diff options
Diffstat (limited to 'epan/dissectors/packet-laplink.c')
| -rw-r--r-- | epan/dissectors/packet-laplink.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/epan/dissectors/packet-laplink.c b/epan/dissectors/packet-laplink.c new file mode 100644 index 00000000..5ed41f91 --- /dev/null +++ b/epan/dissectors/packet-laplink.c @@ -0,0 +1,243 @@ +/* packet-laplink.c + * Routines for laplink dissection + * Copyright 2003, Brad Hards <bradh@frogmouth.net> + * + * 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 "packet-tcp.h" +#include <epan/prefs.h> + +void proto_register_laplink(void); +void proto_reg_handoff_laplink(void); + +static dissector_handle_t laplink_udp_handle; +static dissector_handle_t laplink_tcp_handle; + +#define TCP_PORT_LAPLINK 1547 +#define UDP_PORT_LAPLINK 1547 + +/* Initialize the protocol and registered fields */ +static int proto_laplink = -1; +static int hf_laplink_udp_ident = -1; +static int hf_laplink_udp_name = -1; +static int hf_laplink_tcp_ident = -1; +static int hf_laplink_tcp_length = -1; +static int hf_laplink_tcp_data = -1; + +/* Initialize the subtree pointers */ +static gint ett_laplink = -1; + +static const value_string laplink_udp_magic[] = { + { 0x0f010000, "Name Solicitation" }, + { 0xf0000200, "Name Reply" }, + { 0, NULL } +}; + +static const value_string laplink_tcp_magic[] = { + { 0xff08c000, "Unknown TCP query - connection?" }, + { 0xff08c200, "Unknown TCP query - connection?" }, + { 0xff0bc000, "Unknown TCP query - connection?" }, + { 0xff0bc200, "Unknown TCP query - connection?" }, + { 0xff10c000, "Unknown TCP response - connection?" }, + { 0xff10c200, "Unknown TCP response - connection?" }, + { 0xff11c000, "Unknown TCP query/response - directory list or file transfer?" }, + { 0xff11c200, "Unknown TCP query - directory list or file request?" }, + { 0xff13c000, "Unknown TCP response - connection?" }, + { 0xff13c200, "Unknown TCP response - connection?" }, + { 0xff14c000, "Unknown TCP response - directory list or file transfer?" }, + { 0, NULL } +}; + +static gboolean laplink_desegment = TRUE; + +/* Code to actually dissect the packets - UDP */ +static gint +dissect_laplink_udp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) +{ + int offset = 0; + proto_item *ti; + proto_tree *laplink_tree; + guint32 udp_ident; + const gchar *udp_ident_string; + + /* + * Make sure the identifier is reasonable. + */ + if (!tvb_bytes_exist(tvb, offset, 4)) + return 0; /* not enough bytes to check */ + udp_ident = tvb_get_ntohl(tvb, offset); + udp_ident_string = try_val_to_str(udp_ident, laplink_udp_magic); + if (udp_ident_string == NULL) + return 0; /* unknown */ + +/* Make entries in Protocol column and Info column on summary display */ + col_set_str(pinfo->cinfo, COL_PROTOCOL, "Laplink"); + + col_add_str(pinfo->cinfo, COL_INFO, udp_ident_string); + + if (tree){ + ti = proto_tree_add_item(tree, proto_laplink, tvb, 0, -1, ENC_NA); + laplink_tree = proto_item_add_subtree(ti, ett_laplink); + + proto_tree_add_uint(laplink_tree, hf_laplink_udp_ident, tvb, offset, 4, udp_ident); + offset += 4; + + proto_tree_add_item(laplink_tree, hf_laplink_udp_name, tvb, offset, -1, ENC_ASCII); + } + return tvb_captured_length(tvb); +} + +/* Code to actually dissect the packets - TCP aspects*/ +static int +dissect_laplink_tcp_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) +{ + int offset = 0; + int length = 0; + proto_item *ti; + proto_tree *laplink_tree; + guint32 tcp_ident; + +/* Make entries in Protocol column and Info column on summary display */ + col_set_str(pinfo->cinfo, COL_PROTOCOL, "Laplink"); + + tcp_ident = tvb_get_ntohl(tvb, offset); + col_add_str(pinfo->cinfo, COL_INFO, + val_to_str(tcp_ident, laplink_tcp_magic, "TCP