i40e/i40evf: Drop outer checksum offload that was not requested

Orabug: 22342532

The i40e and i40evf drivers contained code for inserting an outer checksum
on UDP tunnels.  The issue however is that the upper levels of the stack
never requested such an offload and it results in possible errors.

In addition the same logic was being applied to the Rx side where it was
attempting to validate the outer checksum, but the logic there was
incorrect in that it was testing for the resultant sum to be equal to the
header checksum instead of being equal to 0.

Since this code is so massively flawed, and doing things that we didn't ask
for it to do I am just dropping it, and will bring it back later to use as
an offload for SKB_GSO_UDP_TUNNEL_CSUM which can make use of such a
feature.

As far as the Rx feature I am dropping it completely since it would need to
be massively expanded and applied to IPv4 and IPv6 checksums for all parts,
not just the one that supports Tx checksum offload for the outer.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit a9c9a81f5892eb984234223399ee624f7dbd15e8)
Signed-off-by: Brian Maly <brian.maly@oracle.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index b099c5be55784b69cc5476798b905426394b1b90..f5240afe9a8c8ac6f443c66246d4337271a6ff2f 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -7420,8 +7420,6 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi)
                tx_ring->dcb_tc = 0;
                if (vsi->back->flags & I40E_FLAG_WB_ON_ITR_CAPABLE)
                        tx_ring->flags = I40E_TXR_FLAGS_WB_ON_ITR;
-               if (vsi->back->flags & I40E_FLAG_OUTER_UDP_CSUM_CAPABLE)
-                       tx_ring->flags |= I40E_TXR_FLAGS_OUTER_UDP_CSUM;
                vsi->tx_rings[i] = tx_ring;
 
                rx_ring = &tx_ring[1];

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 53f634074bd0f3b37044dbb82a478958eb52d4f5..839bfa6ac76b2e650d764b108b8780547bd2e977 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -1391,9 +1391,6 @@ static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
        struct i40e_rx_ptype_decoded decoded = decode_rx_desc_ptype(rx_ptype);
        bool ipv4 = false, ipv6 = false;
        bool ipv4_tunnel, ipv6_tunnel;
-       __wsum rx_udp_csum;
-       struct iphdr *iph;
-       __sum16 csum;
 
        ipv4_tunnel = (rx_ptype >= I40E_RX_PTYPE_GRENAT4_MAC_PAY3) &&
                     (rx_ptype <= I40E_RX_PTYPE_GRENAT4_MACVLAN_IPV6_ICMP_PAY4);
@@ -1443,37 +1440,12 @@ static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
        if (rx_error & BIT(I40E_RX_DESC_ERROR_PPRS_SHIFT))
                return;
 
-       /* If VXLAN/GENEVE traffic has an outer UDPv4 checksum we need to check
-        * it in the driver, hardware does not do it for us.
-        * Since L3L4P bit was set we assume a valid IHL value (>=5)
-        * so the total length of IPv4 header is IHL*4 bytes
-        * The UDP_0 bit *may* bet set if the *inner* header is UDP
+       /* The hardware supported by this driver does not validate outer
+        * checksums for tunneled VXLAN or GENEVE frames.  I don't agree
+        * with it but the specification states that you "MAY validate", it
+        * doesn't make it a hard requirement so if we have validated the
+        * inner checksum report CHECKSUM_UNNECESSARY.
         */
-       if (!(vsi->back->flags & I40E_FLAG_OUTER_UDP_CSUM_CAPABLE) &&
-           (ipv4_tunnel)) {
-               skb->transport_header = skb->mac_header +
-                                       sizeof(struct ethhdr) +
-                                       (ip_hdr(skb)->ihl * 4);
-
-               /* Add 4 bytes for VLAN tagged packets */
-               skb->transport_header += (skb->protocol == htons(ETH_P_8021Q) ||
-                                         skb->protocol == htons(ETH_P_8021AD))
-                                         ? VLAN_HLEN : 0;
-
-               if ((ip_hdr(skb)->protocol == IPPROTO_UDP) &&
-                   (udp_hdr(skb)->check != 0)) {
-                       rx_udp_csum = udp_csum(skb);
-                       iph = ip_hdr(skb);
-                       csum = csum_tcpudp_magic(
-                                       iph->saddr, iph->daddr,
-                                       (skb->len - skb_transport_offset(skb)),
-                                       IPPROTO_UDP, rx_udp_csum);
-
-                       if (udp_hdr(skb)->check != csum)
-                               goto checksum_fail;
-
-               } /* else its GRE and so no outer UDP header */
-       }
 
        skb->ip_summed = CHECKSUM_UNNECESSARY;
        skb->csum_level = ipv4_tunnel || ipv6_tunnel;
@@ -2452,15 +2424,6 @@ static void i40e_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags,
                        *tx_flags &= ~I40E_TX_FLAGS_IPV4;
                        *tx_flags |= I40E_TX_FLAGS_IPV6;
                }
-               if ((tx_ring->flags & I40E_TXR_FLAGS_OUTER_UDP_CSUM) &&
-                   (l4_tunnel == I40E_TXD_CTX_UDP_TUNNELING)        &&
-                   (*cd_tunneling & I40E_TXD_CTX_QW0_EXT_IP_MASK)) {
-                       oudph->check = ~csum_tcpudp_magic(oiph->saddr,
-                                       oiph->daddr,
-                                       (skb->len - skb_transport_offset(skb)),
-                                       IPPROTO_UDP, 0);
-                       *cd_tunneling |= I40E_TXD_CTX_QW0_L4T_CS_MASK;
-               }
        } else {
                network_hdr_len = skb_network_header_len(skb);
                this_ip_hdr = ip_hdr(skb);

