#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/net.h>
+#include <linux/workqueue.h>
#include <net/ip.h>
#include <net/inetpeer.h>
#include <net/secure_seq.h>
* Theory of operations.
* We keep one entry for each peer IP address. The nodes contains long-living
* information about the peer which doesn't depend on routes.
- * At this moment this information consists only of ID field for the next
- * outgoing IP packet. This field is incremented with each packet as encoded
- * in inet_getid() function (include/net/inetpeer.h).
- * At the moment of writing this notes identifier of IP packets is generated
- * to be unpredictable using this code only for packets subjected
- * (actually or potentially) to defragmentation. I.e. DF packets less than
- * PMTU in size uses a constant ID and do not use this code (see
- * ip_select_ident() in include/net/ip.h).
*
- * Route cache entries hold references to our nodes.
- * New cache entries get references via lookup by destination IP address in
- * the avl tree. The reference is grabbed only when it's needed i.e. only
- * when we try to output IP packet which needs an unpredictable ID (see
- * __ip_select_ident() in net/ipv4/route.c).
* Nodes are removed only when reference counter goes to 0.
* When it's happened the node may be removed when a sufficient amount of
* time has been passed since its last use. The less-recently-used entry can
* refcnt: atomically against modifications on other CPU;
* usually under some other lock to prevent node disappearing
* daddr: unchangeable
- * ip_id_count: atomic value (no lock needed)
*/
static struct kmem_cache *peer_cachep __read_mostly;
+static LIST_HEAD(gc_list);
+static const int gc_delay = 60 * HZ;
+static struct delayed_work gc_work;
+static DEFINE_SPINLOCK(gc_lock);
+
#define node_height(x) x->avl_height
#define peer_avl_empty ((struct inet_peer *)&peer_fake_node)
int inet_peer_minttl __read_mostly = 120 * HZ; /* TTL under high load: 120 sec */
int inet_peer_maxttl __read_mostly = 10 * 60 * HZ; /* usual time to live: 10 min */
+static void inetpeer_gc_worker(struct work_struct *work)
+{
+ struct inet_peer *p, *n;
+ LIST_HEAD(list);
+
+ spin_lock_bh(&gc_lock);
+ list_replace_init(&gc_list, &list);
+ spin_unlock_bh(&gc_lock);
+
+ if (list_empty(&list))
+ return;
+
+ list_for_each_entry_safe(p, n, &list, gc_list) {
+
+ if(need_resched())
+ cond_resched();
+
+ if (p->avl_left != peer_avl_empty) {
+ list_add_tail(&p->avl_left->gc_list, &list);
+ p->avl_left = peer_avl_empty;
+ }
+
+ if (p->avl_right != peer_avl_empty) {
+ list_add_tail(&p->avl_right->gc_list, &list);
+ p->avl_right = peer_avl_empty;
+ }
+
+ n = list_entry(p->gc_list.next, struct inet_peer, gc_list);
+
+ if (!atomic_read(&p->refcnt)) {
+ list_del(&p->gc_list);
+ kmem_cache_free(peer_cachep, p);
+ }
+ }
+
+ if (list_empty(&list))
+ return;
+
+ spin_lock_bh(&gc_lock);
+ list_splice(&list, &gc_list);
+ spin_unlock_bh(&gc_lock);
+
+ schedule_delayed_work(&gc_work, gc_delay);
+}
/* Called from ip_output.c:ip_init */
void __init inet_initpeers(void)
0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
NULL);
+ INIT_DELAYED_WORK_DEFERRABLE(&gc_work, inetpeer_gc_worker);
}
static int addr_compare(const struct inetpeer_addr *a,
p->daddr = *daddr;
atomic_set(&p->refcnt, 1);
atomic_set(&p->rid, 0);
- atomic_set(&p->ip_id_count,
- (daddr->family == AF_INET) ?
- secure_ip_id(daddr->addr.a4) :
- secure_ipv6_id(daddr->addr.a6));
p->tcp_ts_stamp = 0;
p->metrics[RTAX_LOCK-1] = INETPEER_METRICS_NEW;
p->rate_tokens = 0;
p->pmtu_expires = 0;
p->pmtu_orig = 0;
memset(&p->redirect_learned, 0, sizeof(p->redirect_learned));
-
+ INIT_LIST_HEAD(&p->gc_list);
/* Link the node. */
link_to_pool(p, base);
return rc;
}
EXPORT_SYMBOL(inet_peer_xrlim_allow);
+
+static void inetpeer_inval_rcu(struct rcu_head *head)
+{
+ struct inet_peer *p = container_of(head, struct inet_peer, gc_rcu);
+
+ spin_lock_bh(&gc_lock);
+ list_add_tail(&p->gc_list, &gc_list);
+ spin_unlock_bh(&gc_lock);
+
+ schedule_delayed_work(&gc_work, gc_delay);
+}
+
+void inetpeer_invalidate_tree(int family)
+{
+ struct inet_peer *old, *new, *prev;
+ struct inet_peer_base *base = family_to_base(family);
+
+ write_seqlock_bh(&base->lock);
+
+ old = base->root;
+ if (old == peer_avl_empty_rcu)
+ goto out;
+
+ new = peer_avl_empty_rcu;
+
+ prev = cmpxchg(&base->root, old, new);
+ if (prev == old) {
+ base->total = 0;
+ call_rcu(&prev->gc_rcu, inetpeer_inval_rcu);
+ }
+
+out:
+ write_sequnlock_bh(&base->lock);
+}
+EXPORT_SYMBOL(inetpeer_invalidate_tree);
git.openpandora.org / pandora-kernel.git / blobdiff