TBA (%u)")); + + if (tree){ + ti = proto_tree_add_item(tree, proto_laplink, tvb, 0, -1, ENC_NA); + + + laplink_tree = proto_item_add_subtree(ti, ett_laplink); + + proto_tree_add_item(laplink_tree, hf_laplink_tcp_ident, tvb, offset, 4, ENC_BIG_ENDIAN); + offset += 4; + + length = tvb_get_ntohs(tvb, offset); + proto_tree_add_item(laplink_tree, hf_laplink_tcp_length, tvb, offset, 2, ENC_BIG_ENDIAN); + offset += 2; + + proto_tree_add_item(laplink_tree, hf_laplink_tcp_data, tvb, offset, length, ENC_NA); + +/* Continue adding tree items to process the packet here */ + + } + + return tvb_captured_length(tvb); +/* If this protocol has a sub-dissector call it here, see section 1.8 */ +} + +static guint +get_laplink_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_) +{ + guint plen; + /* + * The length doesn't include the length or ident fields; add those in. + */ + plen = (tvb_get_ntohs(tvb, offset+4) + 2 + 4); + return plen; +} + +static int +dissect_laplink_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data) +{ + tcp_dissect_pdus(tvb, pinfo, tree, laplink_desegment, + 6, get_laplink_pdu_len, + dissect_laplink_tcp_pdu, data); + return tvb_captured_length(tvb); +} + + +/* Register the protocol with Wireshark */ + +void +proto_register_laplink(void) +{ + +/* Setup list of header fields See Section 1.6.1 for details*/ + static hf_register_info hf[] = { + { &hf_laplink_udp_ident, + { "UDP Ident", "laplink.udp_ident", + FT_UINT32, BASE_HEX, VALS(laplink_udp_magic), 0x0, + "Unknown magic", HFILL } + }, + { &hf_laplink_udp_name, + { "UDP Name", "laplink.udp_name", + FT_STRINGZ, BASE_NONE, NULL, 0x0, + "Machine name", HFILL } + }, + { &hf_laplink_tcp_ident, + { "TCP Ident", "laplink.tcp_ident", + FT_UINT32, BASE_HEX, VALS(laplink_tcp_magic), 0x0, + "Unknown magic", HFILL } + }, + { &hf_laplink_tcp_length, + { "TCP Data payload length", "laplink.tcp_length", + FT_UINT16, BASE_DEC, NULL, 0x0, + "Length of remaining payload", HFILL } + }, + { &hf_laplink_tcp_data, + { "Unknown TCP data", "laplink.tcp_data", + FT_BYTES, BASE_NONE, NULL, 0x0, + "TCP data", HFILL } + }, + }; + +/* Setup protocol subtree array */ + static gint *ett[] = { + &ett_laplink, + }; + + module_t *laplink_module; + +/* Register the protocol name and description */ + proto_laplink = proto_register_protocol("Laplink", "Laplink", "laplink"); + +/* Required function calls to register the header fields and subtrees used */ + proto_register_field_array(proto_laplink, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + + laplink_module = prefs_register_protocol(proto_laplink, NULL); + prefs_register_bool_preference(laplink_module, "desegment_laplink_over_tcp", + "Reassemble Laplink over TCP messages spanning multiple TCP segments", + "Whether the Laplink dissector should reassemble messages spanning multiple TCP segments." + " To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.", + &laplink_desegment); + + laplink_tcp_handle = register_dissector("laplink.tcp", dissect_laplink_tcp, proto_laplink); + laplink_udp_handle = register_dissector("laplink.udp", dissect_laplink_udp, proto_laplink); +} + + +/* If this dissector uses sub-dissector registration add a registration routine. + This format is required because a script is used to find these routines and + create the code that calls these routines. +*/ +void +proto_reg_handoff_laplink(void) +{ + dissector_add_uint_with_preference("tcp.port", TCP_PORT_LAPLINK, laplink_tcp_handle); + dissector_add_uint_with_preference("udp.port", UDP_PORT_LAPLINK, laplink_udp_handle); +} + +/* + * 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: + */ |