vxlan: Use checksum partial with remote checksum offload

Change remote checksum handling to set checksum partial as default
behavior. Added an iflink parameter to configure not using
checksum partial (calling csum_partial to update checksum).

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 23 insertions, 7 deletions

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 4f04443cfd33..1e0a775ea882 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -555,7 +555,8 @@ static int vxlan_fdb_append(struct vxlan_fdb *f,
 static struct vxlanhdr *vxlan_gro_remcsum(struct sk_buff *skb,
                                           unsigned int off,
                                           struct vxlanhdr *vh, size_t hdrlen,
-                                          u32 data, struct gro_remcsum *grc)
+                                          u32 data, struct gro_remcsum *grc,
+                                          bool nopartial)
 {
         size_t start, offset, plen;
 
@@ -580,7 +581,7 @@ static struct vxlanhdr *vxlan_gro_remcsum(struct sk_buff *skb,
         }
 
         skb_gro_remcsum_process(skb, (void *)vh + hdrlen,
-                                start, offset, grc, true);
+                                start, offset, grc, nopartial);
 
         skb->remcsum_offload = 1;
 
@@ -618,7 +619,9 @@ static struct sk_buff **vxlan_gro_receive(struct sk_buff **head,
 
         if ((flags & VXLAN_HF_RCO) && (vs->flags & VXLAN_F_REMCSUM_RX)) {
                 vh = vxlan_gro_remcsum(skb, off_vx, vh, sizeof(struct vxlanhdr),
-                                       ntohl(vh->vx_vni), &grc);
+                                       ntohl(vh->vx_vni), &grc,
+                                       !!(vs->flags &
+                                          VXLAN_F_REMCSUM_NOPARTIAL));
 
                 if (!vh)
                         goto out;
@@ -1155,7 +1158,7 @@ static void vxlan_igmp_leave(struct work_struct *work)
 }
 
 static struct vxlanhdr *vxlan_remcsum(struct sk_buff *skb, struct vxlanhdr *vh,
-                                      size_t hdrlen, u32 data)
+                                      size_t hdrlen, u32 data, bool nopartial)
 {
         size_t start, offset, plen;
 
@@ -1171,7 +1174,8 @@ static struct vxlanhdr *vxlan_remcsum(struct sk_buff *skb, struct vxlanhdr *vh,
 
         vh = (struct vxlanhdr *)(udp_hdr(skb) + 1);
 
-        skb_remcsum_process(skb, (void *)vh + hdrlen, start, offset, true);
+        skb_remcsum_process(skb, (void *)vh + hdrlen, start, offset,
+                            nopartial);
 
         return vh;
 }
@@ -1208,7 +1212,8 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
                 goto drop;
 
         if ((flags & VXLAN_HF_RCO) && (vs->flags & VXLAN_F_REMCSUM_RX)) {
-                vxh = vxlan_remcsum(skb, vxh, sizeof(struct vxlanhdr), vni);
+                vxh = vxlan_remcsum(skb, vxh, sizeof(struct vxlanhdr), vni,
+                                    !!(vs->flags & VXLAN_F_REMCSUM_NOPARTIAL));
                 if (!vxh)
                         goto drop;
 
@@ -2437,6 +2442,7 @@ static const struct nla_policy vxlan_policy[IFLA_VXLAN_MAX + 1] = {
         [IFLA_VXLAN_REMCSUM_TX] = { .type = NLA_U8 },
         [IFLA_VXLAN_REMCSUM_RX] = { .type = NLA_U8 },
         [IFLA_VXLAN_GBP]        = { .type = NLA_FLAG, },
+        [IFLA_VXLAN_REMCSUM_NOPARTIAL]  = { .type = NLA_FLAG },
 };
 
 static int vxlan_validate(struct nlattr *tb[], struct nlattr *data[])
@@ -2760,6 +2766,9 @@ static int vxlan_newlink(struct net *src_net, struct net_device *dev,
         if (data[IFLA_VXLAN_GBP])
                 vxlan->flags |= VXLAN_F_GBP;
 
+        if (data[IFLA_VXLAN_REMCSUM_NOPARTIAL])
+                vxlan->flags |= VXLAN_F_REMCSUM_NOPARTIAL;
+
         if (vxlan_find_vni(src_net, vni, use_ipv6 ? AF_INET6 : AF_INET,
                            vxlan->dst_port, vxlan->flags)) {
                 pr_info("duplicate VNI %u\n", vni);
@@ -2909,6 +2918,10 @@ static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
             nla_put_flag(skb, IFLA_VXLAN_GBP))
                 goto nla_put_failure;
 
+        if (vxlan->flags & VXLAN_F_REMCSUM_NOPARTIAL &&
+            nla_put_flag(skb, IFLA_VXLAN_REMCSUM_NOPARTIAL))
+                goto nla_put_failure;
+
         return 0;
 
 nla_put_failure:
diff --git a/include/net/vxlan.h b/include/net/vxlan.h
index 2927d6244481..eabd3a038674 100644
--- a/include/net/vxlan.h
+++ b/include/net/vxlan.h
@@ -128,13 +128,15 @@ struct vxlan_sock {
 #define VXLAN_F_REMCSUM_TX              0x200
 #define VXLAN_F_REMCSUM_RX              0x400
 #define VXLAN_F_GBP                     0x800
+#define VXLAN_F_REMCSUM_NOPARTIAL       0x1000
 
 /* Flags that are used in the receive patch. These flags must match in
  * order for a socket to be shareable
  */
 #define VXLAN_F_RCV_FLAGS               (VXLAN_F_GBP |                  \
                                          VXLAN_F_UDP_ZERO_CSUM6_RX |    \
-                                         VXLAN_F_REMCSUM_RX)
+                                         VXLAN_F_REMCSUM_RX |           \
+                                         VXLAN_F_REMCSUM_NOPARTIAL)
 
 struct vxlan_sock *vxlan_sock_add(struct net *net, __be16 port,
                                   vxlan_rcv_t *rcv, void *data,
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 0deee3eeddbf..dfd0bb22e554 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -374,6 +374,7 @@ enum {
         IFLA_VXLAN_REMCSUM_TX,
         IFLA_VXLAN_REMCSUM_RX,
         IFLA_VXLAN_GBP,
+        IFLA_VXLAN_REMCSUM_NOPARTIAL,
         __IFLA_VXLAN_MAX
 };
 #define IFLA_VXLAN_MAX  (__IFLA_VXLAN_MAX - 1)