On Tue, 1 Feb 2011, Lawrence Stewart wrote:
On 02/01/11 04:17, John Baldwin wrote:
Somewhat related fallout to the bug reported on security@ recently, I think
this KASSERT() in tcp_output() is bogus:
KASSERT(len + hdrlen + ipoptlen == m_length(m, NULL),
("%s: mbuf chain shorter than expected", __func__));
Specifically, just a few lines earlier in tcp_output() we set the packet
header length to just 'len + hdrlen':
/*
* Put TCP length in extended header, and then
* checksum extended header and data.
*/
m->m_pkthdr.len = hdrlen + len; /* in6_cksum() need this */
Also, the ipoptions are stored in a separate mbuf chain in the in pcb
(inp_options) that is passed as a separate argument to ip_output(). Given
that, I would think that m_length() should not reflect ipoptlen since it
should not include IP options in that chain?
There is some relevant prior discussion on src-committers@ for r212803
between Andre and Bjoern.
Yeah and I still have the temporary workaround from
http://p4web.freebsd.org/@@185095?ac=10
I think you are specifically refering to
http://lists.freebsd.org/pipermail/svn-src-head/2010-October/021814.html
I had been pinging people back then, but I am happy to see the
discussion about these TCP changes finally happing now. I'll have to
swap thing back in completly - it's been more than three months. Let
me see later today.
/bz
--
Bjoern A. Zeeb You have to have visions!
<ks> Going to jail sucks -- <bz> All my daemons like it!
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/jails.html
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