS) as u64 {
+                               if (msg.cltv_expiry as u64) < self.latest_block_height.load(Ordering::Acquire) as u64 + (CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS) as u64 {
                                        return_err!("The final CLTV expiry is too soon to handle", 17, &[0;0]);
                                }
                                // final_incorrect_htlc_amount
@@ -911,8 +941,8 @@ impl ChannelManager {
                                                break Some(("Forwarding node has tampered with the intended HTLC values or origin node has an obsolete cltv_expiry_delta", 0x1000 | 13, Some(self.get_channel_update(chan).unwrap())));
                                        }
                                        let cur_height = self.latest_block_height.load(Ordering::Acquire) as u32 + 1;
-                                       // We want to have at least HTLC_FAIL_TIMEOUT_BLOCKS to fail prior to going on chain CLAIM_BUFFER blocks before expiration
-                                       if msg.cltv_expiry <= cur_height + CLTV_CLAIM_BUFFER + HTLC_FAIL_TIMEOUT_BLOCKS as u32 { // expiry_too_soon
+                                       // We want to have at least LATENCY_GRACE_PERIOD_BLOCKS to fail prior to going on chain CLAIM_BUFFER blocks before expiration
+                                       if msg.cltv_expiry <= cur_height + CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS as u32 { // expiry_too_soon
                                                break Some(("CLTV expiry is too close", 0x1000 | 14, Some(self.get_channel_update(chan).unwrap())));
                                        }
                                        if msg.cltv_expiry > cur_height + CLTV_FAR_FAR_AWAY as u32 { // expiry_too_far
@@ -964,7 +994,7 @@ impl ChannelManager {
                        excess_data: Vec::new(),
                };
 
-               let msg_hash = Sha256dHash::from_data(&unsigned.encode()[..]);
+               let msg_hash = Sha256dHash::hash(&unsigned.encode()[..]);
                let sig = self.secp_ctx.sign(&hash_to_message!(&msg_hash[..]), &self.our_network_key);
 
                Ok(msgs::ChannelUpdate {
@@ -1158,7 +1188,7 @@ impl ChannelManager {
                        Ok(res) => res,
                        Err(_) => return None, // Only in case of state precondition violations eg channel is closing
                };
-               let msghash = hash_to_message!(&Sha256dHash::from_data(&announcement.encode()[..])[..]);
+               let msghash = hash_to_message!(&Sha256dHash::hash(&announcement.encode()[..])[..]);
                let our_node_sig = self.secp_ctx.sign(&msghash, &self.our_network_key);
 
                Some(msgs::AnnouncementSignatures {
@@ -1183,10 +1213,6 @@ impl ChannelManager {
                        let mut channel_state_lock = self.channel_state.lock().unwrap();
                        let channel_state = channel_state_lock.borrow_parts();
 
-                       if cfg!(not(feature = "fuzztarget")) && Instant::now() < *channel_state.next_forward {
-                               return;
-                       }
-
                        for (short_chan_id, mut pending_forwards) in channel_state.forward_htlcs.drain() {
                                if short_chan_id != 0 {
                                        let forward_chan_id = match channel_state.short_to_id.get(&short_chan_id) {
@@ -1466,8 +1492,7 @@ impl ChannelManager {
 
                                let mut forward_event = None;
                                if channel_state_lock.forward_htlcs.is_empty() {
-                                       forward_event = Some(Instant::now() + Duration::from_millis(((rng::rand_f32() * 4.0 + 1.0) * MIN_HTLC_RELAY_HOLDING_CELL_MILLIS as f32) as u64));
-                                       channel_state_lock.next_forward = forward_event.unwrap();
+                                       forward_event = Some(Duration::from_millis(MIN_HTLC_RELAY_HOLDING_CELL_MILLIS));
                                }
                                match channel_state_lock.forward_htlcs.entry(short_channel_id) {
                                        hash_map::Entry::Occupied(mut entry) => {
@@ -1684,12 +1709,12 @@ impl ChannelManager {
                }
        }
 
-       fn internal_open_channel(&self, their_node_id: &PublicKey, msg: &msgs::OpenChannel) -> Result<(), MsgHandleErrInternal> {
+       fn internal_open_channel(&self, their_node_id: &PublicKey, their_local_features: LocalFeatures, msg: &msgs::OpenChannel) -> Result<(), MsgHandleErrInternal> {
                if msg.chain_hash != self.genesis_hash {
                        return Err(MsgHandleErrInternal::send_err_msg_no_close("Unknown genesis block hash", msg.temporary_channel_id.clone()));
                }
 
-               let channel = Channel::new_from_req(&*self.fee_estimator, &self.keys_manager, their_node_id.clone(), msg, 0, Arc::clone(&self.logger), &self.default_configuration)
+               let channel = Channel::new_from_req(&*self.fee_estimator, &self.keys_manager, their_node_id.clone(), their_local_features, msg, 0, Arc::clone(&self.logger), &self.default_configuration)
                        .map_err(|e| MsgHandleErrInternal::from_chan_no_close(e, msg.temporary_channel_id))?;
                let mut channel_state_lock = self.channel_state.lock().unwrap();
                let channel_state = channel_state_lock.borrow_parts();
@@ -1706,7 +1731,7 @@ impl ChannelManager {
                Ok(())
        }
 
