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-rw-r--r--net/ipv6/tunnel6.c305
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");