From e64457191a259537bbbfaebeba9a8043786af96f Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Thu, 3 Oct 2013 18:16:47 -0700 Subject: 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 Signed-off-by: Jesse Gross --- net/openvswitch/flow_table.c | 517 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 517 insertions(+) create mode 100644 net/openvswitch/flow_table.c (limited to 'net/openvswitch/flow_table.c') 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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); +} -- cgit v1.2.3