xfrm: gso partial offload support

This patch introduces support for gso partial ESP offload.
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Raed Salem <raeds@mellanox.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

net/ipv4/esp4_offload.c

@@ -138,9 +138,11 @@ static struct sk_buff *esp4_gso_segment(struct sk_buff *skb,
 
 	skb->encap_hdr_csum = 1;
 
-	if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev)
+	if ((!(skb->dev->gso_partial_features & NETIF_F_HW_ESP) &&
+	     !(features & NETIF_F_HW_ESP)) || x->xso.dev != skb->dev)
 		esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
-	else if (!(features & NETIF_F_HW_ESP_TX_CSUM))
+	else if (!(features & NETIF_F_HW_ESP_TX_CSUM) &&
+		 !(skb->dev->gso_partial_features & NETIF_F_HW_ESP_TX_CSUM))
 		esp_features = features & ~NETIF_F_CSUM_MASK;
 
 	xo->flags |= XFRM_GSO_SEGMENT;
@@ -181,7 +183,9 @@ static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb,  netdev_features_
 	if (!xo)
 		return -EINVAL;
 
-	if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) {
+	if ((!(features & NETIF_F_HW_ESP) &&
+	     !(skb->dev->gso_partial_features & NETIF_F_HW_ESP)) ||
+	    x->xso.dev != skb->dev) {
 		xo->flags |= CRYPTO_FALLBACK;
 		hw_offload = false;
 	}

net/xfrm/xfrm_device.c

@@ -78,6 +78,7 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur
 	}
 
 	if (!skb->next) {
+		esp_features |= skb->dev->gso_partial_features;
 		x->outer_mode->xmit(x, skb);
 
 		xo->flags |= XFRM_DEV_RESUME;
@@ -101,6 +102,8 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur
 
 	do {
 		struct sk_buff *nskb = skb2->next;
+
+		esp_features |= skb->dev->gso_partial_features;
 		skb_mark_not_on_list(skb2);
 
 		xo = xfrm_offload(skb2);