Clean up fixed field handling

- Get rid of FF_FIELD macro. Use resoved strings instead.
- Reorder add_ff_ functions so we don't need forward declarations
- Replace add_fixed_field call by call to resolved function
- Remove add_fixed_field and all structs and enums exclusive to it.
- #if 0 out unused function add_ff_relay_capable_sta_info

Change-Id: I9955febb317f3e7c1b9ae28a5ee9c6a6472f7e9c
Reviewed-on: https://code.wireshark.org/review/16328
Reviewed-by: Jörg Mayer <jmayer@loplof.de>

1 files changed, 555 insertions, 828 deletions

diff --git a/epan/dissectors/packet-ieee80211.c b/epan/dissectors/packet-ieee80211.c
index 37cb8f79b9..c6255acff3 100644
--- a/epan/dissectors/packet-ieee80211.c
+++ b/epan/dissectors/packet-ieee80211.c
@@ -341,132 +341,6 @@ typedef struct mimo_control
 #define DATA_LONG_HDR_LEN      30
 #define MGT_FRAME_HDR_LEN      24  /* Length of Management frame-headers */
 
-
-/* ************************************************************************* */
-/*        Logical field codes (dissector's encoding of fixed fields)         */
-/* ************************************************************************* */
-enum fixed_field {
-  FIELD_TIMESTAMP,                            /* 64-bit timestamp */
-  FIELD_BEACON_INTERVAL,                      /* 16-bit beacon interval */
-  FIELD_CAP_INFO,                             /* Add capability information tree */
-  FIELD_AUTH_ALG,                             /* Authentication algorithm used */
-  FIELD_AUTH_TRANS_SEQ,                       /* Authentication sequence number */
-  FIELD_CURRENT_AP_ADDR,
-  FIELD_LISTEN_IVAL,
-  FIELD_REASON_CODE,
-  FIELD_ASSOC_ID,
-  FIELD_STATUS_CODE,
-  FIELD_CATEGORY_CODE,                        /* Management action category */
-  FIELD_ACTION_CODE,                          /* Management action code */
-  FIELD_DIALOG_TOKEN,                         /* Management action dialog token */
-  FIELD_FOLLOWUP_DIALOG_TOKEN,
-  FIELD_WME_ACTION_CODE,                      /* Management notification action code */
-  FIELD_WME_DIALOG_TOKEN,                     /* Management notification dialog token */
-  FIELD_WME_STATUS_CODE,                      /* Management notification setup response status code */
-  FIELD_QOS_ACTION_CODE,
-  FIELD_QOS_TS_INFO,
-  FIELD_DLS_ACTION_CODE,
-  FIELD_DST_MAC_ADDR,                         /* DLS destination MAC address */
-  FIELD_SRC_MAC_ADDR,                         /* DLS source MAC address */
-  FIELD_DLS_TIMEOUT,                          /* DLS timeout value */
-  FIELD_SCHEDULE_INFO,                        /* Schedule Info field */
-  FIELD_ACTION,                               /* Action field */
-  FIELD_BLOCK_ACK_ACTION_CODE,
-  FIELD_QOS_INFO_AP,
-  FIELD_QOS_INFO_STA,
-  FIELD_BLOCK_ACK_PARAM,
-  FIELD_BLOCK_ACK_TIMEOUT,
-  FIELD_BLOCK_ACK_SSC,
-  FIELD_DELBA_PARAM_SET,
-  FIELD_MAX_REG_PWR,
-  FIELD_MEASUREMENT_PILOT_INT,
-  FIELD_COUNTRY_STR,
-  FIELD_MAX_TX_PWR,
-  FIELD_TX_PWR_USED,
-  FIELD_TRANSCEIVER_NOISE_FLOOR,
-  FIELD_DS_PARAM_SET,
-  FIELD_CHANNEL_WIDTH,
-  FIELD_SM_PWR_CNTRL,
-  FIELD_PCO_PHASE_CNTRL,
-  FIELD_PSMP_PARAM_SET,
-  FIELD_PSMP_STA_INFO,
-  FIELD_MIMO_CNTRL,
-  FIELD_ANT_SELECTION,
-  FIELD_EXTENDED_CHANNEL_SWITCH_ANNOUNCEMENT,
-  FIELD_HT_INFORMATION,
-  FIELD_HT_ACTION_CODE,
-  FIELD_PA_ACTION_CODE,
-  FIELD_PPA_ACTION_CODE,
-  FIELD_FT_ACTION_CODE,
-  FIELD_STA_ADDRESS,
-  FIELD_TARGET_AP_ADDRESS,
-  FIELD_GAS_COMEBACK_DELAY,
-  FIELD_GAS_FRAGMENT_ID,
-  FIELD_SA_QUERY_ACTION_CODE,
-  FIELD_TRANSACTION_ID,
-  FIELD_TDLS_ACTION_CODE,
-  FIELD_TARGET_CHANNEL,
-  FIELD_OPERATING_CLASS,
-  FIELD_MESH_ACTION,
-  FIELD_MULTIHOP_ACTION,
-  FIELD_MESH_CONTROL,
-  FIELD_SELFPROT_ACTION,
-  FIELD_WNM_ACTION_CODE,
-  FIELD_UNPROTECTED_WNM_ACTION_CODE,
-  FIELD_RELAY_CAPABLE_STA_INFO,
-  FIELD_BAND_ID,
-  FIELD_DMG_PARAMETERS,
-  FIELD_SECTOR_SWEEP,
-  FIELD_DYNAMIC_ALLOCATION,
-  FIELD_SECTOR_SWEEP_FB,
-  FIELD_BRP_REQ,
-  FIELD_BEAMFORMING_CTRL,
-  FIELD_BEAMFORMED_LINK_MAINTAINCE,
-  FIELD_BEACON_INTERVAL_CTRL,
-  FIELD_KEY_DATA_LENGTH,
-  FIELD_WNM_NOTIFICATION_TYPE,
-  FIELD_RM_ACTION_CODE,
-  FIELD_RM_DIALOG_TOKEN,
-  FIELD_RM_REPETITIONS,
-  FIELD_RM_TX_POWER,
-  FIELD_RM_MAX_TX_POWER,
-  FIELD_RM_TPC_REPORT,
-  FIELD_RM_RX_ANTENNA_ID,
-  FIELD_RM_TX_ANTENNA_ID,
-  FIELD_RM_RCPI,
-  FIELD_RM_RSNI,
-  FIELD_DMG_ACTION_CODE,
-  FIELD_DMG_PWR_MGMT,
-  FIELD_REQ_AP_ADDR,
-  FIELD_RES_AP_ADDR,
-  FIELD_CHECK_BEACON,
-  FIELD_TOD,
-  FIELD_TOA,
-  FIELD_MAX_TOD_ERR,
-  FIELD_MAX_TOA_ERR,
-  FIELD_SUBJECT_ADDRESS,
-  FIELD_HANDOVER_REASON,
-  FIELD_HANDOVER_REMAINING_BI,
-  FIELD_HANDOVER_RESULT,
-  FIELD_HANDOVER_REJECT_REASON,
-  FIELD_DESTINATION_REDS_AID,
-  FIELD_DESTINATION_AID,
-  FIELD_REALY_AID,
-  FIELD_SOURCE_AID,
-  FIELD_TIMING_OFFSET,
-  FIELD_SAMPLING_FREQUENCY_OFFSET,
-  FIELD_RELAY_OPERATION_TYPE,
-  FIELD_UNPROTECTED_DMG_ACTION_CODE,
-  FIELD_FST_ACTION_CODE,
-  FIELD_LLT,
-  FIELD_FSTS_ID,
-  FIELD_OCT_MMPDU,
-  FIELD_VHT_ACTION,
-  FIELD_BSS_TERMINATION_DELAY,
-  FIELD_BSS_TRANSITION_STATUS_CODE,
-  MAX_FIELD_NUM /* add any new fixed field value above this line */
-};
-
 /* ************************************************************************* */
 /*        Logical field codes (IEEE 802.11 encoding of tags)                 */
 /* ************************************************************************* */
@@ -6906,10 +6780,6 @@ dissect_gas_comeback_response(proto_tree *tree, tvbuff_t *tvb, packet_info *pinf
 /*              Dissect and add fixed mgmt fields to protocol tree           */
 /* ************************************************************************* */
 
-static guint
-add_fixed_field(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset,
-                enum fixed_field lfcode);
-
 static guint64 last_timestamp;
 
 static guint
@@ -7598,6 +7468,248 @@ add_ff_ppa_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_,
 }
 
