epan/dissectors/packet-usb-audio.c

   1 /* packet-usb-audio.c
   2  *
   3  * $Id$
   4  *
   5  * usb audio dissector
   6  * Tomasz Mon 2012
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version 2
  11  * of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #include "config.h"
  24
  25 #include <glib.h>
  26 #include <epan/conversation.h>
  27 #include <epan/expert.h>
  28 #include <epan/packet.h>
  29 #include <epan/reassemble.h>
  30 #include "packet-usb.h"
  31
  32 /* protocols and header fields */
  33 static int proto_usb_audio = -1;
  34 static int hf_midi_cable_number = -1;
  35 static int hf_midi_code_index = -1;
  36 static int hf_midi_event = -1;
  37
  38 static reassembly_table midi_data_reassembly_table;
  39
  40 static gint ett_usb_audio      = -1;
  41 static gint ett_usb_audio_desc = -1;
  42
  43 static dissector_handle_t sysex_handle;
  44
  45 #define AUDIO_SUBCLASS_UNDEFINED        0x00
  46 #define AUDIO_SUBCLASS_AUDIOCONTROL     0x01
  47 #define AUDIO_SUBCLASS_AUDIOSTREAMING   0x02
  48 #define AUDIO_SUBCLASS_MIDISTREAMING    0x03
  49
  50 #if 0
  51 static const value_string usb_audio_subclass_vals[] = {
  52     {AUDIO_SUBCLASS_UNDEFINED,          "SUBCLASS_UNDEFINED"},
  53     {AUDIO_SUBCLASS_AUDIOCONTROL,       "AUDIOCONSTROL"},
  54     {AUDIO_SUBCLASS_AUDIOSTREAMING,     "AUDIOSTREAMING"},
  55     {AUDIO_SUBCLASS_MIDISTREAMING,      "MIDISTREAMING"},
  56     {0, NULL}
  57 };
  58 #endif
  59
  60 static const value_string code_index_vals[] = {
  61     { 0x0, "Miscellaneous (Reserved)" },
  62     { 0x1, "Cable events (Reserved)" },
  63     { 0x2, "Two-byte System Common message" },
  64     { 0x3, "Three-byte System Common message" },
  65     { 0x4, "SysEx starts or continues" },
  66     { 0x5, "SysEx ends with following single byte/Single-byte System Common Message" },
  67     { 0x6, "SysEx ends with following two bytes" },
  68     { 0x7, "SysEx ends with following three bytes" },
  69     { 0x8, "Note-off" },
  70     { 0x9, "Note-on" },
  71     { 0xA, "Poly-KeyPress" },
  72     { 0xB, "Control Change" },
  73     { 0xC, "Program Change" },
  74     { 0xD, "Channel Pressure" },
  75     { 0xE, "PitchBend Change" },
  76     { 0xF, "Single Byte" },
  77     { 0, NULL }
  78 };
  79
  80 /* USB audio specification, section A.8 */
  81 #define CS_INTERFACE       0x24
  82 #define CS_ENDPOINT        0x25
  83
  84 static const value_string aud_descriptor_type_vals[] = {
  85         {CS_INTERFACE, "audio class interface"},
  86         {CS_ENDPOINT, "audio class endpoint"},
  87         {0,NULL}
  88 };
  89 static value_string_ext aud_descriptor_type_vals_ext =
  90     VALUE_STRING_EXT_INIT(aud_descriptor_type_vals);
  91
  92 static int hf_sysex_msg_fragments = -1;
  93 static int hf_sysex_msg_fragment = -1;
  94 static int hf_sysex_msg_fragment_overlap = -1;
  95 static int hf_sysex_msg_fragment_overlap_conflicts = -1;
  96 static int hf_sysex_msg_fragment_multiple_tails = -1;
  97 static int hf_sysex_msg_fragment_too_long_fragment = -1;
  98 static int hf_sysex_msg_fragment_error = -1;
  99 static int hf_sysex_msg_fragment_count = -1;
 100 static int hf_sysex_msg_reassembled_in = -1;
 101 static int hf_sysex_msg_reassembled_length = -1;
 102 static int hf_sysex_msg_reassembled_data = -1;
 103
 104 static gint ett_sysex_msg_fragment = -1;
 105 static gint ett_sysex_msg_fragments = -1;
 106
 107 static expert_field ei_usb_audio_undecoded = EI_INIT;
 108
 109 static const fragment_items sysex_msg_frag_items = {
 110     /* Fragment subtrees */
 111     &ett_sysex_msg_fragment,
 112     &ett_sysex_msg_fragments,
 113     /* Fragment fields */
 114     &hf_sysex_msg_fragments,
 115     &hf_sysex_msg_fragment,
 116     &hf_sysex_msg_fragment_overlap,
 117     &hf_sysex_msg_fragment_overlap_conflicts,
