// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2007-2014 Nicira, Inc.
*/
#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 <linux/sort.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/ndisc.h>
#define TBL_MIN_BUCKETS 1024
#define MASK_ARRAY_SIZE_MIN 16
#define REHASH_INTERVAL (10 * 60 * HZ)
#define MC_DEFAULT_HASH_ENTRIES 256
#define MC_HASH_SHIFT 8
#define MC_HASH_SEGS ((sizeof(uint32_t) * 8) / MC_HASH_SHIFT)
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 sw_flow_stats *stats;
flow = kmem_cache_zalloc(flow_cache, GFP_KERNEL);
if (!flow)
return ERR_PTR(-ENOMEM);
flow->stats_last_writer = -1;
flow->cpu_used_mask = (struct cpumask *)&flow->stats[nr_cpu_ids];
/* 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 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 sw_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 __table_instance_destroy(struct table_instance *ti)
{
kvfree(ti->buckets);
kfree(ti);
}
static struct table_instance *table_instance_alloc(int new_size)
{
struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
int i;
if (!ti)
return NULL;
ti->buckets = kvmalloc_array(new_size, sizeof(struct hlist_head),
GFP_KERNEL);
if (!ti->buckets) {
kfree(ti);
return NULL;
}
for (i = 0; i < new_size; i++)
INIT_HLIST_HEAD(&ti->buckets[i]);
ti->n_buckets = new_size;
ti->node_ver = 0;
get_random_bytes(&ti->hash_seed, sizeof(u32));
return ti;
}
static void __mask_array_destroy(struct mask_array *ma)
{
free_percpu(ma->masks_usage_stats);
kfree(ma);
}
static void mask_array_rcu_cb(struct rcu_head *rcu)
{
struct mask_array *ma = container_of(rcu, struct mask_array, rcu);
__mask_array_destroy(ma);
}
static void tbl_mask_array_reset_counters(struct mask_array *ma)
{
int i, cpu;
/* As the per CPU counters are not atomic we can not go ahead and
* reset them from another CPU. To be able to still have an approximate
* zero based counter we store the value at reset, and subtract it
* later when processing.
*/
for (i = 0; i < ma->max; i++) {
ma->masks_usage_zero_cntr[i] = 0;
for_each_possible_cpu(cpu) {
struct mask_array_stats *stats;
unsigned int start;
u64 counter;
stats = per_cpu_ptr(ma->masks_usage_stats, cpu);
do {
start = u64_stats_fetch_begin(&stats->syncp);
counter = stats->usage_cntrs[i];
} while (u64_stats_fetch_retry(&stats->syncp, start));
ma->masks_usage_zero_cntr[i] += counter;
}
}
}
static struct mask_array *tbl_mask_array_alloc(int size)
{
struct mask_array *new;
size = max(MASK_ARRAY_SIZE_MIN, size);
new = kzalloc(struct_size(new, masks, size) +
sizeof(u64) * size, GFP_KERNEL);
if (!new)
return NULL;
new->masks_usage_zero_cntr = (u64 *)((u8 *)new +
struct_size(new, masks, size));
new->masks_usage_stats = __alloc_percpu(sizeof(struct mask_array_stats) +
sizeof(u64) * size,
__alignof__(u64));
if (!new->masks_usage_stats) {
kfree(new);
return NULL;
}
new->count = 0;
new->max = size;
return new;
}
static int tbl_mask_array_realloc(struct flow_table *tbl, int size)
{
struct mask_array *old;
struct mask_array *new;
new = tbl_mask_array_alloc(size);
if (!new)
return -ENOMEM;
old = ovsl_dereference(tbl->mask_array);
if (old) {
int i;
for (i = 0; i < old->max; i++) {
if (ovsl_dereference(old->masks[i]))
new->masks[new->count++] = old->masks[i];
}
call_rcu(&old->rcu, mask_array_rcu_cb);
}
rcu_assign_pointer(tbl->mask_array, new);
return 0;
}
static int tbl_mask_array_add_mask(struct flow_table *tbl,
struct sw_flow_mask *new)
{
struct mask_array *ma = ovsl_dereference(tbl->mask_array);
int err, ma_count = READ_ONCE(ma->count);
if (ma_count >= ma->max) {
err = tbl_mask_array_realloc(tbl, ma->max +
MASK_ARRAY_SIZE_MIN);
if (err)
return err;
ma = ovsl_dereference(tbl->mask_array);
} else {
/* On every add or delete we need to reset the counters so
* every new mask gets a fair chance of being prioritized.
