Kernel: Implement basic recvfrom

2024-02-02 13:50:00 +02:00
parent 7b287a1d5b
commit 0f154c3173
20 changed files with 339 additions and 116 deletions
--- a/kernel/kernel/Networking/E1000/E1000.cpp
+++ b/kernel/kernel/Networking/E1000/E1000.cpp
@@ -4,6 +4,7 @@
 #include <kernel/Memory/PageTable.h>
 #include <kernel/MMIO.h>
 #include <kernel/Networking/E1000/E1000.h>
+#include <kernel/Networking/NetworkManager.h>

 #define DEBUG_E1000 1

@@ -69,14 +70,7 @@ namespace Kernel
 		TRY(read_mac_address());
 #if DEBUG_E1000
 		dprintln("E1000 at PCI {}:{}.{}", m_pci_device.bus(), m_pci_device.dev(), m_pci_device.func());
-		dprintln("  MAC: {2H}:{2H}:{2H}:{2H}:{2H}:{2H}",
-			m_mac_address[0],
-			m_mac_address[1],
-			m_mac_address[2],
-			m_mac_address[3],
-			m_mac_address[4],
-			m_mac_address[5]
-		);
+		dprintln("  MAC: {}", m_mac_address);
 #endif

 		TRY(initialize_rx());
@@ -141,16 +135,16 @@ namespace Kernel
 		if (m_has_eerprom)
 		{
 			uint32_t temp = eeprom_read(0);
-			m_mac_address[0] = temp;
-			m_mac_address[1] = temp >> 8;
+			m_mac_address.address[0] = temp;
+			m_mac_address.address[1] = temp >> 8;

 			temp = eeprom_read(1);
-			m_mac_address[2] = temp;
-			m_mac_address[3] = temp >> 8;
+			m_mac_address.address[2] = temp;
+			m_mac_address.address[3] = temp >> 8;

 			temp = eeprom_read(2);
-			m_mac_address[4] = temp;
-			m_mac_address[5] = temp >> 8;
+			m_mac_address.address[4] = temp;
+			m_mac_address.address[5] = temp >> 8;

 			return {};
 		}
@@ -162,7 +156,7 @@ namespace Kernel
 		}

 		for (int i = 0; i < 6; i++)
-			m_mac_address[i] = (uint8_t)read32(0x5400 + i * 8);
+			m_mac_address.address[i] = (uint8_t)read32(0x5400 + i * 8);

 		return {};
 	}
@@ -175,7 +169,6 @@ namespace Kernel
 		auto* rx_descriptors = reinterpret_cast<volatile e1000_rx_desc*>(m_rx_descriptor_region->vaddr());
 		for (size_t i = 0; i < E1000_RX_DESCRIPTOR_COUNT; i++)
 		{
-			m_rx_buffers[i] = reinterpret_cast<void*>(m_rx_buffer_region->vaddr() + E1000_RX_BUFFER_SIZE * i);
 			rx_descriptors[i].addr = m_rx_buffer_region->paddr() + E1000_RX_BUFFER_SIZE * i;
 			rx_descriptors[i].status = 0;
 		}
@@ -209,7 +202,6 @@ namespace Kernel
 		auto* tx_descriptors = reinterpret_cast<volatile e1000_tx_desc*>(m_tx_descriptor_region->vaddr());
 		for (size_t i = 0; i < E1000_TX_DESCRIPTOR_COUNT; i++)
 		{
-			m_tx_buffers[i] = reinterpret_cast<void*>(m_tx_buffer_region->vaddr() + E1000_TX_BUFFER_SIZE * i);
 			tx_descriptors[i].addr = m_tx_buffer_region->paddr() + E1000_TX_BUFFER_SIZE * i;
 			tx_descriptors[i].cmd = 0;
 		}
@@ -300,8 +292,10 @@ namespace Kernel
 				break;
 			ASSERT_LTE((uint16_t)descriptor.length, E1000_RX_BUFFER_SIZE);

-			// FIXME: do something with the packet :)
-			dprintln("got {} byte packet", (uint16_t)descriptor.length);
+			NetworkManager::get().on_receive(BAN::ConstByteSpan {
+				reinterpret_cast<const uint8_t*>(m_rx_buffer_region->vaddr() + rx_current * E1000_RX_BUFFER_SIZE),
+				descriptor.length
+			});

 			descriptor.status = 0;
 			write32(REG_RDT0, rx_current);
--- a/kernel/kernel/Networking/IPv4.cpp
+++ b/kernel/kernel/Networking/IPv4.cpp
@@ -4,50 +4,19 @@
 namespace Kernel
 {

