net: core: handle encapsulation offloads when computing segment lengths

if ->encapsulation is set we have to use inner_tcp_hdrlen and add the
size of the inner network headers too.

This is 'mostly harmless'; tbf might send skb that is slightly over
quota or drop skb even if it would have fit.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 3 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 61059a05ec95..c16615bfb61e 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4070,15 +4070,22 @@ EXPORT_SYMBOL_GPL(skb_scrub_packet);
 unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
 {
         const struct skb_shared_info *shinfo = skb_shinfo(skb);
+        unsigned int thlen = 0;
 
-        if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
-                return tcp_hdrlen(skb) + shinfo->gso_size;
+        if (skb->encapsulation) {
+                thlen = skb_inner_transport_header(skb) -
+                        skb_transport_header(skb);
 
+                if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
+                        thlen += inner_tcp_hdrlen(skb);
+        } else if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
+                thlen = tcp_hdrlen(skb);
+        }
         /* UFO sets gso_size to the size of the fragmentation
          * payload, i.e. the size of the L4 (UDP) header is already
          * accounted for.
          */
-        return shinfo->gso_size;
+        return thlen + shinfo->gso_size;
 }
 EXPORT_SYMBOL_GPL(skb_gso_transport_seglen);