From fab2bdc84727620e644e637bed88c512b9c05266 Mon Sep 17 00:00:00 2001

From: Slawomir Laba <slawomirx.laba@intel.com>

Date: Thu, 10 Sep 2020 07:57:04 +0000

Subject: [PATCH 06/19] i40e: Fix flow for IPv6 next header (extension header)

Git-commit: 92c6058024e87087cf1b99b0389d67c0a886360e

Patch-mainline: v5.12-rc1

References: git-fixes

When a packet contains an IPv6 header with next header which is

an extension header and not a protocol one, the kernel function

skb_transport_header called with such sk_buff will return a

pointer to the extension header and not to the TCP one.

The above explained call caused a problem with packet processing

for skb with encapsulation for tunnel with I40E_TX_CTX_EXT_IP_IPV6.

The extension header was not skipped at all.

The ipv6_skip_exthdr function does check if next header of the IPV6

header is an extension header and doesn't modify the l4_proto pointer

if it points to a protocol header value so its safe to omit the

comparison of exthdr and l4.hdr pointers. The ipv6_skip_exthdr can

return value -1. This means that the skipping process failed

and there is something wrong with the packet so it will be dropped.

Fixes: a3fd9d8876a5 ("i40e/i40evf: Handle IPv6 extension headers in checksum offload")

Signed-off-by: Slawomir Laba <slawomirx.laba@intel.com>

Signed-off-by: Przemyslaw Patynowski <przemyslawx.patynowski@intel.com>

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>

Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>

---

 drivers/net/ethernet/intel/i40e/i40e_txrx.c | 9 ++++++---

 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c

index 734d95943967..4cb16178adb9 100644

--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c

+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c

@@ -3109,13 +3109,16 @@ static int i40e_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags,

 			l4_proto = ip.v4->protocol;

 		} else if (*tx_flags & I40E_TX_FLAGS_IPV6) {

+			int ret;

+

 			tunnel |= I40E_TX_CTX_EXT_IP_IPV6;

 			exthdr = ip.hdr + sizeof(*ip.v6);

 			l4_proto = ip.v6->nexthdr;

-			if (l4.hdr != exthdr)

-				ipv6_skip_exthdr(skb, exthdr - skb->data,

-						 &l4_proto, &frag_off);

+			ret = ipv6_skip_exthdr(skb, exthdr - skb->data,

+					       &l4_proto, &frag_off);

+			if (ret < 0)

+				return -1;

 		}

 		/* define outer transport */

-- 

2.16.4