net/openvswitch/actions.c - LeafOS-Devices/android_kernel_realme_mt6785 - Gitiles

 /*
  * Copyright (c) 2007-2014 Nicira, Inc.
  *
  * 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
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/skbuff.h>
 #include <linux/in.h>
 #include <linux/ip.h>
 #include <linux/openvswitch.h>
 #include <linux/sctp.h>
 #include <linux/tcp.h>
 #include <linux/udp.h>
 #include <linux/in6.h>
 #include <linux/if_arp.h>
 #include <linux/if_vlan.h>

 #include <net/ip.h>
 #include <net/ipv6.h>
 #include <net/checksum.h>
 #include <net/dsfield.h>
 #include <net/mpls.h>
 #include <net/sctp/checksum.h>

 #include "datapath.h"
 #include "flow.h"
 #include "vport.h"

 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 			      struct sw_flow_key *key,
 			      const struct nlattr *attr, int len);

 struct deferred_action {
 	struct sk_buff *skb;
 	const struct nlattr *actions;

 	/* Store pkt_key clone when creating deferred action. */
 	struct sw_flow_key pkt_key;
 };

 #define DEFERRED_ACTION_FIFO_SIZE 10
 struct action_fifo {
 	int head;
 	int tail;
 	/* Deferred action fifo queue storage. */
 	struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
 };

 static struct action_fifo __percpu *action_fifos;
 static DEFINE_PER_CPU(int, exec_actions_level);

 static void action_fifo_init(struct action_fifo *fifo)
 {
 	fifo->head = 0;
 	fifo->tail = 0;
 }

 static bool action_fifo_is_empty(const struct action_fifo *fifo)
 {
 	return (fifo->head == fifo->tail);
 }

 static struct deferred_action *action_fifo_get(struct action_fifo *fifo)
 {
 	if (action_fifo_is_empty(fifo))
 		return NULL;

 	return &fifo->fifo[fifo->tail++];
 }

 static struct deferred_action *action_fifo_put(struct action_fifo *fifo)
 {
 	if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
 		return NULL;

 	return &fifo->fifo[fifo->head++];
 }

 /* Return true if fifo is not full */
 static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
 						    const struct sw_flow_key *key,
 						    const struct nlattr *attr)
 {
 	struct action_fifo *fifo;
 	struct deferred_action *da;

 	fifo = this_cpu_ptr(action_fifos);
 	da = action_fifo_put(fifo);
 	if (da) {
 		da->skb = skb;
 		da->actions = attr;
 		da->pkt_key = *key;
 	}

 	return da;
 }

 static void invalidate_flow_key(struct sw_flow_key *key)
 {
 	key->eth.type = htons(0);
 }

 static bool is_flow_key_valid(const struct sw_flow_key *key)
 {
 	return !!key->eth.type;
 }

 static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 		     const struct ovs_action_push_mpls *mpls)
 {
 	__be32 *new_mpls_lse;
 	struct ethhdr *hdr;

 	/* Networking stack do not allow simultaneous Tunnel and MPLS GSO. */
 	if (skb->encapsulation)
 		return -ENOTSUPP;

 	if (skb_cow_head(skb, MPLS_HLEN) < 0)
 		return -ENOMEM;

 	skb_push(skb, MPLS_HLEN);
 	memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
 		skb->mac_len);
 	skb_reset_mac_header(skb);

 	new_mpls_lse = (__be32 *)skb_mpls_header(skb);
 	*new_mpls_lse = mpls->mpls_lse;

 	if (skb->ip_summed == CHECKSUM_COMPLETE)
 		skb->csum = csum_add(skb->csum, csum_partial(new_mpls_lse,
 							     MPLS_HLEN, 0));

 	hdr = eth_hdr(skb);
 	hdr->h_proto = mpls->mpls_ethertype;

 	if (!skb->inner_protocol)
 		skb_set_inner_protocol(skb, skb->protocol);
 	skb->protocol = mpls->mpls_ethertype;

 	invalidate_flow_key(key);
 	return 0;
 }

 static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 		    const __be16 ethertype)
 {
 	struct ethhdr *hdr;
 	int err;

 	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
 	if (unlikely(err))
 		return err;

 	skb_postpull_rcsum(skb, skb_mpls_header(skb), MPLS_HLEN);

 	memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
 		skb->mac_len);

 	__skb_pull(skb, MPLS_HLEN);
 	skb_reset_mac_header(skb);

 	/* skb_mpls_header() is used to locate the ethertype
 	 * field correctly in the presence of VLAN tags.
 	 */
 	hdr = (struct ethhdr *)(skb_mpls_header(skb) - ETH_HLEN);
 	hdr->h_proto = ethertype;
 	if (eth_p_mpls(skb->protocol))
 		skb->protocol = ethertype;

 	invalidate_flow_key(key);
 	return 0;
 }

 static int set_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 		    const __be32 *mpls_lse)
 {
 	__be32 *stack;
 	int err;

 	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
 	if (unlikely(err))
 		return err;

 	stack = (__be32 *)skb_mpls_header(skb);
 	if (skb->ip_summed == CHECKSUM_COMPLETE) {
 		__be32 diff[] = { ~(*stack), *mpls_lse };
 		skb->csum = ~csum_partial((char *)diff, sizeof(diff),
 					  ~skb->csum);
 	}

 	*stack = *mpls_lse;
 	key->mpls.top_lse = *mpls_lse;
 	return 0;
 }

 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 {
 	int err;

 	err = skb_vlan_pop(skb);
 	if (skb_vlan_tag_present(skb))
 		invalidate_flow_key(key);
 	else
 		key->eth.tci = 0;
 	return err;
 }

 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
 		     const struct ovs_action_push_vlan *vlan)
 {
 	if (skb_vlan_tag_present(skb))
 		invalidate_flow_key(key);
 	else
 		key->eth.tci = vlan->vlan_tci;
 	return skb_vlan_push(skb, vlan->vlan_tpid,
 			     ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
 }

 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *key,
 			const struct ovs_key_ethernet *eth_key)
 {
 	int err;
 	err = skb_ensure_writable(skb, ETH_HLEN);
 	if (unlikely(err))
 		return err;

 	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);

 	ether_addr_copy(eth_hdr(skb)->h_source, eth_key->eth_src);
 	ether_addr_copy(eth_hdr(skb)->h_dest, eth_key->eth_dst);

