mirror of https://gitee.com/openkylin/linux.git
146 lines
2.9 KiB
C
146 lines
2.9 KiB
C
/*
|
|
* xfrm4_output.c - Common IPsec encapsulation code for IPv4.
|
|
* Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/if_ether.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/netfilter_ipv4.h>
|
|
#include <net/ip.h>
|
|
#include <net/xfrm.h>
|
|
#include <net/icmp.h>
|
|
|
|
static int xfrm4_tunnel_check_size(struct sk_buff *skb)
|
|
{
|
|
int mtu, ret = 0;
|
|
struct dst_entry *dst;
|
|
|
|
if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
|
|
goto out;
|
|
|
|
IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
|
|
|
|
if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->local_df)
|
|
goto out;
|
|
|
|
dst = skb->dst;
|
|
mtu = dst_mtu(dst);
|
|
if (skb->len > mtu) {
|
|
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
|
|
ret = -EMSGSIZE;
|
|
}
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static inline int xfrm4_output_one(struct sk_buff *skb)
|
|
{
|
|
struct dst_entry *dst = skb->dst;
|
|
struct xfrm_state *x = dst->xfrm;
|
|
struct iphdr *iph;
|
|
int err;
|
|
|
|
if (x->props.mode == XFRM_MODE_TUNNEL) {
|
|
err = xfrm4_tunnel_check_size(skb);
|
|
if (err)
|
|
goto error_nolock;
|
|
}
|
|
|
|
err = xfrm_output(skb);
|
|
if (err)
|
|
goto error_nolock;
|
|
|
|
iph = ip_hdr(skb);
|
|
iph->tot_len = htons(skb->len);
|
|
ip_send_check(iph);
|
|
|
|
IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
|
|
err = 0;
|
|
|
|
out_exit:
|
|
return err;
|
|
error_nolock:
|
|
kfree_skb(skb);
|
|
goto out_exit;
|
|
}
|
|
|
|
static int xfrm4_output_finish2(struct sk_buff *skb)
|
|
{
|
|
int err;
|
|
|
|
while (likely((err = xfrm4_output_one(skb)) == 0)) {
|
|
nf_reset(skb);
|
|
|
|
err = nf_hook(PF_INET, NF_IP_LOCAL_OUT, skb, NULL,
|
|
skb->dst->dev, dst_output);
|
|
if (unlikely(err != 1))
|
|
break;
|
|
|
|
if (!skb->dst->xfrm)
|
|
return dst_output(skb);
|
|
|
|
err = nf_hook(PF_INET, NF_IP_POST_ROUTING, skb, NULL,
|
|
skb->dst->dev, xfrm4_output_finish2);
|
|
if (unlikely(err != 1))
|
|
break;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int xfrm4_output_finish(struct sk_buff *skb)
|
|
{
|
|
struct sk_buff *segs;
|
|
|
|
#ifdef CONFIG_NETFILTER
|
|
if (!skb->dst->xfrm) {
|
|
IPCB(skb)->flags |= IPSKB_REROUTED;
|
|
return dst_output(skb);
|
|
}
|
|
#endif
|
|
|
|
if (!skb_is_gso(skb))
|
|
return xfrm4_output_finish2(skb);
|
|
|
|
skb->protocol = htons(ETH_P_IP);
|
|
segs = skb_gso_segment(skb, 0);
|
|
kfree_skb(skb);
|
|
if (unlikely(IS_ERR(segs)))
|
|
return PTR_ERR(segs);
|
|
|
|
do {
|
|
struct sk_buff *nskb = segs->next;
|
|
int err;
|
|
|
|
segs->next = NULL;
|
|
err = xfrm4_output_finish2(segs);
|
|
|
|
if (unlikely(err)) {
|
|
while ((segs = nskb)) {
|
|
nskb = segs->next;
|
|
segs->next = NULL;
|
|
kfree_skb(segs);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
segs = nskb;
|
|
} while (segs);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int xfrm4_output(struct sk_buff *skb)
|
|
{
|
|
return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dst->dev,
|
|
xfrm4_output_finish,
|
|
!(IPCB(skb)->flags & IPSKB_REROUTED));
|
|
}
|