2 * xfrm4_output.c - Common IPsec encapsulation code for IPv4.
3 * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version
8 * 2 of the License, or (at your option) any later version.
11 #include <linux/compiler.h>
12 #include <linux/if_ether.h>
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/spinlock.h>
16 #include <linux/netfilter_ipv4.h>
21 extern int skb_checksum_setup(struct sk_buff *skb);
23 static int xfrm4_tunnel_check_size(struct sk_buff *skb)
26 struct dst_entry *dst;
27 struct iphdr *iph = skb->nh.iph;
29 if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
32 IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
34 if (!(iph->frag_off & htons(IP_DF)) || skb->local_df)
40 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
47 static int xfrm4_output_one(struct sk_buff *skb)
49 struct dst_entry *dst = skb->dst;
50 struct xfrm_state *x = dst->xfrm;
53 err = skb_checksum_setup(skb);
57 if (skb->ip_summed == CHECKSUM_HW) {
58 err = skb_checksum_help(skb, 0);
64 err = xfrm4_tunnel_check_size(skb);
70 spin_lock_bh(&x->lock);
71 err = xfrm_state_check(x, skb);
75 err = x->mode->output(skb);
79 err = x->type->output(x, skb);
83 x->curlft.bytes += skb->len;
86 spin_unlock_bh(&x->lock);
88 if (!(skb->dst = dst_pop(dst))) {
94 } while (x && !x->props.mode);
96 IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
102 spin_unlock_bh(&x->lock);
108 static int xfrm4_output_finish2(struct sk_buff *skb)
112 while (likely((err = xfrm4_output_one(skb)) == 0)) {
115 err = nf_hook(PF_INET, NF_IP_LOCAL_OUT, &skb, NULL,
116 skb->dst->dev, dst_output);
117 if (unlikely(err != 1))
121 return dst_output(skb);
123 err = nf_hook(PF_INET, NF_IP_POST_ROUTING, &skb, NULL,
124 skb->dst->dev, xfrm4_output_finish2);
125 if (unlikely(err != 1))
132 static int xfrm4_output_finish(struct sk_buff *skb)
134 struct sk_buff *segs;
136 #ifdef CONFIG_NETFILTER
137 if (!skb->dst->xfrm) {
138 IPCB(skb)->flags |= IPSKB_REROUTED;
139 return dst_output(skb);
143 if (!skb_is_gso(skb))
144 return xfrm4_output_finish2(skb);
146 skb->protocol = htons(ETH_P_IP);
147 segs = skb_gso_segment(skb, 0);
149 if (unlikely(IS_ERR(segs)))
150 return PTR_ERR(segs);
153 struct sk_buff *nskb = segs->next;
157 err = xfrm4_output_finish2(segs);
160 while ((segs = nskb)) {
174 int xfrm4_output(struct sk_buff *skb)
176 return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dst->dev,
178 !(IPCB(skb)->flags & IPSKB_REROUTED));