forked from osmocom/wireshark
795 lines
27 KiB
C
795 lines
27 KiB
C
/* packet-dnp3.c
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* Routines for DNP dissection
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* Copyright 2003, Graham Bloice <graham.bloice@trihedral.com>
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*
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* $Id$
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@ethereal.com>
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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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <math.h>
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#include <glib.h>
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#ifdef NEED_SNPRINTF_H
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# include "snprintf.h"
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#endif
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#include <epan/packet.h>
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#include <epan/prefs.h>
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#include <epan/reassemble.h>
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/*
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* See
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*
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* http://www.dnp.org/
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*
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* although note that you have to join the DNP organization to get to
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* see the protocol specs online - otherwise, you have to buy a
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* dead-tree version.
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*/
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/* DNP 3.0 constants */
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#define DNP_HDR_LEN 10
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#define TCP_PORT_DNP 20000
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#define DNP3_CTL_DIR 0x80
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#define DNP3_CTL_PRM 0x40
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#define DNP3_CTL_FCB 0x20
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#define DNP3_CTL_FCV 0x10
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#define DNP3_CTL_RES 0x20
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#define DNP3_CTL_DFC 0x10
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#define DNP3_CTL_FUNC 0x0f
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#define DNP3_DL_LEN_OFFS 0x02
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#define DNP3_DL_CTL_OFFS 0x03
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#define DNP3_DL_DST_OFFS 0x04
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#define DNP3_DL_SRC_OFFS 0x06
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#define DNP3_TR_FIR 0x40
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#define DNP3_TR_FIN 0x80
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#define DNP3_TR_SEQ 0x3f
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#define AL_MAX_CHUNK_SIZE 16
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#define DNP3_AL_CON 0x20
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#define DNP3_AL_FIN 0x40
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#define DNP3_AL_FIR 0x80
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#define DNP3_AL_SEQ 0x1f
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#define DNP3_AL_FUNC 0xff
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#define DNP3_AL_CTL_OFFS 0x0
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#define DNP3_AL_FUNC_OFFS 0x1
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/* DL Function codes */
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#define DL_FUNC_RESET_LINK 0x0
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#define DL_FUNC_RESET_PROC 0x1
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#define DL_FUNC_TEST_LINK 0x2
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#define DL_FUNC_USER_DATA 0x3
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#define DL_FUNC_UNC_DATA 0x4
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#define DL_FUNC_LINK_STAT 0x9
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#define DL_FUNC_ACK 0x0
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#define DL_FUNC_NACK 0x1
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#define DL_FUNC_STAT_LINK 0xB
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#define DL_FUNC_NO_FUNC 0xE
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#define DL_FUNC_NOT_IMPL 0xF
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/* AL Function codes */
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#define DL_AL_FUNC_CONFIRM 0x0
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#define DL_AL_FUNC_READ 0x01
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#define DL_AL_FUNC_WRITE 0x02
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#define DL_AL_FUNC_DIROP 0x05
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#define DL_AL_FUNC_RESPON 0x81
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/* Initialize the protocol and registered fields */
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static int proto_dnp3 = -1;
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static int hf_dnp3_start = -1;
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static int hf_dnp3_len = -1;
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static int hf_dnp3_ctl = -1;
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static int hf_dnp3_ctl_prifunc = -1;
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static int hf_dnp3_ctl_secfunc = -1;
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static int hf_dnp3_ctl_dir = -1;
