forked from osmocom/wireshark
![Bill Meier](/assets/img/avatar_default.png)
unused hf[] entries (which I should have done in the first place). svn path=/trunk/; revision=47390
442 lines
13 KiB
C
442 lines
13 KiB
C
/* packet-v5dl.c
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* Routines for V5 data link frame disassembly
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* Rolf Fiedler <rolf.fiedler@innoventif.de> using the LAPD code of
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* Gilbert Ramirez <gram@alumni.rice.edu>
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*
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* $Id$
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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
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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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/*
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* V5 Data Link Layer
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*
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* V5 references:
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* ETS 300 324-1
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* ETS 300 347-1
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*
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*/
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#include "config.h"
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#include <glib.h>
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#include <epan/packet.h>
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#include <epan/conversation.h>
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#include <epan/xdlc.h>
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#include <epan/crc16-tvb.h>
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static int proto_v5dl = -1;
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static int hf_v5dl_direction = -1;
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/* static int hf_v5dl_address = -1; */
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static int hf_v5dl_ef = -1;
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static int hf_v5dl_eah = -1;
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static int hf_v5dl_cr = -1;
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static int hf_v5dl_ea1 = -1;
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static int hf_v5dl_eal = -1;
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static int hf_v5dl_ea2 = -1;
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static int hf_v5dl_control = -1;
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static int hf_v5dl_n_r = -1;
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static int hf_v5dl_n_s = -1;
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static int hf_v5dl_p = -1;
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static int hf_v5dl_p_ext = -1;
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static int hf_v5dl_f = -1;
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static int hf_v5dl_f_ext = -1;
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static int hf_v5dl_s_ftype = -1;
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static int hf_v5dl_u_modifier_cmd = -1;
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static int hf_v5dl_u_modifier_resp = -1;
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static int hf_v5dl_ftype_i = -1;
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static int hf_v5dl_ftype_s_u = -1;
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static int hf_v5dl_ftype_s_u_ext = -1;
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static int hf_v5dl_checksum = -1;
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static int hf_v5dl_checksum_good = -1;
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static int hf_v5dl_checksum_bad = -1;
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static gint ett_v5dl = -1;
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static gint ett_v5dl_address = -1;
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static gint ett_v5dl_control = -1;
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static gint ett_v5dl_checksum = -1;
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static dissector_handle_t v52_handle;
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/*
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* Bits in the address field.
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*/
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#define V5DL_EAH 0xfc00 /* Service Access Point Identifier */
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#define V5DL_EAH_SHIFT 10
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#define V5DL_CR 0x0200 /* Command/Response bit */
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#define V5DL_EA1 0x0100 /* First Address Extension bit */
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#define V5DL_EAL 0x00fe /* Terminal Endpoint Identifier */
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#define V5DL_EAL_SHIFT 1
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#define V5DL_EA2 0x0001 /* Second Address Extension bit */
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static const value_string v5dl_direction_vals[] = {
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{ P2P_DIR_RECV, "Network->User"},
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{ P2P_DIR_SENT, "User->Network"},
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{ 0, NULL }
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};
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static const value_string v5dl_addr_vals[] = {
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{ 8175, "ISDN Protocol" },
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{ 8176, "PSTN Protocol" },
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{ 8177, "CONTROL Protocol" },
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{ 8178, "BCC Protocol" },
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{ 8179, "PROT Protocol" },
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{ 8180, "Link Control Protocol" },
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{ 8191, "VALUE RESERVED" },
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{ 0, NULL } };
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/* Used only for U frames */
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static const xdlc_cf_items v5dl_cf_items = {
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NULL,
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NULL,
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&hf_v5dl_p,
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&hf_v5dl_f,
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NULL,
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&hf_v5dl_u_modifier_cmd,
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&hf_v5dl_u_modifier_resp,
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NULL,
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&hf_v5dl_ftype_s_u
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};
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/* Used only for I and S frames */
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static const xdlc_cf_items v5dl_cf_items_ext = {
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&hf_v5dl_n_r,
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&hf_v5dl_n_s,
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&hf_v5dl_p_ext,
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&hf_v5dl_f_ext,
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&hf_v5dl_s_ftype,
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NULL,
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NULL,
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&hf_v5dl_ftype_i,
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&hf_v5dl_ftype_s_u_ext
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};
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#define MAX_V5DL_PACKET_LEN 1024
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static void
