Prepare TCP support

kernel/include/net/tcp_layer.hpp

@@ -0,0 +1,42 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2016.
+// Distributed under the terms of the MIT License.
+// (See accompanying file LICENSE or copy at
+//  http://www.opensource.org/licenses/MIT)
+//=======================================================================
+
+#ifndef NET_TCP_LAYER_H
+#define NET_TCP_LAYER_H
+
+#include <types.hpp>
+
+#include "net/ethernet_layer.hpp"
+#include "net/ip_layer.hpp"
+#include "net/network.hpp"
+
+namespace network {
+
+namespace tcp {
+
+struct header {
+    uint16_t source_port;
+    uint16_t target_port;
+    uint32_t sequence_number;
+    uint32_t ack_number;
+    uint16_t flags;
+    uint16_t window_size;
+    uint16_t checksum;
+    uint16_t urgent_pointer;
+} __attribute__((packed));
+
+void decode(network::interface_descriptor& interface, network::ethernet::packet& packet);
+
+std::expected<network::ethernet::packet> prepare_packet(network::interface_descriptor& interface, network::ip::address target_ip, size_t source, size_t target, size_t payload_size);
+std::expected<network::ethernet::packet> prepare_packet(char* buffer, network::interface_descriptor& interface, network::ip::address target_ip, size_t source, size_t target, size_t payload_size);
+void finalize_packet(network::interface_descriptor& interface, network::ethernet::packet& p);
+
+} // end of tcp namespace
+
+} // end of network namespace
+
+#endif

kernel/src/net/ip_layer.cpp

@@ -12,6 +12,7 @@
 #include "net/ethernet_layer.hpp"
 #include "net/icmp_layer.hpp"
 #include "net/udp_layer.hpp"
+#include "net/tcp_layer.hpp"
 #include "net/arp_cache.hpp"
 
 #include "logging.hpp"
@@ -143,7 +144,7 @@ void network::ip::decode(network::interface_descriptor& interface, network::ethe
     if(protocol == 0x01){
         network::icmp::decode(interface, packet);
     } else if(protocol == 0x06){
-        logging::logf(logging::log_level::ERROR, "ip: TCP packet detected (unsupported)\n");
+        network::tcp::decode(interface, packet);
     } else if(protocol == 0x11){
         network::udp::decode(interface, packet);
     } else {

kernel/src/net/tcp_layer.cpp

@@ -0,0 +1,89 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2016.
+// Distributed under the terms of the MIT License.
+// (See accompanying file LICENSE or copy at
+//  http://www.opensource.org/licenses/MIT)
+//=======================================================================
+
+#include "net/tcp_layer.hpp"
+#include "net/dns_layer.hpp"
+
+#include "kernel_utils.hpp"
+
+namespace {
+
+void compute_checksum(network::ethernet::packet& packet){
+    auto* ip_header  = reinterpret_cast<network::ip::header*>(packet.payload + packet.tag(1));
+    auto* tcp_header = reinterpret_cast<network::tcp::header*>(packet.payload + packet.index);
+
+    tcp_header->checksum = 0;
+
+    //TODO
+}
+
+void prepare_packet(network::ethernet::packet& packet, size_t source, size_t target, size_t payload_size){
+    packet.tag(2, packet.index);
+
+    // Set the TCP header
+
+    auto* tcp_header = reinterpret_cast<network::tcp::header*>(packet.payload + packet.index);
+
+    tcp_header->source_port = switch_endian_16(source);
+    tcp_header->target_port = switch_endian_16(target);
+
+    //TODO
+
+    packet.index += sizeof(network::tcp::header);
+}
+
+} //end of anonymous namespace
+
+void network::tcp::decode(network::interface_descriptor& interface, network::ethernet::packet& packet){
+    packet.tag(2, packet.index);
+
+    auto* tcp_header = reinterpret_cast<header*>(packet.payload + packet.index);
+
+    logging::logf(logging::log_level::TRACE, "tcp: Start TCP packet handling\n");
+
+    auto source_port = switch_endian_16(tcp_header->source_port);
+    auto target_port = switch_endian_16(tcp_header->target_port);
+
+    logging::logf(logging::log_level::TRACE, "tcp: Source Port %h \n", source_port);
+    logging::logf(logging::log_level::TRACE, "tcp: Target Port %h \n", target_port);
+
+    packet.index += sizeof(header);
+
+    //TODO
+}
+
+std::expected<network::ethernet::packet> network::tcp::prepare_packet(network::interface_descriptor& interface, network::ip::address target_ip, size_t source, size_t target, size_t payload_size){
+    // Ask the IP layer to craft a packet
+    auto packet = network::ip::prepare_packet(interface, sizeof(header) + payload_size, target_ip, 0x11);
+
+    if(packet){
+        ::prepare_packet(*packet, source, target, payload_size);
+    }
+
+    return packet;
+}
+
+std::expected<network::ethernet::packet> network::tcp::prepare_packet(char* buffer, network::interface_descriptor& interface, network::ip::address target_ip, size_t source, size_t target, size_t payload_size){
+    // Ask the IP layer to craft a packet
+    auto packet = network::ip::prepare_packet(buffer, interface, sizeof(header) + payload_size, target_ip, 0x11);
+
+    if(packet){
+        ::prepare_packet(*packet, source, target, payload_size);
+    }
+
+    return packet;
+}
+
+void network::tcp::finalize_packet(network::interface_descriptor& interface, network::ethernet::packet& p){
+    p.index -= sizeof(header);
+
+    // Compute the checksum
+    compute_checksum(p);
+
+    // Give the packet to the IP layer for finalization
+    network::ip::finalize_packet(interface, p);
+}