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_output.c b/net/ipv6/xfrm6_output.c
new file mode 100644
index 0000000..4d09ce6
--- /dev/null
+++ b/net/ipv6/xfrm6_output.c
@@ -0,0 +1,188 @@
+/*
+ * xfrm6_output.c - Common IPsec encapsulation code for IPv6.
+ * Copyright (C) 2002 USAGI/WIDE Project
+ * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/if_ether.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/icmpv6.h>
+#include <linux/netfilter_ipv6.h>
+#include <net/dst.h>
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+#include <net/xfrm.h>
+
+int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
+ u8 **prevhdr)
+{
+ return ip6_find_1stfragopt(skb, prevhdr);
+}
+EXPORT_SYMBOL(xfrm6_find_1stfragopt);
+
+static int xfrm6_local_dontfrag(struct sk_buff *skb)
+{
+ int proto;
+ struct sock *sk = skb->sk;
+
+ if (sk) {
+ if (sk->sk_family != AF_INET6)
+ return 0;
+
+ proto = sk->sk_protocol;
+ if (proto == IPPROTO_UDP || proto == IPPROTO_RAW)
+ return inet6_sk(sk)->dontfrag;
+ }
+
+ return 0;
+}
+
+static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
+{
+ struct flowi6 fl6;
+ struct sock *sk = skb->sk;
+
+ fl6.flowi6_oif = sk->sk_bound_dev_if;
+ fl6.daddr = ipv6_hdr(skb)->daddr;
+
+ ipv6_local_rxpmtu(sk, &fl6, mtu);
+}
+
+void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
+{
+ struct flowi6 fl6;
+ const struct ipv6hdr *hdr;
+ struct sock *sk = skb->sk;
+
+ hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
+ fl6.fl6_dport = inet_sk(sk)->inet_dport;
+ fl6.daddr = hdr->daddr;
+
+ ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
+}
+
+static int xfrm6_tunnel_check_size(struct sk_buff *skb)
+{
+ int mtu, ret = 0;
+ struct dst_entry *dst = skb_dst(skb);
+
+ mtu = dst_mtu(dst);
+ if (mtu < IPV6_MIN_MTU)
+ mtu = IPV6_MIN_MTU;
+
+ if (!skb->ignore_df && skb->len > mtu) {
+ skb->dev = dst->dev;
+ skb->protocol = htons(ETH_P_IPV6);
+
+ if (xfrm6_local_dontfrag(skb))
+ xfrm6_local_rxpmtu(skb, mtu);
+ else if (skb->sk)
+ xfrm_local_error(skb, mtu);
+ else
+ icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+ ret = -EMSGSIZE;
+ }
+
+ return ret;
+}
+
+int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err;
+
+ err = xfrm6_tunnel_check_size(skb);
+ if (err)
+ return err;
+
+ XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
+
+ return xfrm6_extract_header(skb);
+}
+
+int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err;
+
+ err = xfrm_inner_extract_output(x, skb);
+ if (err)
+ return err;
+
+ skb->ignore_df = 1;
+ skb->protocol = htons(ETH_P_IPV6);
+
+ return x->outer_mode->output2(x, skb);
+}
+EXPORT_SYMBOL(xfrm6_prepare_output);
+
+int xfrm6_output_finish(struct sock *sk, struct sk_buff *skb)
+{
+ memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
+
+#ifdef CONFIG_NETFILTER
+ IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
+#endif
+
+ return xfrm_output(sk, skb);
+}
+
+static int __xfrm6_output_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ struct xfrm_state *x = skb_dst(skb)->xfrm;
+
+ return x->outer_mode->afinfo->output_finish(sk, skb);
+}
+
+static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ struct xfrm_state *x = dst->xfrm;
+ int mtu;
+ bool toobig;
+
+#ifdef CONFIG_NETFILTER
+ if (!x) {
+ IP6CB(skb)->flags |= IP6SKB_REROUTED;
+ return dst_output(net, sk, skb);
+ }
+#endif
+
+ if (x->props.mode != XFRM_MODE_TUNNEL)
+ goto skip_frag;
+
+ if (skb->protocol == htons(ETH_P_IPV6))
+ mtu = ip6_skb_dst_mtu(skb);
+ else
+ mtu = dst_mtu(skb_dst(skb));
+
+ toobig = skb->len > mtu && !skb_is_gso(skb);
+
+ if (toobig && xfrm6_local_dontfrag(skb)) {
+ xfrm6_local_rxpmtu(skb, mtu);
+ return -EMSGSIZE;
+ } else if (!skb->ignore_df && toobig && skb->sk) {
+ xfrm_local_error(skb, mtu);
+ return -EMSGSIZE;
+ }
+
+ if (toobig || dst_allfrag(skb_dst(skb)))
+ return ip6_fragment(net, sk, skb,
+ __xfrm6_output_finish);
+
+skip_frag:
+ return x->outer_mode->afinfo->output_finish(sk, skb);
+}
+
+int xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
+ net, sk, skb, NULL, skb_dst(skb)->dev,
+ __xfrm6_output,
+ !(IP6CB(skb)->flags & IP6SKB_REROUTED));
+}