[PATCH net-next 2/6] net: igb: use skb_csum_is_sctp instead of protocol check

[Xin Long]

Using skb_csum_is_sctp is a easier way to validate it's a SCTP
CRC checksum offload packet, and there is no need to parse the
packet to check its proto field, especially when it's a UDP or
GRE encapped packet.

So this patch also makes igb support SCTP CRC checksum offload
for UDP and GRE encapped packets.

Signed-off-by: Xin Long <lucien....@gmail.com>
---
 drivers/net/ethernet/intel/igb/igb_main.c | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c 
b/drivers/net/ethernet/intel/igb/igb_main.c
index 03f78fd..8757ad0 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -5959,15 +5959,6 @@ static int igb_tso(struct igb_ring *tx_ring,
        return 1;
 }
 
-static inline bool igb_ipv6_csum_is_sctp(struct sk_buff *skb)
-{
-       unsigned int offset = 0;
-
-       ipv6_find_hdr(skb, &offset, IPPROTO_SCTP, NULL, NULL);
-
-       return offset == skb_checksum_start_offset(skb);
-}
-
 static void igb_tx_csum(struct igb_ring *tx_ring, struct igb_tx_buffer *first)
 {
        struct sk_buff *skb = first->skb;
@@ -5990,10 +5981,7 @@ static void igb_tx_csum(struct igb_ring *tx_ring, struct 
igb_tx_buffer *first)
                break;
        case offsetof(struct sctphdr, checksum):
                /* validate that this is actually an SCTP request */
-               if (((first->protocol == htons(ETH_P_IP)) &&
-                    (ip_hdr(skb)->protocol == IPPROTO_SCTP)) ||
-                   ((first->protocol == htons(ETH_P_IPV6)) &&
-                    igb_ipv6_csum_is_sctp(skb))) {
+               if (skb_csum_is_sctp(skb)) {
                        type_tucmd = E1000_ADVTXD_TUCMD_L4T_SCTP;
                        break;
                }
-- 
2.1.0