forked from osmocom/wireshark
![Guy Harris](/assets/img/avatar_default.png)
Bug: 13125 Change-Id: Ib5d02e8841eb7e4d04e6a1df44a5eba5b925ce6c Reviewed-on: https://code.wireshark.org/review/18749 Reviewed-by: Guy Harris <guy@alum.mit.edu>
250 lines
7.3 KiB
C
250 lines
7.3 KiB
C
/* packet-gdb.c
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* Routines for dissection of GDB's Remote Serial Protocol
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*
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* Copyright 2014, Martin Kaiser <martin@kaiser.cx>
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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 modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (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 along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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/*
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* The GDB Remote Serial Protocol is used between an instance of the
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* GNU Debugger and a remote target such as an embedded system.
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* It can be run over TCP/IP or a serial line, we support only TCP/IP.
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*
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* The protocol specification is in Annex E of the GDB user manual
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* http://www.gnu.org/software/gdb/documentation/
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*
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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/tvbparse.h>
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enum {
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GDB_TOK_ACK,
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GDB_TOK_START,
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GDB_TOK_PAYLOAD,
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GDB_TOK_END,
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GDB_TOK_CHKSUM
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};
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static const value_string gdb_ack[] = {
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{ '+', "Transmission successful" },
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{ '-', "Transmission failed" },
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{ 0, NULL }
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};
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void proto_register_gdb(void);
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void proto_reg_handoff_gdb(void);
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static int proto_gdb = -1;
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static gint ett_gdb = -1;
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static int hf_gdb_ack = -1;
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static int hf_gdb_start = -1;
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static int hf_gdb_payload = -1;
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static int hf_gdb_end = -1;
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static int hf_gdb_chksum = -1;
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static tvbparse_wanted_t *want;
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static void
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dissect_gdb_token(void *tvbparse_data, const void *wanted_data, tvbparse_elem_t *tok)
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{
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proto_tree *tree;
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guint token;
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if (!tok) /* XXX - is this check necessary? */
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return;
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tree = (proto_tree *)tvbparse_data;
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token = GPOINTER_TO_UINT(wanted_data);
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/* XXX - check that tok->len is what we expect? */
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switch (token) {
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case GDB_TOK_ACK:
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proto_tree_add_item(tree, hf_gdb_ack,
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tok->tvb, tok->offset, tok->len, ENC_ASCII|ENC_NA);
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break;
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case GDB_TOK_START:
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proto_tree_add_item(tree, hf_gdb_start,
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tok->tvb, tok->offset, tok->len, ENC_ASCII|ENC_NA);
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break;
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case GDB_TOK_PAYLOAD:
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proto_tree_add_item(tree, hf_gdb_payload,
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tok->tvb, tok->offset, tok->len, ENC_NA);
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break;
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case GDB_TOK_END:
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proto_tree_add_item(tree, hf_gdb_end,
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tok->tvb, tok->offset, tok->len, ENC_ASCII|ENC_NA);
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break;
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case GDB_TOK_CHKSUM:
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proto_tree_add_item(tree, hf_gdb_chksum,
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tok->tvb, tok->offset, tok->len, ENC_ASCII|ENC_NA);
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break;
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default:
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break;
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}
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}
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static void init_gdb_parser(void) {
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tvbparse_wanted_t *want_ack;
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tvbparse_wanted_t *want_start;
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tvbparse_wanted_t *want_payload;
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tvbparse_wanted_t *want_end;
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tvbparse_wanted_t *want_chksum;
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want_ack = tvbparse_chars(-1, 1, 1, "+-",
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GUINT_TO_POINTER(GDB_TOK_ACK), NULL, dissect_gdb_token);
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want_start = tvbparse_chars(-1, 1, 1, "$",
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GUINT_TO_POINTER(GDB_TOK_START), NULL, dissect_gdb_token);
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want_payload = tvbparse_not_chars(-1, 1, 0, "$#",
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GUINT_TO_POINTER(GDB_TOK_PAYLOAD), NULL, dissect_gdb_token);
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want_end = tvbparse_chars(-1, 1, 1, "#",
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GUINT_TO_POINTER(GDB_TOK_END), NULL, dissect_gdb_token);
