net: Add Open vSwitch kernel components.

Open vSwitch is a multilayer Ethernet switch targeted at virtualized
environments.  In addition to supporting a variety of features
expected in a traditional hardware switch, it enables fine-grained
programmatic extension and flow-based control of the network.
This control is useful in a wide variety of applications but is
particularly important in multi-server virtualization deployments,
which are often characterized by highly dynamic endpoints and the need
to maintain logical abstractions for multiple tenants.

The Open vSwitch datapath provides an in-kernel fast path for packet
forwarding.  It is complemented by a userspace daemon, ovs-vswitchd,
which is able to accept configuration from a variety of sources and
translate it into packet processing rules.

See http://openvswitch.org for more information and userspace
utilities.

Signed-off-by: Jesse Gross <jesse@nicira.com>
diff --git a/net/openvswitch/flow.h b/net/openvswitch/flow.h
new file mode 100644
index 0000000..2747dc2
--- /dev/null
+++ b/net/openvswitch/flow.h
@@ -0,0 +1,199 @@
+/*
+ * Copyright (c) 2007-2011 Nicira Networks.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ */
+
+#ifndef FLOW_H
+#define FLOW_H 1
+
+#include <linux/kernel.h>
+#include <linux/netlink.h>
+#include <linux/openvswitch.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/rcupdate.h>
+#include <linux/if_ether.h>
+#include <linux/in6.h>
+#include <linux/jiffies.h>
+#include <linux/time.h>
+#include <linux/flex_array.h>
+#include <net/inet_ecn.h>
+
+struct sk_buff;
+
+struct sw_flow_actions {
+	struct rcu_head rcu;
+	u32 actions_len;
+	struct nlattr actions[];
+};
+
+struct sw_flow_key {
+	struct {
+		u32	priority;	/* Packet QoS priority. */
+		u16	in_port;	/* Input switch port (or USHRT_MAX). */
+	} phy;
+	struct {
+		u8     src[ETH_ALEN];	/* Ethernet source address. */
+		u8     dst[ETH_ALEN];	/* Ethernet destination address. */
+		__be16 tci;		/* 0 if no VLAN, VLAN_TAG_PRESENT set otherwise. */
+		__be16 type;		/* Ethernet frame type. */
+	} eth;
+	struct {
+		u8     proto;		/* IP protocol or lower 8 bits of ARP opcode. */
+		u8     tos;		/* IP ToS. */
+		u8     ttl;		/* IP TTL/hop limit. */
+		u8     frag;		/* One of OVS_FRAG_TYPE_*. */
+	} ip;
+	union {
+		struct {
+			struct {
+				__be32 src;	/* IP source address. */
+				__be32 dst;	/* IP destination address. */
+			} addr;
+			union {
+				struct {
+					__be16 src;		/* TCP/UDP source port. */
+					__be16 dst;		/* TCP/UDP destination port. */
+				} tp;
+				struct {
+					u8 sha[ETH_ALEN];	/* ARP source hardware address. */
+					u8 tha[ETH_ALEN];	/* ARP target hardware address. */
+				} arp;
+			};
+		} ipv4;
+		struct {
+			struct {
+				struct in6_addr src;	/* IPv6 source address. */
+				struct in6_addr dst;	/* IPv6 destination address. */
+			} addr;
+			__be32 label;			/* IPv6 flow label. */
+			struct {
+				__be16 src;		/* TCP/UDP source port. */
+				__be16 dst;		/* TCP/UDP destination port. */
+			} tp;
+			struct {
+				struct in6_addr target;	/* ND target address. */
+				u8 sll[ETH_ALEN];	/* ND source link layer address. */
+				u8 tll[ETH_ALEN];	/* ND target link layer address. */
+			} nd;
+		} ipv6;
+	};
+};
+
+struct sw_flow {
+	struct rcu_head rcu;
+	struct hlist_node hash_node[2];
+	u32 hash;
+
+	struct sw_flow_key key;
+	struct sw_flow_actions __rcu *sf_acts;
+
+	spinlock_t lock;	/* Lock for values below. */
+	unsigned long used;	/* Last used time (in jiffies). */
+	u64 packet_count;	/* Number of packets matched. */