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static int hf_dnp3_ctl_prm = -1;
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static int hf_dnp3_ctl_fcb = -1;
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static int hf_dnp3_ctl_fcv = -1;
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static int hf_dnp3_ctl_dfc = -1;
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static int hf_dnp3_dst = -1;
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static int hf_dnp3_src = -1;
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static int hf_dnp_hdr_CRC = -1;
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static int hf_dnp_hdr_CRC_bad = -1;
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static int hf_dnp3_tr_ctl = -1;
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static int hf_dnp3_tr_fin = -1;
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static int hf_dnp3_tr_fir = -1;
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static int hf_dnp3_tr_seq = -1;
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static int hf_dnp3_al_ctl = -1;
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static int hf_dnp3_al_fir = -1;
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static int hf_dnp3_al_fin = -1;
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static int hf_dnp3_al_con = -1;
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static int hf_dnp3_al_seq = -1;
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static int hf_dnp3_al_func = -1;
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/* ************************************************************************* */
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/* Header values for reassembly */
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/* ************************************************************************* */
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static int hf_fragments = -1;
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static int hf_fragment = -1;
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static int hf_fragment_overlap = -1;
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static int hf_fragment_overlap_conflict = -1;
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static int hf_fragment_multiple_tails = -1;
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static int hf_fragment_too_long_fragment = -1;
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static int hf_fragment_error = -1;
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static int hf_fragment_reassembled_in = -1;
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/* Control Function Code Values */
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static const value_string dnp3_ctl_func_pri_vals[] = {
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{ DL_FUNC_RESET_LINK, "Reset of remote link" },
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{ DL_FUNC_RESET_PROC, "Reset of user process" },
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{ DL_FUNC_TEST_LINK, "Test function for link" },
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{ DL_FUNC_USER_DATA, "User Data" },
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{ DL_FUNC_UNC_DATA, "Unconfirmed User Data" },
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{ DL_FUNC_LINK_STAT, "Request Link Status" },
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{ 0, NULL }
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};
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static const value_string dnp3_ctl_func_sec_vals[] = {
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{ DL_FUNC_ACK, "ACK" },
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{ DL_FUNC_NACK, "NACK" },
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{ DL_FUNC_STAT_LINK, "Status of Link" },
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{ DL_FUNC_NO_FUNC, "Link service not functioning" },
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{ DL_FUNC_NOT_IMPL, "Link service not used or implemented" },
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{ 0, NULL }
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};
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static const value_string dnp3_ctl_flags_pri_vals[] = {
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{ DNP3_CTL_DIR, "DIR" },
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{ DNP3_CTL_PRM, "PRM" },
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{ DNP3_CTL_FCB, "FCB" },
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{ DNP3_CTL_FCV, "FCV" },
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{ 0, NULL }
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};
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static const value_string dnp3_ctl_flags_sec_vals[] = {
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{ DNP3_CTL_DIR, "DIR" },
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{ DNP3_CTL_PRM, "PRM" },
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{ DNP3_CTL_RES, "RES" },
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{ DNP3_CTL_DFC, "DFC" },
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{ 0, NULL }
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};
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static const value_string dnp3_tr_flags_vals[] = {
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{ DNP3_TR_FIN, "FIN" },
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{ DNP3_TR_FIR, "FIR" },
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{ 0, NULL }
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};
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static const value_string dnp3_al_flags_vals[] = {
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{ DNP3_AL_FIR, "FIR" },
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{ DNP3_AL_FIN, "FIN" },
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{ DNP3_AL_CON, "CON" },
