openvswitch: Add support for network namespaces.

Following patch adds support for network namespace to openvswitch.
Since it must release devices when namespaces are destroyed, a
side effect of this patch is that the module no longer keeps a
refcount but instead cleans up any state when it is unloaded.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

net/openvswitch/datapath.h

@@ -27,8 +27,7 @@
 #include <linux/u64_stats_sync.h>
 
 #include "flow.h"
-
-struct vport;
+#include "vport.h"
 
 #define DP_MAX_PORTS 1024
 #define SAMPLE_ACTION_DEPTH 3
@@ -63,6 +62,7 @@ struct dp_stats_percpu {
  * @port_list: List of all ports in @ports in arbitrary order.  RTNL required
  * to iterate or modify.
  * @stats_percpu: Per-CPU datapath statistics.
+ * @net: Reference to net namespace.
  *
  * Context: See the comment on locking at the top of datapath.c for additional
  * locking information.
@@ -80,6 +80,11 @@ struct datapath {
 
 	/* Stats. */
 	struct dp_stats_percpu __percpu *stats_percpu;
+
+#ifdef CONFIG_NET_NS
+	/* Network namespace ref. */
+	struct net *net;
+#endif
 };
 
 /**
@@ -108,6 +113,16 @@ struct dp_upcall_info {
 	u32 pid;
 };
 
+static inline struct net *ovs_dp_get_net(struct datapath *dp)
+{
+	return read_pnet(&dp->net);
+}
+
+static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
+{
+	write_pnet(&dp->net, net);
+}
+
 extern struct notifier_block ovs_dp_device_notifier;
 extern struct genl_multicast_group ovs_dp_vport_multicast_group;
 

net/openvswitch/dp_notify.c

@@ -41,18 +41,20 @@ static int dp_device_event(struct notifier_block *unused, unsigned long event,
 	case NETDEV_UNREGISTER:
 		if (!ovs_is_internal_dev(dev)) {
 			struct sk_buff *notify;
+			struct datapath *dp = vport->dp;
 
 			notify = ovs_vport_cmd_build_info(vport, 0, 0,
 							  OVS_VPORT_CMD_DEL);
 			ovs_dp_detach_port(vport);
 			if (IS_ERR(notify)) {
-				netlink_set_err(init_net.genl_sock, 0,
+				netlink_set_err(ovs_dp_get_net(dp)->genl_sock, 0,
 						ovs_dp_vport_multicast_group.id,
 						PTR_ERR(notify));
 				break;
 			}
 
-			genlmsg_multicast(notify, 0, ovs_dp_vport_multicast_group.id,
+			genlmsg_multicast_netns(ovs_dp_get_net(dp), notify, 0,
+						ovs_dp_vport_multicast_group.id,
 						GFP_KERNEL);
 		}
 		break;

net/openvswitch/vport-internal_dev.c

@@ -175,9 +175,14 @@ static struct vport *internal_dev_create(const struct vport_parms *parms)
 		goto error_free_vport;
 	}
 
+	dev_net_set(netdev_vport->dev, ovs_dp_get_net(vport->dp));
 	internal_dev = internal_dev_priv(netdev_vport->dev);
 	internal_dev->vport = vport;
 
+	/* Restrict bridge port to current netns. */
+	if (vport->port_no == OVSP_LOCAL)
+		netdev_vport->dev->features |= NETIF_F_NETNS_LOCAL;
+
 	err = register_netdevice(netdev_vport->dev);
 	if (err)
 		goto error_free_netdev;

net/openvswitch/vport-netdev.c

@@ -83,7 +83,7 @@ static struct vport *netdev_create(const struct vport_parms *parms)
 
 	netdev_vport = netdev_vport_priv(vport);
 
-	netdev_vport->dev = dev_get_by_name(&init_net, parms->name);
+	netdev_vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), parms->name);
 	if (!netdev_vport->dev) {
 		err = -ENODEV;
 		goto error_free_vport;

net/openvswitch/vport.c

@@ -16,10 +16,10 @@
  * 02110-1301, USA
  */
 
-#include <linux/dcache.h>
 #include <linux/etherdevice.h>
 #include <linux/if.h>
 #include <linux/if_vlan.h>
+#include <linux/jhash.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
@@ -27,7 +27,9 @@
 #include <linux/rcupdate.h>
 #include <linux/rtnetlink.h>
 #include <linux/compat.h>
+#include <net/net_namespace.h>
 
+#include "datapath.h"
 #include "vport.h"
 #include "vport-internal_dev.h"
 
@@ -67,9 +69,9 @@ void ovs_vport_exit(void)
 	kfree(dev_table);
 }
 
-static struct hlist_head *hash_bucket(const char *name)
+static struct hlist_head *hash_bucket(struct net *net, const char *name)
 {
-	unsigned int hash = full_name_hash(name, strlen(name));
+	unsigned int hash = jhash(name, strlen(name), (unsigned long) net);
 	return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
 }
 
@@ -80,14 +82,15 @@ static struct hlist_head *hash_bucket(const char *name)
  *
  * Must be called with RTNL or RCU read lock.
  */
-struct vport *ovs_vport_locate(const char *name)
+struct vport *ovs_vport_locate(struct net *net, const char *name)
 {
-	struct hlist_head *bucket = hash_bucket(name);
+	struct hlist_head *bucket = hash_bucket(net, name);
 	struct vport *vport;
 	struct hlist_node *node;
 
 	hlist_for_each_entry_rcu(vport, node, bucket, hash_node)
-		if (!strcmp(name, vport->ops->get_name(vport)))
+		if (!strcmp(name, vport->ops->get_name(vport)) &&
+		    net_eq(ovs_dp_get_net(vport->dp), net))
 			return vport;
 
 	return NULL;
@@ -170,14 +173,17 @@ struct vport *ovs_vport_add(const struct vport_parms *parms)
 
 	for (i = 0; i < ARRAY_SIZE(vport_ops_list); i++) {
 		if (vport_ops_list[i]->type == parms->type) {
+			struct hlist_head *bucket;
+
 			vport = vport_ops_list[i]->create(parms);
 			if (IS_ERR(vport)) {
 				err = PTR_ERR(vport);
 				goto out;
 			}
 
-			hlist_add_head_rcu(&vport->hash_node,
-					   hash_bucket(vport->ops->get_name(vport)));
+			bucket = hash_bucket(ovs_dp_get_net(vport->dp),
+					     vport->ops->get_name(vport));
+			hlist_add_head_rcu(&vport->hash_node, bucket);
 			return vport;
 		}
 	}

net/openvswitch/vport.h

@@ -20,6 +20,7 @@
 #define VPORT_H 1
 
 #include <linux/list.h>
+#include <linux/netlink.h>
 #include <linux/openvswitch.h>
 #include <linux/skbuff.h>
 #include <linux/spinlock.h>
@@ -38,7 +39,7 @@ void ovs_vport_exit(void);
 struct vport *ovs_vport_add(const struct vport_parms *);
 void ovs_vport_del(struct vport *);
 
-struct vport *ovs_vport_locate(const char *name);
+struct vport *ovs_vport_locate(struct net *net, const char *name);
 
 void ovs_vport_get_stats(struct vport *, struct ovs_vport_stats *);