net/openvswitch/flow.c - arm/linux - Git at Google

 /*
  * 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
  */

 #include <linux/uaccess.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/if_ether.h>
 #include <linux/if_vlan.h>
 #include <net/llc_pdu.h>
 #include <linux/kernel.h>
 #include <linux/jhash.h>
 #include <linux/jiffies.h>
 #include <linux/llc.h>
 #include <linux/module.h>
 #include <linux/in.h>
 #include <linux/rcupdate.h>
 #include <linux/cpumask.h>
 #include <linux/if_arp.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
 #include <linux/mpls.h>
 #include <linux/sctp.h>
 #include <linux/smp.h>
 #include <linux/tcp.h>
 #include <linux/udp.h>
 #include <linux/icmp.h>
 #include <linux/icmpv6.h>
 #include <linux/rculist.h>
 #include <net/ip.h>
 #include <net/ip_tunnels.h>
 #include <net/ipv6.h>
 #include <net/mpls.h>
 #include <net/ndisc.h>

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

 u64 ovs_flow_used_time(unsigned long flow_jiffies)
 {
 	struct timespec cur_ts;
 	u64 cur_ms, idle_ms;

 	ktime_get_ts(&cur_ts);
 	idle_ms = jiffies_to_msecs(jiffies - flow_jiffies);
 	cur_ms = (u64)cur_ts.tv_sec * MSEC_PER_SEC +
 		 cur_ts.tv_nsec / NSEC_PER_MSEC;

 	return cur_ms - idle_ms;
 }

 #define TCP_FLAGS_BE16(tp) (*(__be16 *)&tcp_flag_word(tp) & htons(0x0FFF))

 void ovs_flow_stats_update(struct sw_flow *flow, __be16 tcp_flags,
 			   const struct sk_buff *skb)
 {
 	struct flow_stats *stats;
 	unsigned int cpu = smp_processor_id();
 	int len = skb->len + (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);

 	stats = rcu_dereference(flow->stats[cpu]);

 	/* Check if already have CPU-specific stats. */
 	if (likely(stats)) {
 		spin_lock(&stats->lock);
 		/* Mark if we write on the pre-allocated stats. */
 		if (cpu == 0 && unlikely(flow->stats_last_writer != cpu))
 			flow->stats_last_writer = cpu;
 	} else {
 		stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */
 		spin_lock(&stats->lock);

 		/* If the current CPU is the only writer on the
 		 * pre-allocated stats keep using them.
 		 */
 		if (unlikely(flow->stats_last_writer != cpu)) {
 			/* A previous locker may have already allocated the
 			 * stats, so we need to check again.  If CPU-specific
 			 * stats were already allocated, we update the pre-
 			 * allocated stats as we have already locked them.
 			 */
 			if (likely(flow->stats_last_writer != -1) &&
 			    likely(!rcu_access_pointer(flow->stats[cpu]))) {
 				/* Try to allocate CPU-specific stats. */
 				struct flow_stats *new_stats;

 				new_stats =
 					kmem_cache_alloc_node(flow_stats_cache,
 							      GFP_NOWAIT |
 							      __GFP_THISNODE |
 							      __GFP_NOWARN |
 							      __GFP_NOMEMALLOC,
 							      numa_node_id());
 				if (likely(new_stats)) {
 					new_stats->used = jiffies;
 					new_stats->packet_count = 1;
 					new_stats->byte_count = len;
 					new_stats->tcp_flags = tcp_flags;
 					spin_lock_init(&new_stats->lock);

 					rcu_assign_pointer(flow->stats[cpu],
 							   new_stats);
 					cpumask_set_cpu(cpu, &flow->cpu_used_mask);
 					goto unlock;
 				}
 			}
 			flow->stats_last_writer = cpu;
 		}
 	}

 	stats->used = jiffies;
 	stats->packet_count++;
 	stats->byte_count += len;
 	stats->tcp_flags |= tcp_flags;
 unlock:
 	spin_unlock(&stats->lock);
 }

 /* Must be called with rcu_read_lock or ovs_mutex. */
 void ovs_flow_stats_get(const struct sw_flow *flow,
 			struct ovs_flow_stats *ovs_stats,
 			unsigned long *used, __be16 *tcp_flags)
 {
 	int cpu;

 	*used = 0;
 	*tcp_flags = 0;
 	memset(ovs_stats, 0, sizeof(*ovs_stats));

 	/* We open code this to make sure cpu 0 is always considered */
 	for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
 		struct flow_stats *stats = rcu_dereference_ovsl(flow->stats[cpu]);

 		if (stats) {
 			/* Local CPU may write on non-local stats, so we must
 			 * block bottom-halves here.
 			 */
 			spin_lock_bh(&stats->lock);
 			if (!*used || time_after(stats->used, *used))
 				*used = stats->used;
 			*tcp_flags |= stats->tcp_flags;
 			ovs_stats->n_packets += stats->packet_count;
 			ovs_stats->n_bytes += stats->byte_count;
 			spin_unlock_bh(&stats->lock);
 		}
 	}
 }

 /* Called with ovs_mutex. */
 void ovs_flow_stats_clear(struct sw_flow *flow)
 {
 	int cpu;

 	/* We open code this to make sure cpu 0 is always considered */
 	for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
 		struct flow_stats *stats = ovsl_dereference(flow->stats[cpu]);

 		if (stats) {
 			spin_lock_bh(&stats->lock);
 			stats->used = 0;
 			stats->packet_count = 0;
 			stats->byte_count = 0;
 			stats->tcp_flags = 0;
 			spin_unlock_bh(&stats->lock);
 		}
 	}
 }

 static int check_header(struct sk_buff *skb, int len)
 {
 	if (unlikely(skb->len < len))
 		return -EINVAL;
 	if (unlikely(!pskb_may_pull(skb, len)))
 		return -ENOMEM;
 	return 0;
 }

 static bool arphdr_ok(struct sk_buff *skb)
 {
 	return pskb_may_pull(skb, skb_network_offset(skb) +
 				  sizeof(struct arp_eth_header));
 }

 static int check_iphdr(struct sk_buff *skb)
 {
 	unsigned int nh_ofs = skb_network_offset(skb);
 	unsigned int ip_len;
 	int err;

 	err = check_header(skb, nh_ofs + sizeof(struct iphdr));
 	if (unlikely(err))
 		return err;

 	ip_len = ip_hdrlen(skb);
 	if (unlikely(ip_len < sizeof(struct iphdr) ||
 		     skb->len < nh_ofs + ip_len))
 		return -EINVAL;

 	skb_set_transport_header(skb, nh_ofs + ip_len);
 	return 0;
 }

 static bool tcphdr_ok(struct sk_buff *skb)
 {
 	int th_ofs = skb_transport_offset(skb);
 	int tcp_len;

 	if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))))
 		return false;

 	tcp_len = tcp_hdrlen(skb);
 	if (unlikely(tcp_len < sizeof(struct tcphdr) ||
 		     skb->len < th_ofs + tcp_len))
 		return false;

 	return true;
 }

 static bool udphdr_ok(struct sk_buff *skb)
 {
 	return pskb_may_pull(skb, skb_transport_offset(skb) +
 				  sizeof(struct udphdr));
 }

 static bool sctphdr_ok(struct sk_buff *skb)
 {
 	return pskb_may_pull(skb, skb_transport_offset(skb) +
 				  sizeof(struct sctphdr));
 }

 static bool icmphdr_ok(struct sk_buff *skb)
 {
 	return pskb_may_pull(skb, skb_transport_offset(skb) +
 				  sizeof(struct icmphdr));
 }

