1 files changed, 305 insertions, 0 deletions
diff --git a/net/ipv6/tunnel6.c b/net/ipv6/tunnel6.c
new file mode 100644
index 000000000..00e8d8b1c
--- /dev/null
+++ b/net/ipv6/tunnel6.c
@@ -0,0 +1,305 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C)2003,2004 USAGI/WIDE Project
+ *
+ * Authors	Mitsuru KANDA  <mk@linux-ipv6.org>
+ *		YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
+ */
+
+#define pr_fmt(fmt) "IPv6: " fmt
+
+#include <linux/icmpv6.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/xfrm.h>
+
+static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly;
+static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly;
+static struct xfrm6_tunnel __rcu *tunnelmpls6_handlers __read_mostly;
+static DEFINE_MUTEX(tunnel6_mutex);
+
+static inline int xfrm6_tunnel_mpls_supported(void)
+{
+	return IS_ENABLED(CONFIG_MPLS);
+}
+
+int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
+{
+	struct xfrm6_tunnel __rcu **pprev;
+	struct xfrm6_tunnel *t;
+	int ret = -EEXIST;
+	int priority = handler->priority;
+
+	mutex_lock(&tunnel6_mutex);
+
+	switch (family) {
+	case AF_INET6:
+		pprev = &tunnel6_handlers;
+		break;
+	case AF_INET:
+		pprev = &tunnel46_handlers;
+		break;
+	case AF_MPLS:
+		pprev = &tunnelmpls6_handlers;
+		break;
+	default:
+		goto err;
+	}
+
+	for (; (t = rcu_dereference_protected(*pprev,
+			lockdep_is_held(&tunnel6_mutex))) != NULL;
+	     pprev = &t->next) {
+		if (t->priority > priority)
+			break;
+		if (t->priority == priority)
+			goto err;
+	}
+
+	handler->next = *pprev;
+	rcu_assign_pointer(*pprev, handler);
+
+	ret = 0;
+
+err:
+	mutex_unlock(&tunnel6_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL(xfrm6_tunnel_register);
+
+int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
+{
+	struct xfrm6_tunnel __rcu **pprev;
+	struct xfrm6_tunnel *t;
+	int ret = -ENOENT;
+
+	mutex_lock(&tunnel6_mutex);
+
+	switch (family) {
+	case AF_INET6:
+		pprev = &tunnel6_handlers;
+		break;
+	case AF_INET:
+		pprev = &tunnel46_handlers;
+		break;
+	case AF_MPLS:
+		pprev = &tunnelmpls6_handlers;
+		break;
+	default:
+		goto err;
+	}
+
+	for (; (t = rcu_dereference_protected(*pprev,
+			lockdep_is_held(&tunnel6_mutex))) != NULL;
+	     pprev = &t->next) {
+		if (t == handler) {
+			*pprev = handler->next;
+			ret = 0;
+			break;
+		}
+	}
+
+err:
+	mutex_unlock(&tunnel6_mutex);
+
+	synchronize_net();
+
+	return ret;
+}
+EXPORT_SYMBOL(xfrm6_tunnel_deregister);
+
+#define for_each_tunnel_rcu(head, handler)		\
+	for (handler = rcu_dereference(head);		\
+	     handler != NULL;				\
+	     handler = rcu_dereference(handler->next))	\
+
+static int tunnelmpls6_rcv(struct sk_buff *skb)
+{
+	struct xfrm6_tunnel *handler;
+
+	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+		goto drop;
+
+	for_each_tunnel_rcu(tunnelmpls6_handlers, handler)
+		if (!handler->handler(skb))
+			return 0;
+
+	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
+
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+static int tunnel6_rcv(struct sk_buff *skb)
+{
+	struct xfrm6_tunnel *handler;
+
+	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+		goto drop;
+
+	for_each_tunnel_rcu(tunnel6_handlers, handler)
+		if (!handler->handler(skb))
+			return 0;
+
+	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
+
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
+static int tunnel6_rcv_cb(struct sk_buff *skb, u8 proto, int err)
+{
+	struct xfrm6_tunnel __rcu *head;
+	struct xfrm6_tunnel *handler;
+	int ret;
+
+	head = (proto == IPPROTO_IPV6) ? tunnel6_handlers : tunnel46_handlers;
+
+	for_each_tunnel_rcu(head, handler) {
+		if (handler->cb_handler) {
+			ret = handler->cb_handler(skb, err);
+			if (ret <= 0)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static const struct xfrm_input_afinfo tunnel6_input_afinfo = {
