1 files changed, 55 insertions, 0 deletions
diff --git a/net/ipv4/multipath.c b/net/ipv4/multipath.c
new file mode 100644
index 00000000000..4e9ca7c7640
--- /dev/null
+++ b/net/ipv4/multipath.c
@@ -0,0 +1,55 @@
+/* multipath.c: IPV4 multipath algorithm support.
+ *
+ * Copyright (C) 2004, 2005 Einar Lueck <elueck@de.ibm.com>
+ * Copyright (C) 2005 David S. Miller <davem@davemloft.net>
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/spinlock.h>
+
+#include <net/ip_mp_alg.h>
+
+static DEFINE_SPINLOCK(alg_table_lock);
+struct ip_mp_alg_ops *ip_mp_alg_table[IP_MP_ALG_MAX + 1];
+
+int multipath_alg_register(struct ip_mp_alg_ops *ops, enum ip_mp_alg n)
+{
+	struct ip_mp_alg_ops **slot;
+	int err;
+
+	if (n < IP_MP_ALG_NONE || n > IP_MP_ALG_MAX ||
+	    !ops->mp_alg_select_route)
+		return -EINVAL;
+
+	spin_lock(&alg_table_lock);
+	slot = &ip_mp_alg_table[n];
+	if (*slot != NULL) {
+		err = -EBUSY;
+	} else {
+		*slot = ops;
+		err = 0;
+	}
+	spin_unlock(&alg_table_lock);
+
+	return err;
+}
+EXPORT_SYMBOL(multipath_alg_register);
+
+void multipath_alg_unregister(struct ip_mp_alg_ops *ops, enum ip_mp_alg n)
+{
+	struct ip_mp_alg_ops **slot;
+
+	if (n < IP_MP_ALG_NONE || n > IP_MP_ALG_MAX)
+		return;
+
+	spin_lock(&alg_table_lock);
+	slot = &ip_mp_alg_table[n];
+	if (*slot == ops)
+		*slot = NULL;
+	spin_unlock(&alg_table_lock);
+
+	synchronize_net();
+}
+EXPORT_SYMBOL(multipath_alg_unregister);