 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
 {
 	unsigned int nh_ofs = skb_network_offset(skb);
 	unsigned int nh_len;
 	int payload_ofs;
 	struct ipv6hdr *nh;
 	uint8_t nexthdr;
 	__be16 frag_off;
 	int err;

 	err = check_header(skb, nh_ofs + sizeof(*nh));
 	if (unlikely(err))
 		return err;

 	nh = ipv6_hdr(skb);
 	nexthdr = nh->nexthdr;
 	payload_ofs = (u8 *)(nh + 1) - skb->data;

 	key->ip.proto = NEXTHDR_NONE;
 	key->ip.tos = ipv6_get_dsfield(nh);
 	key->ip.ttl = nh->hop_limit;
 	key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
 	key->ipv6.addr.src = nh->saddr;
 	key->ipv6.addr.dst = nh->daddr;

 	payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off);

 	if (frag_off) {
 		if (frag_off & htons(~0x7))
 			key->ip.frag = OVS_FRAG_TYPE_LATER;
 		else
 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
 	} else {
 		key->ip.frag = OVS_FRAG_TYPE_NONE;
 	}

 	/* Delayed handling of error in ipv6_skip_exthdr() as it
 	 * always sets frag_off to a valid value which may be
 	 * used to set key->ip.frag above.
 	 */
 	if (unlikely(payload_ofs < 0))
 		return -EPROTO;

 	nh_len = payload_ofs - nh_ofs;
 	skb_set_transport_header(skb, nh_ofs + nh_len);
 	key->ip.proto = nexthdr;
 	return nh_len;
 }

 static bool icmp6hdr_ok(struct sk_buff *skb)
 {
 	return pskb_may_pull(skb, skb_transport_offset(skb) +
 				  sizeof(struct icmp6hdr));
 }

 /**
  * Parse vlan tag from vlan header.
  * Returns ERROR on memory error.
  * Returns 0 if it encounters a non-vlan or incomplete packet.
  * Returns 1 after successfully parsing vlan tag.
  */
 static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh,
 			  bool untag_vlan)
 {
 	struct vlan_head *vh = (struct vlan_head *)skb->data;

 	if (likely(!eth_type_vlan(vh->tpid)))
 		return 0;

 	if (unlikely(skb->len < sizeof(struct vlan_head) + sizeof(__be16)))
 		return 0;

 	if (unlikely(!pskb_may_pull(skb, sizeof(struct vlan_head) +
 				 sizeof(__be16))))
 		return -ENOMEM;

 	vh = (struct vlan_head *)skb->data;
 	key_vh->tci = vh->tci | htons(VLAN_TAG_PRESENT);
 	key_vh->tpid = vh->tpid;

 	if (unlikely(untag_vlan)) {
 		int offset = skb->data - skb_mac_header(skb);
 		u16 tci;
 		int err;

 		__skb_push(skb, offset);
 		err = __skb_vlan_pop(skb, &tci);
 		__skb_pull(skb, offset);
 		if (err)
 			return err;
 		__vlan_hwaccel_put_tag(skb, key_vh->tpid, tci);
 	} else {
 		__skb_pull(skb, sizeof(struct vlan_head));
 	}
 	return 1;
 }

 static void clear_vlan(struct sw_flow_key *key)
 {
 	key->eth.vlan.tci = 0;
 	key->eth.vlan.tpid = 0;
 	key->eth.cvlan.tci = 0;
 	key->eth.cvlan.tpid = 0;
 }

 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 {
 	int res;

 	if (skb_vlan_tag_present(skb)) {
 		key->eth.vlan.tci = htons(skb->vlan_tci);
 		key->eth.vlan.tpid = skb->vlan_proto;
 	} else {
 		/* Parse outer vlan tag in the non-accelerated case. */
 		res = parse_vlan_tag(skb, &key->eth.vlan, true);
 		if (res <= 0)
 			return res;
 	}

 	/* Parse inner vlan tag. */
 	res = parse_vlan_tag(skb, &key->eth.cvlan, false);
 	if (res <= 0)
 		return res;

 	return 0;
 }

 static __be16 parse_ethertype(struct sk_buff *skb)
 {
 	struct llc_snap_hdr {
 		u8  dsap;  /* Always 0xAA */
 		u8  ssap;  /* Always 0xAA */
 		u8  ctrl;
 		u8  oui[3];
 		__be16 ethertype;
 	};
 	struct llc_snap_hdr *llc;
 	__be16 proto;

 	proto = *(__be16 *) skb->data;
 	__skb_pull(skb, sizeof(__be16));

 	if (eth_proto_is_802_3(proto))
 		return proto;

 	if (skb->len < sizeof(struct llc_snap_hdr))
 		return htons(ETH_P_802_2);

 	if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
 		return htons(0);

 	llc = (struct llc_snap_hdr *) skb->data;
 	if (llc->dsap != LLC_SAP_SNAP ||
 	    llc->ssap != LLC_SAP_SNAP ||
 	    (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
 		return htons(ETH_P_802_2);

 	__skb_pull(skb, sizeof(struct llc_snap_hdr));

 	if (eth_proto_is_802_3(llc->ethertype))
 		return llc->ethertype;

 	return htons(ETH_P_802_2);
 }

 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
 			int nh_len)
 {
 	struct icmp6hdr *icmp = icmp6_hdr(skb);

 	/* The ICMPv6 type and code fields use the 16-bit transport port
 	 * fields, so we need to store them in 16-bit network byte order.
 	 */
 	key->tp.src = htons(icmp->icmp6_type);
 	key->tp.dst = htons(icmp->icmp6_code);
 	memset(&key->ipv6.nd, 0, sizeof(key->ipv6.nd));

 	if (icmp->icmp6_code == 0 &&
 	    (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
 	     icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
 		int icmp_len = skb->len - skb_transport_offset(skb);
 		struct nd_msg *nd;
 		int offset;

