xfrm: Add encapsulation header offsets while SKB is not encrypted

Both esp4 and esp6 used to assume that the SKB payload is encrypted
and therefore the inner_network and inner_transport offsets are
not relevant.
When doing crypto offload in the NIC, this is no longer the case
and the NIC driver needs these offsets so it can do TX TCP checksum
offloading.
This patch sets the inner_network and inner_transport members of
the SKB, as well as encapsulation, to reflect the actual positions
of these headers, and removes them only once encryption is done
on the payload.

Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

5 files changed, 11 insertions, 0 deletions

diff --git a/net/ipv4/xfrm4_mode_transport.c b/net/ipv4/xfrm4_mode_transport.c
index 6c2411d09386..3d36644890bb 100644
--- a/net/ipv4/xfrm4_mode_transport.c
+++ b/net/ipv4/xfrm4_mode_transport.c
@@ -24,6 +24,8 @@ static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb)
 	struct iphdr *iph = ip_hdr(skb);
 	int ihl = iph->ihl * 4;
 
+	skb_set_inner_transport_header(skb, skb_transport_offset(skb));
+
 	skb_set_network_header(skb, -x->props.header_len);
 	skb->mac_header = skb->network_header +
 			  offsetof(struct iphdr, protocol);
diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index d3f2434fa0b8..e6265e2c274e 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -33,6 +33,9 @@ static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
 	struct iphdr *top_iph;
 	int flags;
 
+	skb_set_inner_network_header(skb, skb_network_offset(skb));
+	skb_set_inner_transport_header(skb, skb_transport_offset(skb));
+
 	skb_set_network_header(skb, -x->props.header_len);
 	skb->mac_header = skb->network_header +
 			  offsetof(struct iphdr, protocol);
diff --git a/net/ipv6/xfrm6_mode_transport.c b/net/ipv6/xfrm6_mode_transport.c
index eb9b36b06c1d..7a92c0f31912 100644
--- a/net/ipv6/xfrm6_mode_transport.c
+++ b/net/ipv6/xfrm6_mode_transport.c
@@ -27,6 +27,7 @@ static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
 	int hdr_len;
 
 	iph = ipv6_hdr(skb);
+	skb_set_inner_transport_header(skb, skb_transport_offset(skb));
 
 	hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
 	skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 19a60fc4c29b..02556e356f87 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -36,6 +36,9 @@ static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
 	struct ipv6hdr *top_iph;
 	int dsfield;
 
+	skb_set_inner_network_header(skb, skb_network_offset(skb));
+	skb_set_inner_transport_header(skb, skb_transport_offset(skb));
+
 	skb_set_network_header(skb, -x->props.header_len);
 	skb->mac_header = skb->network_header +
 			  offsetof(struct ipv6hdr, nexthdr);
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index a15088613a6c..8c0b6722aaa8 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -205,6 +205,7 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
 	int err;
 
 	secpath_reset(skb);
+	skb->encapsulation = 0;
 
 	if (xfrm_dev_offload_ok(skb, x)) {
 		struct sec_path *sp;
@@ -218,6 +219,7 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
 		if (skb->sp)
 			secpath_put(skb->sp);
 		skb->sp = sp;
+		skb->encapsulation = 1;
 
 		sp->olen++;
 		sp->xvec[skb->sp->len++] = x;