 	ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);

 	ether_addr_copy(key->eth.src, eth_key->eth_src);
 	ether_addr_copy(key->eth.dst, eth_key->eth_dst);
 	return 0;
 }

 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
 			__be32 *addr, __be32 new_addr)
 {
 	int transport_len = skb->len - skb_transport_offset(skb);

 	if (nh->protocol == IPPROTO_TCP) {
 		if (likely(transport_len >= sizeof(struct tcphdr)))
 			inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
 						 *addr, new_addr, 1);
 	} else if (nh->protocol == IPPROTO_UDP) {
 		if (likely(transport_len >= sizeof(struct udphdr))) {
 			struct udphdr *uh = udp_hdr(skb);

 			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 				inet_proto_csum_replace4(&uh->check, skb,
 							 *addr, new_addr, 1);
 				if (!uh->check)
 					uh->check = CSUM_MANGLED_0;
 			}
 		}
 	}

 	csum_replace4(&nh->check, *addr, new_addr);
 	skb_clear_hash(skb);
 	*addr = new_addr;
 }

 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
 				 __be32 addr[4], const __be32 new_addr[4])
 {
 	int transport_len = skb->len - skb_transport_offset(skb);

 	if (l4_proto == NEXTHDR_TCP) {
 		if (likely(transport_len >= sizeof(struct tcphdr)))
 			inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
 						  addr, new_addr, 1);
 	} else if (l4_proto == NEXTHDR_UDP) {
 		if (likely(transport_len >= sizeof(struct udphdr))) {
 			struct udphdr *uh = udp_hdr(skb);

 			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 				inet_proto_csum_replace16(&uh->check, skb,
 							  addr, new_addr, 1);
 				if (!uh->check)
 					uh->check = CSUM_MANGLED_0;
 			}
 		}
 	} else if (l4_proto == NEXTHDR_ICMP) {
 		if (likely(transport_len >= sizeof(struct icmp6hdr)))
 			inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
 						  skb, addr, new_addr, 1);
 	}
 }

 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
 			  __be32 addr[4], const __be32 new_addr[4],
 			  bool recalculate_csum)
 {
 	if (recalculate_csum)
 		update_ipv6_checksum(skb, l4_proto, addr, new_addr);

 	skb_clear_hash(skb);
 	memcpy(addr, new_addr, sizeof(__be32[4]));
 }

 static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
 {
 	nh->priority = tc >> 4;
 	nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4);
 }

 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
 {
 	nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16;
 	nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
 	nh->flow_lbl[2] = fl & 0x000000FF;
 }

 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
 {
 	csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
 	nh->ttl = new_ttl;
 }

 static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *key,
 		    const struct ovs_key_ipv4 *ipv4_key)
 {
 	struct iphdr *nh;
 	int err;

 	err = skb_ensure_writable(skb, skb_network_offset(skb) +
 				  sizeof(struct iphdr));
 	if (unlikely(err))
 		return err;

 	nh = ip_hdr(skb);

 	if (ipv4_key->ipv4_src != nh->saddr) {
 		set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
 		key->ipv4.addr.src = ipv4_key->ipv4_src;
 	}

 	if (ipv4_key->ipv4_dst != nh->daddr) {
 		set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
 		key->ipv4.addr.dst = ipv4_key->ipv4_dst;
 	}

 	if (ipv4_key->ipv4_tos != nh->tos) {
 		ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
 		key->ip.tos = nh->tos;
 	}

 	if (ipv4_key->ipv4_ttl != nh->ttl) {
 		set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
 		key->ip.ttl = ipv4_key->ipv4_ttl;
 	}

 	return 0;
 }

 static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *key,
 		    const struct ovs_key_ipv6 *ipv6_key)
 {
 	struct ipv6hdr *nh;
 	int err;
 	__be32 *saddr;
 	__be32 *daddr;

 	err = skb_ensure_writable(skb, skb_network_offset(skb) +
 				  sizeof(struct ipv6hdr));
 	if (unlikely(err))
 		return err;

 	nh = ipv6_hdr(skb);
 	saddr = (__be32 *)&nh->saddr;
 	daddr = (__be32 *)&nh->daddr;

 	if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src))) {
 		set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
 			      ipv6_key->ipv6_src, true);
 		memcpy(&key->ipv6.addr.src, ipv6_key->ipv6_src,
 		       sizeof(ipv6_key->ipv6_src));
 	}

 	if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
 		unsigned int offset = 0;
 		int flags = IP6_FH_F_SKIP_RH;
 		bool recalc_csum = true;

 		if (ipv6_ext_hdr(nh->nexthdr))
 			recalc_csum = ipv6_find_hdr(skb, &offset,
 						    NEXTHDR_ROUTING, NULL,
 						    &flags) != NEXTHDR_ROUTING;

 		set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
 			      ipv6_key->ipv6_dst, recalc_csum);
 		memcpy(&key->ipv6.addr.dst, ipv6_key->ipv6_dst,
 		       sizeof(ipv6_key->ipv6_dst));
 	}

 	set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
 	key->ip.tos = ipv6_get_dsfield(nh);

 	set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
 	key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);

 	nh->hop_limit = ipv6_key->ipv6_hlimit;
 	key->ip.ttl = ipv6_key->ipv6_hlimit;
 	return 0;
 }

 /* Must follow skb_ensure_writable() since that can move the skb data. */
 static void set_tp_port(struct sk_buff *skb, __be16 *port,
 			 __be16 new_port, __sum16 *check)
 {
 	inet_proto_csum_replace2(check, skb, *port, new_port, 0);
 	*port = new_port;
 	skb_clear_hash(skb);
 }

 static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
 {
 	struct udphdr *uh = udp_hdr(skb);

 	if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
 		set_tp_port(skb, port, new_port, &uh->check);

 		if (!uh->check)
 			uh->check = CSUM_MANGLED_0;
 	} else {
 		*port = new_port;
 		skb_clear_hash(skb);
 	}
 }

 static int set_udp(struct sk_buff *skb, struct sw_flow_key *key,
 		   const struct ovs_key_udp *udp_port_key)
 {
 	struct udphdr *uh;
 	int err;

