Re: [PATCH v4 net] ipvs: fix bind to link-local mcast IPv6 address in backup

On Fri, Jun 17, 2016 at 09:42:49AM +0300, Julian Anastasov wrote:

	Hello,

On Thu, 16 Jun 2016, Quentin Armitage wrote:

quoted

When using HEAD from
https://git.kernel.org/cgit/utils/kernel/ipvsadm/ipvsadm.git/,
the command:
ipvsadm --start-daemon backup --mcast-interface eth0.60 \
    --mcast-group ff02::1:81
fails with the error message:
Argument list too long

whereas both:
ipvsadm --start-daemon master --mcast-interface eth0.60 \
    --mcast-group ff02::1:81
and:
ipvsadm --start-daemon backup --mcast-interface eth0.60 \
    --mcast-group 224.0.0.81
are successful.

The error message "Argument list too long" isn't helpful. The error occurs
because an IPv6 address is given in backup mode.

The error is in make_receive_sock() in net/netfilter/ipvs/ip_vs_sync.c,
since it fails to set the interface on the address or the socket before
calling inet6_bind() (via sock->ops->bind), where the test
'if (!sk->sk_bound_dev_if)' failed.

Setting sock->sk->sk_bound_dev_if on the socket before calling
inet6_bind() resolves the issue.

Fixes: d33288172e72 ("ipvs: add more mcast parameters for the sync daemon")
Signed-off-by: Quentin Armitage <redacted>

	Looks good to me, thanks!

Acked-by: Julian Anastasov <ja@ssi.bg>

	Simon, please apply to ipvs tree. Patch compiles
also on stable 4.4.13, 4.5.7 and 4.6.2, so no need for
special versions. The ack is also for the other 3 patches
from v4 (for ipvs-next) but they depend on this patch.

Thanks, done.