From Peter Wu via https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=9373

ieee80211: Decode Radio Measurements (Action Frames)

The length of the fixed fields are dependent on the radio measurement
action. Before this patch, fields following the action code were
ignored, leading to wrong decoding results. This patch adds recognition
for the Radio Measurement action management frames as specified in
IEEE Std 802.11-2012.

From me:
* Rename some hf (Add ff_ in name)
* Link Margin and Transmit Power are signed
* Use always proto_tree_add_item (replace proto_tree_add_text)

svn path=/trunk/; revision=53074

1 files changed, 269 insertions, 0 deletions

diff --git a/epan/dissectors/packet-ieee80211.c b/epan/dissectors/packet-ieee80211.c
index a4de6d4c4e..bcb41ee993 100644
--- a/epan/dissectors/packet-ieee80211.c
+++ b/epan/dissectors/packet-ieee80211.c
@@ -528,6 +528,16 @@ enum fixed_field {
   FIELD_WNM_ACTION_CODE,
   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,
                                               /* add any new fixed field value above this line */
   MAX_FIELD_NUM
 };
@@ -1237,6 +1247,14 @@ static value_string_ext aruba_mgt_typevals_ext = VALUE_STRING_EXT_INIT(aruba_mgt
 #define TDLS_PEER_TRAFFIC_RESPONSE      9
 #define TDLS_DISCOVERY_REQUEST          10
 
+/* IEEE Std 802.11-2012, 8.5.7.1, Table 8-206 */
+#define RM_ACTION_RADIO_MEASUREMENT_REQUEST         0
+#define RM_ACTION_RADIO_MEASUREMENT_REPORT          1
+#define RM_ACTION_LINK_MEASUREMENT_REQUEST          2
+#define RM_ACTION_LINK_MEASUREMENT_REPORT           3
+#define RM_ACTION_NEIGHBOR_REPORT_REQUEST           4
+#define RM_ACTION_NEIGHBOR_REPORT_RESPONSE          5
+
 /* 11s draft 12.0, table 7-57v30 */
 #define MESH_ACTION_LINK_METRIC_REPORT              0
 #define MESH_ACTION_HWMP                            1
@@ -2815,6 +2833,20 @@ static int hf_ieee80211_ff_wnm_action_code = -1;
 static int hf_ieee80211_ff_key_data_length = -1;
 static int hf_ieee80211_ff_key_data = -1;
 static int hf_ieee80211_ff_wnm_notification_type = -1;
+static int hf_ieee80211_ff_rm_action_code = -1;
+static int hf_ieee80211_ff_rm_dialog_token = -1;
+static int hf_ieee80211_ff_rm_repetitions = -1;
+static int hf_ieee80211_ff_rm_tx_power = -1;
+static int hf_ieee80211_ff_rm_max_tx_power = -1;
+static int hf_ieee80211_ff_tpc = -1;
+static int hf_ieee80211_ff_tpc_element_id = -1;
+static int hf_ieee80211_ff_tpc_length = -1;
+static int hf_ieee80211_ff_tpc_tx_power = -1;
+static int hf_ieee80211_ff_tpc_link_margin = -1;
+static int hf_ieee80211_ff_rm_rx_antenna_id = -1;
+static int hf_ieee80211_ff_rm_tx_antenna_id = -1;
+static int hf_ieee80211_ff_rm_rcpi = -1;
+static int hf_ieee80211_ff_rm_rsni = -1;
 static int hf_ieee80211_ff_request_mode_pref_cand = -1;
 static int hf_ieee80211_ff_request_mode_abridged = -1;
 static int hf_ieee80211_ff_request_mode_disassoc_imminent = -1;
@@ -4264,6 +4296,8 @@ static gint ett_ff_chan_switch_announce = -1;
 static gint ett_ff_ht_info = -1;
 static gint ett_ff_psmp_sta_info = -1;
 
+static gint ett_tpc = -1;
+
 static gint ett_msdu_aggregation_parent_tree = -1;
 static gint ett_msdu_aggregation_subframe_tree = -1;
 