-
-	struct IPv4Header
+	void add_ipv4_header(BAN::ByteSpan packet, BAN::IPv4Address src_ipv4, BAN::IPv4Address dst_ipv4, uint8_t protocol)
 	{
-		uint8_t version_IHL;
-		uint8_t DSCP_ECN;
-		BAN::NetworkEndian<uint16_t> total_length;
-		BAN::NetworkEndian<uint16_t> identification;
-		BAN::NetworkEndian<uint16_t> flags_frament;
-		uint8_t time_to_live;
-		uint8_t protocol;
-		BAN::NetworkEndian<uint16_t> header_checksum;
-		BAN::NetworkEndian<uint32_t> src_address;
-		BAN::NetworkEndian<uint32_t> dst_address;
-
-		uint16_t checksum() const
-		{
-			return 0xFFFF
-				- (((uint16_t)version_IHL << 8) | DSCP_ECN)
-				- total_length
-				- identification
-				- flags_frament
-				- (((uint16_t)time_to_live << 8) | protocol);
-		}
-	};
-	static_assert(sizeof(IPv4Header) == 20);
-
-	BAN::ErrorOr<void> add_ipv4_header(BAN::Vector<uint8_t>& packet, uint32_t src_ipv4, uint32_t dst_ipv4, uint8_t protocol)
-	{
-		TRY(packet.resize(packet.size() + sizeof(IPv4Header)));
-		memmove(packet.data() + sizeof(IPv4Header), packet.data(), packet.size() - sizeof(IPv4Header));
-
-		auto* header = reinterpret_cast<IPv4Header*>(packet.data());
-		header->version_IHL		= 0x45;
-		header->DSCP_ECN		= 0x10;
-		header->total_length	= packet.size();
-		header->identification	= 1;
-		header->flags_frament	= 0x00;
-		header->time_to_live	= 0x40;
-		header->protocol		= protocol;
-		header->header_checksum = header->checksum();
-		header->src_address		= src_ipv4;
-		header->dst_address		= dst_ipv4;
-
-		return {};
+		auto& header = packet.as<IPv4Header>();
+		header.version_IHL		= 0x45;
+		header.DSCP_ECN			= 0x10;
+		header.total_length		= packet.size();
+		header.identification	= 1;
+		header.flags_frament	= 0x00;
+		header.time_to_live		= 0x40;
+		header.protocol			= protocol;
+		header.checksum			= header.calculate_checksum();
+		header.src_address		= src_ipv4;
+		header.dst_address		= dst_ipv4;
 	}

 }
--- a/kernel/kernel/Networking/NetworkInterface.cpp
+++ b/kernel/kernel/Networking/NetworkInterface.cpp
@@ -10,8 +10,8 @@ namespace Kernel

 	struct EthernetHeader
 	{
-		uint8_t dst_mac[6];
-		uint8_t src_mac[6];
+		BAN::MACAddress dst_mac;
+		BAN::MACAddress src_mac;
 		BAN::NetworkEndian<uint16_t> ether_type;
 	};
 	static_assert(sizeof(EthernetHeader) == 14);
@@ -40,19 +40,19 @@ namespace Kernel
 		m_name[3] = minor(m_rdev) + '0';
 	}

-	BAN::ErrorOr<void> NetworkInterface::add_interface_header(BAN::Vector<uint8_t>& packet, uint8_t destination_mac[6])
+	size_t NetworkInterface::interface_header_size() const
 	{
 		ASSERT(m_type == Type::Ethernet);
+		return sizeof(EthernetHeader);
+	}

-		TRY(packet.resize(packet.size() + sizeof(EthernetHeader)));
-		memmove(packet.data() + sizeof(EthernetHeader), packet.data(), packet.size() - sizeof(EthernetHeader));
-
-		auto* header = reinterpret_cast<EthernetHeader*>(packet.data());
-		memcpy(header->dst_mac, destination_mac, 6);
-		memcpy(header->src_mac, get_mac_address(), 6);
-		header->ether_type = 0x0800; // ipv4
-
-		return {};
+	void NetworkInterface::add_interface_header(BAN::ByteSpan packet, BAN::MACAddress destination)
+	{
+		ASSERT(m_type == Type::Ethernet);
+		auto& header = packet.as<EthernetHeader>();
+		header.dst_mac = destination;
+		header.src_mac = get_mac_address();
+		header.ether_type = 0x0800;
 	}

