"Short preamble" is 802.11[bg]-only, so put it in the PHY-specifc info.

We're already only setting it for 11b and 11g; this makes it a bit
cleaner, e.g. we don't need to say "oh, wait, we *don't* have short
preamble" for 11n and 11ac.

Change-Id: Idcf3e8c93d6a417f0319e4bd33247b98f07b6052
Reviewed-on: https://code.wireshark.org/review/9209
Reviewed-by: Guy Harris <guy@alum.mit.edu>

3 files changed, 65 insertions, 44 deletions

diff --git a/epan/dissectors/packet-ieee80211-radio.c b/epan/dissectors/packet-ieee80211-radio.c
index 94ba5d69f7..0b9f404abf 100644
--- a/epan/dissectors/packet-ieee80211-radio.c
+++ b/epan/dissectors/packet-ieee80211-radio.c
@@ -704,6 +704,13 @@ dissect_wlan_radio (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void
         }
         break;
 
+      case PHDR_802_11_PHY_11B:
+        if (phdr->phy_info.info_11b.presence_flags & PHDR_802_11B_HAS_SHORT_PREAMBLE) {
+          proto_tree_add_boolean(radio_tree, hf_wlan_radio_short_preamble, tvb, 0, 0,
+                   phdr->phy_info.info_11b.short_preamble);
+        }
+        break;
+
       case PHDR_802_11_PHY_11A:
         if (phdr->phy_info.info_11a.presence_flags & PHDR_802_11A_HAS_CHANNEL_TYPE) {
           proto_tree_add_uint(radio_tree, hf_wlan_radio_11a_channel_type, tvb, 0, 0,
@@ -716,6 +723,10 @@ dissect_wlan_radio (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void
         break;
 
       case PHDR_802_11_PHY_11G:
+        if (phdr->phy_info.info_11g.presence_flags & PHDR_802_11G_HAS_SHORT_PREAMBLE) {
+          proto_tree_add_boolean(radio_tree, hf_wlan_radio_short_preamble, tvb, 0, 0,
+                   phdr->phy_info.info_11g.short_preamble);
+        }
         if (phdr->phy_info.info_11g.presence_flags & PHDR_802_11G_HAS_MODE) {
           proto_tree_add_uint(radio_tree, hf_wlan_radio_11g_mode, tvb, 0, 0,
                    phdr->phy_info.info_11g.mode);
@@ -922,11 +933,6 @@ dissect_wlan_radio (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void
               phdr->frequency);
     }
 
-    if (phdr->presence_flags & PHDR_802_11_HAS_SHORT_PREAMBLE) {
-      proto_tree_add_boolean(radio_tree, hf_wlan_radio_short_preamble, tvb, 0, 0,
-               phdr->short_preamble);
-    }
-
     if (phdr->presence_flags & PHDR_802_11_HAS_SIGNAL_PERCENT) {
       col_add_fstr(pinfo->cinfo, COL_RSSI, "%u%%", phdr->signal_percent);
       proto_tree_add_uint_format_value(radio_tree, hf_wlan_radio_signal_percent, tvb, 0, 0,
diff --git a/epan/dissectors/packet-ieee80211-radiotap.c b/epan/dissectors/packet-ieee80211-radiotap.c
index 58452aae13..0629cab41d 100644
--- a/epan/dissectors/packet-ieee80211-radiotap.c
+++ b/epan/dissectors/packet-ieee80211-radiotap.c
@@ -963,30 +963,31 @@ dissect_radiotap(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
 
 			case IEEE80211_CHAN_B:
 				phdr.phy = PHDR_802_11_PHY_11B;
+				phdr.phy_info.info_11b.presence_flags = 0;
 				if (have_rflags) {
-					phdr.presence_flags |= PHDR_802_11_HAS_SHORT_PREAMBLE;
-					phdr.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
+					phdr.phy_info.info_11b.presence_flags |= PHDR_802_11B_HAS_SHORT_PREAMBLE;
+					phdr.phy_info.info_11b.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
 				}
 				break;
 
