On Tue, Oct 24, 2017 at 1:19 AM, Laszlo Toth wrote:
> Commit 9b9742022888 ("sctp: support ipv6 nonlocal bind")
> introduced support for the above options as v4 sctp did,
> so patched sctp_v6_available().
>
> In the v4 implementation it's enough, because
> sctp_inet_bind_verify() just returns with sctp_v4_available().
> However sctp_inet6_bind_verify() has an extra check before that
> for link-local scope_id, which won't respect the above options.
>
> Added the checks before calling ipv6_chk_addr(), but
> not before the validation of scope_id.
>
> before (w/ both options):
> ./v6test fe80::10 sctp
> bind failed, errno: 99 (Cannot assign requested address)
> ./v6test fe80::10 tcp
> bind success, errno: 0 (Success)
>
> after (w/ both options):
> ./v6test fe80::10 sctp
> bind success, errno: 0 (Success)
>
> Signed-off-by: Laszlo Toth
> ---
> changed in v2:
> - fixed indentation
>
> net/sctp/ipv6.c | 6 --
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
> index 51c4887..7fe9e1d1 100644
> --- a/net/sctp/ipv6.c
> +++ b/net/sctp/ipv6.c
> @@ -882,8 +882,10 @@ static int sctp_inet6_bind_verify(struct sctp_sock *opt,
> union sctp_addr *addr)
> net = sock_net(&opt->inet.sk);
> rcu_read_lock();
> dev = dev_get_by_index_rcu(net,
> addr->v6.sin6_scope_id);
> - if (!dev ||
> - !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0))
> {
> + if (!dev || !(opt->inet.freebind ||
> + net->ipv6.sysctl.ip_nonlocal_bind ||
> + ipv6_chk_addr(net, &addr->v6.sin6_addr,
> + dev, 0))) {
> rcu_read_unlock();
> return 0;
> }
> --
> 2.7.4
>
Reviewed-by: Xin Long
Thanks.