net: introduce skb_transport_header_was_set()

We have skb_mac_header_was_set() helper to tell if mac_header
was set on a skb. We would like the same for transport_header.

__netif_receive_skb() doesn't reset the transport header if already
set by GRO layer.

Note that network stacks usually reset the transport header anyway,
after pulling the network header, so this change only allows
a followup patch to have more precise qdisc pkt_len computation
for GSO packets at ingress side.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 320e976d5ab8..8b2256e880e0 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1492,6 +1492,11 @@ static inline void skb_set_inner_network_header(struct sk_buff *skb,
         skb->inner_network_header += offset;
 }
 
+static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
+{
+        return skb->transport_header != ~0U;
+}
+
 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
 {
         return skb->head + skb->transport_header;
@@ -1580,6 +1585,11 @@ static inline void skb_set_inner_network_header(struct sk_buff *skb,
         skb->inner_network_header = skb->data + offset;
 }
 
+static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
+{
+        return skb->transport_header != NULL;
+}
+
 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
 {
         return skb->transport_header;