Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 209 insertions, 0 deletions

diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
new file mode 100644
index 000000000..fbcec4827
--- /dev/null
+++ b/net/ipv6/xfrm6_output.c
@@ -0,0 +1,209 @@
+/*
+ * 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);
+
+	if (skb->ignore_df)
+		goto out;
+
+	mtu = dst_mtu(dst);
+	if (mtu < IPV6_MIN_MTU)
+		mtu = IPV6_MIN_MTU;
+
+	if ((!skb_is_gso(skb) && skb->len > mtu) ||
+	    (skb_is_gso(skb) &&
+	     !skb_gso_validate_network_len(skb, ip6_skb_dst_mtu(skb)))) {
+		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;
+	}
+out:
+	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)));
+
+	IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
+
+	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_noneed_fragment(struct sk_buff *skb)
+{
+	struct frag_hdr *fh;
+	u8 prevhdr = ipv6_hdr(skb)->nexthdr;
+
+	if (prevhdr != NEXTHDR_FRAGMENT)
+		return 0;
+	fh = (struct frag_hdr *)(skb->data + sizeof(struct ipv6hdr));
+	if (fh->nexthdr == NEXTHDR_ESP || fh->nexthdr == NEXTHDR_AUTH)
+		return 1;
+	return 0;
+}
+
+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;
+	unsigned 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);
+		kfree_skb(skb);
+		return -EMSGSIZE;
+	} else if (toobig && xfrm6_noneed_fragment(skb)) {
+		skb->ignore_df = 1;
+		goto skip_frag;
+	} else if (!skb->ignore_df && toobig && skb->sk) {
+		xfrm_local_error(skb, mtu);
+		kfree_skb(skb);
+		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));
+}