 		/* In order to process neighbor discovery options, we need the
 		 * entire packet.
 		 */
 		if (unlikely(icmp_len < sizeof(*nd)))
 			return 0;

 		if (unlikely(skb_linearize(skb)))
 			return -ENOMEM;

 		nd = (struct nd_msg *)skb_transport_header(skb);
 		key->ipv6.nd.target = nd->target;

 		icmp_len -= sizeof(*nd);
 		offset = 0;
 		while (icmp_len >= 8) {
 			struct nd_opt_hdr *nd_opt =
 				 (struct nd_opt_hdr *)(nd->opt + offset);
 			int opt_len = nd_opt->nd_opt_len * 8;

 			if (unlikely(!opt_len || opt_len > icmp_len))
 				return 0;

 			/* Store the link layer address if the appropriate
 			 * option is provided.  It is considered an error if
 			 * the same link layer option is specified twice.
 			 */
 			if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
 			    && opt_len == 8) {
 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
 					goto invalid;
 				ether_addr_copy(key->ipv6.nd.sll,
 						&nd->opt[offset+sizeof(*nd_opt)]);
 			} else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
 				   && opt_len == 8) {
 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
 					goto invalid;
 				ether_addr_copy(key->ipv6.nd.tll,
 						&nd->opt[offset+sizeof(*nd_opt)]);
 			}

 			icmp_len -= opt_len;
 			offset += opt_len;
 		}
 	}

 	return 0;

 invalid:
 	memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
 	memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
 	memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));

 	return 0;
 }

 /**
  * key_extract - extracts a flow key from an Ethernet frame.
  * @skb: sk_buff that contains the frame, with skb->data pointing to the
  * Ethernet header
  * @key: output flow key
  *
  * The caller must ensure that skb->len >= ETH_HLEN.
  *
  * Returns 0 if successful, otherwise a negative errno value.
  *
  * Initializes @skb header fields as follows:
  *
  *    - skb->mac_header: the L2 header.
  *
  *    - skb->network_header: just past the L2 header, or just past the
  *      VLAN header, to the first byte of the L2 payload.
  *
  *    - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
  *      on output, then just past the IP header, if one is present and
  *      of a correct length, otherwise the same as skb->network_header.
  *      For other key->eth.type values it is left untouched.
  *
  *    - skb->protocol: the type of the data starting at skb->network_header.
  *      Equals to key->eth.type.
  */
 static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
 {
 	int error;
 	struct ethhdr *eth;

 	/* Flags are always used as part of stats */
 	key->tp.flags = 0;

 	skb_reset_mac_header(skb);

 	/* Link layer. */
 	clear_vlan(key);
 	if (ovs_key_mac_proto(key) == MAC_PROTO_NONE) {
 		if (unlikely(eth_type_vlan(skb->protocol)))
 			return -EINVAL;

 		skb_reset_network_header(skb);
 	} else {
 		eth = eth_hdr(skb);
 		ether_addr_copy(key->eth.src, eth->h_source);
 		ether_addr_copy(key->eth.dst, eth->h_dest);

 		__skb_pull(skb, 2 * ETH_ALEN);
 		/* We are going to push all headers that we pull, so no need to
 		* update skb->csum here.
 		*/

 		if (unlikely(parse_vlan(skb, key)))
 			return -ENOMEM;

 		skb->protocol = parse_ethertype(skb);
 		if (unlikely(skb->protocol == htons(0)))
 			return -ENOMEM;

 		skb_reset_network_header(skb);
 		__skb_push(skb, skb->data - skb_mac_header(skb));
 	}
 	skb_reset_mac_len(skb);
 	key->eth.type = skb->protocol;

 	/* Network layer. */
 	if (key->eth.type == htons(ETH_P_IP)) {
 		struct iphdr *nh;
 		__be16 offset;

 		error = check_iphdr(skb);
 		if (unlikely(error)) {
 			memset(&key->ip, 0, sizeof(key->ip));
 			memset(&key->ipv4, 0, sizeof(key->ipv4));
 			if (error == -EINVAL) {
 				skb->transport_header = skb->network_header;
 				error = 0;
 			}
 			return error;
 		}

 		nh = ip_hdr(skb);
 		key->ipv4.addr.src = nh->saddr;
 		key->ipv4.addr.dst = nh->daddr;

 		key->ip.proto = nh->protocol;
 		key->ip.tos = nh->tos;
 		key->ip.ttl = nh->ttl;

 		offset = nh->frag_off & htons(IP_OFFSET);
 		if (offset) {
 			key->ip.frag = OVS_FRAG_TYPE_LATER;
 			return 0;
 		}
 		if (nh->frag_off & htons(IP_MF))
 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
 		else
 			key->ip.frag = OVS_FRAG_TYPE_NONE;

 		/* Transport layer. */
 		if (key->ip.proto == IPPROTO_TCP) {
 			if (tcphdr_ok(skb)) {
 				struct tcphdr *tcp = tcp_hdr(skb);
 				key->tp.src = tcp->source;
 				key->tp.dst = tcp->dest;
 				key->tp.flags = TCP_FLAGS_BE16(tcp);
 			} else {
 				memset(&key->tp, 0, sizeof(key->tp));
 			}

 		} else if (key->ip.proto == IPPROTO_UDP) {
 			if (udphdr_ok(skb)) {
 				struct udphdr *udp = udp_hdr(skb);
 				key->tp.src = udp->source;
 				key->tp.dst = udp->dest;
 			} else {
 				memset(&key->tp, 0, sizeof(key->tp));
 			}
 		} else if (key->ip.proto == IPPROTO_SCTP) {
 			if (sctphdr_ok(skb)) {
 				struct sctphdr *sctp = sctp_hdr(skb);
 				key->tp.src = sctp->source;
 				key->tp.dst = sctp->dest;
 			} else {
 				memset(&key->tp, 0, sizeof(key->tp));
 			}
 		} else if (key->ip.proto == IPPROTO_ICMP) {
 			if (icmphdr_ok(skb)) {
 				struct icmphdr *icmp = icmp_hdr(skb);
 				/* The ICMP type and code fields use the 16-bit
 				 * transport port fields, so we need to store
 				 * them in 16-bit network byte order. */
 				key->tp.src = htons(icmp->type);
 				key->tp.dst = htons(icmp->code);
 			} else {
 				memset(&key->tp, 0, sizeof(key->tp));
 			}
 		}

 	} else if (key->eth.type == htons(ETH_P_ARP) ||
 		   key->eth.type == htons(ETH_P_RARP)) {
 		struct arp_eth_header *arp;
 		bool arp_available = arphdr_ok(skb);

 		arp = (struct arp_eth_header *)skb_network_header(skb);

 		if (arp_available &&
 		    arp->ar_hrd == htons(ARPHRD_ETHER) &&
 		    arp->ar_pro == htons(ETH_P_IP) &&
 		    arp->ar_hln == ETH_ALEN &&
 		    arp->ar_pln == 4) {

