/* packet-pn532_hci.c * Routines for NXP PN532 HCI Protocol * * http://www.nxp.com/documents/user_manual/141520.pdf * * Copyright 2013, Michal Labedzki for Tieto Corporation * * Wireshark - 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 thehf_class * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "config.h" #include #include #include #include "packet-usb.h" static int proto_pn532_hci = -1; static int hf_preamble = -1; static int hf_start_code = -1; static int hf_length = -1; static int hf_length_checksum = -1; static int hf_length_checksum_status = -1; static int hf_extended_length = -1; static int hf_packet_code = -1; static int hf_postable = -1; static int hf_specific_application_level_error_code = -1; static int hf_data_checksum = -1; static int hf_data_checksum_status = -1; static int hf_ignored = -1; static gint ett_pn532_hci = -1; static expert_field ei_invalid_length_checksum = EI_INIT; static expert_field ei_invalid_data_checksum = EI_INIT; static dissector_handle_t pn532_handle; static dissector_handle_t pn532_hci_handle; static const value_string packet_code_vals[] = { { 0x00FF, "ACK Frame" }, { 0x01FF, "Error Frame" }, { 0xFF00, "NACK Frame" }, { 0xFFFF, "Extended Information Frame" }, { 0, NULL } }; void proto_register_pn532_hci(void); void proto_reg_handoff_pn532_hci(void); static gint dissect_pn532_hci(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data) { proto_item *main_item; proto_tree *main_tree; gint offset = 0; tvbuff_t *next_tvb; guint16 packet_code; guint16 length; guint8 checksum; usb_conv_info_t *usb_conv_info; /* Reject the packet if data is NULL */ if (data == NULL) return 0; usb_conv_info = (usb_conv_info_t *)data; length = tvb_captured_length_remaining(tvb, offset); if (length < 6) return offset; col_set_str(pinfo->cinfo, COL_PROTOCOL, "PN532_HCI"); col_clear(pinfo->cinfo, COL_INFO); main_item = proto_tree_add_item(tree, proto_pn532_hci, tvb, offset, -1, ENC_NA); main_tree = proto_item_add_subtree(main_item, ett_pn532_hci); length = 0; while (tvb_captured_length_remaining(tvb, length) >= 2 && tvb_get_ntohs(tvb, length) != 0x00FF) { length += 1; } if (length) { proto_tree_add_item(main_tree, hf_preamble, tvb, offset, length, ENC_NA); offset += length; } proto_tree_add_item(main_tree, hf_start_code, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; packet_code = tvb_get_ntohs(tvb, offset); if (packet_code == 0x00FF) { /* ACK Frame */ col_set_str(pinfo->cinfo, COL_INFO, val_to_str_const(packet_code, packet_code_vals, "Unknown frame")); proto_tree_add_item(main_tree, hf_packet_code, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; } else if (packet_code == 0xFF00) { /* NACK Frame */ col_set_str(pinfo->cinfo, COL_INFO, val_to_str_const(packet_code, packet_code_vals, "Unknown frame")); proto_tree_add_item(main_tree, hf_packet_code, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; } else if (packet_code == 0x01FF) { /* Error Frame */ col_set_str(pinfo->cinfo, COL_INFO, val_to_str_const(packet_code, packet_code_vals, "Unknown frame")); proto_tree_add_item(main_tree, hf_packet_code, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; proto_tree_add_item(main_tree, hf_specific_application_level_error_code, tvb, offset, 1, ENC_BIG_ENDIAN); offset += 1; } else if (packet_code == 0xFFFF) { /* Extended Information Frame */ col_set_str(pinfo->cinfo, COL_INFO, "Extended Information Frame"); proto_tree_add_item(main_tree, hf_extended_length, tvb, offset, 2, ENC_BIG_ENDIAN); length = tvb_get_ntohs(tvb, offset); offset += 2; checksum = (length >> 8) + (length & 0xFF) + tvb_get_guint8(tvb, offset); proto_tree_add_checksum(main_tree, tvb, offset, hf_length_checksum, hf_length_checksum_status, &ei_invalid_length_checksum, pinfo, checksum, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY|PROTO_CHECKSUM_ZERO); offset += 1; next_tvb = tvb_new_subset_length(tvb, offset, length); call_dissector_with_data(pn532_handle, next_tvb, pinfo, tree, usb_conv_info); offset += length; checksum = tvb_get_guint8(tvb, offset); while (length) { checksum += tvb_get_guint8(tvb, offset - length); length -= 1; } proto_tree_add_checksum(main_tree, tvb, offset, hf_data_checksum, hf_data_checksum_status, &ei_invalid_data_checksum, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY|PROTO_CHECKSUM_ZERO); offset += 1; } else { /* Normal Information Frame */ col_set_str(pinfo->cinfo, COL_INFO, "Normal Information Frame"); proto_tree_add_item(main_tree, hf_length, tvb, offset, 1, ENC_BIG_ENDIAN); length = tvb_get_guint8(tvb, offset); offset += 1; checksum = length + tvb_get_guint8(tvb, offset); proto_tree_add_checksum(main_tree, tvb, offset, hf_length_checksum, hf_length_checksum_status, &ei_invalid_length_checksum, pinfo, checksum, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY|PROTO_CHECKSUM_ZERO); offset += 1; next_tvb = tvb_new_subset_length(tvb, offset, length); call_dissector_with_data(pn532_handle, next_tvb, pinfo, tree, usb_conv_info); offset += length; proto_tree_add_item(main_tree, hf_data_checksum, tvb, offset, 1, ENC_BIG_ENDIAN); checksum = tvb_get_guint8(tvb, offset); while (length) { checksum += tvb_get_guint8(tvb, offset - length); length -= 1; } if (checksum != 0) { proto_tree_add_expert(main_tree, pinfo, &ei_invalid_data_checksum, tvb, offset, 1); } offset += 1; } length = 0; if (tvb_captured_length_remaining(tvb, offset) == 1) { length = 1; } else while (tvb_captured_length_remaining(tvb, offset + length) >= 2 && tvb_get_ntohs(tvb, offset + length) != 0x00FF) { length += 1; } if (length) { proto_tree_add_item(main_tree, hf_postable, tvb, offset, length, ENC_NA); offset += length; } if (tvb_captured_length_remaining(tvb, offset)) { proto_tree_add_item(main_tree, hf_ignored, tvb, offset, tvb_captured_length_remaining(tvb, offset), ENC_NA); offset += tvb_captured_length_remaining(tvb, offset); } return offset; } void proto_register_pn532_hci(void) { module_t *module; expert_module_t *expert_module; static hf_register_info hf[] = { { &hf_preamble, { "Preamble", "pn532_hci.preamble", FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL } }, { &hf_start_code, { "Start Code", "pn532_hci.start_code", FT_UINT16, BASE_HEX, NULL, 0x00, NULL, HFILL } }, { &hf_packet_code, { "Packet Code", "pn532_hci.packet_code", FT_UINT16, BASE_HEX, VALS(packet_code_vals), 0x00, NULL, HFILL } }, { &hf_length, { "Length", "pn532_hci.length", FT_UINT8, BASE_DEC, NULL, 0x00, NULL, HFILL } }, { &hf_extended_length, { "Extended Length", "pn532_hci.extended_length", FT_UINT16, BASE_DEC, NULL, 0x00, NULL, HFILL } }, { &hf_length_checksum, { "Length Checksum", "pn532_hci.length_checksum", FT_UINT8, BASE_HEX, NULL, 0x00, NULL, HFILL } }, { &hf_length_checksum_status, { "Length Checksum Status", "pn532_hci.length_checksum.status", FT_UINT8, BASE_NONE, VALS(proto_checksum_vals), 0x00, NULL, HFILL } }, { &hf_data_checksum, { "Data Checksum", "pn532_hci.data_checksum", FT_UINT8, BASE_HEX, NULL, 0x00, NULL, HFILL } }, { &hf_data_checksum_status, { "Data Checksum Status", "pn532_hci.data_checksum.status", FT_UINT8, BASE_NONE, VALS(proto_checksum_vals), 0x00, NULL, HFILL } }, { &hf_specific_application_level_error_code, { "Specific Application Level Error Code","pn532_hci.specific_application_level_error_code", FT_UINT8, BASE_HEX, NULL, 0x00, NULL, HFILL } }, { &hf_postable, { "Postamble", "pn532_hci.postamble", FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL } }, { &hf_ignored, { "Ignored", "pn532_hci.ignored", FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL } } }; static gint *ett[] = { &ett_pn532_hci }; static ei_register_info ei[] = { { &ei_invalid_length_checksum, { "pn532_hci.expert.invalid_length_checksum", PI_PROTOCOL, PI_WARN, "Invalid Length Checksum", EXPFILL }}, { &ei_invalid_data_checksum, { "pn532_hci.expert.invalid_data_checksum", PI_PROTOCOL, PI_WARN, "Invalid Data Checksum", EXPFILL }}, }; proto_pn532_hci = proto_register_protocol("NXP PN532 HCI", "PN532_HCI", "pn532_hci"); pn532_hci_handle = register_dissector("pn532_hci", dissect_pn532_hci, proto_pn532_hci); proto_register_field_array(proto_pn532_hci, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); expert_module = expert_register_protocol(proto_pn532_hci); expert_register_field_array(expert_module, ei, array_length(ei)); module = prefs_register_protocol(proto_pn532_hci, NULL); prefs_register_static_text_preference(module, "version", "PN532 HCI protocol version is based on: \"UM0701-02; PN532 User Manual\"", "Version of protocol supported by this dissector."); } void proto_reg_handoff_pn532_hci(void) { pn532_handle = find_dissector_add_dependency("pn532", proto_pn532_hci); dissector_add_uint("usb.product", (0x04e6 << 16) | 0x5591, pn532_hci_handle); dissector_add_for_decode_as("usb.device", pn532_hci_handle); dissector_add_for_decode_as("usb.protocol", pn532_hci_handle); } /* * Editor modelines - http://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 4 * tab-width: 8 * indent-tabs-mode: nil * End: * * vi: set shiftwidth=4 tabstop=8 expandtab: * :indentSize=4:tabSize=8:noTabs=true: */