Rewind v3.13-rc3+ (78fd82238d0e5716) to v3.12

1 files changed, 1581 insertions, 24 deletions

diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index b409f52..410db90 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -45,38 +45,202 @@
 #include <net/ipv6.h>
 #include <net/ndisc.h>
 
-u64 ovs_flow_used_time(unsigned long flow_jiffies)
+static struct kmem_cache *flow_cache;
+
+static void ovs_sw_flow_mask_set(struct sw_flow_mask *mask,
+		struct sw_flow_key_range *range, u8 val);
+
+static void update_range__(struct sw_flow_match *match,
+			  size_t offset, size_t size, bool is_mask)
 {
-	struct timespec cur_ts;
-	u64 cur_ms, idle_ms;
+	struct sw_flow_key_range *range = NULL;
+	size_t start = rounddown(offset, sizeof(long));
+	size_t end = roundup(offset + size, sizeof(long));
+
+	if (!is_mask)
+		range = &match->range;
+	else if (match->mask)
+		range = &match->mask->range;
+
+	if (!range)
+		return;
+
+	if (range->start == range->end) {
+		range->start = start;
+		range->end = end;
+		return;
+	}
 
-	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;
+	if (range->start > start)
+		range->start = start;
 
-	return cur_ms - idle_ms;
+	if (range->end < end)
+		range->end = end;
 }
 
-#define TCP_FLAGS_BE16(tp) (*(__be16 *)&tcp_flag_word(tp) & htons(0x0FFF))
+#define SW_FLOW_KEY_PUT(match, field, value, is_mask) \
+	do { \
+		update_range__(match, offsetof(struct sw_flow_key, field),  \
+				     sizeof((match)->key->field), is_mask); \
+		if (is_mask) {						    \
+			if ((match)->mask)				    \
+				(match)->mask->key.field = value;	    \
+		} else {                                                    \
+			(match)->key->field = value;		            \
+		}                                                           \
+	} while (0)
+
+#define SW_FLOW_KEY_MEMCPY(match, field, value_p, len, is_mask) \
+	do { \
+		update_range__(match, offsetof(struct sw_flow_key, field),  \
+				len, is_mask);                              \
+		if (is_mask) {						    \
+			if ((match)->mask)				    \
+				memcpy(&(match)->mask->key.field, value_p, len);\
+		} else {                                                    \
+			memcpy(&(match)->key->field, value_p, len);         \
+		}                                                           \
+	} while (0)
+
+static u16 range_n_bytes(const struct sw_flow_key_range *range)
+{
+	return range->end - range->start;
+}
 
-void ovs_flow_used(struct sw_flow *flow, struct sk_buff *skb)
+void ovs_match_init(struct sw_flow_match *match,
+		    struct sw_flow_key *key,
+		    struct sw_flow_mask *mask)
 {
-	__be16 tcp_flags = 0;
+	memset(match, 0, sizeof(*match));
+	match->key = key;
+	match->mask = mask;
 
-	if ((flow->key.eth.type == htons(ETH_P_IP) ||
-	     flow->key.eth.type == htons(ETH_P_IPV6)) &&
-	    flow->key.ip.proto == IPPROTO_TCP &&
-	    likely(skb->len >= skb_transport_offset(skb) + sizeof(struct tcphdr))) {
-		tcp_flags = TCP_FLAGS_BE16(tcp_hdr(skb));
+	memset(key, 0, sizeof(*key));
+
+	if (mask) {
+		memset(&mask->key, 0, sizeof(mask->key));
+		mask->range.start = mask->range.end = 0;
 	}
+}
 
-	spin_lock(&flow->lock);
-	flow->used = jiffies;
-	flow->packet_count++;
-	flow->byte_count += skb->len;
-	flow->tcp_flags |= tcp_flags;
-	spin_unlock(&flow->lock);
+static bool ovs_match_validate(const struct sw_flow_match *match,
+		u64 key_attrs, u64 mask_attrs)
+{
+	u64 key_expected = 1 << OVS_KEY_ATTR_ETHERNET;
+	u64 mask_allowed = key_attrs;  /* At most allow all key attributes */
+
+	/* The following mask attributes allowed only if they
+	 * pass the validation tests. */
+	mask_allowed &= ~((1 << OVS_KEY_ATTR_IPV4)
+			| (1 << OVS_KEY_ATTR_IPV6)
+			| (1 << OVS_KEY_ATTR_TCP)
+			| (1 << OVS_KEY_ATTR_UDP)
+			| (1 << OVS_KEY_ATTR_SCTP)
+			| (1 << OVS_KEY_ATTR_ICMP)
+			| (1 << OVS_KEY_ATTR_ICMPV6)
+			| (1 << OVS_KEY_ATTR_ARP)
+			| (1 << OVS_KEY_ATTR_ND));
+
+	/* Always allowed mask fields. */
+	mask_allowed |= ((1 << OVS_KEY_ATTR_TUNNEL)
+		       | (1 << OVS_KEY_ATTR_IN_PORT)
+		       | (1 << OVS_KEY_ATTR_ETHERTYPE));
+
+	/* Check key attributes. */
+	if (match->key->eth.type == htons(ETH_P_ARP)
+			|| match->key->eth.type == htons(ETH_P_RARP)) {
+		key_expected |= 1 << OVS_KEY_ATTR_ARP;
+		if (match->mask && (match->mask->key.eth.type == htons(0xffff)))
+			mask_allowed |= 1 << OVS_KEY_ATTR_ARP;
+	}
+
+	if (match->key->eth.type == htons(ETH_P_IP)) {
+		key_expected |= 1 << OVS_KEY_ATTR_IPV4;
+		if (match->mask && (match->mask->key.eth.type == htons(0xffff)))
+			mask_allowed |= 1 << OVS_KEY_ATTR_IPV4;
+
+		if (match->key->ip.frag != OVS_FRAG_TYPE_LATER) {
+			if (match->key->ip.proto == IPPROTO_UDP) {
+				key_expected |= 1 << OVS_KEY_ATTR_UDP;
+				if (match->mask && (match->mask->key.ip.proto == 0xff))
+					mask_allowed |= 1 << OVS_KEY_ATTR_UDP;
+			}
+
+			if (match->key->ip.proto == IPPROTO_SCTP) {
+				key_expected |= 1 << OVS_KEY_ATTR_SCTP;
+				if (match->mask && (match->mask->key.ip.proto == 0xff))
+					mask_allowed |= 1 << OVS_KEY_ATTR_SCTP;
+			}
+
+			if (match->key->ip.proto == IPPROTO_TCP) {
+				key_expected |= 1 << OVS_KEY_ATTR_TCP;
+				if (match->mask && (match->mask->key.ip.proto == 0xff))
+					mask_allowed |= 1 << OVS_KEY_ATTR_TCP;
+			}
+
+			if (match->key->ip.proto == IPPROTO_ICMP) {
+				key_expected |= 1 << OVS_KEY_ATTR_ICMP;
+				if (match->mask && (match->mask->key.ip.proto == 0xff))
+					mask_allowed |= 1 << OVS_KEY_ATTR_ICMP;
+			}
+		}
+	}
+
+	if (match->key->eth.type == htons(ETH_P_IPV6)) {
+		key_expected |= 1 << OVS_KEY_ATTR_IPV6;
+		if (match->mask && (match->mask->key.eth.type == htons(0xffff)))
+			mask_allowed |= 1 << OVS_KEY_ATTR_IPV6;
+
+		if (match->key->ip.frag != OVS_FRAG_TYPE_LATER) {
+			if (match->key->ip.proto == IPPROTO_UDP) {
+				key_expected |= 1 << OVS_KEY_ATTR_UDP;
+				if (match->mask && (match->mask->key.ip.proto == 0xff))
+					mask_allowed |= 1 << OVS_KEY_ATTR_UDP;
+			}
+
+			if (match->key->ip.proto == IPPROTO_SCTP) {
+				key_expected |= 1 << OVS_KEY_ATTR_SCTP;
+				if (match->mask && (match->mask->key.ip.proto == 0xff))
+					mask_allowed |= 1 << OVS_KEY_ATTR_SCTP;
+			}
+
+			if (match->key->ip.proto == IPPROTO_TCP) {
+				key_expected |= 1 << OVS_KEY_ATTR_TCP;
+				if (match->mask && (match->mask->key.ip.proto == 0xff))
+					mask_allowed |= 1 << OVS_KEY_ATTR_TCP;
+			}
+
+			if (match->key->ip.proto == IPPROTO_ICMPV6) {
+				key_expected |= 1 << OVS_KEY_ATTR_ICMPV6;
+				if (match->mask && (match->mask->key.ip.proto == 0xff))
+					mask_allowed |= 1 << OVS_KEY_ATTR_ICMPV6;
+
+				if (match->key->ipv6.tp.src ==
+						htons(NDISC_NEIGHBOUR_SOLICITATION) ||
+				    match->key->ipv6.tp.src == htons(NDISC_NEIGHBOUR_ADVERTISEMENT)) {
+					key_expected |= 1 << OVS_KEY_ATTR_ND;
+					if (match->mask && (match->mask->key.ipv6.tp.src == htons(0xffff)))
+						mask_allowed |= 1 << OVS_KEY_ATTR_ND;
+				}
+			}
+		}
+	}
+
+	if ((key_attrs & key_expected) != key_expected) {
+		/* Key attributes check failed. */
+		OVS_NLERR("Missing expected key attributes (key_attrs=%llx, expected=%llx).\n",
+				key_attrs, key_expected);
+		return false;
+	}
+
+	if ((mask_attrs & mask_allowed) != mask_attrs) {
+		/* Mask attributes check failed. */
+		OVS_NLERR("Contain more than allowed mask fields (mask_attrs=%llx, mask_allowed=%llx).\n",
+				mask_attrs, mask_allowed);
+		return false;
+	}
+
+	return true;
 }
 
 static int check_header(struct sk_buff *skb, int len)
@@ -147,6 +311,19 @@ static bool icmphdr_ok(struct sk_buff *skb)
 				  sizeof(struct icmphdr));
 }
 
+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;
+}
+
 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
 {
 	unsigned int nh_ofs = skb_network_offset(skb);
@@ -195,6 +372,311 @@ static bool icmp6hdr_ok(struct sk_buff *skb)
 				  sizeof(struct icmp6hdr));
 }
 
+void ovs_flow_key_mask(struct sw_flow_key *dst, const struct sw_flow_key *src,
+		       const struct sw_flow_mask *mask)
+{
+	const long *m = (long *)((u8 *)&mask->key + mask->range.start);
+	const long *s = (long *)((u8 *)src + mask->range.start);
+	long *d = (long *)((u8 *)dst + mask->range.start);
+	int i;
+
+	/* The memory outside of the 'mask->range' are not set since
+	 * further operations on 'dst' only uses contents within
+	 * 'mask->range'.