 			/* We only match on the lower 8 bits of the opcode. */
 			if (ntohs(arp->ar_op) <= 0xff)
 				key->ip.proto = ntohs(arp->ar_op);
 			else
 				key->ip.proto = 0;

 			memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
 			memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
 			ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha);
 			ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha);
 		} else {
 			memset(&key->ip, 0, sizeof(key->ip));
 			memset(&key->ipv4, 0, sizeof(key->ipv4));
 		}
 	} else if (eth_p_mpls(key->eth.type)) {
 		size_t stack_len = MPLS_HLEN;

 		skb_set_inner_network_header(skb, skb->mac_len);
 		while (1) {
 			__be32 lse;

 			error = check_header(skb, skb->mac_len + stack_len);
 			if (unlikely(error))
 				return 0;

 			memcpy(&lse, skb_inner_network_header(skb), MPLS_HLEN);

 			if (stack_len == MPLS_HLEN)
 				memcpy(&key->mpls.top_lse, &lse, MPLS_HLEN);

 			skb_set_inner_network_header(skb, skb->mac_len + stack_len);
 			if (lse & htonl(MPLS_LS_S_MASK))
 				break;

 			stack_len += MPLS_HLEN;
 		}
 	} else if (key->eth.type == htons(ETH_P_IPV6)) {
 		int nh_len;             /* IPv6 Header + Extensions */

 		nh_len = parse_ipv6hdr(skb, key);
 		if (unlikely(nh_len < 0)) {
 			switch (nh_len) {
 			case -EINVAL:
 				memset(&key->ip, 0, sizeof(key->ip));
 				memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr));
 				/* fall-through */
 			case -EPROTO:
 				skb->transport_header = skb->network_header;
 				error = 0;
 				break;
 			default:
 				error = nh_len;
 			}
 			return error;
 		}

 		if (key->ip.frag == OVS_FRAG_TYPE_LATER)
 			return 0;
 		/* Transport layer. */
 		if (key->ip.proto == NEXTHDR_TCP) {
 			if (tcphdr_ok(skb)) {
 				struct tcphdr *tcp = tcp_hdr(skb);
 				key->tp.src = tcp->source;
 				key->tp.dst = tcp->dest;
 				key->tp.flags = TCP_FLAGS_BE16(tcp);
 			} else {
 				memset(&key->tp, 0, sizeof(key->tp));
 			}
 		} else if (key->ip.proto == NEXTHDR_UDP) {
 			if (udphdr_ok(skb)) {
 				struct udphdr *udp = udp_hdr(skb);
 				key->tp.src = udp->source;
 				key->tp.dst = udp->dest;
 			} else {
 				memset(&key->tp, 0, sizeof(key->tp));
 			}
 		} else if (key->ip.proto == NEXTHDR_SCTP) {
 			if (sctphdr_ok(skb)) {
 				struct sctphdr *sctp = sctp_hdr(skb);
 				key->tp.src = sctp->source;
 				key->tp.dst = sctp->dest;
 			} else {
 				memset(&key->tp, 0, sizeof(key->tp));
 			}
 		} else if (key->ip.proto == NEXTHDR_ICMP) {
 			if (icmp6hdr_ok(skb)) {
 				error = parse_icmpv6(skb, key, nh_len);
 				if (error)
 					return error;
 			} else {
 				memset(&key->tp, 0, sizeof(key->tp));
 			}
 		}
 	}
 	return 0;
 }

 int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key)
 {
 	int res;

 	res = key_extract(skb, key);
 	if (!res)
 		key->mac_proto &= ~SW_FLOW_KEY_INVALID;

 	return res;
 }

 static int key_extract_mac_proto(struct sk_buff *skb)
 {
 	switch (skb->dev->type) {
 	case ARPHRD_ETHER:
 		return MAC_PROTO_ETHERNET;
 	case ARPHRD_NONE:
 		if (skb->protocol == htons(ETH_P_TEB))
 			return MAC_PROTO_ETHERNET;
 		return MAC_PROTO_NONE;
 	}
 	WARN_ON_ONCE(1);
 	return -EINVAL;
 }

 int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
 			 struct sk_buff *skb, struct sw_flow_key *key)
 {
 	int res, err;

 	/* Extract metadata from packet. */
 	if (tun_info) {
 		key->tun_proto = ip_tunnel_info_af(tun_info);
 		memcpy(&key->tun_key, &tun_info->key, sizeof(key->tun_key));

 		if (tun_info->options_len) {
 			BUILD_BUG_ON((1 << (sizeof(tun_info->options_len) *
 						   8)) - 1
 					> sizeof(key->tun_opts));

 			ip_tunnel_info_opts_get(TUN_METADATA_OPTS(key, tun_info->options_len),
 						tun_info);
 			key->tun_opts_len = tun_info->options_len;
 		} else {
 			key->tun_opts_len = 0;
 		}
 	} else  {
 		key->tun_proto = 0;
 		key->tun_opts_len = 0;
 		memset(&key->tun_key, 0, sizeof(key->tun_key));
 	}

 	key->phy.priority = skb->priority;
 	key->phy.in_port = OVS_CB(skb)->input_vport->port_no;
 	key->phy.skb_mark = skb->mark;
 	key->ovs_flow_hash = 0;
 	res = key_extract_mac_proto(skb);
 	if (res < 0)
 		return res;
 	key->mac_proto = res;
 	key->recirc_id = 0;

 	err = key_extract(skb, key);
 	if (!err)
 		ovs_ct_fill_key(skb, key);   /* Must be after key_extract(). */
 	return err;
 }

 int ovs_flow_key_extract_userspace(struct net *net, const struct nlattr *attr,
 				   struct sk_buff *skb,
 				   struct sw_flow_key *key, bool log)
 {
 	const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
 	u64 attrs = 0;
 	int err;

 	err = parse_flow_nlattrs(attr, a, &attrs, log);
 	if (err)
 		return -EINVAL;

 	/* Extract metadata from netlink attributes. */
 	err = ovs_nla_get_flow_metadata(net, a, attrs, key, log);
 	if (err)
 		return err;

 	/* key_extract assumes that skb->protocol is set-up for
 	 * layer 3 packets which is the case for other callers,
 	 * in particular packets received from the network stack.
 	 * Here the correct value can be set from the metadata
 	 * extracted above.
 	 * For L2 packet key eth type would be zero. skb protocol
 	 * would be set to correct value later during key-extact.
 	 */

 	skb->protocol = key->eth.type;
 	err = key_extract(skb, key);
 	if (err)
 		return err;

