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/*
* xfrm6_input.c: based on net/ipv4/xfrm4_input.c
*
* Authors:
* Mitsuru KANDA @USAGI
* Kazunori MIYAZAWA @USAGI
* Kunihiro Ishiguro <kunihiro@ipinfusion.com>
* YOSHIFUJI Hideaki @USAGI
* IPv6 support
*/
#include <linux/module.h>
#include <linux/string.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
#include <net/dsfield.h>
#include <net/inet_ecn.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/xfrm.h>
static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
{
struct ipv6hdr *outer_iph = skb->nh.ipv6h;
struct ipv6hdr *inner_iph = skb->h.ipv6h;
if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
IP6_ECN_set_ce(inner_iph);
}
int xfrm6_rcv_spi(struct sk_buff *skb, u32 spi)
{
int err;
u32 seq;
struct sec_decap_state xfrm_vec[XFRM_MAX_DEPTH];
struct xfrm_state *x;
int xfrm_nr = 0;
int decaps = 0;
int nexthdr;
unsigned int nhoff;
nhoff = IP6CB(skb)->nhoff;
nexthdr = skb->nh.raw[nhoff];
seq = 0;
if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0)
goto drop;
do {
struct ipv6hdr *iph = skb->nh.ipv6h;
if (xfrm_nr == XFRM_MAX_DEPTH)
goto drop;
x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, nexthdr, AF_INET6);
if (x == NULL)
goto drop;
spin_lock(&x->lock);
if (unlikely(x->km.state != XFRM_STATE_VALID))
goto drop_unlock;
if (x->props.replay_window && xfrm_replay_check(x, seq))
goto drop_unlock;
if (xfrm_state_check_expire(x))
goto drop_unlock;
nexthdr = x->type->input(x, &(xfrm_vec[xfrm_nr].decap), skb);
if (nexthdr <= 0)
goto drop_unlock;
skb->nh.raw[nhoff] = nexthdr;
if (x->props.replay_window)
xfrm_replay_advance(x, seq);
x->curlft.bytes += skb->len;
x->curlft.packets++;
spin_unlock(&x->lock);
xfrm_vec[xfrm_nr++].xvec = x;
if (x->props.mode) { /* XXX */
if (nexthdr != IPPROTO_IPV6)
goto drop;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto drop;
if (skb_cloned(skb) &&
pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
goto drop;
if (x->props.flags & XFRM_STATE_DECAP_DSCP)
ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
if (!(x->props.flags & XFRM_STATE_NOECN))
ipip6_ecn_decapsulate(skb);
skb->mac.raw = memmove(skb->data - skb->mac_len,
skb->mac.raw, skb->mac_len);
skb->nh.raw = skb->data;
decaps = 1;
break;
}
if ((err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) < 0)
goto drop;
} while (!err);
/* Allocate new secpath or COW existing one. */
if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
struct sec_path *sp;
sp = secpath_dup(skb->sp);
if (!sp)
goto drop;
if (skb->sp)
secpath_put(skb->sp);
skb->sp = sp;
}
if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH)
goto drop;
memcpy(skb->sp->x+skb->sp->len, xfrm_vec, xfrm_nr*sizeof(struct sec_decap_state));
skb->sp->len += xfrm_nr;
skb->ip_summed = CHECKSUM_NONE;
nf_reset(skb);
if (decaps) {
if (!(skb->dev->flags&IFF_LOOPBACK)) {
dst_release(skb->dst);
skb->dst = NULL;
}
netif_rx(skb);
return -1;
} else {
#ifdef CONFIG_NETFILTER
skb->nh.ipv6h->payload_len = htons(skb->len);
__skb_push(skb, skb->data - skb->nh.raw);
NF_HOOK(PF_INET6, NF_IP6_PRE_ROUTING, skb, skb->dev, NULL,
ip6_rcv_finish);
return -1;
#else
return 1;
#endif
}
drop_unlock:
spin_unlock(&x->lock);
xfrm_state_put(x);
drop:
while (--xfrm_nr >= 0)
xfrm_state_put(xfrm_vec[xfrm_nr].xvec);
kfree_skb(skb);
return -1;
}
EXPORT_SYMBOL(xfrm6_rcv_spi);
int xfrm6_rcv(struct sk_buff **pskb)
{
return xfrm6_rcv_spi(*pskb, 0);
}
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