+	 */
+	for (i = 0; i < range_n_bytes(&mask->range); i += sizeof(long))
+		*d++ = *s++ & *m++;
+}
+
+#define TCP_FLAGS_OFFSET 13
+#define TCP_FLAG_MASK 0x3f
+
+void ovs_flow_used(struct sw_flow *flow, struct sk_buff *skb)
+{
+	u8 tcp_flags = 0;
+
+	if ((flow->key.eth.type == htons(ETH_P_IP) ||
+	     flow->key.eth.type == htons(ETH_P_IPV6)) &&
+	    flow->key.ip.proto == IPPROTO_TCP &&
+	    likely(skb->len >= skb_transport_offset(skb) + sizeof(struct tcphdr))) {
+		u8 *tcp = (u8 *)tcp_hdr(skb);
+		tcp_flags = *(tcp + TCP_FLAGS_OFFSET) & TCP_FLAG_MASK;
+	}
+
+	spin_lock(&flow->lock);
+	flow->used = jiffies;
+	flow->packet_count++;
+	flow->byte_count += skb->len;
+	flow->tcp_flags |= tcp_flags;
+	spin_unlock(&flow->lock);
+}
+
+struct sw_flow_actions *ovs_flow_actions_alloc(int size)
+{
+	struct sw_flow_actions *sfa;
+
+	if (size > MAX_ACTIONS_BUFSIZE)
+		return ERR_PTR(-EINVAL);
+
+	sfa = kmalloc(sizeof(*sfa) + size, GFP_KERNEL);
+	if (!sfa)
+		return ERR_PTR(-ENOMEM);
+
+	sfa->actions_len = 0;
+	return sfa;
+}
+
+struct sw_flow *ovs_flow_alloc(void)
+{
+	struct sw_flow *flow;
+
+	flow = kmem_cache_alloc(flow_cache, GFP_KERNEL);
+	if (!flow)
+		return ERR_PTR(-ENOMEM);
+
+	spin_lock_init(&flow->lock);
+	flow->sf_acts = NULL;
+	flow->mask = NULL;
+
+	return flow;
+}
+
+static struct hlist_head *find_bucket(struct flow_table *table, u32 hash)
+{
+	hash = jhash_1word(hash, table->hash_seed);
+	return flex_array_get(table->buckets,
+				(hash & (table->n_buckets - 1)));
+}
+
+static struct flex_array *alloc_buckets(unsigned int n_buckets)
+{
+	struct flex_array *buckets;
+	int i, err;
+
+	buckets = flex_array_alloc(sizeof(struct hlist_head),
+				   n_buckets, GFP_KERNEL);
+	if (!buckets)
+		return NULL;
+
+	err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL);
+	if (err) {
+		flex_array_free(buckets);
+		return NULL;
+	}
+
+	for (i = 0; i < n_buckets; i++)
+		INIT_HLIST_HEAD((struct hlist_head *)
+					flex_array_get(buckets, i));
+
+	return buckets;
+}
+
+static void free_buckets(struct flex_array *buckets)
+{
+	flex_array_free(buckets);
+}
+
+static struct flow_table *__flow_tbl_alloc(int new_size)
+{
+	struct flow_table *table = kmalloc(sizeof(*table), GFP_KERNEL);
+
+	if (!table)
+		return NULL;
+
+	table->buckets = alloc_buckets(new_size);
+
+	if (!table->buckets) {
+		kfree(table);
+		return NULL;
+	}
+	table->n_buckets = new_size;
+	table->count = 0;
+	table->node_ver = 0;
+	table->keep_flows = false;
+	get_random_bytes(&table->hash_seed, sizeof(u32));
+	table->mask_list = NULL;
+
+	return table;
+}
+
+static void __flow_tbl_destroy(struct flow_table *table)
+{
+	int i;
+
+	if (table->keep_flows)
+		goto skip_flows;
+
+	for (i = 0; i < table->n_buckets; i++) {
+		struct sw_flow *flow;
+		struct hlist_head *head = flex_array_get(table->buckets, i);
+		struct hlist_node *n;
+		int ver = table->node_ver;
+
+		hlist_for_each_entry_safe(flow, n, head, hash_node[ver]) {
+			hlist_del(&flow->hash_node[ver]);
+			ovs_flow_free(flow, false);
+		}
+	}
+
+	BUG_ON(!list_empty(table->mask_list));
+	kfree(table->mask_list);
+
+skip_flows:
+	free_buckets(table->buckets);
+	kfree(table);
+}
+
+struct flow_table *ovs_flow_tbl_alloc(int new_size)
+{
+	struct flow_table *table = __flow_tbl_alloc(new_size);
+
+	if (!table)
+		return NULL;
+
+	table->mask_list = kmalloc(sizeof(struct list_head), GFP_KERNEL);
+	if (!table->mask_list) {
+		table->keep_flows = true;
+		__flow_tbl_destroy(table);
+		return NULL;
+	}
+	INIT_LIST_HEAD(table->mask_list);
+
+	return table;
+}
+
+static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
+{
+	struct flow_table *table = container_of(rcu, struct flow_table, rcu);
+
+	__flow_tbl_destroy(table);
+}
+
+void ovs_flow_tbl_destroy(struct flow_table *table, bool deferred)
+{
+	if (!table)
+		return;
+
+	if (deferred)
+		call_rcu(&table->rcu, flow_tbl_destroy_rcu_cb);
+	else
+		__flow_tbl_destroy(table);
+}
+
+struct sw_flow *ovs_flow_dump_next(struct flow_table *table, u32 *bucket, u32 *last)
+{
+	struct sw_flow *flow;
+	struct hlist_head *head;
+	int ver;
+	int i;
+
+	ver = table->node_ver;
+	while (*bucket < table->n_buckets) {
+		i = 0;
+		head = flex_array_get(table->buckets, *bucket);
+		hlist_for_each_entry_rcu(flow, head, hash_node[ver]) {
+			if (i < *last) {
+				i++;
+				continue;
+			}
+			*last = i + 1;
+			return flow;
+		}
+		(*bucket)++;
+		*last = 0;
+	}
+
+	return NULL;
+}
+
+static void __tbl_insert(struct flow_table *table, struct sw_flow *flow)
+{
+	struct hlist_head *head;
+
+	head = find_bucket(table, flow->hash);
+	hlist_add_head_rcu(&flow->hash_node[table->node_ver], head);
+
+	table->count++;
+}
+
+static void flow_table_copy_flows(struct flow_table *old, struct flow_table *new)
+{
+	int old_ver;
+	int i;
+
+	old_ver = old->node_ver;
+	new->node_ver = !old_ver;
+
+	/* Insert in new table. */
+	for (i = 0; i < old->n_buckets; i++) {
+		struct sw_flow *flow;
+		struct hlist_head *head;
+
+		head = flex_array_get(old->buckets, i);
+
+		hlist_for_each_entry(flow, head, hash_node[old_ver])
+			__tbl_insert(new, flow);
+	}
+
+	new->mask_list = old->mask_list;