+	u64 byte_count;		/* Number of bytes matched. */
+	u8 tcp_flags;		/* Union of seen TCP flags. */
+};
+
+struct arp_eth_header {
+	__be16      ar_hrd;	/* format of hardware address   */
+	__be16      ar_pro;	/* format of protocol address   */
+	unsigned char   ar_hln;	/* length of hardware address   */
+	unsigned char   ar_pln;	/* length of protocol address   */
+	__be16      ar_op;	/* ARP opcode (command)     */
+
+	/* Ethernet+IPv4 specific members. */
+	unsigned char       ar_sha[ETH_ALEN];	/* sender hardware address  */
+	unsigned char       ar_sip[4];		/* sender IP address        */
+	unsigned char       ar_tha[ETH_ALEN];	/* target hardware address  */
+	unsigned char       ar_tip[4];		/* target IP address        */
+} __packed;
+
+int ovs_flow_init(void);
+void ovs_flow_exit(void);
+
+struct sw_flow *ovs_flow_alloc(void);
+void ovs_flow_deferred_free(struct sw_flow *);
+void ovs_flow_free(struct sw_flow *flow);
+
+struct sw_flow_actions *ovs_flow_actions_alloc(const struct nlattr *);
+void ovs_flow_deferred_free_acts(struct sw_flow_actions *);
+
+int ovs_flow_extract(struct sk_buff *, u16 in_port, struct sw_flow_key *,
+		     int *key_lenp);
+void ovs_flow_used(struct sw_flow *, struct sk_buff *);
+u64 ovs_flow_used_time(unsigned long flow_jiffies);
+
+/* Upper bound on the length of a nlattr-formatted flow key.  The longest
+ * nlattr-formatted flow key would be:
+ *
+ *                         struct  pad  nl hdr  total
+ *                         ------  ---  ------  -----
+ *  OVS_KEY_ATTR_PRIORITY      4    --     4      8
+ *  OVS_KEY_ATTR_IN_PORT       4    --     4      8
+ *  OVS_KEY_ATTR_ETHERNET     12    --     4     16
+ *  OVS_KEY_ATTR_8021Q         4    --     4      8
+ *  OVS_KEY_ATTR_ETHERTYPE     2     2     4      8
+ *  OVS_KEY_ATTR_IPV6         40    --     4     44
+ *  OVS_KEY_ATTR_ICMPV6        2     2     4      8
+ *  OVS_KEY_ATTR_ND           28    --     4     32
+ *  -------------------------------------------------
+ *  total                                       132
+ */
+#define FLOW_BUFSIZE 132
+
+int ovs_flow_to_nlattrs(const struct sw_flow_key *, struct sk_buff *);
+int ovs_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_lenp,
+		      const struct nlattr *);
+int ovs_flow_metadata_from_nlattrs(u32 *priority, u16 *in_port,
+			       const struct nlattr *);
+
+#define TBL_MIN_BUCKETS		1024
+
+struct flow_table {
+	struct flex_array *buckets;
+	unsigned int count, n_buckets;
+	struct rcu_head rcu;
+	int node_ver;
+	u32 hash_seed;
+	bool keep_flows;
+};
+
+static inline int ovs_flow_tbl_count(struct flow_table *table)
+{
+	return table->count;
+}
+
+static inline int ovs_flow_tbl_need_to_expand(struct flow_table *table)
+{
+	return (table->count > table->n_buckets);
+}
+
+struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *table,
+				    struct sw_flow_key *key, int len);
+void ovs_flow_tbl_destroy(struct flow_table *table);
+void ovs_flow_tbl_deferred_destroy(struct flow_table *table);
+struct flow_table *ovs_flow_tbl_alloc(int new_size);
+struct flow_table *ovs_flow_tbl_expand(struct flow_table *table);
+struct flow_table *ovs_flow_tbl_rehash(struct flow_table *table);
+void ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow);
+void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow);
+u32 ovs_flow_hash(const struct sw_flow_key *key, int key_len);
+
+struct sw_flow *ovs_flow_tbl_next(struct flow_table *table, u32 *bucket, u32 *idx);
+extern const int ovs_key_lens[OVS_KEY_ATTR_MAX + 1];
+
+#endif /* flow.h */