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{ 0, NULL }
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};
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/* Control Function Code Values */
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static const value_string dnp3_al_func_vals[] = {
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{ DL_AL_FUNC_CONFIRM, "Confirm" },
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{ DL_AL_FUNC_READ, "Read" },
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{ DL_AL_FUNC_WRITE, "Write" },
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{ DL_AL_FUNC_DIROP, "Direct Operate" },
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{ DL_AL_FUNC_RESPON, "Response" },
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{ 0, NULL }
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};
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/* Initialize the subtree pointers */
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static gint ett_dnp3 = -1;
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static gint ett_dnp3_dl = -1;
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static gint ett_dnp3_dl_ctl = -1;
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static gint ett_dnp3_tr_ctl = -1;
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static gint ett_dnp3_al_data = -1;
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static gint ett_dnp3_al = -1;
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static gint ett_dnp3_al_ctl = -1;
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static gint ett_fragment = -1;
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static gint ett_fragments = -1;
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/* Tables for reassembly of fragments. */
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static GHashTable *al_fragment_table = NULL;
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static GHashTable *al_reassembled_table = NULL;
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static const fragment_items frag_items = {
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&ett_fragment,
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&ett_fragments,
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&hf_fragments,
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&hf_fragment,
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&hf_fragment_overlap,
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&hf_fragment_overlap_conflict,
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&hf_fragment_multiple_tails,
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&hf_fragment_too_long_fragment,
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&hf_fragment_error,
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&hf_fragment_reassembled_in,
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"fragments"
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};
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/*****************************************************************/
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/* */
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/* CRC LOOKUP TABLE */
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/* ================ */
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/* The following CRC lookup table was generated automagically */
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/* by the Rocksoft^tm Model CRC Algorithm Table Generation */
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/* Program V1.0 using the following model parameters: */
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/* */
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/* Width : 2 bytes. */
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/* Poly : 0x3D65 */
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/* Reverse : TRUE. */
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/* */
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/* For more information on the Rocksoft^tm Model CRC Algorithm, */
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/* see the document titled "A Painless Guide to CRC Error */
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/* Detection Algorithms" by Ross Williams */
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/* (ross@guest.adelaide.edu.au.). This document is likely to be */
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/* in the FTP archive "ftp.adelaide.edu.au/pub/rocksoft". */
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/* */
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/*****************************************************************/
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static guint16 crctable[256] =
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{
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0x0000, 0x365E, 0x6CBC, 0x5AE2, 0xD978, 0xEF26, 0xB5C4, 0x839A,
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0xFF89, 0xC9D7, 0x9335, 0xA56B, 0x26F1, 0x10AF, 0x4A4D, 0x7C13,
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0xB26B, 0x8435, 0xDED7, 0xE889, 0x6B13, 0x5D4D, 0x07AF, 0x31F1,
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0x4DE2, 0x7BBC, 0x215E, 0x1700, 0x949A, 0xA2C4, 0xF826, 0xCE78,
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0x29AF, 0x1FF1, 0x4513, 0x734D, 0xF0D7, 0xC689, 0x9C6B, 0xAA35,
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0xD626, 0xE078, 0xBA9A, 0x8CC4, 0x0F5E, 0x3900, 0x63E2, 0x55BC,
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0x9BC4, 0xAD9A, 0xF778, 0xC126, 0x42BC, 0x74E2, 0x2E00, 0x185E,
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0x644D, 0x5213, 0x08F1, 0x3EAF, 0xBD35, 0x8B6B, 0xD189, 0xE7D7,
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0x535E, 0x6500, 0x3FE2, 0x09BC, 0x8A26, 0xBC78, 0xE69A, 0xD0C4,
