packet-ieee80211-radio.c: Minor refactor and whitespace cleanup

Change-Id: Idad8f7eeed968eeed9f553fef98d58453f328afb
Reviewed-on: https://code.wireshark.org/review/21421
Petri-Dish: Michael Mann <mmann78@netscape.net>
Reviewed-by: Michael Mann <mmann78@netscape.net>
Tested-by: Michael Mann <mmann78@netscape.net>

2 files changed, 317 insertions, 325 deletions

diff --git a/epan/dissectors/packet-ieee80211-radio.c b/epan/dissectors/packet-ieee80211-radio.c
index 5b847b38e5..ebe72fea5b 100644
--- a/epan/dissectors/packet-ieee80211-radio.c
+++ b/epan/dissectors/packet-ieee80211-radio.c
@@ -175,30 +175,30 @@ static const value_string fec_vals[] = {
  * Note: MCS 32 is special - only valid for 40Mhz channel.
  */
 WS_DLL_PUBLIC_DEF const guint16 ieee80211_ht_Dbps[MAX_MCS_INDEX+1] = {
-	/* MCS  0 - 1 stream */
-	26, 52, 78, 104, 156, 208, 234, 260,
+    /* MCS  0 - 1 stream */
+    26, 52, 78, 104, 156, 208, 234, 260,
 
-	/* MCS  8 - 2 stream */
-	52, 104, 156, 208, 312, 416, 468, 520,
+    /* MCS  8 - 2 stream */
+    52, 104, 156, 208, 312, 416, 468, 520,
 
-	/* MCS 16 - 3 stream */
-	78, 156, 234, 312, 468, 624, 702, 780,
+    /* MCS 16 - 3 stream */
+    78, 156, 234, 312, 468, 624, 702, 780,
 
-	/* MCS 24 - 4 stream */
-	104, 208, 312, 416, 624, 832, 936, 1040,
+    /* MCS 24 - 4 stream */
+    104, 208, 312, 416, 624, 832, 936, 1040,
 
-	/* MCS 32 - 1 stream */
-	12, /* only valid for 40Mhz - 11a/g DUP mode */
+    /* MCS 32 - 1 stream */
+    12, /* only valid for 40Mhz - 11a/g DUP mode */
 
-	/* MCS 33 - 2 stream */
-	156, 208, 260, 234, 312, 390,
+    /* MCS 33 - 2 stream */
+    156, 208, 260, 234, 312, 390,
 
-	/* MCS 39 - 3 stream */
-	208, 260, 260, 312, 364, 364, 416, 312, 390, 390, 468, 546, 546, 624,
+    /* MCS 39 - 3 stream */
+    208, 260, 260, 312, 364, 364, 416, 312, 390, 390, 468, 546, 546, 624,
 
-	/* MCS 53 - 4 stream */
-	260, 312, 364, 312, 364, 416, 468, 416, 468, 520, 520, 572,
-	390, 468, 546, 468, 546, 624, 702, 624, 702, 780, 780, 858
+    /* MCS 53 - 4 stream */
+    260, 312, 364, 312, 364, 416, 468, 416, 468, 520, 520, 572,
+    390, 468, 546, 468, 546, 624, 702, 624, 702, 780, 780, 858
 };
 
 /*
@@ -379,12 +379,15 @@ static void
 dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void *data)
 {
   struct ieee_802_11_phdr *phdr = (struct ieee_802_11_phdr *)data;
-  proto_item *ti = NULL;
-  proto_tree *radio_tree = NULL;
+  proto_item *ti;
+  proto_tree *radio_tree;
   float data_rate = 0.0f;
   gboolean have_data_rate = FALSE;
   gboolean has_short_preamble = FALSE;
   gboolean short_preamble = 1;
+  guint bandwidth = 0;
+  gboolean can_calculate_rate = FALSE;
+  proto_item *p_item;
 
   guint frame_length = tvb_reported_length(tvb); /* length of 802.11 frame data */
 
@@ -392,6 +395,9 @@ dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
   guint preamble = 0; /* duration of plcp */
   guint duration = 0; /* duration of whole frame (plcp + mac data + any trailing parts) */
 
+  int phy = phdr->phy;
+  union ieee_802_11_phy_info *phy_info = &phdr->phy_info;
+
   col_set_str(pinfo->cinfo, COL_PROTOCOL, "Radio");
   col_clear(pinfo->cinfo, COL_INFO);
 
@@ -407,19 +413,17 @@ dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
     col_add_fstr(pinfo->cinfo, COL_RSSI, "%u%%", phdr->signal_percent);
   }
 
-  if (tree) {
-    ti = proto_tree_add_item(tree, proto_wlan_radio, tvb, 0, 0, ENC_NA);
-    radio_tree = proto_item_add_subtree (ti, ett_wlan_radio);
+  ti = proto_tree_add_item(tree, proto_wlan_radio, tvb, 0, 0, ENC_NA);
+  radio_tree = proto_item_add_subtree (ti, ett_wlan_radio);
 
