static void sn_set_tx_metadata(struct sk_buff *skb,
struct sn_tx_metadata *tx_meta)
{
if (skb->ip_summed == CHECKSUM_PARTIAL) {
tx_meta->csum_start = skb_checksum_start_offset(skb);
tx_meta->csum_dest = tx_meta->csum_start + skb->csum_offset;
} else {
tx_meta->csum_start = SN_TX_CSUM_DONT;
tx_meta->csum_dest = SN_TX_CSUM_DONT;
}
}
static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
netdev_features_t features)
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
unsigned int mss;
int offset;
__wsum csum;
if (skb->encapsulation &&
skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL) {
segs = skb_udp_tunnel_segment(skb, features);
goto out;
}
mss = skb_shinfo(skb)->gso_size;
if (unlikely(skb->len <= mss))
goto out;
if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
/* Packet is from an untrusted source, reset gso_segs. */
int type = skb_shinfo(skb)->gso_type;
if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY |
SKB_GSO_UDP_TUNNEL |
SKB_GSO_GRE | SKB_GSO_MPLS) ||
!(type & (SKB_GSO_UDP))))
goto out;
skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
segs = NULL;
goto out;
}
/* Do software UFO. Complete and fill in the UDP checksum as
* HW cannot do checksum of UDP packets sent as multiple
* IP fragments.
*/
offset = skb_checksum_start_offset(skb);
csum = skb_checksum(skb, offset, skb->len - offset, 0);
offset += skb->csum_offset;
*(__sum16 *)(skb->data + offset) = csum_fold(csum);
skb->ip_summed = CHECKSUM_NONE;
/* Fragment the skb. IP headers of the fragments are updated in
* inet_gso_segment()
*/
segs = skb_segment(skb, features);
out:
return segs;
}
