+++ /dev/null
-/* flow.c: Generic flow cache.
- *
- * Copyright (C) 2003 Alexey N. Kuznetsov (kuznet@ms2.inr.ac.ru)
- * Copyright (C) 2003 David S. Miller (davem@redhat.com)
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/list.h>
-#include <linux/jhash.h>
-#include <linux/interrupt.h>
-#include <linux/mm.h>
-#include <linux/random.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/smp.h>
-#include <linux/completion.h>
-#include <linux/percpu.h>
-#include <linux/bitops.h>
-#include <linux/notifier.h>
-#include <linux/cpu.h>
-#include <linux/cpumask.h>
-#include <linux/mutex.h>
-#include <net/flow.h>
-#include <linux/atomic.h>
-#include <linux/security.h>
-#include <net/net_namespace.h>
-
-struct flow_cache_entry {
- union {
- struct hlist_node hlist;
- struct list_head gc_list;
- } u;
- struct net *net;
- u16 family;
- u8 dir;
- u32 genid;
- struct flowi key;
- struct flow_cache_object *object;
-};
-
-struct flow_flush_info {
- struct flow_cache *cache;
- atomic_t cpuleft;
- struct completion completion;
-};
-
-static struct kmem_cache *flow_cachep __read_mostly;
-
-#define flow_cache_hash_size(cache) (1U << (cache)->hash_shift)
-#define FLOW_HASH_RND_PERIOD (10 * 60 * HZ)
-
-static void flow_cache_new_hashrnd(unsigned long arg)
-{
- struct flow_cache *fc = (void *) arg;
- int i;
-
- for_each_possible_cpu(i)
- per_cpu_ptr(fc->percpu, i)->hash_rnd_recalc = 1;
-
- fc->rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;
- add_timer(&fc->rnd_timer);
-}
-
-static int flow_entry_valid(struct flow_cache_entry *fle,
- struct netns_xfrm *xfrm)
-{
- if (atomic_read(&xfrm->flow_cache_genid) != fle->genid)
- return 0;
- if (fle->object && !fle->object->ops->check(fle->object))
- return 0;
- return 1;
-}
-
-static void flow_entry_kill(struct flow_cache_entry *fle,
- struct netns_xfrm *xfrm)
-{
- if (fle->object)
- fle->object->ops->delete(fle->object);
- kmem_cache_free(flow_cachep, fle);
-}
-
-static void flow_cache_gc_task(struct work_struct *work)
-{
- struct list_head gc_list;
- struct flow_cache_entry *fce, *n;
- struct netns_xfrm *xfrm = container_of(work, struct netns_xfrm,
- flow_cache_gc_work);
-
- INIT_LIST_HEAD(&gc_list);
- spin_lock_bh(&xfrm->flow_cache_gc_lock);
- list_splice_tail_init(&xfrm->flow_cache_gc_list, &gc_list);
- spin_unlock_bh(&xfrm->flow_cache_gc_lock);
-
- list_for_each_entry_safe(fce, n, &gc_list, u.gc_list) {
- flow_entry_kill(fce, xfrm);
- atomic_dec(&xfrm->flow_cache_gc_count);
- }
-}
-
-static void flow_cache_queue_garbage(struct flow_cache_percpu *fcp,
- unsigned int deleted,
- struct list_head *gc_list,
- struct netns_xfrm *xfrm)
-{
- if (deleted) {
- atomic_add(deleted, &xfrm->flow_cache_gc_count);
- fcp->hash_count -= deleted;
- spin_lock_bh(&xfrm->flow_cache_gc_lock);
- list_splice_tail(gc_list, &xfrm->flow_cache_gc_list);
- spin_unlock_bh(&xfrm->flow_cache_gc_lock);
- schedule_work(&xfrm->flow_cache_gc_work);
- }
-}
-
-static void __flow_cache_shrink(struct flow_cache *fc,
- struct flow_cache_percpu *fcp,
- unsigned int shrink_to)
-{
- struct flow_cache_entry *fle;
- struct hlist_node *tmp;
- LIST_HEAD(gc_list);
- unsigned int deleted = 0;
- struct netns_xfrm *xfrm = container_of(fc, struct netns_xfrm,
- flow_cache_global);
- unsigned int i;
-
- for (i = 0; i < flow_cache_hash_size(fc); i++) {
- unsigned int saved = 0;
-
- hlist_for_each_entry_safe(fle, tmp,
- &fcp->hash_table[i], u.hlist) {
- if (saved < shrink_to &&
- flow_entry_valid(fle, xfrm)) {
- saved++;
- } else {
- deleted++;
