fm10k: fix incorrect IPv6 extended header checksum

Check for and handle IPv6 extended headers so that Tx checksum offload
can be done. Also use skb_checksum_help for unexpected cases. This was
originally discovered in ixgbe.

Reported-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Krishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_main.c b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
index b875f42..0e166e9 100644 (file)
--- a/drivers/net/ethernet/intel/fm10k/fm10k_main.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
@@ -820,6 +820,8 @@ static void fm10k_tx_csum(struct fm10k_ring *tx_ring,
                struct ipv6hdr *ipv6;
                u8 *raw;
        } network_hdr;
+       u8 *transport_hdr;
+       __be16 frag_off;
        __be16 protocol;
        u8 l4_hdr = 0;
 
@@ -837,9 +839,11 @@ static void fm10k_tx_csum(struct fm10k_ring *tx_ring,
                        goto no_csum;
                }
                network_hdr.raw = skb_inner_network_header(skb);
+               transport_hdr = skb_inner_transport_header(skb);
        } else {
                protocol = vlan_get_protocol(skb);
                network_hdr.raw = skb_network_header(skb);
+               transport_hdr = skb_transport_header(skb);
        }
 
        switch (protocol) {
@@ -848,15 +852,17 @@ static void fm10k_tx_csum(struct fm10k_ring *tx_ring,
                break;
        case htons(ETH_P_IPV6):
                l4_hdr = network_hdr.ipv6->nexthdr;
+               if (likely((transport_hdr - network_hdr.raw) ==
+                          sizeof(struct ipv6hdr)))
+                       break;
+               ipv6_skip_exthdr(skb, network_hdr.raw - skb->data +
+                                     sizeof(struct ipv6hdr),
+                                &l4_hdr, &frag_off);
+               if (unlikely(frag_off))
+                       l4_hdr = NEXTHDR_FRAGMENT;
                break;
        default:
-               if (unlikely(net_ratelimit())) {
-                       dev_warn(tx_ring->dev,
-                                "partial checksum but ip version=%x!\n",
-                                protocol);
-               }
-               tx_ring->tx_stats.csum_err++;
-               goto no_csum;
+               break;
        }
 
        switch (l4_hdr) {
@@ -869,9 +875,10 @@ static void fm10k_tx_csum(struct fm10k_ring *tx_ring,
        default:
                if (unlikely(net_ratelimit())) {
                        dev_warn(tx_ring->dev,
-                                "partial checksum but l4 proto=%x!\n",
-                                l4_hdr);
+                                "partial checksum, version=%d l4 proto=%x\n",
+                                protocol, l4_hdr);
                }
+               skb_checksum_help(skb);
                tx_ring->tx_stats.csum_err++;
                goto no_csum;
        }