 static guint
+add_ff_ft_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_ft_action_code, tvb, offset, 1,
+                      ENC_LITTLE_ENDIAN);
+  return 1;
+}
+
+static guint
+add_ff_sta_address(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_sta_address, tvb, offset, 6,
+                      ENC_NA);
+  return 6;
+}
+
+static guint
+add_ff_target_ap_address(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_target_ap_address, tvb, offset, 6,
+                      ENC_NA);
+  return 6;
+}
+
+static guint
+add_ff_gas_comeback_delay(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_gas_comeback_delay, tvb, offset, 2,
+                      ENC_LITTLE_ENDIAN);
+  return 2;
+}
+
+static guint
+add_ff_gas_fragment_id(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_gas_fragment_id, tvb, offset, 1,
+                      ENC_LITTLE_ENDIAN);
+  proto_tree_add_item(tree, hf_ieee80211_ff_more_gas_fragments, tvb, offset, 1,
+                      ENC_LITTLE_ENDIAN);
+  return 1;
+}
+
+static guint
+add_ff_sa_query_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_sa_query_action_code, tvb, offset,
+                      1, ENC_LITTLE_ENDIAN);
+  return 1;
+}
+
+static guint
+add_ff_transaction_id(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_transaction_id, tvb, offset, 2,
+                      ENC_LITTLE_ENDIAN);
+  return 2;
+}
+
+static guint
+add_ff_tdls_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
+{
+  guint8 code;
+  code = tvb_get_guint8(tvb, offset);
+  col_set_str(pinfo->cinfo, COL_INFO,
+              val_to_str_ext_const(code, &tdls_action_codes_ext,
+                                   "Unknown TDLS Action"));
+  proto_tree_add_item(tree, hf_ieee80211_ff_tdls_action_code, tvb, offset, 1,
+                      ENC_LITTLE_ENDIAN);
+  return 1;
+}
+
+static guint
+add_ff_target_channel(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_target_channel, tvb, offset, 1,
+                      ENC_LITTLE_ENDIAN);
+  return 1;
+}
+
+static guint
+add_ff_operating_class(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_operating_class, tvb, offset, 1,
+                      ENC_LITTLE_ENDIAN);
+  return 1;
+}
+
+static guint
+add_ff_wnm_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
+{
+  guint8 code;
+
+  code = tvb_get_guint8(tvb, offset);
+  col_set_str(pinfo->cinfo, COL_INFO,
+              val_to_str_ext_const(code, &wnm_action_codes_ext, "Unknown WNM Action"));
+  proto_tree_add_item(tree, hf_ieee80211_ff_wnm_action_code, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+  return 1;
+}
+
+static guint
+add_ff_unprotected_wnm_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
+{
+  guint8 code;
+
+  code = tvb_get_guint8(tvb, offset);
+  col_set_str(pinfo->cinfo, COL_INFO,
+              val_to_str_ext_const(code, &unprotected_wnm_action_codes_ext, "Unknown Unprotected WNM Action"));
+  proto_tree_add_item(tree, hf_ieee80211_ff_unprotected_wnm_action_code, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+  return 1;
+}
+
+static guint
+add_ff_unprotected_dmg_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_unprotected_dmg_action_code, tvb, offset, 1, ENC_NA);
+  return 1;
+}
+
+static guint
+add_ff_key_data_length(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_key_data_length, tvb, offset, 2,
+                      ENC_LITTLE_ENDIAN);
+  return 2;
+}
+
+static guint
+add_ff_wnm_notification_type(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_wnm_notification_type,
+                      tvb, offset, 1, ENC_NA);
+  return 1;
+}
+
+/* Action frame: Radio Measurement actions */
+static guint
+add_ff_rm_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_rm_action_code, tvb, offset, 1, ENC_NA);
+  return 1;
+}
+
+static guint
+add_ff_rm_dialog_token(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_rm_dialog_token, tvb, offset, 1, ENC_NA);
+  return 1;
+}
+
+/* Radio Measurement Request frame, Action fields */
+static guint
+add_ff_rm_repetitions(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  /* Note: 65535 means repeated until cancelled or superseded */
+  proto_tree_add_item(tree, hf_ieee80211_ff_rm_repetitions, tvb, offset, 2,
+                      ENC_BIG_ENDIAN);
+  return 2;
+}
+
+/* Link Measurement Request frame, Action fields*/
+static guint
+add_ff_rm_tx_power(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  /* In dBm, see 8.4.1.20 */
+  proto_tree_add_item(tree, hf_ieee80211_ff_rm_tx_power, tvb, offset, 1, ENC_NA);
+  return 1;
+}
+
+static guint
+add_ff_rm_max_tx_power(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  /* In dBm, see 8.4.1.19 */
+  proto_tree_add_item(tree, hf_ieee80211_ff_rm_max_tx_power, tvb, offset, 1, ENC_NA);
+  return 1;
+}
+
+/* Link Measurement Report frame, Action fields */
+static guint
+add_ff_rm_tpc_report(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree *tpc_tree;
+  proto_item *tpc_item;
+
+  /* 8.4.2.19 TPC Report element */
+  tpc_item = proto_tree_add_item(tree, hf_ieee80211_ff_tpc, tvb, offset, 4, ENC_NA);
+  tpc_tree = proto_item_add_subtree(tpc_item, ett_tpc);
+  proto_tree_add_item(tpc_tree, hf_ieee80211_ff_tpc_element_id, tvb, offset, 1, ENC_NA);
+  proto_tree_add_item(tpc_tree, hf_ieee80211_ff_tpc_length, tvb, offset + 1, 1, ENC_NA);
+  proto_tree_add_item(tpc_tree, hf_ieee80211_ff_tpc_tx_power, tvb, offset + 2, 1, ENC_NA);
+  proto_tree_add_item(tpc_tree, hf_ieee80211_ff_tpc_link_margin, tvb, offset + 3, 1, ENC_NA);
+  return 4;
+}
+
+static guint
+add_ff_rm_rx_antenna_id(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  /* 8.4.2.42: 0 means unknown, 1-254 is valid, 255 means multiple antennas */
+  proto_tree_add_item(tree, hf_ieee80211_ff_rm_rx_antenna_id, tvb, offset, 1, ENC_NA);
+  return 1;
+}
+
+static guint
+add_ff_rm_tx_antenna_id(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  /* 8.4.2.42: 0 means unknown, 1-254 is valid, 255 means multiple antennas */
+  proto_tree_add_item(tree, hf_ieee80211_ff_rm_tx_antenna_id, tvb, offset, 1, ENC_NA);
+  return 1;
+}
+
+static guint
+add_ff_rm_rcpi(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  /* 8.4.2.40: RCPI as specified for certain PHYs */
+  proto_tree_add_item(tree, hf_ieee80211_ff_rm_rcpi, tvb, offset, 1, ENC_NA);
+  return 1;
+}
+
+static guint
+add_ff_rm_rsni(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  /* 8.4.2.43: RSNI in steps of 0.5 dB, calculated as:
+   * RSNI = (10 * log10((RCPI_{power} - ANPI_{power}) / ANPI_{power}) + 20)*2 */
+  proto_tree_add_item(tree, hf_ieee80211_ff_rm_rsni, tvb, offset, 1, ENC_NA);
+  return 1;
+}
+
+static guint
+add_ff_bss_transition_status_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_bss_transition_status_code, tvb, offset, 1,
+                      ENC_LITTLE_ENDIAN);
+  return 1;
+}
+
+static guint
+add_ff_bss_termination_delay(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
+{
+  proto_tree_add_item(tree, hf_ieee80211_ff_bss_termination_delay, tvb, offset, 1,
+                      ENC_LITTLE_ENDIAN);
+  return 1;
+}
+
+static guint
 add_ff_action_spectrum_mgmt(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
 {
     switch (tvb_get_guint8(tvb, offset + 1)) {
@@ -7605,18 +7717,18 @@ add_ff_action_spectrum_mgmt(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo,
     case SM_ACTION_MEASUREMENT_REPORT:
     case SM_ACTION_TPC_REQUEST:
     case SM_ACTION_TPC_REPORT:
-      add_fixed_field(tree, tvb, pinfo, offset,     FIELD_CATEGORY_CODE);
-      add_fixed_field(tree, tvb, pinfo, offset + 1, FIELD_ACTION_CODE);
-      add_fixed_field(tree, tvb, pinfo, offset + 2, FIELD_DIALOG_TOKEN);
+      add_ff_category_code(tree, tvb, pinfo, offset);
+      add_ff_action_code(tree, tvb, pinfo, offset + 1);
+      add_ff_dialog_token(tree, tvb, pinfo, offset + 2);
       return 3;
     case SM_ACTION_CHAN_SWITCH_ANNC:
     case SM_ACTION_EXT_CHAN_SWITCH_ANNC:
-      add_fixed_field(tree, tvb, pinfo, offset,     FIELD_CATEGORY_CODE);
-      add_fixed_field(tree, tvb, pinfo, offset + 1, FIELD_ACTION_CODE);
+      add_ff_category_code(tree, tvb, pinfo, offset);
+      add_ff_action_code(tree, tvb, pinfo, offset + 1);
       return 2;
     default:
-      add_fixed_field(tree, tvb, pinfo, offset,     FIELD_CATEGORY_CODE);
-      add_fixed_field(tree, tvb, pinfo, offset + 1, FIELD_ACTION_CODE);
+      add_ff_category_code(tree, tvb, pinfo, offset);
+      add_ff_action_code(tree, tvb, pinfo, offset + 1);
       return 2;
     }
 }
@@ -7626,32 +7738,32 @@ add_ff_action_qos(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offse
 {
   switch (tvb_get_guint8(tvb, offset + 1)) {
   case QOS_ACTION_ADDTS_REQUEST:
-    add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset + 1, FIELD_QOS_ACTION_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset + 2, FIELD_DIALOG_TOKEN);
+    add_ff_category_code(tree, tvb, pinfo, offset);
+    add_ff_qos_action_code(tree, tvb, pinfo, offset + 1);
+    add_ff_dialog_token(tree, tvb, pinfo, offset + 2);
     return 3;
   case QOS_ACTION_ADDTS_RESPONSE:
-    add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset + 1, FIELD_QOS_ACTION_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset + 2, FIELD_DIALOG_TOKEN);
-    add_fixed_field(tree, tvb, pinfo, offset + 3, FIELD_STATUS_CODE);
+    add_ff_category_code(tree, tvb, pinfo, offset);
+    add_ff_qos_action_code(tree, tvb, pinfo, offset + 1);
+    add_ff_dialog_token(tree, tvb, pinfo, offset + 2);
+    add_ff_status_code(tree, tvb, pinfo, offset + 3);
     return 5;
   case QOS_ACTION_DELTS:
-    add_fixed_field(tree, tvb, pinfo, offset,     FIELD_CATEGORY_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset + 1, FIELD_QOS_ACTION_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset + 2, FIELD_QOS_TS_INFO);
-    add_fixed_field(tree, tvb, pinfo, offset + 5, FIELD_REASON_CODE);
+    add_ff_category_code(tree, tvb, pinfo, offset);
+    add_ff_qos_action_code(tree, tvb, pinfo, offset + 1);
+    add_ff_qos_ts_info(tree, tvb, pinfo, offset + 2);
+    add_ff_reason_code(tree, tvb, pinfo, offset + 5);
     return 7;
   case QOS_ACTION_SCHEDULE:
-    add_fixed_field(tree, tvb, pinfo, offset,     FIELD_CATEGORY_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset + 1, FIELD_QOS_ACTION_CODE);
+    add_ff_category_code(tree, tvb, pinfo, offset);
+    add_ff_qos_action_code(tree, tvb, pinfo, offset + 1);
     return 2;
   case QOS_ACTION_MAP_CONFIGURE:
-    add_fixed_field(tree, tvb, pinfo, offset,     FIELD_CATEGORY_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset + 1, FIELD_QOS_ACTION_CODE);
+    add_ff_category_code(tree, tvb, pinfo, offset);
+    add_ff_qos_action_code(tree, tvb, pinfo, offset + 1);
     return 2;
   default:
-    add_fixed_field(tree, tvb, pinfo, offset,     FIELD_CATEGORY_CODE);
+    add_ff_category_code(tree, tvb, pinfo, offset);
     return 2;
   }
 }
@@ -7661,32 +7773,32 @@ add_ff_action_dls(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offse
 {
   switch (tvb_get_guint8(tvb, offset + 1)) {
   case DLS_ACTION_REQUEST:
-    add_fixed_field(tree, tvb, pinfo, offset,      FIELD_CATEGORY_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset +  1, FIELD_DLS_ACTION_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset +  2, FIELD_DST_MAC_ADDR);
-    add_fixed_field(tree, tvb, pinfo, offset +  8, FIELD_SRC_MAC_ADDR);
-    add_fixed_field(tree, tvb, pinfo, offset + 14, FIELD_CAP_INFO);
-    add_fixed_field(tree, tvb, pinfo, offset + 16, FIELD_DLS_TIMEOUT);
+    add_ff_category_code(tree, tvb, pinfo, offset);
+    add_ff_dls_action_code(tree, tvb, pinfo, offset +  1);
+    add_ff_dst_mac_addr(tree, tvb, pinfo, offset +  2);
+    add_ff_src_mac_addr(tree, tvb, pinfo, offset +  8);
+    add_ff_cap_info(tree, tvb, pinfo, offset + 14);
+    add_ff_dls_timeout(tree, tvb, pinfo, offset + 16);
     return 18;
   case DLS_ACTION_RESPONSE:
-    add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset +  1, FIELD_DLS_ACTION_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset +  2, FIELD_STATUS_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset +  4, FIELD_DST_MAC_ADDR);
-    add_fixed_field(tree, tvb, pinfo, offset + 10, FIELD_SRC_MAC_ADDR);
+    add_ff_category_code(tree, tvb, pinfo, offset);
+    add_ff_dls_action_code(tree, tvb, pinfo, offset +  1);
+    add_ff_status_code(tree, tvb, pinfo, offset +  2);
+    add_ff_dst_mac_addr(tree, tvb, pinfo, offset +  4);
+    add_ff_src_mac_addr(tree, tvb, pinfo, offset + 10);
     if (!hf_ieee80211_ff_status_code) {
-      add_fixed_field(tree, tvb, pinfo, offset + 16, FIELD_CAP_INFO);
+      add_ff_cap_info(tree, tvb, pinfo, offset + 16);
     }
     return 16;
   case DLS_ACTION_TEARDOWN:
-    add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset +  1, FIELD_DLS_ACTION_CODE);
-    add_fixed_field(tree, tvb, pinfo, offset +  2, FIELD_DST_MAC_ADDR);
-    add_fixed_field(tree, tvb, pinfo, offset +  8, FIELD_SRC_MAC_ADDR);
-    add_fixed_field(tree, tvb, pinfo, offset + 14, FIELD_REASON_CODE);
+    add_ff_category_code(tree, tvb, pinfo, offset);
+    add_ff_dls_action_code(tree, tvb, pinfo, offset +  1);
+    add_ff_dst_mac_addr(tree, tvb, pinfo, offset +  2);
+    add_ff_src_mac_addr(tree, tvb, pinfo, offset +  8);
+    add_ff_reason_code(tree, tvb, pinfo, offset + 14);
     return 16;
   default:
-    add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+    add_ff_category_code(tree, tvb, pinfo, offset);
     return 2;
   }
 }
@@ -7698,26 +7810,26 @@ add_ff_action_block_ack(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int
 
   switch (tvb_get_guint8(tvb, offset + 1)) {
   case BA_ADD_BLOCK_ACK_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_ACTION_CODE);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_PARAM);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_TIMEOUT);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_SSC);
+    offset += add_ff_category_code(tree, tvb, pinfo, offset);
+    offset += add_ff_block_ack_action_code(tree, tvb, pinfo, offset);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_block_ack_param(tree, tvb, pinfo, offset);
+    offset += add_ff_block_ack_timeout(tree, tvb, pinfo, offset);
+    offset += add_ff_block_ack_ssc(tree, tvb, pinfo, offset);
     break;
   case BA_ADD_BLOCK_ACK_RESPONSE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_ACTION_CODE);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_PARAM);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_TIMEOUT);
+    offset += add_ff_category_code(tree, tvb, pinfo, offset);
+    offset += add_ff_block_ack_action_code(tree, tvb, pinfo, offset);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_status_code(tree, tvb, pinfo, offset);
+    offset += add_ff_block_ack_param(tree, tvb, pinfo, offset);
+    offset += add_ff_block_ack_timeout(tree, tvb, pinfo, offset);
     break;
   case BA_DELETE_BLOCK_ACK:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_ACTION_CODE);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DELBA_PARAM_SET);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_REASON_CODE);
+    offset += add_ff_category_code(tree, tvb, pinfo, offset);
+    offset += add_ff_block_ack_action_code(tree, tvb, pinfo, offset);
+    offset += add_ff_delba_param_set(tree, tvb, pinfo, offset);
+    offset += add_ff_reason_code(tree, tvb, pinfo, offset);
     break;
   }
 
