From d26902468df9e7eaa42bb231e01277ceac9b7fcb Mon Sep 17 00:00:00 2001
From: SChernykh <sergey.v.chernykh@gmail.com>
Date: Thu, 21 Oct 2021 15:55:00 +0200
Subject: [PATCH] P2PServer: peer list tweaks

- Increase outgoing connections to 10
- Stricter handling of peer list responses
---
 src/p2p_server.cpp | 17 ++++++++++++-----
 src/tcp_server.inl |  1 -
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/p2p_server.cpp b/src/p2p_server.cpp
index 5850f1f..303f820 100644
--- a/src/p2p_server.cpp
+++ b/src/p2p_server.cpp
@@ -225,8 +225,8 @@ void P2PServer::update_peer_connections()
 		peer_list = m_peerList;
 	}
 
-	// Try to have at least 8 outgoing connections
-	for (uint32_t i = m_numConnections - m_numIncomingConnections; (i < 8) && !peer_list.empty();) {
+	// Try to have at least 10 outgoing connections
+	for (uint32_t i = m_numConnections - m_numIncomingConnections; (i < 10) && !peer_list.empty();) {
 		const uint64_t k = get_random64() % peer_list.size();
 		const Peer& peer = peer_list[k];
 
@@ -1041,7 +1041,7 @@ bool P2PServer::P2PClient::on_read(char* data, uint32_t size)
 			LOGINFO(5, "peer " << log::Gray() << static_cast<char*>(m_addrString) << log::NoColor() << " sent PEER_LIST_RESPONSE");
 
 			if (bytes_left >= 2) {
-				const uint8_t num_peers = buf[1];
+				const uint32_t num_peers = buf[1];
 				if (num_peers > PEER_LIST_RESPONSE_MAX_PEERS) {
 					LOGWARN(5, "peer " << log::Gray() << static_cast<char*>(m_addrString) << log::NoColor() << " sent too long peer list (" << num_peers << ')');
 					ban(DEFAULT_BAN_TIME);
@@ -1049,8 +1049,8 @@ bool P2PServer::P2PClient::on_read(char* data, uint32_t size)
 					return false;
 				}
 
-				if (bytes_left >= 2u + num_peers * 19) {
-					bytes_read = 2u + num_peers * 19;
+				if (bytes_left >= 2u + num_peers * 19u) {
+					bytes_read = 2u + num_peers * 19u;
 
 					--m_peerListPendingRequests;
 					if (!on_peer_list_response(buf + 1)) {
@@ -1609,6 +1609,13 @@ bool P2PServer::P2PClient::on_peer_list_response(const uint8_t* buf) const
 		memcpy(ip.data, buf, sizeof(ip.data));
 		buf += sizeof(ip.data);
 
+		// Fill in default bytes for IPv4 addresses
+		if (!is_v6) {
+			memset(ip.data, 0, 10);
+			ip.data[10] = 0xFF;
+			ip.data[11] = 0xFF;
+		}
+
 		int port = 0;
 		memcpy(&port, buf, 2);
 		buf += 2;
diff --git a/src/tcp_server.inl b/src/tcp_server.inl
index f841902..b2a8563 100644
--- a/src/tcp_server.inl
+++ b/src/tcp_server.inl
@@ -308,7 +308,6 @@ bool TCPServer<READ_BUF_SIZE, WRITE_BUF_SIZE>::connect_to_peer(bool is_v6, const
 	return connect_to_peer_nolock(client, is_v6, reinterpret_cast<sockaddr*>(&addr));
 }
 
-
 template<size_t READ_BUF_SIZE, size_t WRITE_BUF_SIZE>
 void TCPServer<READ_BUF_SIZE, WRITE_BUF_SIZE>::on_connect_failed(bool, const raw_ip&, int)
 {