net: Extracted IP4 Header

Author: AndreasAakesson

api/net/ip4/header.hpp

@@ -0,0 +1,43 @@
+// This file is a part of the IncludeOS unikernel - www.includeos.org
+//
+// Copyright 2015-2016 Oslo and Akershus University College of Applied Sciences
+// and Alfred Bratterud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#pragma once
+
+#ifndef NET_IP4_HEADER_HPP
+#define NET_IP4_HEADER_HPP
+
+namespace net {
+namespace ip4 {
+
+/** IP4 header representation */
+struct Header {
+  uint8_t  version_ihl;
+  uint8_t  tos;
+  uint16_t tot_len;
+  uint16_t id;
+  uint16_t frag_off_flags;
+  uint8_t  ttl;
+  uint8_t  protocol;
+  uint16_t check;
+  Addr     saddr;
+  Addr     daddr;
+};
+
+}
+}
+
+#endif
+

api/net/ip4/ip4.hpp

@@ -21,8 +21,9 @@
 #include <iostream>
 
 #include "addr.hpp"
+#include "header.hpp"
 #include <common>
-#include <net/ethernet.hpp>
+#include <net/ethernet/ethernet.hpp>
 #include <net/inet.hpp>
 
 namespace net {
@@ -34,48 +35,33 @@ namespace net {
   /** IP4 layer */
   class IP4 {
   public:
-    using addr = ip4::Addr;
+    using addr      = ip4::Addr;
+    using ip_header = ip4::Header;
 
     /** Initialize. Sets a dummy linklayer out. */
     explicit IP4(Inet<LinkLayer, IP4>&) noexcept;
 
     /** Known transport layer protocols. */
     enum proto { IP4_ICMP=1, IP4_UDP=17, IP4_TCP=6 };
 
-
-
     static const addr INADDR_ANY;
     static const addr INADDR_BCAST;
 
-    /** IP4 header representation */
-    struct ip_header {
-      uint8_t  version_ihl;
-      uint8_t  tos;
-      uint16_t tot_len;
-      uint16_t id;
-      uint16_t frag_off_flags;
-      uint8_t  ttl;
-      uint8_t  protocol;
-      uint16_t check;
-      addr     saddr;
-      addr     daddr;
-    };
-
     /**
      *  The full header including IP
      *
      *  @Note: This might be removed if we decide to isolate layers more
      */
     struct full_header {
-      uint8_t   link_hdr[sizeof(typename LinkLayer::header)];
-      ip_header ip_hdr;
+      uint8_t     link_hdr[sizeof(typename LinkLayer::header)];
+      ip4::Header ip_hdr;
     };
 
     /*
       Maximum Datagram Data Size
     */
     inline constexpr uint16_t MDDS() const
-    { return stack_.MTU() - sizeof(ip_header); }
+    { return stack_.MTU() - sizeof(ip4::Header); }
 
     /** Upstream: Input from link layer */
     void bottom(Packet_ptr);
@@ -107,7 +93,7 @@ namespace net {
     void transmit(Packet_ptr);
 
     /** Compute the IP4 header checksum */
-    uint16_t checksum(ip_header*);
+    uint16_t checksum(ip4::Header*);
 
     /**
      * \brief

src/net/ip4/ip4.cpp

@@ -17,7 +17,7 @@
 
 #define DEBUG // Allow debugging
 #define DEBUG2 // Allow debug lvl 2
-#include <os>
+
 #include <net/ip4/ip4.hpp>
 #include <net/ip4/packet_ip4.hpp>
 #include <net/packet.hpp>
@@ -41,12 +41,13 @@ namespace net {
 
   void IP4::bottom(Packet_ptr pckt) {
     debug2("<IP4 handler> got the data.\n");
+    // Cast to IP4 Packet
+    auto packet = std::static_pointer_cast<net::PacketIP4>(pckt);
 
     // Stat increment packets received
     packets_rx_++;
 
-    auto data = pckt->buffer();
-    ip_header* hdr = &reinterpret_cast<full_header*>(data)->ip_hdr;
+    ip_header* hdr = &packet->ip_header();
 
     // Drop if my ip address doesn't match destination ip address or broadcast
     if(UNLIKELY(hdr->daddr != local_ip() and
@@ -61,14 +62,14 @@ namespace net {
     switch(hdr->protocol){
     case IP4_ICMP:
       debug2("\t Type: ICMP\n");
-      icmp_handler_(pckt);
+      icmp_handler_(packet);
       break;
     case IP4_UDP:
       debug2("\t Type: UDP\n");
-      udp_handler_(pckt);
+      udp_handler_(packet);
       break;
     case IP4_TCP:
-      tcp_handler_(pckt);
+      tcp_handler_(packet);
       debug2("\t Type: TCP\n");
       break;
     default:
@@ -77,8 +78,8 @@ namespace net {
     }
   }
 
-  uint16_t IP4::checksum(ip_header* hdr) {
-    return net::checksum(reinterpret_cast<uint16_t*>(hdr), sizeof(ip_header));
+  uint16_t IP4::checksum(ip4::Header* hdr) {
+    return net::checksum(reinterpret_cast<uint16_t*>(hdr), sizeof(ip4::Header));
   }
 
   void IP4::transmit(Packet_ptr pckt) {