/*
* xfrm4_policy.c
*
* Changes:
* Kazunori MIYAZAWA @USAGI
* YOSHIFUJI Hideaki @USAGI
* Split up af-specific portion
*
*/
#include <linux/config.h>
#include <net/xfrm.h>
#include <net/ip.h>
static struct dst_ops xfrm4_dst_ops;
static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
static struct xfrm_type_map xfrm4_type_map = { .lock = RW_LOCK_UNLOCKED };
static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
{
return __ip_route_output_key((struct rtable**)dst, fl);
}
static struct dst_entry *
__xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
{
struct dst_entry *dst;
read_lock_bh(&policy->lock);
for (dst = policy->bundles; dst; dst = dst->next) {
struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
if (xdst->u.rt.fl.oif == fl->oif && /*XXX*/
xdst->u.rt.fl.fl4_dst == fl->fl4_dst &&
xdst->u.rt.fl.fl4_src == fl->fl4_src &&
xfrm_bundle_ok(xdst, fl, AF_INET)) {
dst_clone(dst);
break;
}
}
read_unlock_bh(&policy->lock);
return dst;
}
/* Allocate chain of dst_entry's, attach known xfrm's, calculate
* all the metrics... Shortly, bundle a bundle.
*/
static int
__xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
struct flowi *fl, struct dst_entry **dst_p)
{
struct dst_entry *dst, *dst_prev;
struct rtable *rt0 = (struct rtable*)(*dst_p);
struct rtable *rt = rt0;
u32 remote = fl->fl4_dst;
u32 local = fl->fl4_src;
struct flowi fl_tunnel = {
.nl_u = {
.ip4_u = {
.saddr = local,
.daddr = remote
}
}
};
int i;
int err;
int header_len = 0;
int trailer_len = 0;
dst = dst_prev = NULL;
dst_hold(&rt->u.dst);
for (i = 0; i < nx; i++) {
struct dst_entry *dst1 = dst_alloc(&xfrm4_dst_ops);
struct xfrm_dst *xdst;
int tunnel = 0;
if (unlikely(dst1 == NULL)) {
err = -ENOBUFS;
dst_release(&rt->u.dst);
goto error;
}
if (!dst)
dst = dst1;
else {
dst_prev->child = dst1;
dst1->flags |= DST_NOHASH;
dst_clone(dst1);
}
xdst = (struct xfrm_dst *)dst1;
xdst->route = &rt->u.dst;
dst1->next = dst_prev;
dst_prev = dst1;
if (xfrm[i]->props.mode) {
remote = xfrm[i]->id.daddr.a4;
local = xfrm[i]->props.saddr.a4;
tunnel = 1;
}
header_len += xfrm[i]->props.header_len;
trailer_len += xfrm[i]->props.trailer_len;
if (tunnel) {
fl_tunnel.fl4_src = local;
fl_tunnel.fl4_dst = remote;
err = xfrm_dst_lookup((struct xfrm_dst **)&rt,
&fl_tunnel, AF_INET);
if (err)
goto error;
} else
dst_hold(&rt->u.dst);
}
dst_prev->child = &rt->u.dst;
dst->path = &rt->u.dst;
*dst_p = dst;
dst = dst_prev;
dst_prev = *dst_p;
i = 0;
for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) {
struct xfrm_dst *x = (struct xfrm_dst*)dst_prev;
x->u.rt.fl = *fl;
dst_prev->xfrm = xfrm[i++];
dst_prev->dev = rt->u.dst.dev;
if (rt->u.dst.dev)
dev_hold(rt->u.dst.dev);
dst_prev->obsolete = -1;
dst_prev->flags |= DST_HOST;
dst_prev->lastuse = jiffies;
dst_prev->header_len = header_len;
dst_prev->trailer_len = trailer_len;
memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
/* Copy neighbout for reachability confirmation */
dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour);
dst_prev->input = rt->u.dst.input;
dst_prev->output = xfrm4_output;
if (rt->peer)
atomic_inc(&rt->peer->refcnt);
x->u.rt.peer = rt->peer;
/* Sheit... I remember I did this right. Apparently,
* it was magically lost, so this code needs audit */
x->u.rt.rt_flags = rt0->rt_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL);
x->u.rt.rt_type = rt->rt_type;
x->u.rt.rt_src = rt0->rt_src;
x->u.rt.rt_dst = rt0->rt_dst;
x->u.rt.rt_gateway = rt->rt_gateway;
x->u.rt.rt_spec_dst = rt0->rt_spec_dst;
header_len -= x->u.dst.xfrm->props.header_len;
trailer_len -= x->u.dst.xfrm->props.trailer_len;
}
xfrm_init_pmtu(dst);
return 0;
error:
if (dst)
dst_free(dst);
return err;
}
static void
_decode_session4(struct sk_buff *skb, struct flowi *fl)
{
struct iphdr *iph = skb->nh.iph;
u8 *xprth = skb->nh.raw + iph->ihl*4;
memset(fl, 0, sizeof(struct flowi));
if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
switch (iph->protocol) {
case IPPROTO_UDP:
case IPPROTO_TCP:
case IPPROTO_SCTP:
if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
u16 *ports = (u16 *)xprth;
fl->fl_ip_sport = ports[0];
fl->fl_ip_dport = ports[1];
}
break;
case IPPROTO_ICMP:
if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
u8 *icmp = xprth;
fl->fl_icmp_type = icmp[0];
fl->fl_icmp_code = icmp[1];
}
break;
case IPPROTO_ESP:
if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
u32 *ehdr = (u32 *)xprth;
fl->fl_ipsec_spi = ehdr[0];
}
break;
case IPPROTO_AH:
if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
u32 *ah_hdr = (u32*)xprth;
fl->fl_ipsec_spi = ah_hdr[1];
}
break;
case IPPROTO_COMP:
if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
u16 *ipcomp_hdr = (u16 *)xprth;
fl->fl_ipsec_spi = ntohl(ntohs(ipcomp_hdr[1]));
}
break;
default:
fl->fl_ipsec_spi = 0;
break;
};
}
fl->proto = iph->protocol;
fl->fl4_dst = iph->daddr;
fl->fl4_src = iph->saddr;
}
static inline int xfrm4_garbage_collect(void)
{
read_lock(&xfrm4_policy_afinfo.lock);
xfrm4_policy_afinfo.garbage_collect();
read_unlock(&xfrm4_policy_afinfo.lock);
return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
}
static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
{
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
struct dst_entry *path = xdst->route;
path->ops->update_pmtu(path, mtu);
}
static struct dst_ops xfrm4_dst_ops = {
.family = AF_INET,
.protocol = __constant_htons(ETH_P_IP),
.gc = xfrm4_garbage_collect,
.update_pmtu = xfrm4_update_pmtu,
.gc_thresh = 1024,
.entry_size = sizeof(struct xfrm_dst),
};
static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
.family = AF_INET,
.lock = RW_LOCK_UNLOCKED,
.type_map = &xfrm4_type_map,
.dst_ops = &xfrm4_dst_ops,
.dst_lookup = xfrm4_dst_lookup,
.find_bundle = __xfrm4_find_bundle,
.bundle_create = __xfrm4_bundle_create,
.decode_session = _decode_session4,
};
static void __init xfrm4_policy_init(void)
{
xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
}
static void __exit xfrm4_policy_fini(void)
{
xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
}
void __init xfrm4_init(void)
{
xfrm4_state_init();
xfrm4_policy_init();
}