+	old->keep_flows = true;
+}
+
+static struct flow_table *__flow_tbl_rehash(struct flow_table *table, int n_buckets)
+{
+	struct flow_table *new_table;
+
+	new_table = __flow_tbl_alloc(n_buckets);
+	if (!new_table)
+		return ERR_PTR(-ENOMEM);
+
+	flow_table_copy_flows(table, new_table);
+
+	return new_table;
+}
+
+struct flow_table *ovs_flow_tbl_rehash(struct flow_table *table)
+{
+	return __flow_tbl_rehash(table, table->n_buckets);
+}
+
+struct flow_table *ovs_flow_tbl_expand(struct flow_table *table)
+{
+	return __flow_tbl_rehash(table, table->n_buckets * 2);
+}
+
+static void __flow_free(struct sw_flow *flow)
+{
+	kfree((struct sf_flow_acts __force *)flow->sf_acts);
+	kmem_cache_free(flow_cache, flow);
+}
+
+static void rcu_free_flow_callback(struct rcu_head *rcu)
+{
+	struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
+
+	__flow_free(flow);
+}
+
+void ovs_flow_free(struct sw_flow *flow, bool deferred)
+{
+	if (!flow)
+		return;
+
+	ovs_sw_flow_mask_del_ref(flow->mask, deferred);
+
+	if (deferred)
+		call_rcu(&flow->rcu, rcu_free_flow_callback);
+	else
+		__flow_free(flow);
+}
+
+/* Schedules 'sf_acts' to be freed after the next RCU grace period.
+ * The caller must hold rcu_read_lock for this to be sensible. */
+void ovs_flow_deferred_free_acts(struct sw_flow_actions *sf_acts)
+{
+	kfree_rcu(sf_acts, rcu);
+}
+
 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 {
 	struct qtag_prefix {
@@ -428,7 +910,6 @@ int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key)
 				struct tcphdr *tcp = tcp_hdr(skb);
 				key->ipv4.tp.src = tcp->source;
 				key->ipv4.tp.dst = tcp->dest;
-				key->ipv4.tp.flags = TCP_FLAGS_BE16(tcp);
 			}
 		} else if (key->ip.proto == IPPROTO_UDP) {
 			if (udphdr_ok(skb)) {
@@ -497,7 +978,6 @@ int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key)
 				struct tcphdr *tcp = tcp_hdr(skb);
 				key->ipv6.tp.src = tcp->source;
 				key->ipv6.tp.dst = tcp->dest;
-				key->ipv6.tp.flags = TCP_FLAGS_BE16(tcp);
 			}
 		} else if (key->ip.proto == NEXTHDR_UDP) {
 			if (udphdr_ok(skb)) {
@@ -522,3 +1002,1080 @@ int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key)
 
 	return 0;
 }
+
+static u32 ovs_flow_hash(const struct sw_flow_key *key, int key_start,
+			 int key_end)
+{
+	u32 *hash_key = (u32 *)((u8 *)key + key_start);
+	int hash_u32s = (key_end - key_start) >> 2;
+
+	/* Make sure number of hash bytes are multiple of u32. */
+	BUILD_BUG_ON(sizeof(long) % sizeof(u32));
+
+	return jhash2(hash_key, hash_u32s, 0);
+}
+
+static int flow_key_start(const struct sw_flow_key *key)
+{
+	if (key->tun_key.ipv4_dst)
+		return 0;
+	else
+		return rounddown(offsetof(struct sw_flow_key, phy),
+					  sizeof(long));
+}
+
+static bool __cmp_key(const struct sw_flow_key *key1,
+		const struct sw_flow_key *key2,  int key_start, int key_end)
+{
+	const long *cp1 = (long *)((u8 *)key1 + key_start);
+	const long *cp2 = (long *)((u8 *)key2 + key_start);
+	long diffs = 0;
+	int i;
+
+	for (i = key_start; i < key_end;  i += sizeof(long))
+		diffs |= *cp1++ ^ *cp2++;
+
+	return diffs == 0;
+}
+
+static bool __flow_cmp_masked_key(const struct sw_flow *flow,
+		const struct sw_flow_key *key, int key_start, int key_end)
+{
+	return __cmp_key(&flow->key, key, key_start, key_end);
+}
+
+static bool __flow_cmp_unmasked_key(const struct sw_flow *flow,
+		  const struct sw_flow_key *key, int key_start, int key_end)
+{
+	return __cmp_key(&flow->unmasked_key, key, key_start, key_end);
+}
+
+bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
+		const struct sw_flow_key *key, int key_end)
+{
+	int key_start;
+	key_start = flow_key_start(key);
+
+	return __flow_cmp_unmasked_key(flow, key, key_start, key_end);
+
+}
+
+struct sw_flow *ovs_flow_lookup_unmasked_key(struct flow_table *table,
+				       struct sw_flow_match *match)
+{
+	struct sw_flow_key *unmasked = match->key;
+	int key_end = match->range.end;
+	struct sw_flow *flow;
+
+	flow = ovs_flow_lookup(table, unmasked);
+	if (flow && (!ovs_flow_cmp_unmasked_key(flow, unmasked, key_end)))
+		flow = NULL;
+
+	return flow;
+}
+
+static struct sw_flow *ovs_masked_flow_lookup(struct flow_table *table,
+				    const struct sw_flow_key *unmasked,
+				    struct sw_flow_mask *mask)
+{
+	struct sw_flow *flow;
+	struct hlist_head *head;
+	int key_start = mask->range.start;
+	int key_end = mask->range.end;
+	u32 hash;
+	struct sw_flow_key masked_key;
+
+	ovs_flow_key_mask(&masked_key, unmasked, mask);
+	hash = ovs_flow_hash(&masked_key, key_start, key_end);
+	head = find_bucket(table, hash);
+	hlist_for_each_entry_rcu(flow, head, hash_node[table->node_ver]) {
+		if (flow->mask == mask &&
+		    __flow_cmp_masked_key(flow, &masked_key,
+					  key_start, key_end))
+			return flow;
+	}
+	return NULL;
+}
+
+struct sw_flow *ovs_flow_lookup(struct flow_table *tbl,
+				const struct sw_flow_key *key)
+{
+	struct sw_flow *flow = NULL;
+	struct sw_flow_mask *mask;
+
+	list_for_each_entry_rcu(mask, tbl->mask_list, list) {
+		flow = ovs_masked_flow_lookup(tbl, key, mask);
+		if (flow)  /* Found */
+			break;
+	}
+
+	return flow;
+}
+
+
