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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
commit | e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc (patch) | |
tree | 68cb5ef9081156392f1dd62a00c6ccc1451b93df /epan/dissectors/packet-loop.c | |
parent | Initial commit. (diff) | |
download | wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.tar.xz wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.zip |
Adding upstream version 4.2.2.upstream/4.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'epan/dissectors/packet-loop.c')
-rw-r--r-- | epan/dissectors/packet-loop.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/epan/dissectors/packet-loop.c b/epan/dissectors/packet-loop.c new file mode 100644 index 0000000..cba222e --- /dev/null +++ b/epan/dissectors/packet-loop.c @@ -0,0 +1,178 @@ +/* packet-loop.c + * Routines for Ethernet loopback/Configuration Test Protocol dissection, + * as documented in section 8 "Ethernet Configuration Testing Protocol" of + * the v2.0 DIX Ethernet specification. + * + * See + * + * http://decnet.ipv7.net/docs/dundas/aa-k759b-tk.pdf + * + * for a copy of the DIX spec and + * + * http://stuff.mit.edu/people/jhawk/ctp.html + * + * for section 8. + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "config.h" + +#include <epan/packet.h> +#include <epan/etypes.h> + +void proto_register_loop(void); +void proto_reg_handoff_loop(void); + +static dissector_handle_t loop_handle; + +static int proto_loop = -1; +static int hf_loop_skipcount = -1; +static int hf_loop_function = -1; +static int hf_loop_relevant_function = -1; +static int hf_loop_receipt_number = -1; +static int hf_loop_forwarding_address = -1; + +static gint ett_loop = -1; + +#define FUNC_REPLY 1 +#define FUNC_FORWARD_DATA 2 + +static const value_string function_vals[] = { + { FUNC_REPLY, "Reply" }, + { FUNC_FORWARD_DATA, "Forward Data" }, + { 0, NULL } +}; + +static int +dissect_loop(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) +{ + proto_tree *loop_tree = NULL; + proto_item *ti; + guint16 function; + int offset = 0; + int skip_offset; + gboolean set_info = TRUE; + gboolean more_function; + tvbuff_t *next_tvb; + + col_set_str(pinfo->cinfo, COL_PROTOCOL, "LOOP"); + col_clear(pinfo->cinfo, COL_INFO); + + if (tree) { + ti = proto_tree_add_item(tree, proto_loop, tvb, offset, -1, ENC_NA); + loop_tree = proto_item_add_subtree(ti, ett_loop); + + proto_tree_add_item(loop_tree, hf_loop_skipcount, tvb, offset, 2, ENC_LITTLE_ENDIAN); + } + skip_offset = 2 + tvb_get_letohs(tvb, offset); + offset += 2; + + do { + function = tvb_get_letohs(tvb, offset); + if (offset == skip_offset) { + col_add_str(pinfo->cinfo, COL_INFO, + val_to_str(function, function_vals, "Unknown function (%u)")); + + proto_tree_add_uint(loop_tree, hf_loop_relevant_function, tvb, offset, 2, function); + set_info = FALSE; + } + proto_tree_add_uint(loop_tree, hf_loop_function, tvb, offset, 2, function); + offset += 2; + switch (function) { + + case FUNC_REPLY: + proto_tree_add_item(loop_tree, hf_loop_receipt_number, tvb, offset, 2, + ENC_LITTLE_ENDIAN); + offset += 2; + more_function = FALSE; + break; + + case FUNC_FORWARD_DATA: + proto_tree_add_item(loop_tree, hf_loop_forwarding_address, tvb, offset, + 6, ENC_NA); + offset += 6; + more_function = TRUE; + break; + + default: + more_function = FALSE; + break; + } + } while (more_function); + + if (set_info) { + col_set_str(pinfo->cinfo, COL_INFO, "No valid function found"); + } + + if (tvb_reported_length_remaining(tvb, offset) > 0) + { + next_tvb = tvb_new_subset_remaining(tvb, offset); + call_data_dissector(next_tvb, pinfo, tree); + } + return tvb_captured_length(tvb); +} + +void +proto_register_loop(void) +{ + static hf_register_info hf[] = { + { &hf_loop_skipcount, + { "skipCount", "loop.skipcount", + FT_UINT16, BASE_DEC, NULL, 0x0, + NULL, HFILL }}, + + { &hf_loop_function, + { "Function", "loop.function", + FT_UINT16, BASE_DEC, VALS(function_vals), 0x0, + NULL, HFILL }}, + + { &hf_loop_relevant_function, + { "Relevant function", "loop.relevant_function", + FT_UINT16, BASE_DEC, VALS(function_vals), 0x0, + NULL, HFILL }}, + + { &hf_loop_receipt_number, + { "Receipt number", "loop.receipt_number", + FT_UINT16, BASE_DEC, NULL, 0x0, + NULL, HFILL }}, + + { &hf_loop_forwarding_address, + { "Forwarding address", "loop.forwarding_address", + FT_ETHER, BASE_NONE, NULL, 0x0, + NULL, HFILL }}, + }; + static gint *ett[] = { + &ett_loop, + }; + + proto_loop = proto_register_protocol("Configuration Test Protocol (loopback)", + "LOOP", "loop"); + proto_register_field_array(proto_loop, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + + loop_handle = register_dissector("loop", dissect_loop, proto_loop); +} + +void +proto_reg_handoff_loop(void) +{ + dissector_add_uint("ethertype", ETHERTYPE_LOOP, loop_handle); +} + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local Variables: + * c-basic-offset: 2 + * tab-width: 8 + * indent-tabs-mode: nil + * End: + * + * ex: set shiftwidth=2 tabstop=8 expandtab: + * :indentSize=2:tabSize=8:noTabs=true: + */ |