Kernel: Implement barebones arp table

kernel/CMakeLists.txt

@@ -49,6 +49,7 @@ set(KERNEL_SOURCES
 	kernel/Memory/MemoryRegion.cpp
 	kernel/Memory/PhysicalRange.cpp
 	kernel/Memory/VirtualRange.cpp
+	kernel/Networking/ARPTable.cpp
 	kernel/Networking/E1000/E1000.cpp
 	kernel/Networking/E1000/E1000E.cpp
 	kernel/Networking/IPv4.cpp

kernel/include/kernel/Networking/ARPTable.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <BAN/HashMap.h>
+#include <BAN/IPv4.h>
+#include <BAN/MAC.h>
+#include <BAN/UniqPtr.h>
+
+namespace Kernel
+{
+
+	class ARPTable
+	{
+		BAN_NON_COPYABLE(ARPTable);
+		BAN_NON_MOVABLE(ARPTable);
+
+	public:
+		static BAN::ErrorOr<BAN::UniqPtr<ARPTable>> create();
+
+		BAN::ErrorOr<BAN::MACAddress> get_mac_from_ipv4(BAN::IPv4Address);
+
+	private:
+		ARPTable();
+
+	private:
+		BAN::HashMap<BAN::IPv4Address, BAN::MACAddress> m_arp_table;
+
+		friend class BAN::UniqPtr<ARPTable>;
+	};
+
+}

kernel/include/kernel/Networking/NetworkManager.h

@@ -2,6 +2,7 @@
 
 #include <BAN/Vector.h>
 #include <kernel/FS/TmpFS/FileSystem.h>
+#include <kernel/Networking/ARPTable.h>
 #include <kernel/Networking/NetworkInterface.h>
 #include <kernel/Networking/NetworkSocket.h>
 #include <kernel/PCI.h>
@@ -13,6 +14,9 @@ namespace Kernel
 
 	class NetworkManager : public TmpFileSystem
 	{
+		BAN_NON_COPYABLE(NetworkManager);
+		BAN_NON_MOVABLE(NetworkManager);
+
 	public:
 		enum class SocketType
 		{
@@ -25,6 +29,8 @@ namespace Kernel
 		static BAN::ErrorOr<void> initialize();
 		static NetworkManager& get();
 
+		ARPTable& arp_table() { return *m_arp_table; }
+
 		BAN::ErrorOr<void> add_interface(PCI::Device& pci_device);
 
 		void unbind_socket(uint16_t port, BAN::RefPtr<NetworkSocket>);
@@ -38,6 +44,7 @@ namespace Kernel
 		NetworkManager();
 
 	private:
+		BAN::UniqPtr<ARPTable>							m_arp_table;
 		BAN::Vector<BAN::RefPtr<NetworkInterface>>		m_interfaces;
 		BAN::HashMap<int, BAN::WeakPtr<NetworkSocket>>	m_bound_sockets;
 	};

kernel/include/kernel/Networking/NetworkSocket.h

@@ -11,6 +11,9 @@ namespace Kernel
 
 	class NetworkSocket : public TmpInode, public BAN::Weakable<NetworkSocket>
 	{
+		BAN_NON_COPYABLE(NetworkSocket);
+		BAN_NON_MOVABLE(NetworkSocket);
+
 	public:
 		static constexpr uint16_t PORT_NONE = 0;
 

kernel/kernel/Networking/ARPTable.cpp

@@ -0,0 +1,27 @@
+#include <kernel/Networking/ARPTable.h>
+
+namespace Kernel
+{
+
+	static constexpr BAN::IPv4Address	s_broadcast_ipv4 { 0xFFFFFFFF };
+	static constexpr BAN::MACAddress	s_broadcast_mac {{ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }};
+
+	BAN::ErrorOr<BAN::UniqPtr<ARPTable>> ARPTable::create()
+	{
+		return TRY(BAN::UniqPtr<ARPTable>::create());
+	}
+
+	ARPTable::ARPTable()
+	{
+
+	}
+
+	BAN::ErrorOr<BAN::MACAddress> ARPTable::get_mac_from_ipv4(BAN::IPv4Address ipv4_address)
+	{
+		if (ipv4_address == s_broadcast_ipv4)
+			return s_broadcast_mac;
+		dprintln("No MAC for IPv4 {}", ipv4_address);
+		return BAN::Error::from_errno(ENOTSUP);
+	}
+
+}

kernel/kernel/Networking/NetworkManager.cpp

@@ -19,6 +19,7 @@ namespace Kernel
 		if (manager_ptr == nullptr)
 			return BAN::Error::from_errno(ENOMEM);
 		auto manager = BAN::UniqPtr<NetworkManager>::adopt(manager_ptr);
+		manager->m_arp_table = TRY(ARPTable::create());
 		TRY(manager->TmpFileSystem::initialize(0777, 0, 0));
 		s_instance = BAN::move(manager);
 		return {};

kernel/kernel/Networking/NetworkSocket.cpp

@@ -58,16 +58,12 @@ namespace Kernel
 		auto* destination = reinterpret_cast<const sockaddr_in*>(arguments->dest_addr);
 		auto  message = BAN::ConstByteSpan((const uint8_t*)arguments->message, arguments->length);
 
-		if (destination->sin_port == PORT_NONE)
+		uint16_t dst_port = destination->sin_port;
+		if (dst_port == PORT_NONE)
 			return BAN::Error::from_errno(EINVAL);
 
-		if (destination->sin_addr.s_addr != 0xFFFFFFFF)
-		{
-			dprintln("Only broadcast ip supported");
-			return BAN::Error::from_errno(EINVAL);
-		}
-
-		static BAN::MACAddress dest_mac {{ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }};
+		auto dst_addr = BAN::IPv4Address(destination->sin_addr.s_addr);
+		auto dst_mac = TRY(NetworkManager::get().arp_table().get_mac_from_ipv4(dst_addr));
 
 		const size_t interface_header_offset	= 0;
 		const size_t interface_header_size		= m_interface->interface_header_size();
@@ -87,9 +83,9 @@ namespace Kernel
 		BAN::ByteSpan packet_bytespan { full_packet.span() };
 
 		memcpy(full_packet.data() + payload_offset, message.data(), payload_size);
-		add_protocol_header(packet_bytespan.slice(protocol_header_offset), m_port, destination->sin_port);
-		add_ipv4_header(packet_bytespan.slice(ipv4_header_offset), m_interface->get_ipv4_address(), destination->sin_addr.s_addr, protocol());
-		m_interface->add_interface_header(packet_bytespan.slice(interface_header_offset), dest_mac);
+		add_protocol_header(packet_bytespan.slice(protocol_header_offset), m_port, dst_port);
+		add_ipv4_header(packet_bytespan.slice(ipv4_header_offset), m_interface->get_ipv4_address(), dst_addr, protocol());
+		m_interface->add_interface_header(packet_bytespan.slice(interface_header_offset), dst_mac);
 		TRY(m_interface->send_raw_bytes(packet_bytespan));
 
 		return arguments->length;