File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
new file mode 100644
index 0000000..372855e
--- /dev/null
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -0,0 +1,125 @@
+/*
+ * xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
+ *
+ * Copyright (C) 2002 USAGI/WIDE Project
+ * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <linux/gfp.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/stringify.h>
+#include <net/dsfield.h>
+#include <net/dst.h>
+#include <net/inet_ecn.h>
+#include <net/ip6_route.h>
+#include <net/ipv6.h>
+#include <net/xfrm.h>
+
+static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
+{
+ struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
+
+ if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
+ IP6_ECN_set_ce(skb, inner_iph);
+}
+
+/* Add encapsulation header.
+ *
+ * The top IP header will be constructed per RFC 2401.
+ */
+static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ struct ipv6hdr *top_iph;
+ int dsfield;
+
+ skb_set_network_header(skb, -x->props.header_len);
+ skb->mac_header = skb->network_header +
+ offsetof(struct ipv6hdr, nexthdr);
+ skb->transport_header = skb->network_header + sizeof(*top_iph);
+ top_iph = ipv6_hdr(skb);
+
+ top_iph->version = 6;
+
+ memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
+ sizeof(top_iph->flow_lbl));
+ top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
+
+ if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
+ dsfield = 0;
+ else
+ dsfield = XFRM_MODE_SKB_CB(skb)->tos;
+ dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos);
+ if (x->props.flags & XFRM_STATE_NOECN)
+ dsfield &= ~INET_ECN_MASK;
+ ipv6_change_dsfield(top_iph, 0, dsfield);
+ top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
+ top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
+ top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
+ return 0;
+}
+
+#define for_each_input_rcu(head, handler) \
+ for (handler = rcu_dereference(head); \
+ handler != NULL; \
+ handler = rcu_dereference(handler->next))
+
+
+static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err = -EINVAL;
+
+ if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
+ goto out;
+ if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+ goto out;
+
+ err = skb_unclone(skb, GFP_ATOMIC);
+ if (err)
+ goto out;
+
+ if (x->props.flags & XFRM_STATE_DECAP_DSCP)
+ ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
+ ipipv6_hdr(skb));
+ if (!(x->props.flags & XFRM_STATE_NOECN))
+ ipip6_ecn_decapsulate(skb);
+
+ skb_reset_network_header(skb);
+ skb_mac_header_rebuild(skb);
+
+ err = 0;
+
+out:
+ return err;
+}
+
+static struct xfrm_mode xfrm6_tunnel_mode = {
+ .input2 = xfrm6_mode_tunnel_input,
+ .input = xfrm_prepare_input,
+ .output2 = xfrm6_mode_tunnel_output,
+ .output = xfrm6_prepare_output,
+ .owner = THIS_MODULE,
+ .encap = XFRM_MODE_TUNNEL,
+ .flags = XFRM_MODE_FLAG_TUNNEL,
+};
+
+static int __init xfrm6_mode_tunnel_init(void)
+{
+ return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
+}
+
+static void __exit xfrm6_mode_tunnel_exit(void)
+{
+ int err;
+
+ err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
+ BUG_ON(err);
+}
+
+module_init(xfrm6_mode_tunnel_init);
+module_exit(xfrm6_mode_tunnel_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);