cregit-Linux how code gets into the kernel

Release 4.8 net/openvswitch/flow_table.c

Directory: net/openvswitch
/*
 * 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/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; }

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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++; }

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daniele di proiettodaniele di proietto42.65%133.33%
Total151100.00%3100.00%


struct sw_flow *ovs_flow_alloc(void) { struct sw_flow *flow; struct flow_stats *stats; int node; flow = kmem_cache_alloc(flow_cache, GFP_KERNEL); if (!flow) return ERR_PTR(-ENOMEM); flow->sf_acts = NULL; flow->mask = NULL; flow->id.unmasked_key = NULL; flow->id.ufid_len = 0; flow->stats_last_writer = NUMA_NO_NODE; /* 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); for_each_node(node) if (node != 0) RCU_INIT_POINTER(flow->stats[node], NULL); return flow; err: kmem_cache_free(flow_cache, flow); return ERR_PTR(-ENOMEM); }

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konstantin khlebnikovkonstantin khlebnikov74.19%114.29%
wei yongjunwei yongjun31.80%114.29%
Total167100.00%7100.00%


int ovs_flow_tbl_count(const struct flow_table *table) { return table->count; }

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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; }

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static void flow_free(struct sw_flow *flow) { int node; 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); for_each_node(node) if (flow->stats[node]) kmem_cache_free(flow_stats_cache, (struct flow_stats __force *)flow->stats[node]); kmem_cache_free(flow_cache, flow); }

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joe stringerjoe stringer1921.11%116.67%
thomas grafthomas graf77.78%116.67%
Total90100.00%6100.00%


static void rcu_free_flow_callback(struct rcu_head *rcu) { struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu); flow_free(flow); }

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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); }

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static void free_buckets(struct flex_array *buckets) { flex_array_free(buckets); }

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static void __table_instance_destroy(struct table_instance *ti) { free_buckets(ti->buckets); kfree(ti); }

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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; }

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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; }

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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); }

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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); } }

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pravin b shelarpravin b shelar4020.62%250.00%
Total194100.00%4100.00%

/* 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); }

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Total43100.00%4100.00%


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; }

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Total116100.00%3100.00%


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))); }

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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); }

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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); }

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pravin b shelarpravin b shelar1835.29%266.67%
Total51100.00%3100.00%


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; }

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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; }

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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; }

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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); }

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daniele di proiettodaniele di proietto33.41%120.00%
daniel borkmanndaniel borkmann11.14%120.00%
Total88100.00%5100.00%


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)); }

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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; }

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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); }

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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); }

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thomas grafthomas graf11.41%133.33%
Total71100.00%3100.00%


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; }

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jesse grossjesse gross21.65%114.29%
thomas grafthomas graf10.83%114.29%
Total121100.00%7100.00%


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; }

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Total87100.00%5100.00%


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); }

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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; }

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thomas grafthomas graf11.12%133.33%
Total89100.00%3100.00%


static u32 ufid_hash(const struct sw_flow_id *sfid) { return jhash(sfid->ufid, sfid->ufid_len, 0); }

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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); }

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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); }

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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; }

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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; }

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static struct table_instance *table_instance_expand(struct table_instance *ti, bool ufid) { return table_instance_rehash(ti, ti->n_buckets * 2, ufid); }

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pravin b shelarpravin b shelar2583.33%150.00%
joe stringerjoe stringer516.67%150.00%
Total30100.00%2100.00%

/* 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); } } }

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/* 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