 }
--- a/kernel/kernel/Networking/NetworkManager.cpp
+++ b/kernel/kernel/Networking/NetworkManager.cpp
@@ -1,7 +1,9 @@
+#include <BAN/Endianness.h>
 #include <BAN/UniqPtr.h>
 #include <kernel/FS/DevFS/FileSystem.h>
 #include <kernel/Networking/E1000/E1000.h>
 #include <kernel/Networking/E1000/E1000E.h>
+#include <kernel/Networking/IPv4.h>
 #include <kernel/Networking/NetworkManager.h>
 #include <kernel/Networking/UDPSocket.h>

@@ -106,4 +108,27 @@ namespace Kernel
 		return {};
 	}

+	void NetworkManager::on_receive(BAN::ConstByteSpan packet)
+	{
+		// FIXME: properly handle packet parsing
+
+		auto ipv4 = packet.slice(14);
+		auto& ipv4_header = ipv4.as<const IPv4Header>();
+		auto src_ipv4 = ipv4_header.src_address;
+
+		auto udp = ipv4.slice(20);
+		auto& udp_header = udp.as<const UDPHeader>();
+		uint16_t src_port = udp_header.src_port;
+		uint16_t dst_port = udp_header.dst_port;
+
+		if (!m_bound_sockets.contains(dst_port))
+		{
+			dprintln("no one is listening on port {}", dst_port);
+			return;
+		}
+
+		auto raw = udp.slice(8);
+		m_bound_sockets[dst_port].lock()->add_packet(raw, src_ipv4, src_port);
+	}
+
 }
--- a/kernel/kernel/Networking/NetworkSocket.cpp
+++ b/kernel/kernel/Networking/NetworkSocket.cpp
@@ -65,18 +65,62 @@ namespace Kernel
 			return BAN::Error::from_errno(EINVAL);
 		}

-		static uint8_t dest_mac[6] { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
+		static BAN::MACAddress dest_mac {{ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }};
+
+		const size_t interface_header_offset	= 0;
+		const size_t interface_header_size		= m_interface->interface_header_size();
+
+		const size_t ipv4_header_offset	= interface_header_offset + interface_header_size;
+		const size_t ipv4_header_size	= sizeof(IPv4Header);
+
+		const size_t protocol_header_offset	= ipv4_header_offset + ipv4_header_size;
+		const size_t protocol_header_size	= this->protocol_header_size();
+
+		const size_t payload_offset	= protocol_header_offset + protocol_header_size;
+		const size_t payload_size	= message.size();

 		BAN::Vector<uint8_t> full_packet;
-		TRY(full_packet.resize(message.size()));
-		memcpy(full_packet.data(), message.data(), message.size());
-		TRY(add_protocol_header(full_packet, m_port, destination->sin_port));
-		TRY(add_ipv4_header(full_packet, m_interface->get_ipv4_address(), destination->sin_addr.s_addr, protocol()));
-		TRY(m_interface->add_interface_header(full_packet, dest_mac));
+		TRY(full_packet.resize(payload_offset + payload_size));

-		TRY(m_interface->send_raw_bytes(BAN::ConstByteSpan { full_packet.span() }));
+		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);
+		TRY(m_interface->send_raw_bytes(packet_bytespan));

 		return arguments->length;
 	}

+	BAN::ErrorOr<ssize_t> NetworkSocket::recvfrom_impl(sys_recvfrom_t* arguments)
+	{
+		sockaddr_in* sender_addr = nullptr;
+		if (arguments->address)
+		{
+			ASSERT(arguments->address_len);
+			if (*arguments->address_len < (socklen_t)sizeof(sockaddr_in))
+				*arguments->address_len = 0;
+			else
+			{
+				sender_addr = reinterpret_cast<sockaddr_in*>(arguments->address);
+				*arguments->address_len = sizeof(sockaddr_in);
+			}
+		}
+
+		if (!m_interface)
+		{
+			dprintln("No interface bound");
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+		if (m_port == PORT_NONE)
+		{
+			dprintln("No port bound");
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+		return TRY(read_packet(BAN::ByteSpan { reinterpret_cast<uint8_t*>(arguments->buffer), arguments->length }, sender_addr));
+	}
+
 }
--- a/kernel/kernel/Networking/UDPSocket.cpp
+++ b/kernel/kernel/Networking/UDPSocket.cpp
@@ -1,39 +1,101 @@
-#include <BAN/Endianness.h>
+#include <kernel/Memory/Heap.h>
 #include <kernel/Networking/UDPSocket.h>
+#include <kernel/Thread.h>