-    if (phdr->phy != PHDR_802_11_PHY_UNKNOWN) {
-      proto_tree_add_uint(radio_tree, hf_wlan_radio_phy, tvb, 0, 0,
-               phdr->phy);
+  if (phy != PHDR_802_11_PHY_UNKNOWN) {
+    proto_tree_add_uint(radio_tree, hf_wlan_radio_phy, tvb, 0, 0, phy);
 
-      switch (phdr->phy) {
+    switch (phy) {
 
       case PHDR_802_11_PHY_11_FHSS:
       {
-        struct ieee_802_11_fhss *info_fhss = &phdr->phy_info.info_11_fhss;
+        struct ieee_802_11_fhss *info_fhss = &phy_info->info_11_fhss;
 
         if (info_fhss->has_hop_set) {
           proto_tree_add_uint(radio_tree, hf_wlan_radio_11_fhss_hop_set, tvb, 0, 0,
@@ -438,7 +442,7 @@ dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
 
       case PHDR_802_11_PHY_11B:
       {
-        struct ieee_802_11b *info_b = &phdr->phy_info.info_11b;
+        struct ieee_802_11b *info_b = &phy_info->info_11b;
 
         has_short_preamble = info_b->has_short_preamble;
         short_preamble = info_b->short_preamble;
@@ -452,7 +456,7 @@ dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
 
       case PHDR_802_11_PHY_11A:
       {
-        struct ieee_802_11a *info_a = &phdr->phy_info.info_11a;
+        struct ieee_802_11a *info_a = &phy_info->info_11a;
 
         if (info_a->has_channel_type) {
           proto_tree_add_uint(radio_tree, hf_wlan_radio_11a_channel_type, tvb, 0, 0,
@@ -467,7 +471,7 @@ dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
 
       case PHDR_802_11_PHY_11G:
       {
-        struct ieee_802_11g *info_g = &phdr->phy_info.info_11g;
+        struct ieee_802_11g *info_g = &phy_info->info_11g;
 
         has_short_preamble = info_g->has_short_preamble;
         short_preamble = info_g->short_preamble;
@@ -485,9 +489,23 @@ dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
 
       case PHDR_802_11_PHY_11N:
         {
-          struct ieee_802_11n *info_n = &phdr->phy_info.info_11n;
+          struct ieee_802_11n *info_n = &phy_info->info_11n;
           guint bandwidth_40;
 
+          /*
+           * If we have all the fields needed to look up the data rate,
+           * do so.
+           */
+          if (info_n->has_mcs_index &&
+              info_n->has_bandwidth &&
+              info_n->has_short_gi) {
+            bandwidth_40 = (info_n->bandwidth == PHDR_802_11_BANDWIDTH_40_MHZ) ? 1 : 0;
+            if (info_n->mcs_index < MAX_MCS_INDEX) {
+              data_rate = ieee80211_htrate(info_n->mcs_index, bandwidth_40, info_n->short_gi);
+              have_data_rate = TRUE;
+            }
+          }
+
           if (info_n->has_mcs_index) {
             proto_tree_add_uint(radio_tree, hf_wlan_radio_11n_mcs_index, tvb, 0, 0,
                      info_n->mcs_index);
@@ -522,32 +540,44 @@ dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
             proto_tree_add_uint(radio_tree, hf_wlan_radio_11n_ness, tvb, 0, 0,
                      info_n->ness);
           }
-
-          /*
-           * If we have all the fields needed to look up the data rate,
-           * do so.
-           */
-          if (info_n->has_mcs_index &&
-              info_n->has_bandwidth &&
-              info_n->has_short_gi) {
-            bandwidth_40 =
-              (info_n->bandwidth == PHDR_802_11_BANDWIDTH_40_MHZ) ?
-               1 : 0;
-            if (info_n->mcs_index <= MAX_MCS_INDEX) {
-              data_rate = ieee80211_htrate(info_n->mcs_index, bandwidth_40, info_n->short_gi);
-              have_data_rate = TRUE;
-            }
-          }
         }
         break;
 
       case PHDR_802_11_PHY_11AC:
         {
-          struct ieee_802_11ac *info_ac = &phdr->phy_info.info_11ac;
-          gboolean can_calculate_rate;
-          guint bandwidth = 0;
+          struct ieee_802_11ac *info_ac = &phy_info->info_11ac;
           guint i;
 
