diff options
Diffstat (limited to 'net/openvswitch/flow_table.c')
| -rw-r--r-- | net/openvswitch/flow_table.c | 777 |
1 files changed, 777 insertions, 0 deletions
diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c new file mode 100644 index 000000000..80ea2a718 --- /dev/null +++ b/net/openvswitch/flow_table.c @@ -0,0 +1,777 @@ +/* + * 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 "flow.h" +#include "datapath.h" +#include "flow_netlink.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/cpumask.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> + +#define TBL_MIN_BUCKETS 1024 +#define REHASH_INTERVAL (10 * 60 * HZ) + +static struct kmem_cache *flow_cache; +struct kmem_cache *flow_stats_cache __read_mostly; + +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, + bool full, const struct sw_flow_mask *mask) +{ + int start = full ? 0 : mask->range.start; + int len = full ? sizeof *dst : range_n_bytes(&mask->range); + const long *m = (const long *)((const u8 *)&mask->key + start); + const long *s = (const long *)((const u8 *)src + start); + long *d = (long *)((u8 *)dst + start); + int i; + + /* If 'full' is true then all of 'dst' is fully initialized. Otherwise, + * if 'full' is false the memory outside of the 'mask->range' is left + * uninitialized. This can be used as an optimization when further + * operations on 'dst' only use contents within 'mask->range'. + */ + for (i = 0; i < len; i += sizeof(long)) + *d++ = *s++ & *m++; +} + +struct sw_flow *ovs_flow_alloc(void) +{ + struct sw_flow *flow; + struct flow_stats *stats; + + flow = kmem_cache_zalloc(flow_cache, GFP_KERNEL); + if (!flow) + return ERR_PTR(-ENOMEM); + + flow->stats_last_writer = -1; + + /* Initialize the default stat node. */ + stats = kmem_cache_alloc_node(flow_stats_cache, + GFP_KERNEL | __GFP_ZERO, + node_online(0) ? 0 : NUMA_NO_NODE); + if (!stats) + goto err; + + spin_lock_init(&stats->lock); + + RCU_INIT_POINTER(flow->stats[0], stats); + + cpumask_set_cpu(0, &flow->cpu_used_mask); + + return flow; +err: + kmem_cache_free(flow_cache, flow); + return ERR_PTR(-ENOMEM); +} + +int ovs_flow_tbl_count(const 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) +{ + int cpu; + + if (ovs_identifier_is_key(&flow->id)) + kfree(flow->id.unmasked_key); + if (flow->sf_acts) + ovs_nla_free_flow_actions((struct sw_flow_actions __force *)flow->sf_acts); + /* 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)) + if (flow->stats[cpu]) + kmem_cache_free(flow_stats_cache, + (struct flow_stats __force *)flow->stats[cpu]); + 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; + + 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) +{ + 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, *ufid_ti; + + ti = table_instance_alloc(TBL_MIN_BUCKETS); + + if (!ti) + return -ENOMEM; + + ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS); + if (!ufid_ti) + goto free_ti; + + rcu_assign_pointer(table->ti, ti); + rcu_assign_pointer(table->ufid_ti, ufid_ti); + INIT_LIST_HEAD(&table->mask_list); + table->last_rehash = jiffies; + table->count = 0; + table->ufid_count = 0; + return 0; + +free_ti: + __table_instance_destroy(ti); + return -ENOMEM; +} + +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, + struct table_instance *ufid_ti, + bool deferred) +{ + int i; + + if (!ti) + return; + + BUG_ON(!ufid_ti); + 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; + int ufid_ver = ufid_ti->node_ver; + + hlist_for_each_entry_safe(flow, n, head, flow_table.node[ver]) { + hlist_del_rcu(&flow->flow_table.node[ver]); + if (ovs_identifier_is_ufid(&flow->id)) + hlist_del_rcu(&flow->ufid_table.node[ufid_ver]); + ovs_flow_free(flow, deferred); + } + } + +skip_flows: + if (deferred) { + call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); + call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb); + } else { + __table_instance_destroy(ti); + __table_instance_destroy(ufid_ti); + } +} + +/* No need for locking this function is called from RCU callback or + * error path. + */ +void ovs_flow_tbl_destroy(struct flow_table *table) +{ + struct table_instance *ti = rcu_dereference_raw(table->ti); + struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti); + + table_instance_destroy(ti, ufid_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, flow_table.