[PATCH net-next v2 3/4] net: gro: set inner_network_header in receive phase

[Richard Gobert <richardbgobert@gmail.com>]

This patch sets network_header and inner_network_header to their respective
values during the receive phase of GRO. This allows us to use
inner_network_header later on in GRO. network_header is already set in
dev_gro_receive and under encapsulation inner_network_header is set.

Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
---
 include/net/gro.h      | 13 +++++++++++--
 net/8021q/vlan_core.c  |  5 +++++
 net/ethernet/eth.c     |  1 +
 net/ipv4/af_inet.c     |  9 ++-------
 net/ipv4/gre_offload.c |  1 +
 net/ipv6/ip6_offload.c | 12 +++++-------
 6 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 7515e6bcbb7d..db27b6851360 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -441,6 +441,7 @@ struct sk_buff *eth_gro_receive(struct list_head *head, struct sk_buff *skb)
 
 	skb_gro_pull(skb, sizeof(*eh));
 	skb_gro_postpull_rcsum(skb, eh, sizeof(*eh));
+	skb_set_inner_network_header(skb, skb_gro_offset(skb));
 
 	pp = indirect_call_gro_receive_inet(ptype->callbacks.gro_receive,
 					    ipv6_gro_receive, inet_gro_receive,
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 9334b563a88b..09ab9ac4420b 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1567,10 +1567,6 @@ struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
 
 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
 	NAPI_GRO_CB(skb)->flush |= flush;
-	skb_set_network_header(skb, off);
-	/* The above will be needed by the transport layer if there is one
-	 * immediately following this IP hdr.
-	 */
 
 	/* Note : No need to call skb_gro_postpull_rcsum() here,
 	 * as we already checked checksum over ipv4 header was 0
@@ -1596,6 +1592,7 @@ static struct sk_buff *ipip_gro_receive(struct list_head *head,
 	}
 
 	NAPI_GRO_CB(skb)->encap_mark = 1;
+	skb_set_inner_network_header(skb, skb_gro_offset(skb));
 
 	return inet_gro_receive(head, skb);
 }
@@ -1648,10 +1645,8 @@ int inet_gro_complete(struct sk_buff *skb, int prior_off, int nhoff)
 	int proto = iph->protocol;
 	int err = -ENOSYS;
 
-	if (skb->encapsulation) {
+	if (skb->encapsulation)
 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
-		skb_set_inner_network_header(skb, nhoff);
-	}
 
 	iph_set_totlen(iph, skb->len - nhoff);
 	csum_replace2(&iph->check, totlen, iph->tot_len);
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index d4520c3f7c09..bfc3a0cbb3a3 100644
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -224,6 +224,7 @@ static struct sk_buff *gre_gro_receive(struct list_head *head,
 	/* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
 	skb_gro_postpull_rcsum(skb, greh, grehlen);
 
+	skb_set_inner_network_header(skb, skb_gro_offset(skb));
 	pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb);
 	flush = 0;
 
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index e3a05b84c76a..29601be9fa90 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -67,7 +67,7 @@ static int ipv6_gro_pull_exthdrs(struct sk_buff *skb, int off, int proto)
 		off += len;
 	}
 
-	skb_gro_pull(skb, off - skb_network_offset(skb));
+	skb_gro_pull(skb, off - skb_gro_network_offset(skb));
 	return proto;
 }
 
@@ -236,8 +236,6 @@ INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
 	if (unlikely(!iph))
 		goto out;
 
-	skb_set_network_header(skb, off);
-
 	flush += ntohs(iph->payload_len) != skb->len - hlen;
 
 	proto = iph->nexthdr;
@@ -259,7 +257,7 @@ INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
 	NAPI_GRO_CB(skb)->proto = proto;
 
 	flush--;
-	nlen = skb_network_header_len(skb);
+	nlen = skb_gro_offset(skb) - off;
 
 	list_for_each_entry(p, head, list) {
 		const struct ipv6hdr *iph2;
@@ -327,6 +325,7 @@ static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
 	}
 
 	NAPI_GRO_CB(skb)->encap_mark = 1;
+	skb_set_inner_network_header(skb, skb_gro_offset(skb));
 
 	return ipv6_gro_receive(head, skb);
 }
@@ -342,6 +341,7 @@ static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
 	}
 
 	NAPI_GRO_CB(skb)->encap_mark = 1;
+	skb_set_inner_network_header(skb, skb_gro_offset(skb));
 
 	return inet_gro_receive(head, skb);
 }
@@ -355,10 +355,8 @@ INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb,
 	u32 payload_len;
 	int nhlen;
 
-	if (skb->encapsulation) {
+	if (skb->encapsulation)
 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
-		skb_set_inner_network_header(skb, nhoff);
-	}
 
 	payload_len = skb->len - nhoff - sizeof(*iph);
 	if (unlikely(payload_len > IPV6_MAXPLEN)) {
diff --git a/include/net/gro.h b/include/net/gro.h
index cb7282bf3d63..923cbcc4c2fa 100644
--- a/include/net/gro.h
+++ b/include/net/gro.h
@@ -171,12 +171,21 @@ static inline void *skb_gro_header(struct sk_buff *skb, unsigned int hlen,
 	return ptr;
 }
 
+static inline int skb_gro_network_offset(const struct sk_buff *skb)
+{
+	const u32 mask = NAPI_GRO_CB(skb)->encap_mark - 1;
+
+	return (skb_network_offset(skb) & mask) | (skb_inner_network_offset(skb) & ~mask);
+}
+
 static inline void *skb_gro_network_header(const struct sk_buff *skb)
 {
+	const int offset = skb_gro_network_offset(skb);
+
 	if (skb_gro_may_pull(skb, skb_gro_offset(skb)))
-		return skb_gro_header_fast(skb, skb_network_offset(skb));
+		return skb_gro_header_fast(skb, offset);
 
-	return skb_network_header(skb);
+	return skb->data + offset;
 }
 
 static inline __wsum inet_gro_compute_pseudo(const struct sk_buff *skb,
diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c
index 247704cf70af..a61bfcff6250 100644
--- a/net/8021q/vlan_core.c
+++ b/net/8021q/vlan_core.c
@@ -478,6 +478,11 @@ static struct sk_buff *vlan_gro_receive(struct list_head *head,
 	if (unlikely(!vhdr))
 		goto out;
 
+	if (NAPI_GRO_CB(skb)->encap_mark)
+		skb_set_inner_network_header(skb, hlen);
+	else
+		skb_set_network_header(skb, hlen);
+
 	type = vhdr->h_vlan_encapsulated_proto;
 
 	ptype = gro_find_receive_by_type(type);
-- 
2.36.1