forked from osmocom/wireshark
100 lines
3.0 KiB
C
100 lines
3.0 KiB
C
/* packet-wap.c
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*
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* Utility routines for WAP dissectors
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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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* WAP dissector based on original work by Ben Fowler
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* Updated by Neil Hunter <neil.hunter@energis-squared.com>
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* WTLS support by Alexandre P. Ferreira (Splice IP)
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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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#include "config.h"
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#include <epan/packet.h>
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#include "packet-wap.h"
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/*
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* Accessor to retrieve variable length int as used in WAP protocol.
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* The value is encoded in the lower 7 bits. If the top bit is set, then the
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* value continues into the next byte.
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* The octetCount parameter holds the number of bytes read in order to return
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* the final value. Can be pre-initialised to start at offset+count.
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*/
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guint
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tvb_get_guintvar (tvbuff_t *tvb, guint offset, guint *octetCount, packet_info *pinfo, expert_field *ei)
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{
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guint value = 0;
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guint octet;
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guint counter = 0;
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char cont = 1;
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#ifdef DEBUG
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if (octetCount != NULL)
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{
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fprintf (stderr, "dissect_wap: Starting tvb_get_guintvar at offset %d, count=%d\n", offset, *octetCount);
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/* counter = *octetCount; */
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}
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else
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{
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fprintf (stderr, "dissect_wap: Starting tvb_get_guintvar at offset %d, count=NULL\n", offset);
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}
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#endif
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while (cont != 0)
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{
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value <<= 7; /* Value only exists in 7 of the 8 bits */
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octet = tvb_get_guint8 (tvb, offset+counter);
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counter += 1;
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value += (octet & 0x7F);
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cont = (octet & 0x80);
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#ifdef DEBUG
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fprintf (stderr, "dissect_wap: computing: octet is %d (0x%02x), count=%d, value=%d, cont=%d\n",
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octet, octet, counter, value, cont);
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#endif
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}
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if (counter > 5) {
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proto_tree_add_expert(NULL, pinfo, ei, tvb, offset, counter);
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value = 0;
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}
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if (octetCount != NULL)
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{
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*octetCount = counter;
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#ifdef DEBUG
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fprintf (stderr, "dissect_wap: Leaving tvb_get_guintvar count=%d, value=%u\n", *octetCount, value);
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#endif
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}
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return (value);
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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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