 	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 				  sizeof(struct udphdr));
 	if (unlikely(err))
 		return err;

 	uh = udp_hdr(skb);
 	if (udp_port_key->udp_src != uh->source) {
 		set_udp_port(skb, &uh->source, udp_port_key->udp_src);
 		key->tp.src = udp_port_key->udp_src;
 	}

 	if (udp_port_key->udp_dst != uh->dest) {
 		set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
 		key->tp.dst = udp_port_key->udp_dst;
 	}

 	return 0;
 }

 static int set_tcp(struct sk_buff *skb, struct sw_flow_key *key,
 		   const struct ovs_key_tcp *tcp_port_key)
 {
 	struct tcphdr *th;
 	int err;

 	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 				  sizeof(struct tcphdr));
 	if (unlikely(err))
 		return err;

 	th = tcp_hdr(skb);
 	if (tcp_port_key->tcp_src != th->source) {
 		set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check);
 		key->tp.src = tcp_port_key->tcp_src;
 	}

 	if (tcp_port_key->tcp_dst != th->dest) {
 		set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check);
 		key->tp.dst = tcp_port_key->tcp_dst;
 	}

 	return 0;
 }

 static int set_sctp(struct sk_buff *skb, struct sw_flow_key *key,
 		    const struct ovs_key_sctp *sctp_port_key)
 {
 	struct sctphdr *sh;
 	int err;
 	unsigned int sctphoff = skb_transport_offset(skb);

 	err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
 	if (unlikely(err))
 		return err;

 	sh = sctp_hdr(skb);
 	if (sctp_port_key->sctp_src != sh->source ||
 	    sctp_port_key->sctp_dst != sh->dest) {
 		__le32 old_correct_csum, new_csum, old_csum;

 		old_csum = sh->checksum;
 		old_correct_csum = sctp_compute_cksum(skb, sctphoff);

 		sh->source = sctp_port_key->sctp_src;
 		sh->dest = sctp_port_key->sctp_dst;

 		new_csum = sctp_compute_cksum(skb, sctphoff);

 		/* Carry any checksum errors through. */
 		sh->checksum = old_csum ^ old_correct_csum ^ new_csum;

 		skb_clear_hash(skb);
 		key->tp.src = sctp_port_key->sctp_src;
 		key->tp.dst = sctp_port_key->sctp_dst;
 	}

 	return 0;
 }

 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
 {
 	struct vport *vport = ovs_vport_rcu(dp, out_port);

 	if (likely(vport))
 		ovs_vport_send(vport, skb);
 	else
 		kfree_skb(skb);
 }

 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
 			    struct sw_flow_key *key, const struct nlattr *attr)
 {
 	struct ovs_tunnel_info info;
 	struct dp_upcall_info upcall;
 	const struct nlattr *a;
 	int rem;

 	upcall.cmd = OVS_PACKET_CMD_ACTION;
 	upcall.userdata = NULL;
 	upcall.portid = 0;
 	upcall.egress_tun_info = NULL;

 	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 		 a = nla_next(a, &rem)) {
 		switch (nla_type(a)) {
 		case OVS_USERSPACE_ATTR_USERDATA:
 			upcall.userdata = a;
 			break;

 		case OVS_USERSPACE_ATTR_PID:
 			upcall.portid = nla_get_u32(a);
 			break;

 		case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
 			/* Get out tunnel info. */
 			struct vport *vport;

 			vport = ovs_vport_rcu(dp, nla_get_u32(a));
 			if (vport) {
 				int err;

 				err = ovs_vport_get_egress_tun_info(vport, skb,
 								    &info);
 				if (!err)
 					upcall.egress_tun_info = &info;
 			}
 			break;
 		}

 		} /* End of switch. */
 	}

 	return ovs_dp_upcall(dp, skb, key, &upcall);
 }

 static int sample(struct datapath *dp, struct sk_buff *skb,
 		  struct sw_flow_key *key, const struct nlattr *attr)
 {
 	const struct nlattr *acts_list = NULL;
 	const struct nlattr *a;
 	int rem;

 	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 		 a = nla_next(a, &rem)) {
 		switch (nla_type(a)) {
 		case OVS_SAMPLE_ATTR_PROBABILITY:
 			if (prandom_u32() >= nla_get_u32(a))
 				return 0;
 			break;

 		case OVS_SAMPLE_ATTR_ACTIONS:
 			acts_list = a;
 			break;
 		}
 	}

 	rem = nla_len(acts_list);
 	a = nla_data(acts_list);

 	/* Actions list is empty, do nothing */
 	if (unlikely(!rem))
 		return 0;

 	/* The only known usage of sample action is having a single user-space
 	 * action. Treat this usage as a special case.
 	 * The output_userspace() should clone the skb to be sent to the
 	 * user space. This skb will be consumed by its caller.
 	 */
 	if (likely(nla_type(a) == OVS_ACTION_ATTR_USERSPACE &&
 		   nla_is_last(a, rem)))
 		return output_userspace(dp, skb, key, a);

 	skb = skb_clone(skb, GFP_ATOMIC);
 	if (!skb)
 		/* Skip the sample action when out of memory. */
 		return 0;

 	if (!add_deferred_actions(skb, key, a)) {
 		if (net_ratelimit())
 			pr_warn("%s: deferred actions limit reached, dropping sample action\n",
 				ovs_dp_name(dp));

 		kfree_skb(skb);
 	}
 	return 0;
 }

 static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
 			 const struct nlattr *attr)
 {
 	struct ovs_action_hash *hash_act = nla_data(attr);
 	u32 hash = 0;

