[NETNS]: Drop packets in the non-initial namespace on the per/protocol basis.

IP layer now can handle multiple namespaces normally. So, process such
packets normally and drop them only if the transport layer is not
aware about namespaces.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 6 insertions, 5 deletions

diff --git a/include/net/protocol.h b/include/net/protocol.h
index ad8c584233a6..8d024d7cb741 100644
--- a/include/net/protocol.h
+++ b/include/net/protocol.h
@@ -39,7 +39,8 @@ struct net_protocol {
         int                     (*gso_send_check)(struct sk_buff *skb);
         struct sk_buff         *(*gso_segment)(struct sk_buff *skb,
                                                int features);
-        int                     no_policy;
+        unsigned int            no_policy:1,
+                                netns_ok:1;
 };
 
 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index eb1fa27dc0c4..2aeea5d15425 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -199,6 +199,8 @@ int ip_call_ra_chain(struct sk_buff *skb)
 
 static int ip_local_deliver_finish(struct sk_buff *skb)
 {
+        struct net *net = skb->dev->nd_net;
+
         __skb_pull(skb, ip_hdrlen(skb));
 
         /* Point into the IP datagram, just past the header. */
@@ -214,7 +216,8 @@ static int ip_local_deliver_finish(struct sk_buff *skb)
                 raw = raw_local_deliver(skb, protocol);
 
                 hash = protocol & (MAX_INET_PROTOS - 1);
-                if ((ipprot = rcu_dereference(inet_protos[hash])) != NULL) {
+                ipprot = rcu_dereference(inet_protos[hash]);
+                if (ipprot != NULL && (net == &init_net || ipprot->netns_ok)) {
                         int ret;
 
                         if (!ipprot->no_policy) {
@@ -375,9 +378,6 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
         struct iphdr *iph;
         u32 len;
 
-        if (dev->nd_net != &init_net)
-                goto drop;
-
         /* When the interface is in promisc. mode, drop all the crap
          * that it receives, do not try to analyse it.
          */