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dissect_v5dl(tvbuff_t*, packet_info*, proto_tree*);
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static void
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dissect_v5dl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_tree *v5dl_tree, *addr_tree;
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proto_item *v5dl_ti, *addr_ti;
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int direction;
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guint v5dl_header_len;
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guint16 control;
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#if 0
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proto_tree *checksum_tree;
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proto_item *checksum_ti;
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guint16 checksum, checksum_calculated;
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guint checksum_offset;
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#endif
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guint16 addr, cr, eah, eal, v5addr;
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gboolean is_response = 0;
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#if 0
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guint length, reported_length;
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#endif
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tvbuff_t *next_tvb;
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const char *srcname = "?";
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const char *dstname = "?";
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "V5DL");
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col_clear(pinfo->cinfo, COL_INFO);
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addr = tvb_get_ntohs(tvb, 0);
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cr = addr & V5DL_CR;
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eal = (addr & V5DL_EAL) >> V5DL_EAL_SHIFT;
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eah = (addr & V5DL_EAH) >> V5DL_EAH_SHIFT;
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v5addr = (eah << 7) + eal;
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v5dl_header_len = 2; /* addr */
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direction = pinfo->p2p_dir;
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if (pinfo->p2p_dir == P2P_DIR_RECV) {
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is_response = cr ? FALSE : TRUE;
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srcname = "Network";
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dstname = "User";
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}
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else if (pinfo->p2p_dir == P2P_DIR_SENT) {
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is_response = cr ? TRUE : FALSE;
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srcname = "User";
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dstname = "Network";
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}
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col_set_str(pinfo->cinfo, COL_RES_DL_SRC, srcname);
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col_set_str(pinfo->cinfo, COL_RES_DL_DST, dstname);
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if (tree) {
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proto_item *direction_ti;
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v5dl_ti = proto_tree_add_item(tree, proto_v5dl, tvb, 0, -1,
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ENC_NA);
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v5dl_tree = proto_item_add_subtree(v5dl_ti, ett_v5dl);
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/*
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* Don't show the direction if we don't know it.
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*/
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if (direction != P2P_DIR_UNKNOWN) {
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direction_ti = proto_tree_add_uint(v5dl_tree, hf_v5dl_direction,
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tvb, 0, 0, pinfo->p2p_dir);
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PROTO_ITEM_SET_GENERATED(direction_ti);
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}
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addr_ti = proto_tree_add_uint(v5dl_tree, hf_v5dl_ef, tvb,
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0, 2, v5addr);
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addr_tree = proto_item_add_subtree(addr_ti, ett_v5dl_address);
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proto_tree_add_uint(addr_tree, hf_v5dl_eah, tvb, 0, 1, addr);
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proto_tree_add_uint(addr_tree, hf_v5dl_cr, tvb, 0, 1, addr);
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proto_tree_add_uint(addr_tree, hf_v5dl_ea1, tvb, 0, 1, addr);
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proto_tree_add_uint(addr_tree, hf_v5dl_eal, tvb, 1, 1, addr);
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proto_tree_add_uint(addr_tree, hf_v5dl_ea2, tvb, 1, 1, addr);
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}
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else {
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v5dl_ti = NULL;
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v5dl_tree = NULL;
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}
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control = dissect_xdlc_control(tvb, 2, pinfo, v5dl_tree, hf_v5dl_control,
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ett_v5dl_control, &v5dl_cf_items, &v5dl_cf_items_ext, NULL, NULL,
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is_response, TRUE, FALSE);
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v5dl_header_len += XDLC_CONTROL_LEN(control, TRUE);
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if (tree)
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proto_item_set_len(v5dl_ti, v5dl_header_len);
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/*
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* XXX - the sample capture supplied with bug 7027 does not
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* appear to include checksums in the packets.
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*/
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#if 0
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/*
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* Check the checksum, if available.
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* The checksum is a CCITT CRC-16 at the end of the packet, so
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* if we don't have the entire packet in the capture - i.e., if
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* tvb_length(tvb) != tvb_reported_length(tvb) we can't check it.
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*/
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length = tvb_length(tvb);
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reported_length = tvb_reported_length(tvb);
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/*
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* If the reported length isn't big enough for the V5DL header
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* and 2 bytes of checksum, the packet is malformed, as the
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* checksum overlaps the header.
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*/
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if (reported_length < v5dl_header_len + 2)
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THROW(ReportedBoundsError);
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if (length == reported_length) {
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/*
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* There's no snapshot length cutting off any of the
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* packet.
