tg3: fix ipv6 header length computation

tg3_start_xmit() makes the wrong assumption for TSOV6 that skb->head
doesnt include any payload data.

if (skb_is_gso_v6(skb))
	hdr_len = skb_headlen(skb) - ETH_HLEN;

This is not true anymore after commit f07d960df3 (tcp: avoid frag
allocation for small frames)

We should instead use : skb_transport_offset(skb) + tcp_hdrlen(skb)

Its also true for IPv4

(cherry picked from commit a5a1195559f2e20bd975f58e50f53ebe84d5cca6)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Matt Carlson <mcarlson@broadcom.com>
CC: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Joe Jin <joe.jin@oracle.com>

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 268b4916a1cd8bc4d65a90bb94fd92b65758b609..3b8368bbeb17f5c74a2903b3af23601ded504954 100644 (file)
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -6699,14 +6699,9 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
                iph = ip_hdr(skb);
                tcp_opt_len = tcp_optlen(skb);
 
-               if (skb_is_gso_v6(skb)) {
-                       hdr_len = skb_headlen(skb) - ETH_HLEN;
-               } else {
-                       u32 ip_tcp_len;
-
-                       ip_tcp_len = ip_hdrlen(skb) + sizeof(struct tcphdr);
-                       hdr_len = ip_tcp_len + tcp_opt_len;
+               hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb) - ETH_HLEN;
 
+               if (!skb_is_gso_v6(skb)) {
                        iph->check = 0;
                        iph->tot_len = htons(mss + hdr_len);
                }