 namespace Kernel
 {

-	struct UDPHeader
-	{
-		BAN::NetworkEndian<uint16_t> src_port;
-		BAN::NetworkEndian<uint16_t> dst_port;
-		BAN::NetworkEndian<uint16_t> length;
-		BAN::NetworkEndian<uint16_t> checksum;
-	};
-	static_assert(sizeof(UDPHeader) == 8);
-
 	BAN::ErrorOr<BAN::RefPtr<UDPSocket>> UDPSocket::create(mode_t mode, uid_t uid, gid_t gid)
 	{
-		return TRY(BAN::RefPtr<UDPSocket>::create(mode, uid, gid));
+		auto socket = TRY(BAN::RefPtr<UDPSocket>::create(mode, uid, gid));
+		socket->m_packet_buffer = TRY(VirtualRange::create_to_vaddr_range(
+			PageTable::kernel(),
+			KERNEL_OFFSET,
+			~(uintptr_t)0,
+			packet_buffer_size,
+			PageTable::Flags::ReadWrite | PageTable::Flags::Present,
+			true
+		));
+		return socket;
 	}

 	UDPSocket::UDPSocket(mode_t mode, uid_t uid, gid_t gid)
 		: NetworkSocket(mode, uid, gid)
 	{ }

-	BAN::ErrorOr<void> UDPSocket::add_protocol_header(BAN::Vector<uint8_t>& packet, uint16_t src_port, uint16_t dst_port)
+	void UDPSocket::add_protocol_header(BAN::ByteSpan packet, uint16_t src_port, uint16_t dst_port)
 	{
-		TRY(packet.resize(packet.size() + sizeof(UDPHeader)));
-		memmove(packet.data() + sizeof(UDPHeader), packet.data(), packet.size() - sizeof(UDPHeader));
+		auto& header = packet.as<UDPHeader>();
+		header.src_port = src_port;
+		header.dst_port = dst_port;
+		header.length = packet.size();
+		header.checksum = 0;
+	}

-		auto* header = reinterpret_cast<UDPHeader*>(packet.data());
-		header->src_port = src_port;
-		header->dst_port = dst_port;
-		header->length = packet.size();
-		header->checksum = 0;
+	void UDPSocket::add_packet(BAN::ConstByteSpan packet, BAN::IPv4Address sender_addr, uint16_t sender_port)
+	{
+		CriticalScope _;

-		return {};
+		if (m_packets.full())
+		{
+			dprintln("Packet buffer full, dropping packet");
+			return;
+		}
+
+		if (!m_packets.empty() && m_packet_total_size > m_packet_buffer->size())
+		{
+			dprintln("Packet buffer full, dropping packet");
+			return;
+		}
+
+		void* buffer = reinterpret_cast<void*>(m_packet_buffer->vaddr() + m_packet_total_size);
+		memcpy(buffer, packet.data(), packet.size());
+
+		m_packets.push(PacketInfo {
+			.sender_addr = sender_addr,
+			.sender_port = sender_port,
+			.packet_size = packet.size()
+		});
+		m_packet_total_size += packet.size();
+
+		m_semaphore.unblock();
+	}
+
+	BAN::ErrorOr<size_t> UDPSocket::read_packet(BAN::ByteSpan buffer, sockaddr_in* sender_addr)
+	{
+		while (m_packets.empty())
+			TRY(Thread::current().block_or_eintr(m_semaphore));
+
+		CriticalScope _;
+		if (m_packets.empty())
+			return read_packet(buffer, sender_addr);
+
+		auto packet_info = m_packets.front();
+		m_packets.pop();
+
+		size_t nread = BAN::Math::min<size_t>(packet_info.packet_size, buffer.size());
+
+		memcpy(
+			buffer.data(),
+			(const void*)m_packet_buffer->vaddr(),
+			nread
+		);
+		memmove(
+			(void*)m_packet_buffer->vaddr(),
+			(void*)(m_packet_buffer->vaddr() + packet_info.packet_size),
+			m_packet_total_size - packet_info.packet_size
+		);
+
+		m_packet_total_size -= packet_info.packet_size;
+
+		if (sender_addr)
+		{
+			sender_addr->sin_family = AF_INET;
+			sender_addr->sin_port = packet_info.sender_port;
+			sender_addr->sin_addr.s_addr = packet_info.sender_addr.as_u32();
+		}
+
+		return nread;
 	}

 }