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*/
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checksum_offset = reported_length - 2;
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checksum = tvb_get_ntohs(tvb, checksum_offset);
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checksum_calculated = crc16_ccitt_tvb(tvb, checksum_offset);
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checksum_calculated = g_htons(checksum_calculated); /* Note: g_htons() macro may eval arg multiple times */
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if (checksum == checksum_calculated) {
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checksum_ti = proto_tree_add_uint_format(v5dl_tree, hf_v5dl_checksum, tvb, checksum_offset,
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2, 0,
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"Checksum: 0x%04x [correct]",
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checksum);
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checksum_tree = proto_item_add_subtree(checksum_ti, ett_v5dl_checksum);
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proto_tree_add_boolean(checksum_tree, hf_v5dl_checksum_good, tvb, checksum_offset, 2, TRUE);
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proto_tree_add_boolean(checksum_tree, hf_v5dl_checksum_bad, tvb, checksum_offset, 2, FALSE);
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} else {
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checksum_ti = proto_tree_add_uint_format(v5dl_tree, hf_v5dl_checksum, tvb, checksum_offset,
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2, 0,
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"Checksum: 0x%04x [incorrect, should be 0x%04x]",
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checksum, checksum_calculated);
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checksum_tree = proto_item_add_subtree(checksum_ti, ett_v5dl_checksum);
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proto_tree_add_boolean(checksum_tree, hf_v5dl_checksum_good, tvb, checksum_offset, 2, FALSE);
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proto_tree_add_boolean(checksum_tree, hf_v5dl_checksum_bad, tvb, checksum_offset, 2, TRUE);
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}
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/*
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* Remove the V5DL header *and* the checksum.
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*/
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next_tvb = tvb_new_subset(tvb, v5dl_header_len,
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tvb_length_remaining(tvb, v5dl_header_len) - 2,
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tvb_reported_length_remaining(tvb, v5dl_header_len) - 2);
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} else {
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/*
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* Some or all of the packet is cut off by a snapshot
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* length.
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*/
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if (length == reported_length - 1) {
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/*
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* One byte is cut off, so there's only one
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* byte of checksum in the captured data.
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* Remove that byte from the captured length
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* and both bytes from the reported length.
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*/
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next_tvb = tvb_new_subset(tvb, v5dl_header_len,
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tvb_length_remaining(tvb, v5dl_header_len) - 1,
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tvb_reported_length_remaining(tvb, v5dl_header_len) - 2);
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} else {
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/*
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* Two or more bytes are cut off, so there are
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* no bytes of checksum in the captured data.
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* Just remove the checksum from the reported
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* length.
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*/
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next_tvb = tvb_new_subset(tvb, v5dl_header_len,
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tvb_length_remaining(tvb, v5dl_header_len),
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tvb_reported_length_remaining(tvb, v5dl_header_len) - 2);
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}
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}
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#else
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next_tvb = tvb_new_subset_remaining(tvb, v5dl_header_len);
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#endif
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if (XDLC_IS_INFORMATION(control)) {
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/* call V5.2 dissector */
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call_dissector(v52_handle, next_tvb, pinfo, tree);
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}
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}
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void
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proto_reg_handoff_v5dl(void);
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void
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proto_register_v5dl(void)
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{
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static hf_register_info hf[] = {
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{ &hf_v5dl_direction,
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{ "Direction", "v5dl.direction", FT_UINT8, BASE_DEC, VALS(v5dl_direction_vals), 0x0,
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NULL, HFILL }},
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#if 0
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{ &hf_v5dl_address,
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{ "Address Field", "v5dl.address", FT_UINT16, BASE_HEX, NULL, 0x0,
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"Address", HFILL }},
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#endif
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{ &hf_v5dl_ef,