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->flow_table.hash); + hlist_add_head_rcu(&flow->flow_table.node[ti->node_ver], head); +} + +static void ufid_table_instance_insert(struct table_instance *ti, + struct sw_flow *flow) +{ + struct hlist_head *head; + + head = find_bucket(ti, flow->ufid_table.hash); + hlist_add_head_rcu(&flow->ufid_table.node[ti->node_ver], head); +} + +static void flow_table_copy_flows(struct table_instance *old, + struct table_instance *new, bool ufid) +{ + 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); + + if (ufid) + hlist_for_each_entry(flow, head, + ufid_table.node[old_ver]) + ufid_table_instance_insert(new, flow); + else + hlist_for_each_entry(flow, head, + flow_table.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, bool ufid) +{ + struct table_instance *new_ti; + + new_ti = table_instance_alloc(n_buckets); + if (!new_ti) + return NULL; + + flow_table_copy_flows(ti, new_ti, ufid); + + return new_ti; +} + +int ovs_flow_tbl_flush(struct flow_table *flow_table) +{ + struct table_instance *old_ti, *new_ti; + struct table_instance *old_ufid_ti, *new_ufid_ti; + + new_ti = table_instance_alloc(TBL_MIN_BUCKETS); + if (!new_ti) + return -ENOMEM; + new_ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS); + if (!new_ufid_ti) + goto err_free_ti; + + old_ti = ovsl_dereference(flow_table->ti); + old_ufid_ti = ovsl_dereference(flow_table->ufid_ti); + + rcu_assign_pointer(flow_table->ti, new_ti); + rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti); + flow_table->last_rehash = jiffies; + flow_table->count = 0; + flow_table->ufid_count = 0; + + table_instance_destroy(old_ti, old_ufid_ti, true); + return 0; + +err_free_ti: + __table_instance_destroy(new_ti); + return -ENOMEM; +} + +static u32 flow_hash(const struct sw_flow_key *key, + const struct sw_flow_key_range *range) +{ + int key_start = range->start; + int key_end = range->end; + const u32 *hash_key = (const u32 *)((const 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_proto) + 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 = (const long *)((const u8 *)key1 + key_start); + const long *cp2 = (const long *)((const 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, + const struct sw_flow_key_range *range) +{ + return cmp_key(&flow->key, key, range->start, range->end); +} + +static bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow, + const 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; + + BUG_ON(ovs_identifier_is_ufid(&flow->id)); + return cmp_key(flow->id.unmasked_key, key, key_start, key_end); +} + +static struct sw_flow *masked_flow_lookup(struct table_instance *ti, + const struct sw_flow_key *unmasked, + const struct sw_flow_mask *mask) +{ + struct sw_flow *flow; + struct hlist_head *head; + u32 hash; + struct sw_flow_key masked_key; + + ovs_flow_mask_key(&masked_key, unmasked, false, mask); + hash = flow_hash(&masked_key, &mask->range); + head = find_bucket(ti, hash); + hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver]) { + if (flow->mask == mask && flow->flow_table.hash == hash && + flow_cmp_masked_key(flow, &masked_key, &mask->range)) + return flow; + } + return NULL; +} + +struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl, + const struct sw_flow_key *key, + u32 *n_mask_hit) +{ + struct table_instance *ti = rcu_dereference_ovsl(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; +} + +struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl, + const struct sw_flow_key *key) +{ + u32 __always_unused n_mask_hit; + + return ovs_flow_tbl_lookup_stats(tbl, key, &n_mask_hit); +} + +struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl, + const struct sw_flow_match *match) +{ + struct table_instance *ti = rcu_dereference_ovsl(tbl->ti); + struct sw_flow_mask *mask; + struct sw_flow *flow; + + /* Always called under ovs-mutex. */ + list_for_each_entry(mask, &tbl->mask_list, list) { + flow = masked_flow_lookup(ti, match->key, mask); + if (flow && ovs_identifier_is_key(&flow->id) && + ovs_flow_cmp_unmasked_key(flow, match)) + return flow; + } + return NULL; +} + +static u32 ufid_hash(const struct sw_flow_id *sfid) +{ + return jhash(sfid->ufid, sfid->ufid_len, 0); +} + +static bool ovs_flow_cmp_ufid(const struct sw_flow *flow, + const struct sw_flow_id *sfid) +{ + if (flow->id.ufid_len != sfid->ufid_len) + return false; + + return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len); +} + +bool ovs_flow_cmp(const struct sw_flow *flow, const struct sw_flow_match *match) +{ + if (ovs_identifier_is_ufid(&flow->id)) + return flow_cmp_masked_key(flow, match->key, &match->range); + + return