+          if (info_ac->has_short_gi) {
+            can_calculate_rate = TRUE;  /* well, if we also have the bandwidth */
+            proto_tree_add_boolean(radio_tree, hf_wlan_radio_11ac_short_gi, tvb, 0, 0, info_ac->short_gi);
+          } else {
+            can_calculate_rate = FALSE; /* unknown GI length */
+          }
+
+          if (info_ac->has_bandwidth) {
+            proto_tree_add_uint(radio_tree, hf_wlan_radio_11ac_bandwidth, tvb, 0, 0, info_ac->bandwidth);
+            if (info_ac->bandwidth < G_N_ELEMENTS(ieee80211_vht_bw2rate_index))
+              bandwidth = ieee80211_vht_bw2rate_index[info_ac->bandwidth];
+            else
+              can_calculate_rate = FALSE; /* unknown bandwidth */
+          } else {
+            can_calculate_rate = FALSE;   /* no bandwidth */
+          }
+
+          for (i = 0; i < 4; i++) {
+
+            if (info_ac->nss[i] != 0) {
+              /*
+               * If we can calculate the data rate for this user, do so.
+               */
+              if (can_calculate_rate && info_ac->mcs[i] <= MAX_MCS_VHT_INDEX) {
+                data_rate = ieee80211_vhtrate(info_ac->mcs[i], bandwidth, info_ac->short_gi) * info_ac->nss[i];
+                have_data_rate = TRUE;
+              }
+            }
+          }
+
           if (info_ac->has_stbc) {
             proto_tree_add_boolean(radio_tree, hf_wlan_radio_11ac_stbc, tvb, 0, 0,
                      info_ac->stbc);
@@ -558,14 +588,6 @@ dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
                      info_ac->txop_ps_not_allowed);
           }
 
-          if (info_ac->has_short_gi) {
-            can_calculate_rate = TRUE;  /* well, if we also have the bandwidth */
-            proto_tree_add_boolean(radio_tree, hf_wlan_radio_11ac_short_gi, tvb, 0, 0,
-                     info_ac->short_gi);
-          } else {
-            can_calculate_rate = FALSE; /* unknown GI length */
-          }
-
           if (info_ac->has_short_gi_nsym_disambig) {
             proto_tree_add_boolean(radio_tree, hf_wlan_radio_11ac_short_gi_nsym_disambig, tvb, 0, 0,
                      info_ac->short_gi_nsym_disambig);
@@ -581,17 +603,6 @@ dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
                      info_ac->beamformed);
           }
 
-          if (info_ac->has_bandwidth) {
-            if (info_ac->bandwidth < G_N_ELEMENTS(ieee80211_vht_bw2rate_index))
-              bandwidth = ieee80211_vht_bw2rate_index[info_ac->bandwidth];
-            else
-              can_calculate_rate = FALSE; /* unknown bandwidth */
-            proto_tree_add_uint(radio_tree, hf_wlan_radio_11ac_bandwidth, tvb, 0, 0,
-                     info_ac->bandwidth);
-          } else {
-            can_calculate_rate = FALSE;   /* no bandwidth */
-          }
-
           for (i = 0; i < 4; i++) {
 
             if (info_ac->nss[i] != 0) {
@@ -661,267 +672,249 @@ dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
           }
         }
         break;
-      }
     }
+  }
 
-    if (have_data_rate) {
-      col_add_fstr(pinfo->cinfo, COL_TX_RATE, "%.1f", data_rate);
-      proto_tree_add_float_format_value(radio_tree, hf_wlan_radio_data_rate, tvb, 0, 0,
+  if (have_data_rate) {
+    col_add_fstr(pinfo->cinfo, COL_TX_RATE, "%.1f", data_rate);
+    proto_tree_add_float_format_value(radio_tree, hf_wlan_radio_data_rate, tvb, 0, 0,
                data_rate,
                "%.1f Mb/s",
                data_rate);
-    }
+  }
 
-    if (phdr->has_channel) {
-      col_add_fstr(pinfo->cinfo, COL_FREQ_CHAN, "%u", phdr->channel);
-      proto_tree_add_uint(radio_tree, hf_wlan_radio_channel, tvb, 0, 0,
-              phdr->channel);
-    }
+  if (phdr->has_channel) {
+    col_add_fstr(pinfo->cinfo, COL_FREQ_CHAN, "%u", phdr->channel);
+    proto_tree_add_uint(radio_tree, hf_wlan_radio_channel, tvb, 0, 0, phdr->channel);
+  }
 
-    if (phdr->has_frequency) {
-      col_add_fstr(pinfo->cinfo, COL_FREQ_CHAN, "%u MHz", phdr->frequency);
-      proto_tree_add_uint_format_value(radio_tree, hf_wlan_radio_frequency, tvb, 0, 0,
-              phdr->frequency,
-              "%u MHz",
-              phdr->frequency);
-    }
+  if (phdr->has_frequency) {
+    col_add_fstr(pinfo->cinfo, COL_FREQ_CHAN, "%u MHz", phdr->frequency);
+    proto_tree_add_uint(radio_tree, hf_wlan_radio_frequency, tvb, 0, 0, phdr->frequency);
+  }
 
-    if (phdr->has_signal_percent) {
-      col_add_fstr(pinfo->cinfo, COL_RSSI, "%u%%", phdr->signal_percent);
-      proto_tree_add_uint(radio_tree, hf_wlan_radio_signal_percent, tvb, 0, 0, phdr->signal_percent);
-    }
+  if (phdr->has_signal_percent) {
+    col_add_fstr(pinfo->cinfo, COL_RSSI, "%u%%", phdr->signal_percent);
+    proto_tree_add_uint(radio_tree, hf_wlan_radio_signal_percent, tvb, 0, 0, phdr->signal_percent);
+  }
 