@@ -7759,30 +7871,30 @@ add_ff_action_public_fields(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo,
     }
     break;
   case PA_GAS_INITIAL_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
     offset += dissect_advertisement_protocol(pinfo, tree, tvb, offset,
                                              &anqp);
     offset += dissect_gas_initial_request(tree, tvb, pinfo, offset, anqp);
     break;
   case PA_GAS_INITIAL_RESPONSE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_GAS_COMEBACK_DELAY);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_status_code(tree, tvb, pinfo, offset);
+    offset += add_ff_gas_comeback_delay(tree, tvb, pinfo, offset);
     offset += dissect_advertisement_protocol(pinfo, tree, tvb, offset,
                                              &anqp);
     offset += dissect_gas_initial_response(tree, tvb, pinfo, offset, anqp);
     break;
   case PA_GAS_COMEBACK_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
     break;
   case PA_GAS_COMEBACK_RESPONSE:
     dialog_token = tvb_get_guint8(tvb, offset);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_status_code(tree, tvb, pinfo, offset);
     frag = tvb_get_guint8(tvb, offset) & 0x7f;
     more = (tvb_get_guint8(tvb, offset) & 0x80) != 0;
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_GAS_FRAGMENT_ID);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_GAS_COMEBACK_DELAY);
+    offset += add_ff_gas_fragment_id(tree, tvb, pinfo, offset);
+    offset += add_ff_gas_comeback_delay(tree, tvb, pinfo, offset);
     offset += dissect_advertisement_protocol(pinfo, tree, tvb, offset,
                                              &anqp);
     offset += dissect_gas_comeback_response(tree, tvb, pinfo, offset, anqp, frag,
@@ -7791,14 +7903,14 @@ add_ff_action_public_fields(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo,
   case PA_TDLS_DISCOVERY_RESPONSE:
     col_set_str(pinfo->cinfo, COL_PROTOCOL, "TDLS");
     col_set_str(pinfo->cinfo, COL_INFO, "TDLS Discovery Response");
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CAP_INFO);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_cap_info(tree, tvb, pinfo, offset);
     break;
   case PA_QAB_REQUEST:
   case PA_QAB_RESPONSE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_REQ_AP_ADDR);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RES_AP_ADDR);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_req_ap_addr(tree, tvb, pinfo, offset);
+    offset += add_ff_res_ap_addr(tree, tvb, pinfo, offset);
     break;
   }
 
@@ -7810,9 +7922,9 @@ add_ff_action_public(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int of
 {
   guint8 code;
   guint start = offset;
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   code    = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_PA_ACTION_CODE);
+  offset += add_ff_pa_action_code(tree, tvb, pinfo, offset);
   offset += add_ff_action_public_fields(tree, tvb, pinfo, offset, code);
   return offset - start;
 }
@@ -7822,9 +7934,9 @@ add_ff_action_protected_public(proto_tree *tree, tvbuff_t *tvb, packet_info *pin
 {
   guint8 code;
   guint start = offset;
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   code    = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_PPA_ACTION_CODE);
+  offset += add_ff_ppa_action_code(tree, tvb, pinfo, offset);
   offset += add_ff_action_public_fields(tree, tvb, pinfo, offset, code);
   return offset - start;
 }
@@ -7835,41 +7947,41 @@ add_ff_action_radio_measurement(proto_tree *tree, tvbuff_t *tvb, packet_info *pi
   guint  start = offset;
   guint8 code;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   code = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_ACTION_CODE);
+  offset += add_ff_rm_action_code(tree, tvb, pinfo, offset);
 
   switch (code) {
   case RM_ACTION_RADIO_MEASUREMENT_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_REPETITIONS);
+    offset += add_ff_rm_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_rm_repetitions(tree, tvb, pinfo, offset);
     /* Followed by Measurement Request Elements */
     break;
   case RM_ACTION_RADIO_MEASUREMENT_REPORT:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_DIALOG_TOKEN);
+    offset += add_ff_rm_dialog_token(tree, tvb, pinfo, offset);
     /* Followed by Measurement Report Elements */
     break;
   case RM_ACTION_LINK_MEASUREMENT_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_TX_POWER);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_MAX_TX_POWER);
+    offset += add_ff_rm_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_rm_tx_power(tree, tvb, pinfo, offset);
+    offset += add_ff_rm_max_tx_power(tree, tvb, pinfo, offset);
     /* Followed by Optional Subelements */
     break;
   case RM_ACTION_LINK_MEASUREMENT_REPORT:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_TPC_REPORT);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_RX_ANTENNA_ID);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_TX_ANTENNA_ID);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_RCPI);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_RSNI);
+    offset += add_ff_rm_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_rm_tpc_report(tree, tvb, pinfo, offset);
+    offset += add_ff_rm_rx_antenna_id(tree, tvb, pinfo, offset);
+    offset += add_ff_rm_tx_antenna_id(tree, tvb, pinfo, offset);
+    offset += add_ff_rm_rcpi(tree, tvb, pinfo, offset);
+    offset += add_ff_rm_rsni(tree, tvb, pinfo, offset);
     /* Followed by Optional Subelements */
     break;
   case RM_ACTION_NEIGHBOR_REPORT_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_DIALOG_TOKEN);
+    offset += add_ff_rm_dialog_token(tree, tvb, pinfo, offset);
     /* Followed by Optional Subelements */
     break;
   case RM_ACTION_NEIGHBOR_REPORT_RESPONSE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_DIALOG_TOKEN);
+    offset += add_ff_rm_dialog_token(tree, tvb, pinfo, offset);
     /* Followed by Neighbor Report Elements */
     break;
   }
@@ -7883,31 +7995,31 @@ add_ff_action_fast_bss_transition(proto_tree *tree, tvbuff_t *tvb, packet_info *
   guint  start = offset;
   guint8 code;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   code    = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_FT_ACTION_CODE);
+  offset += add_ff_ft_action_code(tree, tvb, pinfo, offset);
 
   switch (code) {
   case FT_ACTION_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STA_ADDRESS);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TARGET_AP_ADDRESS);
+    offset += add_ff_sta_address(tree, tvb, pinfo, offset);
+    offset += add_ff_target_ap_address(tree, tvb, pinfo, offset);
     /* Followed by FT Request frame body (IEs) */
     break;
   case FT_ACTION_RESPONSE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STA_ADDRESS);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TARGET_AP_ADDRESS);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+    offset += add_ff_sta_address(tree, tvb, pinfo, offset);
+    offset += add_ff_target_ap_address(tree, tvb, pinfo, offset);
+    offset += add_ff_status_code(tree, tvb, pinfo, offset);
     /* Followed by FT Response frame body (IEs) */
     break;
   case FT_ACTION_CONFIRM:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STA_ADDRESS);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TARGET_AP_ADDRESS);
+    offset += add_ff_sta_address(tree, tvb, pinfo, offset);
+    offset += add_ff_target_ap_address(tree, tvb, pinfo, offset);
     /* Followed by FT Confirm frame body (IEs) */
     break;
   case FT_ACTION_ACK:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STA_ADDRESS);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TARGET_AP_ADDRESS);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+    offset += add_ff_sta_address(tree, tvb, pinfo, offset);
+    offset += add_ff_target_ap_address(tree, tvb, pinfo, offset);
+    offset += add_ff_status_code(tree, tvb, pinfo, offset);
     /* Followed by FT Ack frame body (IEs) */
     break;
   }
@@ -7921,16 +8033,16 @@ add_ff_action_sa_query(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int
   guint  start = offset;
   guint8 code;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   code    = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_SA_QUERY_ACTION_CODE);
+  offset += add_ff_sa_query_action_code(tree, tvb, pinfo, offset);
 
   switch (code) {
   case SA_QUERY_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TRANSACTION_ID);
+    offset += add_ff_transaction_id(tree, tvb, pinfo, offset);
     break;
   case SA_QUERY_RESPONSE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TRANSACTION_ID);
+    offset += add_ff_transaction_id(tree, tvb, pinfo, offset);
     break;
   }
 
@@ -7942,15 +8054,15 @@ add_ff_action_mesh(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offs
 {
   guint length;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_MESH_ACTION);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
+  offset += add_ff_mesh_action(tree, tvb, pinfo, offset);
   /* The only fixed fields are the category and mesh action.  The rest are IEs.
    */
   length = 2;
   if (tvb_get_guint8(tvb, 1) == MESH_ACTION_TBTT_ADJ_RESPONSE) {
     /* ..except for the TBTT Adjustment Response, which has a status code field
      */
-    length += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+    length += add_ff_status_code(tree, tvb, pinfo, offset);
   }
   return length;
 }
@@ -7960,9 +8072,9 @@ add_ff_action_multihop(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int
 {
   guint start = offset;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_MULTIHOP_ACTION);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_MESH_CONTROL);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
+  offset += add_ff_multihop_action(tree, tvb, pinfo, offset);
+  offset += add_ff_mesh_control(tree, tvb, pinfo, offset);
   return offset - start;
 }
 
@@ -7971,16 +8083,16 @@ add_ff_action_self_protected(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo
 {
   guint start = offset;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_SELFPROT_ACTION);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
+  offset += add_ff_selfprot_action(tree, tvb, pinfo, offset);
 
   switch (tvb_get_guint8(tvb, start + 1)) {
   case SELFPROT_ACTION_MESH_PEERING_OPEN:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CAP_INFO);
+    offset += add_ff_cap_info(tree, tvb, pinfo, offset);
     break;
   case SELFPROT_ACTION_MESH_PEERING_CONFIRM:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CAP_INFO);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_ASSOC_ID);
+    offset += add_ff_cap_info(tree, tvb, pinfo, offset);
+    offset += add_ff_assoc_id(tree, tvb, pinfo, offset);
     break;
   }
 
@@ -8003,7 +8115,7 @@ wnm_bss_trans_mgmt_req(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int
   guint8 mode;
   gint   left;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+  offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
 
   mode = tvb_get_guint8(tvb, offset);
   proto_tree_add_item(tree, hf_ieee80211_ff_request_mode_pref_cand,
@@ -8061,10 +8173,10 @@ wnm_bss_trans_mgmt_resp(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int
   guint8 code;
   gint   left;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+  offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
   code = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BSS_TRANSITION_STATUS_CODE);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BSS_TERMINATION_DELAY);
+  offset += add_ff_bss_transition_status_code(tree, tvb, pinfo, offset);
+  offset += add_ff_bss_termination_delay(tree, tvb, pinfo, offset);
   if (!code) {
     proto_tree_add_item(tree, hf_ieee80211_ff_target_bss,
                         tvb, offset, 6, ENC_NA);
@@ -8084,7 +8196,7 @@ static guint
 wnm_sleep_mode_req(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
 {
   int start = offset;
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+  offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
   return offset - start;
 }
 
@@ -8095,9 +8207,9 @@ wnm_sleep_mode_resp(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int off
   guint16 key_data_len;
   gint left;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+  offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
   key_data_len = tvb_get_letohs(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_KEY_DATA_LENGTH);
+  offset += add_ff_key_data_length(tree, tvb, pinfo, offset);
   left = tvb_reported_length_remaining(tvb, offset);
   if (left < key_data_len) {
     expert_add_info(pinfo, tree, &ei_ieee80211_tag_wnm_sleep_mode_no_key_data);
@@ -8113,7 +8225,7 @@ static guint
 wnm_tfs_req(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
 {
   int start = offset;
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+  offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
   return offset - start;
 }
 