 	/* Check that we have conntrack original direction tuple metadata only
 	 * for packets for which it makes sense.  Otherwise the key may be
 	 * corrupted due to overlapping key fields.
 	 */
 	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4) &&
 	    key->eth.type != htons(ETH_P_IP))
 		return -EINVAL;
 	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6) &&
 	    (key->eth.type != htons(ETH_P_IPV6) ||
 	     sw_flow_key_is_nd(key)))
 		return -EINVAL;

 	return 0;
 }
	/*
	* 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
	*/

	#include <linux/uaccess.h>
	#include <linux/netdevice.h>
	#include <linux/etherdevice.h>
	#include <linux/if_ether.h>
	#include <linux/if_vlan.h>
	#include <net/llc_pdu.h>
	#include <linux/kernel.h>
	#include <linux/jhash.h>
	#include <linux/jiffies.h>
	#include <linux/llc.h>
	#include <linux/module.h>
	#include <linux/in.h>
	#include <linux/rcupdate.h>
	#include <linux/cpumask.h>
	#include <linux/if_arp.h>
	#include <linux/ip.h>
	#include <linux/ipv6.h>
	#include <linux/mpls.h>
	#include <linux/sctp.h>
	#include <linux/smp.h>
	#include <linux/tcp.h>
	#include <linux/udp.h>
	#include <linux/icmp.h>
	#include <linux/icmpv6.h>
	#include <linux/rculist.h>
	#include <net/ip.h>
	#include <net/ip_tunnels.h>
	#include <net/ipv6.h>
	#include <net/mpls.h>
	#include <net/ndisc.h>

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

	u64 ovs_flow_used_time(unsigned long flow_jiffies)
	{
	struct timespec cur_ts;
	u64 cur_ms, idle_ms;

	ktime_get_ts(&cur_ts);
	idle_ms = jiffies_to_msecs(jiffies - flow_jiffies);
	cur_ms = (u64)cur_ts.tv_sec * MSEC_PER_SEC +
	cur_ts.tv_nsec / NSEC_PER_MSEC;

	return cur_ms - idle_ms;
	}

	#define TCP_FLAGS_BE16(tp) ((__be16 )&tcp_flag_word(tp) & htons(0x0FFF))

	void ovs_flow_stats_update(struct sw_flow *flow, __be16 tcp_flags,
	const struct sk_buff *skb)
	{
	struct flow_stats *stats;
	unsigned int cpu = smp_processor_id();
	int len = skb->len + (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);

	stats = rcu_dereference(flow->stats[cpu]);

	/* Check if already have CPU-specific stats. */
	if (likely(stats)) {
	spin_lock(&stats->lock);
	/* Mark if we write on the pre-allocated stats. */
	if (cpu == 0 && unlikely(flow->stats_last_writer != cpu))
	flow->stats_last_writer = cpu;
	} else {
	stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */
	spin_lock(&stats->lock);

	/* If the current CPU is the only writer on the
	* pre-allocated stats keep using them.
	*/
	if (unlikely(flow->stats_last_writer != cpu)) {
	/* A previous locker may have already allocated the
	* stats, so we need to check again. If CPU-specific
	* stats were already allocated, we update the pre-
	* allocated stats as we have already locked them.
	*/
	if (likely(flow->stats_last_writer != -1) &&
	likely(!rcu_access_pointer(flow->stats[cpu]))) {
	/* Try to allocate CPU-specific stats. */
	struct flow_stats *new_stats;

	new_stats =
	kmem_cache_alloc_node(flow_stats_cache,
	GFP_NOWAIT \|
	__GFP_THISNODE \|
	__GFP_NOWARN \|
	__GFP_NOMEMALLOC,
	numa_node_id());
	if (likely(new_stats)) {
	new_stats->used = jiffies;
	new_stats->packet_count = 1;
	new_stats->byte_count = len;
	new_stats->tcp_flags = tcp_flags;
	spin_lock_init(&new_stats->lock);

	rcu_assign_pointer(flow->stats[cpu],
	new_stats);
	cpumask_set_cpu(cpu, &flow->cpu_used_mask);
	goto unlock;
	}
	}
	flow->stats_last_writer = cpu;
	}
	}

	stats->used = jiffies;
	stats->packet_count++;
	stats->byte_count += len;
	stats->tcp_flags \|= tcp_flags;
	unlock:
	spin_unlock(&stats->lock);
	}

	/* Must be called with rcu_read_lock or ovs_mutex. */
	void ovs_flow_stats_get(const struct sw_flow *flow,
	struct ovs_flow_stats *ovs_stats,
	unsigned long used, __be16 tcp_flags)
	{
	int cpu;

	*used = 0;
	*tcp_flags = 0;
	memset(ovs_stats, 0, sizeof(*ovs_stats));

	/* We open code this to make sure cpu 0 is always considered */
	for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
	struct flow_stats *stats = rcu_dereference_ovsl(flow->stats[cpu]);

	if (stats) {
	/* Local CPU may write on non-local stats, so we must
	* block bottom-halves here.
	*/
	spin_lock_bh(&stats->lock);
	if (!used \|\| time_after(stats->used, used))
	*used = stats->used;
	*tcp_flags \|= stats->tcp_flags;
	ovs_stats->n_packets += stats->packet_count;
	ovs_stats->n_bytes += stats->byte_count;
	spin_unlock_bh(&stats->lock);
	}
	}
	}

	/* Called with ovs_mutex. */
	void ovs_flow_stats_clear(struct sw_flow *flow)
	{
	int cpu;

	/* We open code this to make sure cpu 0 is always considered */
	for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
	struct flow_stats *stats = ovsl_dereference(flow->stats[cpu]);

	if (stats) {
	spin_lock_bh(&stats->lock);
	stats->used = 0;
	stats->packet_count = 0;
	stats->byte_count = 0;
	stats->tcp_flags = 0;
	spin_unlock_bh(&stats->lock);
	}
	}
	}

	static int check_header(struct sk_buff *skb, int len)
	{
	if (unlikely(skb->len < len))
	return -EINVAL;
	if (unlikely(!pskb_may_pull(skb, len)))
	return -ENOMEM;
	return 0;
	}

	static bool arphdr_ok(struct sk_buff *skb)
	{
	return pskb_may_pull(skb, skb_network_offset(skb) +
	sizeof(struct arp_eth_header));
	}

	static int check_iphdr(struct sk_buff *skb)
	{
	unsigned int nh_ofs = skb_network_offset(skb);
	unsigned int ip_len;
	int err;

	err = check_header(skb, nh_ofs + sizeof(struct iphdr));
	if (unlikely(err))
	return err;

	ip_len = ip_hdrlen(skb);
	if (unlikely(ip_len < sizeof(struct iphdr) \|\|
	skb->len < nh_ofs + ip_len))
	return -EINVAL;