-    if (phdr->has_signal_dbm) {
-      col_add_fstr(pinfo->cinfo, COL_RSSI, "%d dBm", phdr->signal_dbm);
-      proto_tree_add_int(radio_tree, hf_wlan_radio_signal_dbm, tvb, 0, 0, phdr->signal_dbm);
-    }
+  if (phdr->has_signal_dbm) {
+    col_add_fstr(pinfo->cinfo, COL_RSSI, "%d dBm", phdr->signal_dbm);
+    proto_tree_add_int(radio_tree, hf_wlan_radio_signal_dbm, tvb, 0, 0, phdr->signal_dbm);
+  }
 
-    if (phdr->has_noise_percent) {
-      proto_tree_add_uint(radio_tree, hf_wlan_radio_noise_percent, tvb, 0, 0, phdr->noise_percent);
-    }
+  if (phdr->has_noise_percent) {
+    proto_tree_add_uint(radio_tree, hf_wlan_radio_noise_percent, tvb, 0, 0, phdr->noise_percent);
+  }
 
-    if (phdr->has_noise_dbm) {
-      proto_tree_add_int(radio_tree, hf_wlan_radio_noise_dbm, tvb, 0, 0, phdr->noise_dbm);
-    }
+  if (phdr->has_noise_dbm) {
+    proto_tree_add_int(radio_tree, hf_wlan_radio_noise_dbm, tvb, 0, 0, phdr->noise_dbm);
+  }
 
-    if (phdr->has_tsf_timestamp) {
-      proto_tree_add_uint64(radio_tree, hf_wlan_radio_timestamp, tvb, 0, 0,
-              phdr->tsf_timestamp);
-    }
-    if (phdr->has_aggregate_info) {
-      proto_tree_add_boolean(radio_tree, hf_wlan_last_part_of_a_mpdu, tvb, 0, 0,
-              (phdr->aggregate_flags & PHDR_802_11_LAST_PART_OF_A_MPDU) ?
-               TRUE : FALSE);
-      proto_tree_add_boolean(radio_tree, hf_wlan_a_mpdu_delim_crc_error, tvb, 0, 0,
-              (phdr->aggregate_flags & PHDR_802_11_A_MPDU_DELIM_CRC_ERROR) ?
-               TRUE : FALSE);
-      proto_tree_add_uint(radio_tree, hf_wlan_a_mpdu_aggregate_id, tvb, 0, 0,
-              phdr->aggregate_id);
+  if (phdr->has_tsf_timestamp) {
+    proto_tree_add_uint64(radio_tree, hf_wlan_radio_timestamp, tvb, 0, 0, phdr->tsf_timestamp);
+  }
+  if (phdr->has_aggregate_info) {
+    proto_tree_add_boolean(radio_tree, hf_wlan_last_part_of_a_mpdu, tvb, 0, 0, phdr->aggregate_flags);
+    proto_tree_add_boolean(radio_tree, hf_wlan_a_mpdu_delim_crc_error, tvb, 0, 0, phdr->aggregate_flags);
+    proto_tree_add_uint(radio_tree, hf_wlan_a_mpdu_aggregate_id, tvb, 0, 0, phdr->aggregate_id);
+  }
+
+  if (have_data_rate) {
+    /* duration calculations */
+    gboolean assumed_short_preamble = FALSE;
+    gboolean assumed_non_greenfield = FALSE;
+    gboolean assumed_no_stbc = FALSE;
+    gboolean assumed_no_extension_streams = FALSE;
+    gboolean assumed_bcc_fec = FALSE;
+
+    /* some generators report CCK frames as 'dynamic-cck-ofdm', which are converted
+     * into the 11g PHY type, so we need to be smart and recognize which ones are
+     * DSSS/CCK and which are OFDM. Use the data_rate to do this. */
+    if (phy == PHDR_802_11_PHY_11G &&
+      (data_rate == 1.0f || data_rate == 2.0f ||
+      data_rate == 5.5f || data_rate == 11.0f ||
+      data_rate == 22.0f || data_rate == 33.0f)) {
+      phy = PHDR_802_11_PHY_11B;
     }
 
-    if (have_data_rate) {
-      gboolean assumed_short_preamble = FALSE;
-      gboolean assumed_non_greenfield = FALSE;
-      gboolean assumed_no_stbc = FALSE;
-      gboolean assumed_no_extension_streams = FALSE;
-      gboolean assumed_bcc_fec = FALSE;
-
-        /* some generators report CCK frames as 'dynamic-cck-ofdm', which are converted
-         * into the 11g PHY type, so we need to be smart and recognize which ones are
-         * DSSS/CCK and which are OFDM. Use the data_rate to do this. */
-        int phy = phdr->phy;
-        if (phy == PHDR_802_11_PHY_11G &&
-          (data_rate == 1.0f || data_rate == 2.0f ||
-          data_rate == 5.5f || data_rate == 11.0f ||
-          data_rate == 22.0f || data_rate == 33.0f)) {
-          phy = PHDR_802_11_PHY_11B;
-        }
+    switch (phy) {
 
