[NET]: Make packet reception network namespace safe

This patch modifies every packet receive function
registered with dev_add_pack() to drop packets if they
are not from the initial network namespace.

This should ensure that the various network stacks do
not receive packets in a anything but the initial network
namespace until the code has been converted and is ready
for them.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 766b5faaed21..cae1ee4f2ad6 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -252,6 +252,9 @@ static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,  struct
         struct sock *sk;
         struct sockaddr_pkt *spkt;
 
+        if (dev->nd_net != &init_net)
+                goto out;
+
         /*
          *      When we registered the protocol we saved the socket in the data
          *      field for just this event.
@@ -452,6 +455,9 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, struct packet
         int skb_len = skb->len;
         unsigned int snaplen, res;
 
+        if (dev->nd_net != &init_net)
+                goto drop;
+
         if (skb->pkt_type == PACKET_LOOPBACK)
                 goto drop;
 
@@ -568,6 +574,9 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
         struct sk_buff *copy_skb = NULL;
         struct timeval tv;
 
+        if (dev->nd_net != &init_net)
+                goto drop;
+
         if (skb->pkt_type == PACKET_LOOPBACK)
                 goto drop;