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0xACD7, 0x9A89, 0xC06B, 0xF635, 0x75AF, 0x43F1, 0x1913, 0x2F4D,
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0xE135, 0xD76B, 0x8D89, 0xBBD7, 0x384D, 0x0E13, 0x54F1, 0x62AF,
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0x1EBC, 0x28E2, 0x7200, 0x445E, 0xC7C4, 0xF19A, 0xAB78, 0x9D26,
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0x7AF1, 0x4CAF, 0x164D, 0x2013, 0xA389, 0x95D7, 0xCF35, 0xF96B,
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0x8578, 0xB326, 0xE9C4, 0xDF9A, 0x5C00, 0x6A5E, 0x30BC, 0x06E2,
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0xC89A, 0xFEC4, 0xA426, 0x9278, 0x11E2, 0x27BC, 0x7D5E, 0x4B00,
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0x3713, 0x014D, 0x5BAF, 0x6DF1, 0xEE6B, 0xD835, 0x82D7, 0xB489,
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0xA6BC, 0x90E2, 0xCA00, 0xFC5E, 0x7FC4, 0x499A, 0x1378, 0x2526,
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0x5935, 0x6F6B, 0x3589, 0x03D7, 0x804D, 0xB613, 0xECF1, 0xDAAF,
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0x14D7, 0x2289, 0x786B, 0x4E35, 0xCDAF, 0xFBF1, 0xA113, 0x974D,
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0xEB5E, 0xDD00, 0x87E2, 0xB1BC, 0x3226, 0x0478, 0x5E9A, 0x68C4,
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0x8F13, 0xB94D, 0xE3AF, 0xD5F1, 0x566B, 0x6035, 0x3AD7, 0x0C89,
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0x709A, 0x46C4, 0x1C26, 0x2A78, 0xA9E2, 0x9FBC, 0xC55E, 0xF300,
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0x3D78, 0x0B26, 0x51C4, 0x679A, 0xE400, 0xD25E, 0x88BC, 0xBEE2,
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0xC2F1, 0xF4AF, 0xAE4D, 0x9813, 0x1B89, 0x2DD7, 0x7735, 0x416B,
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0xF5E2, 0xC3BC, 0x995E, 0xAF00, 0x2C9A, 0x1AC4, 0x4026, 0x7678,
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0x0A6B, 0x3C35, 0x66D7, 0x5089, 0xD313, 0xE54D, 0xBFAF, 0x89F1,
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0x4789, 0x71D7, 0x2B35, 0x1D6B, 0x9EF1, 0xA8AF, 0xF24D, 0xC413,
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0xB800, 0x8E5E, 0xD4BC, 0xE2E2, 0x6178, 0x5726, 0x0DC4, 0x3B9A,
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0xDC4D, 0xEA13, 0xB0F1, 0x86AF, 0x0535, 0x336B, 0x6989, 0x5FD7,
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0x23C4, 0x159A, 0x4F78, 0x7926, 0xFABC, 0xCCE2, 0x9600, 0xA05E,
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0x6E26, 0x5878, 0x029A, 0x34C4, 0xB75E, 0x8100, 0xDBE2, 0xEDBC,
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0x91AF, 0xA7F1, 0xFD13, 0xCB4D, 0x48D7, 0x7E89, 0x246B, 0x1235
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};
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/*****************************************************************/
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/* End of CRC Lookup Table */
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/*****************************************************************/
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/* calculates crc given a buffer of characters and a length of buffer */
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static guint16
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calculateCRC(const void *buf, guint len) {
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guint16 crc = 0;
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const guint8 *p = (const guint8 *)buf;
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while(len-- > 0)
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crc = crctable[(crc ^ *p++) & 0xff] ^ (crc >> 8);
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return ~crc;
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}
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/* function to print list of bit flags */
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static guint
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flags_to_str(guint8 val, const value_string *vs, gchar *const str)
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{
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guint i, fpos;
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i = fpos = 0;
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while (vs[i].strptr) {
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if (val & vs[i].value) {
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if (fpos) {
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strcpy(&str[fpos], ", ");
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fpos += 2;
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}
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strcpy(&str[fpos], vs[i].strptr);
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fpos += strlen(vs[i].strptr);
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}
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i++;
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}
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return fpos;
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}
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/* Code to actually dissect the packets */
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/* Application layer dissector */
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static void
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dissect_dnp3_al(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
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{
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guint8 al_ctl, al_seq, al_func;
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gboolean al_fir, al_fin, al_con;
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gchar flags[64] = "<None>";
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guint fpos = 0;
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int offset = 0;
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proto_item *ti = NULL, *tc;
