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; }