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{ "EF", "v5dl.ef", FT_UINT16, BASE_DEC, VALS(v5dl_addr_vals), 0x0,
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"Envelope Function Address", HFILL }},
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{ &hf_v5dl_eah,
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{ "EAH", "v5dl.eah", FT_UINT16, BASE_DEC, NULL, V5DL_EAH,
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"Envelope Address High", HFILL }},
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{ &hf_v5dl_cr,
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{ "C/R", "v5dl.cr", FT_UINT16, BASE_DEC, NULL, V5DL_CR,
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"Command/Response bit", HFILL }},
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{ &hf_v5dl_ea1,
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{ "EA1", "v5dl.ea1", FT_UINT16, BASE_DEC, NULL, V5DL_EA1,
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"First Address Extension bit", HFILL }},
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{ &hf_v5dl_eal,
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{ "EAL", "v5dl.eal", FT_UINT16, BASE_DEC, NULL, V5DL_EAL,
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"Envelope Address Low", HFILL }},
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{ &hf_v5dl_ea2,
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{ "EA2", "v5dl.ea2", FT_UINT16, BASE_DEC, NULL, V5DL_EA2,
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"Second Address Extension bit", HFILL }},
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{ &hf_v5dl_control,
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{ "Control Field", "v5dl.control", FT_UINT16, BASE_HEX, NULL, 0x0,
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NULL, HFILL }},
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{ &hf_v5dl_n_r,
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{ "N(R)", "v5dl.control.n_r", FT_UINT16, BASE_DEC,
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NULL, XDLC_N_R_EXT_MASK, NULL, HFILL }},
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{ &hf_v5dl_n_s,
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{ "N(S)", "v5dl.control.n_s", FT_UINT16, BASE_DEC,
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NULL, XDLC_N_S_EXT_MASK, NULL, HFILL }},
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{ &hf_v5dl_p,
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{ "Poll", "v5dl.control.p", FT_BOOLEAN, 8,
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TFS(&tfs_set_notset), XDLC_P_F, NULL, HFILL }},
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{ &hf_v5dl_p_ext,
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{ "Poll", "v5dl.control.p", FT_BOOLEAN, 16,
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TFS(&tfs_set_notset), XDLC_P_F_EXT, NULL, HFILL }},
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{ &hf_v5dl_f,
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{ "Final", "v5dl.control.f", FT_BOOLEAN, 8,
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TFS(&tfs_set_notset), XDLC_P_F, NULL, HFILL }},
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{ &hf_v5dl_f_ext,
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{ "Final", "v5dl.control.f", FT_BOOLEAN, 16,
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TFS(&tfs_set_notset), XDLC_P_F_EXT, NULL, HFILL }},
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{ &hf_v5dl_s_ftype,
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{ "Supervisory frame type", "v5dl.control.s_ftype", FT_UINT16, BASE_HEX,
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VALS(stype_vals), XDLC_S_FTYPE_MASK, NULL, HFILL }},
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{ &hf_v5dl_u_modifier_cmd,
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{ "Command", "v5dl.control.u_modifier_cmd", FT_UINT8, BASE_HEX,
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VALS(modifier_vals_cmd), XDLC_U_MODIFIER_MASK, NULL, HFILL }},
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{ &hf_v5dl_u_modifier_resp,
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{ "Response", "v5dl.control.u_modifier_resp", FT_UINT8, BASE_HEX,
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VALS(modifier_vals_resp), XDLC_U_MODIFIER_MASK, NULL, HFILL }},
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{ &hf_v5dl_ftype_i,
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{ "Frame type", "v5dl.control.ftype", FT_UINT16, BASE_HEX,
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VALS(ftype_vals), XDLC_I_MASK, NULL, HFILL }},
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{ &hf_v5dl_ftype_s_u,
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{ "Frame type", "v5dl.control.ftype", FT_UINT8, BASE_HEX,
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VALS(ftype_vals), XDLC_S_U_MASK, NULL, HFILL }},
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{ &hf_v5dl_ftype_s_u_ext,
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{ "Frame type", "v5dl.control.ftype", FT_UINT16, BASE_HEX,
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VALS(ftype_vals), XDLC_S_U_MASK, NULL, HFILL }},
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{ &hf_v5dl_checksum,
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{ "Checksum", "v5dl.checksum", FT_UINT16, BASE_HEX,
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NULL, 0x0, "Details at: http://www.wireshark.org/docs/wsug_html_chunked/ChAdvChecksums.html", HFILL }},
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{ &hf_v5dl_checksum_good,
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{ "Good Checksum", "v5dl.checksum_good", FT_BOOLEAN, BASE_NONE,
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NULL, 0x0, "True: checksum matches packet content; False: doesn't match content or not checked", HFILL }},
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{ &hf_v5dl_checksum_bad,
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{ "Bad Checksum", "v5dl.checksum_bad", FT_BOOLEAN, BASE_NONE,
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NULL, 0x0, "True: checksum doesn't match packet content; False: matches content or not checked", HFILL }}
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};
|
|
|
|
static gint *ett[] = {
|
|
&ett_v5dl,
|
|
&ett_v5dl_address,
|
|
&ett_v5dl_control,
|
|
&ett_v5dl_checksum
|
|
};
|
|
|
|
proto_v5dl = proto_register_protocol("V5 Data Link Layer",
|
|
"V5DL", "v5dl");
|
|
proto_register_field_array (proto_v5dl, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
|
|
register_dissector("v5dl", dissect_v5dl, proto_v5dl);
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_v5dl(void)
|
|
{
|
|
v52_handle = find_dissector("v52");
|
|
}
|