/* packet-amr.c * Routines for AMR dissection * Copyright 2005, Anders Broman * * $Id$ * * Ethereal - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * References: * RFC 3267 * http://www.ietf.org/rfc/rfc3267.txt?number=3267 */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include #include #include "prefs.h" /* Initialize the protocol and registered fields */ static int proto_amr = -1; static int hf_amr_cmr = -1; static int hf_amr_reserved = -1; static int hf_amr_toc_f = -1; static int hf_amr_toc_ft = -1; static int hf_amr_toc_q = -1; /* Initialize the subtree pointers */ static int ett_amr = -1; static int ett_amr_toc = -1; /* The dynamic payload type which will be dissected as AMR */ static guint dynamic_payload_type = 0; static guint temp_dynamic_payload_type = 0; /* Currently only octet aligned works */ static gboolean octet_aligned = TRUE; static const value_string amr_codec_mode_request_vals[] = { {0, "AMR 4,75 kbit/s"}, {1, "AMR 5,15 kbit/s"}, {2, "AMR 5,90 kbit/s"}, {3, "AMR 6,70 kbit/s (PDC-EFR)"}, {4, "AMR 7,40 kbit/s (TDMA-EFR)"}, {5, "AMR 7,95 kbit/s"}, {6, "AMR 10,2 kbit/s"}, {7, "AMR 12,2 kbit/s (GSM-EFR)"}, {8, "AMR SID"}, {9, "GSM-EFR SID"}, {10, "TDMA-EFR SID"}, {11, "PDC-EFR SID"}, /* {12-14 - - For future use */ {15, "No Data (No transmission/No reception)"}, { 0, NULL } }; static const true_false_string toc_f_bit_vals = { "Followed by another speech frame", "Last frame in this payload" }; static const true_false_string toc_q_bit_vals = { "Ok", "Severely damaged frame" }; /* Code to actually dissect the packets */ static void dissect_amr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { int offset = 0; int toc_offset = 0; guint octet; /* Set up structures needed to add the protocol subtree and manage it */ proto_item *ti,*toc_item; proto_tree *amr_tree, *toc_tree; /* Make entries in Protocol column and Info column on summary display */ if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "AMR"); if (tree) { ti = proto_tree_add_item(tree, proto_amr, tvb, 0, -1, FALSE); amr_tree = proto_item_add_subtree(ti, ett_amr); /* add an item to the subtree, see section 1.6 for more information */ proto_tree_add_item(amr_tree, hf_amr_cmr, tvb, offset, 1, FALSE); if ( !octet_aligned ) return; /* only handle octet aligned for now */ proto_tree_add_item(amr_tree, hf_amr_reserved, tvb, offset, 1, FALSE); offset++; toc_offset = offset; /* If interleaced ILL and ILP follows here */ /* Payload Table of Contents * A ToC entry takes the following format in octet-aligned mode: * * 0 1 2 3 4 5 6 7 * +-+-+-+-+-+-+-+-+ * |F| FT |Q|P|P| * +-+-+-+-+-+-+-+-+ */ octet = tvb_get_guint8(tvb,offset); toc_item = proto_tree_add_text(amr_tree, tvb, offset, -1, "Payload Table of Contents"); toc_tree = proto_item_add_subtree(toc_item, ett_amr_toc); while ( ( octet& 0x80 ) == 0x80 ){ octet = tvb_get_guint8(tvb,offset); proto_tree_add_item(amr_tree, hf_amr_toc_f, tvb, offset, 1, FALSE); proto_tree_add_item(amr_tree, hf_amr_toc_ft, tvb, offset, 1, FALSE); proto_tree_add_item(amr_tree, hf_amr_toc_q, tvb, offset, 1, FALSE); offset++; } /* Continue adding tree items to process the packet here */ }/* if tree */ /* If this protocol has a sub-dissector call it here, see section 1.8 */ } /* Register the protocol with Ethereal */ /* If this dissector uses sub-dissector registration add a registration routine. This format is required because a script is used to find these routines and create the code that calls these routines. */ void proto_reg_handoff_amr(void) { dissector_handle_t amr_handle; static int amr_prefs_initialized = FALSE; amr_handle = create_dissector_handle(dissect_amr, proto_amr); if (!amr_prefs_initialized) { amr_prefs_initialized = TRUE; } else { if ( dynamic_payload_type > 95 ) dissector_delete("rtp.pt", dynamic_payload_type, amr_handle); } dynamic_payload_type = temp_dynamic_payload_type; if ( dynamic_payload_type > 95 ){ dissector_add("rtp.pt", dynamic_payload_type, amr_handle); } dissector_add_string("rtp_dyn_payload_type","amr", amr_handle); } /* this format is require because a script is used to build the C function that calls all the protocol registration. */ void proto_register_amr(void) { module_t *amr_module; /* Setup list of header fields See Section 1.6.1 for details*/ static hf_register_info hf[] = { { &hf_amr_cmr, { "CMR", "amr.cmr", FT_UINT8, BASE_DEC, VALS(amr_codec_mode_request_vals), 0xf0, "codec mode request", HFILL } }, { &hf_amr_reserved, { "Reserved", "amr.reserved", FT_UINT8, BASE_DEC, NULL, 0x0f, "Reserved bits", HFILL } }, { &hf_amr_toc_f, { "F bit", "amr.toc.f", FT_BOOLEAN, 8, TFS(&toc_f_bit_vals), 0x80, "F bit", HFILL } }, { &hf_amr_toc_ft, { "FT bits", "amr.toc.ft", FT_UINT8, BASE_DEC, VALS(amr_codec_mode_request_vals), 0x78, "FT bits", HFILL } }, { &hf_amr_toc_q, { "Q bit", "amr.toc.q", FT_BOOLEAN, 8, TFS(&toc_q_bit_vals), 0x04, "Frame quality indicator bit", HFILL } }, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_amr, &ett_amr_toc, }; /* Register the protocol name and description */ proto_amr = proto_register_protocol("Adaptive Multi-Rate","AMR", "amr"); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_amr, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); /* Register a configuration option for port */ amr_module = prefs_register_protocol(proto_amr, proto_reg_handoff_amr); prefs_register_uint_preference(amr_module, "dynamic.payload.type", "AMR dynamic payload type", "The dynamic payload type which will be interpretyed as AMR", 10, &temp_dynamic_payload_type); }