It appears that some fields in the Prism header might have a DID value

of 0, and that appears to mean that they're not present.  Check for
that, as well as the status.

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@23914 f5534014-38df-0310-8fa8-9805f1628bb7

diff --git a/epan/dissectors/packet-ieee80211.c b/epan/dissectors/packet-ieee80211.c
index b28ea83db7b6284ffc28115bc94c7f198b7aa037..9ca9b5b7ad98660d1ab504bd76a6fd7f5d9b4405 100644 (file)
--- a/epan/dissectors/packet-ieee80211.c
+++ b/epan/dissectors/packet-ieee80211.c
@@ -7166,6 +7166,7 @@ wlan_retransmit_init(void)
  * below more readable
  * XXX - This should be rewritten to use ptvcursors, then.
  */
+#define FIELD_PRESENT(name)    (hdr.name.status == 0 && hdr.name.did != 0)
 #define IFHELP(size, name, var, str) \
         if(tree) {                                               \
             proto_tree_add_uint_format(prism_tree, hf_prism_ ## name, \
@@ -7174,7 +7175,7 @@ wlan_retransmit_init(void)
         offset += (size)
 #define INTFIELD(size, name, str)      IFHELP(size, name, name, str)
 #define VALFIELD(name, str) \
-        if (hdr.name.status == 0) {                                    \
+        if (FIELD_PRESENT(name)) {                                     \
             if(tree) {                                                 \
                 proto_tree_add_uint_format(prism_tree, hf_ ## name,    \
                     tvb, offset, 12, hdr.name.data,                    \
@@ -7185,7 +7186,7 @@ wlan_retransmit_init(void)
         }                                                              \
         offset += 12
 #define VALFIELD_PRISM(name, str) \
-        if (hdr.name.status == 0) {                              \
+        if (FIELD_PRESENT(name)) {                                     \
             if(tree) {                                           \
                 proto_tree_add_uint_format(prism_tree, hf_prism_ ## name ## _data, \
                     tvb, offset, 12, hdr.name.data,                       \
@@ -7241,7 +7242,7 @@ dissect_prism(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     }
     offset += sizeof hdr.devname;
 
-    if (hdr.hosttime.status == 0) {
+    if (FIELD_PRESENT(hosttime)) {
       if(tree) {
         proto_tree_add_uint64_format(prism_tree, hf_hosttime,
             tvb, offset, 12, hdr.hosttime.data,
@@ -7251,7 +7252,7 @@ dissect_prism(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
       }
     }
     offset += 12;
-    if (hdr.mactime.status == 0) {
+    if (FIELD_PRESENT(mactime)) {
       if(tree) {
         proto_tree_add_uint64_format(prism_tree, hf_mactime,
             tvb, offset, 12, hdr.mactime.data,
@@ -7261,12 +7262,12 @@ dissect_prism(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
       }
     }
     offset += 12;
-    if (hdr.channel.status == 0) {
+    if (FIELD_PRESENT(channel)) {
       if (check_col(pinfo->cinfo, COL_FREQ_CHAN))
         col_add_fstr(pinfo->cinfo, COL_FREQ_CHAN, "%u", hdr.channel.data);
     }
     VALFIELD(channel, "Channel");
-    if (hdr.rssi.status == 0) {
+    if (FIELD_PRESENT(rssi)) {
       if (check_col(pinfo->cinfo, COL_RSSI))
         col_add_fstr(pinfo->cinfo, COL_RSSI, "%d", hdr.rssi.data);
       if (tree) {
@@ -7280,7 +7281,7 @@ dissect_prism(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     VALFIELD_PRISM(sq, "SQ");
     VALFIELD_PRISM(signal, "Signal");
     VALFIELD_PRISM(noise, "Noise");
-    if (hdr.rate.status == 0) {
+    if (FIELD_PRESENT(rate)) {
       if (check_col(pinfo->cinfo, COL_TX_RATE)) {
         col_add_fstr(pinfo->cinfo, COL_TX_RATE, "%u.%u",
                   hdr.rate.data / 2, hdr.rate.data & 1 ? 5 : 0);