-        switch (phy) {
+    case PHDR_802_11_PHY_11_FHSS:
+      /* TODO: preamble/duration calc for FHSS */
+      break;
 
-        case PHDR_802_11_PHY_11_FHSS:
-          break;
-
-        case PHDR_802_11_PHY_11B:
-          if (!has_short_preamble || wlan_radio_always_short_preamble) {
-              assumed_short_preamble = TRUE;
-              short_preamble = TRUE;
-          }
-          preamble = short_preamble ? 72 + 24 : 144 + 48;
+    case PHDR_802_11_PHY_11B:
+      if (!has_short_preamble || wlan_radio_always_short_preamble) {
+          assumed_short_preamble = TRUE;
+          short_preamble = TRUE;
+      }
+      preamble = short_preamble ? 72 + 24 : 144 + 48;
+
+      /* calculation of frame duration
+       * Things we need to know to calculate accurate duration
+       * 802.11 / 802.11b (DSSS or CCK modulation)
+       * - length of preamble
+       * - rate
+       */
+      /* round up to whole microseconds */
+      duration = (guint) ceil(preamble + frame_length * 8 / data_rate);
+      break;
+
+    case PHDR_802_11_PHY_11A:
+    case PHDR_802_11_PHY_11G:
+    {
+        /* OFDM rate */
+      /* calculation of frame duration
+       * Things we need to know to calculate accurate duration
+       * 802.11a / 802.11g (OFDM modulation)
+       * - rate
+       */
+
+      /* preamble + signal */
+      preamble = 16 + 4;
+
+      /* 16 service bits, data and 6 tail bits */
+      guint bits = 16 + 8 * frame_length + 6;
+      guint symbols = (guint) ceil(bits / (data_rate * 4));
+
+      duration = preamble + symbols * 4;
+      break;
+    }
 
-          /* calculation of frame duration
-           * Things we need to know to calculate accurate duration
-           * 802.11 / 802.11b (DSSS or CCK modulation)
-           * - length of preamble
-           * - rate
-           */
-          /* round up to whole microseconds */
-          duration = (guint) ceil(preamble + frame_length * 8 / data_rate);
+    case PHDR_802_11_PHY_11N:
+    {
+      struct ieee_802_11n *info_n = &phdr->phy_info.info_11n;
+
+      /* We have all the fields required to calculate the duration */
+      static const guint Nhtdltf[4] = {1, 2, 4, 4};
+      static const guint Nhteltf[4] = {0, 1, 2, 4};
+      guint Nsts;
+      guint stbc_streams;
+      guint ness;
+
+      /*
+       * If we don't have necessary fields, or if we have them but
+       * they have invalid values, then bail.
+       */
+      if (!info_n->has_mcs_index ||
+        info_n->mcs_index > MAX_MCS_INDEX ||
+        !info_n->has_bandwidth ||
+        !info_n->has_short_gi)
           break;
 
-        case PHDR_802_11_PHY_11A:
-        case PHDR_802_11_PHY_11G:
-        {
-          /* OFDM rate */
-          /* calculation of frame duration
-           * Things we need to know to calculate accurate duration
-           * 802.11a / 802.11g (OFDM modulation)
-           * - rate
-           */
-
-          /* 16 service bits, data and 6 tail bits */
-          guint bits = 16 + 8 * frame_length + 6;
-          guint symbols = (guint) ceil(bits / (data_rate * 4));
+      /* calculation of frame duration
+       * Things we need to know to calculate accurate duration
+       * 802.11n / HT
+       * - whether frame preamble is mixed or greenfield, (assume mixed)
+       * - guard interval, 800ns or 400ns
+       * - bandwidth, 20Mhz or 40Mhz
+       * - MCS index - used with previous 2 to calculate rate
+       * - how many additional STBC streams are used (assume 0)
+       * - how many optional extension spatial streams are used (assume 0)
+       * - whether BCC or LDCP coding is used (assume BCC)
+       */
+
+      /* preamble duration
+       * see ieee802.11n-2009 Figure 20-1 - PPDU format
+       * for HT-mixed format
+       * L-STF 8us, L-LTF 8us, L-SIG 4us, HT-SIG 8us, HT_STF 4us
+       * for HT-greenfield
+       * HT-GF-STF 8us, HT-LTF1 8us, HT_SIG 8us
+       */
+      if (info_n->has_greenfield) {
+        preamble = info_n->greenfield ? 24 : 32;
+      } else {
+        preamble = 32;
+        assumed_non_greenfield = TRUE;
+      }
 
-          /* preamble + signal */
-          preamble = 16 + 4;
+      if (info_n->has_stbc_streams) {
+        stbc_streams = info_n->stbc_streams;
+      } else {
+        stbc_streams = 0;
+        assumed_no_stbc = TRUE;
+      }
 
-          duration = preamble + symbols * 4;
-          break;
+      if (info_n->has_ness) {
+        ness = info_n->ness;
+        if (ness >= G_N_ELEMENTS(Nhteltf)) {
+            /* Not valid */
+            break;
         }
+      } else {
+        ness = 0;
+        assumed_no_extension_streams = TRUE;
+      }
 
