#include <linux/module.h>
#include <linux/timer.h>
#include <linux/mm.h>
+#include <linux/random.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
#include <net/inet_frag.h>
+static void inet_frag_secret_rebuild(unsigned long dummy)
+{
+ struct inet_frags *f = (struct inet_frags *)dummy;
+ unsigned long now = jiffies;
+ int i;
+
+ write_lock(&f->lock);
+ get_random_bytes(&f->rnd, sizeof(u32));
+ for (i = 0; i < INETFRAGS_HASHSZ; i++) {
+ struct inet_frag_queue *q;
+ struct hlist_node *p, *n;
+
+ hlist_for_each_entry_safe(q, p, n, &f->hash[i], list) {
+ unsigned int hval = f->hashfn(q);
+
+ if (hval != i) {
+ hlist_del(&q->list);
+
+ /* Relink to new hash chain. */
+ hlist_add_head(&q->list, &f->hash[hval]);
+ }
+ }
+ }
+ write_unlock(&f->lock);
+
+ mod_timer(&f->secret_timer, now + f->secret_interval);
+}
+
void inet_frags_init(struct inet_frags *f)
{
int i;
for (i = 0; i < INETFRAGS_HASHSZ; i++)
INIT_HLIST_HEAD(&f->hash[i]);
- INIT_LIST_HEAD(&f->lru_list);
rwlock_init(&f->lock);
f->rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^
(jiffies ^ (jiffies >> 6)));
- f->nqueues = 0;
- atomic_set(&f->mem, 0);
-
+ setup_timer(&f->secret_timer, inet_frag_secret_rebuild,
+ (unsigned long)f);
+ f->secret_timer.expires = jiffies + f->secret_interval;
+ add_timer(&f->secret_timer);
}
EXPORT_SYMBOL(inet_frags_init);
+void inet_frags_init_net(struct netns_frags *nf)
+{
+ nf->nqueues = 0;
+ atomic_set(&nf->mem, 0);
+ INIT_LIST_HEAD(&nf->lru_list);
+}
+EXPORT_SYMBOL(inet_frags_init_net);
+
void inet_frags_fini(struct inet_frags *f)
{
+ del_timer(&f->secret_timer);
}
EXPORT_SYMBOL(inet_frags_fini);
+void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f)
+{
+ nf->low_thresh = 0;
+
+ local_bh_disable();
+ inet_frag_evictor(nf, f);
+ local_bh_enable();
+}
+EXPORT_SYMBOL(inet_frags_exit_net);
+
static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f)
{
write_lock(&f->lock);
hlist_del(&fq->list);
list_del(&fq->lru_list);
- f->nqueues--;
+ fq->net->nqueues--;
write_unlock(&f->lock);
}
if (del_timer(&fq->timer))
atomic_dec(&fq->refcnt);
- if (!(fq->last_in & COMPLETE)) {
+ if (!(fq->last_in & INET_FRAG_COMPLETE)) {
fq_unlink(fq, f);
atomic_dec(&fq->refcnt);
- fq->last_in |= COMPLETE;
+ fq->last_in |= INET_FRAG_COMPLETE;
}
}
EXPORT_SYMBOL(inet_frag_kill);
+
+static inline void frag_kfree_skb(struct netns_frags *nf, struct inet_frags *f,
+ struct sk_buff *skb, int *work)
+{
+ if (work)
+ *work -= skb->truesize;
+
+ atomic_sub(skb->truesize, &nf->mem);
+ if (f->skb_free)
+ f->skb_free(skb);
+ kfree_skb(skb);
+}
+
+void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f,
+ int *work)
+{
+ struct sk_buff *fp;
+ struct netns_frags *nf;
+
+ WARN_ON(!(q->last_in & INET_FRAG_COMPLETE));
+ WARN_ON(del_timer(&q->timer) != 0);
+
+ /* Release all fragment data. */
+ fp = q->fragments;
+ nf = q->net;
+ while (fp) {
+ struct sk_buff *xp = fp->next;
+
+ frag_kfree_skb(nf, f, fp, work);
+ fp = xp;
+ }
+
+ if (work)
+ *work -= f->qsize;
+ atomic_sub(f->qsize, &nf->mem);
+
+ if (f->destructor)
+ f->destructor(q);
+ kfree(q);
