1 files changed, 592 insertions, 0 deletions

diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
new file mode 100644
index 000000000000..e42542706087
--- /dev/null
+++ b/net/openvswitch/flow_table.c
@@ -0,0 +1,592 @@
+/*
+ * 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>
+
+#include "datapath.h"
+
+#define TBL_MIN_BUCKETS         1024
+#define REHASH_INTERVAL         (10 * 60 * HZ)
+
+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;
+}
+
+int ovs_flow_tbl_count(struct flow_table *table)
+{
+        return table->count;
+}
+
+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);
+}
+
+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);
+}
+
+static void 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);
+        }
+}
+
+void ovs_flow_free(struct sw_flow *flow, bool deferred)
+{
+        if (!flow)
+                return;
+
+        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 __table_instance_destroy(struct table_instance *ti)
+{
+        int i;
+
+        if (ti->keep_flows)
+                goto skip_flows;
+
+        for (i = 0; i < ti->n_buckets; i++) {
+                struct sw_flow *flow;
+                struct hlist_head *head = flex_array_get(ti->buckets, i);
+                struct hlist_node *n;
+                int ver = ti->node_ver;
+
+                hlist_for_each_entry_safe(flow, n, head, hash_node[ver]) {
+                        hlist_del(&flow->hash_node[ver]);
+                        ovs_flow_free(flow, false);
+                }
+        }
+
+skip_flows:
+        free_buckets(ti->buckets);
+        kfree(ti);
+}
+
+static struct table_instance *table_instance_alloc(int new_size)
+{
+        struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
+
+        if (!ti)
+                return NULL;
+
+        ti->buckets = alloc_buckets(new_size);
+
+        if (!ti->buckets) {
+                kfree(ti);
+                return NULL;
+        }
+        ti->n_buckets = new_size;
+        ti->node_ver = 0;
+        ti->keep_flows = false;
+        get_random_bytes(&ti->hash_seed, sizeof(u32));
+
+        return ti;
+}
+
+int ovs_flow_tbl_init(struct flow_table *table)
+{
+        struct table_instance *ti;
+
+        ti = table_instance_alloc(TBL_MIN_BUCKETS);
+
+        if (!ti)
+                return -ENOMEM;
+
+        rcu_assign_pointer(table->ti, ti);
+        INIT_LIST_HEAD(&table->mask_list);
+        table->last_rehash = jiffies;
+        table->count = 0;
+        return 0;
+}
+
+static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
+{
+        struct table_instance *ti = container_of(rcu, struct table_instance, rcu);
+
+        __table_instance_destroy(ti);
+}
+
+static void table_instance_destroy(struct table_instance *ti, bool deferred)
+{
+        if (!ti)
+                return;
+
+        if (deferred)
+                call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
+        else
+                __table_instance_destroy(ti);
+}
+
+void ovs_flow_tbl_destroy(struct flow_table *table)
+{
+        struct table_instance *ti = ovsl_dereference(table->ti);
+
+        table_instance_destroy(ti, false);
+}
+
+struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
+                                       u32 *bucket, u32 *last)
+{
+        struct sw_flow *flow;
+        struct hlist_head *head;
+        int ver;
+        int i;
+
+        ver = ti->node_ver;
+        while (*bucket < ti->n_buckets) {
+                i = 0;
+                head = flex_array_get(ti->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 table_instance *ti, u32 hash)
+{
+        hash = jhash_1word(hash, ti->hash_seed);
+        return flex_array_get(ti->buckets,
+                                (hash & (ti->n_buckets - 1)));
+}
+
+static void table_instance_insert(struct table_instance *ti, struct sw_flow *flow)
+{
+        struct hlist_head *head;
+
+        head = find_bucket(ti, flow->hash);
+        hlist_add_head_rcu(&flow->hash_node[ti->node_ver], head);
+}
+
+static void flow_table_copy_flows(struct table_instance *old,
+                                  struct table_instance *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])
+                        table_instance_insert(new, flow);
+        }
+
+        old->keep_flows = true;
+}
+
+static struct table_instance *table_instance_rehash(struct table_instance *ti,
+                                            int n_buckets)
+{