@@ -8121,7 +8233,7 @@ static guint
 wnm_tfs_resp(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
 {
   int start = offset;
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+  offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
   return offset - start;
 }
 
@@ -8129,8 +8241,8 @@ static guint
 wnm_notification_req(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
 {
   int start = offset;
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_WNM_NOTIFICATION_TYPE);
+  offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+  offset += add_ff_wnm_notification_type(tree, tvb, pinfo, offset);
   return offset - start;
 }
 
@@ -8140,9 +8252,9 @@ add_ff_action_wnm(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offse
   guint8 code;
   guint  start = offset;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   code    = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_WNM_ACTION_CODE);
+  offset += add_ff_wnm_action_code(tree, tvb, pinfo, offset);
   switch (code) {
   case WNM_BSS_TRANS_MGMT_REQ:
     offset += wnm_bss_trans_mgmt_req(tree, tvb, pinfo, offset);
@@ -8176,22 +8288,22 @@ add_ff_action_unprotected_wnm(proto_tree *tree, tvbuff_t *tvb, packet_info *pinf
   guint8 code;
   guint  start = offset;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   code    = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_UNPROTECTED_WNM_ACTION_CODE);
+  offset += add_ff_unprotected_wnm_action_code(tree, tvb, pinfo, offset);
 
   switch (code) {
   case UNPROTECTED_WNM_TIM:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CHECK_BEACON);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TIMESTAMP);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TOD);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TOA);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_MAX_TOD_ERR);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_MAX_TOA_ERR);
+    offset += add_ff_check_beacon(tree, tvb, pinfo, offset);
+    offset += add_ff_timestamp(tree, tvb, pinfo, offset);
+    offset += add_ff_tod(tree, tvb, pinfo, offset);
+    offset += add_ff_toa(tree, tvb, pinfo, offset);
+    offset += add_ff_max_tod_err(tree, tvb, pinfo, offset);
+    offset += add_ff_max_toa_err(tree, tvb, pinfo, offset);
     break;
   case UNPROTECTED_WNM_TIMING_MEASUREMENT:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_FOLLOWUP_DIALOG_TOKEN);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_followup_dialog_token(tree, tvb, pinfo, offset);
     break;
   }
 
@@ -8205,62 +8317,62 @@ add_ff_action_tdls(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offs
   guint16 status;
   guint   start = offset;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   code = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TDLS_ACTION_CODE);
+  offset += add_ff_tdls_action_code(tree, tvb, pinfo, offset);
   switch (code) {
   case TDLS_SETUP_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CAP_INFO);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_cap_info(tree, tvb, pinfo, offset);
     break;
   case TDLS_SETUP_RESPONSE:
     status = tvb_get_letohs(tvb, offset);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+    offset += add_ff_status_code(tree, tvb, pinfo, offset);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
     if (tvb_reported_length_remaining(tvb, offset) < 2) {
       if (status == 0) {
         expert_add_info(pinfo, tree, &ei_ieee80211_tdls_setup_response_malformed);
       }
       break;
     }
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CAP_INFO);
+    offset += add_ff_cap_info(tree, tvb, pinfo, offset);
     break;
   case TDLS_SETUP_CONFIRM:
     status = tvb_get_letohs(tvb, offset);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+    offset += add_ff_status_code(tree, tvb, pinfo, offset);
     if (tvb_reported_length_remaining(tvb, offset) < 1) {
       if (status == 0) {
         expert_add_info(pinfo, tree, &ei_ieee80211_tdls_setup_confirm_malformed);
       }
       break;
     }
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
     break;
   case TDLS_TEARDOWN:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_REASON_CODE);
+    offset += add_ff_reason_code(tree, tvb, pinfo, offset);
     break;
   case TDLS_PEER_TRAFFIC_INDICATION:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
     break;
   case TDLS_CHANNEL_SWITCH_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TARGET_CHANNEL);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_OPERATING_CLASS);
+    offset += add_ff_target_channel(tree, tvb, pinfo, offset);
+    offset += add_ff_operating_class(tree, tvb, pinfo, offset);
     break;
   case TDLS_CHANNEL_SWITCH_RESPONSE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+    offset += add_ff_status_code(tree, tvb, pinfo, offset);
     break;
   case TDLS_PEER_PSM_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
     break;
   case TDLS_PEER_PSM_RESPONSE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+    offset += add_ff_status_code(tree, tvb, pinfo, offset);
     break;
   case TDLS_PEER_TRAFFIC_RESPONSE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
     break;
   case TDLS_DISCOVERY_REQUEST:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+    offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
     break;
   }
 
@@ -8272,10 +8384,10 @@ add_ff_action_mgmt_notification(proto_tree *tree, tvbuff_t *tvb, packet_info *pi
 {
   guint start = offset;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_WME_ACTION_CODE);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_WME_STATUS_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
+  offset += add_ff_wme_action_code(tree, tvb, pinfo, offset);
+  offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+  offset += add_ff_wme_status_code(tree, tvb, pinfo, offset);
 
   return offset - start;  /* Size of fixed fields */
 }
@@ -8287,7 +8399,7 @@ add_ff_action_vendor_specific(proto_tree *tree, tvbuff_t *tvb, packet_info *pinf
   guint32 oui;
   guint8  subtype;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   oui = tvb_get_ntoh24(tvb, offset);
   proto_tree_add_item(tree, hf_ieee80211_tag_oui, tvb, offset, 3, ENC_NA);
   offset += 3;
@@ -8318,49 +8430,49 @@ add_ff_action_ht(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset
   guint8 n_sta, i;
   mimo_control_t mimo_cntrl;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_HT_ACTION_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
+  offset += add_ff_ht_action_code(tree, tvb, pinfo, offset);
 
   switch (tvb_get_guint8(tvb, offset - 1)) {
   case HT_ACTION_NOTIFY_CHAN_WIDTH:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CHANNEL_WIDTH);
+    offset += add_ff_channel_width(tree, tvb, pinfo, offset);
     break;
   case HT_ACTION_SM_PWR_SAVE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_SM_PWR_CNTRL);
+    offset += add_ff_sm_pwr_cntrl(tree, tvb, pinfo, offset);
     break;
   case HT_ACTION_PSMP_ACTION:
     n_sta = tvb_get_guint8(tvb, offset);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_PSMP_PARAM_SET);
+    offset += add_ff_psmp_param_set(tree, tvb, pinfo, offset);
     for (i = 0; i < (n_sta & 0x0F); i++) {
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_PSMP_STA_INFO);
+      offset += add_ff_psmp_sta_info(tree, tvb, pinfo, offset);
     }
     break;
   case HT_ACTION_SET_PCO_PHASE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_PCO_PHASE_CNTRL);
+    offset += add_ff_pco_phase_cntrl(tree, tvb, pinfo, offset);
     break;
   case HT_ACTION_MIMO_CSI:
     mimo_cntrl = get_mimo_control(tvb, offset);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_MIMO_CNTRL);
+    offset += add_ff_mimo_cntrl(tree, tvb, pinfo, offset);
     offset += add_mimo_csi_matrices_report(tree, tvb, offset, mimo_cntrl);
     break;
   case HT_ACTION_MIMO_BEAMFORMING:
     mimo_cntrl = get_mimo_control(tvb, offset);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_MIMO_CNTRL);
+    offset += add_ff_mimo_cntrl(tree, tvb, pinfo, offset);
     offset += add_mimo_beamforming_feedback_report(tree, tvb, offset,
                                                    mimo_cntrl);
     break;
   case HT_ACTION_MIMO_COMPRESSED_BEAMFORMING:
     mimo_cntrl = get_mimo_control(tvb, offset);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_MIMO_CNTRL);
+    offset += add_ff_mimo_cntrl(tree, tvb, pinfo, offset);
     offset += add_mimo_compressed_beamforming_feedback_report(tree, tvb,
                                                               offset,
                                                               mimo_cntrl);
     break;
   case HT_ACTION_ANT_SEL_FEEDBACK:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_ANT_SELECTION);
+    offset += add_ff_ant_selection(tree, tvb, pinfo, offset);
     break;
   case HT_ACTION_HT_INFO_EXCHANGE:
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_HT_INFORMATION);
+    offset += add_ff_ht_information(tree, tvb, pinfo, offset);
     break;
   }
 
@@ -8368,237 +8480,6 @@ add_ff_action_ht(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset
 }
 
