http://anonsvn.wireshark.org/viewvc/viewvc.cgi?view=rev&revision=50085
User: alagoutte
Date: 2013/06/20 01:17 PM
Log:
From report of Alexander Okonnikov and Patch of Matt Texier via https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=8802 Incorrect decoding of Layer2 Info Extended Community
Within BGP Update message for BGP VPLS (RFC 4761) some parts of Extended Community "Layer2 Info" are incorrectly decoded:
1. Encapsulation - Unknown (0x13). Per RFC 4761 encap type 0x13 is "VPLS" (clause 3.2.4);
2. Control Flags - per RFC 4761 (clause 3.2.4) two least-significant bits (6 and 7) are defined as:
"C" (bit 6, Control Word): value 1 - Control Word is required - and value 0 - Control Word is not required; decoding is correct (at least for value 0);
"S" (bit 7, Sequence delivery): value 1 - Sequence delivery is required - and value 0 - Sequence delivery is not required; decoding is incorrect, because for value 0 (sequence delivery is not required) you provide description that "Sequence delivery is required".
Also, there is description (at the same string) "F Flag (reserved) set. IETF document draft-ietf-l2vpn-vpls-multihoming (clause 3.3.1) updates RFC 4761 and defines two additional bits within Control Flags byte - D (bit 0, "Down") and F (bit 2, "Flush"). You provide description that "F Flag (reserved) set" when this flag actually is not set (value 0). Furthermore, you don't provide description about status of flag D (in attached dump in the first packet flag D is set and unset in the second packet).
Directory: /trunk/epan/dissectors/
Changes Path Action
+78 -30 packet-bgp.c Modified