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proto_tree *al_tree = NULL, *field_tree = NULL;
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const gchar *func_code_str;
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/* Handle the control byte and function code */
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al_ctl = tvb_get_guint8(tvb, DNP3_AL_CTL_OFFS);
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al_seq = al_ctl & DNP3_AL_SEQ;
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al_fir = al_ctl & DNP3_AL_FIR;
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al_fin = al_ctl & DNP3_AL_FIN;
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al_con = al_ctl & DNP3_AL_CON;
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al_func = tvb_get_guint8(tvb, DNP3_AL_FUNC_OFFS);
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func_code_str = val_to_str(al_func, dnp3_al_func_vals, "Unknown function (0x%02x)");
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if (tree) {
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/* format up the text representation */
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fpos = flags_to_str(al_ctl, dnp3_al_flags_vals, flags);
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if (fpos) {
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strcpy(&flags[fpos], ", ");
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fpos += 2;
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}
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flags[fpos] = '\0';
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/* Add the al tree branch */
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ti = proto_tree_add_text(tree, tvb, offset, -1,
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"Application Layer: (%sSequence %d, %s)",
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flags, al_seq, func_code_str);
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al_tree = proto_item_add_subtree(ti, ett_dnp3_al);
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/* al control byte subtree */
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tc = proto_tree_add_uint_format(al_tree, hf_dnp3_al_ctl, tvb, offset, 1, al_ctl,
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"Control: 0x%02x (%sSequence %d)", al_ctl, flags, al_seq);
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field_tree = proto_item_add_subtree(tc, ett_dnp3_al_ctl);
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proto_tree_add_boolean(field_tree, hf_dnp3_al_fir, tvb, offset, 1, al_ctl);
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proto_tree_add_boolean(field_tree, hf_dnp3_al_fin, tvb, offset, 1, al_ctl);
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proto_tree_add_boolean(field_tree, hf_dnp3_al_con, tvb, offset, 1, al_ctl);
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proto_tree_add_item(field_tree, hf_dnp3_al_seq, tvb, offset, 1, al_ctl);
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offset += 1;
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/* AL function code byte */
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proto_tree_add_uint_format(al_tree, hf_dnp3_al_func, tvb, offset, 1, al_func,
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"Function Code: %s (0x%02x)", func_code_str, al_func);
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offset += 1;
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}
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else
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offset += 2; /* No tree, correct offset */
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}
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/* Data Link and Transport layer dissector */
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static void
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dissect_dnp3(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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/* Set up structures needed to add the protocol subtree and manage it */
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proto_item *ti = NULL, *tdl, *tc, *al_chunks;
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proto_tree *dnp3_tree = NULL, *dl_tree = NULL, *tr_tree = NULL, *field_tree = NULL, *al_tree = NULL, *frag_tree_item;
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int offset = 0;
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gboolean dl_prm, tr_fir, tr_fin;
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guint8 dl_len, dl_ctl, dl_func, tr_ctl, tr_seq;
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guint fpos = 0;
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gchar flags[64] = "<None>";
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const gchar *func_code_str;
|
|
guint16 dl_dst, dl_src, dl_crc, calc_dl_crc;
|
|
guint8 *tmp = NULL, *tmp_ptr;
|
|
guint8 data_len;
|
|
int data_offset;
|
|
gboolean crc_OK = FALSE;
|
|
tvbuff_t *al_tvb = NULL;
|
|
guint i;
|
|
static guint seq_number = 0;
|
|
|
|
/* Make entries in Protocol column and Info column on summary display */
|
|
if (check_col(pinfo->cinfo, COL_PROTOCOL))
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DNP 3.0");
|
|
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
|
|
dl_len = tvb_get_guint8(tvb, DNP3_DL_LEN_OFFS);
|
|
dl_ctl = tvb_get_guint8(tvb, DNP3_DL_CTL_OFFS);
|
|
dl_dst = tvb_get_letohs(tvb, DNP3_DL_DST_OFFS);
|
|
dl_src = tvb_get_letohs(tvb, DNP3_DL_SRC_OFFS);
|
|
dl_func = dl_ctl & DNP3_CTL_FUNC;
|
|
dl_prm = dl_ctl & DNP3_CTL_PRM;
|
|
func_code_str = val_to_str(dl_func, dl_prm ? dnp3_ctl_func_pri_vals : dnp3_ctl_func_sec_vals,
|
|
"Unknown function (0x%02x)");
|
|
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, "len=%d, from %d to %d, %s",
|
|
dl_len, dl_src, dl_dst, func_code_str);
|
|
|
|
if (tree) {
|
|
|
|
/* create display subtree for the protocol */