 static guint
-add_ff_ft_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_ft_action_code, tvb, offset, 1,
-                      ENC_LITTLE_ENDIAN);
-  return 1;
-}
-
-static guint
-add_ff_sta_address(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_sta_address, tvb, offset, 6,
-                      ENC_NA);
-  return 6;
-}
-
-static guint
-add_ff_target_ap_address(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_target_ap_address, tvb, offset, 6,
-                      ENC_NA);
-  return 6;
-}
-
-static guint
-add_ff_gas_comeback_delay(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_gas_comeback_delay, tvb, offset, 2,
-                      ENC_LITTLE_ENDIAN);
-  return 2;
-}
-
-static guint
-add_ff_gas_fragment_id(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_gas_fragment_id, tvb, offset, 1,
-                      ENC_LITTLE_ENDIAN);
-  proto_tree_add_item(tree, hf_ieee80211_ff_more_gas_fragments, tvb, offset, 1,
-                      ENC_LITTLE_ENDIAN);
-  return 1;
-}
-
-static guint
-add_ff_sa_query_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_sa_query_action_code, tvb, offset,
-                      1, ENC_LITTLE_ENDIAN);
-  return 1;
-}
-
-static guint
-add_ff_transaction_id(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_transaction_id, tvb, offset, 2,
-                      ENC_LITTLE_ENDIAN);
-  return 2;
-}
-
-static guint
-add_ff_tdls_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
-{
-  guint8 code;
-  code = tvb_get_guint8(tvb, offset);
-  col_set_str(pinfo->cinfo, COL_INFO,
-              val_to_str_ext_const(code, &tdls_action_codes_ext,
-                                   "Unknown TDLS Action"));
-  proto_tree_add_item(tree, hf_ieee80211_ff_tdls_action_code, tvb, offset, 1,
-                      ENC_LITTLE_ENDIAN);
-  return 1;
-}
-
-static guint
-add_ff_target_channel(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_target_channel, tvb, offset, 1,
-                      ENC_LITTLE_ENDIAN);
-  return 1;
-}
-
-static guint
-add_ff_operating_class(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_operating_class, tvb, offset, 1,
-                      ENC_LITTLE_ENDIAN);
-  return 1;
-}
-
-static guint
-add_ff_wnm_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
-{
-  guint8 code;
-
-  code = tvb_get_guint8(tvb, offset);
-  col_set_str(pinfo->cinfo, COL_INFO,
-              val_to_str_ext_const(code, &wnm_action_codes_ext, "Unknown WNM Action"));
-  proto_tree_add_item(tree, hf_ieee80211_ff_wnm_action_code, tvb, offset, 1, ENC_LITTLE_ENDIAN);
-  return 1;
-}
-
-static guint
-add_ff_unprotected_wnm_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
-{
-  guint8 code;
-
-  code = tvb_get_guint8(tvb, offset);
-  col_set_str(pinfo->cinfo, COL_INFO,
-              val_to_str_ext_const(code, &unprotected_wnm_action_codes_ext, "Unknown Unprotected WNM Action"));
-  proto_tree_add_item(tree, hf_ieee80211_ff_unprotected_wnm_action_code, tvb, offset, 1, ENC_LITTLE_ENDIAN);
-  return 1;
-}
-
-static guint
-add_ff_unprotected_dmg_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_unprotected_dmg_action_code, tvb, offset, 1, ENC_NA);
-  return 1;
-}
-
-static guint
-add_ff_key_data_length(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_key_data_length, tvb, offset, 2,
-                      ENC_LITTLE_ENDIAN);
-  return 2;
-}
-
-struct ieee80211_fixed_field_dissector {
-  enum fixed_field lfcode;
-  guint (*dissector)(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset);
-};
-
-static guint
-add_ff_wnm_notification_type(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_wnm_notification_type,
-                      tvb, offset, 1, ENC_NA);
-  return 1;
-}
-
-/* Action frame: Radio Measurement actions */
-static guint
-add_ff_rm_action_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_rm_action_code, tvb, offset, 1, ENC_NA);
-  return 1;
-}
-
-static guint
-add_ff_rm_dialog_token(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_rm_dialog_token, tvb, offset, 1, ENC_NA);
-  return 1;
-}
-
-/* Radio Measurement Request frame, Action fields */
-static guint
-add_ff_rm_repetitions(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  /* Note: 65535 means repeated until cancelled or superseded */
-  proto_tree_add_item(tree, hf_ieee80211_ff_rm_repetitions, tvb, offset, 2,
-                      ENC_BIG_ENDIAN);
-  return 2;
-}
-
-/* Link Measurement Request frame, Action fields*/
-static guint
-add_ff_rm_tx_power(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  /* In dBm, see 8.4.1.20 */
-  proto_tree_add_item(tree, hf_ieee80211_ff_rm_tx_power, tvb, offset, 1, ENC_NA);
-  return 1;
-}
-
-static guint
-add_ff_rm_max_tx_power(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  /* In dBm, see 8.4.1.19 */
-  proto_tree_add_item(tree, hf_ieee80211_ff_rm_max_tx_power, tvb, offset, 1, ENC_NA);
-  return 1;
-}
-
-/* Link Measurement Report frame, Action fields */
-static guint
-add_ff_rm_tpc_report(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree *tpc_tree;
-  proto_item *tpc_item;
-
-  /* 8.4.2.19 TPC Report element */
-  tpc_item = proto_tree_add_item(tree, hf_ieee80211_ff_tpc, tvb, offset, 4, ENC_NA);
-  tpc_tree = proto_item_add_subtree(tpc_item, ett_tpc);
-  proto_tree_add_item(tpc_tree, hf_ieee80211_ff_tpc_element_id, tvb, offset, 1, ENC_NA);
-  proto_tree_add_item(tpc_tree, hf_ieee80211_ff_tpc_length, tvb, offset + 1, 1, ENC_NA);
-  proto_tree_add_item(tpc_tree, hf_ieee80211_ff_tpc_tx_power, tvb, offset + 2, 1, ENC_NA);
-  proto_tree_add_item(tpc_tree, hf_ieee80211_ff_tpc_link_margin, tvb, offset + 3, 1, ENC_NA);
-  return 4;
-}
-
-static guint
-add_ff_rm_rx_antenna_id(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  /* 8.4.2.42: 0 means unknown, 1-254 is valid, 255 means multiple antennas */
-  proto_tree_add_item(tree, hf_ieee80211_ff_rm_rx_antenna_id, tvb, offset, 1, ENC_NA);
-  return 1;
-}
-
-static guint
-add_ff_rm_tx_antenna_id(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  /* 8.4.2.42: 0 means unknown, 1-254 is valid, 255 means multiple antennas */
-  proto_tree_add_item(tree, hf_ieee80211_ff_rm_tx_antenna_id, tvb, offset, 1, ENC_NA);
-  return 1;
-}
-
-static guint
-add_ff_rm_rcpi(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  /* 8.4.2.40: RCPI as specified for certain PHYs */
-  proto_tree_add_item(tree, hf_ieee80211_ff_rm_rcpi, tvb, offset, 1, ENC_NA);
-  return 1;
-}
-
-static guint
-add_ff_rm_rsni(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  /* 8.4.2.43: RSNI in steps of 0.5 dB, calculated as:
-   * RSNI = (10 * log10((RCPI_{power} - ANPI_{power}) / ANPI_{power}) + 20)*2 */
-  proto_tree_add_item(tree, hf_ieee80211_ff_rm_rsni, tvb, offset, 1, ENC_NA);
-  return 1;
-}
-
-static guint
 add_ff_beacon_interval_ctrl(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
 {
   proto_item *bic_item = proto_tree_add_item(tree, hf_ieee80211_ff_bic, tvb, offset, 6, ENC_LITTLE_ENDIAN);
@@ -8893,6 +8774,7 @@ add_tag_relay_capabilities(packet_info *pinfo, proto_item *item, gint32 tag_len,
   return;
 }
 
+#if 0
 static guint
 add_ff_relay_capable_sta_info(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
 {
@@ -8903,7 +8785,7 @@ add_ff_relay_capable_sta_info(proto_tree *tree, tvbuff_t *tvb, packet_info *pinf
   add_tag_relay_capabilities(pinfo, rcsi_item, 2, rcsi_tree, tvb, &offset);
   return 3;
 }
-
+#endif
 
 static void
 dissect_ieee80211_extension(guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
@@ -8926,14 +8808,14 @@ dissect_ieee80211_extension(guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, prot
       gboolean cc, dis;
       guint16 bic_field;
       fixed_tree = get_fixed_parameter_tree (ext_tree, tvb, offset, 20);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_TIMESTAMP);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_SECTOR_SWEEP);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_BEACON_INTERVAL);
+      offset += add_ff_timestamp(fixed_tree, tvb, pinfo, offset);
+      offset += add_ff_sector_sweep(fixed_tree, tvb, pinfo, offset);
+      offset += add_ff_beacon_interval(fixed_tree, tvb, pinfo, offset);
       bic_field = tvb_get_letohs(tvb, offset);
       cc = (bic_field & 0x1);
       dis  = (bic_field & 0x2) >> 1;
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_BEACON_INTERVAL_CTRL);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_DMG_PARAMETERS);
+      offset += add_ff_beacon_interval_ctrl(fixed_tree, tvb, pinfo, offset);
+      offset += add_ff_dmg_params(fixed_tree, tvb, pinfo, offset);
       if(cc) {
         offset += add_ff_cc_field(fixed_tree,tvb, offset, dis);
       }
@@ -8958,17 +8840,17 @@ add_ff_action_unprotected_dmg(proto_tree *tree, tvbuff_t *tvb, packet_info *pinf
   guint8 code;
   guint  start = offset;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   code    = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_UNPROTECTED_DMG_ACTION_CODE);
+  offset += add_ff_unprotected_dmg_action_code(tree, tvb, pinfo, offset);
   switch (code) {
     case UNPROTECTED_DMG_ANNOUNCE:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TIMESTAMP);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BEACON_INTERVAL);
+      offset += add_ff_timestamp(tree, tvb, pinfo, offset);
+      offset += add_ff_beacon_interval(tree, tvb, pinfo, offset);
       break;
     case UNPROTECTED_DMG_BRP:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_BRP_REQ);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_BRP_request(tree, tvb, pinfo, offset);
       break;
   }
   return offset - start;
@@ -9219,10 +9101,10 @@ add_ff_action_vht(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offse
   proto_item *ti;
   proto_tree *ti_tree;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
 
   vht_action = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_VHT_ACTION);
+  offset += add_ff_vht_action(tree, tvb, pinfo, offset);
 
   switch(vht_action){
     case VHT_ACT_VHT_COMPRESSED_BEAMFORMING:{
@@ -9265,31 +9147,31 @@ add_ff_action_fst(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offse
   guint8 code;
   guint  start = offset;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   code    = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_FST_ACTION_CODE);
+  offset += add_ff_fst_action_code(tree, tvb, pinfo, offset);
   switch (code) {
     case FST_SETUP_REQUEST:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_LLT);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_llt(tree, tvb, pinfo, offset);
       break;
     case FST_SETUP_RESPONSE:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_status_code(tree, tvb, pinfo, offset);
       break;
     case FST_TEAR_DOWN:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_FSTS_ID);
+      offset += add_ff_fsts_id(tree, tvb, pinfo, offset);
       break;
     case FST_ACK_REQUEST:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_FSTS_ID);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_fsts_id(tree, tvb, pinfo, offset);
       break;
     case FST_ACK_RESPONSE:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_FSTS_ID);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_fsts_id(tree, tvb, pinfo, offset);
       break;
     case FST_ON_CHANNEL_TUNNEL_REQUEST:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_OCT_MMPDU);
+      offset += add_ff_oct_mmpdu(tree, tvb, pinfo, offset);
       break;
   }
   return offset - start;
@@ -9302,51 +9184,51 @@ add_ff_action_dmg(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offse
   guint  start = offset;
   int left_offset;
 
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  offset += add_ff_category_code(tree, tvb, pinfo, offset);
   code    = tvb_get_guint8(tvb, offset);
-  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DMG_ACTION_CODE);
+  offset += add_ff_dmg_action_code(tree, tvb, pinfo, offset);
   switch (code) {
     case DMG_ACTION_PWR_SAVE_CONFIG_REQ:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DMG_PWR_MGMT);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_dmg_pwr_mgmt(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_PWR_SAVE_CONFIG_RES:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_status_code(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_INFO_REQ:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_SUBJECT_ADDRESS);
+      offset += add_ff_subject_address(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_INFO_RES:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_SUBJECT_ADDRESS);
+      offset += add_ff_subject_address(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_HANDOVER_REQ:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_HANDOVER_REASON);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_HANDOVER_REMAINING_BI);
+      offset += add_ff_handover_reason(tree, tvb, pinfo, offset);
+      offset += add_ff_handover_remaining_bi(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_HANDOVER_RES:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_HANDOVER_RESULT);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_HANDOVER_REJECT_REASON);
+      offset += add_ff_handover_result(tree, tvb, pinfo, offset);
+      offset += add_ff_handover_reject_reason(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_DTP_REQ:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_DTP_RES:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_RELAY_SEARCH_REQ:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DESTINATION_REDS_AID);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_destination_reds_aid(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_RELAY_SEARCH_RES:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_status_code(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_MUL_RELAY_CHANNEL_MEASURE_REQ:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_MUL_RELAY_CHANNEL_MEASURE_RES:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
       left_offset =
           tvb_reported_length_remaining(tvb, offset);
       while(left_offset > 0) {
@@ -9360,47 +9242,47 @@ add_ff_action_dmg(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offse
       }
       break;
     case DMG_ACTION_RLS_REQ:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DESTINATION_AID);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_REALY_AID);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_SOURCE_AID);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_destination_aid(tree, tvb, pinfo, offset);
+      offset += add_ff_realy_aid(tree, tvb, pinfo, offset);
+      offset += add_ff_source_aid(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_RLS_RES:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_RLS_ANNOUNCE:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DESTINATION_AID);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_REALY_AID);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_SOURCE_AID);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_status_code(tree, tvb, pinfo, offset);
+      offset += add_ff_destination_aid(tree, tvb, pinfo, offset);
+      offset += add_ff_realy_aid(tree, tvb, pinfo, offset);
+      offset += add_ff_source_aid(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_RLS_TEARDOWN:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DESTINATION_AID);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_REALY_AID);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_SOURCE_AID);
+      offset += add_ff_destination_aid(tree, tvb, pinfo, offset);
+      offset += add_ff_realy_aid(tree, tvb, pinfo, offset);
+      offset += add_ff_source_aid(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_RELAY_ACK_REQ:
     case DMG_ACTION_RELAY_ACK_RES:
       break;
     case DMG_ACTION_TPA_REQ:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_TIMING_OFFSET);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_SAMPLING_FREQUENCY_OFFSET);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_timing_offset(tree, tvb, pinfo, offset);
+      offset += add_ff_sampling_frequency_offset(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_TPA_RES:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_TPA_REP:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+      offset += add_ff_status_code(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_ROC_REQ:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RELAY_OPERATION_TYPE);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_relay_operation_type(tree, tvb, pinfo, offset);
       break;
     case DMG_ACTION_ROC_RES:
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_DIALOG_TOKEN);
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_STATUS_CODE);
+      offset += add_ff_dialog_token(tree, tvb, pinfo, offset);
+      offset += add_ff_status_code(tree, tvb, pinfo, offset);
       break;
   }
   return offset - start;
@@ -9459,164 +9341,11 @@ add_ff_action(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
   case CAT_VENDOR_SPECIFIC:  /* Vendor Specific Protected Category - 127 */
     return add_ff_action_vendor_specific(tree, tvb, pinfo, offset);
   default:
-    add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+    add_ff_category_code(tree, tvb, pinfo, offset);
     return 1;
   }
 }
 