@@ -4398,6 +4432,17 @@ static const value_string tdls_action_codes[] = {
 };
 static value_string_ext tdls_action_codes_ext = VALUE_STRING_EXT_INIT(tdls_action_codes);
 
+static const value_string rm_action_codes[] = {
+  {RM_ACTION_RADIO_MEASUREMENT_REQUEST,   "Radio Measurement Request"},
+  {RM_ACTION_RADIO_MEASUREMENT_REPORT,    "Radio Measurement Report"},
+  {RM_ACTION_LINK_MEASUREMENT_REQUEST,    "Link Measurement Request"},
+  {RM_ACTION_LINK_MEASUREMENT_REPORT,     "Link Measurement Report"},
+  {RM_ACTION_NEIGHBOR_REPORT_REQUEST,     "Neighbor Report Request"},
+  {RM_ACTION_NEIGHBOR_REPORT_RESPONSE,    "Neighbor Report Response"},
+  {0, NULL}
+};
+static value_string_ext rm_action_codes_ext = VALUE_STRING_EXT_INIT(rm_action_codes);
+
 AIRPDCAP_CONTEXT airpdcap_ctx;
 
 #define PSMP_STA_INFO_BROADCAST 0
@@ -6868,6 +6913,54 @@ add_ff_action_public(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int of
 }
 
 static guint
+add_ff_action_radio_measurement(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
+{
+  guint  start = offset;
+  guint8 code;
+
+  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_CATEGORY_CODE);
+  code = tvb_get_guint8(tvb, offset);
+  offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_ACTION_CODE);
+
+  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);
+    /* Followed by Measurement Request Elements */
+    break;
+  case RM_ACTION_RADIO_MEASUREMENT_REPORT:
+    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_DIALOG_TOKEN);
+    /* 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);
+    /* 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);
+    /* Followed by Optional Subelements */
+    break;
+  case RM_ACTION_NEIGHBOR_REPORT_REQUEST:
+    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_DIALOG_TOKEN);
+    /* Followed by Optional Subelements */
+    break;
+  case RM_ACTION_NEIGHBOR_REPORT_RESPONSE:
+    offset += add_fixed_field(tree, tvb, pinfo, offset, FIELD_RM_DIALOG_TOKEN);
+    /* Followed by Neighbor Report Elements */
+    break;
+  }
+
+  return offset - start;  /* Size of fixed fields */
+}
+
+static guint
 add_ff_action_fast_bss_transition(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
 {
   guint  start = offset;
@@ -7303,6 +7396,8 @@ add_ff_action(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, int offset)
     return add_ff_action_block_ack(tree, tvb, pinfo, offset);
   case CAT_PUBLIC:
     return add_ff_action_public(tree, tvb, pinfo, offset);
+  case CAT_RADIO_MEASUREMENT:
+    return add_ff_action_radio_measurement(tree, tvb, pinfo, offset);
   case CAT_FAST_BSS_TRANSITION:
     return add_ff_action_fast_bss_transition(tree, tvb, pinfo, offset);
   case CAT_SA_QUERY:
@@ -7449,6 +7544,98 @@ add_ff_wnm_notification_type(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo
   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;
+}
+
 #define FF_FIELD(f, func) { FIELD_ ## f, add_ff_ ## func }
 
 static const struct ieee80211_fixed_field_dissector ff_dissectors[] = {
@@ -7516,6 +7703,17 @@ static const struct ieee80211_fixed_field_dissector ff_dissectors[] = {
   FF_FIELD(WNM_ACTION_CODE                       , 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),
+
   { (enum fixed_field)-1                         , NULL }
 };
 
@@ -15851,6 +16049,76 @@ proto_register_ieee80211 (void)
       FT_UINT8, BASE_DEC|BASE_EXT_STRING, &wnm_notification_types_ext, 0,
       NULL, HFILL }},
 
