1 files changed, 93 insertions, 14 deletions

diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index 6434bd5ce08..433672d07d0 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -17,6 +17,7 @@
 #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,
@@ -27,6 +28,47 @@ int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
 
 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;
@@ -36,9 +78,15 @@ static int xfrm6_tunnel_check_size(struct sk_buff *skb)
 	if (mtu < IPV6_MIN_MTU)
 		mtu = IPV6_MIN_MTU;
 
-	if (!skb->local_df && skb->len > mtu) {
+	if (!skb->ignore_df && skb->len > mtu) {
 		skb->dev = dst->dev;
-		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+
+		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;
 	}
 
@@ -66,30 +114,61 @@ int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
 	if (err)
 		return err;
 
-	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
-#ifdef CONFIG_NETFILTER
-	IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
-#endif
-
-	skb->protocol = htons(ETH_P_IPV6);
-	skb->local_df = 1;
+	skb->ignore_df = 1;
 
 	return x->outer_mode->output2(x, skb);
 }
 EXPORT_SYMBOL(xfrm6_prepare_output);
 
-static int xfrm6_output_finish(struct sk_buff *skb)
+int xfrm6_output_finish(struct sk_buff *skb)
 {
+	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
+	skb->protocol = htons(ETH_P_IPV6);
+
 #ifdef CONFIG_NETFILTER
 	IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
 #endif
 
-	skb->protocol = htons(ETH_P_IPV6);
 	return xfrm_output(skb);
 }
 
-int xfrm6_output(struct sk_buff *skb)
+static int __xfrm6_output(struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct xfrm_state *x = dst->xfrm;
+	int mtu;
+
+#ifdef CONFIG_NETFILTER
+	if (!x) {
+		IP6CB(skb)->flags |= IP6SKB_REROUTED;
+		return dst_output(skb);
+	}
+#endif
+
+	if (skb->protocol == htons(ETH_P_IPV6))
+		mtu = ip6_skb_dst_mtu(skb);
+	else
+		mtu = dst_mtu(skb_dst(skb));
+
+	if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
+		xfrm6_local_rxpmtu(skb, mtu);
+		return -EMSGSIZE;
+	} else if (!skb->ignore_df && skb->len > mtu && skb->sk) {
+		xfrm_local_error(skb, mtu);
+		return -EMSGSIZE;
+	}
+
+	if (x->props.mode == XFRM_MODE_TUNNEL &&
+	    ((skb->len > mtu && !skb_is_gso(skb)) ||
+		dst_allfrag(skb_dst(skb)))) {
+			return ip6_fragment(skb, x->outer_mode->afinfo->output_finish);
+	}
+	return x->outer_mode->afinfo->output_finish(skb);
+}
+
+int xfrm6_output(struct sock *sk, struct sk_buff *skb)
 {
-	return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL,
-		       skb_dst(skb)->dev, xfrm6_output_finish);
+	return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb,
+			    NULL, skb_dst(skb)->dev, __xfrm6_output,
+			    !(IP6CB(skb)->flags & IP6SKB_REROUTED));
 }