[Babel-users] atomic updates and ipv6 cache flushing issues

[Juliusz Chroboczek]

> Robert bradley has been working on making atomic route updates work
> and possibly better route cache flushing.
[...]
> get the patchset from: git://github.com/rb12345/babeld.git

While it hasn't rained yet, I've looked at the code.

1. The commit "Atomic route modification in kernel_netlink" contains
both the atomic route modification code and code for flushing the
routing cache.  I'd like the two to be separated.  (I can do that if
you want, Robert, and leave your name as the original author of the
commit.)

2. When was NLM_F_REPLACE introduced?  Does it fail cleanly on older
kernels?  If so, the code should fall back to the non-atomic
implementation upon EEXIST.  If not, then this cannot go in -- a lot
of folks are running babeld on older embedded kernels.

3. What happens on older multipath kernels?  I fear that NLM_F_REPLACE
is just ignored, which would cause both routes to remain installed --
an explicit flush would then be needed.

4. Is the cache flushing still needed with Baptiste's patch?  I'd
rather not be tweaking /proc files at runtime.

-- Juliusz