 			case IEEE80211_CHAN_PUREG:
 				phdr.phy = PHDR_802_11_PHY_11G;
-				if (have_rflags) {
-					phdr.presence_flags |= PHDR_802_11_HAS_SHORT_PREAMBLE;
-					phdr.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
-				}
 				phdr.phy_info.info_11g.presence_flags = PHDR_802_11G_HAS_MODE;
 				phdr.phy_info.info_11g.mode = PHDR_802_11G_MODE_NORMAL;
+				if (have_rflags) {
+					phdr.phy_info.info_11g.presence_flags |= PHDR_802_11G_HAS_SHORT_PREAMBLE;
+					phdr.phy_info.info_11g.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
+				}
 				break;
 
 			case IEEE80211_CHAN_G:
 				phdr.phy = PHDR_802_11_PHY_11G;
-				if (have_rflags) {
-					phdr.presence_flags |= PHDR_802_11_HAS_SHORT_PREAMBLE;
-					phdr.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
-				}
 				phdr.phy_info.info_11g.presence_flags = PHDR_802_11G_HAS_MODE;
 				phdr.phy_info.info_11g.mode = PHDR_802_11G_MODE_NORMAL;
+				if (have_rflags) {
+					phdr.phy_info.info_11g.presence_flags |= PHDR_802_11G_HAS_SHORT_PREAMBLE;
+					phdr.phy_info.info_11g.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
+				}
 				break;
 
 			case IEEE80211_CHAN_108A:
@@ -998,12 +999,12 @@ dissect_radiotap(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
 
 			case IEEE80211_CHAN_108PUREG:
 				phdr.phy = PHDR_802_11_PHY_11G;
-				if (have_rflags) {
-					phdr.presence_flags |= PHDR_802_11_HAS_SHORT_PREAMBLE;
-					phdr.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
-				}
 				phdr.phy_info.info_11g.presence_flags = PHDR_802_11G_HAS_MODE;
 				phdr.phy_info.info_11g.mode = PHDR_802_11G_MODE_SUPER_G;
+				if (have_rflags) {
+					phdr.phy_info.info_11g.presence_flags |= PHDR_802_11G_HAS_SHORT_PREAMBLE;
+					phdr.phy_info.info_11g.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
+				}
 				break;
 			}
 			if (tree) {
@@ -1200,30 +1201,31 @@ dissect_radiotap(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
 
 			case IEEE80211_CHAN_B:
 				phdr.phy = PHDR_802_11_PHY_11B;
+				phdr.phy_info.info_11b.presence_flags = 0;
 				if (have_rflags) {
-					phdr.presence_flags |= PHDR_802_11_HAS_SHORT_PREAMBLE;
-					phdr.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
+					phdr.phy_info.info_11b.presence_flags |= PHDR_802_11B_HAS_SHORT_PREAMBLE;
+					phdr.phy_info.info_11b.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
 				}
 				break;
 
 			case IEEE80211_CHAN_PUREG:
 				phdr.phy = PHDR_802_11_PHY_11G;
-				if (have_rflags) {
-					phdr.presence_flags |= PHDR_802_11_HAS_SHORT_PREAMBLE;
-					phdr.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
-				}
 				phdr.phy_info.info_11g.presence_flags = PHDR_802_11G_HAS_MODE;
 				phdr.phy_info.info_11g.mode = PHDR_802_11G_MODE_NORMAL;
+				if (have_rflags) {
+					phdr.phy_info.info_11g.presence_flags |= PHDR_802_11G_HAS_SHORT_PREAMBLE;
+					phdr.phy_info.info_11g.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
+				}
 				break;
 
 			case IEEE80211_CHAN_G:
 				phdr.phy = PHDR_802_11_PHY_11G;
-				if (have_rflags) {
-					phdr.presence_flags |= PHDR_802_11_HAS_SHORT_PREAMBLE;
-					phdr.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
-				}
 				phdr.phy_info.info_11g.presence_flags = PHDR_802_11G_HAS_MODE;
 				phdr.phy_info.info_11g.mode = PHDR_802_11G_MODE_NORMAL;
+				if (have_rflags) {
+					phdr.phy_info.info_11g.presence_flags |= PHDR_802_11G_HAS_SHORT_PREAMBLE;
+					phdr.phy_info.info_11g.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
+				}
 				break;
 
 			case IEEE80211_CHAN_108A:
@@ -1235,12 +1237,12 @@ dissect_radiotap(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
 