-        case PHDR_802_11_PHY_11N:
-        {
-          struct ieee_802_11n *info_n = &phdr->phy_info.info_11n;
-          guint bandwidth_40;
-
-          /* We have all the fields required to calculate the duration */
-          static const guint Nhtdltf[4] = {1, 2, 4, 4};
-          static const guint Nhteltf[4] = {0, 1, 2, 4};
-          guint Nsts, bits, Mstbc, bits_per_symbol, symbols;
-          guint stbc_streams;
-          guint ness;
-
-          /*
-           * If we don't have necessary fields, or if we have them but
-           * they have invalid values, then bail.
-           */
-          if (!info_n->has_mcs_index ||
-            info_n->mcs_index > MAX_MCS_INDEX ||
-            !info_n->has_bandwidth ||
-            !info_n->has_short_gi)
-              break;
-
-          bandwidth_40 = info_n->bandwidth == PHDR_802_11_BANDWIDTH_40_MHZ;
-
-          /* calculation of frame duration
-           * Things we need to know to calculate accurate duration
-           * 802.11n / HT
-           * - whether frame preamble is mixed or greenfield, (assume mixed)
-           * - guard interval, 800ns or 400ns
-           * - bandwidth, 20Mhz or 40Mhz
-           * - MCS index - used with previous 2 to calculate rate
-           * - how many additional STBC streams are used (assume 0)
-           * - how many optional extension spatial streams are used (assume 0)
-           * - whether BCC or LDCP coding is used (assume BCC)
-           */
-
-          /* preamble duration
-           * see ieee802.11n-2009 Figure 20-1 - PPDU format
-           * for HT-mixed format
-           * L-STF 8us, L-LTF 8us, L-SIG 4us, HT-SIG 8us, HT_STF 4us
-           * for HT-greenfield
-           * HT-GF-STF 8us, HT-LTF1 8us, HT_SIG 8us
-           */
-          if (info_n->has_greenfield) {
-            preamble = info_n->greenfield ? 24 : 32;
-          } else {
-            preamble = 32;
-            assumed_non_greenfield = TRUE;
-          }
-
-          if (info_n->has_stbc_streams) {
-            stbc_streams = info_n->stbc_streams;
-          } else {
-            stbc_streams = 0;
-            assumed_no_stbc = TRUE;
-          }
-
-          if (info_n->has_ness) {
-            ness = info_n->ness;
-            if (ness >= G_N_ELEMENTS(Nhteltf)) {
-                /* Not valid */
-                break;
-            }
-          } else {
-            ness = 0;
-            assumed_no_extension_streams = TRUE;
-          }
+      /* calculate number of HT-LTF training symbols.
+       * see ieee80211n-2009 20.3.9.4.6 table 20-11 */
+      Nsts = ieee80211_ht_streams[info_n->mcs_index] + stbc_streams;
+      if (Nsts == 0 || Nsts - 1 >= G_N_ELEMENTS(Nhtdltf)) {
+          /* Not usable */
+          break;
+      }
+      preamble += 4 * (Nhtdltf[Nsts-1] + Nhteltf[ness]);
 
-          /* calculate number of HT-LTF training symbols.
-           * see ieee80211n-2009 20.3.9.4.6 table 20-11 */
-          Nsts = ieee80211_ht_streams[info_n->mcs_index] + stbc_streams;
-          if (Nsts == 0 || Nsts - 1 >= G_N_ELEMENTS(Nhtdltf)) {
-              /* Not usable */
-              break;
-          }
-          preamble += 4 * (Nhtdltf[Nsts-1] + Nhteltf[ness]);
+      if (info_n->has_stbc_streams) {
+        stbc_streams = info_n->stbc_streams;
+      } else {
+        stbc_streams = 0;
+        assumed_no_stbc = TRUE;
+      }
 
-          if (!info_n->has_fec) {
-            assumed_bcc_fec = TRUE;
-          }
+      if (info_n->has_ness) {
+        ness = info_n->ness;
+      } else {
+        ness = 0;
+        assumed_no_extension_streams = TRUE;
+      }
 
-          /* data field calculation */
-          /* see ieee80211n-2009 20.3.11 (20-32) - for BCC FEC */
-          /* TODO: handle LDPC FEC (info_n->fec == 1), it changes the rounding
-           * Currently this is the same logic as BCC */
-          bits = 8 * frame_length + 16 + ieee80211_ht_Nes[info_n->mcs_index] * 6;
-          Mstbc = stbc_streams ? 2 : 1;
-          bits_per_symbol = ieee80211_ht_Dbps[info_n->mcs_index] * (bandwidth_40 ? 2 : 1);
-          symbols = bits / (bits_per_symbol * Mstbc);
-
-          /* round up to whole symbols */
-          if((bits % (bits_per_symbol * Mstbc)) > 0)
-            symbols++;
-
-          symbols *= Mstbc;
-          duration = preamble + (symbols * (info_n->short_gi ? 36 : 40) + 5) / 10;
-          break;
-        }
+      /* calculate number of HT-LTF training symbols.
+       * see ieee80211n-2009 20.3.9.4.6 table 20-11 */
+      Nsts = ieee80211_ht_streams[info_n->mcs_index] + stbc_streams;
+      preamble += 4 * (Nhtdltf[Nsts-1] + Nhteltf[ness]);
 