+void ovs_flow_insert(struct flow_table *table, struct sw_flow *flow)
+{
+	flow->hash = ovs_flow_hash(&flow->key, flow->mask->range.start,
+			flow->mask->range.end);
+	__tbl_insert(table, flow);
+}
+
+void ovs_flow_remove(struct flow_table *table, struct sw_flow *flow)
+{
+	BUG_ON(table->count == 0);
+	hlist_del_rcu(&flow->hash_node[table->node_ver]);
+	table->count--;
+}
+
+/* The size of the argument for each %OVS_KEY_ATTR_* Netlink attribute.  */
+const int ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
+	[OVS_KEY_ATTR_ENCAP] = -1,
+	[OVS_KEY_ATTR_PRIORITY] = sizeof(u32),
+	[OVS_KEY_ATTR_IN_PORT] = sizeof(u32),
+	[OVS_KEY_ATTR_SKB_MARK] = sizeof(u32),
+	[OVS_KEY_ATTR_ETHERNET] = sizeof(struct ovs_key_ethernet),
+	[OVS_KEY_ATTR_VLAN] = sizeof(__be16),
+	[OVS_KEY_ATTR_ETHERTYPE] = sizeof(__be16),
+	[OVS_KEY_ATTR_IPV4] = sizeof(struct ovs_key_ipv4),
+	[OVS_KEY_ATTR_IPV6] = sizeof(struct ovs_key_ipv6),
+	[OVS_KEY_ATTR_TCP] = sizeof(struct ovs_key_tcp),
+	[OVS_KEY_ATTR_UDP] = sizeof(struct ovs_key_udp),
+	[OVS_KEY_ATTR_SCTP] = sizeof(struct ovs_key_sctp),
+	[OVS_KEY_ATTR_ICMP] = sizeof(struct ovs_key_icmp),
+	[OVS_KEY_ATTR_ICMPV6] = sizeof(struct ovs_key_icmpv6),
+	[OVS_KEY_ATTR_ARP] = sizeof(struct ovs_key_arp),
+	[OVS_KEY_ATTR_ND] = sizeof(struct ovs_key_nd),
+	[OVS_KEY_ATTR_TUNNEL] = -1,
+};
+
+static bool is_all_zero(const u8 *fp, size_t size)
+{
+	int i;
+
+	if (!fp)
+		return false;
+
+	for (i = 0; i < size; i++)
+		if (fp[i])
+			return false;
+
+	return true;
+}
+
+static int __parse_flow_nlattrs(const struct nlattr *attr,
+			      const struct nlattr *a[],
+			      u64 *attrsp, bool nz)
+{
+	const struct nlattr *nla;
+	u32 attrs;
+	int rem;
+
+	attrs = *attrsp;
+	nla_for_each_nested(nla, attr, rem) {
+		u16 type = nla_type(nla);
+		int expected_len;
+
+		if (type > OVS_KEY_ATTR_MAX) {
+			OVS_NLERR("Unknown key attribute (type=%d, max=%d).\n",
+				  type, OVS_KEY_ATTR_MAX);
+			return -EINVAL;
+		}
+
+		if (attrs & (1 << type)) {
+			OVS_NLERR("Duplicate key attribute (type %d).\n", type);
+			return -EINVAL;
+		}
+
+		expected_len = ovs_key_lens[type];
+		if (nla_len(nla) != expected_len && expected_len != -1) {
+			OVS_NLERR("Key attribute has unexpected length (type=%d"
+				  ", length=%d, expected=%d).\n", type,
+				  nla_len(nla), expected_len);
+			return -EINVAL;
+		}
+
+		if (!nz || !is_all_zero(nla_data(nla), expected_len)) {
+			attrs |= 1 << type;
+			a[type] = nla;
+		}
+	}
+	if (rem) {
+		OVS_NLERR("Message has %d unknown bytes.\n", rem);
+		return -EINVAL;
+	}
+
+	*attrsp = attrs;
+	return 0;
+}
+
+static int parse_flow_mask_nlattrs(const struct nlattr *attr,
+			      const struct nlattr *a[], u64 *attrsp)
+{
+	return __parse_flow_nlattrs(attr, a, attrsp, true);
+}
+
+static int parse_flow_nlattrs(const struct nlattr *attr,
+			      const struct nlattr *a[], u64 *attrsp)
+{
+	return __parse_flow_nlattrs(attr, a, attrsp, false);
+}
+
+int ovs_ipv4_tun_from_nlattr(const struct nlattr *attr,
+			     struct sw_flow_match *match, bool is_mask)
+{
+	struct nlattr *a;
+	int rem;
+	bool ttl = false;
+	__be16 tun_flags = 0;
+
+	nla_for_each_nested(a, attr, rem) {
+		int type = nla_type(a);
+		static const u32 ovs_tunnel_key_lens[OVS_TUNNEL_KEY_ATTR_MAX + 1] = {
+			[OVS_TUNNEL_KEY_ATTR_ID] = sizeof(u64),
+			[OVS_TUNNEL_KEY_ATTR_IPV4_SRC] = sizeof(u32),
+			[OVS_TUNNEL_KEY_ATTR_IPV4_DST] = sizeof(u32),
+			[OVS_TUNNEL_KEY_ATTR_TOS] = 1,
+			[OVS_TUNNEL_KEY_ATTR_TTL] = 1,
+			[OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT] = 0,
+			[OVS_TUNNEL_KEY_ATTR_CSUM] = 0,
+		};
+
+		if (type > OVS_TUNNEL_KEY_ATTR_MAX) {
+			OVS_NLERR("Unknown IPv4 tunnel attribute (type=%d, max=%d).\n",
+			type, OVS_TUNNEL_KEY_ATTR_MAX);
+			return -EINVAL;
+		}
+
+		if (ovs_tunnel_key_lens[type] != nla_len(a)) {
+			OVS_NLERR("IPv4 tunnel attribute type has unexpected "
+				  " length (type=%d, length=%d, expected=%d).\n",
+				  type, nla_len(a), ovs_tunnel_key_lens[type]);
+			return -EINVAL;
+		}
+
+		switch (type) {
+		case OVS_TUNNEL_KEY_ATTR_ID:
+			SW_FLOW_KEY_PUT(match, tun_key.tun_id,
+					nla_get_be64(a), is_mask);
+			tun_flags |= TUNNEL_KEY;
+			break;
+		case OVS_TUNNEL_KEY_ATTR_IPV4_SRC:
+			SW_FLOW_KEY_PUT(match, tun_key.ipv4_src,
+					nla_get_be32(a), is_mask);
+			break;
+		case OVS_TUNNEL_KEY_ATTR_IPV4_DST:
+			SW_FLOW_KEY_PUT(match, tun_key.ipv4_dst,
+					nla_get_be32(a), is_mask);
+			break;
+		case OVS_TUNNEL_KEY_ATTR_TOS:
+			SW_FLOW_KEY_PUT(match, tun_key.ipv4_tos,
+					nla_get_u8(a), is_mask);
+			break;
+		case OVS_TUNNEL_KEY_ATTR_TTL:
+			SW_FLOW_KEY_PUT(match, tun_key.ipv4_ttl,
+					nla_get_u8(a), is_mask);
+			ttl = true;
+			break;
+		case OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT:
+			tun_flags |= TUNNEL_DONT_FRAGMENT;
+			break;
+		case OVS_TUNNEL_KEY_ATTR_CSUM:
+			tun_flags |= TUNNEL_CSUM;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	SW_FLOW_KEY_PUT(match, tun_key.tun_flags, tun_flags, is_mask);
+
+	if (rem > 0) {
+		OVS_NLERR("IPv4 tunnel attribute has %d unknown bytes.\n", rem);
+		return -EINVAL;
+	}
+
+	if (!is_mask) {
+		if (!match->key->tun_key.ipv4_dst) {