 			case IEEE80211_CHAN_108PUREG:
 				phdr.phy = PHDR_802_11_PHY_11G;
-				if (have_rflags) {
-					phdr.presence_flags |= PHDR_802_11_HAS_SHORT_PREAMBLE;
-					phdr.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
-				}
 				phdr.phy_info.info_11g.presence_flags = PHDR_802_11G_HAS_MODE;
 				phdr.phy_info.info_11g.mode = PHDR_802_11G_MODE_SUPER_G;
+				if (have_rflags) {
+					phdr.phy_info.info_11g.presence_flags |= PHDR_802_11G_HAS_SHORT_PREAMBLE;
+					phdr.phy_info.info_11g.short_preamble = (rflags & IEEE80211_RADIOTAP_F_SHORTPRE) != 0;
+				}
 				break;
 
 			case IEEE80211_CHAN_ST:
@@ -1256,8 +1258,6 @@ dissect_radiotap(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
 			case IEEE80211_CHAN_G|IEEE80211_CHAN_HT40U:
 			case IEEE80211_CHAN_G|IEEE80211_CHAN_HT40D:
 				phdr.phy = PHDR_802_11_PHY_11N;
-				/* 11n only has "short preamble" in 11b/11g mode */
-				phdr.presence_flags &= ~PHDR_802_11_HAS_SHORT_PREAMBLE;
 				phdr.phy_info.info_11n.presence_flags = 0;
 
 				/*
@@ -1348,8 +1348,6 @@ dissect_radiotap(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
 			 */
 			if (mcs_known != 0) {
 				phdr.phy = PHDR_802_11_PHY_11N;
-				/* 11n only has "short preamble" in 11b/11g mode */
-				phdr.presence_flags &= ~PHDR_802_11_HAS_SHORT_PREAMBLE;
 				phdr.phy_info.info_11n.presence_flags = 0;
 			}
 
@@ -1548,7 +1546,6 @@ dissect_radiotap(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
 			 */
 			if (known != 0) {
 				phdr.phy = PHDR_802_11_PHY_11AC;
-				phdr.presence_flags &= ~PHDR_802_11_HAS_SHORT_PREAMBLE;
 				phdr.phy_info.info_11ac.presence_flags = 0;
 			}
 			vht_flags = tvb_get_guint8(tvb, offset + 2);
diff --git a/epan/dissectors/packet-ieee80211-wlancap.c b/epan/dissectors/packet-ieee80211-wlancap.c
index 3004c0fdac..fc348b46f3 100644
--- a/epan/dissectors/packet-ieee80211-wlancap.c
+++ b/epan/dissectors/packet-ieee80211-wlancap.c
@@ -614,11 +614,19 @@ dissect_wlancap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     case 1:
       /*
        * Short preamble.
-       * We assume this is present only for PHYs that support variable
-       * preamble lengths.
        */
-      phdr.presence_flags |= PHDR_802_11_HAS_SHORT_PREAMBLE;
-      phdr.short_preamble = TRUE;
+      switch (phdr.phy) {
+
+      case PHDR_802_11_PHY_11B:
+        phdr.phy_info.info_11b.presence_flags |= PHDR_802_11B_HAS_SHORT_PREAMBLE;
+        phdr.phy_info.info_11b.short_preamble = TRUE;
+        break;
+
+      case PHDR_802_11_PHY_11G:
+        phdr.phy_info.info_11g.presence_flags |= PHDR_802_11G_HAS_SHORT_PREAMBLE;
+        phdr.phy_info.info_11g.short_preamble = TRUE;
+        break;
+      }
       break;
 
     case 2:
@@ -627,8 +635,18 @@ dissect_wlancap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
        * We assume this is present only for PHYs that support variable
        * preamble lengths.
        */
-      phdr.presence_flags |= PHDR_802_11_HAS_SHORT_PREAMBLE;
-      phdr.short_preamble = FALSE;
+      switch (phdr.phy) {
+
+      case PHDR_802_11_PHY_11B:
+        phdr.phy_info.info_11b.presence_flags |= PHDR_802_11B_HAS_SHORT_PREAMBLE;
+        phdr.phy_info.info_11b.short_preamble = FALSE;
+        break;
+
+      case PHDR_802_11_PHY_11G:
+        phdr.phy_info.info_11g.presence_flags |= PHDR_802_11G_HAS_SHORT_PREAMBLE;
+        phdr.phy_info.info_11g.short_preamble = FALSE;
+        break;
+      }
       break;
 
     default: