queue-4.4/net-mvpp2-extract-the-correct-ethtype-from-the-skb-for-tx-csum-offload.patch

   1 From foo@baz Tue Oct 16 16:15:55 CEST 2018
   2 From: Maxime Chevallier <maxime.chevallier@bootlin.com>
   3 Date: Fri, 5 Oct 2018 09:04:40 +0200
   4 Subject: net: mvpp2: Extract the correct ethtype from the skb for tx csum offload
   5
   6 From: Maxime Chevallier <maxime.chevallier@bootlin.com>
   7
   8 [ Upstream commit 35f3625c21852ad839f20c91c7d81c4c1101e207 ]
   9
  10 When offloading the L3 and L4 csum computation on TX, we need to extract
  11 the l3_proto from the ethtype, independently of the presence of a vlan
  12 tag.
  13
  14 The actual driver uses skb->protocol as-is, resulting in packets with
  15 the wrong L4 checksum being sent when there's a vlan tag in the packet
  16 header and checksum offloading is enabled.
  17
  18 This commit makes use of vlan_protocol_get() to get the correct ethtype
  19 regardless the presence of a vlan tag.
  20
  21 Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit")
  22 Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
  23 Signed-off-by: David S. Miller <davem@davemloft.net>
  24 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  25 ---
  26  drivers/net/ethernet/marvell/mvpp2.c |   10 ++++++----
  27  1 file changed, 6 insertions(+), 4 deletions(-)
  28
  29 --- a/drivers/net/ethernet/marvell/mvpp2.c
  30 +++ b/drivers/net/ethernet/marvell/mvpp2.c
  31 @@ -29,6 +29,7 @@
  32  #include <linux/clk.h>
  33  #include <linux/hrtimer.h>
  34  #include <linux/ktime.h>
  35 +#include <linux/if_vlan.h>
  36  #include <uapi/linux/ppp_defs.h>
  37  #include <net/ip.h>
  38  #include <net/ipv6.h>
  39 @@ -4268,7 +4269,7 @@ static void mvpp2_txq_desc_put(struct mv
  40  }
  41
  42  /* Set Tx descriptors fields relevant for CSUM calculation */
  43 -static u32 mvpp2_txq_desc_csum(int l3_offs, int l3_proto,
  44 +static u32 mvpp2_txq_desc_csum(int l3_offs, __be16 l3_proto,
  45                                int ip_hdr_len, int l4_proto)
  46  {
  47         u32 command;
  48 @@ -5032,14 +5033,15 @@ static u32 mvpp2_skb_tx_csum(struct mvpp
  49         if (skb->ip_summed == CHECKSUM_PARTIAL) {
  50                 int ip_hdr_len = 0;
  51                 u8 l4_proto;
  52 +               __be16 l3_proto = vlan_get_protocol(skb);
  53
  54 -               if (skb->protocol == htons(ETH_P_IP)) {
  55 +               if (l3_proto == htons(ETH_P_IP)) {
  56                         struct iphdr *ip4h = ip_hdr(skb);
  57
  58                         /* Calculate IPv4 checksum and L4 checksum */
  59                         ip_hdr_len = ip4h->ihl;
  60                         l4_proto = ip4h->protocol;
  61 -               } else if (skb->protocol == htons(ETH_P_IPV6)) {
  62 +               } else if (l3_proto == htons(ETH_P_IPV6)) {
  63                         struct ipv6hdr *ip6h = ipv6_hdr(skb);
  64
  65                         /* Read l4_protocol from one of IPv6 extra headers */
  66 @@ -5051,7 +5053,7 @@ static u32 mvpp2_skb_tx_csum(struct mvpp
  67                 }
  68
  69                 return mvpp2_txq_desc_csum(skb_network_offset(skb),
  70 -                               skb->protocol, ip_hdr_len, l4_proto);
  71 +                                          l3_proto, ip_hdr_len, l4_proto);
  72         }
  73
  74         return MVPP2_TXD_L4_CSUM_NOT | MVPP2_TXD_IP_CSUM_DISABLE;