ovs_flow_cmp_unmasked_key(flow, match); +} + +struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl, + const struct sw_flow_id *ufid) +{ + struct table_instance *ti = rcu_dereference_ovsl(tbl->ufid_ti); + struct sw_flow *flow; + struct hlist_head *head; + u32 hash; + + hash = ufid_hash(ufid); + head = find_bucket(ti, hash); + hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver]) { + if (flow->ufid_table.hash == hash && + ovs_flow_cmp_ufid(flow, ufid)) + 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, + bool ufid) +{ + return table_instance_rehash(ti, ti->n_buckets * 2, ufid); +} + +/* Remove 'mask' from the mask list, if it is not needed any more. */ +static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask) +{ + if (mask) { + /* ovs-lock is required to protect mask-refcount and + * mask list. + */ + ASSERT_OVSL(); + BUG_ON(!mask->ref_count); + mask->ref_count--; + + if (!mask->ref_count) { + list_del_rcu(&mask->list); + kfree_rcu(mask, rcu); + } + } +} + +/* Must be called with OVS mutex held. */ +void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow) +{ + struct table_instance *ti = ovsl_dereference(table->ti); + struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti); + + BUG_ON(table->count == 0); + hlist_del_rcu(&flow->flow_table.node[ti->node_ver]); + table->count--; + if (ovs_identifier_is_ufid(&flow->id)) { + hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]); + table->ufid_count--; + } + + /* RCU delete the mask. 'flow->mask' is not NULLed, as it should be + * accessible as long as the RCU read lock is held. + */ + flow_mask_remove(table, flow->mask); +} + +static struct sw_flow_mask *mask_alloc(void) +{ + struct sw_flow_mask *mask; + + mask = kmalloc(sizeof(*mask), GFP_KERNEL); + if (mask) + mask->ref_count = 1; + + return mask; +} + +static bool mask_equal(const struct sw_flow_mask *a, + const struct sw_flow_mask *b) +{ + const u8 *a_ = (const u8 *)&a->key + a->range.start; + const u8 *b_ = (const 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 'mask' into the mask list, if it is not already there. */ +static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow, + const 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); + } else { + BUG_ON(!mask->ref_count); + mask->ref_count++; + } + + flow->mask = mask; + return 0; +} + +/* Must be called with OVS mutex held. */ +static void flow_key_insert(struct flow_table *table, struct sw_flow *flow) +{ + struct table_instance *new_ti = NULL; + struct table_instance *ti; + + flow->flow_table.hash = flow_hash(&flow->key, &flow->mask->range); + 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, false); + else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL)) + new_ti = table_instance_rehash(ti, ti->n_buckets, false); + + if (new_ti) { + rcu_assign_pointer(table->ti, new_ti); + call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); + table->last_rehash = jiffies; + } +} + +/* Must be called with OVS mutex held. */ +static void flow_ufid_insert(struct flow_table *table, struct sw_flow *flow) +{ + struct table_instance *ti; + + flow->ufid_table.hash = ufid_hash(&flow->id); + ti = ovsl_dereference(table->ufid_ti); + ufid_table_instance_insert(ti, flow); + table->ufid_count++; + + /* Expand table, if necessary, to make room. */ + if (table->ufid_count > ti->n_buckets) { + struct table_instance *new_ti; + + new_ti = table_instance_expand(ti, true); + if (new_ti) { + rcu_assign_pointer(table->ufid_ti, new_ti); + call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); + } + } +} + +/* Must be called with OVS mutex held. */ +int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow, + const struct sw_flow_mask *mask) +{ + int err; + + err = flow_mask_insert(table, flow, mask); + if (err) + return err; + flow_key_insert(table, flow); + if (ovs_identifier_is_ufid(&flow->id)) + flow_ufid_insert(table, flow); + + 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) + + (nr_cpu_ids + * sizeof(struct flow_stats *)), + 0, 0, NULL); + if (flow_cache == NULL) + return -ENOMEM; + + flow_stats_cache + = kmem_cache_create("sw_flow_stats", sizeof(struct flow_stats), + 0, SLAB_HWCACHE_ALIGN, NULL); + if (flow_stats_cache == NULL) { + kmem_cache_destroy(flow_cache); + flow_cache = NULL; + return -ENOMEM; + } + + return 0; +} + +/* Uninitializes the flow module. */ +void ovs_flow_exit(void) +{ + kmem_cache_destroy(flow_stats_cache); + kmem_cache_destroy(flow_cache); +} |