X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=src%2Fln%2Fpeer_handler.rs;h=76cc35f64c550b9b401faab6272a9d163383e821;hb=99e01b2a6470c0b3f22b3d58d23e7f3b71be91f1;hp=01416568b468f404e898cd9b718f17d539835543;hpb=8a7dd2f9b8c09aab9f89df3a04e8535109c263bc;p=rust-lightning diff --git a/src/ln/peer_handler.rs b/src/ln/peer_handler.rs index 01416568..76cc35f6 100644 --- a/src/ln/peer_handler.rs +++ b/src/ln/peer_handler.rs @@ -1,3 +1,11 @@ +//! Top level peer message handling and socket handling logic lives here. +//! +//! Instead of actually servicing sockets ourselves we require that you implement the +//! SocketDescriptor interface and use that to receive actions which you should perform on the +//! socket, and call into PeerManager with bytes read from the socket. The PeerManager will then +//! call into the provided message handlers (probably a ChannelManager and Router) with messages +//! they should handle, and encoding/sending response messages. + use secp256k1::key::{SecretKey,PublicKey}; use ln::msgs; @@ -12,15 +20,22 @@ use std::sync::{Arc, Mutex}; use std::sync::atomic::{AtomicUsize, Ordering}; use std::{cmp,error,mem,hash,fmt}; +/// Provides references to trait impls which handle different types of messages. pub struct MessageHandler { + /// A message handler which handles messages specific to channels. Usually this is just a + /// ChannelManager object. pub chan_handler: Arc, + /// A message handler which handles messages updating our knowledge of the network channel + /// graph. Usually this is just a Router object. pub route_handler: Arc, } /// Provides an object which can be used to send data to and which uniquely identifies a connection /// to a remote host. You will need to be able to generate multiple of these which meet Eq and /// implement Hash to meet the PeerManager API. +/// /// For efficiency, Clone should be relatively cheap for this type. +/// /// You probably want to just extend an int and put a file descriptor in a struct and implement /// send_data. Note that if you are using a higher-level net library that may close() itself, be /// careful to ensure you don't have races whereby you might register a new connection with an fd @@ -30,9 +45,11 @@ pub trait SocketDescriptor : cmp::Eq + hash::Hash + Clone { /// Returns the amount of data which was sent, possibly 0 if the socket has since disconnected. /// Note that in the disconnected case, a disconnect_event must still fire and further write /// attempts may occur until that time. + /// /// If the returned size is smaller than data.len() - write_offset, a write_available event must /// trigger the next time more data can be written. Additionally, until the a send_data event /// completes fully, no further read_events should trigger on the same peer! + /// /// If a read_event on this descriptor had previously returned true (indicating that read /// events should be paused to prevent DoS in the send buffer), resume_read may be set /// indicating that read events on this descriptor should resume. A resume_read of false does @@ -51,6 +68,8 @@ pub trait SocketDescriptor : cmp::Eq + hash::Hash + Clone { /// disconnect_event (unless it was provided in response to a new_*_connection event, in which case /// no such disconnect_event must be generated and the socket be silently disconencted). pub struct PeerHandleError { + /// Used to indicate that we probably can't make any future connections to this peer, implying + /// we should go ahead and force-close any channels we have with it. no_connection_possible: bool, } impl fmt::Debug for PeerHandleError { @@ -103,6 +122,8 @@ impl PeerHolder { } } +/// A PeerManager manages a set of peers, described by their SocketDescriptor and marshalls socket +/// events into messages which it passes on to its MessageHandlers. pub struct PeerManager { message_handler: MessageHandler, peers: Mutex>, @@ -138,6 +159,7 @@ const INITIAL_SYNCS_TO_SEND: usize = 5; /// Manages and reacts to connection events. You probably want to use file descriptors as PeerIds. /// PeerIds may repeat, but only after disconnect_event() has been called. impl PeerManager { + /// Constructs a new PeerManager with the given message handlers and node_id secret key pub fn new(message_handler: MessageHandler, our_node_secret: SecretKey, logger: Arc) -> PeerManager { PeerManager { message_handler: message_handler, @@ -150,6 +172,7 @@ impl PeerManager { } /// Get the list of node ids for peers which have completed the initial handshake. + /// /// For outbound