add wifi pcap output

src/common/pcap-writer.cc

@@ -35,6 +35,7 @@ namespace ns3 {
 enum {
   PCAP_ETHERNET = 1,
   PCAP_RAW_IP   = 101,
+  PCAP_80211    = 105,
 };
 
 PcapWriter::PcapWriter ()
@@ -65,6 +66,12 @@ PcapWriter::WriteIpHeader (void)
   WriteHeader (PCAP_RAW_IP);
 }
 
+void
+PcapWriter::WriteWifiHeader (void)
+{
+  WriteHeader (PCAP_80211);
+}
+
 void 
 PcapWriter::WriteHeader (uint32_t network)
 {

src/common/pcap-writer.h

@@ -59,6 +59,8 @@ public:
 
   void WriteIpHeader (void);
 
+  void WriteWifiHeader (void);
+
   /**
    * \param packet packet to write to output file
    */