"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>

4 files changed, 125 insertions, 66 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:
diff --git a/wiretap/wtap.h b/wiretap/wtap.h
index a8402d8a05..76a3921256 100644
--- a/wiretap/wtap.h
+++ b/wiretap/wtap.h
@@ -571,7 +571,11 @@ struct p2p_phdr {
 /*
  * PHY-specific information.
  */
-struct ieee_802_11_fhss {    /* 802.11 legacy FHSS */
+
+/*
+ * 802.11 legacy FHSS.
+ */
+struct ieee_802_11_fhss {
     guint32  presence_flags; /* Which of this information is present? */
     guint8   hop_set;        /* Hop set */
     guint8   hop_pattern;    /* Hop pattern */
@@ -579,24 +583,43 @@ struct ieee_802_11_fhss {    /* 802.11 legacy FHSS */
 };
 
 /*
- * Presence flags for legacy FHSS.
+ * Presence flags.
  */
 #define PHDR_802_11_FHSS_HAS_HOP_SET      0x0000001
 #define PHDR_802_11_FHSS_HAS_HOP_PATTERN  0x0000002
 #define PHDR_802_11_FHSS_HAS_HOP_INDEX    0x0000004
 
 /*
- * Presence flags for 802.11a.
+ * 802.11b.
  */
-#define PHDR_802_11A_HAS_CHANNEL_TYPE  0x0000001  /* Normal, half-clocked, quarter-clocked */
-#define PHDR_802_11A_HAS_TURBO_TYPE    0x0000002  /* Normal, turbo, "static turbo" */
+struct ieee_802_11b {
+    guint32  presence_flags; /* Which of this information is present? */
+    gboolean short_preamble; /* Short preamble */
+};
 
-struct ieee_802_11a {        /* 802.11a */
+/*
+ * Presence flags.
+ */
+#define PHDR_802_11B_HAS_SHORT_PREAMBLE  0x0000001  /* Short preamble */
+
+/*
+ * 802.11a.
+ */
+struct ieee_802_11a {
     guint32  presence_flags; /* Which of this information is present? */
     guint    channel_type:2;
     guint    turbo_type:2;
 };
 
+/*
+ * Presence flags.
+ */
+#define PHDR_802_11A_HAS_CHANNEL_TYPE  0x0000001  /* Normal, half-clocked, quarter-clocked */
+#define PHDR_802_11A_HAS_TURBO_TYPE    0x0000002  /* Normal, turbo, "static turbo" */
+
+/*
+ * Channel type values.
+ */
 #define PHDR_802_11A_CHANNEL_TYPE_NORMAL           0
 #define PHDR_802_11A_CHANNEL_TYPE_HALF_CLOCKED     1
 #define PHDR_802_11A_CHANNEL_TYPE_QUARTER_CLOCKED  2
@@ -614,20 +637,31 @@ struct ieee_802_11a {        /* 802.11a */
 #define PHDR_802_11A_TURBO_TYPE_DYNAMIC_TURBO    2
 #define PHDR_802_11A_TURBO_TYPE_STATIC_TURBO     3
 
-struct ieee_802_11g {        /* 802.11g */
+/*
+ * 802.11g.
+ */
+struct ieee_802_11g {
     guint32  presence_flags; /* Which of this information is present? */
+    gboolean short_preamble; /* Short preamble */
     guint32  mode;           /* Various proprietary extensions */
 };
 
 /*
- * Presence flags for 802.11g.
+ * Presence flags.
  */
-#define PHDR_802_11G_HAS_MODE  0x0000001  /* Proprietary extensions */
+#define PHDR_802_11G_HAS_SHORT_PREAMBLE  0x0000001  /* Short preamble */
+#define PHDR_802_11G_HAS_MODE            0x0000002  /* Proprietary extensions */
 
+/*
+ * Mode values.
+ */
 #define PHDR_802_11G_MODE_NORMAL    0
 #define PHDR_802_11G_MODE_SUPER_G   1  /* Atheros Super G */
 
-struct ieee_802_11n {        /* 802.11n */
+/*
+ * 802.11n.
+ */
+struct ieee_802_11n {
     guint32  presence_flags; /* Which of this information is present? */
     guint16  mcs_index;      /* MCS index */
     guint    bandwidth;      /* Bandwidth = 20 MHz, 40 MHz, etc. */
@@ -639,7 +673,7 @@ struct ieee_802_11n {        /* 802.11n */
 };
 
