From: Jesse Brandeburg <jesse.brandeburg@intel.com>
Date: Tue, 20 Jun 2017 15:16:58 -0700
Subject: i40e/i40evf: make IPv6 ATR code clearer
Patch-mainline: v4.14-rc1
Git-commit: 601a2e7ac5acd4a1681ba7ca6cefe5f9897a3c28
References: bsc#1056658 FATE#322188 bsc#1056662 FATE#322186

This just reorders some local vars and makes the code flow
clearer.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Benjamin Poirier <bpoirier@suse.com>
---
 drivers/net/ethernet/intel/i40e/i40e_txrx.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2453,9 +2453,15 @@ static void i40e_atr(struct i40e_ring *t
 		hlen = (hdr.network[0] & 0x0F) << 2;
 		l4_proto = hdr.ipv4->protocol;
 	} else {
-		hlen = hdr.network - skb->data;
-		l4_proto = ipv6_find_hdr(skb, &hlen, IPPROTO_TCP, NULL, NULL);
-		hlen -= hdr.network - skb->data;
+		/* find the start of the innermost ipv6 header */
+		unsigned int inner_hlen = hdr.network - skb->data;
+		unsigned int h_offset = inner_hlen;
+
+		/* this function updates h_offset to the end of the header */
+		l4_proto =
+		  ipv6_find_hdr(skb, &h_offset, IPPROTO_TCP, NULL, NULL);
+		/* hlen will contain our best estimate of the tcp header */
+		hlen = h_offset - inner_hlen;
 	}
 
 	if (l4_proto != IPPROTO_TCP)