|
|
ti = proto_tree_add_item(tree, proto_dnp3, tvb, offset, -1, FALSE);
|
|
dnp3_tree = proto_item_add_subtree(ti, ett_dnp3);
|
|
|
|
/* format up the text representation of the flags and function code */
|
|
fpos = flags_to_str(dl_ctl, dl_prm ? dnp3_ctl_flags_pri_vals : dnp3_ctl_flags_sec_vals, flags);
|
|
if (fpos) {
|
|
strcpy(&flags[fpos], ", ");
|
|
fpos += 2;
|
|
}
|
|
strcpy(&flags[fpos], func_code_str);
|
|
fpos += strlen(func_code_str);
|
|
flags[fpos] = '\0';
|
|
|
|
/* create subtree for data link layer */
|
|
tdl = proto_tree_add_text(dnp3_tree, tvb, offset, DNP_HDR_LEN,
|
|
"Data Link Layer, Len: %d, From: %d, To: %d, %s",
|
|
dl_len, dl_src, dl_dst, flags);
|
|
dl_tree = proto_item_add_subtree(tdl, ett_dnp3_dl);
|
|
|
|
/* start bytes */
|
|
proto_tree_add_item(dl_tree, hf_dnp3_start, tvb, offset, 2, FALSE);
|
|
offset += 2;
|
|
|
|
/* add length field */
|
|
proto_tree_add_item(dl_tree, hf_dnp3_len, tvb, offset, 1, FALSE);
|
|
offset += 1;
|
|
|
|
/* add control byte subtree */
|
|
tc = proto_tree_add_uint_format(dl_tree, hf_dnp3_ctl, tvb, offset, 1, dl_ctl,
|
|
"Control: 0x%02x (%s)", dl_ctl, flags);
|
|
field_tree = proto_item_add_subtree(tc, ett_dnp3_dl_ctl);
|
|
|
|
if (dl_prm) {
|
|
proto_tree_add_boolean(field_tree, hf_dnp3_ctl_dir, tvb, offset, 1, dl_ctl);
|
|
proto_tree_add_boolean(field_tree, hf_dnp3_ctl_prm, tvb, offset, 1, dl_ctl);
|
|
proto_tree_add_boolean(field_tree, hf_dnp3_ctl_fcb, tvb, offset, 1, dl_ctl);
|
|
proto_tree_add_boolean(field_tree, hf_dnp3_ctl_fcv, tvb, offset, 1, dl_ctl);
|
|
proto_tree_add_item(field_tree, hf_dnp3_ctl_prifunc, tvb, offset, 1, FALSE);
|
|
}
|
|
else {
|
|
proto_tree_add_boolean(field_tree, hf_dnp3_ctl_dir, tvb, offset, 1, dl_ctl);
|
|
proto_tree_add_boolean(field_tree, hf_dnp3_ctl_prm, tvb, offset, 1, dl_ctl);
|
|
proto_tree_add_boolean(field_tree, hf_dnp3_ctl_dfc, tvb, offset, 1, dl_ctl);
|
|
proto_tree_add_item(field_tree, hf_dnp3_ctl_secfunc, tvb, offset, 1, FALSE);
|
|
}
|
|
offset += 1;
|
|
|
|
/* add destination and source addresses */
|
|
proto_tree_add_item(dl_tree, hf_dnp3_dst, tvb, offset, 2, TRUE);
|
|
offset += 2;
|
|
proto_tree_add_item(dl_tree, hf_dnp3_src, tvb, offset, 2, TRUE);
|
|
offset += 2;
|
|
|
|
/* and header CRC */
|
|
dl_crc = tvb_get_letohs(tvb, offset);
|
|
calc_dl_crc = calculateCRC(tvb_get_ptr(tvb, 0, DNP_HDR_LEN - 2), DNP_HDR_LEN - 2);
|
|
if (dl_crc == calc_dl_crc)
|
|
proto_tree_add_uint_format(dl_tree, hf_dnp_hdr_CRC, tvb, offset, 2,
|
|
dl_crc, "CRC: 0x%04x (correct)", dl_crc);
|
|
else {
|
|
proto_tree_add_boolean_hidden(dl_tree, hf_dnp_hdr_CRC_bad, tvb,
|
|
offset, 2, TRUE);
|
|
proto_tree_add_uint_format(dl_tree, hf_dnp_hdr_CRC, tvb,
|
|
offset, 2, dl_crc, "CRC: 0x%04x (incorrect, should be 0x%04x)",
|
|
dl_crc, calc_dl_crc);
|
|
}
|
|
offset += 2;
|
|
}
|
|
else
|
|
offset += 10; /* No tree so correct offset */
|
|
|
|
/* get the transport layer byte */
|
|
tr_ctl = tvb_get_guint8(tvb, offset);
|
|
tr_seq = tr_ctl & DNP3_TR_SEQ;
|
|
tr_fir = tr_ctl & DNP3_TR_FIR;
|
|
tr_fin = tr_ctl & DNP3_TR_FIN;
|
|
|
|
if (tree) {
|
|
/* format up the text representation */
|
|
strcpy(flags, "<NONE>");
|
|
|
|
fpos = flags_to_str(tr_ctl, dnp3_tr_flags_vals, flags);
|
|
if (fpos) {
|
|
strcpy(&flags[fpos], ", ");
|
|
fpos += 2;
|
|
}
|
|
flags[fpos] = '\0';
|
|
|
|
tc = proto_tree_add_uint_format(dnp3_tree, hf_dnp3_tr_ctl, tvb, offset, 1, tr_ctl,
|
|
"Transport Layer: 0x%02x (%sSequence %d)", tr_ctl, flags, tr_seq);
|
|
tr_tree = proto_item_add_subtree(tc, ett_dnp3_tr_ctl);
|
|
proto_tree_add_boolean(tr_tree, hf_dnp3_tr_fin, tvb, offset, 1, tr_ctl);
|
|
proto_tree_add_boolean(tr_tree, hf_dnp3_tr_fir, tvb, offset, 1, tr_ctl);
|
|
proto_tree_add_item(tr_tree, hf_dnp3_tr_seq, tvb, offset, 1, tr_ctl);
|
|
}
|
|
|
|
/* Allocate AL chunk tree */
|
|
if (tree != NULL) {
|
|
al_chunks = proto_tree_add_text(tr_tree, tvb, offset + 1, -1, "Application data chunks");
|
|
al_tree = proto_item_add_subtree(al_chunks, ett_dnp3_al_data);
|
|
}
|
|
|
|
/* extract the application layer data, validating the CRCs */
|
|
|
|
/* XXX - check for dl_len <= 5 */
|
|
data_len = dl_len - 5; /* XXX - dl_len - 6, as we're no longer including the transport layer byte? */
|
|
tmp = g_malloc(data_len);
|
|
tmp_ptr = tmp;
|
|
i = 0;
|
|
data_offset = 1; /* skip the transport layer byte when assembling chunks */
|
|
while(data_len > 0) {
|
|
guint8 chk_size;
|
|
const guint8 *chk_ptr;
|
|
guint16 calc_crc, act_crc;
|
|
|
|
chk_size = MIN(data_len, AL_MAX_CHUNK_SIZE);
|
|
chk_ptr = tvb_get_ptr(tvb, offset, chk_size);
|
|
memcpy(tmp_ptr, chk_ptr + data_offset, chk_size - data_offset);
|
|
calc_crc = calculateCRC(chk_ptr, chk_size);
|
|
offset += chk_size;
|
|
tmp_ptr += chk_size - data_offset;
|
|
act_crc = tvb_get_letohs(tvb, offset);
|
|
offset += 2;
|
|
crc_OK = calc_crc == act_crc;
|
|
if (crc_OK)
|
|
{
|
|
if (tree)
|
|
proto_tree_add_text(al_tree, tvb, offset - (chk_size + 2), chk_size,
|
|
"Application Chunk %d Len: %d CRC 0x%04x",
|
|
i, chk_size, act_crc);
|
|
data_len -= chk_size;
|
|
}
|
|
else
|
|
{
|
|
if (tree)
|
|
proto_tree_add_text(al_tree, tvb, offset - (chk_size + 2), chk_size,
|
|
"Application Chunk %d Len: %d Bad CRC got 0x%04x expected 0x%04x",
|
|
i, chk_size, act_crc, calc_crc);
|
|
data_len = 0;
|
|
break;
|
|
}
|
|
i++;
|
|
data_offset = 0; /* copy all of the rest of the chunks */
|
|
}
|
|
|
|
/* if all crc OK, set up new tvb */
|
|
if (crc_OK) {
|
|
al_tvb = tvb_new_real_data(tmp, tmp_ptr-tmp, tmp_ptr-tmp);
|
|
tvb_set_free_cb(al_tvb, g_free);
|
|
tvb_set_child_real_data_tvbuff(tvb, al_tvb);
|
|
|
|
/* Check for fragmented packet */
|
|
if (! (tr_fir && tr_fin)) {
|
|
/* A fragmented packet */
|
|
|
|
fragment_data *fd_head;
|
|
|
|
/* if first fragment, update sequence id */
|
|
if (tr_fir) seq_number++;
|
|
|
|
/*
|
|
* If we've already seen this frame, look it up in the
|
|
* table of reassembled packets, otherwise add it to
|
|
* whatever reassembly is in progress, if any, and see
|
|
* if it's done.
