/* packet-pw-hdlc.c * Routines for HDLC PW dissection as per RFC4618. * Copyright 2009, Dmitry Trebich, Artem Tamazov * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later * * History: * --------------------------------- * 02.03.2009 Initial implementation, supports: * - HDLC mode (rfc4618 5.1), no CW, payload is PPP (PPP in HDLC-like Framing (rfc1662)). * - FR port mode (rfc4618 5.2), no CW. * * [informative: Not supported yet: * - All kinds of HDLC PW with CW. * - PPP mode (rfc4618 5.3). * - For HDLC mode, decoding payloads other than PPP.] */ #include "config.h" #include void proto_register_pw_hdlc(void); void proto_reg_handoff_pw_hdlc(void); static dissector_handle_t ppp_handle; static dissector_handle_t fr_handle; static dissector_handle_t pw_hdlc_nocw_fr_handle; static dissector_handle_t pw_ppp_handle; static int proto_pw_hdlc_nocw_fr; static int proto_pw_hdlc_nocw_hdlc_ppp; static int ett_pw_hdlc; /* static int hf_pw_hdlc; */ static int hf_pw_hdlc_address_field; static int hf_pw_hdlc_address; static int hf_pw_hdlc_cr_bit; static int hf_pw_hdlc_control_field; static int hf_pw_hdlc_pf_bit; static int hf_pw_hdlc_modifier; static int hf_pw_hdlc_frame; static const value_string pw_hdlc_modifier_vals[] = { {0x00, "UI - Unnumbered information" }, {0x08, "UP - Unnumbered poll" }, {0x10, "DISC/RD - Disconnect/Request disconnect" }, {0x18, "UA - Unnumbered acknowledgment" }, {0x20, "SNRM - Set normal response mode" }, {0x38, "TEST - Test" }, {0x01, "SIM/RIM - Set initialization mode/Request initialization mode" }, {0x21, "FRMR - Frame reject" }, {0x03, "SARM/DM - Set asynchronous response mode/Disconnect mode" }, {0x0B, "SABM - Set asynchronous balanced mode" }, {0x13, "SARME - Set asynchronous response extended mode" }, {0x1B, "SABME - Set asynchronous balanced extended mode" }, {0x23, "RSET - Reset" }, {0x2B, "XID - Exchange identification" }, {0x33, "SNRME - Set normal response extended mode" }, {0, NULL } }; static int dissect_pw_hdlc_nocw_fr( tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data _U_ ) { return call_dissector( fr_handle, tvb, pinfo, tree ); } static int dissect_pw_hdlc_nocw_hdlc_ppp( tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data _U_ ) { if (tvb_reported_length_remaining(tvb, 0) < 2) { return 0; } if (tree) { proto_tree *tr; proto_item *item; proto_item *item_address; proto_item *item_control; uint8_t addr; uint8_t control; addr = tvb_get_uint8(tvb, 0); control = tvb_get_uint8(tvb, 1); item = proto_tree_add_item( tree, proto_pw_hdlc_nocw_hdlc_ppp, tvb, 0, 2, ENC_NA ); tr = proto_item_add_subtree( item, ett_pw_hdlc ); item_address = proto_tree_add_item( tr, hf_pw_hdlc_address_field, tvb, 0, 1, ENC_BIG_ENDIAN ); item_control = proto_tree_add_item( tr, hf_pw_hdlc_control_field, tvb, 1, 1, ENC_BIG_ENDIAN ); tr = proto_item_add_subtree( item_address, ett_pw_hdlc ); if ( 0x3F == (( addr & 0xFC ) >> 2 )) proto_tree_add_uint_format_value( tr, hf_pw_hdlc_address, tvb, 0, 1, 0xFC, "0x%x (All stations)", 0x3F ); else proto_tree_add_uint( tr, hf_pw_hdlc_address, tvb, 0, 1, ( addr & 0xFC ) >> 2 ); proto_tree_add_uint( tr, hf_pw_hdlc_cr_bit, tvb, 0, 1, ( addr & 2 ) >> 1 ); tr = proto_item_add_subtree( item_control, ett_pw_hdlc ); if ( control & 1 ) { if ( control & 2 ) { proto_tree_add_uint_format( tr, hf_pw_hdlc_frame, tvb, 1, 1, control, "U frame" ); proto_tree_add_uint( tr, hf_pw_hdlc_pf_bit, tvb, 1, 1, ( control & 0x10 ) >> 4 ); proto_tree_add_uint( tr, hf_pw_hdlc_modifier, tvb, 1, 1, (control & 0xEC) >> 2); } else { proto_tree_add_uint_format( tr, hf_pw_hdlc_frame, tvb, 1, 1, control, "S frame" ); } } else { proto_tree_add_uint_format( tr, hf_pw_hdlc_frame, tvb, 1, 1, control, "I frame" ); } } call_dissector( ppp_handle, tvb_new_subset_remaining(tvb, 2), pinfo, tree ); return tvb_captured_length(tvb); } void proto_register_pw_hdlc(void) { static hf_register_info hf[] = { #if 0 { &hf_pw_hdlc, { "PW HDLC", "pw_hdlc", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL } }, #endif { &hf_pw_hdlc_address_field, { "Address field", "pw_hdlc.address_field", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_pw_hdlc_address, { "Address", "pw_hdlc.address", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_pw_hdlc_cr_bit, { "C/R bit", "pw_hdlc.cr_bit", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_pw_hdlc_control_field, { "Control field", "pw_hdlc.control_field", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_pw_hdlc_pf_bit, { "Poll/Final bit", "pw_hdlc.pf_bit", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_pw_hdlc_modifier, { "Modifier", "pw_hdlc.modifier", FT_UINT8, BASE_HEX, VALS(pw_hdlc_modifier_vals), 0x0, NULL, HFILL } }, { &hf_pw_hdlc_frame, { "Frame type", "pw_hdlc.frame", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, }; static int *ett[] = { &ett_pw_hdlc }; proto_pw_hdlc_nocw_fr = proto_register_protocol("HDLC PW, FR port mode (no CW)", /*not displayed*/ "HDLC PW, FR port mode (no CW)", "pw_hdlc_nocw_fr" ); proto_pw_hdlc_nocw_hdlc_ppp = proto_register_protocol("HDLC-like framing for PPP", "HDLC PW with PPP payload (no CW)", "pw_hdlc_nocw_hdlc_ppp" ); proto_register_field_array(proto_pw_hdlc_nocw_fr, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); pw_hdlc_nocw_fr_handle = register_dissector("pw_hdlc_nocw_fr", dissect_pw_hdlc_nocw_fr, proto_pw_hdlc_nocw_fr ); pw_ppp_handle = register_dissector("pw_hdlc_nocw_hdlc_ppp", dissect_pw_hdlc_nocw_hdlc_ppp, proto_pw_hdlc_nocw_hdlc_ppp ); } void proto_reg_handoff_pw_hdlc(void) { dissector_add_for_decode_as( "mpls.label", pw_hdlc_nocw_fr_handle ); dissector_add_for_decode_as( "mpls.label", pw_ppp_handle ); dissector_add_for_decode_as( "mpls.pfn", pw_hdlc_nocw_fr_handle ); dissector_add_for_decode_as( "mpls.pfn", pw_ppp_handle ); ppp_handle = find_dissector_add_dependency( "ppp", proto_pw_hdlc_nocw_hdlc_ppp ); fr_handle = find_dissector_add_dependency( "fr", proto_pw_hdlc_nocw_fr ); } /* * 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: */