-        case PHDR_802_11_PHY_11AC:
-        {
-          struct ieee_802_11ac *info_ac = &phdr->phy_info.info_11ac;
-          int bits, stbc;
+      if (!info_n->has_fec) {
+        assumed_bcc_fec = TRUE;
+      }
+      break;
+    }
 
-          /* TODO: this is a crude quick hack, need proper calculation of bits/symbols/FEC/rounding/etc */
-          if (info_ac->has_stbc) {
-            stbc = info_ac->stbc;
-          } else {
-            stbc = 0;
-            assumed_no_stbc = TRUE;
-          }
+    case PHDR_802_11_PHY_11AC:
+    {
+      struct ieee_802_11ac *info_ac = &phy_info->info_11ac;
 
-          preamble = 32 + 4 * info_ac->nss[0] * (stbc+1);
-          bits = 8 * frame_length + 16;
-          duration = (guint) (preamble + bits / data_rate);
-          break;
-        }
+      if (!info_ac->has_stbc) {
+        assumed_no_stbc = TRUE;
       }
+      preamble = 32 + 4 * info_ac->nss[0] * (info_ac->has_stbc ? info_ac->stbc+1 : 1);
+      break;
+    }
+    }
 
     if (duration) {
-        proto_item *item = proto_tree_add_uint(radio_tree, hf_wlan_radio_duration, tvb, 0, 0, duration);
-        PROTO_ITEM_SET_GENERATED(item);
-
-        if (assumed_short_preamble)
-          expert_add_info(pinfo, item, &ei_wlan_radio_assumed_short_preamble);
-        if (assumed_non_greenfield)
-          expert_add_info(pinfo, item, &ei_wlan_radio_assumed_non_greenfield);
-        if (assumed_no_stbc)
-          expert_add_info(pinfo, item, &ei_wlan_radio_assumed_no_stbc);
-        if (assumed_no_extension_streams)
-          expert_add_info(pinfo, item, &ei_wlan_radio_assumed_no_extension_streams);
-        if (assumed_bcc_fec)
-          expert_add_info(pinfo, item, &ei_wlan_radio_assumed_bcc_fec);
-
-        if (preamble) {
-          proto_tree *d_tree = proto_item_add_subtree(item, ett_wlan_radio_duration);
-          proto_item *p_item = proto_tree_add_uint(d_tree, hf_wlan_radio_preamble, tvb, 0, 0, preamble);
-            PROTO_ITEM_SET_GENERATED(p_item);
-        }
+      proto_item *item = proto_tree_add_uint(radio_tree, hf_wlan_radio_duration, tvb, 0, 0, duration);
+      proto_tree *d_tree = proto_item_add_subtree(item, ett_wlan_radio_duration);
+      PROTO_ITEM_SET_GENERATED(item);
+
+      if (assumed_short_preamble)
+        expert_add_info(pinfo, item, &ei_wlan_radio_assumed_short_preamble);
+      if (assumed_non_greenfield)
+        expert_add_info(pinfo, item, &ei_wlan_radio_assumed_non_greenfield);
+      if (assumed_no_stbc)
+        expert_add_info(pinfo, item, &ei_wlan_radio_assumed_no_stbc);
+      if (assumed_no_extension_streams)
+        expert_add_info(pinfo, item, &ei_wlan_radio_assumed_no_extension_streams);
+      if (assumed_bcc_fec)
+        expert_add_info(pinfo, item, &ei_wlan_radio_assumed_bcc_fec);
+
+      if (preamble) {
+        p_item = proto_tree_add_uint(d_tree, hf_wlan_radio_preamble, tvb, 0, 0, preamble);
+        PROTO_ITEM_SET_GENERATED(p_item);
       }
     }
-  } /* if (tree) */
+  } /* if (have_data_rate) */
 }
 
 /*
@@ -950,7 +943,9 @@ dissect_wlan_noqos_radio (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree
   return call_dissector_with_data(ieee80211_noqos_handle, tvb, pinfo, tree, data);
 }
 
-static hf_register_info hf_wlan_radio[] = {
+void proto_register_ieee80211_radio(void)
+{
+  static hf_register_info hf_wlan_radio[] = {
     {&hf_wlan_radio_phy,
      {"PHY type", "wlan_radio.phy", FT_UINT32, BASE_DEC, VALS(phy_vals), 0,
       NULL, HFILL }},
@@ -1100,11 +1095,11 @@ static hf_register_info hf_wlan_radio[] = {
       NULL, HFILL }},
 