	skb_set_transport_header(skb, nh_ofs + ip_len);
	return 0;
	}

	static bool tcphdr_ok(struct sk_buff *skb)
	{
	int th_ofs = skb_transport_offset(skb);
	int tcp_len;

	if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))))
	return false;

	tcp_len = tcp_hdrlen(skb);
	if (unlikely(tcp_len < sizeof(struct tcphdr) \|\|
	skb->len < th_ofs + tcp_len))
	return false;

	return true;
	}

	static bool udphdr_ok(struct sk_buff *skb)
	{
	return pskb_may_pull(skb, skb_transport_offset(skb) +
	sizeof(struct udphdr));
	}

	static bool sctphdr_ok(struct sk_buff *skb)
	{
	return pskb_may_pull(skb, skb_transport_offset(skb) +
	sizeof(struct sctphdr));
	}

	static bool icmphdr_ok(struct sk_buff *skb)
	{
	return pskb_may_pull(skb, skb_transport_offset(skb) +
	sizeof(struct icmphdr));
	}

	static int parse_ipv6hdr(struct sk_buff skb, struct sw_flow_key key)
	{
	unsigned int nh_ofs = skb_network_offset(skb);
	unsigned int nh_len;
	int payload_ofs;
	struct ipv6hdr *nh;
	uint8_t nexthdr;
	__be16 frag_off;
	int err;

	err = check_header(skb, nh_ofs + sizeof(*nh));
	if (unlikely(err))
	return err;

	nh = ipv6_hdr(skb);
	nexthdr = nh->nexthdr;
	payload_ofs = (u8 *)(nh + 1) - skb->data;

	key->ip.proto = NEXTHDR_NONE;
	key->ip.tos = ipv6_get_dsfield(nh);
	key->ip.ttl = nh->hop_limit;
	key->ipv6.label = (__be32 )nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
	key->ipv6.addr.src = nh->saddr;
	key->ipv6.addr.dst = nh->daddr;

	payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off);

	if (frag_off) {
	if (frag_off & htons(~0x7))
	key->ip.frag = OVS_FRAG_TYPE_LATER;
	else
	key->ip.frag = OVS_FRAG_TYPE_FIRST;
	} else {
	key->ip.frag = OVS_FRAG_TYPE_NONE;
	}

	/* Delayed handling of error in ipv6_skip_exthdr() as it
	* always sets frag_off to a valid value which may be
	* used to set key->ip.frag above.
	*/
	if (unlikely(payload_ofs < 0))
	return -EPROTO;

	nh_len = payload_ofs - nh_ofs;
	skb_set_transport_header(skb, nh_ofs + nh_len);
	key->ip.proto = nexthdr;
	return nh_len;
	}

	static bool icmp6hdr_ok(struct sk_buff *skb)
	{
	return pskb_may_pull(skb, skb_transport_offset(skb) +
	sizeof(struct icmp6hdr));
	}

	/**
	* Parse vlan tag from vlan header.
	* Returns ERROR on memory error.
	* Returns 0 if it encounters a non-vlan or incomplete packet.
	* Returns 1 after successfully parsing vlan tag.
	*/
	static int parse_vlan_tag(struct sk_buff skb, struct vlan_head key_vh,
	bool untag_vlan)
	{
	struct vlan_head vh = (struct vlan_head )skb->data;

	if (likely(!eth_type_vlan(vh->tpid)))
	return 0;

	if (unlikely(skb->len < sizeof(struct vlan_head) + sizeof(__be16)))
	return 0;

	if (unlikely(!pskb_may_pull(skb, sizeof(struct vlan_head) +
	sizeof(__be16))))
	return -ENOMEM;

	vh = (struct vlan_head *)skb->data;
	key_vh->tci = vh->tci \| htons(VLAN_TAG_PRESENT);
	key_vh->tpid = vh->tpid;

	if (unlikely(untag_vlan)) {
	int offset = skb->data - skb_mac_header(skb);
	u16 tci;
	int err;

	__skb_push(skb, offset);
	err = __skb_vlan_pop(skb, &tci);
	__skb_pull(skb, offset);
	if (err)
	return err;
	__vlan_hwaccel_put_tag(skb, key_vh->tpid, tci);
	} else {
	__skb_pull(skb, sizeof(struct vlan_head));
	}
	return 1;
	}

	static void clear_vlan(struct sw_flow_key *key)
	{
	key->eth.vlan.tci = 0;
	key->eth.vlan.tpid = 0;
	key->eth.cvlan.tci = 0;
	key->eth.cvlan.tpid = 0;
	}

	static int parse_vlan(struct sk_buff skb, struct sw_flow_key key)
	{
	int res;

	if (skb_vlan_tag_present(skb)) {
	key->eth.vlan.tci = htons(skb->vlan_tci);
	key->eth.vlan.tpid = skb->vlan_proto;
	} else {
	/* Parse outer vlan tag in the non-accelerated case. */
	res = parse_vlan_tag(skb, &key->eth.vlan, true);
	if (res <= 0)
	return res;
	}

	/* Parse inner vlan tag. */
	res = parse_vlan_tag(skb, &key->eth.cvlan, false);
	if (res <= 0)
	return res;

	return 0;
	}

	static __be16 parse_ethertype(struct sk_buff *skb)
	{
	struct llc_snap_hdr {
	u8 dsap; /* Always 0xAA */
	u8 ssap; /* Always 0xAA */
	u8 ctrl;
	u8 oui[3];
	__be16 ethertype;
	};
	struct llc_snap_hdr *llc;
	__be16 proto;

	proto = (__be16 ) skb->data;
	__skb_pull(skb, sizeof(__be16));

	if (eth_proto_is_802_3(proto))
	return proto;

	if (skb->len < sizeof(struct llc_snap_hdr))
	return htons(ETH_P_802_2);

	if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
	return htons(0);

	llc = (struct llc_snap_hdr *) skb->data;
	if (llc->dsap != LLC_SAP_SNAP \|\|
	llc->ssap != LLC_SAP_SNAP \|\|
	(llc->oui[0] \| llc->oui[1] \| llc->oui[2]) != 0)
	return htons(ETH_P_802_2);

	__skb_pull(skb, sizeof(struct llc_snap_hdr));

	if (eth_proto_is_802_3(llc->ethertype))
	return llc->ethertype;

	return htons(ETH_P_802_2);
	}

	static int parse_icmpv6(struct sk_buff skb, struct sw_flow_key key,
	int nh_len)
	{
	struct icmp6hdr *icmp = icmp6_hdr(skb);

	/* The ICMPv6 type and code fields use the 16-bit transport port
	* fields, so we need to store them in 16-bit network byte order.
	*/
	key->tp.src = htons(icmp->icmp6_type);
	key->tp.dst = htons(icmp->icmp6_code);
	memset(&key->ipv6.nd, 0, sizeof(key->ipv6.nd));

	if (icmp->icmp6_code == 0 &&
	(icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION \|\|
	icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
	int icmp_len = skb->len - skb_transport_offset(skb);
	struct nd_msg *nd;
	int offset;