connections, this will be the same as the their_node_id parameter passed in to /// new_outbound_connection, however entries will only appear once the initial handshake has /// completed and we are sure the remote peer has the private key for the given node_id. @@ -166,7 +189,9 @@ impl PeerManager { /// Indicates a new outbound connection has been established to a node with the given node_id. /// Note that if an Err is returned here you MUST NOT call disconnect_event for the new /// descriptor but must disconnect the connection immediately. + /// /// Returns some bytes to send to the remote node. + /// /// Panics if descriptor is duplicative with some other descriptor which has not yet has a /// disconnect_event. pub fn new_outbound_connection(&self, their_node_id: PublicKey, descriptor: Descriptor) -> Result, PeerHandleError> { @@ -196,10 +221,12 @@ impl PeerManager { } /// Indicates a new inbound connection has been established. + /// /// May refuse the connection by returning an Err, but will never write bytes to the remote end /// (outbound connector always speaks first). Note that if an Err is returned here you MUST NOT /// call disconnect_event for the new descriptor but must disconnect the connection /// immediately. + /// /// Panics if descriptor is duplicative with some other descriptor which has not yet has a /// disconnect_event. pub fn new_inbound_connection(&self, descriptor: Descriptor) -> Result<(), PeerHandleError> { @@ -249,12 +276,14 @@ impl PeerManager { } /// Indicates that there is room to write data to the given socket descriptor. + /// /// May return an Err to indicate that the connection should be closed. + /// /// Will most likely call send_data on the descriptor passed in (or the descriptor handed into - /// new_*_connection) before returning. Thus, be very careful with reentrancy issues! The + /// new_*\_connection) before returning. Thus, be very careful with reentrancy issues! The /// invariants around calling write_event in case a write did not fully complete must still /// hold - be ready to call write_event again if a write call generated here isn't sufficient! - /// Panics if the descriptor was not previously registered in a new_*_connection event. + /// Panics if the descriptor was not previously registered in a new_\*_connection event. pub fn write_event(&self, descriptor: &mut Descriptor) -> Result<(), PeerHandleError> { let mut peers = self.peers.lock().unwrap(); match peers.peers.get_mut(descriptor) { @@ -268,16 +297,20 @@ impl PeerManager { } /// Indicates that data was read from the given socket descriptor. + /// /// May return an Err to indicate that the connection should be closed. + /// /// Will very likely call send_data on the descriptor passed in (or a descriptor handed into /// new_*_connection) before returning. Thus, be very careful with reentrancy issues! The /// invariants around calling write_event in case a write did not fully complete must still /// hold. Note that this function will often call send_data on many peers before returning, not /// just this peer! + /// /// If Ok(true) is returned, further read_events should not be triggered until a write_event on /// this file descriptor has resume_read set (preventing DoS issues in the send buffer). Note /// that this must be true even if a send_data call with resume_read=true was made during the /// course of this function! + /// /// Panics if the descriptor was not previously registered in a new_*_connection event. pub fn read_event(&self, peer_descriptor: &mut Descriptor, data: Vec) -> Result { match self.do_read_event(peer_descriptor, data) { @@ -357,14 +390,12 @@ impl PeerManager { Ok(x) => x, Err(e) => { match e { - msgs::DecodeError::UnknownRealmByte => return Err(PeerHandleError{ no_connection_possible: false }), + msgs::DecodeError::UnknownVersion => return Err(PeerHandleError{ no_connection_possible: false }), msgs::DecodeError::UnknownRequiredFeature => { log_debug!(self, "Got a channel/node announcement with an known required feature flag, you may want to udpate!"); continue; }, - msgs::DecodeError::BadPublicKey => return Err(PeerHandleError{ no_connection_possible: false }), - msgs::DecodeError::BadSignature => return Err(PeerHandleError{ no_connection_possible: false }), - msgs::DecodeError::BadText => return Err(PeerHandleError{ no_connection_possible: false }), + msgs::DecodeError::InvalidValue => return Err(PeerHandleError{ no_connection_possible: false }), msgs::DecodeError::ShortRead => return Err(PeerHandleError{ no_connection_possible: false }), msgs::DecodeError::ExtraAddressesPerType => { log_debug!