+        struct table_instance *new_ti;
+
+        new_ti = table_instance_alloc(n_buckets);
+        if (!new_ti)
+                return NULL;
+
+        flow_table_copy_flows(ti, new_ti);
+
+        return new_ti;
+}
+
+int ovs_flow_tbl_flush(struct flow_table *flow_table)
+{
+        struct table_instance *old_ti;
+        struct table_instance *new_ti;
+
+        old_ti = ovsl_dereference(flow_table->ti);
+        new_ti = table_instance_alloc(TBL_MIN_BUCKETS);
+        if (!new_ti)
+                return -ENOMEM;
+
+        rcu_assign_pointer(flow_table->ti, new_ti);
+        flow_table->last_rehash = jiffies;
+        flow_table->count = 0;
+
+        table_instance_destroy(old_ti, true);
+        return 0;
+}
+
+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 table_instance *ti,
+                                          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(ti, hash);
+        hlist_for_each_entry_rcu(flow, head, hash_node[ti->node_ver]) {
+                if (flow->mask == mask && flow->hash == hash &&
+                    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,
+                                    u32 *n_mask_hit)
+{
+        struct table_instance *ti = rcu_dereference(tbl->ti);
+        struct sw_flow_mask *mask;
+        struct sw_flow *flow;
+
+        *n_mask_hit = 0;
+        list_for_each_entry_rcu(mask, &tbl->mask_list, list) {
+                (*n_mask_hit)++;
+                flow = masked_flow_lookup(ti, key, mask);
+                if (flow)  /* Found */
+                        return flow;
+        }
+        return NULL;
+}
+
+int ovs_flow_tbl_num_masks(const struct flow_table *table)
+{
+        struct sw_flow_mask *mask;
+        int num = 0;
+
+        list_for_each_entry(mask, &table->mask_list, list)
+                num++;
+
+        return num;
+}
+
+static struct table_instance *table_instance_expand(struct table_instance *ti)
+{
+        return table_instance_rehash(ti, ti->n_buckets * 2);
+}
+
+void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
+{
+        struct table_instance *ti = ovsl_dereference(table->ti);
+
+        BUG_ON(table->count == 0);
+        hlist_del_rcu(&flow->hash_node[ti->node_ver]);
+        table->count--;
+}
+
+static struct sw_flow_mask *mask_alloc(void)
+{
+        struct sw_flow_mask *mask;
+
+        mask = kmalloc(sizeof(*mask), GFP_KERNEL);
+        if (mask)
+                mask->ref_count = 0;
+
+        return mask;
+}
+
+static void mask_add_ref(struct sw_flow_mask *mask)
+{
+        mask->ref_count++;
+}
+
+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);
+}
+
+static struct sw_flow_mask *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.
+ */
+static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
+                            struct sw_flow_mask *new)
+{
+        struct sw_flow_mask *mask;
+        mask = flow_mask_find(tbl, new);
+        if (!mask) {
+                /* Allocate a new mask if none exsits. */
+                mask = mask_alloc();
+                if (!mask)
+                        return -ENOMEM;
+                mask->key = new->key;
+                mask->range = new->range;
+                list_add_rcu(&mask->list, &tbl->mask_list);
+        }
+
+        mask_add_ref(mask);
+        flow->mask = mask;
+        return 0;
+}
+
+int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
+                        struct sw_flow_mask *mask)
+{
+        struct table_instance *new_ti = NULL;
+        struct table_instance *ti;
+        int err;
+
+        err = flow_mask_insert(table, flow, mask);
+        if (err)
+                return err;
+
+        flow->hash = flow_hash(&flow->key, flow->mask->range.start,
+                        flow->mask->range.end);
+        ti = ovsl_dereference(table->ti);
+        table_instance_insert(ti, flow);
+        table->count++;
+
+        /* Expand table, if necessary, to make room. */
+        if (table->count > ti->n_buckets)
+                new_ti = table_instance_expand(ti);
+        else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL))
+                new_ti = table_instance_rehash(ti, ti->n_buckets);
+
+        if (new_ti) {
+                rcu_assign_pointer(table->ti, new_ti);
+                table_instance_destroy(ti, true);
+                table->last_rehash = jiffies;
+        }
+        return 0;
+}
+
+/* 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);
+}