Expand the 802.11 pseudo-header and support new radio metadata.

Add a set of presence bits, so we can indicate which bits of radio
metadata we do and don't have.

Fill in more radio metadata from capture files, and display it.

(More to come.)

Change-Id: Idea2c05442c74af17c14c4d5a8d8025ab27fbd15
Reviewed-on: https://code.wireshark.org/review/4987
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 95 insertions, 35 deletions

diff --git a/epan/dissectors/packet-ieee80211-radio.c b/epan/dissectors/packet-ieee80211-radio.c
index 9f8fe77cb9..b04c3ff32a 100644
--- a/epan/dissectors/packet-ieee80211-radio.c
+++ b/epan/dissectors/packet-ieee80211-radio.c
@@ -41,7 +41,11 @@ static int proto_radio = -1;
 /* ************************************************************************* */
 static int hf_data_rate = -1;
 static int hf_channel = -1;
-static int hf_signal_strength = -1;
+static int hf_frequency = -1;
+static int hf_signal_percent = -1;
+static int hf_signal_dbm = -1;
+static int hf_noise_percent = -1;
+static int hf_noise_dbm = -1;
 
 static gint ett_radio = -1;
 
@@ -59,42 +63,82 @@ dissect_radio (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
   col_clear(pinfo->cinfo, COL_INFO);
 
   /* Add the radio information to the column information */
-  col_add_fstr(pinfo->cinfo, COL_TX_RATE, "%u.%u",
-        pinfo->pseudo_header->ieee_802_11.data_rate / 2,
-        pinfo->pseudo_header->ieee_802_11.data_rate & 1 ? 5 : 0);
-  /*
-   * For tagged Peek files, this is presumably signal strength as a
-   * percentage of the maximum, as it is for classic Peek files,
-   * i.e. (RXVECTOR RSSI/RXVECTOR RSSI_Max)*100, or, at least, that's
-   * what I infer it is, given what the WildPackets note "Converting
-   * Signal Strength Percentage to dBm Values" says.
-   *
-   * It also says that the conversion the percentage to a dBm value is
-   * an adapter-dependent process, so, as we don't know what type of
-   * adapter was used to do the capture, we can't do the conversion.
-   *
-   * It's *probably* something similar for other capture file formats.
-   */
-  col_add_fstr(pinfo->cinfo, COL_RSSI, "%u%%",
-        pinfo->pseudo_header->ieee_802_11.signal_level);
+
+  if (pinfo->pseudo_header->ieee_802_11.presence_flags & PHDR_802_11_HAS_DATA_RATE) {
+      col_add_fstr(pinfo->cinfo, COL_TX_RATE, "%u.%u",
+            pinfo->pseudo_header->ieee_802_11.data_rate / 2,
+            pinfo->pseudo_header->ieee_802_11.data_rate & 1 ? 5 : 0);
+  }
+
+  if (pinfo->pseudo_header->ieee_802_11.presence_flags & PHDR_802_11_HAS_SIGNAL_PERCENT) {
+    /*
+     * For tagged Peek files, this is presumably signal strength as a
+     * percentage of the maximum, as it is for classic Peek files,
+     * i.e. (RXVECTOR RSSI/RXVECTOR RSSI_Max)*100, or, at least, that's
+     * what I infer it is, given what the WildPackets note "Converting
+     * Signal Strength Percentage to dBm Values" says.
+     *
+     * It also says that the conversion the percentage to a dBm value is
+     * an adapter-dependent process, so, as we don't know what type of
+     * adapter was used to do the capture, we can't do the conversion.
+     *
+     * It's *probably* something similar for other capture file formats.
+     */
+    col_add_fstr(pinfo->cinfo, COL_RSSI, "%u%%",
+          pinfo->pseudo_header->ieee_802_11.signal_percent);
+  }
 
   if (tree) {
     ti = proto_tree_add_item(tree, proto_radio, tvb, 0, 0, ENC_NA);
     radio_tree = proto_item_add_subtree (ti, ett_radio);
 
