forked from osmocom/wireshark
Add code to check the AAL5 CRC, and report it as a CRC rather than as a
checksum. svn path=/trunk/; revision=6882
This commit is contained in:
Guy Harris
parent
a0c5cac89d
commit
241ac4f61c
141
packet-atm.c
141
packet-atm.c
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@ -1,7 +1,7 @@
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/* packet-atm.c
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* Routines for ATM packet disassembly
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*
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* $Id: packet-atm.c,v 1.53 2003/01/09 01:55:11 guy Exp $
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* $Id: packet-atm.c,v 1.54 2003/01/09 02:55:21 guy Exp $
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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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@ -788,6 +788,130 @@ capture_atm(const union wtap_pseudo_header *pseudo_header, const guchar *pd,
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ld->other++;
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}
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/*
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* Charles Michael Heard's CRC-32 code, from
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*
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* http://cell-relay.indiana.edu/cell-relay/publications/software/CRC/32bitCRC.c.html
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*
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* with the CRC table initialized with values computed by
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* his "gen_crc_table()" routine, rather than by calling that routine
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* at run time, and with various data type cleanups.
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*/
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/* crc32h.c -- package to compute 32-bit CRC one byte at a time using */
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/* the high-bit first (Big-Endian) bit ordering convention */
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/* */
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/* Synopsis: */
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/* gen_crc_table() -- generates a 256-word table containing all CRC */
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/* remainders for every possible 8-bit byte. It */
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/* must be executed (once) before any CRC updates. */
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/* */
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/* unsigned update_crc(crc_accum, data_blk_ptr, data_blk_size) */
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/* unsigned crc_accum; char *data_blk_ptr; int data_blk_size; */
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/* Returns the updated value of the CRC accumulator after */
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/* processing each byte in the addressed block of data. */
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/* */
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/* It is assumed that an unsigned long is at least 32 bits wide and */
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/* that the predefined type char occupies one 8-bit byte of storage. */
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/* */
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/* The generator polynomial used for this version of the package is */
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/* x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x^1+x^0 */
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/* as specified in the Autodin/Ethernet/ADCCP protocol standards. */
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/* Other degree 32 polynomials may be substituted by re-defining the */
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/* symbol POLYNOMIAL below. Lower degree polynomials must first be */
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/* multiplied by an appropriate power of x. The representation used */
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/* is that the coefficient of x^0 is stored in the LSB of the 32-bit */
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/* word and the coefficient of x^31 is stored in the most significant */
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/* bit. The CRC is to be appended to the data most significant byte */
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/* first. For those protocols in which bytes are transmitted MSB */
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/* first and in the same order as they are encountered in the block */
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/* this convention results in the CRC remainder being transmitted with */
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/* the coefficient of x^31 first and with that of x^0 last (just as */
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/* would be done by a hardware shift register mechanization). */
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/* */
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/* The table lookup technique was adapted from the algorithm described */
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/* by Avram Perez, Byte-wise CRC Calculations, IEEE Micro 3, 40 (1983).*/
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static const guint32 crc_table[256] = {
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0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9,
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0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005,
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0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
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0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
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0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9,
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0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
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0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011,
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0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd,
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0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
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0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
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0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81,
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0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
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0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49,
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0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
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0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
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0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d,
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0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae,
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0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
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0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
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0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca,
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0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
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0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02,
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0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066,
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0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
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0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e,
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0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692,
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0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
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0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a,
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0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
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0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
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0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686,
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0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a,
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0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
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0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
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0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f,
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0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
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0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47,
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0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b,
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0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
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0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
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0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7,
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0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
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0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f,
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0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
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0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
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0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b,
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0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f,
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0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
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0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
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0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
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0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
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0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24,
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0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30,
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0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
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0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088,
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0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654,
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0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
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0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c,
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0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
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0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
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0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0,
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0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c,
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0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
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0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4,
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};
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static guint32
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update_crc(guint32 crc_accum, const guint8 *data_blk_ptr, int data_blk_size)
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{
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register int i, j;
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/* update the CRC on the data block one byte at a time */
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for (j = 0; j < data_blk_size; j++) {
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i = ( (int) ( crc_accum >> 24) ^ *data_blk_ptr++ ) & 0xff;
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crc_accum = ( crc_accum << 8 ) ^ crc_table[i];
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}
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return crc_accum;
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}
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static void
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dissect_reassembled_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
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proto_tree *atm_tree, gboolean truncated)
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@ -796,6 +920,8 @@ dissect_reassembled_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
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guint16 aal5_length;
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int pad_length;
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tvbuff_t *next_tvb;
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guint32 crc;
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guint32 calc_crc;
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/*
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* This is reassembled traffic, so the cell headers are missing;
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@ -857,7 +983,7 @@ dissect_reassembled_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
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pinfo->pseudo_header->atm.aal5t_u2u & 0xFF);
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proto_tree_add_text(atm_tree, tvb, 0, 0, "AAL5 len: %u",
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pinfo->pseudo_header->atm.aal5t_len);
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proto_tree_add_text(atm_tree, tvb, 0, 0, "AAL5 checksum: 0x%08X",
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proto_tree_add_text(atm_tree, tvb, 0, 0, "AAL5 CRC: 0x%08X",
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pinfo->pseudo_header->atm.aal5t_chksum);
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}
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}
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@ -897,11 +1023,12 @@ dissect_reassembled_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
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tvb_get_guint8(tvb, length - 7));
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proto_tree_add_text(atm_tree, tvb, length - 6, 2, "AAL5 len: %u",
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aal5_length);
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/*
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* XXX - check the checksum.
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*/
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proto_tree_add_text(atm_tree, tvb, length - 4, 4, "AAL5 checksum: 0x%08X",
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tvb_get_ntohl(tvb, length - 4));
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crc = tvb_get_ntohl(tvb, length - 4);
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calc_crc = update_crc(0xFFFFFFFF, tvb_get_ptr(tvb, 0, length),
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length);
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proto_tree_add_text(atm_tree, tvb, length - 4, 4,
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"AAL5 CRC (%s): 0x%08X",
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(calc_crc == 0xC704DD7B) ? "correct" : "incorrect", crc);
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}
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next_tvb = tvb_new_subset(tvb, 0, aal5_length, aal5_length);
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}
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