	/* In order to process neighbor discovery options, we need the
	* entire packet.
	*/
	if (unlikely(icmp_len < sizeof(*nd)))
	return 0;

	if (unlikely(skb_linearize(skb)))
	return -ENOMEM;

	nd = (struct nd_msg *)skb_transport_header(skb);
	key->ipv6.nd.target = nd->target;

	icmp_len -= sizeof(*nd);
	offset = 0;
	while (icmp_len >= 8) {
	struct nd_opt_hdr *nd_opt =
	(struct nd_opt_hdr *)(nd->opt + offset);
	int opt_len = nd_opt->nd_opt_len * 8;

	if (unlikely(!opt_len \|\| opt_len > icmp_len))
	return 0;

	/* Store the link layer address if the appropriate
	* option is provided. It is considered an error if
	* the same link layer option is specified twice.
	*/
	if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
	&& opt_len == 8) {
	if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
	goto invalid;
	ether_addr_copy(key->ipv6.nd.sll,
	&nd->opt[offset+sizeof(*nd_opt)]);
	} else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
	&& opt_len == 8) {
	if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
	goto invalid;
	ether_addr_copy(key->ipv6.nd.tll,
	&nd->opt[offset+sizeof(*nd_opt)]);
	}

	icmp_len -= opt_len;
	offset += opt_len;
	}
	}

	return 0;

	invalid:
	memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
	memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
	memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));

	return 0;
	}

	/**
	* key_extract - extracts a flow key from an Ethernet frame.
	* @skb: sk_buff that contains the frame, with skb->data pointing to the
	* Ethernet header
	* @key: output flow key
	*
	* The caller must ensure that skb->len >= ETH_HLEN.
	*
	* Returns 0 if successful, otherwise a negative errno value.
	*
	* Initializes @skb header fields as follows:
	*
	* - skb->mac_header: the L2 header.
	*
	* - skb->network_header: just past the L2 header, or just past the
	* VLAN header, to the first byte of the L2 payload.
	*
	* - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
	* on output, then just past the IP header, if one is present and
	* of a correct length, otherwise the same as skb->network_header.
	* For other key->eth.type values it is left untouched.
	*
	* - skb->protocol: the type of the data starting at skb->network_header.
	* Equals to key->eth.type.
	*/
	static int key_extract(struct sk_buff skb, struct sw_flow_key key)
	{
	int error;
	struct ethhdr *eth;

	/* Flags are always used as part of stats */
	key->tp.flags = 0;

	skb_reset_mac_header(skb);

	/* Link layer. */
	clear_vlan(key);
	if (ovs_key_mac_proto(key) == MAC_PROTO_NONE) {
	if (unlikely(eth_type_vlan(skb->protocol)))
	return -EINVAL;

	skb_reset_network_header(skb);
	} else {
	eth = eth_hdr(skb);
	ether_addr_copy(key->eth.src, eth->h_source);
	ether_addr_copy(key->eth.dst, eth->h_dest);

	__skb_pull(skb, 2 * ETH_ALEN);
	/* We are going to push all headers that we pull, so no need to
	* update skb->csum here.
	*/

	if (unlikely(parse_vlan(skb, key)))
	return -ENOMEM;

	skb->protocol = parse_ethertype(skb);
	if (unlikely(skb->protocol == htons(0)))
	return -ENOMEM;

	skb_reset_network_header(skb);
	__skb_push(skb, skb->data - skb_mac_header(skb));
	}
	skb_reset_mac_len(skb);
	key->eth.type = skb->protocol;

	/* Network layer. */
	if (key->eth.type == htons(ETH_P_IP)) {
	struct iphdr *nh;
	__be16 offset;

	error = check_iphdr(skb);
	if (unlikely(error)) {
	memset(&key->ip, 0, sizeof(key->ip));
	memset(&key->ipv4, 0, sizeof(key->ipv4));
	if (error == -EINVAL) {
	skb->transport_header = skb->network_header;
	error = 0;
	}
	return error;
	}

	nh = ip_hdr(skb);
	key->ipv4.addr.src = nh->saddr;
	key->ipv4.addr.dst = nh->daddr;

	key->ip.proto = nh->protocol;
	key->ip.tos = nh->tos;
	key->ip.ttl = nh->ttl;

	offset = nh->frag_off & htons(IP_OFFSET);
	if (offset) {
	key->ip.frag = OVS_FRAG_TYPE_LATER;
	return 0;
	}
	if (nh->frag_off & htons(IP_MF))
	key->ip.frag = OVS_FRAG_TYPE_FIRST;
	else
	key->ip.frag = OVS_FRAG_TYPE_NONE;

	/* Transport layer. */
	if (key->ip.proto == IPPROTO_TCP) {
	if (tcphdr_ok(skb)) {
	struct tcphdr *tcp = tcp_hdr(skb);
	key->tp.src = tcp->source;
	key->tp.dst = tcp->dest;
	key->tp.flags = TCP_FLAGS_BE16(tcp);
	} else {
	memset(&key->tp, 0, sizeof(key->tp));
	}

	} else if (key->ip.proto == IPPROTO_UDP) {
	if (udphdr_ok(skb)) {
	struct udphdr *udp = udp_hdr(skb);
	key->tp.src = udp->source;
	key->tp.dst = udp->dest;
	} else {
	memset(&key->tp, 0, sizeof(key->tp));
	}
	} else if (key->ip.proto == IPPROTO_SCTP) {
	if (sctphdr_ok(skb)) {
	struct sctphdr *sctp = sctp_hdr(skb);
	key->tp.src = sctp->source;
	key->tp.dst = sctp->dest;
	} else {
	memset(&key->tp, 0, sizeof(key->tp));
	}
	} else if (key->ip.proto == IPPROTO_ICMP) {
	if (icmphdr_ok(skb)) {
	struct icmphdr *icmp = icmp_hdr(skb);
	/* The ICMP type and code fields use the 16-bit
	* transport port fields, so we need to store
	* them in 16-bit network byte order. */
	key->tp.src = htons(icmp->type);
	key->tp.dst = htons(icmp->code);
	} else {
	memset(&key->tp, 0, sizeof(key->tp));
	}
	}

	} else if (key->eth.type == htons(ETH_P_ARP) \|\|
	key->eth.type == htons(ETH_P_RARP)) {
	struct arp_eth_header *arp;
	bool arp_available = arphdr_ok(skb);

	arp = (struct arp_eth_header *)skb_network_header(skb);

	if (arp_available &&
	arp->ar_hrd == htons(ARPHRD_ETHER) &&
	arp->ar_pro == htons(ETH_P_IP) &&
	arp->ar_hln == ETH_ALEN &&
	arp->ar_pln == 4) {

