LXR linux/net/ipv4/xfrm4

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * xfrm4_output.c - Common IPsec encapsulation code for IPv4.
   4 * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
   5 */
   6
   7#include <linux/if_ether.h>
   8#include <linux/kernel.h>
   9#include <linux/module.h>
  10#include <linux/skbuff.h>
  11#include <linux/netfilter_ipv4.h>
  12#include <net/dst.h>
  13#include <net/ip.h>
  14#include <net/xfrm.h>
  15#include <net/icmp.h>
  16
  17static int __xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
  18{
  19#ifdef CONFIG_NETFILTER
  20        struct xfrm_state *x = skb_dst(skb)->xfrm;
  21
  22        if (!x) {
  23                IPCB(skb)->flags |= IPSKB_REROUTED;
  24                return dst_output(net, sk, skb);
  25        }
  26#endif
  27
  28        return xfrm_output(sk, skb);
  29}
  30
  31int xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
  32{
  33        return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
  34                            net, sk, skb, skb->dev, skb_dst(skb)->dev,
  35                            __xfrm4_output,
  36                            !(IPCB(skb)->flags & IPSKB_REROUTED));
  37}
  38
  39void xfrm4_local_error(struct sk_buff *skb, u32 mtu)
  40{
  41        struct iphdr *hdr;
  42
  43        hdr = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
  44        ip_local_error(skb->sk, EMSGSIZE, hdr->daddr,
  45                       inet_sk(skb->sk)->inet_dport, mtu);
  46}
  47