-static guint
-add_ff_bss_transition_status_code(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_bss_transition_status_code, tvb, offset, 1,
-                      ENC_LITTLE_ENDIAN);
-  return 1;
-}
-
-static guint
-add_ff_bss_termination_delay(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, int offset)
-{
-  proto_tree_add_item(tree, hf_ieee80211_ff_bss_termination_delay, tvb, offset, 1,
-                      ENC_LITTLE_ENDIAN);
-  return 1;
-}
-
-#define FF_FIELD(f, func) { FIELD_ ## f, add_ff_ ## func }
-
-static const struct ieee80211_fixed_field_dissector ff_dissectors[] = {
-  FF_FIELD(TIMESTAMP                             , timestamp),
-  FF_FIELD(BEACON_INTERVAL                       , beacon_interval),
-  FF_FIELD(CAP_INFO                              , cap_info),
-  FF_FIELD(AUTH_ALG                              , auth_alg),
-  FF_FIELD(AUTH_TRANS_SEQ                        , auth_trans_seq),
-  FF_FIELD(CURRENT_AP_ADDR                       , current_ap_addr),
-  FF_FIELD(LISTEN_IVAL                           , listen_ival),
-  FF_FIELD(REASON_CODE                           , reason_code),
-  FF_FIELD(ASSOC_ID                              , assoc_id),
-  FF_FIELD(STATUS_CODE                           , status_code),
-  FF_FIELD(CATEGORY_CODE                         , category_code),
-  FF_FIELD(ACTION_CODE                           , action_code),
-  FF_FIELD(DIALOG_TOKEN                          , dialog_token),
-  FF_FIELD(FOLLOWUP_DIALOG_TOKEN                 , followup_dialog_token),
-  FF_FIELD(WME_ACTION_CODE                       , wme_action_code),
-  FF_FIELD(WME_STATUS_CODE                       , wme_status_code),
-  FF_FIELD(QOS_ACTION_CODE                       , qos_action_code),
-  FF_FIELD(BLOCK_ACK_ACTION_CODE                 , block_ack_action_code),
-  FF_FIELD(BLOCK_ACK_PARAM                       , block_ack_param),
-  FF_FIELD(BLOCK_ACK_TIMEOUT                     , block_ack_timeout),
-  FF_FIELD(BLOCK_ACK_SSC                         , block_ack_ssc),
-  FF_FIELD(QOS_TS_INFO                           , qos_ts_info),
-  FF_FIELD(MESH_ACTION                           , mesh_action),
-  FF_FIELD(MULTIHOP_ACTION                       , multihop_action),
-  FF_FIELD(MESH_CONTROL                          , mesh_control),
-  FF_FIELD(SELFPROT_ACTION                       , selfprot_action),
-  FF_FIELD(DLS_ACTION_CODE                       , dls_action_code),
-  FF_FIELD(DST_MAC_ADDR                          , dst_mac_addr),
-  FF_FIELD(SRC_MAC_ADDR                          , src_mac_addr),
-  FF_FIELD(DLS_TIMEOUT                           , dls_timeout),
-  FF_FIELD(DELBA_PARAM_SET                       , delba_param_set),
-  FF_FIELD(MAX_REG_PWR                           , max_reg_pwr),
-  FF_FIELD(MEASUREMENT_PILOT_INT                 , measurement_pilot_int),
-  FF_FIELD(COUNTRY_STR                           , country_str),
-  FF_FIELD(MAX_TX_PWR                            , max_tx_pwr),
-  FF_FIELD(TX_PWR_USED                           , tx_pwr_used),
-  FF_FIELD(TRANSCEIVER_NOISE_FLOOR               , transceiver_noise_floor),
-  FF_FIELD(CHANNEL_WIDTH                         , channel_width),
-  FF_FIELD(QOS_INFO_AP                           , qos_info_ap),
-  FF_FIELD(QOS_INFO_STA                          , qos_info_sta),
-  FF_FIELD(SM_PWR_CNTRL                          , sm_pwr_cntrl),
-  FF_FIELD(PCO_PHASE_CNTRL                       , pco_phase_cntrl),
-  FF_FIELD(PSMP_PARAM_SET                        , psmp_param_set),
-  FF_FIELD(MIMO_CNTRL                            , mimo_cntrl),
-  FF_FIELD(ANT_SELECTION                         , ant_selection),
-  FF_FIELD(EXTENDED_CHANNEL_SWITCH_ANNOUNCEMENT  , extended_channel_switch_announcement) ,
-  FF_FIELD(HT_INFORMATION                        , ht_information),
-  FF_FIELD(HT_ACTION_CODE                        , ht_action_code),
-  FF_FIELD(PSMP_STA_INFO                         , psmp_sta_info),
-  FF_FIELD(SCHEDULE_INFO                         , schedule_info),
-  FF_FIELD(PA_ACTION_CODE                        , pa_action_code),
-  FF_FIELD(PPA_ACTION_CODE                       , ppa_action_code),
-  FF_FIELD(ACTION                                , action),
-  FF_FIELD(FT_ACTION_CODE                        , ft_action_code),
-  FF_FIELD(STA_ADDRESS                           , sta_address),
-  FF_FIELD(TARGET_AP_ADDRESS                     , target_ap_address),
-  FF_FIELD(GAS_COMEBACK_DELAY                    , gas_comeback_delay),
-  FF_FIELD(GAS_FRAGMENT_ID                       , gas_fragment_id),
-  FF_FIELD(SA_QUERY_ACTION_CODE                  , sa_query_action_code),
-  FF_FIELD(TRANSACTION_ID                        , transaction_id),
-  FF_FIELD(TDLS_ACTION_CODE                      , tdls_action_code),
-  FF_FIELD(TARGET_CHANNEL                        , target_channel),
-  FF_FIELD(OPERATING_CLASS                       , operating_class),
-  FF_FIELD(WNM_ACTION_CODE                       , wnm_action_code),
-  FF_FIELD(UNPROTECTED_WNM_ACTION_CODE           , unprotected_wnm_action_code),
-  FF_FIELD(KEY_DATA_LENGTH                       , key_data_length),
-  FF_FIELD(WNM_NOTIFICATION_TYPE                 , wnm_notification_type),
-  FF_FIELD(RM_ACTION_CODE                        , rm_action_code),
-  FF_FIELD(RM_DIALOG_TOKEN                       , rm_dialog_token),
-  FF_FIELD(RM_REPETITIONS                        , rm_repetitions),
-  FF_FIELD(RM_TX_POWER                           , rm_tx_power),
-  FF_FIELD(RM_MAX_TX_POWER                       , rm_max_tx_power),
-  FF_FIELD(RM_TPC_REPORT                         , rm_tpc_report),
-  FF_FIELD(RM_RX_ANTENNA_ID                      , rm_rx_antenna_id),
-  FF_FIELD(RM_TX_ANTENNA_ID                      , rm_tx_antenna_id),
-  FF_FIELD(RM_RCPI                               , rm_rcpi),
-  FF_FIELD(RM_RSNI                               , rm_rsni),
-  FF_FIELD(RELAY_CAPABLE_STA_INFO                , relay_capable_sta_info),
-  FF_FIELD(BAND_ID                               , band_id),
-  FF_FIELD(DMG_PARAMETERS                        , dmg_params),
-  FF_FIELD(SECTOR_SWEEP                          , sector_sweep),
-  FF_FIELD(DYNAMIC_ALLOCATION                    , dynamic_allocation),
-  FF_FIELD(SECTOR_SWEEP_FB                       , sector_sweep_feedback),
-  FF_FIELD(BRP_REQ                               , BRP_request),
-  FF_FIELD(BEAMFORMED_LINK_MAINTAINCE            , beamformed_link),
-  FF_FIELD(BEAMFORMING_CTRL                      , beamforming_ctrl),
-  FF_FIELD(BEACON_INTERVAL_CTRL                  , beacon_interval_ctrl),
-  FF_FIELD(DMG_ACTION_CODE                       , dmg_action_code),
-  FF_FIELD(DMG_PWR_MGMT                          , dmg_pwr_mgmt),
-  FF_FIELD(REQ_AP_ADDR                           , req_ap_addr),
-  FF_FIELD(RES_AP_ADDR                           , res_ap_addr),
-  FF_FIELD(CHECK_BEACON                          , check_beacon),
-  FF_FIELD(TOD                                   , tod),
-  FF_FIELD(TOA                                   , toa),
-  FF_FIELD(MAX_TOD_ERR                           , max_tod_err),
-  FF_FIELD(MAX_TOA_ERR                           , max_toa_err),
-  FF_FIELD(SUBJECT_ADDRESS                       , subject_address),
-  FF_FIELD(HANDOVER_REASON                       , handover_reason),
-  FF_FIELD(HANDOVER_REMAINING_BI                 , handover_remaining_bi),
-  FF_FIELD(HANDOVER_RESULT                       , handover_result),
-  FF_FIELD(HANDOVER_REJECT_REASON                , handover_reject_reason),
-  FF_FIELD(DESTINATION_REDS_AID                  , destination_reds_aid),
-  FF_FIELD(DESTINATION_AID                       , destination_aid),
-  FF_FIELD(REALY_AID                             , realy_aid),
-  FF_FIELD(SOURCE_AID                            , source_aid),
-  FF_FIELD(TIMING_OFFSET                         , timing_offset),
-  FF_FIELD(SAMPLING_FREQUENCY_OFFSET             , sampling_frequency_offset),
-  FF_FIELD(RELAY_OPERATION_TYPE                  , relay_operation_type),
-  FF_FIELD(UNPROTECTED_DMG_ACTION_CODE           , unprotected_dmg_action_code),
-  FF_FIELD(FST_ACTION_CODE                       , fst_action_code),
-  FF_FIELD(LLT                                   , llt),
-  FF_FIELD(FSTS_ID                               , fsts_id),
-  FF_FIELD(OCT_MMPDU                             , oct_mmpdu),
-  FF_FIELD(VHT_ACTION                            , vht_action),
-  FF_FIELD(BSS_TERMINATION_DELAY                 , bss_termination_delay),
-  FF_FIELD(BSS_TRANSITION_STATUS_CODE            , bss_transition_status_code),
-  { (enum fixed_field)-1                         , NULL }
-};
-
-#undef FF_FIELD
-
-static guint
-add_fixed_field(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset,
-                enum fixed_field lfcode)
-{
-  int i;
-  for (i = 0; ff_dissectors[i].dissector; i++) {
-    if (ff_dissectors[i].lfcode == lfcode) {
-      return ff_dissectors[i].dissector(tree, tvb, pinfo, offset);
-    }
-  }
-  return 0;
-}
-
 static const value_string ieee80211_rsn_cipher_vals[] = {
   {0, "NONE"},
   {1, "WEP (40-bit)"},
@@ -10760,7 +10489,7 @@ dissect_qos_capability(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int
     case MGT_REASSOC_REQ:
     {
       /* To AP so decode Qos Info as STA */
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_QOS_INFO_STA);
+      offset += add_ff_qos_info_sta(tree, tvb, pinfo, offset);
       break;
     }
 
@@ -10770,7 +10499,7 @@ dissect_qos_capability(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int
     case MGT_REASSOC_RESP:
     {
       /* From AP so decode QoS Info as AP */
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_QOS_INFO_AP);
+      offset += add_ff_qos_info_ap(tree, tvb, pinfo, offset);
       break;
     }
 
@@ -14147,7 +13876,7 @@ add_tagged_field(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset
 
 #if 0 /* ToDo */
   case TAG_EDCA_PARAM_SET: /* 8.4.2.31 in 802-11-2012 */
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_QOS_INFO_AP);
+    offset += add_ff_qos_info_ap(tree, tvb, pinfo, offset);
     offset += 1;  /* reserved */
     offset += 4;  /* AC_BE */
     offset += 4;  /* AC_BK */
@@ -14169,7 +13898,7 @@ add_tagged_field(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset
       }
       offset += 2;
 
-      add_fixed_field(tree, tvb, pinfo, offset, FIELD_QOS_TS_INFO);
+      add_ff_qos_ts_info(tree, tvb, pinfo, offset);
       offset += 3;
 
       proto_tree_add_item(tree, hf_ieee80211_tspec_nor_msdu, tvb, offset, 2, ENC_LITTLE_ENDIAN);
@@ -14369,7 +14098,7 @@ add_tagged_field(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset
       }
       offset += 2;
 