(self, "Error decoding message, ignoring due to lnd spec incompatibility. See https://github.com/lightningnetwork/lnd/issues/1407"); @@ -372,7 +403,6 @@ impl PeerManager { }, msgs::DecodeError::BadLengthDescriptor => return Err(PeerHandleError{ no_connection_possible: false }), msgs::DecodeError::Io(_) => return Err(PeerHandleError{ no_connection_possible: false }), - msgs::DecodeError::InvalidValue => panic!("should not happen with message decoding"), } } }; @@ -451,14 +481,32 @@ impl PeerManager { 16 => { let msg = try_potential_decodeerror!(msgs::Init::read(&mut reader)); if msg.global_features.requires_unknown_bits() { + log_info!(self, "Peer global features required unknown version bits"); return Err(PeerHandleError{ no_connection_possible: true }); } if msg.local_features.requires_unknown_bits() { + log_info!(self, "Peer local features required unknown version bits"); + return Err(PeerHandleError{ no_connection_possible: true }); + } + if msg.local_features.requires_data_loss_protect() { + log_info!(self, "Peer local features required data_loss_protect"); + return Err(PeerHandleError{ no_connection_possible: true }); + } + if msg.local_features.requires_upfront_shutdown_script() { + log_info!(self, "Peer local features required upfront_shutdown_script"); return Err(PeerHandleError{ no_connection_possible: true }); } if peer.their_global_features.is_some() { return Err(PeerHandleError{ no_connection_possible: false }); } + + log_info!(self, "Received peer Init message: data_loss_protect: {}, initial_routing_sync: {}, upfront_shutdown_script: {}, unkown local flags: {}, unknown global flags: {}", + if msg.local_features.supports_data_loss_protect() { "supported" } else { "not supported"}, + if msg.local_features.initial_routing_sync() { "requested" } else { "not requested" }, + if msg.local_features.supports_upfront_shutdown_script() { "supported" } else { "not supported"}, + if msg.local_features.supports_unknown_bits() { "present" } else { "none" }, + if msg.global_features.supports_unknown_bits() { "present" } else { "none" }); + peer.their_global_features = Some(msg.global_features); peer.their_local_features = Some(msg.local_features); @@ -599,6 +647,9 @@ impl PeerManager { for resp in resps.update_fail_htlcs { encode_and_send_msg!(resp, 131); } + if let Some(resp) = resps.update_fee { + encode_and_send_msg!(resp, 134); + } encode_and_send_msg!(resps.commitment_signed, 132); }, None => {}, @@ -628,6 +679,9 @@ impl PeerManager { for resp in resps.update_fail_htlcs { encode_and_send_msg!(resp, 131); } + if let Some(resp) = resps.update_fee { + encode_and_send_msg!(resp, 134); + } encode_and_send_msg!(resps.commitment_signed, 132); }, None => {}, @@ -772,7 +826,7 @@ impl PeerManager { Self::do_attempt_write_data(&mut descriptor, peer); continue; }, - Event::UpdateHTLCs { ref node_id, updates: msgs::CommitmentUpdate { ref update_add_htlcs, ref update_fulfill_htlcs, ref update_fail_htlcs, ref update_fail_malformed_htlcs, ref commitment_signed } } => { + Event::UpdateHTLCs { ref node_id, updates: msgs::CommitmentUpdate { ref update_add_htlcs, ref update_fulfill_htlcs, ref update_fail_htlcs, ref update_fail_malformed_htlcs, ref update_fee, ref commitment_signed } } => { log_trace!(self, "Handling UpdateHTLCs event in peer_handler for node {} with {} adds, {} fulfills, {} fails for channel {}", log_pubkey!(node_id), update_add_htlcs.len(), @@ -794,6 +848,9 @@ impl PeerManager { for msg in update_fail_malformed_htlcs { peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg, 135))); } + if let &Some(ref msg) = update_fee { + peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg, 134))); + } peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(commitment_signed, 132))); Self::do_attempt_write_data(&mut descriptor, peer); continue; @@ -903,8 +960,10 @@ impl PeerManager { } /// Indicates that the given socket descriptor's connection is now closed. + /// /// This must be called even if a PeerHandleError was given for a read_event or write_event, - /// but must NOT be called if a PeerHandleError was provided out of a new_*_connection event! + /// but must NOT be called if a PeerHandleError was provided out of a new_\*\_connection event! + /// /// Panics if the descriptor was not previously registered in a successful new_*_connection event. pub fn disconnect_event(&self, descriptor: &Descriptor) { self.disconnect_event_internal(descriptor, false);