 	/* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
 	hash = skb_get_hash(skb);
 	hash = jhash_1word(hash, hash_act->hash_basis);
 	if (!hash)
 		hash = 0x1;

 	key->ovs_flow_hash = hash;
 }

 static int execute_set_action(struct sk_buff *skb, struct sw_flow_key *key,
 			      const struct nlattr *nested_attr)
 {
 	int err = 0;

 	switch (nla_type(nested_attr)) {
 	case OVS_KEY_ATTR_PRIORITY:
 		skb->priority = nla_get_u32(nested_attr);
 		key->phy.priority = skb->priority;
 		break;

 	case OVS_KEY_ATTR_SKB_MARK:
 		skb->mark = nla_get_u32(nested_attr);
 		key->phy.skb_mark = skb->mark;
 		break;

 	case OVS_KEY_ATTR_TUNNEL_INFO:
 		OVS_CB(skb)->egress_tun_info = nla_data(nested_attr);
 		break;

 	case OVS_KEY_ATTR_ETHERNET:
 		err = set_eth_addr(skb, key, nla_data(nested_attr));
 		break;

 	case OVS_KEY_ATTR_IPV4:
 		err = set_ipv4(skb, key, nla_data(nested_attr));
 		break;

 	case OVS_KEY_ATTR_IPV6:
 		err = set_ipv6(skb, key, nla_data(nested_attr));
 		break;

 	case OVS_KEY_ATTR_TCP:
 		err = set_tcp(skb, key, nla_data(nested_attr));
 		break;

 	case OVS_KEY_ATTR_UDP:
 		err = set_udp(skb, key, nla_data(nested_attr));
 		break;

 	case OVS_KEY_ATTR_SCTP:
 		err = set_sctp(skb, key, nla_data(nested_attr));
 		break;

 	case OVS_KEY_ATTR_MPLS:
 		err = set_mpls(skb, key, nla_data(nested_attr));
 		break;
 	}

 	return err;
 }

 static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
 			  struct sw_flow_key *key,
 			  const struct nlattr *a, int rem)
 {
 	struct deferred_action *da;

 	if (!is_flow_key_valid(key)) {
 		int err;

 		err = ovs_flow_key_update(skb, key);
 		if (err)
 			return err;
 	}
 	BUG_ON(!is_flow_key_valid(key));

 	if (!nla_is_last(a, rem)) {
 		/* Recirc action is the not the last action
 		 * of the action list, need to clone the skb.
 		 */
 		skb = skb_clone(skb, GFP_ATOMIC);

 		/* Skip the recirc action when out of memory, but
 		 * continue on with the rest of the action list.
 		 */
 		if (!skb)
 			return 0;
 	}

 	da = add_deferred_actions(skb, key, NULL);
 	if (da) {
 		da->pkt_key.recirc_id = nla_get_u32(a);
 	} else {
 		kfree_skb(skb);

 		if (net_ratelimit())
 			pr_warn("%s: deferred action limit reached, drop recirc action\n",
 				ovs_dp_name(dp));
 	}

 	return 0;
 }

 /* Execute a list of actions against 'skb'. */
 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 			      struct sw_flow_key *key,
 			      const struct nlattr *attr, int len)
 {
 	/* Every output action needs a separate clone of 'skb', but the common
 	 * case is just a single output action, so that doing a clone and
 	 * then freeing the original skbuff is wasteful.  So the following code
 	 * is slightly obscure just to avoid that.
 	 */
 	int prev_port = -1;
 	const struct nlattr *a;
 	int rem;

 	for (a = attr, rem = len; rem > 0;
 	     a = nla_next(a, &rem)) {
 		int err = 0;

 		if (unlikely(prev_port != -1)) {
 			struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC);

 			if (out_skb)
 				do_output(dp, out_skb, prev_port);

 			prev_port = -1;
 		}

 		switch (nla_type(a)) {
 		case OVS_ACTION_ATTR_OUTPUT:
 			prev_port = nla_get_u32(a);
 			break;

 		case OVS_ACTION_ATTR_USERSPACE:
 			output_userspace(dp, skb, key, a);
 			break;

 		case OVS_ACTION_ATTR_HASH:
 			execute_hash(skb, key, a);
 			break;

 		case OVS_ACTION_ATTR_PUSH_MPLS:
 			err = push_mpls(skb, key, nla_data(a));
 			break;

 		case OVS_ACTION_ATTR_POP_MPLS:
 			err = pop_mpls(skb, key, nla_get_be16(a));
 			break;

 		case OVS_ACTION_ATTR_PUSH_VLAN:
 			err = push_vlan(skb, key, nla_data(a));
 			break;

 		case OVS_ACTION_ATTR_POP_VLAN:
 			err = pop_vlan(skb, key);
 			break;

 		case OVS_ACTION_ATTR_RECIRC:
 			err = execute_recirc(dp, skb, key, a, rem);
 			if (nla_is_last(a, rem)) {
 				/* If this is the last action, the skb has
 				 * been consumed or freed.
 				 * Return immediately.
 				 */
 				return err;
 			}
 			break;

 		case OVS_ACTION_ATTR_SET:
 			err = execute_set_action(skb, key, nla_data(a));
 			break;

 		case OVS_ACTION_ATTR_SAMPLE:
 			err = sample(dp, skb, key, a);
 			break;
 		}

 		if (unlikely(err)) {
 			kfree_skb(skb);
 			return err;
 		}
 	}

 	if (prev_port != -1)
 		do_output(dp, skb, prev_port);
 	else
 		consume_skb(skb);

 	return 0;
 }

 static void process_deferred_actions(struct datapath *dp)
 {
 	struct action_fifo *fifo = this_cpu_ptr(action_fifos);

 	/* Do not touch the FIFO in case there is no deferred actions. */
 	if (action_fifo_is_empty(fifo))
 		return;

 	/* Finishing executing all deferred actions. */
 	do {
 		struct deferred_action *da = action_fifo_get(fifo);
 		struct sk_buff *skb = da->skb;
 		struct sw_flow_key *key = &da->pkt_key;
 		const struct nlattr *actions = da->actions;

 		if (actions)
 			do_execute_actions(dp, skb, key, actions,
 					   nla_len(actions));
 		else
 			ovs_dp_process_packet(skb, key);
 	} while (!action_fifo_is_empty(fifo));

 	/* Reset FIFO for the next packet.  */
 	action_fifo_init(fifo);
 }

 /* Execute a list of actions against 'skb'. */
 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 			const struct sw_flow_actions *acts,
 			struct sw_flow_key *key)
 {
 	int level = this_cpu_read(exec_actions_level);
 	int err;

 	this_cpu_inc(exec_actions_level);
 	OVS_CB(skb)->egress_tun_info = NULL;
 	err = do_execute_actions(dp, skb, key,
 				 acts->actions, acts->actions_len);

 	if (!level)
 		process_deferred_actions(dp);

 	this_cpu_dec(exec_actions_level);
 	return err;
 }

 int action_fifos_init(void)
 {
 	action_fifos = alloc_percpu(struct action_fifo);
 	if (!action_fifos)
 		return -ENOMEM;

 	return 0;
 }

 void action_fifos_exit(void)
 {
 	free_percpu(action_fifos);
 }
	/*
	* Copyright (c) 2007-2014 Nicira, Inc.
	*
	* 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
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/skbuff.h>
	#include <linux/in.h>
	#include <linux/ip.h>
	#include <linux/openvswitch.h>
	#include <linux/sctp.h>
	#include <linux/tcp.h>
	#include <linux/udp.h>
	#include <linux/in6.h>
	#include <linux/if_arp.h>
	#include <linux/if_vlan.h>