+			OVS_NLERR("IPv4 tunnel destination address is zero.\n");
+			return -EINVAL;
+		}
+
+		if (!ttl) {
+			OVS_NLERR("IPv4 tunnel TTL not specified.\n");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+int ovs_ipv4_tun_to_nlattr(struct sk_buff *skb,
+			   const struct ovs_key_ipv4_tunnel *tun_key,
+			   const struct ovs_key_ipv4_tunnel *output)
+{
+	struct nlattr *nla;
+
+	nla = nla_nest_start(skb, OVS_KEY_ATTR_TUNNEL);
+	if (!nla)
+		return -EMSGSIZE;
+
+	if (output->tun_flags & TUNNEL_KEY &&
+	    nla_put_be64(skb, OVS_TUNNEL_KEY_ATTR_ID, output->tun_id))
+		return -EMSGSIZE;
+	if (output->ipv4_src &&
+		nla_put_be32(skb, OVS_TUNNEL_KEY_ATTR_IPV4_SRC, output->ipv4_src))
+		return -EMSGSIZE;
+	if (output->ipv4_dst &&
+		nla_put_be32(skb, OVS_TUNNEL_KEY_ATTR_IPV4_DST, output->ipv4_dst))
+		return -EMSGSIZE;
+	if (output->ipv4_tos &&
+		nla_put_u8(skb, OVS_TUNNEL_KEY_ATTR_TOS, output->ipv4_tos))
+		return -EMSGSIZE;
+	if (nla_put_u8(skb, OVS_TUNNEL_KEY_ATTR_TTL, output->ipv4_ttl))
+		return -EMSGSIZE;
+	if ((output->tun_flags & TUNNEL_DONT_FRAGMENT) &&
+		nla_put_flag(skb, OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT))
+		return -EMSGSIZE;
+	if ((output->tun_flags & TUNNEL_CSUM) &&
+		nla_put_flag(skb, OVS_TUNNEL_KEY_ATTR_CSUM))
+		return -EMSGSIZE;
+
+	nla_nest_end(skb, nla);
+	return 0;
+}
+
+static int metadata_from_nlattrs(struct sw_flow_match *match,  u64 *attrs,
+		const struct nlattr **a, bool is_mask)
+{
+	if (*attrs & (1 << OVS_KEY_ATTR_PRIORITY)) {
+		SW_FLOW_KEY_PUT(match, phy.priority,
+			  nla_get_u32(a[OVS_KEY_ATTR_PRIORITY]), is_mask);
+		*attrs &= ~(1 << OVS_KEY_ATTR_PRIORITY);
+	}
+
+	if (*attrs & (1 << OVS_KEY_ATTR_IN_PORT)) {
+		u32 in_port = nla_get_u32(a[OVS_KEY_ATTR_IN_PORT]);
+
+		if (is_mask)
+			in_port = 0xffffffff; /* Always exact match in_port. */
+		else if (in_port >= DP_MAX_PORTS)
+			return -EINVAL;
+
+		SW_FLOW_KEY_PUT(match, phy.in_port, in_port, is_mask);
+		*attrs &= ~(1 << OVS_KEY_ATTR_IN_PORT);
+	} else if (!is_mask) {
+		SW_FLOW_KEY_PUT(match, phy.in_port, DP_MAX_PORTS, is_mask);
+	}
+
+	if (*attrs & (1 << OVS_KEY_ATTR_SKB_MARK)) {
+		uint32_t mark = nla_get_u32(a[OVS_KEY_ATTR_SKB_MARK]);
+
+		SW_FLOW_KEY_PUT(match, phy.skb_mark, mark, is_mask);
+		*attrs &= ~(1 << OVS_KEY_ATTR_SKB_MARK);
+	}
+	if (*attrs & (1 << OVS_KEY_ATTR_TUNNEL)) {
+		if (ovs_ipv4_tun_from_nlattr(a[OVS_KEY_ATTR_TUNNEL], match,
+					is_mask))
+			return -EINVAL;
+		*attrs &= ~(1 << OVS_KEY_ATTR_TUNNEL);
+	}
+	return 0;
+}
+
+static int ovs_key_from_nlattrs(struct sw_flow_match *match,  u64 attrs,
+		const struct nlattr **a, bool is_mask)
+{
+	int err;
+	u64 orig_attrs = attrs;
+
+	err = metadata_from_nlattrs(match, &attrs, a, is_mask);
+	if (err)
+		return err;
+
+	if (attrs & (1 << OVS_KEY_ATTR_ETHERNET)) {
+		const struct ovs_key_ethernet *eth_key;
+
+		eth_key = nla_data(a[OVS_KEY_ATTR_ETHERNET]);
+		SW_FLOW_KEY_MEMCPY(match, eth.src,
+				eth_key->eth_src, ETH_ALEN, is_mask);
+		SW_FLOW_KEY_MEMCPY(match, eth.dst,
+				eth_key->eth_dst, ETH_ALEN, is_mask);
+		attrs &= ~(1 << OVS_KEY_ATTR_ETHERNET);
+	}
+
+	if (attrs & (1 << OVS_KEY_ATTR_VLAN)) {
+		__be16 tci;
+
+		tci = nla_get_be16(a[OVS_KEY_ATTR_VLAN]);
+		if (!(tci & htons(VLAN_TAG_PRESENT))) {
+			if (is_mask)
+				OVS_NLERR("VLAN TCI mask does not have exact match for VLAN_TAG_PRESENT bit.\n");
+			else
+				OVS_NLERR("VLAN TCI does not have VLAN_TAG_PRESENT bit set.\n");
+
+			return -EINVAL;
+		}
+
+		SW_FLOW_KEY_PUT(match, eth.tci, tci, is_mask);
+		attrs &= ~(1 << OVS_KEY_ATTR_VLAN);
+	} else if (!is_mask)
+		SW_FLOW_KEY_PUT(match, eth.tci, htons(0xffff), true);
+
+	if (attrs & (1 << OVS_KEY_ATTR_ETHERTYPE)) {
+		__be16 eth_type;
+
+		eth_type = nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]);
+		if (is_mask) {
+			/* Always exact match EtherType. */
+			eth_type = htons(0xffff);
+		} else if (ntohs(eth_type) < ETH_P_802_3_MIN) {
+			OVS_NLERR("EtherType is less than minimum (type=%x, min=%x).\n",
+					ntohs(eth_type), ETH_P_802_3_MIN);
+			return -EINVAL;
+		}
+
+		SW_FLOW_KEY_PUT(match, eth.type, eth_type, is_mask);
+		attrs &= ~(1 << OVS_KEY_ATTR_ETHERTYPE);
+	} else if (!is_mask) {
+		SW_FLOW_KEY_PUT(match, eth.type, htons(ETH_P_802_2), is_mask);
+	}
+
+	if (attrs & (1 << OVS_KEY_ATTR_IPV4)) {
+		const struct ovs_key_ipv4 *ipv4_key;
+
+		ipv4_key = nla_data(a[OVS_KEY_ATTR_IPV4]);
+		if (!is_mask && ipv4_key->ipv4_frag > OVS_FRAG_TYPE_MAX) {
+			OVS_NLERR("Unknown IPv4 fragment type (value=%d, max=%d).\n",
+				ipv4_key->ipv4_frag, OVS_FRAG_TYPE_MAX);
+			return -EINVAL;
+		}
+		SW_FLOW_KEY_PUT(match, ip.proto,
+				ipv4_key->ipv4_proto, is_mask);
+		SW_FLOW_KEY_PUT(match, ip.tos,
+				ipv4_key->ipv4_tos, is_mask);
+		SW_FLOW_KEY_PUT(match, ip.ttl,
+				ipv4_key->ipv4_ttl, is_mask);
+		SW_FLOW_KEY_PUT(match, ip.frag,
+				ipv4_key->ipv4_frag, is_mask);
+		SW_FLOW_KEY_PUT(match, ipv4.addr.src,
+				ipv4_key->ipv4_src, is_mask);
+		SW_FLOW_KEY_PUT(match, ipv4.addr.dst,
+				ipv4_key->ipv4_dst, is_mask);
+		attrs &= ~(1 << OVS_KEY_ATTR_IPV4);
+	}
+
+	if (attrs & (1 << OVS_KEY_ATTR_IPV6)) {
