From a85b2c76cdff2a82975ee53429de6992370dfc84 Mon Sep 17 00:00:00 2001
From: pdw <>
Date: Mon, 3 Oct 2011 21:46:35 +0000
Subject: [PATCH] Untested radiotap support.

---
 configure.in |  2 +-
 ether.h      | 10 ++++++++++
 iftop.c      | 31 +++++++++++++++++++++++++++----
 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/configure.in b/configure.in
index 2aee6e3..abc3138 100644
--- a/configure.in
+++ b/configure.in
@@ -29,7 +29,7 @@ AC_CONFIG_AUX_DIR(config)
 AC_CANONICAL_SYSTEM
 
 AM_CONFIG_HEADER(config.h)
-AM_INIT_AUTOMAKE(iftop, "1.0pre1")
+AM_INIT_AUTOMAKE(iftop, "1.0pre2")
 
 AC_DEFINE_UNQUOTED(IFTOP_VERSION, "$VERSION", [The iftop version number])
 
diff --git a/ether.h b/ether.h
index 6da3673..26caf9b 100644
--- a/ether.h
+++ b/ether.h
@@ -20,4 +20,14 @@ struct vlan_8021q_header {
 	u_int16_t	ether_type;
 };
 
+/*
+ * http://www.gsp.com/cgi-bin/man.cgi?section=9&topic=ieee80211_radiotap
+ */
+struct radiotap_header {
+        u_int8_t        it_version;     /* set to 0 */
+        u_int8_t        it_pad;
+        u_int16_t       it_len;         /* entire length */
+        u_int32_t       it_present;     /* fields present */
+};
+
 #endif 
diff --git a/iftop.c b/iftop.c
index a604350..43329f8 100644
--- a/iftop.c
+++ b/iftop.c
@@ -81,8 +81,12 @@ static void finish(int sig) {
 
 
 
-/* Only need ethernet (plus optional 4 byte VLAN) and IP headers (48) + first 2 bytes of tcp/udp header */
+/* Only need ethernet (plus optional 4 byte VLAN) and IP headers (48) + first 2
+ * bytes of tcp/udp header */
 /* Increase with a further 20 to account for IPv6 header length.  */
+/* IEEE 802.11 radiotap throws in a variable length header plus 8 (radiotap
+ * header header) plus 30 (802.11 MAC) plus 40 (IPv6) = 78, plus whatever's in
+ * the radiotap payload */
 #define CAPTURE_LENGTH 92
 
 void init_history() {
@@ -230,8 +234,8 @@ static void handle_ip_packet(struct ip* iptr, int hw_dir)
     int direction = 0; /* incoming */
     history_type* ht;
     union {
-	history_type **ht_pp;
-	void **void_pp;
+      history_type **ht_pp;
+      void **void_pp;
     } u_ht = { &ht };
     addr_pair ap;
     unsigned int len = 0;
@@ -446,7 +450,7 @@ static void handle_pflog_packet(unsigned char* args, const struct pcap_pkthdr* p
 	hdrlen = BPF_WORDALIGN(hdr->length);
 	length -= hdrlen;
 	packet += hdrlen;
-	handle_ip_packet((struct ip*)packet, length);
+	handle_ip_packet((struct ip*)packet, -1);
 }
 #endif
 
@@ -600,6 +604,20 @@ static void handle_eth_packet(unsigned char* args, const struct pcap_pkthdr* pkt
     }
 }
 
+#ifdef DLT_IEEE802_11_RADIO
+/*
+ * Packets with a bonus radiotap header.
+ * See http://www.gsp.com/cgi-bin/man.cgi?section=9&topic=ieee80211_radiotap
+ */
+static void handle_radiotap_packet(unsigned char* args, const struct pcap_pkthdr* pkthdr, const unsigned char* packet)
+{
+    /* 802.11 MAC header is = 30 bytes */
+    /* We could try harder to figure out hardware direction from the MAC header */
+    handle_ip_packet((struct ip*)(packet + ((struct radiotap_header *)packet)->it_len + 30),-1);
+}
+
+
+#endif
 
 /* set_filter_code:
  * Install some filter code. Returns NULL on success or an error message on
@@ -698,6 +716,11 @@ void packet_init() {
     else if(dlt == DLT_LOOP) {
         packet_handler = handle_null_packet;
     }
+#endif
+#ifdef DLT_IEEE802_11_RADIO
+    else if(dlt == DLT_IEEE802_11_RADIO) {
+        packet_handler = handle_radiotap_packet;
+    }
 #endif
     else if(dlt == DLT_IEEE802) {
         packet_handler = handle_tokenring_packet;