Introduce ARP layer

kernel/include/arp_layer.hpp

@@ -0,0 +1,33 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2016.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#ifndef NET_ARP_LAYER_H
+#define NET_ARP_LAYER_H
+
+#include <types.hpp>
+
+#include "ethernet_layer.hpp"
+
+namespace network {
+
+namespace arp {
+
+struct header {
+    uint16_t hw_type;
+    uint16_t protocol_type;
+    uint8_t hw_len;
+    uint8_t protocol_len;
+    uint16_t operation;
+} __attribute__((packed));
+
+void decode(network::ethernet::packet& packet);
+
+} // end of arp namespace
+
+} // end of network namespace
+
+#endif

kernel/include/ethernet_layer.hpp

@@ -29,8 +29,9 @@ struct packet {
 
     // Set by ethernet
     ether_type type;
+    size_t index;
 
-    packet(char* payload, size_t payload_size) : payload(payload), payload_size(payload_size) {}
+    packet(char* payload, size_t payload_size) : payload(payload), payload_size(payload_size), index(0) {}
 };
 
 struct address {

kernel/src/arp_layer.cpp

@@ -0,0 +1,46 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2016.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#include <vector.hpp>
+#include <string.hpp>
+
+#include "arp_layer.hpp"
+#include "logging.hpp"
+#include "kernel_utils.hpp"
+
+namespace {
+
+//TODO
+
+} //end of anonymous namespace
+
+void network::arp::decode(network::ethernet::packet& packet){
+    header* arp_header = reinterpret_cast<header*>(packet.payload + packet.index);
+
+    logging::logf(logging::log_level::TRACE, "arp: Start ARP packet handling\n");
+
+    auto hw_type = switch_endian_16(arp_header->hw_type);
+    auto protocol_type = switch_endian_16(arp_header->protocol_type);
+
+    if(hw_type != 0x1){
+        logging::logf(logging::log_level::ERROR, "arp: Unhandled hardware type %h\n", size_t(hw_type));
+        return;
+    }
+
+    if(protocol_type != 0x800){
+        logging::logf(logging::log_level::ERROR, "arp: Unhandled protocol type %h\n", size_t(protocol_type));
+        return;
+    }
+
+    auto hw_len = arp_header->hw_len;
+    auto protocol_len = arp_header->protocol_len;
+    auto operation = switch_endian_16(arp_header->operation);
+
+    logging::logf(logging::log_level::TRACE, "arp: Start ARP packet handling %h\n", size_t(hw_len));
+    logging::logf(logging::log_level::TRACE, "arp: Start ARP packet handling %h\n", size_t(protocol_len));
+    logging::logf(logging::log_level::TRACE, "arp: Start ARP packet handling %h\n", size_t(operation));
+}

kernel/src/ethernet_layer.cpp

@@ -11,6 +11,7 @@
 #include "ethernet_layer.hpp"
 #include "logging.hpp"
 #include "kernel_utils.hpp"
+#include "arp_layer.hpp"
 
 namespace {
 
@@ -51,6 +52,7 @@ void network::ethernet::decode(packet& packet){
     logging::logf(logging::log_level::TRACE, "ethernet: Destination MAC Address %h \n", target_mac);
 
     packet.type = decode_ether_type(ether_header);
+    packet.index += sizeof(header);
 
     switch(packet.type){
         case ether_type::IPV4:
@@ -60,7 +62,7 @@ void network::ethernet::decode(packet& packet){
             logging::logf(logging::log_level::TRACE, "ethernet: IPV6 Packet (unsupported)\n");
             break;
         case ether_type::ARP:
-            logging::logf(logging::log_level::TRACE, "ethernet: ARP Packet (unsupported)\n");
+            network::arp::decode(packet);
             break;
         case ether_type::UNKNOWN:
             logging::logf(logging::log_level::TRACE, "ethernet: Unhandled Packet Type: %u\n", uint64_t(switch_endian_16(ether_header->type)));