+		const struct ovs_key_ipv6 *ipv6_key;
+
+		ipv6_key = nla_data(a[OVS_KEY_ATTR_IPV6]);
+		if (!is_mask && ipv6_key->ipv6_frag > OVS_FRAG_TYPE_MAX) {
+			OVS_NLERR("Unknown IPv6 fragment type (value=%d, max=%d).\n",
+				ipv6_key->ipv6_frag, OVS_FRAG_TYPE_MAX);
+			return -EINVAL;
+		}
+		SW_FLOW_KEY_PUT(match, ipv6.label,
+				ipv6_key->ipv6_label, is_mask);
+		SW_FLOW_KEY_PUT(match, ip.proto,
+				ipv6_key->ipv6_proto, is_mask);
+		SW_FLOW_KEY_PUT(match, ip.tos,
+				ipv6_key->ipv6_tclass, is_mask);
+		SW_FLOW_KEY_PUT(match, ip.ttl,
+				ipv6_key->ipv6_hlimit, is_mask);
+		SW_FLOW_KEY_PUT(match, ip.frag,
+				ipv6_key->ipv6_frag, is_mask);
+		SW_FLOW_KEY_MEMCPY(match, ipv6.addr.src,
+				ipv6_key->ipv6_src,
+				sizeof(match->key->ipv6.addr.src),
+				is_mask);
+		SW_FLOW_KEY_MEMCPY(match, ipv6.addr.dst,
+				ipv6_key->ipv6_dst,
+				sizeof(match->key->ipv6.addr.dst),
+				is_mask);
+
+		attrs &= ~(1 << OVS_KEY_ATTR_IPV6);
+	}
+
+	if (attrs & (1 << OVS_KEY_ATTR_ARP)) {
+		const struct ovs_key_arp *arp_key;
+
+		arp_key = nla_data(a[OVS_KEY_ATTR_ARP]);
+		if (!is_mask && (arp_key->arp_op & htons(0xff00))) {
+			OVS_NLERR("Unknown ARP opcode (opcode=%d).\n",
+				  arp_key->arp_op);
+			return -EINVAL;
+		}
+
+		SW_FLOW_KEY_PUT(match, ipv4.addr.src,
+				arp_key->arp_sip, is_mask);
+		SW_FLOW_KEY_PUT(match, ipv4.addr.dst,
+			arp_key->arp_tip, is_mask);
+		SW_FLOW_KEY_PUT(match, ip.proto,
+				ntohs(arp_key->arp_op), is_mask);
+		SW_FLOW_KEY_MEMCPY(match, ipv4.arp.sha,
+				arp_key->arp_sha, ETH_ALEN, is_mask);
+		SW_FLOW_KEY_MEMCPY(match, ipv4.arp.tha,
+				arp_key->arp_tha, ETH_ALEN, is_mask);
+
+		attrs &= ~(1 << OVS_KEY_ATTR_ARP);
+	}
+
+	if (attrs & (1 << OVS_KEY_ATTR_TCP)) {
+		const struct ovs_key_tcp *tcp_key;
+
+		tcp_key = nla_data(a[OVS_KEY_ATTR_TCP]);
+		if (orig_attrs & (1 << OVS_KEY_ATTR_IPV4)) {
+			SW_FLOW_KEY_PUT(match, ipv4.tp.src,
+					tcp_key->tcp_src, is_mask);
+			SW_FLOW_KEY_PUT(match, ipv4.tp.dst,
+					tcp_key->tcp_dst, is_mask);
+		} else {
+			SW_FLOW_KEY_PUT(match, ipv6.tp.src,
+					tcp_key->tcp_src, is_mask);
+			SW_FLOW_KEY_PUT(match, ipv6.tp.dst,
+					tcp_key->tcp_dst, is_mask);
+		}
+		attrs &= ~(1 << OVS_KEY_ATTR_TCP);
+	}
+
+	if (attrs & (1 << OVS_KEY_ATTR_UDP)) {
+		const struct ovs_key_udp *udp_key;
+
+		udp_key = nla_data(a[OVS_KEY_ATTR_UDP]);
+		if (orig_attrs & (1 << OVS_KEY_ATTR_IPV4)) {
+			SW_FLOW_KEY_PUT(match, ipv4.tp.src,
+					udp_key->udp_src, is_mask);
+			SW_FLOW_KEY_PUT(match, ipv4.tp.dst,
+					udp_key->udp_dst, is_mask);
+		} else {
+			SW_FLOW_KEY_PUT(match, ipv6.tp.src,
+					udp_key->udp_src, is_mask);
+			SW_FLOW_KEY_PUT(match, ipv6.tp.dst,
+					udp_key->udp_dst, is_mask);
+		}
+		attrs &= ~(1 << OVS_KEY_ATTR_UDP);
+	}
+
+	if (attrs & (1 << OVS_KEY_ATTR_SCTP)) {
+		const struct ovs_key_sctp *sctp_key;
+
+		sctp_key = nla_data(a[OVS_KEY_ATTR_SCTP]);
+		if (orig_attrs & (1 << OVS_KEY_ATTR_IPV4)) {
+			SW_FLOW_KEY_PUT(match, ipv4.tp.src,
+					sctp_key->sctp_src, is_mask);
+			SW_FLOW_KEY_PUT(match, ipv4.tp.dst,
+					sctp_key->sctp_dst, is_mask);
+		} else {
+			SW_FLOW_KEY_PUT(match, ipv6.tp.src,
+					sctp_key->sctp_src, is_mask);
+			SW_FLOW_KEY_PUT(match, ipv6.tp.dst,
+					sctp_key->sctp_dst, is_mask);
+		}
+		attrs &= ~(1 << OVS_KEY_ATTR_SCTP);
+	}
+
+	if (attrs & (1 << OVS_KEY_ATTR_ICMP)) {
+		const struct ovs_key_icmp *icmp_key;
+
+		icmp_key = nla_data(a[OVS_KEY_ATTR_ICMP]);
+		SW_FLOW_KEY_PUT(match, ipv4.tp.src,
+				htons(icmp_key->icmp_type), is_mask);
+		SW_FLOW_KEY_PUT(match, ipv4.tp.dst,
+				htons(icmp_key->icmp_code), is_mask);
+		attrs &= ~(1 << OVS_KEY_ATTR_ICMP);
+	}
+
+	if (attrs & (1 << OVS_KEY_ATTR_ICMPV6)) {
+		const struct ovs_key_icmpv6 *icmpv6_key;
+
+		icmpv6_key = nla_data(a[OVS_KEY_ATTR_ICMPV6]);
+		SW_FLOW_KEY_PUT(match, ipv6.tp.src,
+				htons(icmpv6_key->icmpv6_type), is_mask);
+		SW_FLOW_KEY_PUT(match, ipv6.tp.dst,
+				htons(icmpv6_key->icmpv6_code), is_mask);
+		attrs &= ~(1 << OVS_KEY_ATTR_ICMPV6);
+	}
+
+	if (attrs & (1 << OVS_KEY_ATTR_ND)) {
+		const struct ovs_key_nd *nd_key;
+
+		nd_key = nla_data(a[OVS_KEY_ATTR_ND]);
+		SW_FLOW_KEY_MEMCPY(match, ipv6.nd.target,
+			nd_key->nd_target,
+			sizeof(match->key->ipv6.nd.target),
+			is_mask);
+		SW_FLOW_KEY_MEMCPY(match, ipv6.nd.sll,
+			nd_key->nd_sll, ETH_ALEN, is_mask);
+		SW_FLOW_KEY_MEMCPY(match, ipv6.nd.tll,
+				nd_key->nd_tll, ETH_ALEN, is_mask);
+		attrs &= ~(1 << OVS_KEY_ATTR_ND);
+	}
+
+	if (attrs != 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
+ * ovs_match_from_nlattrs - parses Netlink attributes into a flow key and
+ * mask. In case the 'mask' is NULL, the flow is treated as exact match
+ * flow. Otherwise, it is treated as a wildcarded flow, except the mask
+ * does not include any don't care bit.
+ * @match: receives the extracted flow match information.
+ * @key: Netlink attribute holding nested %OVS_KEY_ATTR_* Netlink attribute
+ * sequence. The fields should of the packet that triggered the creation
+ * of this flow.
+ * @mask: Optional. Netlink attribute holding nested %OVS_KEY_ATTR_* Netlink
+ * attribute specifies the mask field of the wildcarded flow.
