packet-rsl: Fix dissection of "CB Command Type" IE

The "CB Command Type" IE is described in 3GPP TS 48.058 Section 9.3.41,
and consists of three fields.  Prior to this patch, the dissector would
decode none of them and instead produce a non-applicable "channel type"
dissection.

Change-Id: Ibb97432871df1276524fe96512ac1b67d5c5d3f0
Reviewed-on: https://code.wireshark.org/review/29683
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

diff --git a/epan/dissectors/packet-rsl.c b/epan/dissectors/packet-rsl.c
index 98d3267a69883877c9afb622e3a2d2484e74622b..2ab7268c852a19ae621a7e96a277b0943147f5a3 100644 (file)
--- a/epan/dissectors/packet-rsl.c
+++ b/epan/dissectors/packet-rsl.c
@@ -137,6 +137,9 @@ static int hf_rsl_descriptive_group_or_broadcast_call_reference = -1;
 static int hf_rsl_group_channel_description = -1;
 static int hf_rsl_uic = -1;
 static int hf_rsl_codec_list = -1;
+static int hf_rsl_cb_cmd_type = -1;
+static int hf_rsl_cb_def_bcast = -1;
+static int hf_rsl_cb_last_block = -1;
 
 /* Encapsulating paging messages into a packet REF: EP2192796 - proprietor Huawei */
 static int hf_rsl_paging_spare                 = -1;
@@ -710,6 +713,32 @@ static const value_string rsl_phy_con_ie_vals[] = {
 };
 static value_string_ext rsl_phy_con_ie_vals_ext = VALUE_STRING_EXT_INIT(rsl_phy_con_ie_vals);
 
+/* Section 9.3.41 CB Command Type; bits 5 to 8 */
+static const value_string rsl_cb_cmd_type_vals[] = {
+    { 0x0, "Normal Message Broadcast" },
+    { 0x8, "Schedule Message Broadcast" },
+    { 0xE, "Default Message Broadcast" },
+    { 0xF, "Null Message Broadcast" },
+    { 0, NULL }
+};
+
+/* Section 9.3.41 CB Command Type; bit 4 */
+static const value_string rsl_cb_cmd_type_def_bcast_vals[] = {
+    { 0x0, "Normal Message" },
+    { 0x1, "Null Message" },
+    { 0, NULL }
+};
+
+/* Section 9.3.41 CB Command Type; bits 1 and 2 */
+static const value_string rsl_cb_cmd_type_last_block_vals[] = {
+    { 0x0, "Block 4/4" },
+    { 0x1, "Block 1/4" },
+    { 0x2, "Block 2/4" },
+    { 0x3, "Block 3/4" },
+    { 0, NULL }
+};
+
+
 /* From openbsc/include/openbsc/tlv.h */
 enum tlv_type {
     TLV_TYPE_UNKNOWN,
@@ -2486,8 +2515,9 @@ dissect_rsl_ie_cb_cmd_type(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tr
     proto_tree_add_item(ie_tree, hf_rsl_ie_id, tvb, offset, 1, ENC_BIG_ENDIAN);
     offset++;
 
-    /* Channel */
-    proto_tree_add_item(ie_tree, hf_rsl_ch_needed, tvb, offset, 1, ENC_BIG_ENDIAN);
+    proto_tree_add_item(ie_tree, hf_rsl_cb_cmd_type, tvb, offset, 1, ENC_NA);
+    proto_tree_add_item(ie_tree, hf_rsl_cb_def_bcast, tvb, offset, 1, ENC_NA);
+    proto_tree_add_item(ie_tree, hf_rsl_cb_last_block, tvb, offset, 1, ENC_NA);
     offset++;
 
     return offset;
@@ -4728,6 +4758,21 @@ void proto_register_rsl(void)
             FT_UINT8, BASE_HEX_DEC, NULL, 0xff,
             NULL, HFILL }
         },
+        { &hf_rsl_cb_cmd_type,
+          { "CB Command", "gsm_abis_rsl.cb_cmd_type.command",
+            FT_UINT8, BASE_HEX, VALS(rsl_cb_cmd_type_vals), 0xf0,
+            NULL, HFILL }
+        },
+        { &hf_rsl_cb_def_bcast,
+          { "CB Default Broadcast", "gsm_abis_rsl.cb_cmd_type.def_bcast",
+            FT_UINT8, BASE_HEX, VALS(rsl_cb_cmd_type_def_bcast_vals), 0x08,
+            NULL, HFILL }
+        },
+        { &hf_rsl_cb_last_block,
+          { "CB Last Block", "gsm_abis_rsl.cb_cmd_type.last_block",
+            FT_UINT8, BASE_HEX, VALS(rsl_cb_cmd_type_last_block_vals), 0x03,
+            NULL, HFILL }
+        },
       /* Generated from convert_proto_tree_add_text.pl */
       { &hf_rsl_channel_description_tag, { "Channel Description Tag", "gsm_abis_rsl.channel_description_tag", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }},
       { &hf_rsl_mobile_allocation_tag, { "Mobile Allocation Tag+Length(0)", "gsm_abis_rsl.mobile_allocation_tag", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }},