netfilter: Pass net into okfn

This is immediately motivated by the bridge code that chains functions that
call into netfilter.  Without passing net into the okfns the bridge code would
need to guess about the best expression for the network namespace to process
packets in.

As net is frequently one of the first things computed in continuation functions
after netfilter has done it's job passing in the desired network namespace is in
many cases a code simplification.

To support this change the function dst_output_okfn is introduced to
simplify passing dst_output as an okfn.  For the moment dst_output_okfn
just silently drops the struct net.

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

1 files changed, 3 insertions, 4 deletions

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index ae71e9ade5f9..61ff5ea31283 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -621,7 +621,7 @@ out:
 }
 EXPORT_SYMBOL(arp_create);
 
-static int arp_xmit_finish(struct sock *sk, struct sk_buff *skb)
+static int arp_xmit_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
         return dev_queue_xmit(skb);
 }
@@ -642,7 +642,7 @@ EXPORT_SYMBOL(arp_xmit);
  *      Process an arp request.
  */
 
-static int arp_process(struct sock *sk, struct sk_buff *skb)
+static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
         struct net_device *dev = skb->dev;
         struct in_device *in_dev = __in_dev_get_rcu(dev);
@@ -654,7 +654,6 @@ static int arp_process(struct sock *sk, struct sk_buff *skb)
         u16 dev_type = dev->type;
         int addr_type;
         struct neighbour *n;
-        struct net *net = dev_net(dev);
         bool is_garp = false;
 
         /* arp_rcv below verifies the ARP header and verifies the device
@@ -865,7 +864,7 @@ out:
 
 static void parp_redo(struct sk_buff *skb)
 {
-        arp_process(NULL, skb);
+        arp_process(dev_net(skb->dev), NULL, skb);
 }