forked from osmocom/wireshark
155 lines
3.4 KiB
C
155 lines
3.4 KiB
C
/* crc32-tvb.c
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* CRC-32 tvbuff routines
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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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* SPDX-License-Identifier: GPL-2.0-or-later
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*
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* Credits:
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*
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* Table from Solomon Peachy
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* Routine from Chris Waters
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*/
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#include "config.h"
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#include <glib.h>
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#include <epan/tvbuff.h>
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#include <wsutil/crc32.h>
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#include <epan/crc32-tvb.h>
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guint32
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crc32_ccitt_tvb(tvbuff_t *tvb, guint len)
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{
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const guint8* buf;
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tvb_ensure_bytes_exist(tvb, 0, len); /* len == -1 not allowed */
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buf = tvb_get_ptr(tvb, 0, len);
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return ( crc32_ccitt_seed(buf, len, CRC32_CCITT_SEED) );
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}
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guint32
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crc32_ccitt_tvb_offset(tvbuff_t *tvb, guint offset, guint len)
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{
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const guint8* buf;
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tvb_ensure_bytes_exist(tvb, offset, len); /* len == -1 not allowed */
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buf = tvb_get_ptr(tvb, offset, len);
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return ( crc32_ccitt(buf, len) );
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}
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guint32
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crc32_ccitt_tvb_seed(tvbuff_t *tvb, guint len, guint32 seed)
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{
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const guint8* buf;
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tvb_ensure_bytes_exist(tvb, 0, len); /* len == -1 not allowed */
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buf = tvb_get_ptr(tvb, 0, len);
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return ( crc32_ccitt_seed(buf, len, seed) );
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}
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guint32
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crc32_ccitt_tvb_offset_seed(tvbuff_t *tvb, guint offset, guint len,
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guint32 seed)
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{
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const guint8* buf;
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tvb_ensure_bytes_exist(tvb, offset, len); /* len == -1 not allowed */
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buf = tvb_get_ptr(tvb, offset, len);
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return ( crc32_ccitt_seed(buf, len, seed) );
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}
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guint32
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crc32c_tvb_offset_calculate(tvbuff_t *tvb, guint offset, guint len, guint32 seed)
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{
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const guint8* buf;
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tvb_ensure_bytes_exist(tvb, offset, len); /* len == -1 not allowed */
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buf = tvb_get_ptr(tvb, offset, len);
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return ( crc32c_calculate(buf, len, seed) );
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}
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/*
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* IEEE 802.x version (Ethernet and 802.11, at least) - byte-swap
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* the result of "crc32()".
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*
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* XXX - does this mean we should fetch the Ethernet and 802.11
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* FCS with "tvb_get_letohl()" rather than "tvb_get_ntohl()",
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* or is fetching it big-endian and byte-swapping the CRC done
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* to cope with 802.x sending stuff out in reverse bit order?
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*/
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guint32
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crc32_802_tvb(tvbuff_t *tvb, guint len)
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{
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guint32 c_crc;
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c_crc = crc32_ccitt_tvb(tvb, len);
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/* Byte reverse. */
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c_crc = GUINT32_SWAP_LE_BE(c_crc);
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return ( c_crc );
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}
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guint32
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crc32_mpeg2_tvb_offset_seed(tvbuff_t *tvb, guint offset,
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guint len, guint32 seed)
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{
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const guint8* buf;
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tvb_ensure_bytes_exist(tvb, offset, len); /* len == -1 not allowed */
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buf = tvb_get_ptr(tvb, offset, len);
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return ( crc32_mpeg2_seed(buf, len, seed) );
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}
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guint32
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crc32_mpeg2_tvb(tvbuff_t *tvb, guint len)
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{
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return ( crc32_mpeg2_tvb_offset_seed(tvb, 0, len, CRC32_MPEG2_SEED) );
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}
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guint32
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crc32_mpeg2_tvb_offset(tvbuff_t *tvb, guint offset, guint len)
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{
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return ( crc32_mpeg2_tvb_offset_seed(tvb, offset, len, CRC32_MPEG2_SEED) );
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}
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guint32
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crc32_mpeg2_tvb_seed(tvbuff_t *tvb, guint len, guint32 seed)
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{
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return ( crc32_mpeg2_tvb_offset_seed(tvb, 0, len, seed) );
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}
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guint32 crc32_0x0AA725CF_tvb_offset_seed(tvbuff_t *tvb,
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guint offset, guint len, guint32 seed)
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{
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const guint8 *buf;
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tvb_ensure_bytes_exist(tvb, offset, len); /* len == -1 not allowed */
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buf = tvb_get_ptr(tvb, offset, len);
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return crc32_0x0AA725CF_seed(buf, len, seed);
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}
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/*
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* Editor modelines - https://www.wireshark.org/tools/modelines.html
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*
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* Local variables:
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* c-basic-offset: 8
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* tab-width: 8
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* indent-tabs-mode: t
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* End:
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*
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* vi: set shiftwidth=8 tabstop=8 noexpandtab:
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* :indentSize=8:tabSize=8:noTabs=false:
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*/
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