	/* We only match on the lower 8 bits of the opcode. */
	if (ntohs(arp->ar_op) <= 0xff)
	key->ip.proto = ntohs(arp->ar_op);
	else
	key->ip.proto = 0;

	memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
	memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
	ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha);
	ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha);
	} else {
	memset(&key->ip, 0, sizeof(key->ip));
	memset(&key->ipv4, 0, sizeof(key->ipv4));
	}
	} else if (eth_p_mpls(key->eth.type)) {
	size_t stack_len = MPLS_HLEN;

	skb_set_inner_network_header(skb, skb->mac_len);
	while (1) {
	__be32 lse;

	error = check_header(skb, skb->mac_len + stack_len);
	if (unlikely(error))
	return 0;

	memcpy(&lse, skb_inner_network_header(skb), MPLS_HLEN);

	if (stack_len == MPLS_HLEN)
	memcpy(&key->mpls.top_lse, &lse, MPLS_HLEN);

	skb_set_inner_network_header(skb, skb->mac_len + stack_len);
	if (lse & htonl(MPLS_LS_S_MASK))
	break;

	stack_len += MPLS_HLEN;
	}
	} else if (key->eth.type == htons(ETH_P_IPV6)) {
	int nh_len; /* IPv6 Header + Extensions */

	nh_len = parse_ipv6hdr(skb, key);
	if (unlikely(nh_len < 0)) {
	switch (nh_len) {
	case -EINVAL:
	memset(&key->ip, 0, sizeof(key->ip));
	memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr));
	/* fall-through */
	case -EPROTO:
	skb->transport_header = skb->network_header;
	error = 0;
	break;
	default:
	error = nh_len;
	}
	return error;
	}

	if (key->ip.frag == OVS_FRAG_TYPE_LATER)
	return 0;
	/* Transport layer. */
	if (key->ip.proto == NEXTHDR_TCP) {
	if (tcphdr_ok(skb)) {
	struct tcphdr *tcp = tcp_hdr(skb);
	key->tp.src = tcp->source;
	key->tp.dst = tcp->dest;
	key->tp.flags = TCP_FLAGS_BE16(tcp);
	} else {
	memset(&key->tp, 0, sizeof(key->tp));
	}
	} else if (key->ip.proto == NEXTHDR_UDP) {
	if (udphdr_ok(skb)) {
	struct udphdr *udp = udp_hdr(skb);
	key->tp.src = udp->source;
	key->tp.dst = udp->dest;
	} else {
	memset(&key->tp, 0, sizeof(key->tp));
	}
	} else if (key->ip.proto == NEXTHDR_SCTP) {
	if (sctphdr_ok(skb)) {
	struct sctphdr *sctp = sctp_hdr(skb);
	key->tp.src = sctp->source;
	key->tp.dst = sctp->dest;
	} else {
	memset(&key->tp, 0, sizeof(key->tp));
	}
	} else if (key->ip.proto == NEXTHDR_ICMP) {
	if (icmp6hdr_ok(skb)) {
	error = parse_icmpv6(skb, key, nh_len);
	if (error)
	return error;
	} else {
	memset(&key->tp, 0, sizeof(key->tp));
	}
	}
	}
	return 0;
	}

	int ovs_flow_key_update(struct sk_buff skb, struct sw_flow_key key)
	{
	int res;

	res = key_extract(skb, key);
	if (!res)
	key->mac_proto &= ~SW_FLOW_KEY_INVALID;

	return res;
	}

	static int key_extract_mac_proto(struct sk_buff *skb)
	{
	switch (skb->dev->type) {
	case ARPHRD_ETHER:
	return MAC_PROTO_ETHERNET;
	case ARPHRD_NONE:
	if (skb->protocol == htons(ETH_P_TEB))
	return MAC_PROTO_ETHERNET;
	return MAC_PROTO_NONE;
	}
	WARN_ON_ONCE(1);
	return -EINVAL;
	}

	int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
	struct sk_buff skb, struct sw_flow_key key)
	{
	int res, err;

	/* Extract metadata from packet. */
	if (tun_info) {
	key->tun_proto = ip_tunnel_info_af(tun_info);
	memcpy(&key->tun_key, &tun_info->key, sizeof(key->tun_key));

	if (tun_info->options_len) {
	BUILD_BUG_ON((1 << (sizeof(tun_info->options_len) *
	8)) - 1
	> sizeof(key->tun_opts));

	ip_tunnel_info_opts_get(TUN_METADATA_OPTS(key, tun_info->options_len),
	tun_info);
	key->tun_opts_len = tun_info->options_len;
	} else {
	key->tun_opts_len = 0;
	}
	} else {
	key->tun_proto = 0;
	key->tun_opts_len = 0;
	memset(&key->tun_key, 0, sizeof(key->tun_key));
	}

	key->phy.priority = skb->priority;
	key->phy.in_port = OVS_CB(skb)->input_vport->port_no;
	key->phy.skb_mark = skb->mark;
	key->ovs_flow_hash = 0;
	res = key_extract_mac_proto(skb);
	if (res < 0)
	return res;
	key->mac_proto = res;
	key->recirc_id = 0;

	err = key_extract(skb, key);
	if (!err)
	ovs_ct_fill_key(skb, key); /* Must be after key_extract(). */
	return err;
	}

	int ovs_flow_key_extract_userspace(struct net net, const struct nlattr attr,
	struct sk_buff *skb,
	struct sw_flow_key *key, bool log)
	{
	const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
	u64 attrs = 0;
	int err;

	err = parse_flow_nlattrs(attr, a, &attrs, log);
	if (err)
	return -EINVAL;

	/* Extract metadata from netlink attributes. */
	err = ovs_nla_get_flow_metadata(net, a, attrs, key, log);
	if (err)
	return err;

	/* key_extract assumes that skb->protocol is set-up for
	* layer 3 packets which is the case for other callers,
	* in particular packets received from the network stack.
	* Here the correct value can be set from the metadata
	* extracted above.
	* For L2 packet key eth type would be zero. skb protocol
	* would be set to correct value later during key-extact.
	*/

	skb->protocol = key->eth.type;
	err = key_extract(skb, key);
	if (err)
	return err;

	/* Check that we have conntrack original direction tuple metadata only
	* for packets for which it makes sense. Otherwise the key may be
	* corrupted due to overlapping key fields.
	*/
	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4) &&
	key->eth.type != htons(ETH_P_IP))
	return -EINVAL;
	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6) &&
	(key->eth.type != htons(ETH_P_IPV6) \|\|
	sw_flow_key_is_nd(key)))
	return -EINVAL;

	return 0;
	}