	#include <net/ip.h>
	#include <net/ipv6.h>
	#include <net/checksum.h>
	#include <net/dsfield.h>
	#include <net/mpls.h>
	#include <net/sctp/checksum.h>

	#include "datapath.h"
	#include "flow.h"
	#include "vport.h"

	static int do_execute_actions(struct datapath dp, struct sk_buff skb,
	struct sw_flow_key *key,
	const struct nlattr *attr, int len);

	struct deferred_action {
	struct sk_buff *skb;
	const struct nlattr *actions;

	/* Store pkt_key clone when creating deferred action. */
	struct sw_flow_key pkt_key;
	};

	#define DEFERRED_ACTION_FIFO_SIZE 10
	struct action_fifo {
	int head;
	int tail;
	/* Deferred action fifo queue storage. */
	struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
	};

	static struct action_fifo __percpu *action_fifos;
	static DEFINE_PER_CPU(int, exec_actions_level);

	static void action_fifo_init(struct action_fifo *fifo)
	{
	fifo->head = 0;
	fifo->tail = 0;
	}

	static bool action_fifo_is_empty(const struct action_fifo *fifo)
	{
	return (fifo->head == fifo->tail);
	}

	static struct deferred_action action_fifo_get(struct action_fifo fifo)
	{
	if (action_fifo_is_empty(fifo))
	return NULL;

	return &fifo->fifo[fifo->tail++];
	}

	static struct deferred_action action_fifo_put(struct action_fifo fifo)
	{
	if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
	return NULL;

	return &fifo->fifo[fifo->head++];
	}

	/* Return true if fifo is not full */
	static struct deferred_action add_deferred_actions(struct sk_buff skb,
	const struct sw_flow_key *key,
	const struct nlattr *attr)
	{
	struct action_fifo *fifo;
	struct deferred_action *da;

	fifo = this_cpu_ptr(action_fifos);
	da = action_fifo_put(fifo);
	if (da) {
	da->skb = skb;
	da->actions = attr;
	da->pkt_key = *key;
	}

	return da;
	}

	static void invalidate_flow_key(struct sw_flow_key *key)
	{
	key->eth.type = htons(0);
	}

	static bool is_flow_key_valid(const struct sw_flow_key *key)
	{
	return !!key->eth.type;
	}

	static int push_mpls(struct sk_buff skb, struct sw_flow_key key,
	const struct ovs_action_push_mpls *mpls)
	{
	__be32 *new_mpls_lse;
	struct ethhdr *hdr;

	/* Networking stack do not allow simultaneous Tunnel and MPLS GSO. */
	if (skb->encapsulation)
	return -ENOTSUPP;

	if (skb_cow_head(skb, MPLS_HLEN) < 0)
	return -ENOMEM;

	skb_push(skb, MPLS_HLEN);
	memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
	skb->mac_len);
	skb_reset_mac_header(skb);

	new_mpls_lse = (__be32 *)skb_mpls_header(skb);
	*new_mpls_lse = mpls->mpls_lse;

	if (skb->ip_summed == CHECKSUM_COMPLETE)
	skb->csum = csum_add(skb->csum, csum_partial(new_mpls_lse,
	MPLS_HLEN, 0));

	hdr = eth_hdr(skb);
	hdr->h_proto = mpls->mpls_ethertype;

	if (!skb->inner_protocol)
	skb_set_inner_protocol(skb, skb->protocol);
	skb->protocol = mpls->mpls_ethertype;

	invalidate_flow_key(key);
	return 0;
	}

	static int pop_mpls(struct sk_buff skb, struct sw_flow_key key,
	const __be16 ethertype)
	{
	struct ethhdr *hdr;
	int err;

	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
	if (unlikely(err))
	return err;

	skb_postpull_rcsum(skb, skb_mpls_header(skb), MPLS_HLEN);

	memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
	skb->mac_len);

	__skb_pull(skb, MPLS_HLEN);
	skb_reset_mac_header(skb);

	/* skb_mpls_header() is used to locate the ethertype
	* field correctly in the presence of VLAN tags.
	*/
	hdr = (struct ethhdr *)(skb_mpls_header(skb) - ETH_HLEN);
	hdr->h_proto = ethertype;
	if (eth_p_mpls(skb->protocol))
	skb->protocol = ethertype;

	invalidate_flow_key(key);
	return 0;
	}

	static int set_mpls(struct sk_buff skb, struct sw_flow_key key,
	const __be32 *mpls_lse)
	{
	__be32 *stack;
	int err;

	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
	if (unlikely(err))
	return err;

	stack = (__be32 *)skb_mpls_header(skb);
	if (skb->ip_summed == CHECKSUM_COMPLETE) {
	__be32 diff[] = { ~(stack), mpls_lse };
	skb->csum = ~csum_partial((char *)diff, sizeof(diff),
	~skb->csum);
	}

	stack = mpls_lse;
	key->mpls.top_lse = *mpls_lse;
	return 0;
	}

	static int pop_vlan(struct sk_buff skb, struct sw_flow_key key)
	{
	int err;

	err = skb_vlan_pop(skb);
	if (skb_vlan_tag_present(skb))
	invalidate_flow_key(key);
	else
	key->eth.tci = 0;
	return err;
	}

	static int push_vlan(struct sk_buff skb, struct sw_flow_key key,
	const struct ovs_action_push_vlan *vlan)
	{
	if (skb_vlan_tag_present(skb))
	invalidate_flow_key(key);
	else
	key->eth.tci = vlan->vlan_tci;
	return skb_vlan_push(skb, vlan->vlan_tpid,
	ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
	}

	static int set_eth_addr(struct sk_buff skb, struct sw_flow_key key,
	const struct ovs_key_ethernet *eth_key)
	{
	int err;
	err = skb_ensure_writable(skb, ETH_HLEN);
	if (unlikely(err))
	return err;

