netlink: implement unbind to netlink_setsockopt NETLINK_DROP_MEMBERSHIP

Call the per-protocol unbind function rather than bind function on
NETLINK_DROP_MEMBERSHIP in netlink_setsockopt().

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7e8d229bc010..92f4b6915e89 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2129,7 +2129,7 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname,
                         return err;
                 if (!val || val - 1 >= nlk->ngroups)
                         return -EINVAL;
-                if (nlk->netlink_bind) {
+                if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) {
                         err = nlk->netlink_bind(val);
                         if (err)
                                 return err;
@@ -2138,6 +2138,8 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname,
                 netlink_update_socket_mc(nlk, val,
                                          optname == NETLINK_ADD_MEMBERSHIP);
                 netlink_table_ungrab();
+                if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind)
+                        nlk->netlink_unbind(val);
 
                 err = 0;
                 break;