Initial import

1 files changed, 292 insertions, 0 deletions

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
new file mode 100644
index 000000000..e97572b5d
--- /dev/null
+++ b/net/bridge/br_forward.c
@@ -0,0 +1,292 @@
+/*
+ *	Forwarding decision
+ *	Linux ethernet bridge
+ *
+ *	Authors:
+ *	Lennert Buytenhek		<buytenh@gnu.org>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/netpoll.h>
+#include <linux/skbuff.h>
+#include <linux/if_vlan.h>
+#include <linux/netfilter_bridge.h>
+#include "br_private.h"
+
+static int deliver_clone(const struct net_bridge_port *prev,
+			 struct sk_buff *skb,
+			 void (*__packet_hook)(const struct net_bridge_port *p,
+					       struct sk_buff *skb));
+
+/* Don't forward packets to originating port or forwarding disabled */
+static inline int should_deliver(const struct net_bridge_port *p,
+				 const struct sk_buff *skb)
+{
+	return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
+		br_allowed_egress(p->br, nbp_get_vlan_info(p), skb) &&
+		p->state == BR_STATE_FORWARDING;
+}
+
+int br_dev_queue_push_xmit(struct sock *sk, struct sk_buff *skb)
+{
+	if (!is_skb_forwardable(skb->dev, skb)) {
+		kfree_skb(skb);
+	} else {
+		skb_push(skb, ETH_HLEN);
+		br_drop_fake_rtable(skb);
+		dev_queue_xmit(skb);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
+
+int br_forward_finish(struct sock *sk, struct sk_buff *skb)
+{
+	return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, sk, skb,
+		       NULL, skb->dev,
+		       br_dev_queue_push_xmit);
+
+}
+EXPORT_SYMBOL_GPL(br_forward_finish);
+
+static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
+{
+	skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb);
+	if (!skb)
+		return;
+
+	skb->dev = to->dev;
+
+	if (unlikely(netpoll_tx_running(to->br->dev))) {
+		if (!is_skb_forwardable(skb->dev, skb))
+			kfree_skb(skb);
+		else {
+			skb_push(skb, ETH_HLEN);
+			br_netpoll_send_skb(to, skb);
+		}
+		return;
+	}
+
+	NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, NULL, skb,
+		NULL, skb->dev,
+		br_forward_finish);
+}
+
+static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
+{
+	struct net_device *indev;
+
+	if (skb_warn_if_lro(skb)) {
+		kfree_skb(skb);
+		return;
+	}
+
+	skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb);
+	if (!skb)
+		return;
+
+	indev = skb->dev;
+	skb->dev = to->dev;
+	skb_forward_csum(skb);
+
+	NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, NULL, skb,
+		indev, skb->dev,
+		br_forward_finish);
+}
+
+/* called with rcu_read_lock */
+void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
+{
+	if (to && should_deliver(to, skb)) {
+		__br_deliver(to, skb);
+		return;
+	}
+
+	kfree_skb(skb);
+}
+EXPORT_SYMBOL_GPL(br_deliver);
+
+/* called with rcu_read_lock */
+void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
+{
+	if (should_deliver(to, skb)) {
+		if (skb0)
+			deliver_clone(to, skb, __br_forward);
+		else
+			__br_forward(to, skb);
+		return;
+	}
+
+	if (!skb0)
+		kfree_skb(skb);
+}
+
+static int deliver_clone(const struct net_bridge_port *prev,
+			 struct sk_buff *skb,
+			 void (*__packet_hook)(const struct net_bridge_port *p,
+					       struct sk_buff *skb))
+{
+	struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
+
+	skb = skb_clone(skb, GFP_ATOMIC);
+	if (!skb) {
+		dev->stats.tx_dropped++;
+		return -ENOMEM;
+	}
+
+	__packet_hook(prev, skb);
+	return 0;
+}
+
+static struct net_bridge_port *maybe_deliver(