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want_chksum = tvbparse_chars(-1, 2, 2, "0123456789abcdefABCDEF",
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GUINT_TO_POINTER(GDB_TOK_CHKSUM), NULL, dissect_gdb_token);
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want = tvbparse_set_seq(-1, NULL, NULL, NULL,
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tvbparse_some(-1, 0, 1, NULL, NULL, NULL, want_ack),
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want_start, want_payload, want_end, want_chksum, NULL);
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}
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static void
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dissect_gdb_packet(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_item *ti;
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proto_tree *gdb_tree;
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tvbparse_t *tt;
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "GDB");
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col_clear(pinfo->cinfo, COL_INFO);
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ti = proto_tree_add_protocol_format(tree, proto_gdb,
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tvb, 0, tvb_reported_length(tvb), "GDB Remote Serial Protocol");
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gdb_tree = proto_item_add_subtree(ti, ett_gdb);
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/* XXX support multiple sub-trees */
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tt = tvbparse_init(tvb, 0, -1, (void *)gdb_tree, NULL);
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while(tvbparse_get(tt, want)) {
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;
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}
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}
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static int
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dissect_gdb_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
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{
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gint offset=0, offset_start;
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gint pos;
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guint packet_len;
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tvbuff_t *packet_tvb;
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while (tvb_captured_length_remaining(tvb, offset) > 0) {
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packet_tvb = NULL;
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offset_start = offset;
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pos = tvb_find_guint8(tvb, offset, -1, '#');
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if (pos != -1) {
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offset += pos;
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offset++; /* skip the hash sign */
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/* to have a complete packet, we need another two bytes
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for the checksum */
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if (tvb_bytes_exist(tvb, offset, 2)) {
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offset += 2;
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packet_len = offset-offset_start;
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packet_tvb = tvb_new_subset_length(tvb, offset_start,
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packet_len);
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}
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}
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if (packet_tvb)
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dissect_gdb_packet(tvb, pinfo, tree);
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else {
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pinfo->desegment_offset = offset;
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pinfo->desegment_len = DESEGMENT_ONE_MORE_SEGMENT;
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return tvb_captured_length(tvb);
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}
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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_gdb(void)
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{
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static hf_register_info hf[] = {
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{ &hf_gdb_ack,
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{ "Acknowledge", "gdb.ack", FT_CHAR, BASE_HEX,
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VALS(gdb_ack), 0, NULL, HFILL } },
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{ &hf_gdb_start,
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{ "Start character", "gdb.start", FT_STRING, BASE_NONE,
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NULL, 0, NULL, HFILL } },
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{ &hf_gdb_payload,
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{ "Payload", "gdb.payload", FT_BYTES, BASE_NONE,
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NULL, 0, NULL, HFILL } },
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{ &hf_gdb_end,
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{ "Terminating character", "gdb.end", FT_STRING, BASE_NONE,
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NULL, 0, NULL, HFILL } },
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{ &hf_gdb_chksum,
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{ "Checksum", "gdb.chksum", FT_STRING, BASE_NONE,
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NULL, 0, NULL, HFILL } }
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};
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static gint *ett[] = {
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&ett_gdb
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};
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proto_gdb = proto_register_protocol("GDB Remote Serial Protocol", "GDB remote", "gdb");
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proto_register_field_array(proto_gdb, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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init_gdb_parser();
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}
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void
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proto_reg_handoff_gdb(void)
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{
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dissector_handle_t gdb_handle;
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gdb_handle = create_dissector_handle(dissect_gdb_tcp, proto_gdb);
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dissector_add_for_decode_as_with_preference("tcp.port", gdb_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: 4
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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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* vi: set shiftwidth=4 tabstop=8 expandtab:
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* :indentSize=4:tabSize=8:noTabs=true:
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*/
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