- hlist_del(&fle->u.hlist);
- list_add_tail(&fle->u.gc_list, &gc_list);
- }
- }
- }
-
- flow_cache_queue_garbage(fcp, deleted, &gc_list, xfrm);
-}
-
-static void flow_cache_shrink(struct flow_cache *fc,
- struct flow_cache_percpu *fcp)
-{
- unsigned int shrink_to = fc->low_watermark / flow_cache_hash_size(fc);
-
- __flow_cache_shrink(fc, fcp, shrink_to);
-}
-
-static void flow_new_hash_rnd(struct flow_cache *fc,
- struct flow_cache_percpu *fcp)
-{
- get_random_bytes(&fcp->hash_rnd, sizeof(u32));
- fcp->hash_rnd_recalc = 0;
- __flow_cache_shrink(fc, fcp, 0);
-}
-
-static u32 flow_hash_code(struct flow_cache *fc,
- struct flow_cache_percpu *fcp,
- const struct flowi *key,
- unsigned int keysize)
-{
- const u32 *k = (const u32 *) key;
- const u32 length = keysize * sizeof(flow_compare_t) / sizeof(u32);
-
- return jhash2(k, length, fcp->hash_rnd)
- & (flow_cache_hash_size(fc) - 1);
-}
-
-/* I hear what you're saying, use memcmp. But memcmp cannot make
- * important assumptions that we can here, such as alignment.
- */
-static int flow_key_compare(const struct flowi *key1, const struct flowi *key2,
- unsigned int keysize)
-{
- const flow_compare_t *k1, *k1_lim, *k2;
-
- k1 = (const flow_compare_t *) key1;
- k1_lim = k1 + keysize;
-
- k2 = (const flow_compare_t *) key2;
-
- do {
- if (*k1++ != *k2++)
- return 1;
- } while (k1 < k1_lim);
-
- return 0;
-}
-
-struct flow_cache_object *
-flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
- flow_resolve_t resolver, void *ctx)
-{
- struct flow_cache *fc = &net->xfrm.flow_cache_global;
- struct flow_cache_percpu *fcp;
- struct flow_cache_entry *fle, *tfle;
- struct flow_cache_object *flo;
- unsigned int keysize;
- unsigned int hash;
-
- local_bh_disable();
- fcp = this_cpu_ptr(fc->percpu);
-
- fle = NULL;
- flo = NULL;
-
- keysize = flow_key_size(family);
- if (!keysize)
- goto nocache;
-
- /* Packet really early in init? Making flow_cache_init a
- * pre-smp initcall would solve this. --RR */
- if (!fcp->hash_table)
- goto nocache;
-
- if (fcp->hash_rnd_recalc)
- flow_new_hash_rnd(fc, fcp);
-
- hash = flow_hash_code(fc, fcp, key, keysize);
- hlist_for_each_entry(tfle, &fcp->hash_table[hash], u.hlist) {
- if (tfle->net == net &&
- tfle->family == family &&
- tfle->dir == dir &&
- flow_key_compare(key, &tfle->key, keysize) == 0) {
- fle = tfle;
- break;
- }
- }
-
- if (unlikely(!fle)) {
- if (fcp->hash_count > fc->high_watermark)
- flow_cache_shrink(fc, fcp);
-
- if (atomic_read(&net->xfrm.flow_cache_gc_count) >
- 2 * num_online_cpus() * fc->high_watermark) {
- flo = ERR_PTR(-ENOBUFS);
- goto ret_object;
- }
-
- fle = kmem_cache_alloc(flow_cachep, GFP_ATOMIC);
- if (fle) {
- fle->net = net;
- fle->family = family;
- fle->dir = dir;
- memcpy(&fle->key, key, keysize * sizeof(flow_compare_t));
- fle->object = NULL;
- hlist_add_head(&fle->u.hlist, &fcp->hash_table[hash]);
- fcp->hash_count++;
- }
- } else if (likely(fle->genid == atomic_read(&net->xfrm.flow_cache_genid))) {
- flo = fle->object;
- if (!flo)
- goto ret_object;
- flo = flo->ops->get(flo);
- if (flo)
- goto ret_object;
- } else if (fle->object) {
- flo = fle->object;
- flo->ops->delete(flo);
- fle->object = NULL;
- }
-
-nocache:
- flo = NULL;
- if (fle) {
- flo = fle->object;
- fle->object = NULL;
- }
- flo = resolver(net, key, family, dir, flo, ctx);
- if (fle) {
- fle->genid = atomic_read(&net->xfrm.flow_cache_genid);
- if (!IS_ERR(flo))
- fle->object = flo;
- else
- fle->genid--;
- } else {
- if (!IS_ERR_OR_NULL(flo))
