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>

6 files changed, 21 insertions, 24 deletions

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 2dd2a23ce707..48afca729ed7 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -35,7 +35,7 @@ static inline int should_deliver(const struct net_bridge_port *p,
 		p->state == BR_STATE_FORWARDING;
 }
 
-int br_dev_queue_push_xmit(struct sock *sk, struct sk_buff *skb)
+int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	if (!is_skb_forwardable(skb->dev, skb))
 		goto drop;
@@ -65,9 +65,8 @@ drop:
 }
 EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
 
-int br_forward_finish(struct sock *sk, struct sk_buff *skb)
+int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
-	struct net *net = dev_net(skb->dev);
 	return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING,
 		       net, sk, skb, NULL, skb->dev,
 		       br_dev_queue_push_xmit);
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 78fa7acd836e..223f4040d9df 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -26,7 +26,8 @@
 br_should_route_hook_t __rcu *br_should_route_hook __read_mostly;
 EXPORT_SYMBOL(br_should_route_hook);
 
-static int br_netif_receive_skb(struct sock *sk, struct sk_buff *skb)
+static int
+br_netif_receive_skb(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	return netif_receive_skb(skb);
 }
@@ -125,7 +126,7 @@ static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br,
 }
 
 /* note: already called with rcu_read_lock */
-int br_handle_frame_finish(struct sock *sk, struct sk_buff *skb)
+int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	const unsigned char *dest = eth_hdr(skb)->h_dest;
 	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
@@ -213,7 +214,7 @@ drop:
 EXPORT_SYMBOL_GPL(br_handle_frame_finish);
 
 /* note: already called with rcu_read_lock */
-static int br_handle_local_finish(struct sock *sk, struct sk_buff *skb)
+static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
 	u16 vid = 0;
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index 7886c9d7e23d..e6e76bbdc82f 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -256,7 +256,7 @@ void nf_bridge_update_protocol(struct sk_buff *skb)
  * don't, we use the neighbour framework to find out. In both cases, we make
  * sure that br_handle_frame_finish() is called afterwards.
  */
-int br_nf_pre_routing_finish_bridge(struct sock *sk, struct sk_buff *skb)
+int br_nf_pre_routing_finish_bridge(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	struct neighbour *neigh;
 	struct dst_entry *dst;
@@ -273,7 +273,7 @@ int br_nf_pre_routing_finish_bridge(struct sock *sk, struct sk_buff *skb)
 		if (neigh->hh.hh_len) {
 			neigh_hh_bridge(&neigh->hh, skb);
 			skb->dev = nf_bridge->physindev;
-			ret = br_handle_frame_finish(sk, skb);
+			ret = br_handle_frame_finish(net, sk, skb);
 		} else {
 			/* the neighbour function below overwrites the complete
 			 * MAC header, so we save the Ethernet source address and
@@ -342,11 +342,10 @@ br_nf_ipv4_daddr_was_changed(const struct sk_buff *skb,
  * device, we proceed as if ip_route_input() succeeded. If it differs from the
  * logical bridge port or if ip_route_output_key() fails we drop the packet.
  */
-static int br_nf_pre_routing_finish(struct sock *sk, struct sk_buff *skb)
+static int br_nf_pre_routing_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	struct net_device *dev = skb->dev;
 	struct iphdr *iph = ip_hdr(skb);
-	struct net *net = dev_net(dev);
 	struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
 	struct rtable *rt;
 	int err;
@@ -536,10 +535,9 @@ static unsigned int br_nf_local_in(const struct nf_hook_ops *ops,
 }
 
 /* PF_BRIDGE/FORWARD *************************************************/
-static int br_nf_forward_finish(struct sock *sk, struct sk_buff *skb)
+static int br_nf_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
-	struct net *net = dev_net(skb->dev);
 	struct net_device *in;
 
 	if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) {
@@ -692,7 +690,7 @@ static int br_nf_push_frag_xmit(struct net *net, struct sock *sk, struct sk_buff
 	__skb_push(skb, data->encap_size);
 
 	nf_bridge_info_free(skb);
-	return br_dev_queue_push_xmit(sk, skb);
+	return br_dev_queue_push_xmit(net, sk, skb);
 }
 static int br_nf_push_frag_xmit_sk(struct sock *sk, struct sk_buff *skb)
 {
@@ -728,17 +726,16 @@ static unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
 	return 0;
 }
 