 /*
- * Presence flags for 802.11n.
+ * Presence flags.
  */
 #define PHDR_802_11N_HAS_MCS_INDEX      0x00000001 /* mcs */
 #define PHDR_802_11N_HAS_BANDWIDTH      0x00000002 /* bandwidth */
@@ -649,7 +683,9 @@ struct ieee_802_11n {        /* 802.11n */
 #define PHDR_802_11N_HAS_STBC_STREAMS   0x00000020 /* stbc_streams */
 #define PHDR_802_11N_HAS_NESS           0x00000040 /* ness */
 
-/* Used for both 11n and 11ac */
+/*
+ * Bandwidth values; used for both 11n and 11ac.
+ */
 #define PHDR_802_11_BANDWIDTH_20_MHZ   0  /* 20 MHz */
 #define PHDR_802_11_BANDWIDTH_40_MHZ   1  /* 40 MHz */
 #define PHDR_802_11_BANDWIDTH_20_20L   2  /* 20 + 20L, 40 MHz */
@@ -677,7 +713,10 @@ struct ieee_802_11n {        /* 802.11n */
 #define PHDR_802_11_BANDWIDTH_20UUL    24 /* ???, 160 MHz */
 #define PHDR_802_11_BANDWIDTH_20UUU    25 /* ???, 160 MHz */
 
-struct ieee_802_11ac {       /* 802.11ac */
+/*
+ * 802.11ac.
+ */
+struct ieee_802_11ac {
     guint32  presence_flags; /* Which of this information is present? */
     guint    stbc:1;         /* 1 if all spatial streams have STBC */
     guint    txop_ps_not_allowed:1;
@@ -694,7 +733,7 @@ struct ieee_802_11ac {       /* 802.11ac */
 };
 
 /*
- * Presence flags for 802.11ac.
+ * Presence flags.
  */
 #define PHDR_802_11AC_HAS_STBC                    0x00000001 /* stbc */
 #define PHDR_802_11AC_HAS_TXOP_PS_NOT_ALLOWED     0x00000002 /* txop_ps_not_allowed */
@@ -713,6 +752,7 @@ struct ieee_802_11_phdr {
     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;
@@ -721,7 +761,6 @@ struct ieee_802_11_phdr {
     guint32  presence_flags; /* Flags indicating presence of fields below */
     guint16  channel;        /* Channel number */
     guint32  frequency;      /* Channel center frequency */
-    gboolean short_preamble; /* Short preamble */
     guint16  data_rate;      /* Data rate, in .5 Mb/s units */
     guint8   signal_percent; /* Signal level, as a percentage */
     guint8   noise_percent;  /* Noise level, as a percentage */
@@ -735,13 +774,12 @@ struct ieee_802_11_phdr {
  */
 #define PHDR_802_11_HAS_CHANNEL         0x00000001 /* channel */
 #define PHDR_802_11_HAS_FREQUENCY       0x00000002 /* frequency */
-#define PHDR_802_11_HAS_SHORT_PREAMBLE  0x00000004 /* short_preamble */
-#define PHDR_802_11_HAS_DATA_RATE       0x00000008 /* data_rate */
-#define PHDR_802_11_HAS_SIGNAL_PERCENT  0x00000010 /* signal_percent */
-#define PHDR_802_11_HAS_NOISE_PERCENT   0x00000020 /* noise_percent */
-#define PHDR_802_11_HAS_SIGNAL_DBM      0x00000040 /* signal_dbm */
-#define PHDR_802_11_HAS_NOISE_DBM       0x00000080 /* noise_dbm */
-#define PHDR_802_11_HAS_TSF_TIMESTAMP   0x00000100 /* tsf_timestamp */
+#define PHDR_802_11_HAS_DATA_RATE       0x00000004 /* data_rate */
+#define PHDR_802_11_HAS_SIGNAL_PERCENT  0x00000008 /* signal_percent */
+#define PHDR_802_11_HAS_NOISE_PERCENT   0x00000010 /* noise_percent */
+#define PHDR_802_11_HAS_SIGNAL_DBM      0x00000020 /* signal_dbm */
+#define PHDR_802_11_HAS_NOISE_DBM       0x00000040 /* noise_dbm */
+#define PHDR_802_11_HAS_TSF_TIMESTAMP   0x00000080 /* tsf_timestamp */
 
 /* Packet "pseudo-header" for the output from CoSine L2 debug output. */