first prototype for the new Ethernet LLC/SNAP Packet

todo: add tests & documentation

Packets/DefaultBundle/EthernetPacket.cc

@@ -44,22 +44,41 @@ namespace {
 prefix_ void senf::EthernetPacketType::dump(packet p, std::ostream & os)
 {
     boost::io::ios_all_saver ias(os);
-    if (p->type() <= 1500)
+    if (p->type_length() <= 1500)
         os << "Ethernet 802.3";
-    else if (p->type() >= 0x600)
+    else if (p->type_length() >= 0x600)
         os << "Ethernet II (DIX)";
     else
         os << "Ethernet 802.3 (bad ethertype >1500 and <1536)";
     os << ": \n"
-       << "  destination   : " << p->destination() << "\n"
-       << "  source        : " << p->source() << "\n"
-       << "  ethertype     : 0x" 
-       << std::hex << std::setw(4) << std::setfill('0') << p->type() << "\n";
+       << "  destination : " << p->destination() << "\n"
+       << "  source      : " << p->source() << "\n"
+       << "  type/length : 0x" 
+       << std::hex << std::setw(4) << std::setfill('0') << p->type_length() << "\n";
+}
+
+prefix_ senf::PacketInterpreterBase::factory_t senf::EthernetPacketType::nextPacketType(packet p)
+{
+    if (p->type_length() >= 1536) {
+        PkReg_Entry const * e;
+        e = PacketRegistry<senf::EtherTypes>::lookup( p->type_length(), nothrow );
+        return e ? e->factory() : no_factory();
+    }
+    if (p->type_length() <= 1500)
+        return EthLlcSnapPacket::factory();
+    return no_factory();
 }
 
 prefix_ void senf::EthernetPacketType::finalize(packet p)
 {
-    p->type() << key(p.next());
+    optional_registry_key_t k = key(p.next());
+    if (k)
+        p->type_length() << k;
+    else
+        if (p.next().is<EthLlcSnapPacket>())
+            p->type_length() << p.next().data().size();
+        else
+            p->type_length() << 0;
 }
 
 prefix_ void senf::EthVLanPacketType::dump(packet p, std::ostream & os)
@@ -78,6 +97,25 @@ prefix_ void senf::EthVLanPacketType::finalize(packet p)
     p->type() << key(p.next());
 }
 
+prefix_ void senf::EthLlcSnapPacketType::dump(packet p, std::ostream & os)
+{
+    boost::io::ios_all_saver ias(os);
+    os << "Ethernet LLC/SNAP"
+       << "  LLC\n"
+       << "    DSAP: " << p->dsap() << "\n"
+       << "    SSAP: " << p->ssap() << "\n"
+       << "  SNAP\n"
+       << "    ProtocolId: " << p->protocolId() << "\n"
+       << "    type      : 0x" 
+       << std::hex << std::setw(4) << std::setfill('0') << p->type() << "\n";
+}
+
+prefix_ void senf::EthLlcSnapPacketType::finalize(packet p)
+{
+    p->type() << key(p.next());
+}
+
+
 ///////////////////////////////cc.e////////////////////////////////////////
 #undef prefix_
 

Packets/DefaultBundle/EthernetPacket.hh

@@ -72,7 +72,7 @@ namespace senf {
 
         SENF_PARSER_FIELD( destination, Parse_MAC    );
         SENF_PARSER_FIELD( source,      Parse_MAC    );
-        SENF_PARSER_FIELD( type,        Parse_UInt16 );
+        SENF_PARSER_FIELD( type_length, Parse_UInt16 );
 
         SENF_PARSER_FINALIZE(Parse_Ethernet);
     };
@@ -115,15 +115,11 @@ namespace senf {
         typedef Parse_Ethernet parser;
 #endif
         using mixin::nextPacketRange;
-        using mixin::nextPacketType;
+  //      using mixin::nextPacketType;
         using mixin::initSize;
         using mixin::init;
 
