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Bug in libnet_build_ipv6?

from [cnelson] Network Security [Permanent Link]
Subject: Bug in libnet_build_ipv6?
Date: Tue, 07 Sep 2004 12:08:29 -0400 
I've downloaded libnet 1.1.2.1 and looking at libnet_build_ip.c, I think I see 
a bug.  Mind you, I'm fairly new to this area so I believe it's as likely I'm 
wrong as the code but I'd appreciate feedback either way.

I'm looking at IPv6 header creation in  libnet_build_ipv6().  Lines 490-491 say:

    ip_hdr.ip_flags[0] = 0x06 << 4;
    ip_hdr.ip_flags[1] = ((tc & 0x0F) << 4) | ((fl & 0xF0000) >> 16);

but page 3 of RFC 2460 (http://www.ietf.org/rfc/rfc2460.txt) shows:

   3.  IPv6 Header Format

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Version| Traffic Class |           Flow Label                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Payload Length        |  Next Header  |   Hop Limit   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

and http://www.networksorcery.com/enp/protocol/ipv6.htm confirms:

   Version. 4 bits.
   IPv6 version number.

   Traffic Class. 8 bits.
   Internet traffic priority delivery value.

So isn't libnet_build_ipv6() wrong?  Shouldn't lines 490-491 read something 
like:

    ip_hdr.ip_flags[0] = (0x06 << 4) | ((tc & 0xF0) >> 4)
    ip_hdr.ip_flags[1] = ((tc & 0x0F) << 4) | ((fl & 0xF0000) >> 16);

                                  Chris
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