|
|
*/
|
|
fd_head = fragment_add_seq_check(al_tvb, 0, pinfo, seq_number,
|
|
al_fragment_table,
|
|
al_reassembled_table,
|
|
tr_seq,
|
|
tvb_reported_length(al_tvb),
|
|
!tr_fin);
|
|
if (fd_head != NULL) {
|
|
/* We have the complete payload */
|
|
al_tvb = tvb_new_real_data(fd_head->data, fd_head->len, fd_head->len);
|
|
tvb_set_child_real_data_tvbuff(tvb, al_tvb);
|
|
add_new_data_source(pinfo, al_tvb, "Reassembled DNP 3.0 Application Layer message");
|
|
|
|
if (tree)
|
|
/* Show all fragments. */
|
|
show_fragment_seq_tree(fd_head, &frag_items, tr_tree, pinfo, al_tvb, &frag_tree_item);
|
|
}
|
|
else {
|
|
/* We don't have the complete reassembled payload. */
|
|
al_tvb = NULL;
|
|
if (check_col (pinfo->cinfo, COL_INFO))
|
|
col_append_str (pinfo->cinfo, COL_INFO,
|
|
" (Application Layer Message unreassembled)");
|
|
}
|
|
}
|
|
else {
|
|
/* No reassembly required */
|
|
add_new_data_source(pinfo, al_tvb, "DNP 3.0 Application Layer message");
|
|
}
|
|
}
|
|
else {
|
|
/* CRC error - throw away the data. */
|
|
g_free(tmp);
|
|
if (tree)
|
|
proto_tree_add_text(dnp3_tree, tvb, 11, -1,
|
|
"CRC failed, %d chunks", i);
|
|
}
|
|
|
|
if (al_tvb)
|
|
dissect_dnp3_al(al_tvb, pinfo, dnp3_tree);
|
|
}
|
|
|
|
static void
|
|
al_defragment_init(void)
|
|
{
|
|
fragment_table_init(&al_fragment_table);
|
|
reassembled_table_init(&al_reassembled_table);
|
|
}
|
|
|
|
/* Register the protocol with Ethereal */
|
|
|
|
void
|
|
proto_register_dnp3(void)
|
|
{
|
|
|
|
/* Setup list of header fields */
|
|
static hf_register_info hf[] = {
|
|
{ &hf_dnp3_start,
|
|
{ "Start Bytes", "dnp3.start", FT_UINT16, BASE_HEX, NULL, 0x0, "Start Bytes", HFILL }},
|
|
|
|
{ &hf_dnp3_len,
|
|
{ "Length", "dnp3.len", FT_UINT8, BASE_DEC, NULL, 0x0, "Frame Data Length", HFILL }},
|
|
|
|
{ &hf_dnp3_ctl,
|
|
{ "Control", "dnp3.ctl", FT_UINT8, BASE_HEX, NULL, 0x0, "Frame Control Byte", HFILL }},
|
|
|
|
{ &hf_dnp3_ctl_prifunc,
|
|
{ "Control Function Code", "dnp3.ctl.prifunc", FT_UINT8, BASE_DEC,
|
|
VALS(dnp3_ctl_func_pri_vals), DNP3_CTL_FUNC, "Frame Control Function Code", HFILL }},
|
|
|
|
{ &hf_dnp3_ctl_secfunc,
|
|
{ "Control Function Code", "dnp3.ctl.secfunc", FT_UINT8, BASE_DEC,
|
|
VALS(dnp3_ctl_func_sec_vals), DNP3_CTL_FUNC, "Frame Control Function Code", HFILL }},
|
|
|
|
{ &hf_dnp3_ctl_dir,
|
|
{ "Direction", "dnp3.ctl.dir", FT_BOOLEAN, 8, TFS(&flags_set_truth), DNP3_CTL_DIR, "", HFILL }},
|
|
|
|
{ &hf_dnp3_ctl_prm,
|
|
{ "Primary", "dnp3.ctl.prm", FT_BOOLEAN, 8, TFS(&flags_set_truth), DNP3_CTL_PRM, "", HFILL }},
|
|
|
|
{ &hf_dnp3_ctl_fcb,
|
|
{ "Frame Count Bit", "dnp3.ctl.fcb", FT_BOOLEAN, 8, TFS(&flags_set_truth), DNP3_CTL_FCB, "", HFILL }},
|
|
|
|
{ &hf_dnp3_ctl_fcv,
|
|
{ "Frame Count Valid", "dnp3.ctl.fcv", FT_BOOLEAN, 8, TFS(&flags_set_truth), DNP3_CTL_FCV, "", HFILL }},
|
|
|
|
{ &hf_dnp3_ctl_dfc,
|
|
{ "Data Flow Control", "dnp3.ctl.dfc", FT_BOOLEAN, 8, TFS(&flags_set_truth), DNP3_CTL_DFC, "", HFILL }},
|
|
|
|
{ &hf_dnp3_dst,
|
|
{ "Destination", "dnp3.dst", FT_UINT16, BASE_DEC, NULL, 0x0, "Destination Address", HFILL }},
|
|
|
|
{ &hf_dnp3_src,
|
|
{ "Source", "dnp3.src", FT_UINT16, BASE_DEC, NULL, 0x0, "Source Address", HFILL }},
|
|
|
|
{ &hf_dnp_hdr_CRC,
|
|
{ "CRC", "dnp.hdr.CRC", FT_UINT16, BASE_HEX, NULL, 0x0, "", HFILL }},
|
|
|
|
{ &hf_dnp_hdr_CRC_bad,
|
|
{ "Bad CRC", "dnp.hdr.CRC_bad", FT_BOOLEAN, BASE_NONE, NULL, 0x0, "", HFILL }},
|
|
|
|
{ &hf_dnp3_tr_ctl,
|
|
{ "Transport Control", "dnp3.tr.ctl", FT_UINT8, BASE_HEX, NULL, 0x0, "Tranport Layer Control Byte", HFILL }},
|
|
|
|
{ &hf_dnp3_tr_fin,
|
|
