From 73e0b1016d15dcb45b55501e73609f73871cdcdb Mon Sep 17 00:00:00 2001
From: Siarhei Dziki <s.dikiy@strikerz.inc>
Date: Sat, 2 Mar 2024 12:55:19 +0100
Subject: [PATCH] more relay stuff

---
 src/relay/relay.cxx | 43 +++++++++++++++++++++++++++++++++++--------
 src/relay/relay.hxx |  4 +++-
 src/relay/types.hxx | 30 +++++++++++++++++++++++-------
 3 files changed, 61 insertions(+), 16 deletions(-)

diff --git a/src/relay/relay.cxx b/src/relay/relay.cxx
index b479f97..554a8ea 100644
--- a/src/relay/relay.cxx
+++ b/src/relay/relay.cxx
@@ -10,7 +10,7 @@
 bool relay::init()
 {
 	m_socket = udpsocketFactory::createUdpSocket();
-	if (!m_socket->isValid())
+	if (m_socket == nullptr || !m_socket->isValid())
 	{
 		LOG(Error, "Failed to create socket!");
 		return false;
@@ -26,6 +26,16 @@ bool relay::init()
 	return true;
 }
 
+channel& relay::createChannel(const guid& inGuid)
+{
+	channel newChannel{};
+	newChannel.m_guid = inGuid;
+
+	LOG(Display, "Created channel with guid: {0}", inGuid.toString());
+
+	return *m_channels.emplace_after(m_channels.before_begin(), newChannel);
+}
+
 bool relay::run()
 {
 	if (!init())
@@ -33,7 +43,7 @@ bool relay::run()
 
 	LOG(Display, "Relay initialized and running on port {0}", mainPort);
 
-	std::unique_ptr<internetaddr> recvAddr = udpsocketFactory::createInternetAddrUnique();
+	std::shared_ptr<internetaddr> recvAddr = udpsocketFactory::createInternetAddrUnique();
 
 	std::array<uint8_t, 1024> buffer{};
 	m_running = true;
@@ -54,20 +64,37 @@ bool relay::run()
 			//	continue;
 			//}
 
-			if (bytesRead == 1024)
+			if (bytesRead == 1024) // const handshake packet size
 			{
 				const handshake_header* header = reinterpret_cast<const handshake_header*>(buffer.data());
 
-				LOG(Verbose, "Received header: type: {0}, length: {1} from {2}", header->type, header->length, recvAddr->toString());
+				LOG(Verbose, "Received header: type: {0}, length: {1} from {2}", header->m_type, header->m_length, recvAddr->toString());
 
-				auto nthType = NETWORK_TO_HOST_16(header->type);
-				auto nthLength = NETWORK_TO_HOST_16(header->length);
+				auto nthType = NETWORK_TO_HOST_16(header->m_type);
+				auto nthLength = NETWORK_TO_HOST_16(header->m_length);
 
 				LOG(Verbose, "Swapped header: type: {0}, length: {1} from {2}", nthType, nthLength, recvAddr->toString());
 
-				if (nthType == 0x01 && nthLength == 1024)
+				if (nthType == 0x01 && nthLength == 992) // const handshake packet values
 				{
-					LOG(Display, "you win!");
+					const auto& recvGuid = header->m_id;
+					const guid htnGuid = guid(NETWORK_TO_HOST_16(recvGuid.m_a), NETWORK_TO_HOST_16(recvGuid.m_b), NETWORK_TO_HOST_16(recvGuid.m_c), NETWORK_TO_HOST_16(recvGuid.m_d));
+
+					auto guidChannel = m_guidMappedChannels.find(htnGuid);
+					if (guidChannel == m_guidMappedChannels.end())
+					{
+						channel& newChannel = createChannel(htnGuid);
+						newChannel.m_peerA = recvAddr;
+					}
+					else if (*guidChannel->second.m_peerA != *recvAddr)
+					{
+						guidChannel->second.m_peerB = recvAddr;
+
+						LOG(Display, "Creating relay for session: {0} with peers: {1}, {2}.", htnGuid.toString(), guidChannel->second.m_peerA, guidChannel->second.m_peerB);
+
+						m_addressMappedChannels.emplace(guidChannel->second.m_peerA, guidChannel->second);
+						m_addressMappedChannels.emplace(guidChannel->second.m_peerB, guidChannel->second);
+					}
 				}
 			}
 		}
diff --git a/src/relay/relay.hxx b/src/relay/relay.hxx
index b8774b0..5ad5c6a 100644
--- a/src/relay/relay.hxx
+++ b/src/relay/relay.hxx
@@ -38,11 +38,13 @@ public:
 private:
 	bool init();
 
+	channel& createChannel(const guid& inGuid);
+
 	std::unique_ptr<udpsocket> m_socket{};
 
 	std::forward_list<channel> m_channels{};
 
-	std::unordered_map<guid, const channel&> m_guidMappedChannels{};
+	std::unordered_map<guid, channel&> m_guidMappedChannels{};
 
 	std::unordered_map<std::shared_ptr<internetaddr>, const channel&> m_addressMappedChannels{};
 
diff --git a/src/relay/types.hxx b/src/relay/types.hxx
index 17a33bd..c6db824 100644
--- a/src/relay/types.hxx
+++ b/src/relay/types.hxx
@@ -3,19 +3,35 @@
 
 struct guid
 {
-	int32_t a{};
-	int32_t b{};
-	int32_t c{};
-	int32_t d{};
+	guid() = default;
+	guid(int32_t a, int32_t b, int32_t c, int32_t d) 
+		: m_a{a}
+		, m_b{b}
+		, m_c{c}
+		, m_d{d}
+	{
+	}
+
+	int32_t m_a{};
+	int32_t m_b{};
+	int32_t m_c{};
+	int32_t m_d{};
 
 	bool operator<=>(const guid&) const = default;
+
+	std::string toString() const
+	{
+		char buffer[36]{};
+		std::snprintf(buffer, sizeof(buffer), "%08x-%04x-%04x-%04x-%04x%08x", m_a, m_b >> 16, m_b & 0xFFFF, m_c >> 16, m_c & 0xFFFF, m_d);
+		return std::string(buffer);
+	}
 };
 
 struct handshake_header
 {
-	uint16_t type{};
-	uint16_t length{};
-	guid id{};
+	uint16_t m_type{};
+	uint16_t m_length{};
+	guid m_id{};
 };
 
 // custom hash for guid