*/
tbl_mask_array_reset_counters(ma);
}
BUG_ON(ovsl_dereference(ma->masks[ma_count]));
rcu_assign_pointer(ma->masks[ma_count], new);
WRITE_ONCE(ma->count, ma_count + 1);
return 0;
}
static void tbl_mask_array_del_mask(struct flow_table *tbl,
struct sw_flow_mask *mask)
{
struct mask_array *ma = ovsl_dereference(tbl->mask_array);
int i, ma_count = READ_ONCE(ma->count);
/* Remove the deleted mask pointers from the array */
for (i = 0; i < ma_count; i++) {
if (mask == ovsl_dereference(ma->masks[i]))
goto found;
}
BUG();
return;
found:
WRITE_ONCE(ma->count, ma_count - 1);
rcu_assign_pointer(ma->masks[i], ma->masks[ma_count - 1]);
RCU_INIT_POINTER(ma->masks[ma_count - 1], NULL);
kfree_rcu(mask, rcu);
/* Shrink the mask array if necessary. */
if (ma->max >= (MASK_ARRAY_SIZE_MIN * 2) &&
ma_count <= (ma->max / 3))
tbl_mask_array_realloc(tbl, ma->max / 2);
else
tbl_mask_array_reset_counters(ma);
}
/* 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)
tbl_mask_array_del_mask(tbl, mask);
}
}
static void __mask_cache_destroy(struct mask_cache *mc)
{
free_percpu(mc->mask_cache);
kfree(mc);
}
static void mask_cache_rcu_cb(struct rcu_head *rcu)
{
struct mask_cache *mc = container_of(rcu, struct mask_cache, rcu);
__mask_cache_destroy(mc);
}
static struct mask_cache *tbl_mask_cache_alloc(u32 size)
{
struct mask_cache_entry __percpu *cache = NULL;
struct mask_cache *new;
/* Only allow size to be 0, or a power of 2, and does not exceed
* percpu allocation size.
*/
if ((!is_power_of_2(size) && size != 0) ||
(size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
return NULL;
new = kzalloc(sizeof(*new), GFP_KERNEL);
if (!new)
return NULL;
new->cache_size = size;
if (new->cache_size > 0) {
cache = __alloc_percpu(array_size(sizeof(struct mask_cache_entry),
new->cache_size),
__alignof__(struct mask_cache_entry));
if (!cache) {
kfree(new);
return NULL;
}
}
new->mask_cache = cache;
return new;
}
int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 size)
{
struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
struct mask_cache *new;
if (size == mc->cache_size)
return 0;
if ((!is_power_of_2(size) && size != 0) ||
(size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
return -EINVAL;
new = tbl_mask_cache_alloc(size);
if (!new)
return -ENOMEM;
rcu_assign_pointer(table->mask_cache, new);
call_rcu(&mc->rcu, mask_cache_rcu_cb);
return 0;
}
int ovs_flow_tbl_init(struct flow_table *table)
{
struct table_instance *ti, *ufid_ti;
struct mask_cache *mc;
struct mask_array *ma;
mc = tbl_mask_cache_alloc(MC_DEFAULT_HASH_ENTRIES);
if (!mc)
return -ENOMEM;
ma = tbl_mask_array_alloc(MASK_ARRAY_SIZE_MIN);
if (!ma)
goto free_mask_cache;
ti = table_instance_alloc(TBL_MIN_BUCKETS);
if (!ti)
goto free_mask_array;
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);
rcu_assign_pointer(table->mask_array, ma);
rcu_assign_pointer(table->mask_cache, mc);
table->last_rehash = jiffies;
table->count = 0;
table->ufid_count = 0;
return 0;
free_ti:
__table_instance_destroy(ti);
free_mask_array:
__mask_array_destroy(ma);
free_mask_cache:
__mask_cache_destroy(mc);
return -ENOMEM;
}
static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
{
struct table_instance *ti;
ti = container_of(rcu, struct table_instance, rcu);
__table_instance_destroy(ti);
}
static void table_instance_flow_free(struct flow_table *table,
struct table_instance *ti,
struct table_instance *ufid_ti,
struct sw_flow *flow)
{
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--;
}
flow_mask_remove(table, flow->mask);
}
/* Must be called with OVS mutex held. */
void table_instance_flow_flush(struct flow_table *table,
struct table_instance *ti,
struct table_instance *ufid_ti)
{
int i;
for (i = 0; i < ti->n_buckets; i++) {
struct hlist_head *head = &ti->buckets[i];
struct hlist_node *n;
struct sw_flow *flow;
hlist_for_each_entry_safe(flow, n, head,
flow_table.node[ti->node_ver]) {
table_instance_flow_free(table, ti, ufid_ti,
flow);
ovs_flow_free(flow, true);
}
}
if (WARN_ON(table->count != 0 ||
table->ufid_count != 0)) {
table->count = 0;
table->ufid_count = 0;
}
}
static void table_instance_destroy(struct table_instance *ti,
struct table_instance *ufid_ti)
{
call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb);
}
/* 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);
struct mask_cache *mc = rcu_dereference_raw(table->mask_cache);
struct mask_array *ma = rcu_dereference_raw(table->mask_array);
call_rcu(&mc->rcu, mask_cache_rcu_cb);
call_rcu(&ma->rcu, mask_array_rcu_cb);
table_instance_destroy(ti, ufid_ti);
}
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 = &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 &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 = &old->buckets[i];
if (ufid)
hlist_for_each_entry_rcu(flow, head,
ufid_table.node[old_ver],
lockdep_ovsl_is_held())
ufid_table_instance_insert(new, flow);
else
hlist_for_each_entry_rcu(flow, head,
flow_table.node[old_ver],
lockdep_ovsl_is_held())
table_instance_insert(new, flow);
}
}
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;
table_instance_flow_flush(flow_table, old_ti, old_ufid_ti);
table_instance_destroy(old_ti, old_ufid_ti);
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)
{
const u32 *hash_key = (const u32 *)((const u8 *)key + range->start);
/* Make sure number of hash bytes are multiple of u32. */
int hash_u32s = range_n_bytes(range) >> 2;
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);
int i;
for (i = key_start; i < key_end; i += sizeof(long))
if (*cp1++ ^ *cp2++)
return false;
return true;
}
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,
u32 *n_mask_hit)
{
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);
(*n_mask_hit)++;
hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver],
lockdep_ovsl_is_held()) {
if (flow->mask == mask && flow->flow_table.hash == hash &&
flow_cmp_masked_key(flow, &masked_key, &mask->range))
return flow;
}
return NULL;
}
/* Flow lookup does full lookup on flow table. It starts with
* mask from index passed in *index.
* This function MUST be called with BH disabled due to the use
* of CPU specific variables.