- flo->ops->delete(flo);
- }
-ret_object:
- local_bh_enable();
- return flo;
-}
-EXPORT_SYMBOL(flow_cache_lookup);
-
-static void flow_cache_flush_tasklet(unsigned long data)
-{
- struct flow_flush_info *info = (void *)data;
- struct flow_cache *fc = info->cache;
- struct flow_cache_percpu *fcp;
- struct flow_cache_entry *fle;
- struct hlist_node *tmp;
- LIST_HEAD(gc_list);
- unsigned int deleted = 0;
- struct netns_xfrm *xfrm = container_of(fc, struct netns_xfrm,
- flow_cache_global);
- unsigned int i;
-
- fcp = this_cpu_ptr(fc->percpu);
- for (i = 0; i < flow_cache_hash_size(fc); i++) {
- hlist_for_each_entry_safe(fle, tmp,
- &fcp->hash_table[i], u.hlist) {
- if (flow_entry_valid(fle, xfrm))
- continue;
-
- deleted++;
- hlist_del(&fle->u.hlist);
- list_add_tail(&fle->u.gc_list, &gc_list);
- }
- }
-
- flow_cache_queue_garbage(fcp, deleted, &gc_list, xfrm);
-
- if (atomic_dec_and_test(&info->cpuleft))
- complete(&info->completion);
-}
-
-/*
- * Return whether a cpu needs flushing. Conservatively, we assume
- * the presence of any entries means the core may require flushing,
- * since the flow_cache_ops.check() function may assume it's running
- * on the same core as the per-cpu cache component.
- */
-static int flow_cache_percpu_empty(struct flow_cache *fc, int cpu)
-{
- struct flow_cache_percpu *fcp;
- unsigned int i;
-
- fcp = per_cpu_ptr(fc->percpu, cpu);
- for (i = 0; i < flow_cache_hash_size(fc); i++)
- if (!hlist_empty(&fcp->hash_table[i]))
- return 0;
- return 1;
-}
-
-static void flow_cache_flush_per_cpu(void *data)
-{
- struct flow_flush_info *info = data;
- struct tasklet_struct *tasklet;
-
- tasklet = &this_cpu_ptr(info->cache->percpu)->flush_tasklet;
- tasklet->data = (unsigned long)info;
- tasklet_schedule(tasklet);
-}
-
-void flow_cache_flush(struct net *net)
-{
- struct flow_flush_info info;
- cpumask_var_t mask;
- int i, self;
-
- /* Track which cpus need flushing to avoid disturbing all cores. */
- if (!alloc_cpumask_var(&mask, GFP_KERNEL))
- return;
- cpumask_clear(mask);
-
- /* Don't want cpus going down or up during this. */
- get_online_cpus();
- mutex_lock(&net->xfrm.flow_flush_sem);
- info.cache = &net->xfrm.flow_cache_global;
- for_each_online_cpu(i)
- if (!flow_cache_percpu_empty(info.cache, i))
- cpumask_set_cpu(i, mask);
- atomic_set(&info.cpuleft, cpumask_weight(mask));
- if (atomic_read(&info.cpuleft) == 0)
- goto done;
-
- init_completion(&info.completion);
-
- local_bh_disable();
- self = cpumask_test_and_clear_cpu(smp_processor_id(), mask);
- on_each_cpu_mask(mask, flow_cache_flush_per_cpu, &info, 0);
- if (self)
- flow_cache_flush_tasklet((unsigned long)&info);
- local_bh_enable();
-
- wait_for_completion(&info.completion);
-
-done:
- mutex_unlock(&net->xfrm.flow_flush_sem);
- put_online_cpus();
- free_cpumask_var(mask);
-}
-
-static void flow_cache_flush_task(struct work_struct *work)
-{
- struct netns_xfrm *xfrm = container_of(work, struct netns_xfrm,
- flow_cache_flush_work);
- struct net *net = container_of(xfrm, struct net, xfrm);
-
- flow_cache_flush(net);
-}
-
-void flow_cache_flush_deferred(struct net *net)
-{
- schedule_work(&net->xfrm.flow_cache_flush_work);
-}
-
-static int flow_cache_cpu_prepare(struct flow_cache *fc, int cpu)
-{
- struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, cpu);
- unsigned int sz = sizeof(struct hlist_head) * flow_cache_hash_size(fc);
-
- if (!fcp->hash_table) {
- fcp->hash_table = kzalloc_node(sz, GFP_KERNEL, cpu_to_node(cpu));
- if (!fcp->hash_table) {
