1 files changed, 144 insertions, 0 deletions
diff --git a/net/ipv4/xfrm4_tunnel.c b/net/ipv4/xfrm4_tunnel.c
new file mode 100644
index 0000000..413191f
--- /dev/null
+++ b/net/ipv4/xfrm4_tunnel.c
@@ -0,0 +1,144 @@
+/* xfrm4_tunnel.c: Generic IP tunnel transformer.
+ *
+ * Copyright (C) 2003 David S. Miller (davem@redhat.com)
+ */
+
+#include <linux/skbuff.h>
+#include <linux/module.h>
+#include <net/xfrm.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+
+static int ipip_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct iphdr *iph;
+	
+	iph = skb->nh.iph;
+	iph->tot_len = htons(skb->len);
+	ip_send_check(iph);
+
+	return 0;
+}
+
+static int ipip_xfrm_rcv(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
+{
+	return 0;
+}
+
+static struct xfrm_tunnel *ipip_handler;
+static DECLARE_MUTEX(xfrm4_tunnel_sem);
+
+int xfrm4_tunnel_register(struct xfrm_tunnel *handler)
+{
+	int ret;
+
+	down(&xfrm4_tunnel_sem);
+	ret = 0;
+	if (ipip_handler != NULL)
+		ret = -EINVAL;
+	if (!ret)
+		ipip_handler = handler;
+	up(&xfrm4_tunnel_sem);
+
+	return ret;
+}
+
+EXPORT_SYMBOL(xfrm4_tunnel_register);
+
+int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler)
+{
+	int ret;
+
+	down(&xfrm4_tunnel_sem);
+	ret = 0;
+	if (ipip_handler != handler)
+		ret = -EINVAL;
+	if (!ret)
+		ipip_handler = NULL;
+	up(&xfrm4_tunnel_sem);
+
+	synchronize_net();
+
+	return ret;
+}
+
+EXPORT_SYMBOL(xfrm4_tunnel_deregister);
+
+static int ipip_rcv(struct sk_buff *skb)
+{
+	struct xfrm_tunnel *handler = ipip_handler;
+
+	/* Tunnel devices take precedence.  */
+	if (handler && handler->handler(skb) == 0)
+		return 0;
+
+	return xfrm4_rcv(skb);
+}
+
+static void ipip_err(struct sk_buff *skb, u32 info)
+{
+	struct xfrm_tunnel *handler = ipip_handler;
+	u32 arg = info;
+
+	if (handler)
+		handler->err_handler(skb, &arg);
+}
+
+static int ipip_init_state(struct xfrm_state *x, void *args)
+{
+	if (!x->props.mode)
+		return -EINVAL;
+
+	if (x->encap)
+		return -EINVAL;
+
+	x->props.header_len = sizeof(struct iphdr);
+
+	return 0;
+}
+
+static void ipip_destroy(struct xfrm_state *x)
+{
+}
+
+static struct xfrm_type ipip_type = {
+	.description	= "IPIP",
+	.owner		= THIS_MODULE,
+	.proto	     	= IPPROTO_IPIP,
+	.init_state	= ipip_init_state,
+	.destructor	= ipip_destroy,
+	.input		= ipip_xfrm_rcv,
+	.output		= ipip_output
+};
+
+static struct net_protocol ipip_protocol = {
+	.handler	=	ipip_rcv,
+	.err_handler	=	ipip_err,
+	.no_policy	=	1,
+};
+
+static int __init ipip_init(void)
+{
+	if (xfrm_register_type(&ipip_type, AF_INET) < 0) {
+		printk(KERN_INFO "ipip init: can't add xfrm type\n");
+		return -EAGAIN;
+	}
+	if (inet_add_protocol(&ipip_protocol, IPPROTO_IPIP) < 0) {
+		printk(KERN_INFO "ipip init: can't add protocol\n");
+		xfrm_unregister_type(&ipip_type, AF_INET);
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+static void __exit ipip_fini(void)
+{
+	if (inet_del_protocol(&ipip_protocol, IPPROTO_IPIP) < 0)
+		printk(KERN_INFO "ipip close: can't remove protocol\n");
+	if (xfrm_unregister_type(&ipip_type, AF_INET) < 0)
+		printk(KERN_INFO "ipip close: can't remove xfrm type\n");
+}
+
+module_init(ipip_init);
+module_exit(ipip_fini);
+MODULE_LICENSE("GPL");