1 files changed, 68 insertions, 0 deletions
diff --git a/include/net/inetpeer.h b/include/net/inetpeer.h
new file mode 100644
index 00000000..417d0c89
--- /dev/null
+++ b/include/net/inetpeer.h
@@ -0,0 +1,68 @@
+/*
+ *		INETPEER - A storage for permanent information about peers
+ *
+ *  Authors:	Andrey V. Savochkin <saw@msu.ru>
+ */
+
+#ifndef _NET_INETPEER_H
+#define _NET_INETPEER_H
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/spinlock.h>
+#include <asm/atomic.h>
+
+struct inet_peer {
+	/* group together avl_left,avl_right,v4daddr to speedup lookups */
+	struct inet_peer	*avl_left, *avl_right;
+	__be32			v4daddr;	/* peer's address */
+	__u32			avl_height;
+	struct list_head	unused;
+	__u32			dtime;		/* the time of last use of not
+						 * referenced entries */
+	atomic_t		refcnt;
+	/*
+	 * Once inet_peer is queued for deletion (refcnt == -1), following fields
+	 * are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp
+	 * We can share memory with rcu_head to keep inet_peer small
+	 * (less then 64 bytes)
+	 */
+	union {
+		struct {
+			atomic_t	rid;		/* Frag reception counter */
+			atomic_t	ip_id_count;	/* IP ID for the next packet */
+			__u32		tcp_ts;
+			__u32		tcp_ts_stamp;
+		};
+		struct rcu_head         rcu;
+	};
+};
+
+void			inet_initpeers(void) __init;
+
+/* can be called with or without local BH being disabled */
+struct inet_peer	*inet_getpeer(__be32 daddr, int create);
+
+/* can be called from BH context or outside */
+extern void inet_putpeer(struct inet_peer *p);
+
+/*
+ * temporary check to make sure we dont access rid, ip_id_count, tcp_ts,
+ * tcp_ts_stamp if no refcount is taken on inet_peer
+ */
+static inline void inet_peer_refcheck(const struct inet_peer *p)
+{
+	WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0);
+}
+
+
+/* can be called with or without local BH being disabled */
+static inline __u16	inet_getid(struct inet_peer *p, int more)
+{
+	more++;
+	inet_peer_refcheck(p);
+	return atomic_add_return(more, &p->ip_id_count) - more;
+}
+
+#endif /* _NET_INETPEER_H */