USB Audio: Add dissection of Format Type Descriptor

Only support Type 1 and 2

Change-Id: I0d2f5b9bc59063cb77d81667fe68c37133985568
Ping-Bug:11858
Reviewed-on: https://code.wireshark.org/review/15039
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 123 insertions, 0 deletions

diff --git a/epan/dissectors/packet-usb-audio.c b/epan/dissectors/packet-usb-audio.c
index bce611f889..242d6c0290 100644
--- a/epan/dissectors/packet-usb-audio.c
+++ b/epan/dissectors/packet-usb-audio.c
@@ -50,6 +50,16 @@ static int hf_as_if_desc_subtype = -1;
 static int hf_as_if_gen_term_id = -1;
 static int hf_as_if_gen_delay = -1;
 static int hf_as_if_gen_format = -1;
+static int hf_as_if_ft_formattype = -1;
+static int hf_as_if_ft_maxbitrate = -1;
+static int hf_as_if_ft_nrchannels = -1;
+static int hf_as_if_ft_subframesize = -1;
+static int hf_as_if_ft_bitresolution = -1;
+static int hf_as_if_ft_samplesperframe = -1;
+static int hf_as_if_ft_samfreqtype = -1;
+static int hf_as_if_ft_lowersamfreq = -1;
+static int hf_as_if_ft_uppersamfreq = -1;
+static int hf_as_if_ft_samfreq = -1;
 static int hf_as_ep_desc_subtype = -1;
 
 static reassembly_table midi_data_reassembly_table;
@@ -380,6 +390,85 @@ dissect_as_if_general_body(tvbuff_t *tvb, gint offset, packet_info *pinfo _U_,
     return offset-offset_start;
 }
 
+static gint
+dissect_as_if_format_type_body(tvbuff_t *tvb, gint offset, packet_info *pinfo _U_,
+        proto_tree *tree, usb_conv_info_t *usb_conv_info)
+{
+    audio_conv_info_t *audio_conv_info;
+    gint               offset_start;
+    guint8 SamFreqType;
+    guint8 format_type;
+
+    /* the caller has already checked that usb_conv_info!=NULL */
+    audio_conv_info = (audio_conv_info_t *)usb_conv_info->class_data;
+    if (!audio_conv_info)
+        return 0;
+
+    offset_start = offset;
+
+    proto_tree_add_item(tree, hf_as_if_ft_formattype, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+    format_type = tvb_get_guint8(tvb, offset);
+    offset++;
+
+
+    switch(format_type){
+        case 1:
+            proto_tree_add_item(tree, hf_as_if_ft_nrchannels, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+            offset += 1;
+
+            proto_tree_add_item(tree, hf_as_if_ft_subframesize, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+            offset += 1;
+
+            proto_tree_add_item(tree, hf_as_if_ft_bitresolution, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+            offset += 1;
+
+            proto_tree_add_item(tree, hf_as_if_ft_samfreqtype, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+            SamFreqType = tvb_get_guint8(tvb, offset);
+            offset++;
+
+            if(SamFreqType == 0){
+                proto_tree_add_item(tree, hf_as_if_ft_lowersamfreq, tvb, offset, 3, ENC_LITTLE_ENDIAN);
+                offset += 3;
+                proto_tree_add_item(tree, hf_as_if_ft_uppersamfreq, tvb, offset, 3, ENC_LITTLE_ENDIAN);
+                offset += 3;
+            }else {
+                while(SamFreqType){
+                    proto_tree_add_item(tree, hf_as_if_ft_samfreq, tvb, offset, 3, ENC_LITTLE_ENDIAN);
+                    offset += 3;
+                    SamFreqType--;
+                }
+            }
+        break;
+        case 2:
+            proto_tree_add_item(tree, hf_as_if_ft_maxbitrate, tvb, offset, 2, ENC_LITTLE_ENDIAN);
+            offset += 2;
+
+            proto_tree_add_item(tree, hf_as_if_ft_samplesperframe, tvb, offset, 2, ENC_LITTLE_ENDIAN);
+            offset += 2;
+
+            proto_tree_add_item(tree, hf_as_if_ft_samfreqtype, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+            SamFreqType = tvb_get_guint8(tvb, offset);
+            offset++;
+
+            if(SamFreqType == 0){
+                proto_tree_add_item(tree, hf_as_if_ft_lowersamfreq, tvb, offset, 3, ENC_LITTLE_ENDIAN);
+                offset += 3;
+                proto_tree_add_item(tree, hf_as_if_ft_uppersamfreq, tvb, offset, 3, ENC_LITTLE_ENDIAN);
+                offset += 3;
+            }else {
+                while(SamFreqType){
+                    proto_tree_add_item(tree, hf_as_if_ft_samfreq, tvb, offset, 3, ENC_LITTLE_ENDIAN);
+                    offset += 3;
+                    SamFreqType--;
+                }
+            }
+        break;
+        default:
+        break;
+    }
+
+    return offset-offset_start;
+}
 