+ */
+int ovs_match_from_nlattrs(struct sw_flow_match *match,
+			   const struct nlattr *key,
+			   const struct nlattr *mask)
+{
+	const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
+	const struct nlattr *encap;
+	u64 key_attrs = 0;
+	u64 mask_attrs = 0;
+	bool encap_valid = false;
+	int err;
+
+	err = parse_flow_nlattrs(key, a, &key_attrs);
+	if (err)
+		return err;
+
+	if ((key_attrs & (1 << OVS_KEY_ATTR_ETHERNET)) &&
+	    (key_attrs & (1 << OVS_KEY_ATTR_ETHERTYPE)) &&
+	    (nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]) == htons(ETH_P_8021Q))) {
+		__be16 tci;
+
+		if (!((key_attrs & (1 << OVS_KEY_ATTR_VLAN)) &&
+		      (key_attrs & (1 << OVS_KEY_ATTR_ENCAP)))) {
+			OVS_NLERR("Invalid Vlan frame.\n");
+			return -EINVAL;
+		}
+
+		key_attrs &= ~(1 << OVS_KEY_ATTR_ETHERTYPE);
+		tci = nla_get_be16(a[OVS_KEY_ATTR_VLAN]);
+		encap = a[OVS_KEY_ATTR_ENCAP];
+		key_attrs &= ~(1 << OVS_KEY_ATTR_ENCAP);
+		encap_valid = true;
+
+		if (tci & htons(VLAN_TAG_PRESENT)) {
+			err = parse_flow_nlattrs(encap, a, &key_attrs);
+			if (err)
+				return err;
+		} else if (!tci) {
+			/* Corner case for truncated 802.1Q header. */
+			if (nla_len(encap)) {
+				OVS_NLERR("Truncated 802.1Q header has non-zero encap attribute.\n");
+				return -EINVAL;
+			}
+		} else {
+			OVS_NLERR("Encap attribute is set for a non-VLAN frame.\n");
+			return  -EINVAL;
+		}
+	}
+
+	err = ovs_key_from_nlattrs(match, key_attrs, a, false);
+	if (err)
+		return err;
+
+	if (mask) {
+		err = parse_flow_mask_nlattrs(mask, a, &mask_attrs);
+		if (err)
+			return err;
+
+		if (mask_attrs & 1ULL << OVS_KEY_ATTR_ENCAP)  {
+			__be16 eth_type = 0;
+			__be16 tci = 0;
+
+			if (!encap_valid) {
+				OVS_NLERR("Encap mask attribute is set for non-VLAN frame.\n");
+				return  -EINVAL;
+			}
+
+			mask_attrs &= ~(1 << OVS_KEY_ATTR_ENCAP);
+			if (a[OVS_KEY_ATTR_ETHERTYPE])
+				eth_type = nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]);
+
+			if (eth_type == htons(0xffff)) {
+				mask_attrs &= ~(1 << OVS_KEY_ATTR_ETHERTYPE);
+				encap = a[OVS_KEY_ATTR_ENCAP];
+				err = parse_flow_mask_nlattrs(encap, a, &mask_attrs);
+			} else {
+				OVS_NLERR("VLAN frames must have an exact match on the TPID (mask=%x).\n",
+						ntohs(eth_type));
+				return -EINVAL;
+			}
+
+			if (a[OVS_KEY_ATTR_VLAN])
+				tci = nla_get_be16(a[OVS_KEY_ATTR_VLAN]);
+
+			if (!(tci & htons(VLAN_TAG_PRESENT))) {
+				OVS_NLERR("VLAN tag present bit must have an exact match (tci_mask=%x).\n", ntohs(tci));
+				return -EINVAL;
+			}
+		}
+
+		err = ovs_key_from_nlattrs(match, mask_attrs, a, true);
+		if (err)
+			return err;
+	} else {
+		/* Populate exact match flow's key mask. */
+		if (match->mask)
+			ovs_sw_flow_mask_set(match->mask, &match->range, 0xff);
+	}
+
+	if (!ovs_match_validate(match, key_attrs, mask_attrs))
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
+ * ovs_flow_metadata_from_nlattrs - parses Netlink attributes into a flow key.
+ * @flow: Receives extracted in_port, priority, tun_key and skb_mark.
+ * @attr: Netlink attribute holding nested %OVS_KEY_ATTR_* Netlink attribute
+ * sequence.
+ *
+ * This parses a series of Netlink attributes that form a flow key, which must
+ * take the same form accepted by flow_from_nlattrs(), but only enough of it to
+ * get the metadata, that is, the parts of the flow key that cannot be
+ * extracted from the packet itself.
+ */
+
+int ovs_flow_metadata_from_nlattrs(struct sw_flow *flow,
+		const struct nlattr *attr)
+{
+	struct ovs_key_ipv4_tunnel *tun_key = &flow->key.tun_key;
+	const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
+	u64 attrs = 0;
+	int err;
+	struct sw_flow_match match;
+
+	flow->key.phy.in_port = DP_MAX_PORTS;
+	flow->key.phy.priority = 0;
+	flow->key.phy.skb_mark = 0;
+	memset(tun_key, 0, sizeof(flow->key.tun_key));
+
+	err = parse_flow_nlattrs(attr, a, &attrs);
+	if (err)
+		return -EINVAL;
+
+	memset(&match, 0, sizeof(match));
+	match.key = &flow->key;
+
+	err = metadata_from_nlattrs(&match, &attrs, a, false);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+int ovs_flow_to_nlattrs(const struct sw_flow_key *swkey,
+		const struct sw_flow_key *output, struct sk_buff *skb)
+{
+	struct ovs_key_ethernet *eth_key;
+	struct nlattr *nla, *encap;
+	bool is_mask = (swkey != output);
+
+	if (nla_put_u32(skb, OVS_KEY_ATTR_PRIORITY, output->phy.priority))
+		goto nla_put_failure;
+
+	if ((swkey->tun_key.ipv4_dst || is_mask) &&
+	    ovs_ipv4_tun_to_nlattr(skb, &swkey->tun_key, &output->tun_key))
+		goto nla_put_failure;
+
+	if (swkey->phy.in_port == DP_MAX_PORTS) {
+		if (is_mask && (output->phy.in_port == 0xffff))
+			if (nla_put_u32(skb, OVS_KEY_ATTR_IN_PORT, 0xffffffff))
+				goto nla_put_failure;
+	} else {
+		u16 upper_u16;
+		upper_u16 = !is_mask ? 0 : 0xffff;
+
+		if (nla_put_u32(skb, OVS_KEY_ATTR_IN_PORT,
+				(upper_u16 << 16) | output->phy.in_port))
+			goto nla_put_failure;
+	}
+
+	if (nla_put_u32(skb, OVS_KEY_ATTR_SKB_MARK, output->phy.skb_mark))
+		goto nla_put_failure;
+
+	nla = nla_reserve(skb, OVS_KEY_ATTR_ETHERNET, sizeof(*eth_key));
+	if (!nla)
+		goto nla_put_failure;
+
+	eth_key = nla_data(nla);
+	memcpy(eth_key->eth_src, output->eth.src, ETH_ALEN);
+	memcpy(eth_key->eth_dst, output->eth.dst, ETH_ALEN);
+
+	if (swkey->eth.tci || swkey->eth.type == htons(ETH_P_8021Q)) {
+		__be16 eth_type;
+		eth_type = !is_mask ? htons(ETH_P_8021Q) : htons(0xffff);
+		if (nla_put_be16(skb, OVS_KEY_ATTR_ETHERTYPE, eth_type) ||
+		    nla_put_be16(skb, OVS_KEY_ATTR_VLAN, output->eth.tci))
+			goto nla_put_failure;
+		encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
+		if (!swkey->eth.tci)
+			goto unencap;
+	} else
+		encap = NULL;
+
+	if (swkey->eth.type == htons(ETH_P_802_2)) {
+		/*
+		 * Ethertype 802.2 is represented in the netlink with omitted
+		 * OVS_KEY_ATTR_ETHERTYPE in the flow key attribute, and
+		 * 0xffff in the mask attribute.  Ethertype can also
+		 * be wildcarded.