-       fn internal_accept_channel(&self, their_node_id: &PublicKey, msg: &msgs::AcceptChannel) -> Result<(), MsgHandleErrInternal> {
+       fn internal_accept_channel(&self, their_node_id: &PublicKey, their_local_features: LocalFeatures, msg: &msgs::AcceptChannel) -> Result<(), MsgHandleErrInternal> {
                let (value, output_script, user_id) = {
                        let mut channel_lock = self.channel_state.lock().unwrap();
                        let channel_state = channel_lock.borrow_parts();
@@ -1716,7 +1741,7 @@ impl ChannelManager {
                                                //TODO: see issue #153, need a consistent behavior on obnoxious behavior from random node
                                                return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!", msg.temporary_channel_id));
                                        }
-                                       try_chan_entry!(self, chan.get_mut().accept_channel(&msg, &self.default_configuration), channel_state, chan);
+                                       try_chan_entry!(self, chan.get_mut().accept_channel(&msg, &self.default_configuration, their_local_features), channel_state, chan);
                                        (chan.get().get_value_satoshis(), chan.get().get_funding_redeemscript().to_v0_p2wsh(), chan.get().get_user_id())
                                },
                                //TODO: same as above
@@ -2076,8 +2101,7 @@ impl ChannelManager {
                        if !pending_forwards.is_empty() {
                                let mut channel_state = self.channel_state.lock().unwrap();
                                if channel_state.forward_htlcs.is_empty() {
-                                       forward_event = Some(Instant::now() + Duration::from_millis(((rng::rand_f32() * 4.0 + 1.0) * MIN_HTLC_RELAY_HOLDING_CELL_MILLIS as f32) as u64));
-                                       channel_state.next_forward = forward_event.unwrap();
+                                       forward_event = Some(Duration::from_millis(MIN_HTLC_RELAY_HOLDING_CELL_MILLIS))
                                }
                                for (forward_info, prev_htlc_id) in pending_forwards.drain(..) {
                                        match channel_state.forward_htlcs.entry(forward_info.short_channel_id) {
@@ -2182,7 +2206,7 @@ impl ChannelManager {
                                        try_chan_entry!(self, chan.get_mut().get_channel_announcement(our_node_id.clone(), self.genesis_hash.clone()), channel_state, chan);
 
                                let were_node_one = announcement.node_id_1 == our_node_id;
-                               let msghash = hash_to_message!(&Sha256dHash::from_data(&announcement.encode()[..])[..]);
+                               let msghash = hash_to_message!(&Sha256dHash::hash(&announcement.encode()[..])[..]);
                                if self.secp_ctx.verify(&msghash, &msg.node_signature, if were_node_one { &announcement.node_id_2 } else { &announcement.node_id_1 }).is_err() ||
                                                self.secp_ctx.verify(&msghash, &msg.bitcoin_signature, if were_node_one { &announcement.bitcoin_key_2 } else { &announcement.bitcoin_key_1 }).is_err() {
                                        try_chan_entry!(self, Err(ChannelError::Close("Bad announcement_signatures node_signature")), channel_state, chan);
@@ -2473,7 +2497,7 @@ impl ChainListener for ChannelManager {
        }
 
        /// We force-close the channel without letting our counterparty participate in the shutdown
-       fn block_disconnected(&self, header: &BlockHeader) {
+       fn block_disconnected(&self, header: &BlockHeader, _: u32) {
                let _ = self.total_consistency_lock.read().unwrap();
                let mut failed_channels = Vec::new();
                {
@@ -2508,14 +2532,14 @@ impl ChainListener for ChannelManager {
 
 impl ChannelMessageHandler for ChannelManager {
        //TODO: Handle errors and close channel (or so)
-       fn handle_open_channel(&self, their_node_id: &PublicKey, msg: &msgs::OpenChannel) -> Result<(), HandleError> {
+       fn handle_open_channel(&self, their_node_id: &PublicKey, their_local_features: LocalFeatures, msg: &msgs::OpenChannel) -> Result<(), HandleError> {
                let _ = self.total_consistency_lock.read().unwrap();
-               handle_error!(self, self.internal_open_channel(their_node_id, msg))
+               handle_error!(self, self.internal_open_channel(their_node_id, their_local_features, msg))
        }
 
-       fn handle_accept_channel(&self, their_node_id: &PublicKey, msg: &msgs::AcceptChannel) -> Result<(), HandleError> {
+       fn handle_accept_channel(&self, their_node_id: &PublicKey, their_local_features: LocalFeatures, msg: &msgs::AcceptChannel) -> Result<(), HandleError> {
                let _ = self.total_consistency_lock.read().unwrap();
-               handle_error!(self, self.internal_accept_channel(their_node_id, msg))
+               handle_error!(self, self.internal_accept_channel(their_node_id, their_local_features, msg))
        }
 
        fn handle_funding_created(&self, their_node_id: &PublicKey, msg: &msgs::FundingCreated) -> Result<(), HandleError> {
@@ -3086,7 +3110,6 @@ impl<'a, R : ::std::io::Read> ReadableArgs<R, ChannelManagerReadArgs<'a>> for (S
                        channel_state: Mutex::new(ChannelHolder {
                                by_id,
                                short_to_id,
-                               next_forward: Instant::now(),
                                forward_htlcs,
                                claimable_htlcs,
                                pending_msg_events: Vec::new(),