+	.family		=	AF_INET6,
+	.is_ipip	=	true,
+	.callback	=	tunnel6_rcv_cb,
+};
+#endif
+
+static int tunnel46_rcv(struct sk_buff *skb)
+{
+	struct xfrm6_tunnel *handler;
+
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		goto drop;
+
+	for_each_tunnel_rcu(tunnel46_handlers, handler)
+		if (!handler->handler(skb))
+			return 0;
+
+	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
+
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+static int tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+			u8 type, u8 code, int offset, __be32 info)
+{
+	struct xfrm6_tunnel *handler;
+
+	for_each_tunnel_rcu(tunnel6_handlers, handler)
+		if (!handler->err_handler(skb, opt, type, code, offset, info))
+			return 0;
+
+	return -ENOENT;
+}
+
+static int tunnel46_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+			 u8 type, u8 code, int offset, __be32 info)
+{
+	struct xfrm6_tunnel *handler;
+
+	for_each_tunnel_rcu(tunnel46_handlers, handler)
+		if (!handler->err_handler(skb, opt, type, code, offset, info))
+			return 0;
+
+	return -ENOENT;
+}
+
+static int tunnelmpls6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+			   u8 type, u8 code, int offset, __be32 info)
+{
+	struct xfrm6_tunnel *handler;
+
+	for_each_tunnel_rcu(tunnelmpls6_handlers, handler)
+		if (!handler->err_handler(skb, opt, type, code, offset, info))
+			return 0;
+
+	return -ENOENT;
+}
+
+static const struct inet6_protocol tunnel6_protocol = {
+	.handler	= tunnel6_rcv,
+	.err_handler	= tunnel6_err,
+	.flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
+};
+
+static const struct inet6_protocol tunnel46_protocol = {
+	.handler	= tunnel46_rcv,
+	.err_handler	= tunnel46_err,
+	.flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
+};
+
+static const struct inet6_protocol tunnelmpls6_protocol = {
+	.handler	= tunnelmpls6_rcv,
+	.err_handler	= tunnelmpls6_err,
+	.flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
+};
+
+static int __init tunnel6_init(void)
+{
+	if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) {
+		pr_err("%s: can't add protocol\n", __func__);
+		return -EAGAIN;
+	}
+	if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) {
+		pr_err("%s: can't add protocol\n", __func__);
+		inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
+		return -EAGAIN;
+	}
+	if (xfrm6_tunnel_mpls_supported() &&
+	    inet6_add_protocol(&tunnelmpls6_protocol, IPPROTO_MPLS)) {
+		pr_err("%s: can't add protocol\n", __func__);
+		inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
+		inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP);
+		return -EAGAIN;
+	}
+#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
+	if (xfrm_input_register_afinfo(&tunnel6_input_afinfo)) {
+		pr_err("%s: can't add input afinfo\n", __func__);
+		inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
+		inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP);
+		if (xfrm6_tunnel_mpls_supported())
+			inet6_del_protocol(&tunnelmpls6_protocol, IPPROTO_MPLS);
+		return -EAGAIN;
+	}
+#endif
+	return 0;
+}
+
+static void __exit tunnel6_fini(void)
+{
+#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
+	if (xfrm_input_unregister_afinfo(&tunnel6_input_afinfo))
+		pr_err("%s: can't remove input afinfo\n", __func__);
+#endif
+	if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP))
+		pr_err("%s: can't remove protocol\n", __func__);
+	if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6))
+		pr_err("%s: can't remove protocol\n", __func__);
+	if (xfrm6_tunnel_mpls_supported() &&
+	    inet6_del_protocol(&tunnelmpls6_protocol, IPPROTO_MPLS))
+		pr_err("%s: can't remove protocol\n", __func__);
+}
+
+module_init(tunnel6_init);
+module_exit(tunnel6_fini);
+MODULE_LICENSE("GPL");