+
+}
+EXPORT_SYMBOL(inet_frag_destroy);
+
+int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f)
+{
+ struct inet_frag_queue *q;
+ int work, evicted = 0;
+
+ work = atomic_read(&nf->mem) - nf->low_thresh;
+ while (work > 0) {
+ read_lock(&f->lock);
+ if (list_empty(&nf->lru_list)) {
+ read_unlock(&f->lock);
+ break;
+ }
+
+ q = list_first_entry(&nf->lru_list,
+ struct inet_frag_queue, lru_list);
+ atomic_inc(&q->refcnt);
+ read_unlock(&f->lock);
+
+ spin_lock(&q->lock);
+ if (!(q->last_in & INET_FRAG_COMPLETE))
+ inet_frag_kill(q, f);
+ spin_unlock(&q->lock);
+
+ if (atomic_dec_and_test(&q->refcnt))
+ inet_frag_destroy(q, f, &work);
+ evicted++;
+ }
+
+ return evicted;
+}
+EXPORT_SYMBOL(inet_frag_evictor);
+
+static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf,
+ struct inet_frag_queue *qp_in, struct inet_frags *f,
+ void *arg)
+{
+ struct inet_frag_queue *qp;
+#ifdef CONFIG_SMP
+ struct hlist_node *n;
+#endif
+ unsigned int hash;
+
+ write_lock(&f->lock);
+ /*
+ * While we stayed w/o the lock other CPU could update
+ * the rnd seed, so we need to re-calculate the hash
+ * chain. Fortunatelly the qp_in can be used to get one.
+ */
+ hash = f->hashfn(qp_in);
+#ifdef CONFIG_SMP
+ /* With SMP race we have to recheck hash table, because
+ * such entry could be created on other cpu, while we
+ * promoted read lock to write lock.
+ */
+ hlist_for_each_entry(qp, n, &f->hash[hash], list) {
+ if (qp->net == nf && f->match(qp, arg)) {
+ atomic_inc(&qp->refcnt);
+ write_unlock(&f->lock);
+ qp_in->last_in |= INET_FRAG_COMPLETE;
+ inet_frag_put(qp_in, f);
+ return qp;
+ }
+ }
+#endif
+ qp = qp_in;
+ if (!mod_timer(&qp->timer, jiffies + nf->timeout))
+ atomic_inc(&qp->refcnt);
+
+ atomic_inc(&qp->refcnt);
+ hlist_add_head(&qp->list, &f->hash[hash]);
+ list_add_tail(&qp->lru_list, &nf->lru_list);
+ nf->nqueues++;
+ write_unlock(&f->lock);
+ return qp;
+}
+
+static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
+ struct inet_frags *f, void *arg)
+{
+ struct inet_frag_queue *q;
+
+ q = kzalloc(f->qsize, GFP_ATOMIC);
+ if (q == NULL)
+ return NULL;
+
+ f->constructor(q, arg);
+ atomic_add(f->qsize, &nf->mem);
+ setup_timer(&q->timer, f->frag_expire, (unsigned long)q);
+ spin_lock_init(&q->lock);
+ atomic_set(&q->refcnt, 1);
+ q->net = nf;
+
+ return q;
+}
+
+static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf,
+ struct inet_frags *f, void *arg)
+{
+ struct inet_frag_queue *q;
+
+ q = inet_frag_alloc(nf, f, arg);
+ if (q == NULL)
+ return NULL;
+
+ return inet_frag_intern(nf, q, f, arg);
+}
+
+struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
+ struct inet_frags *f, void *key, unsigned int hash)
+ __releases(&f->lock)
+{
+ struct inet_frag_queue *q;
+ struct hlist_node *n;
+
+ hlist_for_each_entry(q, n, &f->hash[hash], list) {
+ if (q->net == nf && f->match(q, key)) {
+ atomic_inc(&q->refcnt);
+ read_unlock(&f->lock);
+ return q;
+ }
+ }
+ read_unlock(&f->lock);
+
+ return inet_frag_create(nf, f, key);
+}
+EXPORT_SYMBOL(inet_frag_find);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff