diff options
Diffstat (limited to 'epan/dissectors/packet-mstp.c')
| -rw-r--r-- | epan/dissectors/packet-mstp.c | 97 |
1 files changed, 16 insertions, 81 deletions
diff --git a/epan/dissectors/packet-mstp.c b/epan/dissectors/packet-mstp.c index a97365f655..5b3c3a842f 100644 --- a/epan/dissectors/packet-mstp.c +++ b/epan/dissectors/packet-mstp.c @@ -86,8 +86,7 @@ static int hf_mstp_frame_vendor_id = -1; static int hf_mstp_frame_pdu_len = -1; static int hf_mstp_frame_crc8 = -1; static int hf_mstp_frame_crc16 = -1; -static int hf_mstp_frame_checksum_bad = -1; -static int hf_mstp_frame_checksum_good = -1; +static int hf_mstp_frame_checksum_status = -1; static expert_field ei_mstp_frame_pdu_len = EI_INIT; static expert_field ei_mstp_frame_checksum_bad = EI_INIT; @@ -190,12 +189,11 @@ dissect_mstp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item; #if defined(BACNET_MSTP_CHECKSUM_VALIDATE) /* used to calculate the crc value */ - guint8 crc8 = 0xFF, framecrc8; - guint16 crc16 = 0xFFFF, framecrc16; + guint8 crc8 = 0xFF; + guint16 crc16 = 0xFFFF; guint8 crcdata; guint16 i; /* loop counter */ guint16 max_len = 0; - proto_tree *checksum_tree; #endif col_set_str(pinfo->cinfo, COL_PROTOCOL, "BACnet"); @@ -228,39 +226,11 @@ dissect_mstp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, crc8 = CRC_Calc_Header(crcdata, crc8); } crc8 = ~crc8; - framecrc8 = tvb_get_guint8(tvb, offset+5); - if (framecrc8 == crc8) { - item = proto_tree_add_uint_format_value(subtree, hf_mstp_frame_crc8, - tvb, offset+5, 1, framecrc8, - "0x%02x [correct]", framecrc8); - checksum_tree = proto_item_add_subtree(item, ett_bacnet_mstp_checksum); - item = proto_tree_add_boolean(checksum_tree, - hf_mstp_frame_checksum_good, - tvb, offset+5, 1, TRUE); - PROTO_ITEM_SET_GENERATED(item); - item = proto_tree_add_boolean(checksum_tree, - hf_mstp_frame_checksum_bad, - tvb, offset+5, 1, FALSE); - PROTO_ITEM_SET_GENERATED(item); - } else { - item = proto_tree_add_uint_format_value(subtree, hf_mstp_frame_crc8, - tvb, offset+5, 1, framecrc8, - "0x%02x [incorrect, should be 0x%02x]", - framecrc8, crc8); - checksum_tree = proto_item_add_subtree(item, ett_bacnet_mstp_checksum); - item = proto_tree_add_boolean(checksum_tree, - hf_mstp_frame_checksum_good, - tvb, offset+5, 1, FALSE); - PROTO_ITEM_SET_GENERATED(item); - item = proto_tree_add_boolean(checksum_tree, - hf_mstp_frame_checksum_bad, - tvb, offset+5, 1, TRUE); - PROTO_ITEM_SET_GENERATED(item); - expert_add_info(pinfo, item, &ei_mstp_frame_checksum_bad); - } + proto_tree_add_checksum(subtree, tvb, offset+5, hf_mstp_frame_crc8, hf_mstp_frame_checksum_status, &ei_mstp_frame_checksum_bad, pinfo, crc8, + ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY); #else - proto_tree_add_item(subtree, hf_mstp_frame_crc8, - tvb, offset+5, 1, ENC_LITTLE_ENDIAN); + proto_tree_add_checksum(subtree, tvb, offset+5, hf_mstp_frame_crc8, hf_mstp_frame_checksum_status, &ei_mstp_frame_checksum_bad, pinfo, 0, + PROTO_CHECKSUM_NO_FLAGS); #endif /* dissect BACnet PDU if there is one */ @@ -300,42 +270,12 @@ dissect_mstp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, crc16 = ~crc16; /* convert it to on-the-wire format */ crc16 = g_htons(crc16); - /* get the actual CRC from the frame */ - framecrc16 = tvb_get_ntohs(tvb, offset+mstp_frame_pdu_len); - if (framecrc16 == crc16) { - item = proto_tree_add_uint_format_value(subtree, hf_mstp_frame_crc16, - tvb, offset+mstp_frame_pdu_len, 2, framecrc16, - "0x%04x [correct]", framecrc16); - checksum_tree = proto_item_add_subtree(item, - ett_bacnet_mstp_checksum); - item = proto_tree_add_boolean(checksum_tree, - hf_mstp_frame_checksum_good, - tvb, offset+mstp_frame_pdu_len, 2, TRUE); - PROTO_ITEM_SET_GENERATED(item); - item = proto_tree_add_boolean(checksum_tree, - hf_mstp_frame_checksum_bad, - tvb, offset+mstp_frame_pdu_len, 2, FALSE); - PROTO_ITEM_SET_GENERATED(item); - } else { - item = proto_tree_add_uint_format_value(subtree, hf_mstp_frame_crc16, - tvb, offset+mstp_frame_pdu_len, 2, framecrc16, - "0x%04x [incorrect, should be 0x%04x]", - framecrc16, crc16); - checksum_tree = proto_item_add_subtree(item, - ett_bacnet_mstp_checksum); - item = proto_tree_add_boolean(checksum_tree, - hf_mstp_frame_checksum_good, - tvb, offset+mstp_frame_pdu_len, 2, FALSE); - PROTO_ITEM_SET_GENERATED(item); - item = proto_tree_add_boolean(checksum_tree, - hf_mstp_frame_checksum_bad, - tvb, offset+mstp_frame_pdu_len, 2, TRUE); - PROTO_ITEM_SET_GENERATED(item); - expert_add_info(pinfo, item, &ei_mstp_frame_checksum_bad); - } + + proto_tree_add_checksum(subtree, tvb, offset+mstp_frame_pdu_len, hf_mstp_frame_crc16, hf_mstp_frame_checksum_status, &ei_mstp_frame_checksum_bad, pinfo, crc16, + ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY); #else - proto_tree_add_item(subtree, hf_mstp_frame_crc16, - tvb, offset+mstp_frame_pdu_len, 2, ENC_LITTLE_ENDIAN); + proto_tree_add_checksum(subtree, tvb, offset+mstp_frame_pdu_len, hf_mstp_frame_crc16, hf_mstp_frame_checksum_status, &ei_mstp_frame_checksum_bad, pinfo, 0, + ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS); #endif } } @@ -427,16 +367,11 @@ proto_register_mstp(void) FT_UINT16, BASE_HEX, NULL, 0, "MS/TP Data CRC", HFILL } }, - { &hf_mstp_frame_checksum_bad, - { "Bad", "mstp.checksum_bad", - FT_BOOLEAN, BASE_NONE, NULL, 0x0, - "True: checksum doesn't match packet content; False: matches content or not checked", HFILL } + { &hf_mstp_frame_checksum_status, + { "Checksum status", "mstp.checksum.status", + FT_UINT8, BASE_NONE, VALS(proto_checksum_vals), 0x0, + NULL, HFILL } }, - { &hf_mstp_frame_checksum_good, - { "Good", "mstp.checksum_good", - FT_BOOLEAN, BASE_NONE, NULL, 0x0, - "True: checksum matches packet content; False: doesn't match content or not checked", HFILL } - } }; static gint *ett[] = { |