169 lines
3.2 KiB
C
169 lines
3.2 KiB
C
/*
|
|
* xfrm4_input.c
|
|
*
|
|
* Changes:
|
|
* YOSHIFUJI Hideaki @USAGI
|
|
* Split up af-specific portion
|
|
* Derek Atkins <derek@ihtfp.com>
|
|
* Add Encapsulation support
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/string.h>
|
|
#include <linux/netfilter.h>
|
|
#include <linux/netfilter_ipv4.h>
|
|
#include <net/ip.h>
|
|
#include <net/xfrm.h>
|
|
|
|
int xfrm4_rcv(struct sk_buff *skb)
|
|
{
|
|
return xfrm4_rcv_encap(skb, 0);
|
|
}
|
|
|
|
EXPORT_SYMBOL(xfrm4_rcv);
|
|
|
|
static int xfrm4_parse_spi(struct sk_buff *skb, u8 nexthdr, u32 *spi, u32 *seq)
|
|
{
|
|
switch (nexthdr) {
|
|
case IPPROTO_IPIP:
|
|
*spi = skb->nh.iph->saddr;
|
|
*seq = 0;
|
|
return 0;
|
|
}
|
|
|
|
return xfrm_parse_spi(skb, nexthdr, spi, seq);
|
|
}
|
|
|
|
#ifdef CONFIG_NETFILTER
|
|
static inline int xfrm4_rcv_encap_finish(struct sk_buff *skb)
|
|
{
|
|
struct iphdr *iph = skb->nh.iph;
|
|
|
|
if (skb->dst == NULL) {
|
|
if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos,
|
|
skb->dev))
|
|
goto drop;
|
|
}
|
|
return dst_input(skb);
|
|
drop:
|
|
kfree_skb(skb);
|
|
return NET_RX_DROP;
|
|
}
|
|
#endif
|
|
|
|
int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
|
|
{
|
|
int err;
|
|
u32 spi, seq;
|
|
struct xfrm_state *xfrm_vec[XFRM_MAX_DEPTH];
|
|
struct xfrm_state *x;
|
|
int xfrm_nr = 0;
|
|
int decaps = 0;
|
|
|
|
if ((err = xfrm4_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) != 0)
|
|
goto drop;
|
|
|
|
do {
|
|
struct iphdr *iph = skb->nh.iph;
|
|
|
|
if (xfrm_nr == XFRM_MAX_DEPTH)
|
|
goto drop;
|
|
|
|
x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, iph->protocol, AF_INET);
|
|
if (x == NULL)
|
|
goto drop;
|
|
|
|
spin_lock(&x->lock);
|
|
if (unlikely(x->km.state != XFRM_STATE_VALID))
|
|
goto drop_unlock;
|
|
|
|
if ((x->encap ? x->encap->encap_type : 0) != encap_type)
|
|
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;
|
|
|
|
if (x->type->input(x, skb))
|
|
goto drop_unlock;
|
|
|
|
/* only the first xfrm gets the encap type */
|
|
encap_type = 0;
|
|
|
|
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++] = x;
|
|
|
|
if (x->mode->input(x, skb))
|
|
goto drop;
|
|
|
|
if (x->props.mode) {
|
|
decaps = 1;
|
|
break;
|
|
}
|
|
|
|
if ((err = xfrm_parse_spi(skb, skb->nh.iph->protocol, &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->xvec + skb->sp->len, xfrm_vec,
|
|
xfrm_nr * sizeof(xfrm_vec[0]));
|
|
skb->sp->len += xfrm_nr;
|
|
|
|
nf_reset(skb);
|
|
|
|
if (decaps) {
|
|
if (!(skb->dev->flags&IFF_LOOPBACK)) {
|
|
dst_release(skb->dst);
|
|
skb->dst = NULL;
|
|
}
|
|
netif_rx(skb);
|
|
return 0;
|
|
} else {
|
|
#ifdef CONFIG_NETFILTER
|
|
__skb_push(skb, skb->data - skb->nh.raw);
|
|
skb->nh.iph->tot_len = htons(skb->len);
|
|
ip_send_check(skb->nh.iph);
|
|
|
|
NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, skb->dev, NULL,
|
|
xfrm4_rcv_encap_finish);
|
|
return 0;
|
|
#else
|
|
return -skb->nh.iph->protocol;
|
|
#endif
|
|
}
|
|
|
|
drop_unlock:
|
|
spin_unlock(&x->lock);
|
|
xfrm_state_put(x);
|
|
drop:
|
|
while (--xfrm_nr >= 0)
|
|
xfrm_state_put(xfrm_vec[xfrm_nr]);
|
|
|
|
kfree_skb(skb);
|
|
return 0;
|
|
}
|