-static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb)
+static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	struct nf_bridge_info *nf_bridge;
 	unsigned int mtu_reserved;
-	struct net *net = dev_net(skb_dst(skb)->dev);
 
 	mtu_reserved = nf_bridge_mtu_reduction(skb);
 
 	if (skb_is_gso(skb) || skb->len + mtu_reserved <= skb->dev->mtu) {
 		nf_bridge_info_free(skb);
-		return br_dev_queue_push_xmit(sk, skb);
+		return br_dev_queue_push_xmit(net, sk, skb);
 	}
 
 	nf_bridge = nf_bridge_info_get(skb);
@@ -797,7 +794,7 @@ static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb)
 	}
 #endif
 	nf_bridge_info_free(skb);
-	return br_dev_queue_push_xmit(sk, skb);
+	return br_dev_queue_push_xmit(net, sk, skb);
  drop:
 	kfree_skb(skb);
 	return 0;
@@ -887,7 +884,7 @@ static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb)
 	skb->dev = nf_bridge->physindev;
 
 	nf_bridge->physoutdev = NULL;
-	br_handle_frame_finish(NULL, skb);
+	br_handle_frame_finish(dev_net(skb->dev), NULL, skb);
 }
 
 static int br_nf_dev_xmit(struct sk_buff *skb)
diff --git a/net/bridge/br_netfilter_ipv6.c b/net/bridge/br_netfilter_ipv6.c
index 5d19361ad5d3..e4dbbe44c724 100644
--- a/net/bridge/br_netfilter_ipv6.c
+++ b/net/bridge/br_netfilter_ipv6.c
@@ -161,12 +161,11 @@ br_nf_ipv6_daddr_was_changed(const struct sk_buff *skb,
  * for br_nf_pre_routing_finish(), same logic is used here but
  * equivalent IPv6 function ip6_route_input() called indirectly.
  */
-static int br_nf_pre_routing_finish_ipv6(struct sock *sk, struct sk_buff *skb)
+static int br_nf_pre_routing_finish_ipv6(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
 	struct rtable *rt;
 	struct net_device *dev = skb->dev;
-	struct net *net = dev_net(dev);
 	const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
 
 	nf_bridge->frag_max_size = IP6CB(skb)->frag_max_size;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 213baf7aaa93..74e99c75c8e4 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -413,10 +413,10 @@ int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
 
 /* br_forward.c */
 void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb);
-int br_dev_queue_push_xmit(struct sock *sk, struct sk_buff *skb);
+int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb);
 void br_forward(const struct net_bridge_port *to,
 		struct sk_buff *skb, struct sk_buff *skb0);
-int br_forward_finish(struct sock *sk, struct sk_buff *skb);
+int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
 void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast);
 void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
 		      struct sk_buff *skb2, bool unicast);
@@ -434,7 +434,7 @@ void br_port_flags_change(struct net_bridge_port *port, unsigned long mask);
 void br_manage_promisc(struct net_bridge *br);
 
 /* br_input.c */
-int br_handle_frame_finish(struct sock *sk, struct sk_buff *skb);
+int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
 rx_handler_result_t br_handle_frame(struct sk_buff **pskb);
 
 static inline bool br_rx_handler_check_rcu(const struct net_device *dev)
diff --git a/net/bridge/br_stp_bpdu.c b/net/bridge/br_stp_bpdu.c
index 8e2e8c352198..5881fbc114a9 100644
--- a/net/bridge/br_stp_bpdu.c
+++ b/net/bridge/br_stp_bpdu.c
@@ -30,7 +30,8 @@
 
 #define LLC_RESERVE sizeof(struct llc_pdu_un)
 
-static int br_send_bpdu_finish(struct sock *sk, struct sk_buff *skb)
+static int br_send_bpdu_finish(struct net *net, struct sock *sk,
+			       struct sk_buff *skb)
 {
 	return dev_queue_xmit(skb);
 }