+    {&hf_ieee80211_ff_rm_action_code,
+     {"Action code", "wlan_mgt.rm.action_code",
+      FT_UINT8, BASE_DEC|BASE_EXT_STRING, &rm_action_codes_ext, 0,
+      "Radio Measurement Action", HFILL }},
+
+    {&hf_ieee80211_ff_rm_dialog_token,
+     {"Dialog token", "wlan_mgt.rm.dialog_token",
+      FT_UINT8, BASE_DEC, NULL, 0,
+      "Non-zero Dialog Token identifies request/report transaction", HFILL }},
+
+    {&hf_ieee80211_ff_rm_repetitions,
+     {"Repetitions", "wlan_mgt.rm.repetitions",
+      FT_UINT16, BASE_DEC, NULL, 0,
+      "Numer of Repetitions, 65535 indicates repeat until cancellation", HFILL }},
+
+    {&hf_ieee80211_ff_rm_tx_power,
+     {"Transmit Power Used", "wlan_mgt.rm.tx_power",
+      FT_INT8, BASE_DEC, NULL, 0,
+      NULL, HFILL }},
+
+    {&hf_ieee80211_ff_rm_max_tx_power,
+     {"Max Transmit Power", "wlan_mgt.rm.max_tx_power",
+      FT_INT8, BASE_DEC, NULL, 0,
+      NULL, HFILL }},
+
+    {&hf_ieee80211_ff_tpc,
+     {"TPC Report", "wlan_mgt.rm.tpc",
+      FT_NONE, BASE_NONE, NULL, 0,
+      NULL, HFILL }},
+
+    {&hf_ieee80211_ff_tpc_element_id,
+     {"TPC Element ID", "wlan_mgt.rm.tpc.element_id",
+      FT_UINT8, BASE_DEC, NULL, 0,
+      NULL, HFILL }},
+
+    {&hf_ieee80211_ff_tpc_length,
+     {"TPC Length", "wlan_mgt.rm.tpc.length",
+      FT_UINT8, BASE_DEC, NULL, 0,
+      "Length of TPC Report element (always 2)", HFILL }},
+
+    {&hf_ieee80211_ff_tpc_tx_power,
+     {"TPC Transmit Power", "wlan_mgt.rm.tpc.tx_power",
+      FT_INT8, BASE_DEC, NULL, 0,
+      NULL, HFILL }},
+
+    {&hf_ieee80211_ff_tpc_link_margin,
+     {"TPC Link Margin", "wlan_mgt.rm.tpc.link_margin",
+      FT_INT8, BASE_DEC, NULL, 0,
+      NULL, HFILL }},
+
+    {&hf_ieee80211_ff_rm_rx_antenna_id,
+     {"Receive Antenna ID", "wlan_mgt.rm.rx_antenna_id",
+      FT_UINT8, BASE_DEC, NULL, 0,
+      NULL, HFILL }},
+
+    {&hf_ieee80211_ff_rm_tx_antenna_id,
+     {"Transmit Antenna ID", "wlan_mgt.rm.tx_antenna_id",
+      FT_UINT8, BASE_DEC, NULL, 0,
+      NULL, HFILL }},
+
+    {&hf_ieee80211_ff_rm_rcpi,
+     {"Received Channel Power", "wlan_mgt.rm.rcpi",
+      FT_UINT8, BASE_DEC, NULL, 0,
+      NULL, HFILL }},
+
+    {&hf_ieee80211_ff_rm_rsni,
+     {"Received Signal to noise indication", "wlan_mgt.rm.rsni",
+      FT_UINT8, BASE_DEC, NULL, 0,
+      NULL, HFILL }},
+
     {&hf_ieee80211_ff_request_mode_pref_cand,
      {"Preferred Candidate List Included","wlan_mgt.fixed.request_mode.pref_cand",
       FT_UINT8, BASE_DEC, NULL, 0x01,
@@ -21425,6 +21693,7 @@ proto_register_ieee80211 (void)
     &ett_wme_ecw,
     &ett_wme_qos_info,
     &ett_ht_cap_tree,
+    &ett_tpc,
     &ett_ath_cap_tree,
     &ett_ff_ba_param_tree,
     &ett_ff_qos_info,