*/
static struct sw_flow *flow_lookup(struct flow_table *tbl,
struct table_instance *ti,
struct mask_array *ma,
const struct sw_flow_key *key,
u32 *n_mask_hit,
u32 *n_cache_hit,
u32 *index)
{
struct mask_array_stats *stats = this_cpu_ptr(ma->masks_usage_stats);
struct sw_flow *flow;
struct sw_flow_mask *mask;
int i;
if (likely(*index < ma->max)) {
mask = rcu_dereference_ovsl(ma->masks[*index]);
if (mask) {
flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
if (flow) {
u64_stats_update_begin(&stats->syncp);
stats->usage_cntrs[*index]++;
u64_stats_update_end(&stats->syncp);
(*n_cache_hit)++;
return flow;
}
}
}
for (i = 0; i < ma->max; i++) {
if (i == *index)
continue;
mask = rcu_dereference_ovsl(ma->masks[i]);
if (unlikely(!mask))
break;
flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
if (flow) { /* Found */
*index = i;
u64_stats_update_begin(&stats->syncp);
stats->usage_cntrs[*index]++;
u64_stats_update_end(&stats->syncp);
return flow;
}
}
return NULL;
}
/*
* mask_cache maps flow to probable mask. This cache is not tightly
* coupled cache, It means updates to mask list can result in inconsistent
* cache entry in mask cache.
* This is per cpu cache and is divided in MC_HASH_SEGS segments.
* In case of a hash collision the entry is hashed in next segment.
* */
struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
const struct sw_flow_key *key,
u32 skb_hash,
u32 *n_mask_hit,
u32 *n_cache_hit)
{
struct mask_cache *mc = rcu_dereference(tbl->mask_cache);
struct mask_array *ma = rcu_dereference(tbl->mask_array);
struct table_instance *ti = rcu_dereference(tbl->ti);
struct mask_cache_entry *entries, *ce;
struct sw_flow *flow;
u32 hash;
int seg;
*n_mask_hit = 0;
*n_cache_hit = 0;
if (unlikely(!skb_hash || mc->cache_size == 0)) {
u32 mask_index = 0;
u32 cache = 0;
return flow_lookup(tbl, ti, ma, key, n_mask_hit, &cache,
&mask_index);
}
/* Pre and post recirulation flows usually have the same skb_hash
* value. To avoid hash collisions, rehash the 'skb_hash' with
* 'recirc_id'. */
if (key->recirc_id)
skb_hash = jhash_1word(skb_hash, key->recirc_id);
ce = NULL;
hash = skb_hash;
entries = this_cpu_ptr(mc->mask_cache);
/* Find the cache entry 'ce' to operate on. */
for (seg = 0; seg < MC_HASH_SEGS; seg++) {
int index = hash & (mc->cache_size - 1);
struct mask_cache_entry *e;
e = &entries[index];
if (e->skb_hash == skb_hash) {
flow = flow_lookup(tbl, ti, ma, key, n_mask_hit,
n_cache_hit, &e->mask_index);
if (!flow)
e->skb_hash = 0;
return flow;
}
if (!ce || e->skb_hash < ce->skb_hash)
ce = e; /* A better replacement cache candidate. */
hash >>= MC_HASH_SHIFT;
}
/* Cache miss, do full lookup. */
flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, n_cache_hit,
&ce->mask_index);
if (flow)
ce->skb_hash = skb_hash;
*n_cache_hit = 0;
return flow;
}
struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
const struct sw_flow_key *key)
{
struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
struct mask_array *ma = rcu_dereference_ovsl(tbl->mask_array);
u32 __always_unused n_mask_hit;
u32 __always_unused n_cache_hit;
struct sw_flow *flow;
u32 index = 0;
/* This function gets called trough the netlink interface and therefore
* is preemptible. However, flow_lookup() function needs to be called
* with BH disabled due to CPU specific variables.
