![Michael Mann](/assets/img/avatar_default.png)
This saves many dissectors the need to find the data dissector and store a handle to it. There were also some that were finding it, but not using it. For others this was the only reason for their handoff function, so it could be eliminated. Change-Id: I5d3f951ee1daa3d30c060d21bd12bbc881a8027b Reviewed-on: https://code.wireshark.org/review/14530 Petri-Dish: Michael Mann <mmann78@netscape.net> Reviewed-by: Michael Mann <mmann78@netscape.net>
183 lines
5.1 KiB
C
183 lines
5.1 KiB
C
/* packet-loop.c
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* Routines for Ethernet loopback/Configuration Test Protocol dissection
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*
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* See
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*
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* http://stuff.mit.edu/people/jhawk/ctp.html
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "config.h"
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#include <epan/packet.h>
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#include <epan/etypes.h>
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void proto_register_loop(void);
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void proto_reg_handoff_loop(void);
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static int proto_loop = -1;
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static int hf_loop_skipcount = -1;
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static int hf_loop_function = -1;
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static int hf_loop_relevant_function = -1;
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static int hf_loop_receipt_number = -1;
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static int hf_loop_forwarding_address = -1;
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static gint ett_loop = -1;
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#define FUNC_REPLY 1
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#define FUNC_FORWARD_DATA 2
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static const value_string function_vals[] = {
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{ FUNC_REPLY, "Reply" },
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{ FUNC_FORWARD_DATA, "Forward Data" },
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{ 0, NULL }
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};
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static int
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dissect_loop(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
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{
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proto_tree *loop_tree = NULL;
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proto_item *ti;
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guint16 function;
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int offset = 0;
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int skip_offset;
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gboolean set_info = TRUE;
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gboolean more_function;
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tvbuff_t *next_tvb;
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "LOOP");
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col_clear(pinfo->cinfo, COL_INFO);
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if (tree) {
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ti = proto_tree_add_item(tree, proto_loop, tvb, offset, -1, ENC_NA);
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loop_tree = proto_item_add_subtree(ti, ett_loop);
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proto_tree_add_item(loop_tree, hf_loop_skipcount, tvb, offset, 2, ENC_LITTLE_ENDIAN);
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}
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skip_offset = 2 + tvb_get_letohs(tvb, offset);
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offset += 2;
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do {
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function = tvb_get_letohs(tvb, offset);
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if (offset == skip_offset) {
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col_add_str(pinfo->cinfo, COL_INFO,
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val_to_str(function, function_vals, "Unknown function (%u)"));
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proto_tree_add_uint(loop_tree, hf_loop_relevant_function, tvb, offset, 2, function);
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set_info = FALSE;
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}
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proto_tree_add_uint(loop_tree, hf_loop_function, tvb, offset, 2, function);
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offset += 2;
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switch (function) {
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case FUNC_REPLY:
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proto_tree_add_item(loop_tree, hf_loop_receipt_number, tvb, offset, 2,
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ENC_LITTLE_ENDIAN);
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offset += 2;
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more_function = FALSE;
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break;
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case FUNC_FORWARD_DATA:
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proto_tree_add_item(loop_tree, hf_loop_forwarding_address, tvb, offset,
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6, ENC_NA);
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offset += 6;
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more_function = TRUE;
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break;
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default:
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more_function = FALSE;
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break;
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}
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} while (more_function);
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if (set_info) {
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col_set_str(pinfo->cinfo, COL_INFO, "No valid function found");
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}
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if (tvb_reported_length_remaining(tvb, offset) > 0)
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{
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next_tvb = tvb_new_subset_remaining(tvb, offset);
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call_data_dissector(next_tvb, pinfo, tree);
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}
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return tvb_captured_length(tvb);
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}
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void
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proto_register_loop(void)
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{
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static hf_register_info hf[] = {
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{ &hf_loop_skipcount,
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{ "skipCount", "loop.skipcount",
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FT_UINT16, BASE_DEC, NULL, 0x0,
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NULL, HFILL }},
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{ &hf_loop_function,
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{ "Function", "loop.function",
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FT_UINT16, BASE_DEC, VALS(function_vals), 0x0,
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NULL, HFILL }},
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{ &hf_loop_relevant_function,
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{ "Relevant function", "loop.relevant_function",
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FT_UINT16, BASE_DEC, VALS(function_vals), 0x0,
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NULL, HFILL }},
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{ &hf_loop_receipt_number,
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{ "Receipt number", "loop.receipt_number",
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FT_UINT16, BASE_DEC, NULL, 0x0,
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NULL, HFILL }},
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{ &hf_loop_forwarding_address,
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{ "Forwarding address", "loop.forwarding_address",
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FT_ETHER, BASE_NONE, NULL, 0x0,
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NULL, HFILL }},
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};
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static gint *ett[] = {
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&ett_loop,
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};
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proto_loop = proto_register_protocol("Configuration Test Protocol (loopback)",
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"LOOP", "loop");
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proto_register_field_array(proto_loop, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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}
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void
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proto_reg_handoff_loop(void)
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{
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dissector_handle_t loop_handle;
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loop_handle = create_dissector_handle(dissect_loop, proto_loop);
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dissector_add_uint("ethertype", ETHERTYPE_LOOP, loop_handle);
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}
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/*
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* Editor modelines - http://www.wireshark.org/tools/modelines.html
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*
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* Local Variables:
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* c-basic-offset: 2
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* tab-width: 8
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* indent-tabs-mode: nil
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* End:
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*
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* ex: set shiftwidth=2 tabstop=8 expandtab:
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* :indentSize=2:tabSize=8:noTabs=true:
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*/
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