     {&hf_wlan_last_part_of_a_mpdu,
-     {"Last part of an A-MPDU", "wlan_radio.last_part_of_an_ampdu", FT_BOOLEAN, 0, NULL, 0,
+     {"Last part of an A-MPDU", "wlan_radio.last_part_of_an_ampdu", FT_BOOLEAN, 32, NULL, PHDR_802_11_LAST_PART_OF_A_MPDU,
       "This is the last part of an A-MPDU", HFILL }},
 
     {&hf_wlan_a_mpdu_delim_crc_error,
-     {"A-MPDU delimiter CRC error", "wlan_radio.a_mpdu_delim_crc_error", FT_BOOLEAN, 0, NULL, 0,
+     {"A-MPDU delimiter CRC error", "wlan_radio.a_mpdu_delim_crc_error", FT_BOOLEAN, 32, NULL, PHDR_802_11_A_MPDU_DELIM_CRC_ERROR,
       NULL, HFILL }},
 
     {&hf_wlan_a_mpdu_aggregate_id,
@@ -1119,10 +1114,15 @@ static hf_register_info hf_wlan_radio[] = {
     {&hf_wlan_radio_preamble,
      {"Preamble", "wlan_radio.preamble", FT_UINT32, BASE_DEC|BASE_UNIT_STRING, &units_microseconds, 0,
       "Duration of the PLCP or preamble in microseconds, calculated from PHY data", HFILL }},
+  };
 
-};
+  static gint *ett[] = {
+    &ett_wlan_radio,
+    &ett_wlan_radio_11ac_user,
+    &ett_wlan_radio_duration,
+  };
 
-static ei_register_info ei[] = {
+  static ei_register_info ei[] = {
     { &ei_wlan_radio_assumed_short_preamble,
       { "wlan_radio.assumed.short_preamble", PI_ASSUMPTION, PI_WARN,
         "No preamble length information was available, assuming short preamble.", EXPFILL }},
@@ -1142,23 +1142,14 @@ static ei_register_info ei[] = {
     { &ei_wlan_radio_assumed_bcc_fec,
       { "wlan_radio.assumed.bcc_fec", PI_ASSUMPTION, PI_WARN,
         "No fec type information was available, assuming bcc fec.", EXPFILL }},
-};
+  };
 
-module_t *wlan_radio_module;
-expert_module_t* expert_wlan_radio;
+  module_t *wlan_radio_module;
+  expert_module_t* expert_wlan_radio;
 
-static gint *tree_array[] = {
-  &ett_wlan_radio,
-  &ett_wlan_radio_11ac_user,
-  &ett_wlan_radio_duration
-};
-
-void proto_register_ieee80211_radio(void)
-{
-  proto_wlan_radio = proto_register_protocol("802.11 radio information", "802.11 Radio",
-                                             "wlan_radio");
+  proto_wlan_radio = proto_register_protocol("802.11 radio information", "802.11 Radio", "wlan_radio");
   proto_register_field_array(proto_wlan_radio, hf_wlan_radio, array_length(hf_wlan_radio));
-  proto_register_subtree_array(tree_array, array_length(tree_array));
+  proto_register_subtree_array(ett, array_length(ett));
 
   expert_wlan_radio = expert_register_protocol(proto_wlan_radio);
   expert_register_field_array(expert_wlan_radio, ei, array_length(ei));
@@ -1172,7 +1163,6 @@ void proto_register_ieee80211_radio(void)
     "Some generators incorrectly indicate long preamble when the preamble was actually"
     "short. Always assume short preamble when calculating duration.",
     &wlan_radio_always_short_preamble);
-
 }
 
 void proto_reg_handoff_ieee80211_radio(void)
diff --git a/wiretap/wtap.h b/wiretap/wtap.h
index c5d9db4c5c..957dc76c6b 100644
--- a/wiretap/wtap.h
+++ b/wiretap/wtap.h
@@ -760,20 +760,22 @@ struct ieee_802_11ad {
     guint8   mcs;            /* MCS index */
 };
 
+union ieee_802_11_phy_info {
+    struct ieee_802_11_fhss info_11_fhss;
+    struct ieee_802_11b info_11b;
+    struct ieee_802_11a info_11a;
+    struct ieee_802_11g info_11g;
+    struct ieee_802_11n info_11n;
+    struct ieee_802_11ac info_11ac;
+    struct ieee_802_11ad info_11ad;
+};
+
 struct ieee_802_11_phdr {
     gint     fcs_len;        /* Number of bytes of FCS - -1 means "unknown" */
     gboolean decrypted;      /* TRUE if frame is decrypted even if "protected" bit is set */
     gboolean datapad;        /* TRUE if frame has padding between 802.11 header and payload */
     guint    phy;            /* PHY type */
-    union {
-        struct ieee_802_11_fhss info_11_fhss;
-        struct ieee_802_11b info_11b;
-        struct ieee_802_11a info_11a;
-        struct ieee_802_11g info_11g;
-        struct ieee_802_11n info_11n;
-        struct ieee_802_11ac info_11ac;
-        struct ieee_802_11ad info_11ad;
-    } phy_info;
+    union ieee_802_11_phy_info phy_info;
 
     /* Which of this information is present? */
     guint    has_channel:1;