X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=net%2Fipv4%2Finet_fragment.c;h=e15e04fc66615dc354241214fdadaa366512264f;hb=0e4bd10c9b7e9ed65132f5935328275deb760384;hp=69623ff4e4c632380442023bfaac791a6f381251;hpb=7eb95156d9dce2f59794264db336ce007d71638b;p=linux-2.6-omap-h63xx.git

diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 69623ff4e4c..e15e04fc666 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -16,9 +16,40 @@
 #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;
@@ -35,10 +66,196 @@ void inet_frags_init(struct inet_frags *f)
 	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);