 static gint
 dissect_usb_audio_descriptor(tvbuff_t *tvb, packet_info *pinfo,
@@ -458,6 +547,10 @@ dissect_usb_audio_descriptor(tvbuff_t *tvb, packet_info *pinfo,
                 dissect_as_if_general_body(tvb, offset, pinfo,
                         desc_tree, usb_conv_info);
                 break;
+            case AS_SUBTYPE_FORMAT_TYPE:
+                dissect_as_if_format_type_body(tvb, offset, pinfo,
+                        desc_tree, usb_conv_info);
+                break;
             default:
                 proto_tree_add_expert(desc_tree, pinfo, &ei_usb_audio_undecoded, tvb, offset-3, desc_len);
                 break;
@@ -580,6 +673,36 @@ proto_register_usb_audio(void)
         { &hf_as_if_gen_format,
             { "Format", "usbaudio.as_if_gen.wFormatTag",
               FT_UINT16, BASE_HEX, NULL, 0x00, "wFormatTag", HFILL }},
+        { &hf_as_if_ft_formattype,
+            { "FormatType", "usbaudio.as_if_ft.bFormatType",
+              FT_UINT8, BASE_DEC, NULL, 0x00, "wFormatType", HFILL }},
+        { &hf_as_if_ft_maxbitrate,
+            { "Max Bit Rate", "usbaudio.as_if_ft.wMaxBitRate",
+              FT_UINT16, BASE_DEC, NULL, 0x00, "wMaxBitRate", HFILL }},
+        { &hf_as_if_ft_nrchannels,
+            { "Number Channels", "usbaudio.as_if_ft.bNrChannels",
+              FT_UINT8, BASE_DEC, NULL, 0x00, "bNrChannels", HFILL }},
+        { &hf_as_if_ft_subframesize,
+            { "Subframe Size", "usbaudio.as_if_ft.bSubframeSize",
+              FT_UINT8, BASE_DEC, NULL, 0x00, "bSubframeSize", HFILL }},
+        { &hf_as_if_ft_bitresolution,
+            { "Bit Resolution", "usbaudio.as_if_ft.bBitResolution",
+              FT_UINT8, BASE_DEC, NULL, 0x00, "bBitResolution", HFILL }},
+        { &hf_as_if_ft_samplesperframe,
+            { "Samples Per Frame", "usbaudio.as_if_ft.wSamplesPerFrame",
+              FT_UINT16, BASE_DEC, NULL, 0x00, "wSamplesPerFrame", HFILL }},
+        { &hf_as_if_ft_samfreqtype,
+            { "Samples Frequence Type", "usbaudio.as_if_ft.bSamFreqType",
+              FT_UINT8, BASE_DEC, NULL, 0x00, "bSamFreqType", HFILL }},
+        { &hf_as_if_ft_lowersamfreq,
+            { "Lower Samples Frequence", "usbaudio.as_if_ft.tLowerSamFreq",
+              FT_UINT24, BASE_DEC, NULL, 0x00, "tLowerSamFreq", HFILL }},
+        { &hf_as_if_ft_uppersamfreq,
+            { "Upper Samples Frequence", "usbaudio.as_if_ft.tUpperSamFreq",
+              FT_UINT24, BASE_DEC, NULL, 0x00, "tUpperSamFreq", HFILL }},
+        { &hf_as_if_ft_samfreq,
+            { "Samples Frequence", "usbaudio.as_if_ft.tSamFreq",
+              FT_UINT24, BASE_DEC, NULL, 0x00, "tSamFreq", HFILL }},
         { &hf_as_ep_desc_subtype,
             { "Subtype", "usbaudio.as_ep_subtype", FT_UINT8,
                 BASE_HEX, NULL, 0x00, "bDescriptorSubtype", HFILL }},