[patch] Review: Fix Tahi "Redirected On-link" Test Case

[Eric van Gyzen]

Bjoern and net@:

I would appreciate your review and comments on the following patches.

http://vangyzen.net/FreeBSD/patches/redir_onlink_8_rev1.diff
http://vangyzen.net/FreeBSD/patches/redir_onlink_9_rev1.diff
http://vangyzen.net/FreeBSD/patches/redir_onlink_10_rev1.diff

Thanks in advance,

Eric

====

Fix the Redirected On-Link test cases in the Tahi IPv6 Ready Logo Phase 
2 test suite.

On receipt of a redirect message, install an interface route for the 
redirected destination.  On removal of the corresponding Neighbor Cache 
entry, remove the interface route.

This requires changes in rtredirect_fib() to cope with an AF_LINK 
address for the gateway and with the absence of RTF_GATEWAY.

Unrelated to the above, fix a recursion on the radix node head lock 
triggered by the Redirected to Alternate Router test cases.

All Section 2 (Neighbor Discovery) test cases pass on 10-CURRENT and 
9-STABLE.  (8-STABLE pending)

Other test cases:

* the RTF_MODIFIED case, with IPv4 and IPv6 (using a 
RTF_HOST|RTF_GATEWAY route for the destination)

* the redirected-to-self case, with IPv4 and IPv6

* a valid IPv4 redirect

All testing was done with WITNESS and INVARIANTS.

Submitted by:    Eric van Gyzen <eric % vangyzen : net>,
                             Mark Kelley <Mark.Kelley % compellent : com>,
                             Terence Telkamp <Terence_Telkamp % dell : com>
Sponsored by:    Dell, Inc.
PR:                        kern/152791