bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
{
int mtu;
struct dst_entry *dst = skb_dst(skb);
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
struct net_device *dev = x->xso.dev;
if (!x->type_offload || x->encap)
return false;
if ((x->xso.offload_handle && (dev == dst->path->dev)) &&
!dst->child->xfrm && x->type->get_mtu) {
mtu = x->type->get_mtu(x, xdst->child_mtu_cached);
if (skb->len <= mtu)
goto ok;
if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
goto ok;
}
return false;
ok:
if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok)
return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x);
return true;
}
/* Based on ip_exceeds_mtu(). */
static bool __nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
{
if (skb->len <= mtu)
return false;
if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
return false;
return true;
}
static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
{
if (skb->len <= mtu)
return false;
/* ipv6 conntrack defrag sets max_frag_size + ignore_df */
if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
return true;
if (skb->ignore_df)
return false;
if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
return false;
return true;
}
static bool ip_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
{
if (skb->len <= mtu)
return false;
if (unlikely((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0))
return false;
/* original fragment exceeds mtu and DF is set */
if (unlikely(IPCB(skb)->frag_max_size > mtu))
return true;
if (skb->ignore_df)
return false;
if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
return false;
return true;
}
