ipvs: prevent mixing heterogeneous pools and synchronization

The synchronization protocol is not compatible with heterogeneous pools, so
we need to verify that we're not turning both on at the same time.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 15 insertions, 0 deletions

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 6bd2cc682137..462760eded94 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -779,6 +779,12 @@ __ip_vs_update_dest(struct ip_vs_service *svc, struct ip_vs_dest *dest,
         struct ip_vs_scheduler *sched;
         int conn_flags;
 
+        /* We cannot modify an address and change the address family */
+        BUG_ON(!add && udest->af != dest->af);
+
+        if (add && udest->af != svc->af)
+                ipvs->mixed_address_family_dests++;
+
         /* set the weight and the flags */
         atomic_set(&dest->weight, udest->weight);
         conn_flags = udest->conn_flags & IP_VS_CONN_F_DEST_MASK;
@@ -1061,6 +1067,9 @@ static void __ip_vs_unlink_dest(struct ip_vs_service *svc,
         list_del_rcu(&dest->n_list);
         svc->num_dests--;
 
+        if (dest->af != svc->af)
+                net_ipvs(svc->net)->mixed_address_family_dests--;
+
         if (svcupd) {
                 struct ip_vs_scheduler *sched;
 
@@ -3256,6 +3265,12 @@ static int ip_vs_genl_new_daemon(struct net *net, struct nlattr **attrs)
               attrs[IPVS_DAEMON_ATTR_SYNC_ID]))
                 return -EINVAL;
 
+        /* The synchronization protocol is incompatible with mixed family
+         * services
+         */
+        if (net_ipvs(net)->mixed_address_family_dests > 0)
+                return -EINVAL;
+
         return start_sync_thread(net,
                                  nla_get_u32(attrs[IPVS_DAEMON_ATTR_STATE]),
                                  nla_data(attrs[IPVS_DAEMON_ATTR_MCAST_IFN]),