 118     &hf_sysex_msg_fragment_multiple_tails,
 119     &hf_sysex_msg_fragment_too_long_fragment,
 120     &hf_sysex_msg_fragment_error,
 121     &hf_sysex_msg_fragment_count,
 122     /* Reassembled in field */
 123     &hf_sysex_msg_reassembled_in,
 124     /* Reassembled length field */
 125     &hf_sysex_msg_reassembled_length,
 126     &hf_sysex_msg_reassembled_data,
 127     /* Tag */
 128     "Message fragments"
 129 };
 130
 131 static inline gboolean
 132 is_sysex_code(guint8 code)
 133 {
 134     return (code == 0x04 || code == 0x05 || code == 0x06 || code == 0x07);
 135 }
 136
 137 static gboolean
 138 is_last_sysex_packet_in_tvb(tvbuff_t *tvb, gint offset)
 139 {
 140     gboolean last = TRUE;
 141     gint length = tvb_length(tvb);
 142
 143     offset += 4;
 144     while (offset < length)
 145     {
 146         guint8 code = tvb_get_guint8(tvb, offset);
 147         code &= 0x0F;
 148
 149         if (is_sysex_code(code))
 150         {
 151             last = FALSE;
 152             break;
 153         }
 154
 155         offset += 4;
 156     }
 157
 158     return last;
 159 }
 160
 161 static void
 162 dissect_usb_midi_event(tvbuff_t *tvb, packet_info *pinfo,
 163                        proto_tree *usb_audio_tree, proto_tree *parent_tree,
 164                        gint offset)
 165 {
 166     guint8 code;
 167     guint8 cable;
 168     gboolean save_fragmented;
 169     proto_tree *tree = NULL;
 170
 171     col_set_str(pinfo->cinfo, COL_INFO, "USB-MIDI Event Packets");
 172
 173     code = tvb_get_guint8(tvb, offset);
 174     cable = (code & 0xF0) >> 4;
 175     code &= 0x0F;
 176
 177     if (parent_tree)
 178     {
 179         proto_item *ti = NULL;
 180
 181         ti = proto_tree_add_protocol_format(usb_audio_tree, proto_usb_audio, tvb, offset, 4, "USB Midi Event Packet");
 182         tree = proto_item_add_subtree(ti, ett_usb_audio);
 183         proto_tree_add_item(tree, hf_midi_cable_number, tvb, offset, 1, ENC_BIG_ENDIAN);
 184         proto_tree_add_item(tree, hf_midi_code_index, tvb, offset, 1, ENC_BIG_ENDIAN);
 185         proto_tree_add_item(tree, hf_midi_event, tvb, offset+1, 3, ENC_BIG_ENDIAN);
 186     }
 187
 188     save_fragmented = pinfo->fragmented;
 189
 190     /* Reassemble SysEx commands */
 191     if (is_sysex_code(code))
 192     {
 193         tvbuff_t* new_tvb = NULL;
 194         fragment_head *frag_sysex_msg = NULL;
 195
 196         pinfo->fragmented = TRUE;
 197
 198         if (code == 0x04)
 199         {
 200             frag_sysex_msg = fragment_add_seq_next(&midi_data_reassembly_table,
 201                 tvb, offset+1,
 202                 pinfo,
 203                 cable, /* ID for fragments belonging together */
 204                 NULL,
 205                 3,
 206                 TRUE);
 207         }
 208         else
 209         {
 210             frag_sysex_msg = fragment_add_seq_next(&midi_data_reassembly_table,
 211                 tvb, offset+1,
 212                 pinfo,
 213                 cable, /* ID for fragments belonging together */
 214                 NULL,
 215                 (gint)(code - 4),
 216                 FALSE);
 217         }
 218
 219         if (is_last_sysex_packet_in_tvb(tvb, offset))
 220         {
 221             new_tvb = process_reassembled_data(tvb, offset+1, pinfo,
 222                 "Reassembled Message", frag_sysex_msg, &sysex_msg_frag_items,
 223                 NULL, usb_audio_tree);
 224
 225             if (code != 0x04) { /* Reassembled */
 226                 col_append_str(pinfo->cinfo, COL_INFO,
 227                         " (SysEx Reassembled)");
 228             } else { /* Not last packet of reassembled Short Message */
 229                 col_append_str(pinfo->cinfo, COL_INFO,
 230                         " (SysEx fragment)");
