--- a/src/devices/mesh/dot11s/peer-link-frame.cc	Tue Jun 22 11:50:55 2010 +0100
+++ b/src/devices/mesh/dot11s/peer-link-frame.cc	Tue Jun 22 11:59:26 2010 +0100
@@ -140,10 +140,7 @@
 {
   Buffer::Iterator i = start;
   NS_ASSERT (m_subtype < 3);
-  i.WriteU8 (IE11S_MESH_PEERING_PROTOCOL_VERSION);
-  i.WriteU8 (m_protocol.GetInformationSize ());
-  m_protocol.SerializeInformation (i);
-  i.Next (m_protocol.GetInformationSize ());
+  i = m_protocol.SerializeIE (i);
   if ((uint8_t) (WifiActionHeader::PEER_LINK_CLOSE) != m_subtype)
     {
       i.WriteHtolsbU16 (m_capability);
@@ -158,17 +155,11 @@
     }
   if ((uint8_t) (WifiActionHeader::PEER_LINK_CONFIRM) != m_subtype)
     {
-      i.WriteU8 (IE11S_MESH_ID);
-      i.WriteU8 (m_meshId.GetInformationSize ());
-      m_meshId.SerializeInformation (i);
-      i.Next (m_meshId.GetInformationSize ());
+      i = m_meshId.SerializeIE (i);
     }
   if ((uint8_t) (WifiActionHeader::PEER_LINK_CLOSE) != m_subtype)
     {
-      i.WriteU8 (IE11S_MESH_CONFIGURATION);
-      i.WriteU8 (m_config.GetInformationSize ());
-      m_config.SerializeInformation (i);
-      i.Next (m_config.GetInformationSize ());
+      i = m_config.SerializeIE (i);
     }
   else
     {

--- a/src/devices/wifi/wifi-information-element-vector.cc	Tue Jun 22 11:50:55 2010 +0100
+++ b/src/devices/wifi/wifi-information-element-vector.cc	Tue Jun 22 11:59:26 2010 +0100
@@ -59,10 +59,7 @@
 {
   for(IE_VECTOR::const_iterator i = m_elements.begin (); i != m_elements.end (); i ++)
     {
-      start.WriteU8((*i)->ElementId ());
-      start.WriteU8 ((*i)->GetInformationSize ());
-      (*i)->SerializeInformation (start);
-      start.Next ((*i)->GetInformationSize ());
+      start = (*i)->SerializeIE (start);
     }
 }
 uint32_t

--- a/src/devices/wifi/wifi-information-element.cc	Tue Jun 22 11:50:55 2010 +0100
+++ b/src/devices/wifi/wifi-information-element.cc	Tue Jun 22 11:59:26 2010 +0100
@@ -25,6 +25,60 @@
 WifiInformationElement::~WifiInformationElement ()
 {}
 
+void
+WifiInformationElement::Print (std::ostream &os) const
+{}
+
+uint16_t
+WifiInformationElement::GetSerializedSize () const
+{
+  return (2 + GetInformationSize ());
+}
+  
+Buffer::Iterator
+WifiInformationElement::SerializeIE (Buffer::Iterator i) const
+{
+  i.WriteU8 (ElementId ());
+  i.WriteU8 (GetInformationSize ());
+  SerializeInformation (i);
+  i.Next (GetInformationSize ());
+  return i;
+}
+
+Buffer::Iterator
+WifiInformationElement::DeserializeIE (Buffer::Iterator i)
+{
+  Buffer::Iterator start = i;
+  i = DeserializeOptionalIE (i);
+  // This IE was not optional, so confirm that we did actually
+  // deserialise something.
+  NS_ASSERT (i.GetDistanceFrom (start) != 0);
+  return i;
+}
+
+Buffer::Iterator
+WifiInformationElement::DeserializeOptionalIE (Buffer::Iterator i)
+{
+  Buffer::Iterator start = i;
+  uint8_t elementId = i.ReadU8 ();
+
+  // If the element here isn't the one we're after then we immediately
+  // return the iterator we were passed indicating that we haven't
+  // taken anything from the buffer.
+  if (elementId != ElementId ())
+    {
+      return start;
+    }
+
+  uint8_t length = i.ReadU8 ();
+
+  DeserializeInformation (i, length);
+  i.Next (length);
+
+  return i;
+}
+
+
 bool
 WifiInformationElement::operator< (WifiInformationElement const & a) const
 {

--- a/src/devices/wifi/wifi-information-element.h	Tue Jun 22 11:50:55 2010 +0100
+++ b/src/devices/wifi/wifi-information-element.h	Tue Jun 22 11:59:26 2010 +0100
@@ -136,25 +136,50 @@
 {
 public:
   virtual ~WifiInformationElement ();
+  /// Serialize entire IE including Element ID and length fields
+  Buffer::Iterator SerializeIE (Buffer::Iterator i) const;
+  /// Deserialize entire IE, which must be present. The iterator
+  /// passed in must be pointing at the Element ID (i.e., the very
+  /// first octet) of the correct type of information element,
+  /// otherwise this method will generate a fatal error.
+  Buffer::Iterator DeserializeIE (Buffer::Iterator i);
+  /// Deserialize entire IE if it is present. The iterator passed in
+  /// must be pointing at the Element ID of an information element. If
+  /// the Element ID is not the one that the given class is interested
+  /// in then it will return the same iterator.
+  Buffer::Iterator DeserializeOptionalIE (Buffer::Iterator i);
+  /// Get the size of the serialized IE including Element ID and
+  /// length fields.
+  uint16_t GetSerializedSize () const;
+
   ///\name Each subclass must implement
   //\{
-  virtual void Print (std::ostream &os) const = 0;
   /// Own unique Element ID
   virtual WifiInformationElementId ElementId () const = 0;
-  /// Length of serialized information
+  /// Length of serialized information (i.e., the length of the body
+  /// of the IE, not including the Element ID and length octets. This
+  /// is the value that will appear in the second octet of the entire
+  /// IE - the length field)
   virtual uint8_t GetInformationSize () const = 0;
-  /// Serialize information
+  /// Serialize information (i.e., the body of the IE, not including
+  /// the Element ID and length octets)
   virtual void SerializeInformation (Buffer::Iterator start) const = 0;
-  /// Deserialize information
+  /// Deserialize information (i.e., the body of the IE, not including
+  /// the Element ID and length octets)
   virtual uint8_t DeserializeInformation (Buffer::Iterator start,
                                           uint8_t length) = 0;
   //\}
 
+  /// In addition, a subclass may optionally override the following...
+  //\{
+  /// Generate human-readable form of IE
+  virtual void Print (std::ostream &os) const;
   /// Compare information elements using Element ID
   virtual bool operator< (WifiInformationElement const & a) const;
   /// Compare two IEs for equality by ID & Length, and then through
   /// memcmp of serialised version
   virtual bool operator== (WifiInformationElement const & a) const;
+  //\}
 };
 
 }