diff options
| author | MustBeArt <paul@mustbeart.com> | 2017-01-01 08:47:40 -0800 |
|---|---|---|
| committer | Martin Kaiser <wireshark@kaiser.cx> | 2017-01-07 12:05:16 +0000 |
| commit | fb9ac503c16e88408a53e808f17f19f63787f2de (patch) | |
| tree | 749f5459e2a039f2e8dd5e26ca85ed1fc6ba72b7 /epan/dissectors/packet-dvb-s2-bb.c | |
| parent | 0dcbfab4265b4f494a7b162d2c34c99ed7994541 (diff) | |
DVB-S2 BB: Fix BB header CRC checks
Fix problem with baseband header CRC check that caused almost all
baseband frames to show a spurious CRC error, introduced with
proto_tree_add_checksum.
Change-Id: I6b2f9680507eeb79e59b825f3ac9e4cee1033976
Reviewed-on: https://code.wireshark.org/review/19567
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Martin Kaiser <wireshark@kaiser.cx>
Diffstat (limited to 'epan/dissectors/packet-dvb-s2-bb.c')
| -rw-r--r-- | epan/dissectors/packet-dvb-s2-bb.c | 13 |
1 files changed, 4 insertions, 9 deletions
diff --git a/epan/dissectors/packet-dvb-s2-bb.c b/epan/dissectors/packet-dvb-s2-bb.c index fda51b1f56..04d1abb28b 100644 --- a/epan/dissectors/packet-dvb-s2-bb.c +++ b/epan/dissectors/packet-dvb-s2-bb.c @@ -546,7 +546,7 @@ static const range_string gse_proto_str[] = { #define DVB_S2_GSE_CRC32_LEN 4 /* *** helper functions *** */ -static gboolean check_crc8(tvbuff_t *p, guint8 len, guint8 offset, guint8 received_fcs) +static guint8 compute_crc8(tvbuff_t *p, guint8 len, guint8 offset) { int i; guint8 crc = 0, tmp; @@ -555,10 +555,7 @@ static gboolean check_crc8(tvbuff_t *p, guint8 len, guint8 offset, guint8 receiv tmp = tvb_get_guint8(p, offset++); crc = crc8_table[crc ^ tmp]; } - if (received_fcs == crc) - return TRUE; - else - return FALSE; + return crc; } /* *** Code to actually dissect the packets *** */ @@ -709,7 +706,7 @@ static gboolean test_dvb_s2_crc(tvbuff_t *tvb, guint offset) { input8 = tvb_get_guint8(tvb, offset + DVB_S2_BB_OFFS_CRC); - if (!check_crc8(tvb, DVB_S2_BB_HEADER_LEN - 1, offset, input8)) + if (compute_crc8(tvb, DVB_S2_BB_HEADER_LEN - 1, offset) != input8) return FALSE; else return TRUE; @@ -787,11 +784,9 @@ static int dissect_dvb_s2_bb(tvbuff_t *tvb, int cur_off, proto_tree *tree, packe new_off += 2; proto_tree_add_item(dvb_s2_bb_tree, hf_dvb_s2_bb_syncd, tvb, cur_off + DVB_S2_BB_OFFS_SYNCD, 2, ENC_BIG_ENDIAN); - input8 = tvb_get_guint8(tvb, cur_off + DVB_S2_BB_OFFS_CRC); new_off += 1; - proto_tree_add_checksum(dvb_s2_bb_tree, tvb, cur_off + DVB_S2_BB_OFFS_CRC, hf_dvb_s2_bb_crc, hf_dvb_s2_bb_crc_status, &ei_dvb_s2_bb_crc, pinfo, - check_crc8(tvb, DVB_S2_BB_HEADER_LEN - 1, cur_off, input8), ENC_NA, PROTO_CHECKSUM_VERIFY); + compute_crc8(tvb, DVB_S2_BB_HEADER_LEN - 1, cur_off), ENC_NA, PROTO_CHECKSUM_VERIFY); while (bb_data_len) { /* start DVB-GSE dissector */ |