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index 3acc9244134d9609da0b16f34c4fe5788e741498..fb065d4fe15cddee8ef1265ff39a96b20fe01a4e 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -277,7 +277,6 @@ struct i40e_ring {
 
        u16 flags;
 #define I40E_TXR_FLAGS_WB_ON_ITR       BIT(0)
-#define I40E_TXR_FLAGS_OUTER_UDP_CSUM  BIT(1)
 #define I40E_TXR_FLAGS_LAST_XMIT_MORE_SET BIT(2)
 
        /* stats structs */

diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index 46f6a65afc812250c7028aa3f0f5cd5555dfa635..a8c716b1ff3f551f99f663fc17f2a8e88785ee40 100644 (file)
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -863,9 +863,6 @@ static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
        struct i40e_rx_ptype_decoded decoded = decode_rx_desc_ptype(rx_ptype);
        bool ipv4 = false, ipv6 = false;
        bool ipv4_tunnel, ipv6_tunnel;
-       __wsum rx_udp_csum;
-       struct iphdr *iph;
-       __sum16 csum;
 
        ipv4_tunnel = (rx_ptype >= I40E_RX_PTYPE_GRENAT4_MAC_PAY3) &&
                     (rx_ptype <= I40E_RX_PTYPE_GRENAT4_MACVLAN_IPV6_ICMP_PAY4);
@@ -915,36 +912,12 @@ static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
        if (rx_error & BIT(I40E_RX_DESC_ERROR_PPRS_SHIFT))
                return;
 
-       /* If VXLAN traffic has an outer UDPv4 checksum we need to check
-        * it in the driver, hardware does not do it for us.
-        * Since L3L4P bit was set we assume a valid IHL value (>=5)
-        * so the total length of IPv4 header is IHL*4 bytes
-        * The UDP_0 bit *may* bet set if the *inner* header is UDP
+       /* The hardware supported by this driver does not validate outer
+        * checksums for tunneled VXLAN or GENEVE frames.  I don't agree
+        * with it but the specification states that you "MAY validate", it
+        * doesn't make it a hard requirement so if we have validated the
+        * inner checksum report CHECKSUM_UNNECESSARY.
         */
-       if (ipv4_tunnel) {
-               skb->transport_header = skb->mac_header +
-                                       sizeof(struct ethhdr) +
-                                       (ip_hdr(skb)->ihl * 4);
-
-               /* Add 4 bytes for VLAN tagged packets */
-               skb->transport_header += (skb->protocol == htons(ETH_P_8021Q) ||
-                                         skb->protocol == htons(ETH_P_8021AD))
-                                         ? VLAN_HLEN : 0;
-
-               if ((ip_hdr(skb)->protocol == IPPROTO_UDP) &&
-                   (udp_hdr(skb)->check != 0)) {
-                       rx_udp_csum = udp_csum(skb);
-                       iph = ip_hdr(skb);
-                       csum = csum_tcpudp_magic(iph->saddr, iph->daddr,
-                                                (skb->len -
-                                                 skb_transport_offset(skb)),
-                                                IPPROTO_UDP, rx_udp_csum);
-
-                       if (udp_hdr(skb)->check != csum)
-                               goto checksum_fail;
-
-               } /* else its GRE and so no outer UDP header */
-       }
 
        skb->ip_summed = CHECKSUM_UNNECESSARY;
        skb->csum_level = ipv4_tunnel || ipv6_tunnel;
@@ -1666,15 +1639,6 @@ static void i40e_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags,
                        *tx_flags |= I40E_TX_FLAGS_IPV6;
                }
 
-               if ((tx_ring->flags & I40E_TXR_FLAGS_OUTER_UDP_CSUM) &&
-                   (l4_tunnel == I40E_TXD_CTX_UDP_TUNNELING)        &&
-                   (*cd_tunneling & I40E_TXD_CTX_QW0_EXT_IP_MASK)) {
-                       oudph->check = ~csum_tcpudp_magic(oiph->saddr,
-                                       oiph->daddr,
-                                       (skb->len - skb_transport_offset(skb)),
-                                       IPPROTO_UDP, 0);
-                       *cd_tunneling |= I40E_TXD_CTX_QW0_L4T_CS_MASK;
-               }
        } else {
                network_hdr_len = skb_network_header_len(skb);
                this_ip_hdr = ip_hdr(skb);

diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
index 81c96619287bc45f2abc6e06c33c3404e07e6ede..043b9556834f5fe3b8ba836e234d77e3a5b46dbe 100644 (file)
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
@@ -275,7 +275,6 @@ struct i40e_ring {
 
        u16 flags;
 #define I40E_TXR_FLAGS_WB_ON_ITR       BIT(0)
-#define I40E_TXR_FLAGS_OUTER_UDP_CSUM  BIT(1)
 
        /* stats structs */
        struct i40e_queue_stats stats;