1 /* packet-cisco-ttag.c 2 * Routines for dissection of Cisco's ttag protocol. 3 * Based on packet-cisco-metadata.c 4 * 5 * Copyright 2016 by Jaap Keuter (jkeuter[AT]xs4all.nl) 6 * 7 * Wireshark - Network traffic analyzer 8 * By Gerald Combs <gerald@wireshark.org> 9 * Copyright 1998 Gerald Combs 10 * 11 * SPDX-License-Identifier: GPL-2.0-or-later 12 */ 13 14 #include "config.h" 15 16 #include <epan/packet.h> 17 #include <epan/etypes.h> 18 #include <epan/to_str.h> 19 20 void proto_register_ttag(void); 21 void proto_reg_handoff_ttag(void); 22 23 static dissector_handle_t ethertype_handle; 24 25 static int proto_ttag = -1; 26 27 static int hf_ttag_time_stamp = -1; 28 static int hf_ttag_eth_type = -1; 29 30 static gint ett_ttag = -1; 31 32 static int 33 dissect_ttag(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) 34 { 35 guint64 timestamp_value; 36 nstime_t timestamp; 37 guint16 encap_proto; 38 ethertype_data_t ethertype_data; 39 40 proto_tree *ttag_tree; 41 proto_item *ti; 42 gint offset = 0; 43 44 col_set_str(pinfo->cinfo, COL_PROTOCOL, "TTAG"); 45 col_clear(pinfo->cinfo, COL_INFO); 46 47 ti = proto_tree_add_item(tree, proto_ttag, tvb, 0, 8, ENC_NA); 48 ttag_tree = proto_item_add_subtree(ti, ett_ttag); 49 50 timestamp_value = tvb_get_guint48(tvb, offset, ENC_BIG_ENDIAN); 51 timestamp.secs = (time_t) (timestamp_value / G_GUINT64_CONSTANT(1000000000)); 52 timestamp.nsecs = (guint32)(timestamp_value - (timestamp.secs * G_GUINT64_CONSTANT(1000000000))); 53 54 proto_item_append_text(ti, ", Timestamp: %s", rel_time_to_secs_str(pinfo->pool, ×tamp)); 55 56 proto_tree_add_time(ttag_tree, hf_ttag_time_stamp, tvb, offset, 6, ×tamp); 57 offset += 6; 58 59 encap_proto = tvb_get_ntohs(tvb, offset); 60 proto_tree_add_uint(ttag_tree, hf_ttag_eth_type, tvb, offset, 2, encap_proto); 61 offset += 2; 62 63 ethertype_data.etype = encap_proto; 64 ethertype_data.payload_offset = offset; 65 ethertype_data.fh_tree = ttag_tree; 66 /* ttag doesn't define a trailer, but there's no way to tell Ethertype dissector that. 67 * At least use the correct header field to reflect that and allow proper filter expression, 68 * although it will still be attached to our tree instead of Ethernet II. 69 */ 70 ethertype_data.trailer_id = proto_registrar_get_id_byname("eth.trailer"); 71 ethertype_data.fcs_len = 0; 72 73 call_dissector_with_data(ethertype_handle, tvb, pinfo, tree, ðertype_data); 74 75 return tvb_captured_length(tvb); 76 } 77 78 void 79 proto_register_ttag(void) 80 { 81 static hf_register_info hf[] = { 82 { &hf_ttag_time_stamp, 83 { "Time stamp", "ttag.time_stamp", FT_RELATIVE_TIME, 0, NULL, 0x0, NULL, HFILL } 84 }, 85 { &hf_ttag_eth_type, 86 { "Type", "ttag.type", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0, NULL, HFILL } 87 } 88 }; 89 90 static gint *ett[] = { 91 &ett_ttag 92 }; 93 94 proto_ttag = proto_register_protocol("Cisco ttag", "Cisco ttag", "ttag"); 95 proto_register_field_array(proto_ttag, hf, array_length(hf)); 96 proto_register_subtree_array(ett, array_length(ett)); 97 } 98 99 void 100 proto_reg_handoff_ttag(void) 101 { 102 dissector_handle_t ttag_handle; 103 104 ethertype_handle = find_dissector_add_dependency("ethertype", proto_ttag); 105 106 ttag_handle = create_dissector_handle(dissect_ttag, proto_ttag); 107 dissector_add_for_decode_as("ethertype", ttag_handle); 108 } 109 110 /* 111 * Editor modelines - https://www.wireshark.org/tools/modelines.html 112 * 113 * Local variables: 114 * c-basic-offset: 4 115 * tab-width: 8 116 * indent-tabs-mode: nil 117 * End: 118 * 119 * vi: set shiftwidth=4 tabstop=8 expandtab: 120 * :indentSize=4:tabSize=8:noTabs=true: 121 */ 122