	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);

	ether_addr_copy(eth_hdr(skb)->h_source, eth_key->eth_src);
	ether_addr_copy(eth_hdr(skb)->h_dest, eth_key->eth_dst);

	ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);

	ether_addr_copy(key->eth.src, eth_key->eth_src);
	ether_addr_copy(key->eth.dst, eth_key->eth_dst);
	return 0;
	}

	static void set_ip_addr(struct sk_buff skb, struct iphdr nh,
	__be32 *addr, __be32 new_addr)
	{
	int transport_len = skb->len - skb_transport_offset(skb);

	if (nh->protocol == IPPROTO_TCP) {
	if (likely(transport_len >= sizeof(struct tcphdr)))
	inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
	*addr, new_addr, 1);
	} else if (nh->protocol == IPPROTO_UDP) {
	if (likely(transport_len >= sizeof(struct udphdr))) {
	struct udphdr *uh = udp_hdr(skb);

	if (uh->check \|\| skb->ip_summed == CHECKSUM_PARTIAL) {
	inet_proto_csum_replace4(&uh->check, skb,
	*addr, new_addr, 1);
	if (!uh->check)
	uh->check = CSUM_MANGLED_0;
	}
	}
	}

	csum_replace4(&nh->check, *addr, new_addr);
	skb_clear_hash(skb);
	*addr = new_addr;
	}

	static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
	__be32 addr[4], const __be32 new_addr[4])
	{
	int transport_len = skb->len - skb_transport_offset(skb);

	if (l4_proto == NEXTHDR_TCP) {
	if (likely(transport_len >= sizeof(struct tcphdr)))
	inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
	addr, new_addr, 1);
	} else if (l4_proto == NEXTHDR_UDP) {
	if (likely(transport_len >= sizeof(struct udphdr))) {
	struct udphdr *uh = udp_hdr(skb);

	if (uh->check \|\| skb->ip_summed == CHECKSUM_PARTIAL) {
	inet_proto_csum_replace16(&uh->check, skb,
	addr, new_addr, 1);
	if (!uh->check)
	uh->check = CSUM_MANGLED_0;
	}
	}
	} else if (l4_proto == NEXTHDR_ICMP) {
	if (likely(transport_len >= sizeof(struct icmp6hdr)))
	inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
	skb, addr, new_addr, 1);
	}
	}

	static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
	__be32 addr[4], const __be32 new_addr[4],
	bool recalculate_csum)
	{
	if (recalculate_csum)
	update_ipv6_checksum(skb, l4_proto, addr, new_addr);

	skb_clear_hash(skb);
	memcpy(addr, new_addr, sizeof(__be32[4]));
	}

	static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
	{
	nh->priority = tc >> 4;
	nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) \| ((tc & 0x0F) << 4);
	}

	static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
	{
	nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) \| (fl & 0x000F0000) >> 16;
	nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
	nh->flow_lbl[2] = fl & 0x000000FF;
	}

	static void set_ip_ttl(struct sk_buff skb, struct iphdr nh, u8 new_ttl)
	{
	csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
	nh->ttl = new_ttl;
	}

	static int set_ipv4(struct sk_buff skb, struct sw_flow_key key,
	const struct ovs_key_ipv4 *ipv4_key)
	{
	struct iphdr *nh;
	int err;

	err = skb_ensure_writable(skb, skb_network_offset(skb) +
	sizeof(struct iphdr));
	if (unlikely(err))
	return err;

	nh = ip_hdr(skb);

	if (ipv4_key->ipv4_src != nh->saddr) {
	set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
	key->ipv4.addr.src = ipv4_key->ipv4_src;
	}

	if (ipv4_key->ipv4_dst != nh->daddr) {
	set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
	key->ipv4.addr.dst = ipv4_key->ipv4_dst;
	}

	if (ipv4_key->ipv4_tos != nh->tos) {
	ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
	key->ip.tos = nh->tos;
	}

	if (ipv4_key->ipv4_ttl != nh->ttl) {
	set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
	key->ip.ttl = ipv4_key->ipv4_ttl;
	}

	return 0;
	}

	static int set_ipv6(struct sk_buff skb, struct sw_flow_key key,
	const struct ovs_key_ipv6 *ipv6_key)
	{
	struct ipv6hdr *nh;
	int err;
	__be32 *saddr;
	__be32 *daddr;

	err = skb_ensure_writable(skb, skb_network_offset(skb) +
	sizeof(struct ipv6hdr));
	if (unlikely(err))
	return err;

	nh = ipv6_hdr(skb);
	saddr = (__be32 *)&nh->saddr;
	daddr = (__be32 *)&nh->daddr;

	if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src))) {
	set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
	ipv6_key->ipv6_src, true);
	memcpy(&key->ipv6.addr.src, ipv6_key->ipv6_src,
	sizeof(ipv6_key->ipv6_src));
	}

	if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
	unsigned int offset = 0;
	int flags = IP6_FH_F_SKIP_RH;
	bool recalc_csum = true;

	if (ipv6_ext_hdr(nh->nexthdr))
	recalc_csum = ipv6_find_hdr(skb, &offset,
	NEXTHDR_ROUTING, NULL,
	&flags) != NEXTHDR_ROUTING;

	set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
	ipv6_key->ipv6_dst, recalc_csum);
	memcpy(&key->ipv6.addr.dst, ipv6_key->ipv6_dst,
	sizeof(ipv6_key->ipv6_dst));
	}

	set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
	key->ip.tos = ipv6_get_dsfield(nh);

	set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
	key->ipv6.label = (__be32 )nh & htonl(IPV6_FLOWINFO_FLOWLABEL);

	nh->hop_limit = ipv6_key->ipv6_hlimit;
	key->ip.ttl = ipv6_key->ipv6_hlimit;
	return 0;
	}

	/* Must follow skb_ensure_writable() since that can move the skb data. */
	static void set_tp_port(struct sk_buff skb, __be16 port,
	__be16 new_port, __sum16 *check)
	{
	inet_proto_csum_replace2(check, skb, *port, new_port, 0);
	*port = new_port;
	skb_clear_hash(skb);
	}

	static void set_udp_port(struct sk_buff skb, __be16 port, __be16 new_port)
	{
	struct udphdr *uh = udp_hdr(skb);

	if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
	set_tp_port(skb, port, new_port, &uh->check);

	if (!uh->check)
	uh->check = CSUM_MANGLED_0;
	} else {
	*port = new_port;
	skb_clear_hash(skb);
	}
	}

	static int set_udp(struct sk_buff skb, struct sw_flow_key key,
	const struct ovs_key_udp *udp_port_key)
	{
	struct udphdr *uh;
	int err;