*/
local_bh_disable();
flow = flow_lookup(tbl, ti, ma, key, &n_mask_hit, &n_cache_hit, &index);
local_bh_enable();
return flow;
}
struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
const struct sw_flow_match *match)
{
struct mask_array *ma = ovsl_dereference(tbl->mask_array);
int i;
/* Always called under ovs-mutex. */
for (i = 0; i < ma->max; i++) {
struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
u32 __always_unused n_mask_hit;
struct sw_flow_mask *mask;
struct sw_flow *flow;
mask = ovsl_dereference(ma->masks[i]);
if (!mask)
continue;
flow = masked_flow_lookup(ti, match->key, mask, &n_mask_hit);
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],
lockdep_ovsl_is_held()) {
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 mask_array *ma = rcu_dereference_ovsl(table->mask_array);
return READ_ONCE(ma->count);
}
u32 ovs_flow_tbl_masks_cache_size(const struct flow_table *table)
{
struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
return READ_ONCE(mc->cache_size);
}
static struct table_instance *table_instance_expand(struct table_instance *ti,
bool ufid)
{
return table_instance_rehash(ti, ti->n_buckets * 2, ufid);
}
/* 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);
table_instance_flow_free(table, ti, ufid_ti, flow);
}
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 mask_array *ma;
int i;
ma = ovsl_dereference(tbl->mask_array);
for (i = 0; i < ma->max; i++) {
struct sw_flow_mask *t;
t = ovsl_dereference(ma->masks[i]);
if (t && mask_equal(mask, t))
return t;
}
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 exists. */
mask = mask_alloc();
if (!mask)
return -ENOMEM;
mask->key = new->key;
mask->range = new->range;
/* Add mask to mask-list. */
if (tbl_mask_array_add_mask(tbl, mask)) {
kfree(mask);
return -ENOMEM;
}
} 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;
}
static int compare_mask_and_count(const void *a, const void *b)
{
const struct mask_count *mc_a = a;
const struct mask_count *mc_b = b;
return (s64)mc_b->counter - (s64)mc_a->counter;
}
/* Must be called with OVS mutex held. */
void ovs_flow_masks_rebalance(struct flow_table *table)
{
struct mask_array *ma = rcu_dereference_ovsl(table->mask_array);
struct mask_count *masks_and_count;
struct mask_array *new;
int masks_entries = 0;
int i;
/* Build array of all current entries with use counters. */
masks_and_count = kmalloc_array(ma->max, sizeof(*masks_and_count),
GFP_KERNEL);
if (!masks_and_count)
return;
for (i = 0; i < ma->max; i++) {
struct sw_flow_mask *mask;
int cpu;
mask = rcu_dereference_ovsl(ma->masks[i]);
if (unlikely(!mask))
break;
masks_and_count[i].index = i;
masks_and_count[i].counter = 0;
for_each_possible_cpu(cpu) {
struct mask_array_stats *stats;
unsigned int start;
u64 counter;
stats = per_cpu_ptr(ma->masks_usage_stats, cpu);
do {
start = u64_stats_fetch_begin(&stats->syncp);
counter = stats->usage_cntrs[i];
} while (u64_stats_fetch_retry(&stats->syncp, start));
masks_and_count[i].counter += counter;
}
/* Subtract the zero count value. */
masks_and_count[i].counter -= ma->masks_usage_zero_cntr[i];
/* Rather than calling tbl_mask_array_reset_counters()
* below when no change is needed, do it inline here.
*/
ma->masks_usage_zero_cntr[i] += masks_and_count[i].counter;
}
if (i == 0)
goto free_mask_entries;
/* Sort the entries */
masks_entries = i;
sort(masks_and_count, masks_entries, sizeof(*masks_and_count),
compare_mask_and_count, NULL);
/* If the order is the same, nothing to do... */
for (i = 0; i < masks_entries; i++) {
if (i != masks_and_count[i].index)
break;
}
if (i == masks_entries)
goto free_mask_entries;
/* Rebuilt the new list in order of usage. */
new = tbl_mask_array_alloc(ma->max);
if (!new)
goto free_mask_entries;
for (i = 0; i < masks_entries; i++) {
int index = masks_and_count[i].index;
if (ovsl_dereference(ma->masks[index]))
new->masks[new->count++] = ma->masks[index];
}
rcu_assign_pointer(table->mask_array, new);
call_rcu(&ma->rcu, mask_array_rcu_cb);
free_mask_entries:
kfree(masks_and_count);
}
/* 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 sw_flow_stats *))
+ cpumask_size(),
0, 0, NULL);
if (flow_cache == NULL)
return -ENOMEM;
flow_stats_cache
= kmem_cache_create("sw_flow_stats", sizeof(struct sw_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);
}
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