diff options
| author | Martin Kaiser <wireshark@kaiser.cx> | 2013-03-14 07:01:37 +0000 |
|---|---|---|
| committer | Martin Kaiser <wireshark@kaiser.cx> | 2013-03-14 07:01:37 +0000 |
| commit | 3fa84d8af5a6850851a932e44baec89b15c4be0a (patch) | |
| tree | 22287327db7e53cd2b8af15dcf43ac9f2a59511f | |
| parent | 14613716eaa66879e37864fdee9fa3fd11fa9c99 (diff) | |
From Weston Schmidt
fix DSM-CC CRC calculation
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=8466
svn path=/trunk/; revision=48292
| -rw-r--r-- | epan/dissectors/packet-mpeg-dsmcc.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/epan/dissectors/packet-mpeg-dsmcc.c b/epan/dissectors/packet-mpeg-dsmcc.c index 348d6a223a..4a86c7746e 100644 --- a/epan/dissectors/packet-mpeg-dsmcc.c +++ b/epan/dissectors/packet-mpeg-dsmcc.c @@ -595,9 +595,9 @@ dissect_dsmcc_ts(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree_in, void *d { proto_item *pi; proto_tree *tree; + guint crc_len; guint8 tid; guint16 sect_len; - guint crc_start; guint32 crc, calculated_crc; const char *label; tvbuff_t *sub_tvb; @@ -624,7 +624,6 @@ dissect_dsmcc_ts(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree_in, void *d sect_len = tvb_get_ntohs(tvb, offset); sect_len &= DSMCC_LENGTH_MASK; offset += 2; - crc_start = offset; proto_tree_add_item(tree, hf_dsmcc_table_id_extension, tvb, offset, 2, ENC_BIG_ENDIAN); @@ -662,24 +661,25 @@ dissect_dsmcc_ts(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree_in, void *d break; } + crc_len = 3 + sect_len - 4; /* Add the header, remove the crc */ if (ssi) { - crc = tvb_get_ntohl(tvb, crc_start+sect_len-4); + crc = tvb_get_ntohl(tvb, crc_len); calculated_crc = crc; label = "Unverified"; if (dsmcc_sect_check_crc) { label = "Verified"; - calculated_crc = crc32_mpeg2_tvb_offset(tvb, crc_start, sect_len-4); + calculated_crc = crc32_mpeg2_tvb_offset(tvb, 0, crc_len); } if (calculated_crc == crc) { proto_tree_add_uint_format( tree, hf_dsmcc_crc, tvb, - crc_start+sect_len-4, 4, crc, "CRC: 0x%08x [%s]", crc, label); + crc_len, 4, crc, "CRC: 0x%08x [%s]", crc, label); } else { proto_item *msg_error = NULL; msg_error = proto_tree_add_uint_format( tree, hf_dsmcc_crc, tvb, - crc_start+sect_len-4, 4, crc, + crc_len, 4, crc, "CRC: 0x%08x [Failed Verification (Calculated: 0x%08x)]", crc, calculated_crc ); PROTO_ITEM_SET_GENERATED(msg_error); @@ -689,7 +689,7 @@ dissect_dsmcc_ts(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree_in, void *d } else { /* TODO: actually check the checksum */ proto_tree_add_item(tree, hf_dsmcc_checksum, tvb, - crc_start+sect_len-4, 4, ENC_BIG_ENDIAN); + crc_len, 4, ENC_BIG_ENDIAN); } return TRUE; |