 231             }
 232
 233             if (new_tvb)
 234             {
 235                 call_dissector(sysex_handle, new_tvb, pinfo, parent_tree);
 236             }
 237         }
 238     }
 239
 240     pinfo->fragmented = save_fragmented;
 241 }
 242
 243
 244 static gint
 245 dissect_usb_audio_descriptor(tvbuff_t *tvb, packet_info *pinfo _U_,
 246         proto_tree *tree, void *data _U_)
 247 {
 248     gint        offset = 0;
 249     guint8      descriptor_len;
 250     guint8      descriptor_type;
 251     proto_item *item = NULL;
 252     proto_tree *desc_tree;
 253
 254     descriptor_len  = tvb_get_guint8(tvb, offset);
 255     descriptor_type = tvb_get_guint8(tvb, offset+1);
 256
 257     if (descriptor_type == CS_INTERFACE) {
 258         item = proto_tree_add_text(tree, tvb, offset, descriptor_len,
 259                 "AUDIO CONTROL INTERFACE DESCRIPTOR");
 260     }
 261     else if (descriptor_type == CS_ENDPOINT) {
 262         item = proto_tree_add_text(tree, tvb, offset, descriptor_len,
 263                 "AUDIO CONTROL ENDPOINT DESCRIPTOR");
 264     }
 265     else
 266         return 0;
 267
 268     desc_tree = proto_item_add_subtree(item, ett_usb_audio_desc);
 269
 270     dissect_usb_descriptor_header(desc_tree, tvb, offset,
 271             &aud_descriptor_type_vals_ext);
 272
 273     return descriptor_len;
 274 }
 275
 276
 277 /* dissector for usb midi bulk data */
 278 static int
 279 dissect_usb_audio_bulk(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void* data)
 280 {
 281     usb_conv_info_t *usb_conv_info = (usb_conv_info_t *)data;
 282     proto_tree *tree = NULL;
 283     guint offset;
 284     guint length = tvb_length(tvb);
 285
 286     col_set_str(pinfo->cinfo, COL_PROTOCOL, "USBAUDIO");
 287
 288     if (parent_tree)
 289     {
 290         proto_item *ti = NULL;
 291
 292         ti = proto_tree_add_protocol_format(parent_tree, proto_usb_audio, tvb, 0, -1, "USB Audio");
 293         tree = proto_item_add_subtree(ti, ett_usb_audio);
 294     }
 295
 296     switch (usb_conv_info->interfaceSubclass)
 297     {
 298         case AUDIO_SUBCLASS_MIDISTREAMING:
 299             offset = 0;
 300             col_set_str(pinfo->cinfo, COL_INFO, "USB-MIDI Event Packets");
 301
 302             while (offset < length)
 303             {
 304                 dissect_usb_midi_event(tvb, pinfo, tree, parent_tree, offset);
 305                 offset += 4;
 306             }
 307             break;
 308         default:
 309             offset = 0;
 310             proto_tree_add_expert(tree, pinfo, &ei_usb_audio_undecoded, tvb, offset, length - offset);
 311     }
 312
 313     return tvb_length(tvb);
 314 }
 315
 316 static void
 317 midi_data_reassemble_init(void)
 318 {
 319     reassembly_table_init(&midi_data_reassembly_table,
 320                           &addresses_reassembly_table_functions);
 321 }
 322
 323 void
 324 proto_register_usb_audio(void)
 325 {
 326     static hf_register_info hf[] = {
 327         { &hf_midi_cable_number,
 328             { "Cable Number", "usbaudio.midi.cable_number", FT_UINT8, BASE_HEX,
 329               NULL, 0xF0, NULL, HFILL }},
 330         { &hf_midi_code_index,
 331             { "Code Index", "usbaudio.midi.code_index", FT_UINT8, BASE_HEX,
 332               VALS(code_index_vals), 0x0F, NULL, HFILL }},
 333         { &hf_midi_event,
 334             { "MIDI Event", "usbaudio.midi.event", FT_UINT24, BASE_HEX,
 335               NULL, 0, NULL, HFILL }},
 336
 337         { &hf_sysex_msg_fragments,
 338             { "Message fragments", "usbaudio.sysex.fragments",
 339               FT_NONE, BASE_NONE, NULL, 0x00, NULL, HFILL }},
 340         { &hf_sysex_msg_fragment,
 341             { "Message fragment", "usbaudio.sysex.fragment",