- pr_err("NET: failed to allocate flow cache sz %u\n", sz);
- return -ENOMEM;
- }
- fcp->hash_rnd_recalc = 1;
- fcp->hash_count = 0;
- tasklet_init(&fcp->flush_tasklet, flow_cache_flush_tasklet, 0);
- }
- return 0;
-}
-
-static int flow_cache_cpu_up_prep(unsigned int cpu, struct hlist_node *node)
-{
- struct flow_cache *fc = hlist_entry_safe(node, struct flow_cache, node);
-
- return flow_cache_cpu_prepare(fc, cpu);
-}
-
-static int flow_cache_cpu_dead(unsigned int cpu, struct hlist_node *node)
-{
- struct flow_cache *fc = hlist_entry_safe(node, struct flow_cache, node);
- struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, cpu);
-
- __flow_cache_shrink(fc, fcp, 0);
- return 0;
-}
-
-int flow_cache_init(struct net *net)
-{
- int i;
- struct flow_cache *fc = &net->xfrm.flow_cache_global;
-
- if (!flow_cachep)
- flow_cachep = kmem_cache_create("flow_cache",
- sizeof(struct flow_cache_entry),
- 0, SLAB_PANIC, NULL);
- spin_lock_init(&net->xfrm.flow_cache_gc_lock);
- INIT_LIST_HEAD(&net->xfrm.flow_cache_gc_list);
- INIT_WORK(&net->xfrm.flow_cache_gc_work, flow_cache_gc_task);
- INIT_WORK(&net->xfrm.flow_cache_flush_work, flow_cache_flush_task);
- mutex_init(&net->xfrm.flow_flush_sem);
- atomic_set(&net->xfrm.flow_cache_gc_count, 0);
-
- fc->hash_shift = 10;
- fc->low_watermark = 2 * flow_cache_hash_size(fc);
- fc->high_watermark = 4 * flow_cache_hash_size(fc);
-
- fc->percpu = alloc_percpu(struct flow_cache_percpu);
- if (!fc->percpu)
- return -ENOMEM;
-
- if (cpuhp_state_add_instance(CPUHP_NET_FLOW_PREPARE, &fc->node))
- goto err;
-
- setup_timer(&fc->rnd_timer, flow_cache_new_hashrnd,
- (unsigned long) fc);
- fc->rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;
- add_timer(&fc->rnd_timer);
-
- return 0;
-
-err:
- for_each_possible_cpu(i) {
- struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, i);
- kfree(fcp->hash_table);
- fcp->hash_table = NULL;
- }
-
- free_percpu(fc->percpu);
- fc->percpu = NULL;
-
- return -ENOMEM;
-}
-EXPORT_SYMBOL(flow_cache_init);
-
-void flow_cache_fini(struct net *net)
-{
- int i;
- struct flow_cache *fc = &net->xfrm.flow_cache_global;
-
- del_timer_sync(&fc->rnd_timer);
-
- cpuhp_state_remove_instance_nocalls(CPUHP_NET_FLOW_PREPARE, &fc->node);
-
- for_each_possible_cpu(i) {
- struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, i);
- kfree(fcp->hash_table);
- fcp->hash_table = NULL;
- }
-
- free_percpu(fc->percpu);
- fc->percpu = NULL;
-}
-EXPORT_SYMBOL(flow_cache_fini);
-
-void __init flow_cache_hp_init(void)
-{
- int ret;
-
- ret = cpuhp_setup_state_multi(CPUHP_NET_FLOW_PREPARE,
- "net/flow:prepare",
- flow_cache_cpu_up_prep,
- flow_cache_cpu_dead);
- WARN_ON(ret < 0);
-}
xfrm_pol_put(xp);
}
-static struct flow_cache_object *xfrm_policy_flo_get(struct flow_cache_object *flo)
-{
- struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
-
- if (unlikely(pol->walk.dead))
- flo = NULL;
- else
- xfrm_pol_hold(pol);
-
- return flo;
-}
-
-static int xfrm_policy_flo_check(struct flow_cache_object *flo)
-{
- struct xfrm_policy *pol = container_of(flo, struct xfrm_policy, flo);
-
- return !pol->walk.dead;
-}
-
-static void xfrm_policy_flo_delete(struct flow_cache_object *flo)
-{
- xfrm_pol_put(container_of(flo, struct xfrm_policy, flo));
-}
-
-static const struct flow_cache_ops xfrm_policy_fc_ops = {
- .get = xfrm_policy_flo_get,
- .check = xfrm_policy_flo_check,
- .delete = xfrm_policy_flo_delete,
-};
-
/* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2
* SPD calls.
