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/*
* xfrm6_output.c - Common IPsec encapsulation code for IPv6.
* Copyright (C) 2002 USAGI/WIDE Project
* 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/skbuff.h>
#include <linux/spinlock.h>
#include <linux/icmpv6.h>
#include <linux/netfilter_ipv6.h>
#include <net/ipv6.h>
#include <net/xfrm.h>
static int xfrm6_tunnel_check_size(struct sk_buff *skb)
{
int mtu, ret = 0;
struct dst_entry *dst = skb->dst;
mtu = dst_mtu(dst);
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
if (skb->len > mtu) {
skb->dev = dst->dev;
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
ret = -EMSGSIZE;
}
return ret;
}
static int xfrm6_output_one(struct sk_buff *skb)
{
struct dst_entry *dst = skb->dst;
struct xfrm_state *x = dst->xfrm;
int err;
if (skb->ip_summed == CHECKSUM_HW) {
err = skb_checksum_help(skb, 0);
if (err)
goto error_nolock;
}
if (x->props.mode) {
err = xfrm6_tunnel_check_size(skb);
if (err)
goto error_nolock;
}
do {
spin_lock_bh(&x->lock);
err = xfrm_state_check(x, skb);
if (err)
goto error;
err = x->mode->output(skb);
if (err)
goto error;
err = x->type->output(x, skb);
if (err)
goto error;
x->curlft.bytes += skb->len;
x->curlft.packets++;
spin_unlock_bh(&x->lock);
skb->nh.raw = skb->data;
if (!(skb->dst = dst_pop(dst))) {
err = -EHOSTUNREACH;
goto error_nolock;
}
dst = skb->dst;
x = dst->xfrm;
} while (x && !x->props.mode);
IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
err = 0;
out_exit:
return err;
error:
spin_unlock_bh(&x->lock);
error_nolock:
kfree_skb(skb);
goto out_exit;
}
static int xfrm6_output_finish2(struct sk_buff *skb)
{
int err;
while (likely((err = xfrm6_output_one(skb)) == 0)) {
nf_reset(skb);
err = nf_hook(PF_INET6, NF_IP6_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_INET6, NF_IP6_POST_ROUTING, &skb, NULL,
skb->dst->dev, xfrm6_output_finish2);
if (unlikely(err != 1))
break;
}
return err;
}
static int xfrm6_output_finish(struct sk_buff *skb)
{
struct sk_buff *segs;
if (!skb_is_gso(skb))
return xfrm6_output_finish2(skb);
skb->protocol = htons(ETH_P_IPV6);
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 = xfrm6_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 xfrm6_output(struct sk_buff *skb)
{
return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb, NULL, skb->dst->dev,
xfrm6_output_finish);
}
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