-        /** \todo Add LLC/SNAP support -> only use the registry
-            for type() values >=1536, otherwise expect an LLC header */
-        static registry_key_t nextPacketKey(packet p) 
-            { return p->type(); }
-
+        static factory_t nextPacketType(packet p);
         static void dump(packet p, std::ostream & os);
         static void finalize(packet p);
     };
@@ -191,6 +187,69 @@ namespace senf {
 
     /** \brief Ethernet VLAN tag typedef */
     typedef ConcretePacket<EthVLanPacketType> EthVLanPacket;
+
+
+    /** \brief Parse an ethernet LLC/SNAP header
+        
+        \todo document me
+
+        \see EthVLanPacketType
+     */
+    struct Parse_EthLlcSnapPacket : public PacketParserBase
+    {
+#       include SENF_FIXED_PARSER()
+
+        SENF_PARSER_FIELD( dsap, Parse_UInt8 );
+        SENF_PARSER_FIELD( ssap, Parse_UInt8 );
+        SENF_PARSER_FIELD( ctrl, Parse_UInt8 );
+
+        SENF_PARSER_FIELD( protocolId, Parse_UInt24 );
+        SENF_PARSER_FIELD( type, Parse_UInt24 );
+
+        SENF_PARSER_FINALIZE(Parse_EthLlcSnapPacket);
+    };
+
+    /** \brief Ethernet LLC/SNAP header
+
+        \todo document me
+
+        \par Packet type (typedef):
+            \ref EthLlcSnapPacketType
+
+        \par Fields:
+            \ref Parse_EthLlcSnapPacket
+
+        \par Associated registries:
+            \ref EtherTypes
+
+        \par Finalize action:
+            XXXX
+
+        \ingroup protocolbundle_default
+     */
+    struct EthLlcSnapPacketType
+        : public PacketTypeBase, 
+          public PacketTypeMixin<EthLlcSnapPacketType, EtherTypes>
+    {
+#ifndef DOXYGEN
+        typedef PacketTypeMixin<EthLlcSnapPacketType, EtherTypes> mixin;
+        typedef ConcretePacket<EthLlcSnapPacketType> packet;
+        typedef Parse_EthLlcSnapPacket parser;
+#endif
+        using mixin::nextPacketRange;
+        using mixin::nextPacketType;
+        using mixin::initSize;
+        using mixin::init;
+                
+        static registry_key_t nextPacketKey(packet p) 
+            { return p->type(); }
+
+        static void dump(packet p, std::ostream & os);
+        static void finalize(packet p);
+    };
+
+    /** \brief Ethernet VLAN tag typedef */
+    typedef ConcretePacket<EthLlcSnapPacketType> EthLlcSnapPacket;
 }
 
 

Packets/DefaultBundle/EthernetPacket.test.cc

@@ -45,7 +45,7 @@ BOOST_AUTO_UNIT_TEST(ethernetPacket_packet)
 
     BOOST_CHECK_EQUAL( p->destination()[3], 0x04 );
     BOOST_CHECK_EQUAL( p->source()[0], 0x07 );
-    BOOST_CHECK_EQUAL( p->type(), 0x1011 );
+    BOOST_CHECK_EQUAL( p->type_length(), 0x1011 );
 }
 
 BOOST_AUTO_UNIT_TEST(ethernetPacket_chain)
@@ -81,7 +81,7 @@ BOOST_AUTO_UNIT_TEST(ethernetPacket_create)
     vlan->vlanId() = 0x234u;
 
     eth.finalize();
-    BOOST_CHECK_EQUAL(eth->type(), 0x8100u);
+    BOOST_CHECK_EQUAL(eth->type_length(), 0x8100u);
     BOOST_CHECK_EQUAL(vlan->type(), 0u);
 
     senf::IpV4Packet ip (senf::IpV4Packet::createAfter(vlan));