*/
(unsigned long)policy);
setup_timer(&policy->polq.hold_timer, xfrm_policy_queue_process,
(unsigned long)policy);
- policy->flo.ops = &xfrm_policy_fc_ops;
}
return policy;
}
else
hlist_add_head(&policy->bydst, chain);
__xfrm_policy_link(policy, dir);
- atomic_inc(&net->xfrm.flow_cache_genid);
/* After previous checking, family can either be AF_INET or AF_INET6 */
if (policy->family == AF_INET)
return tos;
}
-static struct flow_cache_object *xfrm_bundle_flo_get(struct flow_cache_object *flo)
-{
- struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
- struct dst_entry *dst = &xdst->u.dst;
-
- if (xdst->route == NULL) {
- /* Dummy bundle - if it has xfrms we were not
- * able to build bundle as template resolution failed.
- * It means we need to try again resolving. */
- if (xdst->num_xfrms > 0)
- return NULL;
- } else if (dst->flags & DST_XFRM_QUEUE) {
- return NULL;
- } else {
- /* Real bundle */
- if (stale_bundle(dst))
- return NULL;
- }
-
- dst_hold(dst);
- return flo;
-}
-
-static int xfrm_bundle_flo_check(struct flow_cache_object *flo)
-{
- struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
- struct dst_entry *dst = &xdst->u.dst;
-
- if (!xdst->route)
- return 0;
- if (stale_bundle(dst))
- return 0;
-
- return 1;
-}
-
-static void xfrm_bundle_flo_delete(struct flow_cache_object *flo)
-{
- struct xfrm_dst *xdst = container_of(flo, struct xfrm_dst, flo);
- struct dst_entry *dst = &xdst->u.dst;
-
- /* Mark DST_OBSOLETE_DEAD to fail the next xfrm_dst_check() */
- dst->obsolete = DST_OBSOLETE_DEAD;
- dst_release_immediate(dst);
-}
-
-static const struct flow_cache_ops xfrm_bundle_fc_ops = {
- .get = xfrm_bundle_flo_get,
- .check = xfrm_bundle_flo_check,
- .delete = xfrm_bundle_flo_delete,
-};
-
static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
{
const struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
struct dst_entry *dst = &xdst->u.dst;
memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
- xdst->flo.ops = &xfrm_bundle_fc_ops;
} else
xdst = ERR_PTR(-ENOBUFS);
* notice. That's what we are validating here via the
* stale_bundle() check.
*
- * When an xdst is removed from flow cache, DST_OBSOLETE_DEAD will
- * be marked on it.
* When a dst is removed from the fib tree, DST_OBSOLETE_DEAD will
* be marked on it.
- * Both will force stable_bundle() to fail on any xdst bundle with
+ * This will force stale_bundle() to fail on any xdst bundle with
* this dst linked in it.
*/
if (dst->obsolete < 0 && !stale_bundle(dst))
return dst;
}
-void xfrm_garbage_collect(struct net *net)
-{
- flow_cache_flush(net);
-}
-EXPORT_SYMBOL(xfrm_garbage_collect);
-
-void xfrm_garbage_collect_deferred(struct net *net)
-{
- flow_cache_flush_deferred(net);
-}
-EXPORT_SYMBOL(xfrm_garbage_collect_deferred);
-
static void xfrm_init_pmtu(struct dst_entry *dst)
{
do {
rv = xfrm_sysctl_init(net);
if (rv < 0)
goto out_sysctl;
- rv = flow_cache_init(net);
- if (rv < 0)
- goto out;
return 0;
-out:
- xfrm_sysctl_fini(net);
out_sysctl:
xfrm_policy_fini(net);
out_policy:
static void __net_exit xfrm_net_exit(struct net *net)
{
- flow_cache_fini(net);
xfrm_sysctl_fini(net);
xfrm_policy_fini(net);
xfrm_state_fini(net);
void __init xfrm_init(void)
{
- flow_cache_hp_init();
register_pernet_subsys(&xfrm_net_ops);
seqcount_init(&xfrm_policy_hash_generation);
xfrm_input_init();
projects / linux-2.6-microblaze.git / commitdiff