+		 */
+		if (is_mask && output->eth.type)
+			if (nla_put_be16(skb, OVS_KEY_ATTR_ETHERTYPE,
+						output->eth.type))
+				goto nla_put_failure;
+		goto unencap;
+	}
+
+	if (nla_put_be16(skb, OVS_KEY_ATTR_ETHERTYPE, output->eth.type))
+		goto nla_put_failure;
+
+	if (swkey->eth.type == htons(ETH_P_IP)) {
+		struct ovs_key_ipv4 *ipv4_key;
+
+		nla = nla_reserve(skb, OVS_KEY_ATTR_IPV4, sizeof(*ipv4_key));
+		if (!nla)
+			goto nla_put_failure;
+		ipv4_key = nla_data(nla);
+		ipv4_key->ipv4_src = output->ipv4.addr.src;
+		ipv4_key->ipv4_dst = output->ipv4.addr.dst;
+		ipv4_key->ipv4_proto = output->ip.proto;
+		ipv4_key->ipv4_tos = output->ip.tos;
+		ipv4_key->ipv4_ttl = output->ip.ttl;
+		ipv4_key->ipv4_frag = output->ip.frag;
+	} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
+		struct ovs_key_ipv6 *ipv6_key;
+
+		nla = nla_reserve(skb, OVS_KEY_ATTR_IPV6, sizeof(*ipv6_key));
+		if (!nla)
+			goto nla_put_failure;
+		ipv6_key = nla_data(nla);
+		memcpy(ipv6_key->ipv6_src, &output->ipv6.addr.src,
+				sizeof(ipv6_key->ipv6_src));
+		memcpy(ipv6_key->ipv6_dst, &output->ipv6.addr.dst,
+				sizeof(ipv6_key->ipv6_dst));
+		ipv6_key->ipv6_label = output->ipv6.label;
+		ipv6_key->ipv6_proto = output->ip.proto;
+		ipv6_key->ipv6_tclass = output->ip.tos;
+		ipv6_key->ipv6_hlimit = output->ip.ttl;
+		ipv6_key->ipv6_frag = output->ip.frag;
+	} else if (swkey->eth.type == htons(ETH_P_ARP) ||
+		   swkey->eth.type == htons(ETH_P_RARP)) {
+		struct ovs_key_arp *arp_key;
+
+		nla = nla_reserve(skb, OVS_KEY_ATTR_ARP, sizeof(*arp_key));
+		if (!nla)
+			goto nla_put_failure;
+		arp_key = nla_data(nla);
+		memset(arp_key, 0, sizeof(struct ovs_key_arp));
+		arp_key->arp_sip = output->ipv4.addr.src;
+		arp_key->arp_tip = output->ipv4.addr.dst;
+		arp_key->arp_op = htons(output->ip.proto);
+		memcpy(arp_key->arp_sha, output->ipv4.arp.sha, ETH_ALEN);
+		memcpy(arp_key->arp_tha, output->ipv4.arp.tha, ETH_ALEN);
+	}
+
+	if ((swkey->eth.type == htons(ETH_P_IP) ||
+	     swkey->eth.type == htons(ETH_P_IPV6)) &&
+	     swkey->ip.frag != OVS_FRAG_TYPE_LATER) {
+
+		if (swkey->ip.proto == IPPROTO_TCP) {
+			struct ovs_key_tcp *tcp_key;
+
+			nla = nla_reserve(skb, OVS_KEY_ATTR_TCP, sizeof(*tcp_key));
+			if (!nla)
+				goto nla_put_failure;
+			tcp_key = nla_data(nla);
+			if (swkey->eth.type == htons(ETH_P_IP)) {
+				tcp_key->tcp_src = output->ipv4.tp.src;
+				tcp_key->tcp_dst = output->ipv4.tp.dst;
+			} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
+				tcp_key->tcp_src = output->ipv6.tp.src;
+				tcp_key->tcp_dst = output->ipv6.tp.dst;
+			}
+		} else if (swkey->ip.proto == IPPROTO_UDP) {
+			struct ovs_key_udp *udp_key;
+
+			nla = nla_reserve(skb, OVS_KEY_ATTR_UDP, sizeof(*udp_key));
+			if (!nla)
+				goto nla_put_failure;
+			udp_key = nla_data(nla);
+			if (swkey->eth.type == htons(ETH_P_IP)) {
+				udp_key->udp_src = output->ipv4.tp.src;
+				udp_key->udp_dst = output->ipv4.tp.dst;
+			} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
+				udp_key->udp_src = output->ipv6.tp.src;
+				udp_key->udp_dst = output->ipv6.tp.dst;
+			}
+		} else if (swkey->ip.proto == IPPROTO_SCTP) {
+			struct ovs_key_sctp *sctp_key;
+
+			nla = nla_reserve(skb, OVS_KEY_ATTR_SCTP, sizeof(*sctp_key));
+			if (!nla)
+				goto nla_put_failure;
+			sctp_key = nla_data(nla);
+			if (swkey->eth.type == htons(ETH_P_IP)) {
+				sctp_key->sctp_src = swkey->ipv4.tp.src;
+				sctp_key->sctp_dst = swkey->ipv4.tp.dst;
+			} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
+				sctp_key->sctp_src = swkey->ipv6.tp.src;
+				sctp_key->sctp_dst = swkey->ipv6.tp.dst;
+			}
+		} else if (swkey->eth.type == htons(ETH_P_IP) &&
+			   swkey->ip.proto == IPPROTO_ICMP) {
+			struct ovs_key_icmp *icmp_key;
+
+			nla = nla_reserve(skb, OVS_KEY_ATTR_ICMP, sizeof(*icmp_key));
+			if (!nla)
+				goto nla_put_failure;
+			icmp_key = nla_data(nla);
+			icmp_key->icmp_type = ntohs(output->ipv4.tp.src);
+			icmp_key->icmp_code = ntohs(output->ipv4.tp.dst);
+		} else if (swkey->eth.type == htons(ETH_P_IPV6) &&
+			   swkey->ip.proto == IPPROTO_ICMPV6) {
+			struct ovs_key_icmpv6 *icmpv6_key;
+
+			nla = nla_reserve(skb, OVS_KEY_ATTR_ICMPV6,
+						sizeof(*icmpv6_key));
+			if (!nla)
+				goto nla_put_failure;
+			icmpv6_key = nla_data(nla);
+			icmpv6_key->icmpv6_type = ntohs(output->ipv6.tp.src);
+			icmpv6_key->icmpv6_code = ntohs(output->ipv6.tp.dst);
+
+			if (icmpv6_key->icmpv6_type == NDISC_NEIGHBOUR_SOLICITATION ||
+			    icmpv6_key->icmpv6_type == NDISC_NEIGHBOUR_ADVERTISEMENT) {
+				struct ovs_key_nd *nd_key;
+
+				nla = nla_reserve(skb, OVS_KEY_ATTR_ND, sizeof(*nd_key));
+				if (!nla)
+					goto nla_put_failure;
+				nd_key = nla_data(nla);
+				memcpy(nd_key->nd_target, &output->ipv6.nd.target,
+							sizeof(nd_key->nd_target));
+				memcpy(nd_key->nd_sll, output->ipv6.nd.sll, ETH_ALEN);
+				memcpy(nd_key->nd_tll, output->ipv6.nd.tll, ETH_ALEN);
+			}
+		}
+	}
+
+unencap:
+	if (encap)
+		nla_nest_end(skb, encap);
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+/* Initializes the flow module.
+ * Returns zero if successful or a negative error code. */
+int ovs_flow_init(void)
+{
+	BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long));
+	BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long));
+
+	flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow), 0,
+					0, NULL);
+	if (flow_cache == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/* Uninitializes the flow module. */
+void ovs_flow_exit(void)
+{
+	kmem_cache_destroy(flow_cache);
+}
+
+struct sw_flow_mask *ovs_sw_flow_mask_alloc(void)
+{
+	struct sw_flow_mask *mask;
+
+	mask = kmalloc(sizeof(*mask), GFP_KERNEL);
+	if (mask)
+		mask->ref_count = 0;
+
+	return mask;
+}
+
+void ovs_sw_flow_mask_add_ref(struct sw_flow_mask *mask)
+{
+	mask->ref_count++;
+}
+
+void ovs_sw_flow_mask_del_ref(struct sw_flow_mask *mask, bool deferred)
+{
+	if (!mask)
+		return;
+
+	BUG_ON(!mask->ref_count);
+	mask->ref_count--;
+
+	if (!mask->ref_count) {
+		list_del_rcu(&mask->list);
+		if (deferred)
+			kfree_rcu(mask, rcu);
+		else
+			kfree(mask);
+	}
+}
+
+static bool ovs_sw_flow_mask_equal(const struct sw_flow_mask *a,
+		const struct sw_flow_mask *b)
+{
+	u8 *a_ = (u8 *)&a->key + a->range.start;
+	u8 *b_ = (u8 *)&b->key + b->range.start;
+
+	return  (a->range.end == b->range.end)
+		&& (a->range.start == b->range.start)
+		&& (memcmp(a_, b_, range_n_bytes(&a->range)) == 0);
+}
+
+struct sw_flow_mask *ovs_sw_flow_mask_find(const struct flow_table *tbl,
+                                           const struct sw_flow_mask *mask)
+{
+	struct list_head *ml;
+
+	list_for_each(ml, tbl->mask_list) {
+		struct sw_flow_mask *m;
+		m = container_of(ml, struct sw_flow_mask, list);
+		if (ovs_sw_flow_mask_equal(mask, m))
+			return m;
+	}
+
+	return NULL;
+}
+
+/**
+ * add a new mask into the mask list.
+ * The caller needs to make sure that 'mask' is not the same
+ * as any masks that are already on the list.
+ */
+void ovs_sw_flow_mask_insert(struct flow_table *tbl, struct sw_flow_mask *mask)
+{
+	list_add_rcu(&mask->list, tbl->mask_list);
+}
+
+/**
+ * Set 'range' fields in the mask to the value of 'val'.
+ */
+static void ovs_sw_flow_mask_set(struct sw_flow_mask *mask,
+		struct sw_flow_key_range *range, u8 val)
+{
+	u8 *m = (u8 *)&mask->key + range->start;
+
+	mask->range = *range;
+	memset(m, val, range_n_bytes(range));
+}