-    proto_tree_add_uint64_format_value(radio_tree, hf_data_rate, tvb, 0, 0,
-             (guint64)pinfo->pseudo_header->ieee_802_11.data_rate * 500000,
-             "%u.%u Mb/s",
-             pinfo->pseudo_header->ieee_802_11.data_rate / 2,
-             pinfo->pseudo_header->ieee_802_11.data_rate & 1 ? 5 : 0);
-
-    proto_tree_add_uint(radio_tree, hf_channel, tvb, 0, 0,
-            pinfo->pseudo_header->ieee_802_11.channel);
-
-    proto_tree_add_uint_format_value(radio_tree, hf_signal_strength, tvb, 0, 0,
-            pinfo->pseudo_header->ieee_802_11.signal_level,
-            "%u%%",
-            pinfo->pseudo_header->ieee_802_11.signal_level);
+    if (pinfo->pseudo_header->ieee_802_11.presence_flags & PHDR_802_11_HAS_DATA_RATE) {
+      proto_tree_add_uint64_format_value(radio_tree, hf_data_rate, tvb, 0, 0,
+               (guint64)pinfo->pseudo_header->ieee_802_11.data_rate * 500000,
+               "%u.%u Mb/s",
+               pinfo->pseudo_header->ieee_802_11.data_rate / 2,
+               pinfo->pseudo_header->ieee_802_11.data_rate & 1 ? 5 : 0);
+    }
+
+    if (pinfo->pseudo_header->ieee_802_11.presence_flags & PHDR_802_11_HAS_CHANNEL) {
+      proto_tree_add_uint(radio_tree, hf_channel, tvb, 0, 0,
+              pinfo->pseudo_header->ieee_802_11.channel);
+    }
+
+    if (pinfo->pseudo_header->ieee_802_11.presence_flags & PHDR_802_11_HAS_FREQUENCY) {
+      proto_tree_add_uint_format_value(radio_tree, hf_frequency, tvb, 0, 0,
+              pinfo->pseudo_header->ieee_802_11.frequency,
+              "%u MHz",
+              pinfo->pseudo_header->ieee_802_11.frequency);
+    }
+
+    if (pinfo->pseudo_header->ieee_802_11.presence_flags & PHDR_802_11_HAS_SIGNAL_PERCENT) {
+      proto_tree_add_uint_format_value(radio_tree, hf_signal_percent, tvb, 0, 0,
+              pinfo->pseudo_header->ieee_802_11.signal_percent,
+              "%u%%",
+              pinfo->pseudo_header->ieee_802_11.signal_percent);
+    }
+
+    if (pinfo->pseudo_header->ieee_802_11.presence_flags & PHDR_802_11_HAS_SIGNAL_DBM) {
+      proto_tree_add_int_format_value(radio_tree, hf_signal_dbm, tvb, 0, 0,
+              pinfo->pseudo_header->ieee_802_11.signal_dbm,
+              "%d dBm",
+              pinfo->pseudo_header->ieee_802_11.signal_dbm);
+    }
+
+    if (pinfo->pseudo_header->ieee_802_11.presence_flags & PHDR_802_11_HAS_NOISE_PERCENT) {
+      proto_tree_add_uint_format_value(radio_tree, hf_noise_percent, tvb, 0, 0,
+              pinfo->pseudo_header->ieee_802_11.noise_percent,
+              "%u%%",
+              pinfo->pseudo_header->ieee_802_11.noise_percent);
+    }
+
+    if (pinfo->pseudo_header->ieee_802_11.presence_flags & PHDR_802_11_HAS_NOISE_DBM) {
+      proto_tree_add_int_format_value(radio_tree, hf_noise_dbm, tvb, 0, 0,
+              pinfo->pseudo_header->ieee_802_11.noise_dbm,
+              "%d dBm",
+              pinfo->pseudo_header->ieee_802_11.noise_dbm);
+    }
   }
 
   /* dissect the 802.11 header next */
@@ -111,9 +155,25 @@ static hf_register_info hf_radio[] = {
      {"Channel", "wlan.channel", FT_UINT8, BASE_DEC, NULL, 0,
       "802.11 channel number that this frame was sent/received on", HFILL }},
 
-    {&hf_signal_strength,
-     {"Signal Strength", "wlan.signal_strength", FT_UINT8, BASE_DEC, NULL, 0,
-      "Signal strength (Percentage)", HFILL }}
+    {&hf_frequency,
+     {"Frequency", "wlan.frequency", FT_UINT16, BASE_DEC, NULL, 0,
+      "Center frequency of the 802.11 channel that this frame was sent/received on", HFILL }},
+
+    {&hf_signal_percent,
+     {"Signal Strength (Percentage)", "wlan.signal_dbm", FT_UINT8, BASE_DEC, NULL, 0,
+      "Signal strength (Percentage)", HFILL }},
+
+    {&hf_signal_dbm,
+     {"Signal Strength (dBm)", "wlan.signal_dbm", FT_INT8, BASE_DEC, NULL, 0,
+      "Signal strength (dBm)", HFILL }},
+
+    {&hf_noise_percent,
+     {"Noise Level (Percentage)", "wlan.noise_percentage", FT_UINT8, BASE_DEC, NULL, 0,
+      "Noise Level (Percentage)", HFILL }},
+
+    {&hf_noise_dbm,
+     {"Noise Level (dBm)", "wlan.noise_dbm", FT_INT8, BASE_DEC, NULL, 0,
+      "Noise Level (dBm)", HFILL }},
 };
 
 static gint *tree_array[] = {