#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->ctl->secret_interval);
+}
+
void inet_frags_init(struct inet_frags *f)
{
int i;
f->nqueues = 0;
atomic_set(&f->mem, 0);
+ init_timer(&f->secret_timer);
+ f->secret_timer.function = inet_frag_secret_rebuild;
+ f->secret_timer.data = (unsigned long)f;
+ f->secret_timer.expires = jiffies + f->ctl->secret_interval;
+ add_timer(&f->secret_timer);
}
EXPORT_SYMBOL(inet_frags_init);
void inet_frags_fini(struct inet_frags *f)
{
+ del_timer(&f->secret_timer);
}
EXPORT_SYMBOL(inet_frags_fini);
+
+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--;
+ write_unlock(&f->lock);
+}
+
+void inet_frag_kill(struct inet_frag_queue *fq, struct inet_frags *f)
+{
+ if (del_timer(&fq->timer))
+ atomic_dec(&fq->refcnt);
+
+ if (!(fq->last_in & COMPLETE)) {
+ fq_unlink(fq, f);
+ atomic_dec(&fq->refcnt);
+ fq->last_in |= COMPLETE;
+ }
+}
+
+EXPORT_SYMBOL(inet_frag_kill);
+
+static inline void frag_kfree_skb(struct inet_frags *f, struct sk_buff *skb,
+ int *work)
+{
+ if (work)
+ *work -= skb->truesize;
+
+ atomic_sub(skb->truesize, &f->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;
+
+ BUG_TRAP(q->last_in & COMPLETE);
+ BUG_TRAP(del_timer(&q->timer) == 0);
+
+ /* Release all fragment data. */
+ fp = q->fragments;
+ while (fp) {
+ struct sk_buff *xp = fp->next;
+
+ frag_kfree_skb(f, fp, work);
+ fp = xp;
+ }
+
+ if (work)
+ *work -= f->qsize;
+ atomic_sub(f->qsize, &f->mem);
+
+ if (f->destructor)
+ f->destructor(q);
+ kfree(q);
+
+}
+EXPORT_SYMBOL(inet_frag_destroy);
+
+int inet_frag_evictor(struct inet_frags *f)
+{
+ struct inet_frag_queue *q;
+ int work, evicted = 0;
+
+ work = atomic_read(&f->mem) - f->ctl->low_thresh;
+ while (work > 0) {
+ read_lock(&f->lock);
+ if (list_empty(&f->lru_list)) {
+ read_unlock(&f->lock);
+ break;
+ }
+
+ q = list_first_entry(&f->lru_list,
+ struct inet_frag_queue, lru_list);
+ atomic_inc(&q->refcnt);
+ read_unlock(&f->lock);
+
+ spin_lock(&q->lock);
+ if (!(q->last_in & 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 inet_frag_queue *qp_in,
+ struct inet_frags *f, unsigned int hash, void *arg)
+{
+ struct inet_frag_queue *qp;
+#ifdef CONFIG_SMP
+ struct hlist_node *n;
+#endif
+
+ write_lock(&f->lock);
+#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 (f->match(qp, arg)) {
+ atomic_inc(&qp->refcnt);
+ write_unlock(&f->lock);
+ qp_in->last_in |= COMPLETE;
+ inet_frag_put(qp_in, f);
+ return qp;
+ }
+ }
+#endif
+ qp = qp_in;
+ if (!mod_timer(&qp->timer, jiffies + f->ctl->timeout))
+ atomic_inc(&qp->refcnt);
+
+ atomic_inc(&qp->refcnt);
+ hlist_add_head(&qp->list, &f->hash[hash]);
+ list_add_tail(&qp->lru_list, &f->lru_list);
+ f->nqueues++;
+ write_unlock(&f->lock);
+ return qp;
+}
+
+static struct inet_frag_queue *inet_frag_alloc(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, &f->mem);
+ setup_timer(&q->timer, f->frag_expire, (unsigned long)q);
+ spin_lock_init(&q->lock);
+ atomic_set(&q->refcnt, 1);
+
+ return q;
+}
+
+static struct inet_frag_queue *inet_frag_create(struct inet_frags *f,
+ void *arg, unsigned int hash)
+{
+ struct inet_frag_queue *q;
+
+ q = inet_frag_alloc(f, arg);
+ if (q == NULL)
+ return NULL;
+
+ return inet_frag_intern(q, f, hash, arg);
+}
+
+struct inet_frag_queue *inet_frag_find(struct inet_frags *f, void *key,
+ unsigned int hash)
+{
+ struct inet_frag_queue *q;
+ struct hlist_node *n;
+
+ read_lock(&f->lock);
+ hlist_for_each_entry(q, n, &f->hash[hash], list) {
+ if (f->match(q, key)) {
+ atomic_inc(&q->refcnt);
+ read_unlock(&f->lock);
+ return q;
+ }
+ }
+ read_unlock(&f->lock);
+
+ return inet_frag_create(f, key, hash);
+}
+EXPORT_SYMBOL(inet_frag_find);
projects / linux-2.6-omap-h63xx.git / blobdiff