net/xfrm: Add inner_ipproto into sec_path

The inner_ipproto saves the inner IP protocol of the plain
text packet. This allows vendor's IPsec feature making offload
decision at skb's features_check and configuring hardware at
ndo_start_xmit.

For example, ConnectX6-DX IPsec device needs the plaintext's
IP protocol to support partial checksum offload on
VXLAN/GENEVE packet over IPsec transport mode tunnel.

Signed-off-by: Raed Salem <raeds@nvidia.com>
Signed-off-by: Huy Nguyen <huyn@nvidia.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index c58a6d4..1d803e8 100644 (file)
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1024,6 +1024,7 @@ struct xfrm_offload {
 #define CRYPTO_INVALID_PROTOCOL                        128
 
        __u8                    proto;
+       __u8                    inner_ipproto;
 };
 
 struct sec_path {

diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index e4cb0ff..e321fc6 100644 (file)
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -565,6 +565,42 @@ static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb
        return 0;
 }
 
+/* For partial checksum offload, the outer header checksum is calculated
+ * by software and the inner header checksum is calculated by hardware.
+ * This requires hardware to know the inner packet type to calculate
+ * the inner header checksum. Save inner ip protocol here to avoid
+ * traversing the packet in the vendor's xmit code.
+ * If the encap type is IPIP, just save skb->inner_ipproto. Otherwise,
+ * get the ip protocol from the IP header.
+ */
+static void xfrm_get_inner_ipproto(struct sk_buff *skb)
+{
+       struct xfrm_offload *xo = xfrm_offload(skb);
+       const struct ethhdr *eth;
+
+       if (!xo)
+               return;
+
+       if (skb->inner_protocol_type == ENCAP_TYPE_IPPROTO) {
+               xo->inner_ipproto = skb->inner_ipproto;
+               return;
+       }
+
+       if (skb->inner_protocol_type != ENCAP_TYPE_ETHER)
+               return;
+
+       eth = (struct ethhdr *)skb_inner_mac_header(skb);
+
+       switch (ntohs(eth->h_proto)) {
+       case ETH_P_IPV6:
+               xo->inner_ipproto = inner_ipv6_hdr(skb)->nexthdr;
+               break;
+       case ETH_P_IP:
+               xo->inner_ipproto = inner_ip_hdr(skb)->protocol;
+               break;
+       }
+}
+
 int xfrm_output(struct sock *sk, struct sk_buff *skb)
 {
        struct net *net = dev_net(skb_dst(skb)->dev);
@@ -594,12 +630,15 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
                        kfree_skb(skb);
                        return -ENOMEM;
                }
-               skb->encapsulation = 1;
 
                sp->olen++;
                sp->xvec[sp->len++] = x;
                xfrm_state_hold(x);
 
+               if (skb->encapsulation)
+                       xfrm_get_inner_ipproto(skb);
+               skb->encapsulation = 1;
+
                if (skb_is_gso(skb)) {
                        if (skb->inner_protocol)
                                return xfrm_output_gso(net, sk, skb);