-      add_fixed_field(tree, tvb, pinfo, offset, FIELD_SCHEDULE_INFO);
+      add_ff_schedule_info(tree, tvb, pinfo, offset);
       offset += 2;
 
       proto_tree_add_item(tree, hf_ieee80211_sched_srv_start, tvb, offset, 4, ENC_LITTLE_ENDIAN);
@@ -15006,9 +14735,9 @@ add_tagged_field(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset
 
                     rep_tree = proto_tree_add_subtree(sub_tree, tvb, offset, sub_length, ett_tag_measure_reported_frame_tree, NULL, "Reported Frame Body");
 
-                    add_fixed_field(rep_tree, tvb, pinfo, 0, FIELD_TIMESTAMP);
-                    add_fixed_field(rep_tree, tvb, pinfo, 8, FIELD_BEACON_INTERVAL);
-                    add_fixed_field(rep_tree, tvb, pinfo, 10, FIELD_CAP_INFO);
+                    add_ff_timestamp(rep_tree, tvb, pinfo, 0);
+                    add_ff_beacon_interval(rep_tree, tvb, pinfo, 8);
+                    add_ff_cap_info(rep_tree, tvb, pinfo, 10);
                     offset += 12;
 
                     ieee_80211_add_tagged_parameters (tvb, offset, pinfo, rep_tree, sub_length - 12, MGT_PROBE_RESP);
@@ -15483,7 +15212,7 @@ add_tagged_field(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset
                 proto_tree_add_item (tree, hf_ieee80211_mesh_peering_peer_link_id, tvb, offset, 2, ENC_LITTLE_ENDIAN);
                 offset += 2;
               }
-            offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_REASON_CODE);
+            offset += add_ff_reason_code(tree, tvb, pinfo, offset);
             break;
 
           /* unexpected values */
@@ -15640,7 +15369,7 @@ add_tagged_field(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset
             proto_tree_add_item (tree, hf_ieee80211_ff_hwmp_targ_ext, tvb, offset, 6, ENC_NA);
             offset += 6;
           }
-          offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_REASON_CODE);
+          offset += add_ff_reason_code(tree, tvb, pinfo, offset);
         }
         break;
       }
@@ -15725,7 +15454,7 @@ add_tagged_field(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset
 
       offset += 2;
 
-      offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_EXTENDED_CHANNEL_SWITCH_ANNOUNCEMENT);
+      offset += add_ff_extended_channel_switch_announcement(tree, tvb, pinfo, offset);
 
       break;
     }
@@ -15905,7 +15634,7 @@ add_tagged_field(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset
         proto_tree_add_item(alloc_tree, hf_ieee80211_tag_pcp_active, tvb, offset, 2, ENC_LITTLE_ENDIAN);
         proto_tree_add_item(alloc_tree, hf_ieee80211_tag_lp_sc_used, tvb, offset, 2, ENC_LITTLE_ENDIAN);
         offset += 2;
-        offset += add_fixed_field(alloc_tree, tvb, pinfo, offset, FIELD_BEAMFORMING_CTRL);
+        offset += add_ff_beamforming_ctrl(alloc_tree, tvb, pinfo, offset);
         proto_tree_add_item(alloc_tree, hf_ieee80211_tag_src_aid, tvb, offset, 1, ENC_NA);
         offset += 1;
         proto_tree_add_item(alloc_tree, hf_ieee80211_tag_dest_aid, tvb, offset, 1, ENC_NA);
@@ -16115,7 +15844,7 @@ add_tagged_field(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset
       offset += 3;
       isGrant = ((ftype==CTRL_GRANT)||(ftype==CTRL_GRANT_ACK));
       p_add_proto_data(wmem_file_scope(), pinfo, proto_wlan, IS_CTRL_GRANT_OR_GRANT_ACK_KEY, &isGrant);
-      offset += add_fixed_field(tree, tvb, pinfo, 2, FIELD_BEAMFORMING_CTRL);
+      offset += add_ff_beamforming_ctrl(tree, tvb, pinfo, 2);
       proto_tree_add_item(tree, hf_ieee80211_tag_tspec_allocation_period, tvb, offset, 2, ENC_LITTLE_ENDIAN);
       offset += 2;
       proto_tree_add_item(tree, hf_ieee80211_tag_tspec_min_allocation, tvb, offset, 2, ENC_LITTLE_ENDIAN);
@@ -16205,14 +15934,14 @@ add_tagged_field(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset
       proto_tree_add_item(tree, hf_ieee80211_tag_multi_band_ctrl_addr_present, tvb, offset, 1, ENC_NA);
       proto_tree_add_item(tree, hf_ieee80211_tag_multi_band_ctrl_cipher_present, tvb, offset, 1, ENC_NA);
       offset += 1;
-      offset += add_fixed_field(tree, tvb, pinfo, 1, FIELD_BAND_ID);
+      offset += add_ff_band_id(tree, tvb, pinfo, 1);
       proto_tree_add_item(tree, hf_ieee80211_tag_multi_band_oper_class, tvb, offset, 1, ENC_NA);
       offset += 1;
       proto_tree_add_item(tree, hf_ieee80211_tag_multi_band_channel_number, tvb, offset, 1, ENC_NA);
       offset += 1;
       proto_tree_add_item(tree, hf_ieee80211_tag_bssid, tvb, offset, 6, ENC_NA);
       offset += 6;
-      offset += add_fixed_field(tree, tvb, pinfo, 2, FIELD_BEACON_INTERVAL);
+      offset += add_ff_beacon_interval(tree, tvb, pinfo, 2);
       proto_tree_add_item(tree, hf_ieee80211_tag_multi_band_tsf_offset, tvb, offset, 8, ENC_LITTLE_ENDIAN);
       offset += 8;
       proto_tree_add_item(tree, hf_ieee80211_tag_multi_band_conn_ap, tvb, offset, 1, ENC_NA);
@@ -16309,8 +16038,8 @@ add_tagged_field(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset
         break;
       }
       offset += 2;
-      offset += add_fixed_field(tree, tvb, pinfo, 1, FIELD_BAND_ID);
-      offset += add_fixed_field(tree, tvb, pinfo, 1, FIELD_BAND_ID);
+      offset += add_ff_band_id(tree, tvb, pinfo, 1);
+      offset += add_ff_band_id(tree, tvb, pinfo, 1);
       proto_tree_add_item(tree, hf_ieee80211_tag_switching_stream_non_qos, tvb, offset, 1, ENC_NA);
       offset += 1;
       param_num = tvb_get_letohs(tvb, offset);
@@ -16395,8 +16124,8 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
 
     case MGT_ASSOC_REQ:
       fixed_tree = get_fixed_parameter_tree (mgt_tree, tvb, 0, 4);
-      add_fixed_field(fixed_tree, tvb, pinfo, 0, FIELD_CAP_INFO);
-      add_fixed_field(fixed_tree, tvb, pinfo, 2, FIELD_LISTEN_IVAL);
+      add_ff_cap_info(fixed_tree, tvb, pinfo, 0);
+      add_ff_listen_ival(fixed_tree, tvb, pinfo, 2);
       offset = 4;  /* Size of fixed fields */
 
       tagged_parameter_tree_len =
@@ -16410,9 +16139,9 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
 
     case MGT_ASSOC_RESP:
       fixed_tree = get_fixed_parameter_tree (mgt_tree, tvb, 0, 6);
-      add_fixed_field(fixed_tree, tvb, pinfo, 0, FIELD_CAP_INFO);
-      add_fixed_field(fixed_tree, tvb, pinfo, 2, FIELD_STATUS_CODE);
-      add_fixed_field(fixed_tree, tvb, pinfo, 4, FIELD_ASSOC_ID);
+      add_ff_cap_info(fixed_tree, tvb, pinfo, 0);
+      add_ff_status_code(fixed_tree, tvb, pinfo, 2);
+      add_ff_assoc_id(fixed_tree, tvb, pinfo, 4);
       offset = 6;  /* Size of fixed fields */
 
       tagged_parameter_tree_len =
@@ -16426,9 +16155,9 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
 
     case MGT_REASSOC_REQ:
       fixed_tree = get_fixed_parameter_tree (mgt_tree, tvb, 0, 10);
-      add_fixed_field(fixed_tree, tvb, pinfo, 0, FIELD_CAP_INFO);
-      add_fixed_field(fixed_tree, tvb, pinfo, 2, FIELD_LISTEN_IVAL);
-      add_fixed_field(fixed_tree, tvb, pinfo, 4, FIELD_CURRENT_AP_ADDR);
+      add_ff_cap_info(fixed_tree, tvb, pinfo, 0);
+      add_ff_listen_ival(fixed_tree, tvb, pinfo, 2);
+      add_ff_current_ap_addr(fixed_tree, tvb, pinfo, 4);
       offset = 10;  /* Size of fixed fields */
 
       tagged_parameter_tree_len =
@@ -16441,9 +16170,9 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
 
     case MGT_REASSOC_RESP:
       fixed_tree = get_fixed_parameter_tree (mgt_tree, tvb, 0, 6);
-      add_fixed_field(fixed_tree, tvb, pinfo, 0, FIELD_CAP_INFO);
-      add_fixed_field(fixed_tree, tvb, pinfo, 2, FIELD_STATUS_CODE);
-      add_fixed_field(fixed_tree, tvb, pinfo, 4, FIELD_ASSOC_ID);
+      add_ff_cap_info(fixed_tree, tvb, pinfo, 0);
+      add_ff_status_code(fixed_tree, tvb, pinfo, 2);
+      add_ff_assoc_id(fixed_tree, tvb, pinfo, 4);
       offset = 6;  /* Size of fixed fields */
 
       tagged_parameter_tree_len =
@@ -16468,9 +16197,9 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
     case MGT_PROBE_RESP:
     {
       fixed_tree = get_fixed_parameter_tree (mgt_tree, tvb, 0, 12);
-      add_fixed_field(fixed_tree, tvb, pinfo, 0, FIELD_TIMESTAMP);
-      add_fixed_field(fixed_tree, tvb, pinfo, 8, FIELD_BEACON_INTERVAL);
-      add_fixed_field(fixed_tree, tvb, pinfo, 10, FIELD_CAP_INFO);
+      add_ff_timestamp(fixed_tree, tvb, pinfo, 0);
+      add_ff_beacon_interval(fixed_tree, tvb, pinfo, 8);
+      add_ff_cap_info(fixed_tree, tvb, pinfo, 10);
       offset = 12;  /* Size of fixed fields */
 
       tagged_parameter_tree_len = tvb_reported_length_remaining(tvb, offset);
@@ -16481,15 +16210,15 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
     case MGT_MEASUREMENT_PILOT:
     {
       fixed_tree = get_fixed_parameter_tree (mgt_tree, tvb, 0, 12);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_TIMESTAMP);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_MEASUREMENT_PILOT_INT);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_BEACON_INTERVAL);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_CAP_INFO);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_COUNTRY_STR);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_MAX_REG_PWR);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_MAX_TX_PWR);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_TX_PWR_USED);
-      offset += add_fixed_field(fixed_tree, tvb, pinfo, offset, FIELD_TRANSCEIVER_NOISE_FLOOR);
+      offset += add_ff_timestamp(fixed_tree, tvb, pinfo, offset);
+      offset += add_ff_measurement_pilot_int(fixed_tree, tvb, pinfo, offset);
+      offset += add_ff_beacon_interval(fixed_tree, tvb, pinfo, offset);
+      offset += add_ff_cap_info(fixed_tree, tvb, pinfo, offset);
+      offset += add_ff_country_str(fixed_tree, tvb, pinfo, offset);
+      offset += add_ff_max_reg_pwr(fixed_tree, tvb, pinfo, offset);
+      offset += add_ff_max_tx_pwr(fixed_tree, tvb, pinfo, offset);
+      offset += add_ff_tx_pwr_used(fixed_tree, tvb, pinfo, offset);
+      offset += add_ff_transceiver_noise_floor(fixed_tree, tvb, pinfo, offset);
       /* TODO DS Parameter Set ??? */
 