 342               FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL }},
 343         { &hf_sysex_msg_fragment_overlap,
 344             { "Message fragment overlap", "usbaudio.sysex.fragment.overlap",
 345               FT_BOOLEAN, 0, NULL, 0x00, NULL, HFILL }},
 346         { &hf_sysex_msg_fragment_overlap_conflicts,
 347             { "Message fragment overlapping with conflicting data",
 348               "usbaudio.sysex.fragment.overlap.conflicts",
 349               FT_BOOLEAN, 0, NULL, 0x00, NULL, HFILL }},
 350         { &hf_sysex_msg_fragment_multiple_tails,
 351             { "Message has multiple tail fragments",
 352               "usbaudio.sysex.fragment.multiple_tails",
 353               FT_BOOLEAN, 0, NULL, 0x00, NULL, HFILL }},
 354         { &hf_sysex_msg_fragment_too_long_fragment,
 355             { "Message fragment too long", "usbaudio.sysex.fragment.too_long_fragment",
 356               FT_BOOLEAN, 0, NULL, 0x00, NULL, HFILL }},
 357         { &hf_sysex_msg_fragment_error,
 358             { "Message defragmentation error", "usbaudio.sysex.fragment.error",
 359               FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL }},
 360         { &hf_sysex_msg_fragment_count,
 361             { "Message fragment count", "usbaudio.sysex.fragment.count",
 362               FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL }},
 363         { &hf_sysex_msg_reassembled_in,
 364             { "Reassembled in", "usbaudio.sysex.reassembled.in",
 365               FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL }},
 366         { &hf_sysex_msg_reassembled_length,
 367             { "Reassembled length", "usbaudio.sysex.reassembled.length",
 368               FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL }},
 369         { &hf_sysex_msg_reassembled_data,
 370             { "Reassembled data", "usbaudio.sysex.reassembled.data",
 371               FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }},
 372     };
 373
 374     static gint *usb_audio_subtrees[] = {
 375         &ett_usb_audio,
 376         &ett_usb_audio_desc,
 377         &ett_sysex_msg_fragment,
 378         &ett_sysex_msg_fragments
 379     };
 380
 381     static ei_register_info ei[] = {
 382         { &ei_usb_audio_undecoded, { "usbaudio.undecoded", PI_UNDECODED, PI_WARN, "Not dissected yet (report to wireshark.org)", EXPFILL }},
 383     };
 384
 385     expert_module_t* expert_usb_audio;
 386
 387     proto_usb_audio = proto_register_protocol("USB Audio", "USBAUDIO", "usbaudio");
 388     proto_register_field_array(proto_usb_audio, hf, array_length(hf));
 389     proto_register_subtree_array(usb_audio_subtrees, array_length(usb_audio_subtrees));
 390     expert_usb_audio = expert_register_protocol(proto_usb_audio);
 391     expert_register_field_array(expert_usb_audio, ei, array_length(ei));
 392     register_init_routine(&midi_data_reassemble_init);
 393
 394     new_register_dissector("usbaudio", dissect_usb_audio_bulk, proto_usb_audio);
 395 }
 396
 397 void
 398 proto_reg_handoff_usb_audio(void)
 399 {
 400     dissector_handle_t usb_audio_bulk_handle, usb_audio_descr_handle;
 401
 402     usb_audio_descr_handle = new_create_dissector_handle(
 403             dissect_usb_audio_descriptor, proto_usb_audio);
 404     dissector_add_uint("usb.descriptor", IF_CLASS_AUDIO, usb_audio_descr_handle);
 405
 406     usb_audio_bulk_handle = find_dissector("usbaudio");
 407     dissector_add_uint("usb.bulk", IF_CLASS_AUDIO, usb_audio_bulk_handle);
 408
 409     sysex_handle = find_dissector("sysex");
 410 }
 411 /*
 412  * Editor modelines
 413  *
 414  * Local Variables:
 415  * c-basic-offset: 4
 416  * tab-width: 8
 417  * indent-tabs-mode: nil
 418  * End:
 419  *
 420  * ex: set shiftwidth=4 tabstop=8 expandtab:
 421  * :indentSize=4:tabSize=8:noTabs=true:
 422  */