/* packet-dpnss-link.c * Routines for DPNSS/DASS2 link layer dissection * Copyright 2009, Rolf Fiedler * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ /* References: * BTNR188 * ND1301:2001/03 http://www.nicc.org.uk/nicc-public/Public/interconnectstandards/dpnss/nd1301_2004_11.pdf */ #include "config.h" #include #include void proto_register_dpnss_link(void); void proto_reg_handoff_dpnss_link(void); static dissector_handle_t dpnss_handle; /* DPNSS UI frame dissector */ #define LINK_HEADER_SIZE 3 static int proto_dpnss_link; static int hf_dpnss_link_address_framegroup; static int hf_dpnss_link_address_crbit; static int hf_dpnss_link_address_extension; static int hf_dpnss_link_address2_reserved; static int hf_dpnss_link_address2_dlcId; static int hf_dpnss_link_address2_dlcIdNr; static int hf_dpnss_link_address2_extension; static int hf_dpnss_link_control_frameType; static const value_string dpnss_link_framegroup_vals[] = { { 0x11, "Information Frame" }, { 0x03, "Control Frame" }, { 0, NULL } }; static const value_string dpnss_link_crbit_vals[] = { { 0x0, "Command/Response Bit Cleared" }, { 0x1, "Command/Response Bit Set" }, { 0, NULL } }; static const value_string dpnss_link_extend_vals[] = { { 0x0, "Extended to next octet" }, { 0x1, "Final octet" }, { 0, NULL } }; static const value_string dpnss_link_reserved_vals[] = { { 0x0, "Reserved" }, { 0x1, "Reserved" }, { 0, NULL } }; static const value_string dpnss_link_dlcId_vals[] = { { 0x0, "Real Channel" }, { 0x1, "Virtual Channel" }, { 0, NULL } }; #define FRAME_TYPE_UI_EVEN 0x03 #define FRAME_TYPE_UI_ODD 0x13 #define FRAME_TYPE_SABMR 0xef #define FRAME_TYPE_UA 0x63 static const value_string dpnss_link_frameType_vals[] = { { FRAME_TYPE_UI_EVEN, "UI (even)" }, { FRAME_TYPE_UI_ODD, "UI (odd)" }, { FRAME_TYPE_SABMR, "SABMR" }, { FRAME_TYPE_UA, "UA" }, { 0, NULL } }; static int ett_dpnss_link; static dissector_handle_t dpnss_link_handle; /* Code to actually dissect the packets */ static int dissect_dpnss_link(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { proto_item *item; proto_tree *dpnss_link_tree; uint8_t octet; tvbuff_t *protocol_data_tvb; uint16_t protocol_data_length; bool uton; uton = pinfo->pseudo_header->l1event.uton; /* Make entries in src and dst column */ col_set_str(pinfo->cinfo, COL_DEF_SRC, uton?"TE":"NT"); col_set_str(pinfo->cinfo, COL_DEF_DST, uton?"NT":"TE"); /* Make entries in Protocol column and Info column on summary display */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "DPNSS"); item = proto_tree_add_item(tree, proto_dpnss_link, tvb, 0, -1, ENC_NA); dpnss_link_tree = proto_item_add_subtree(item, ett_dpnss_link); proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address_framegroup, tvb, 0, 1, ENC_BIG_ENDIAN); proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address_crbit, tvb, 0, 1, ENC_BIG_ENDIAN); proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address_extension, tvb, 0, 1, ENC_BIG_ENDIAN); proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address2_reserved, tvb, 1, 1, ENC_BIG_ENDIAN); proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address2_dlcId, tvb, 1, 1, ENC_BIG_ENDIAN); proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address2_dlcIdNr, tvb, 1, 1, ENC_BIG_ENDIAN); proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address2_extension, tvb, 1, 1, ENC_BIG_ENDIAN); /* * XXX - DPNSS's layer 2 protocol appears to be Yet Another * HDLC Derivative; should this use the xDLC control field * dissector code? */ proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_control_frameType, tvb, 2, 1, ENC_BIG_ENDIAN); octet = tvb_get_uint8(tvb, 2); switch (octet){ case FRAME_TYPE_UI_EVEN: case FRAME_TYPE_UI_ODD: protocol_data_length=tvb_reported_length(tvb)-LINK_HEADER_SIZE; protocol_data_tvb=tvb_new_subset_length(tvb, LINK_HEADER_SIZE, protocol_data_length); if (dpnss_handle && protocol_data_length>0) { call_dissector(dpnss_handle, protocol_data_tvb, pinfo, tree); } break; default: break; } return tvb_captured_length(tvb); } /* Register the protocol with Wireshark */ void proto_register_dpnss_link(void) { static hf_register_info hf[] = { { &hf_dpnss_link_address_framegroup, { "Frame Group", "dpnss_link.framegroup", FT_UINT8, BASE_DEC, VALS(dpnss_link_framegroup_vals), 0xfc, NULL, HFILL } }, { &hf_dpnss_link_address_crbit, { "C/R Bit", "dpnss_link.crbit", FT_UINT8, BASE_DEC, VALS(dpnss_link_crbit_vals), 0x02, NULL, HFILL } }, { &hf_dpnss_link_address_extension, { "Extension", "dpnss_link.extension", FT_UINT8, BASE_DEC, VALS(dpnss_link_extend_vals), 0x01, NULL, HFILL } }, { &hf_dpnss_link_address2_reserved, { "Reserved", "dpnss_link.reserved", FT_UINT8, BASE_DEC, VALS(dpnss_link_reserved_vals), 0x80, NULL, HFILL } }, { &hf_dpnss_link_address2_dlcId, { "DLC ID", "dpnss_link.dlcId", FT_UINT8, BASE_DEC, VALS(dpnss_link_dlcId_vals), 0x40, NULL, HFILL } }, { &hf_dpnss_link_address2_dlcIdNr, { "DLC ID Number", "dpnss_link.dlcIdNr", FT_UINT8, BASE_DEC, NULL, 0x3e, NULL, HFILL } }, { &hf_dpnss_link_address2_extension, { "Extension", "dpnss_link.extension2", FT_UINT8, BASE_DEC, VALS(dpnss_link_extend_vals), 0x01, NULL, HFILL } }, { &hf_dpnss_link_control_frameType, { "Frame Type", "dpnss_link.frameType", FT_UINT8, BASE_DEC, VALS(dpnss_link_frameType_vals), 0x0, NULL, HFILL } } }; static int *ett[] = { &ett_dpnss_link }; /* Register the protocol name and description */ proto_dpnss_link = proto_register_protocol("Digital Private Signalling System No 1 Link Layer", "DPNSS Link", "dpnss_link"); dpnss_link_handle = register_dissector("dpnss_link", dissect_dpnss_link, proto_dpnss_link); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_dpnss_link, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); } void proto_reg_handoff_dpnss_link(void) { dissector_add_uint("wtap_encap", WTAP_ENCAP_DPNSS, dpnss_link_handle); dpnss_handle = find_dissector_add_dependency("dpnss", proto_dpnss_link); } /* * Editor modelines - https://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 8 * tab-width: 8 * indent-tabs-mode: t * End: * * vi: set shiftwidth=8 tabstop=8 noexpandtab: * :indentSize=8:tabSize=8:noTabs=false: */