| // 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; |
| |
| /* 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; |
| ti->keep_flows = false; |
| get_random_bytes(&ti->hash_seed, sizeof(u32)); |
| |
| return ti; |
| } |
| |
| static void __mask_array_destroy(struct mask_array *ma) |
| { |
| free_percpu(ma->masks_usage_cntr); |
| 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) { |
| u64 *usage_counters = per_cpu_ptr(ma->masks_usage_cntr, |
| cpu); |
| unsigned int start; |
| u64 counter; |
| |
| do { |
| start = u64_stats_fetch_begin_irq(&ma->syncp); |
| counter = usage_counters[i]; |
| } while (u64_stats_fetch_retry_irq(&ma->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(sizeof(struct mask_array) + |
| sizeof(struct sw_flow_mask *) * size + |
| sizeof(u64) * size, GFP_KERNEL); |
| if (!new) |
| return NULL; |
| |
| new->masks_usage_zero_cntr = (u64 *)((u8 *)new + |
| sizeof(struct mask_array) + |
| sizeof(struct sw_flow_mask *) * |
| size); |
| |
| new->masks_usage_cntr = __alloc_percpu(sizeof(u64) * size, |
| __alignof__(u64)); |
| if (!new->masks_usage_cntr) { |
| 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(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 = 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, |
| bool count) |
| { |
| hlist_del_rcu(&flow->flow_table.node[ti->node_ver]); |
| if (count) |
| table->count--; |
| |
| if (ovs_identifier_is_ufid(&flow->id)) { |
| hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]); |
| |
| if (count) |
| 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; |
| |
| if (ti->keep_flows) |
| return; |
| |
| for (i = 0; i < ti->n_buckets; i++) { |
| struct sw_flow *flow; |
| struct hlist_head *head = &ti->buckets[i]; |
| struct hlist_node *n; |
| |
| hlist_for_each_entry_safe(flow, n, head, |
| flow_table.node[ti->node_ver]) { |
| |
| table_instance_flow_free(table, ti, ufid_ti, |
| flow, false); |
| ovs_flow_free(flow, true); |
| } |
| } |
| } |
| |
| 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); |
| } |
| |
| 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_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); |
| 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, |
| 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. |
| */ |
| 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) |
| { |
| u64 *usage_counters = this_cpu_ptr(ma->masks_usage_cntr); |
| 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(&ma->syncp); |
| usage_counters[*index]++; |
| u64_stats_update_end(&ma->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(&ma->syncp); |
| usage_counters[*index]++; |
| u64_stats_update_end(&ma->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; |
| u32 index = 0; |
| |
| return flow_lookup(tbl, ti, ma, key, &n_mask_hit, &n_cache_hit, &index); |
| } |
| |
| 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, true); |
| } |
| |
| 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 exsits. */ |
| 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; |
| unsigned int start; |
| 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) { |
| u64 *usage_counters = per_cpu_ptr(ma->masks_usage_cntr, |
| cpu); |
| u64 counter; |
| |
| do { |
| start = u64_stats_fetch_begin_irq(&ma->syncp); |
| counter = usage_counters[i]; |
| } while (u64_stats_fetch_retry_irq(&ma->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 *)), |
| 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); |
| } |