openvswitch: Restructure datapath.c and flow.c

Over the time datapath.c and flow.c has became pretty large files.
Following patch restructures functionality of component into three
different components:

flow.c: contains flow extract.
flow_netlink.c: netlink flow api.
flow_table.c: flow table api.

This patch restructures code without changing logic.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

1 files changed, 517 insertions, 0 deletions

diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
new file mode 100644
index 000000000000..dcadb75bb173
--- /dev/null
+++ b/net/openvswitch/flow_table.c
@@ -0,0 +1,517 @@
+/*
+ * Copyright (c) 2007-2013 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 "flow.h"
+#include "datapath.h"
+#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/if_arp.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/sctp.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/ipv6.h>
+#include <net/ndisc.h>
+
+static struct kmem_cache *flow_cache;
+
+static u16 range_n_bytes(const struct sw_flow_key_range *range)
+{
+	return range->end - range->start;
+}
+
+void ovs_flow_mask_key(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++;
+}
+
+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 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 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);
+}
+
+static void free_buckets(struct flex_array *buckets)
+{
+	flex_array_free(buckets);
+}
+
+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);
+}
+
+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;
+}
+
+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_tbl_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 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 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 u32 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);
+}
+
+bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
+			       struct sw_flow_match *match)
+{
+	struct sw_flow_key *key = match->key;
+	int key_start = flow_key_start(key);
+	int key_end = match->range.end;
+
+	return cmp_key(&flow->unmasked_key, key, key_start, key_end);
+}
+
+static struct sw_flow *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_mask_key(&masked_key, unmasked, mask);
+	hash = 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_tbl_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 = masked_flow_lookup(tbl, key, mask);
+		if (flow)  /* Found */
+			break;
+	}
+
+	return flow;
+}
+
+void ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow)
+{
+	flow->hash = flow_hash(&flow->key, flow->mask->range.start,
+			flow->mask->range.end);
+	__tbl_insert(table, flow);
+}
+
+void ovs_flow_tbl_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--;
+}
+
+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++;
+}
+
+static void rcu_free_sw_flow_mask_cb(struct rcu_head *rcu)
+{
+	struct sw_flow_mask *mask = container_of(rcu, struct sw_flow_mask, rcu);
+
+	kfree(mask);
+}
+
+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)
+			call_rcu(&mask->rcu, rcu_free_sw_flow_mask_cb);
+		else
+			kfree(mask);
+	}
+}
+
+static bool 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 (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);
+}
+
+/* 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);
+}