+	struct net_bridge_port *prev, struct net_bridge_port *p,
+	struct sk_buff *skb,
+	void (*__packet_hook)(const struct net_bridge_port *p,
+			      struct sk_buff *skb))
+{
+	int err;
+
+	if (!should_deliver(p, skb))
+		return prev;
+
+	if (!prev)
+		goto out;
+
+	err = deliver_clone(prev, skb, __packet_hook);
+	if (err)
+		return ERR_PTR(err);
+
+out:
+	return p;
+}
+
+/* called under bridge lock */
+static void br_flood(struct net_bridge *br, struct sk_buff *skb,
+		     struct sk_buff *skb0,
+		     void (*__packet_hook)(const struct net_bridge_port *p,
+					   struct sk_buff *skb),
+		     bool unicast)
+{
+	struct net_bridge_port *p;
+	struct net_bridge_port *prev;
+
+	prev = NULL;
+
+	list_for_each_entry_rcu(p, &br->port_list, list) {
+		/* Do not flood unicast traffic to ports that turn it off */
+		if (unicast && !(p->flags & BR_FLOOD))
+			continue;
+
+		/* Do not flood to ports that enable proxy ARP */
+		if (p->flags & BR_PROXYARP)
+			continue;
+		if ((p->flags & BR_PROXYARP_WIFI) &&
+		    BR_INPUT_SKB_CB(skb)->proxyarp_replied)
+			continue;
+
+		prev = maybe_deliver(prev, p, skb, __packet_hook);
+		if (IS_ERR(prev))
+			goto out;
+	}
+
+	if (!prev)
+		goto out;
+
+	if (skb0)
+		deliver_clone(prev, skb, __packet_hook);
+	else
+		__packet_hook(prev, skb);
+	return;
+
+out:
+	if (!skb0)
+		kfree_skb(skb);
+}
+
+
+/* called with rcu_read_lock */
+void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast)
+{
+	br_flood(br, skb, NULL, __br_deliver, unicast);
+}
+
+/* called under bridge lock */
+void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
+		      struct sk_buff *skb2, bool unicast)
+{
+	br_flood(br, skb, skb2, __br_forward, unicast);
+}
+
+#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
+/* called with rcu_read_lock */
+static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
+			       struct sk_buff *skb, struct sk_buff *skb0,
+			       void (*__packet_hook)(
+					const struct net_bridge_port *p,
+					struct sk_buff *skb))
+{
+	struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
+	struct net_bridge *br = netdev_priv(dev);
+	struct net_bridge_port *prev = NULL;
+	struct net_bridge_port_group *p;
+	struct hlist_node *rp;
+
+	rp = rcu_dereference(hlist_first_rcu(&br->router_list));
+	p = mdst ? rcu_dereference(mdst->ports) : NULL;
+	while (p || rp) {
+		struct net_bridge_port *port, *lport, *rport;
+
+		lport = p ? p->port : NULL;
+		rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
+			     NULL;
+
+		port = (unsigned long)lport > (unsigned long)rport ?
+		       lport : rport;
+
+		prev = maybe_deliver(prev, port, skb, __packet_hook);
+		if (IS_ERR(prev))
+			goto out;
+
+		if ((unsigned long)lport >= (unsigned long)port)
+			p = rcu_dereference(p->next);
+		if ((unsigned long)rport >= (unsigned long)port)
+			rp = rcu_dereference(hlist_next_rcu(rp));
+	}
+
+	if (!prev)
+		goto out;
+
+	if (skb0)
+		deliver_clone(prev, skb, __packet_hook);
+	else
+		__packet_hook(prev, skb);
+	return;
+
+out:
+	if (!skb0)
+		kfree_skb(skb);
+}
+
+/* called with rcu_read_lock */
+void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
+			  struct sk_buff *skb)
+{
+	br_multicast_flood(mdst, skb, NULL, __br_deliver);
+}
+
+/* called with rcu_read_lock */
+void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
+			  struct sk_buff *skb, struct sk_buff *skb2)
+{
+	br_multicast_flood(mdst, skb, skb2, __br_forward);
+}
+#endif