[PATCH net-next 0/2] ipv6: IPsec pmtu/fragmentation fixes

@@ -1193,6 +1193,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 	struct sk_buff *skb;
 	unsigned int maxfraglen, fragheaderlen;
 	int exthdrlen;
+	int dst_exthdrlen;
 	int hh_len;
 	int mtu;
 	int copy;

@@ -1248,7 +1249,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 		np->cork.hop_limit = hlimit;
 		np->cork.tclass = tclass;
 		mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
-		      rt->dst.dev->mtu : dst_mtu(rt->dst.path);
+		      rt->dst.dev->mtu : dst_mtu(&rt->dst);
 		if (np->frag_size < mtu) {
 			if (np->frag_size)
 				mtu = np->frag_size;

@@ -1259,16 +1260,17 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 		cork->length = 0;
 		sk->sk_sndmsg_page = NULL;
 		sk->sk_sndmsg_off = 0;
-		exthdrlen = rt->dst.header_len + (opt ? opt->opt_flen : 0) -
-			    rt->rt6i_nfheader_len;
+		exthdrlen = (opt ? opt->opt_flen : 0) - rt->rt6i_nfheader_len;
 		length += exthdrlen;
 		transhdrlen += exthdrlen;
+		dst_exthdrlen = rt->dst.header_len;
 	} else {
 		rt = (struct rt6_info *)cork->dst;
 		fl6 = &inet->cork.fl.u.ip6;
 		opt = np->cork.opt;
 		transhdrlen = 0;
 		exthdrlen = 0;
+		dst_exthdrlen = 0;
 		mtu = cork->fragsize;
 	}
 

@@ -1368,6 +1370,8 @@ alloc_new_skb:
 			else
 				alloclen = datalen + fragheaderlen;
 
+			alloclen += dst_exthdrlen;
+
 			/*
 			 * The last fragment gets additional space at tail.
 			 * Note: we overallocate on fragments with MSG_MODE

@@ -1419,9 +1423,9 @@ alloc_new_skb:
 			/*
 			 *	Find where to start putting bytes
 			 */
-			data = skb_put(skb, fraglen);
-			skb_set_network_header(skb, exthdrlen);
-			data += fragheaderlen;
+			data = skb_put(skb, fraglen + dst_exthdrlen);
+			skb_set_network_header(skb, exthdrlen + dst_exthdrlen);
+			data += fragheaderlen + dst_exthdrlen;
 			skb->transport_header = (skb->network_header +
 						 fragheaderlen);
 			if (fraggap) {

@@ -1434,6 +1438,7 @@ alloc_new_skb:
 				pskb_trim_unique(skb_prev, maxfraglen);
 			}
 			copy = datalen - transhdrlen - fraggap;
+
 			if (copy < 0) {
 				err = -EINVAL;
 				kfree_skb(skb);

@@ -1448,6 +1453,7 @@ alloc_new_skb:
 			length -= datalen - fraggap;
 			transhdrlen = 0;
 			exthdrlen = 0;
+			dst_exthdrlen = 0;
 			csummode = CHECKSUM_NONE;
 
 			/*

@@ -542,8 +542,7 @@ static int rawv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 		goto out;
 
 	offset = rp->offset;
-	total_len = inet_sk(sk)->cork.base.length - (skb_network_header(skb) -
-						     skb->data);
+	total_len = inet_sk(sk)->cork.base.length;
 	if (offset >= total_len - 1) {
 		err = -EINVAL;
 		ip6_flush_pending_frames(sk);

@@ -28,6 +28,43 @@ 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) {
+		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;
+	ipv6_addr_copy(&fl6.daddr, &ipv6_hdr(skb)->daddr);
+
+	ipv6_local_rxpmtu(sk, &fl6, mtu);
+}
+
+static void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
+{
+	struct flowi6 fl6;
+	struct sock *sk = skb->sk;
+
+	fl6.fl6_dport = inet_sk(sk)->inet_dport;
+	ipv6_addr_copy(&fl6.daddr, &ipv6_hdr(skb)->daddr);
+
+	ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
+}
+
 static int xfrm6_tunnel_check_size(struct sk_buff *skb)
 {
 	int mtu, ret = 0;

@@ -39,7 +76,13 @@ static int xfrm6_tunnel_check_size(struct sk_buff *skb)
 
 	if (!skb->local_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)
+			xfrm6_local_error(skb, mtu);
+		else
+			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 		ret = -EMSGSIZE;
 	}
 

@@ -93,9 +136,18 @@ static int __xfrm6_output(struct sk_buff *skb)
 {
 	struct dst_entry *dst = skb_dst(skb);
 	struct xfrm_state *x = dst->xfrm;
+	int mtu = ip6_skb_dst_mtu(skb);
+
+	if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
+		xfrm6_local_rxpmtu(skb, mtu);
+		return -EMSGSIZE;
+	} else if (!skb->local_df && skb->len > mtu && skb->sk) {
+		xfrm6_local_error(skb, mtu);
+		return -EMSGSIZE;
+	}
 
 	if ((x && x->props.mode == XFRM_MODE_TUNNEL) &&
-	    ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
+	    ((skb->len > mtu && !skb_is_gso(skb)) ||
 		dst_allfrag(skb_dst(skb)))) {
 			return ip6_fragment(skb, x->outer_mode->afinfo->output_finish);
 	}