	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
	sizeof(struct udphdr));
	if (unlikely(err))
	return err;

	uh = udp_hdr(skb);
	if (udp_port_key->udp_src != uh->source) {
	set_udp_port(skb, &uh->source, udp_port_key->udp_src);
	key->tp.src = udp_port_key->udp_src;
	}

	if (udp_port_key->udp_dst != uh->dest) {
	set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
	key->tp.dst = udp_port_key->udp_dst;
	}

	return 0;
	}

	static int set_tcp(struct sk_buff skb, struct sw_flow_key key,
	const struct ovs_key_tcp *tcp_port_key)
	{
	struct tcphdr *th;
	int err;

	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
	sizeof(struct tcphdr));
	if (unlikely(err))
	return err;

	th = tcp_hdr(skb);
	if (tcp_port_key->tcp_src != th->source) {
	set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check);
	key->tp.src = tcp_port_key->tcp_src;
	}

	if (tcp_port_key->tcp_dst != th->dest) {
	set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check);
	key->tp.dst = tcp_port_key->tcp_dst;
	}

	return 0;
	}

	static int set_sctp(struct sk_buff skb, struct sw_flow_key key,
	const struct ovs_key_sctp *sctp_port_key)
	{
	struct sctphdr *sh;
	int err;
	unsigned int sctphoff = skb_transport_offset(skb);

	err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
	if (unlikely(err))
	return err;

	sh = sctp_hdr(skb);
	if (sctp_port_key->sctp_src != sh->source \|\|
	sctp_port_key->sctp_dst != sh->dest) {
	__le32 old_correct_csum, new_csum, old_csum;

	old_csum = sh->checksum;
	old_correct_csum = sctp_compute_cksum(skb, sctphoff);

	sh->source = sctp_port_key->sctp_src;
	sh->dest = sctp_port_key->sctp_dst;

	new_csum = sctp_compute_cksum(skb, sctphoff);

	/* Carry any checksum errors through. */
	sh->checksum = old_csum ^ old_correct_csum ^ new_csum;

	skb_clear_hash(skb);
	key->tp.src = sctp_port_key->sctp_src;
	key->tp.dst = sctp_port_key->sctp_dst;
	}

	return 0;
	}

	static void do_output(struct datapath dp, struct sk_buff skb, int out_port)
	{
	struct vport *vport = ovs_vport_rcu(dp, out_port);

	if (likely(vport))
	ovs_vport_send(vport, skb);
	else
	kfree_skb(skb);
	}

	static int output_userspace(struct datapath dp, struct sk_buff skb,
	struct sw_flow_key key, const struct nlattr attr)
	{
	struct ovs_tunnel_info info;
	struct dp_upcall_info upcall;
	const struct nlattr *a;
	int rem;

	upcall.cmd = OVS_PACKET_CMD_ACTION;
	upcall.userdata = NULL;
	upcall.portid = 0;
	upcall.egress_tun_info = NULL;

	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
	a = nla_next(a, &rem)) {
	switch (nla_type(a)) {
	case OVS_USERSPACE_ATTR_USERDATA:
	upcall.userdata = a;
	break;

	case OVS_USERSPACE_ATTR_PID:
	upcall.portid = nla_get_u32(a);
	break;

	case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
	/* Get out tunnel info. */
	struct vport *vport;

	vport = ovs_vport_rcu(dp, nla_get_u32(a));
	if (vport) {
	int err;

	err = ovs_vport_get_egress_tun_info(vport, skb,
	&info);
	if (!err)
	upcall.egress_tun_info = &info;
	}
	break;
	}

	} /* End of switch. */
	}

	return ovs_dp_upcall(dp, skb, key, &upcall);
	}

	static int sample(struct datapath dp, struct sk_buff skb,
	struct sw_flow_key key, const struct nlattr attr)
	{
	const struct nlattr *acts_list = NULL;
	const struct nlattr *a;
	int rem;

	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
	a = nla_next(a, &rem)) {
	switch (nla_type(a)) {
	case OVS_SAMPLE_ATTR_PROBABILITY:
	if (prandom_u32() >= nla_get_u32(a))
	return 0;
	break;

	case OVS_SAMPLE_ATTR_ACTIONS:
	acts_list = a;
	break;
	}
	}

	rem = nla_len(acts_list);
	a = nla_data(acts_list);

	/* Actions list is empty, do nothing */
	if (unlikely(!rem))
	return 0;

	/* The only known usage of sample action is having a single user-space
	* action. Treat this usage as a special case.
	* The output_userspace() should clone the skb to be sent to the
	* user space. This skb will be consumed by its caller.
	*/
	if (likely(nla_type(a) == OVS_ACTION_ATTR_USERSPACE &&
	nla_is_last(a, rem)))
	return output_userspace(dp, skb, key, a);

	skb = skb_clone(skb, GFP_ATOMIC);
	if (!skb)
	/* Skip the sample action when out of memory. */
	return 0;

	if (!add_deferred_actions(skb, key, a)) {
	if (net_ratelimit())
	pr_warn("%s: deferred actions limit reached, dropping sample action\n",
	ovs_dp_name(dp));

	kfree_skb(skb);
	}
	return 0;
	}

	static void execute_hash(struct sk_buff skb, struct sw_flow_key key,
	const struct nlattr *attr)
	{
	struct ovs_action_hash *hash_act = nla_data(attr);
	u32 hash = 0;