       tagged_parameter_tree_len = tvb_reported_length_remaining(tvb, offset);
@@ -16499,9 +16228,9 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
     }
     case MGT_BEACON:    /* Dissect protocol payload fields  */
       fixed_tree = get_fixed_parameter_tree (mgt_tree, tvb, 0, 12);
-      add_fixed_field(fixed_tree, tvb, pinfo, 0, FIELD_TIMESTAMP);
-      add_fixed_field(fixed_tree, tvb, pinfo, 8, FIELD_BEACON_INTERVAL);
-      add_fixed_field(fixed_tree, tvb, pinfo, 10, FIELD_CAP_INFO);
+      add_ff_timestamp(fixed_tree, tvb, pinfo, 0);
+      add_ff_beacon_interval(fixed_tree, tvb, pinfo, 8);
+      add_ff_cap_info(fixed_tree, tvb, pinfo, 10);
       offset = 12;  /* Size of fixed fields */
 
       tagged_parameter_tree_len =
@@ -16517,7 +16246,7 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
 
     case MGT_DISASS:
       fixed_tree = get_fixed_parameter_tree (mgt_tree, tvb, 0, 2);
-      add_fixed_field(fixed_tree, tvb, pinfo, 0, FIELD_REASON_CODE);
+      add_ff_reason_code(fixed_tree, tvb, pinfo, 0);
       offset = 2; /* Size of fixed fields */
       tagged_parameter_tree_len = tvb_reported_length_remaining(tvb, offset);
       if (tagged_parameter_tree_len > 0) {
@@ -16530,9 +16259,9 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
 
     case MGT_AUTHENTICATION:
       fixed_tree = get_fixed_parameter_tree (mgt_tree, tvb, 0, 6);
-      add_fixed_field(fixed_tree, tvb, pinfo, 0, FIELD_AUTH_ALG);
-      add_fixed_field(fixed_tree, tvb, pinfo, 2, FIELD_AUTH_TRANS_SEQ);
-      add_fixed_field(fixed_tree, tvb, pinfo, 4, FIELD_STATUS_CODE);
+      add_ff_auth_alg(fixed_tree, tvb, pinfo, 0);
+      add_ff_auth_trans_seq(fixed_tree, tvb, pinfo, 2);
+      add_ff_status_code(fixed_tree, tvb, pinfo, 4);
       offset = 6;  /* Size of fixed fields */
 
       tagged_parameter_tree_len =
@@ -16550,7 +16279,7 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
 
     case MGT_DEAUTHENTICATION:
       fixed_tree = get_fixed_parameter_tree (mgt_tree, tvb, 0, 2);
-      add_fixed_field(fixed_tree, tvb, pinfo, 0, FIELD_REASON_CODE);
+      add_ff_reason_code(fixed_tree, tvb, pinfo, 0);
       offset = 2; /* Size of fixed fields */
       tagged_parameter_tree_len = tvb_reported_length_remaining(tvb, offset);
       if (tagged_parameter_tree_len > 0) {
@@ -16566,7 +16295,7 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
       proto_item *lcl_fixed_hdr;
       proto_tree *lcl_fixed_tree;
       lcl_fixed_tree = proto_tree_add_subtree(mgt_tree, tvb, 0, 0, ett_fixed_parameters, &lcl_fixed_hdr, "Fixed parameters");
-      offset += add_fixed_field(lcl_fixed_tree, tvb, pinfo, 0, FIELD_ACTION);
+      offset += add_ff_action(lcl_fixed_tree, tvb, pinfo, 0);
 
       proto_item_set_len(lcl_fixed_hdr, offset);
       if (ieee80211_tvb_invalid)
@@ -16587,7 +16316,7 @@ dissect_ieee80211_mgt (guint16 fcf, tvbuff_t *tvb, packet_info *pinfo, proto_tre
       proto_tree *lcl_fixed_tree;
       lcl_fixed_tree = proto_tree_add_subtree(mgt_tree, tvb, 0, 0, ett_fixed_parameters, &lcl_fixed_hdr, "Fixed parameters");
 
-      offset += add_fixed_field(lcl_fixed_tree, tvb, pinfo, 0, FIELD_ACTION);
+      offset += add_ff_action(lcl_fixed_tree, tvb, pinfo, 0);
 
       proto_item_set_len(lcl_fixed_hdr, offset);
       if (ieee80211_tvb_invalid)
@@ -17341,8 +17070,7 @@ dissect_ieee80211_common (tvbuff_t *tvb, packet_info *pinfo,
                 hf_ieee80211_block_ack_control_basic_tid_info, tvb, offset, 2, ENC_LITTLE_ENDIAN);
                 offset += 2;
 
-                /*offset +=*/ add_fixed_field(hdr_tree, tvb, pinfo, offset,
-                  FIELD_BLOCK_ACK_SSC);
+                /*offset +=*/ add_ff_block_ack_ssc(hdr_tree, tvb, pinfo, offset);
                 break;
               }
               case 1: /* Extended Compressesd BlockAckReq */
@@ -17357,8 +17085,7 @@ dissect_ieee80211_common (tvbuff_t *tvb, packet_info *pinfo,
                 hf_ieee80211_block_ack_control_compressed_tid_info, tvb, offset, 2, ENC_LITTLE_ENDIAN);
                 offset += 2;
 
-                /*offset +=*/ add_fixed_field(hdr_tree, tvb, pinfo, offset,
-                  FIELD_BLOCK_ACK_SSC);
+                /*offset +=*/ add_ff_block_ack_ssc(hdr_tree, tvb, pinfo, offset);
                 break;
               }
               case 3: /* Multi-TID BlockAckReq */
@@ -17386,7 +17113,7 @@ dissect_ieee80211_common (tvbuff_t *tvb, packet_info *pinfo,
                   proto_tree_add_item(bar_mtid_sub_tree, hf_ieee80211_block_ack_multi_tid_value, tvb, offset, 2, ENC_LITTLE_ENDIAN);
                   offset += 2;
 
-                  offset += add_fixed_field(bar_mtid_sub_tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_SSC);
+                  offset += add_ff_block_ack_ssc(bar_mtid_sub_tree, tvb, pinfo, offset);
                 }
                 break;
               }
@@ -17440,7 +17167,7 @@ dissect_ieee80211_common (tvbuff_t *tvb, packet_info *pinfo,
                 hf_ieee80211_block_ack_control_basic_tid_info, tvb, offset, 2, ENC_LITTLE_ENDIAN);
                 offset += 2;
 
-                offset += add_fixed_field(hdr_tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_SSC);
+                offset += add_ff_block_ack_ssc(hdr_tree, tvb, pinfo, offset);
                 proto_tree_add_item(hdr_tree, hf_ieee80211_block_ack_bitmap, tvb, offset, 128, ENC_NA);
                 /*offset += 128;*/
                 break;
@@ -17463,7 +17190,7 @@ dissect_ieee80211_common (tvbuff_t *tvb, packet_info *pinfo,
 
                 ssn = tvb_get_letohs(tvb, offset);
                 ssn >>= 4;
-                offset += add_fixed_field(hdr_tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_SSC);
+                offset += add_ff_block_ack_ssc(hdr_tree, tvb, pinfo, offset);
                 bmap = tvb_get_letoh64(tvb, offset);
                 ba_bitmap_item = proto_tree_add_item(hdr_tree, hf_ieee80211_block_ack_bitmap, tvb, offset, 8, ENC_NA);
                 ba_bitmap_tree = proto_item_add_subtree(ba_bitmap_item, ett_block_ack_bitmap);
@@ -17491,7 +17218,7 @@ dissect_ieee80211_common (tvbuff_t *tvb, packet_info *pinfo,
 
                 ssn = tvb_get_letohs(tvb, offset);
                 ssn >>= 4;
-                offset += add_fixed_field(hdr_tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_SSC);
+                offset += add_ff_block_ack_ssc(hdr_tree, tvb, pinfo, offset);
                 bmap = tvb_get_letoh64(tvb, offset);
                 ba_bitmap_item = proto_tree_add_item(hdr_tree, hf_ieee80211_block_ack_bitmap, tvb, offset, 8, ENC_NA);
                 ba_bitmap_tree = proto_item_add_subtree(ba_bitmap_item, ett_block_ack_bitmap);
@@ -17524,7 +17251,7 @@ dissect_ieee80211_common (tvbuff_t *tvb, packet_info *pinfo,
                   proto_tree_add_item(ba_mtid_sub_tree, hf_ieee80211_block_ack_multi_tid_value, tvb, offset, 2, ENC_LITTLE_ENDIAN);
                   offset += 2;
 
-                  offset += add_fixed_field(ba_mtid_sub_tree, tvb, pinfo, offset, FIELD_BLOCK_ACK_SSC);
+                  offset += add_ff_block_ack_ssc(ba_mtid_sub_tree, tvb, pinfo, offset);
                   proto_tree_add_item(ba_mtid_sub_tree, hf_ieee80211_block_ack_bitmap, tvb, offset, 8, ENC_NA);
                   offset += 8;
                 }
@@ -17550,28 +17277,28 @@ dissect_ieee80211_common (tvbuff_t *tvb, packet_info *pinfo,
         case CTRL_SPR: {
           gboolean isGrant;
           if(ctrl_type_subtype != CTRL_GRANT_ACK) {
-            offset += add_fixed_field(hdr_tree, tvb, pinfo, offset, FIELD_DYNAMIC_ALLOCATION);
+            offset += add_ff_dynamic_allocation(hdr_tree, tvb, pinfo, offset);
           } else { /* CTRL_GRANT_ACK have 5 octets that are reserved thus not shown.*/
             offset += 5;
           }
           /* offset += commented to avoid Clang warnings*/
           isGrant = ((ctrl_type_subtype==CTRL_GRANT)||(ctrl_type_subtype==CTRL_GRANT_ACK));
           p_add_proto_data(wmem_file_scope(), pinfo, proto_wlan, IS_CTRL_GRANT_OR_GRANT_ACK_KEY, &isGrant);
-          add_fixed_field(hdr_tree, tvb, pinfo, offset, FIELD_BEAMFORMING_CTRL);
+          add_ff_beamforming_ctrl(hdr_tree, tvb, pinfo, offset);
           break;
         }
         case CTRL_SSW: {
-          offset += add_fixed_field(hdr_tree, tvb, pinfo, offset, FIELD_SECTOR_SWEEP);
+          offset += add_ff_sector_sweep(hdr_tree, tvb, pinfo, offset);
           /* offset += commented to avoid Clang warnings*/
-          add_fixed_field(hdr_tree, tvb, pinfo, offset, FIELD_SECTOR_SWEEP_FB);
+          add_ff_sector_sweep_feedback(hdr_tree, tvb, pinfo, offset);
           break;
         }
         case CTRL_SSW_ACK:
         case CTRL_SSW_FEEDBACK: {
-          offset += add_fixed_field(hdr_tree, tvb, pinfo, offset, FIELD_SECTOR_SWEEP_FB);
-          offset += add_fixed_field(hdr_tree, tvb, pinfo, offset, FIELD_BRP_REQ);
+          offset += add_ff_sector_sweep_feedback(hdr_tree, tvb, pinfo, offset);
+          offset += add_ff_BRP_request(hdr_tree, tvb, pinfo, offset);
           /* offset += commented to avoid Clang warnings*/
-          add_fixed_field(hdr_tree, tvb, pinfo, offset, FIELD_BEAMFORMED_LINK_MAINTAINCE);
+          add_ff_beamformed_link(hdr_tree, tvb, pinfo, offset);
           break;
         }
         case CTRL_DMG_DTS: {
@@ -17974,7 +17701,7 @@ dissect_ieee80211_common (tvbuff_t *tvb, packet_info *pinfo,
 
           msh_fields = proto_tree_add_item(hdr_tree, hf_ieee80211_mesh_control_field, tvb, meshoff, meshctl_len, ENC_NA);
           msh_tree = proto_item_add_subtree (msh_fields, ett_msh_control);
-          add_fixed_field(msh_tree, tvb, pinfo, meshoff, FIELD_MESH_CONTROL);
+          add_ff_mesh_control(msh_tree, tvb, pinfo, meshoff);
         }
 
       } /* end of qos control field */
@@ -19143,7 +18870,7 @@ dissect_data_encap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* da
   case 2:
     col_set_str(pinfo->cinfo, COL_PROTOCOL, "TDLS");
     col_clear(pinfo->cinfo, COL_INFO);
-    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_ACTION);
+    offset += add_ff_action(tree, tvb, pinfo, offset);
     tagged_parameter_tree_len = tvb_reported_length_remaining(tvb, offset);
     if (tagged_parameter_tree_len > 0) {
       tagged_tree = get_tagged_parameter_tree(tree, tvb, offset,