5 files changed, 15 insertions, 9 deletions

diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 60925fe..4e8e3b0 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -125,6 +125,7 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
 {
 	int ah_hlen;
 	int ihl;
+	int nexthdr;
 	int err = -EINVAL;
 	struct iphdr *iph;
 	struct ip_auth_hdr *ah;
@@ -136,6 +137,7 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
 
 	ah = (struct ip_auth_hdr *)skb->data;
 	ahp = x->data;
+	nexthdr = ah->nexthdr;
 	ah_hlen = (ah->hdrlen + 2) << 2;
 
 	if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
@@ -182,13 +184,12 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
 			goto out;
 		}
 	}
-	((struct iphdr*)work_buf)->protocol = ah->nexthdr;
 	skb->network_header += ah_hlen;
 	memcpy(skb_network_header(skb), work_buf, ihl);
 	skb->transport_header = skb->network_header;
 	__skb_pull(skb, ah_hlen + ihl);
 
-	return 0;
+	return nexthdr;
 
 out:
 	return err;
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 8377bed..6b1a31a74 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -257,12 +257,11 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
 			skb->ip_summed = CHECKSUM_UNNECESSARY;
 	}
 
-	iph->protocol = nexthdr[1];
 	pskb_trim(skb, skb->len - alen - padlen - 2);
 	__skb_pull(skb, sizeof(*esph) + esp->conf.ivlen);
 	skb_set_transport_header(skb, -ihl);
 
-	return 0;
+	return nexthdr[1];
 
 out:
 	return -EINVAL;
diff --git a/net/ipv4/ipcomp.c b/net/ipv4/ipcomp.c
index 32b02de..0bfeb02 100644
--- a/net/ipv4/ipcomp.c
+++ b/net/ipv4/ipcomp.c
@@ -75,7 +75,6 @@ out:
 static int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
 {
 	int err = -ENOMEM;
-	struct iphdr *iph;
 	struct ip_comp_hdr *ipch;
 
 	if (skb_linearize_cow(skb))
@@ -84,12 +83,14 @@ static int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
 	skb->ip_summed = CHECKSUM_NONE;
 
 	/* Remove ipcomp header and decompress original payload */
-	iph = ip_hdr(skb);
 	ipch = (void *)skb->data;
-	iph->protocol = ipch->nexthdr;
 	skb->transport_header = skb->network_header + sizeof(*ipch);
 	__skb_pull(skb, sizeof(*ipch));
 	err = ipcomp_decompress(x, skb);
+	if (err)
+		goto out;
+
+	err = ipch->nexthdr;
 
 out:
 	return err;
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
index 2fa1082..e9bbfde 100644
--- a/net/ipv4/xfrm4_input.c
+++ b/net/ipv4/xfrm4_input.c
@@ -54,12 +54,14 @@ static int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
 	int xfrm_nr = 0;
 	int decaps = 0;
 	int err = xfrm4_parse_spi(skb, ip_hdr(skb)->protocol, &spi, &seq);
+	unsigned int nhoff = offsetof(struct iphdr, protocol);
 
 	if (err != 0)
 		goto drop;
 
 	do {
 		const struct iphdr *iph = ip_hdr(skb);
+		int nexthdr;
 
 		if (xfrm_nr == XFRM_MAX_DEPTH)
 			goto drop;
@@ -82,9 +84,12 @@ static int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
 		if (xfrm_state_check_expire(x))
 			goto drop_unlock;
 
-		if (x->type->input(x, skb))
+		nexthdr = x->type->input(x, skb);
+		if (nexthdr <= 0)
 			goto drop_unlock;
 
+		skb_network_header(skb)[nhoff] = nexthdr;
+
 		/* only the first xfrm gets the encap type */
 		encap_type = 0;
 
diff --git a/net/ipv4/xfrm4_tunnel.c b/net/ipv4/xfrm4_tunnel.c
index e1fafc1..1312417 100644
--- a/net/ipv4/xfrm4_tunnel.c
+++ b/net/ipv4/xfrm4_tunnel.c
@@ -18,7 +18,7 @@ static int ipip_output(struct xfrm_state *x, struct sk_buff *skb)
 
 static int ipip_xfrm_rcv(struct xfrm_state *x, struct sk_buff *skb)
 {
-	return 0;
+	return IPPROTO_IP;
 }
 
 static int ipip_init_state(struct xfrm_state *x)