From 05e2a7dc48f11a7f258f59acd769e4874c022a87 Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Sat, 16 Jun 2018 19:39:21 -0400
Subject: [PATCH] Support responding to Ping messages in peer_handler

---
 src/ln/msgs.rs         | 57 ++++++++++++++++++++++++++++++++++++++++++
 src/ln/peer_handler.rs | 11 ++++++--
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/src/ln/msgs.rs b/src/ln/msgs.rs
index f0f1d4890..869b5115f 100644
--- a/src/ln/msgs.rs
+++ b/src/ln/msgs.rs
@@ -132,6 +132,15 @@ pub struct Init {
 	pub local_features: LocalFeatures,
 }
 
+pub struct Ping {
+	pub ponglen: u16,
+	pub byteslen: u16,
+}
+
+pub struct Pong {
+	pub byteslen: u16,
+}
+
 pub struct OpenChannel {
 	pub chain_hash: Sha256dHash,
 	pub temporary_channel_id: Uint256,
@@ -572,6 +581,54 @@ impl MsgEncodable for Init {
 	}
 }
 
+impl MsgDecodable for Ping {
+	fn decode(v: &[u8]) -> Result<Self, DecodeError> {
+		if v.len() < 4 {
+			return Err(DecodeError::WrongLength);
+		}
+		let ponglen = byte_utils::slice_to_be16(&v[0..2]);
+		let byteslen = byte_utils::slice_to_be16(&v[2..4]);
+		if v.len() < 4 + byteslen as usize {
+			return Err(DecodeError::WrongLength);
+		}
+		Ok(Self {
+			ponglen,
+			byteslen,
+		})
+	}
+}
+impl MsgEncodable for Ping {
+	fn encode(&self) -> Vec<u8> {
+		let mut res = Vec::with_capacity(self.byteslen as usize + 2);
+		res.extend_from_slice(&byte_utils::be16_to_array(self.byteslen));
+		res.resize(2 + self.byteslen as usize, 0);
+		res
+	}
+}
+
+impl MsgDecodable for Pong {
+	fn decode(v: &[u8]) -> Result<Self, DecodeError> {
+		if v.len() < 2 {
+			return Err(DecodeError::WrongLength);
+		}
+		let byteslen = byte_utils::slice_to_be16(&v[0..2]);
+		if v.len() < 2 + byteslen as usize {
+			return Err(DecodeError::WrongLength);
+		}
+		Ok(Self {
+			byteslen
+		})
+	}
+}
+impl MsgEncodable for Pong {
+	fn encode(&self) -> Vec<u8> {
+		let mut res = Vec::with_capacity(self.byteslen as usize + 2);
+		res.extend_from_slice(&byte_utils::be16_to_array(self.byteslen));
+		res.resize(2 + self.byteslen as usize, 0);
+		res
+	}
+}
+
 impl MsgDecodable for OpenChannel {
 	fn decode(v: &[u8]) -> Result<Self, DecodeError> {
 		if v.len() < 2*32+6*8+4+2*2+6*33+1 {
diff --git a/src/ln/peer_handler.rs b/src/ln/peer_handler.rs
index 3c4196519..30900cab4 100644
--- a/src/ln/peer_handler.rs
+++ b/src/ln/peer_handler.rs
@@ -390,8 +390,15 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
 											17 => {
 												// Error msg
 											},
-											18 => { }, // ping
-											19 => { }, // pong
+
+											18 => {
+												let msg = try_potential_decodeerror!(msgs::Ping::decode(&msg_data[2..]));
+												let resp = msgs::Pong { byteslen: msg.ponglen };
+												encode_and_send_msg!(resp, 19);
+											},
+											19 => {
+												try_potential_decodeerror!(msgs::Pong::decode(&msg_data[2..]));
+											},
 
 											// Channel control:
 											32 => {
-- 
2.39.5