Add bounds checking to IPv6 extension header parsing loop

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Currently there is no bounds checking and a traceback will occur if the packet 
data is shorter than the purported extension header option length.

FWIW, I'm not using this exact diff in my project.  Instead of raising 
dpkt.UnpackError, I am just silently breaking out of the loop.  That way most 
of the pertinent IPv6 data (up and to including the bad extension header) is 
successfully parsed out of the packet and accessible, as opposed to having only 
the Ethernet portion.  That said, I felt raising the error fit better with the 
existing code.  If the maintainers disagree then feel free to change this.

Original issue reported on code.google.com by aa...@monkey.org on 25 Apr 2011 at 1:12

Attachments:

• dpkt-ipv6-bounds-check.diff