{ "Final", "dnp3.tr.fin", FT_BOOLEAN, 8, TFS(&flags_set_truth), DNP3_TR_FIN, "", HFILL }},
|
|
|
|
{ &hf_dnp3_tr_fir,
|
|
{ "First", "dnp3.tr.fir", FT_BOOLEAN, 8, TFS(&flags_set_truth), DNP3_TR_FIR, "", HFILL }},
|
|
|
|
{ &hf_dnp3_tr_seq,
|
|
{ "Sequence", "dnp3.tr.seq", FT_UINT8, BASE_DEC, NULL, DNP3_TR_SEQ, "Frame Sequence Number", HFILL }},
|
|
|
|
{ &hf_dnp3_al_ctl,
|
|
{ "Application Control", "dnp3.al.ctl", FT_UINT8, BASE_HEX, NULL, 0x0, "Application Layer Control Byte", HFILL }},
|
|
|
|
{ &hf_dnp3_al_fir,
|
|
{ "First", "dnp3.al.fir", FT_BOOLEAN, 8, TFS(&flags_set_truth), DNP3_AL_FIR, "", HFILL }},
|
|
|
|
{ &hf_dnp3_al_fin,
|
|
{ "Final", "dnp3.al.fin", FT_BOOLEAN, 8, TFS(&flags_set_truth), DNP3_AL_FIN, "", HFILL }},
|
|
|
|
{ &hf_dnp3_al_con,
|
|
{ "Confirm", "dnp3.al.con", FT_BOOLEAN, 8, TFS(&flags_set_truth), DNP3_AL_CON, "", HFILL }},
|
|
|
|
{ &hf_dnp3_al_seq,
|
|
{ "Sequence", "dnp3.al.seq", FT_UINT8, BASE_DEC, NULL, DNP3_AL_SEQ, "Frame Sequence Number", HFILL }},
|
|
|
|
{ &hf_dnp3_al_func,
|
|
{ "Application Layer Function Code", "dnp3.al.func", FT_UINT8, BASE_DEC,
|
|
VALS(dnp3_al_func_vals), DNP3_AL_FUNC, "Application Function Code", HFILL }},
|
|
|
|
{ &hf_fragment,
|
|
{ "DNP 3.0 AL Fragment", "al.fragment", FT_FRAMENUM, BASE_NONE, NULL, 0x0, "DNP 3.0 Application Layer Fragment", HFILL }},
|
|
|
|
{ &hf_fragments,
|
|
{ "DNP 3.0 AL Fragments", "al.fragments", FT_NONE, BASE_NONE, NULL, 0x0, "DNP 3.0 Application Layer Fragments", HFILL }},
|
|
|
|
{ &hf_fragment_overlap,
|
|
{ "Fragment overlap", "al.fragment.overlap", FT_BOOLEAN, BASE_NONE, NULL, 0x0, "Fragment overlaps with other fragments", HFILL }},
|
|
|
|
{ &hf_fragment_overlap_conflict,
|
|
{ "Conflicting data in fragment overlap", "al.fragment.overlap.conflict", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
|
|
"Overlapping fragments contained conflicting data", HFILL }},
|
|
|
|
{ &hf_fragment_multiple_tails,
|
|
{ "Multiple tail fragments found", "al.fragment.multipletails", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
|
|
"Several tails were found when defragmenting the packet", HFILL }},
|
|
|
|
{ &hf_fragment_too_long_fragment,
|
|
{ "Fragment too long", "al.fragment.toolongfragment", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
|
|
"Fragment contained data past end of packet", HFILL }},
|
|
|
|
{ &hf_fragment_error,
|
|
{ "Defragmentation error", "al.fragment.error", FT_FRAMENUM, BASE_NONE, NULL, 0x0,
|
|
"Defragmentation error due to illegal fragments", HFILL }},
|
|
{ &hf_fragment_reassembled_in,
|
|
{ "Reassembled PDU In Frame", "al.fragment.reassembled_in", FT_FRAMENUM, BASE_NONE, NULL, 0x0,
|
|
"This PDU is reassembled in this frame", HFILL }}
|
|
};
|
|
|
|
/* Setup protocol subtree array */
|
|
static gint *ett[] = {
|
|
&ett_dnp3,
|
|
&ett_dnp3_dl,
|
|
&ett_dnp3_dl_ctl,
|
|
&ett_dnp3_tr_ctl,
|
|
&ett_dnp3_al_data,
|
|
&ett_dnp3_al,
|
|
&ett_dnp3_al_ctl,
|
|
&ett_fragment,
|
|
&ett_fragments
|
|
};
|
|
|
|
/* Register the protocol name and description */
|
|
proto_dnp3 = proto_register_protocol("Distributed Network Protocol 3.0",
|
|
"DNP 3.0", "dnp3");
|
|
|
|
/* Required function calls to register the header fields and subtrees used */
|
|
proto_register_field_array(proto_dnp3, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
|
|
al_defragment_init();
|
|
}
|
|
|
|
|
|
/* 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_dnp3(void)
|
|
{
|
|
dissector_handle_t dnp3_handle;
|
|
|
|
dnp3_handle = create_dissector_handle(dissect_dnp3, proto_dnp3);
|
|
dissector_add("tcp.port", TCP_PORT_DNP, dnp3_handle);
|
|
}
|