	/* OVS_HASH_ALG_L4 is the only possible hash algorithm. */
	hash = skb_get_hash(skb);
	hash = jhash_1word(hash, hash_act->hash_basis);
	if (!hash)
	hash = 0x1;

	key->ovs_flow_hash = hash;
	}

	static int execute_set_action(struct sk_buff skb, struct sw_flow_key key,
	const struct nlattr *nested_attr)
	{
	int err = 0;

	switch (nla_type(nested_attr)) {
	case OVS_KEY_ATTR_PRIORITY:
	skb->priority = nla_get_u32(nested_attr);
	key->phy.priority = skb->priority;
	break;

	case OVS_KEY_ATTR_SKB_MARK:
	skb->mark = nla_get_u32(nested_attr);
	key->phy.skb_mark = skb->mark;
	break;

	case OVS_KEY_ATTR_TUNNEL_INFO:
	OVS_CB(skb)->egress_tun_info = nla_data(nested_attr);
	break;

	case OVS_KEY_ATTR_ETHERNET:
	err = set_eth_addr(skb, key, nla_data(nested_attr));
	break;

	case OVS_KEY_ATTR_IPV4:
	err = set_ipv4(skb, key, nla_data(nested_attr));
	break;

	case OVS_KEY_ATTR_IPV6:
	err = set_ipv6(skb, key, nla_data(nested_attr));
	break;

	case OVS_KEY_ATTR_TCP:
	err = set_tcp(skb, key, nla_data(nested_attr));
	break;

	case OVS_KEY_ATTR_UDP:
	err = set_udp(skb, key, nla_data(nested_attr));
	break;

	case OVS_KEY_ATTR_SCTP:
	err = set_sctp(skb, key, nla_data(nested_attr));
	break;

	case OVS_KEY_ATTR_MPLS:
	err = set_mpls(skb, key, nla_data(nested_attr));
	break;
	}

	return err;
	}

	static int execute_recirc(struct datapath dp, struct sk_buff skb,
	struct sw_flow_key *key,
	const struct nlattr *a, int rem)
	{
	struct deferred_action *da;

	if (!is_flow_key_valid(key)) {
	int err;

	err = ovs_flow_key_update(skb, key);
	if (err)
	return err;
	}
	BUG_ON(!is_flow_key_valid(key));

	if (!nla_is_last(a, rem)) {
	/* Recirc action is the not the last action
	* of the action list, need to clone the skb.
	*/
	skb = skb_clone(skb, GFP_ATOMIC);

	/* Skip the recirc action when out of memory, but
	* continue on with the rest of the action list.
	*/
	if (!skb)
	return 0;
	}

	da = add_deferred_actions(skb, key, NULL);
	if (da) {
	da->pkt_key.recirc_id = nla_get_u32(a);
	} else {
	kfree_skb(skb);

	if (net_ratelimit())
	pr_warn("%s: deferred action limit reached, drop recirc action\n",
	ovs_dp_name(dp));
	}

	return 0;
	}

	/* Execute a list of actions against 'skb'. */
	static int do_execute_actions(struct datapath dp, struct sk_buff skb,
	struct sw_flow_key *key,
	const struct nlattr *attr, int len)
	{
	/* Every output action needs a separate clone of 'skb', but the common
	* case is just a single output action, so that doing a clone and
	* then freeing the original skbuff is wasteful. So the following code
	* is slightly obscure just to avoid that.
	*/
	int prev_port = -1;
	const struct nlattr *a;
	int rem;

	for (a = attr, rem = len; rem > 0;
	a = nla_next(a, &rem)) {
	int err = 0;

	if (unlikely(prev_port != -1)) {
	struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC);

	if (out_skb)
	do_output(dp, out_skb, prev_port);

	prev_port = -1;
	}

	switch (nla_type(a)) {
	case OVS_ACTION_ATTR_OUTPUT:
	prev_port = nla_get_u32(a);
	break;

	case OVS_ACTION_ATTR_USERSPACE:
	output_userspace(dp, skb, key, a);
	break;

	case OVS_ACTION_ATTR_HASH:
	execute_hash(skb, key, a);
	break;

	case OVS_ACTION_ATTR_PUSH_MPLS:
	err = push_mpls(skb, key, nla_data(a));
	break;

	case OVS_ACTION_ATTR_POP_MPLS:
	err = pop_mpls(skb, key, nla_get_be16(a));
	break;

	case OVS_ACTION_ATTR_PUSH_VLAN:
	err = push_vlan(skb, key, nla_data(a));
	break;

	case OVS_ACTION_ATTR_POP_VLAN:
	err = pop_vlan(skb, key);
	break;

	case OVS_ACTION_ATTR_RECIRC:
	err = execute_recirc(dp, skb, key, a, rem);
	if (nla_is_last(a, rem)) {
	/* If this is the last action, the skb has
	* been consumed or freed.
	* Return immediately.
	*/
	return err;
	}
	break;

	case OVS_ACTION_ATTR_SET:
	err = execute_set_action(skb, key, nla_data(a));
	break;

	case OVS_ACTION_ATTR_SAMPLE:
	err = sample(dp, skb, key, a);
	break;
	}

	if (unlikely(err)) {
	kfree_skb(skb);
	return err;
	}
	}

	if (prev_port != -1)
	do_output(dp, skb, prev_port);
	else
	consume_skb(skb);

	return 0;
	}

	static void process_deferred_actions(struct datapath *dp)
	{
	struct action_fifo *fifo = this_cpu_ptr(action_fifos);

	/* Do not touch the FIFO in case there is no deferred actions. */
	if (action_fifo_is_empty(fifo))
	return;

	/* Finishing executing all deferred actions. */
	do {
	struct deferred_action *da = action_fifo_get(fifo);
	struct sk_buff *skb = da->skb;
	struct sw_flow_key *key = &da->pkt_key;
	const struct nlattr *actions = da->actions;

	if (actions)
	do_execute_actions(dp, skb, key, actions,
	nla_len(actions));
	else
	ovs_dp_process_packet(skb, key);
	} while (!action_fifo_is_empty(fifo));

	/* Reset FIFO for the next packet. */
	action_fifo_init(fifo);
	}

	/* Execute a list of actions against 'skb'. */
	int ovs_execute_actions(struct datapath dp, struct sk_buff skb,
	const struct sw_flow_actions *acts,
	struct sw_flow_key *key)
	{
	int level = this_cpu_read(exec_actions_level);
	int err;

	this_cpu_inc(exec_actions_level);
	OVS_CB(skb)->egress_tun_info = NULL;
	err = do_execute_actions(dp, skb, key,
	acts->actions, acts->actions_len);

	if (!level)
	process_deferred_actions(dp);

	this_cpu_dec(exec_actions_level);
	return err;
	}

	int action_fifos_init(void)
	{
	action_fifos = alloc_percpu(struct action_fifo);
	if (!action_fifos)
	return -ENOMEM;

	return 0;
	}

	void action_fifos_exit(void)
	{
	free_percpu(action_fifos);
	}