Hi folks,
We think we've found a bug in STANAG 5066 SIS layer dissector.
Problem is at S_EXPEDITED_UNIDATA_INDICATION S_Prim's parser
and occurs when we receive a U_PDU via expedited unidata channel.
Dissector tries to parse first 2 bytes of U_PDU as a header size of type
21 s_prim (S_UNIDATA_INDICATION). But, this is not an wanted process on
that parser. Maybe, it was forgotten unchanged from
S_UNIDATA_INDICATION dissector while copying it. So it shows
data (U_PDU) 2 bytes short. Moreover, if data is just 1-byte, TCP datagrams
receive TCP checksum error.
We have corrected that bug as shown below;
diff -rNu ethereal-0.99.0/epan/dissectors/packet-s5066.c
ethereal-0.99.0.patched/epan/dissectors/packet-s5066.c
--- ethereal-0.99.0/epan/dissectors/packet-s5066.c 2006-09-11
12:29:20.000000000 +0300
+++ ethereal-0.99.0.patched/epan/dissectors/packet-s5066.c 2006-09-11
12:31:04.000000000 +0300
@@ -1129,10 +1129,9 @@
proto_tree_add_item(tree, hf_s5066_25_tx_mode, tvb, offset, 1, FALSE);
proto_tree_add_item(tree, hf_s5066_25_src_sapid, tvb, offset, 1, FALSE);
offset++;
offset = dissect_s5066_address(tvb, offset, tree, TRUE);
- proto_tree_add_item(tree, hf_s5066_25_size, tvb, offset, 2, FALSE);
offset += 2;
d_pdu_size = tvb_get_ntohs(tvb, offset);
- proto_tree_add_item(tree, hf_s5066_21_size, tvb, offset, 2, FALSE);
offset += 2;
+ proto_tree_add_item(tree, hf_s5066_25_size, tvb, offset, 2, FALSE);
offset += 2;
/* Handle RockwellCollins (<= v2.1) 4-byte offset */
if ( (pdu_size - offset) == d_pdu_size + 4 ) {
Best regards,
Taner KURTULUS
Voice: +903124266789 / 2085
Fax: +903124284880
Mail: taner.kurtulus@xxxxxxxxxxxxxx
TUBITAK-UEKAE/G222 Software Development Division
http://g222.uekae.tubitak.gov.tr/
