linux/net/ipv4/xfrm4_policy.c
Herbert Xu fff6938880 [IPSEC]: Make sure idev is consistent with dev in xfrm_dst
Previously we took the device from the bottom route and idev from the
top route.  This is bad because idev may well point to a different
device.  This patch changes it so that we get the idev from the device
directly.

It also makes it an error if either dev or idev is NULL.  This is
consistent with the rest of the routing code which also treats these
cases as errors.

I've removed the err initialisation in xfrm6_policy.c because it
achieves no purpose and hid a bug when an initial version of this
patch neglected to set err to -ENODEV (fortunately the IPv4 version
warned about it).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:53:40 -08:00

357 lines
8.1 KiB
C

/*
* xfrm4_policy.c
*
* Changes:
* Kazunori MIYAZAWA @USAGI
* YOSHIFUJI Hideaki @USAGI
* Split up af-specific portion
*
*/
#include <linux/compiler.h>
#include <linux/inetdevice.h>
#include <net/dst.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 int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
{
return __ip_route_output_key((struct rtable**)dst, fl);
}
static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
{
struct rtable *rt;
struct flowi fl_tunnel = {
.nl_u = {
.ip4_u = {
.daddr = daddr->a4,
},
},
};
if (!xfrm4_dst_lookup((struct xfrm_dst **)&rt, &fl_tunnel)) {
saddr->a4 = rt->rt_src;
dst_release(&rt->u.dst);
return 0;
}
return -EHOSTUNREACH;
}
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 &&
xdst->u.rt.fl.fl4_tos == fl->fl4_tos &&
xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) {
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;
struct flowi fl_tunnel = {
.nl_u = {
.ip4_u = {
.saddr = fl->fl4_src,
.daddr = fl->fl4_dst,
.tos = fl->fl4_tos
}
}
};
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;
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;
xdst->genid = xfrm[i]->genid;
dst1->next = dst_prev;
dst_prev = dst1;
header_len += xfrm[i]->props.header_len;
trailer_len += xfrm[i]->props.trailer_len;
if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
unsigned short encap_family = xfrm[i]->props.family;
switch (encap_family) {
case AF_INET:
fl_tunnel.fl4_dst = xfrm[i]->id.daddr.a4;
fl_tunnel.fl4_src = xfrm[i]->props.saddr.a4;
break;
#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
case AF_INET6:
ipv6_addr_copy(&fl_tunnel.fl6_dst, (struct in6_addr*)&xfrm[i]->id.daddr.a6);
ipv6_addr_copy(&fl_tunnel.fl6_src, (struct in6_addr*)&xfrm[i]->props.saddr.a6);
break;
#endif
default:
BUG_ON(1);
}
err = xfrm_dst_lookup((struct xfrm_dst **)&rt,
&fl_tunnel, encap_family);
if (err)
goto error;
} else
dst_hold(&rt->u.dst);
}
dst_prev->child = &rt->u.dst;
dst->path = &rt->u.dst;
/* Copy neighbout for reachability confirmation */
dst->neighbour = neigh_clone(rt->u.dst.neighbour);
*dst_p = dst;
dst = dst_prev;
dst_prev = *dst_p;
i = 0;
err = -ENODEV;
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)
goto error;
dev_hold(rt->u.dst.dev);
x->u.rt.idev = in_dev_get(rt->u.dst.dev);
if (!x->u.rt.idev)
goto error;
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));
dst_prev->input = dst_discard;
dst_prev->output = dst_prev->xfrm->outer_mode->afinfo->output;
if (rt0->peer)
atomic_inc(&rt0->peer->refcnt);
x->u.rt.peer = rt0->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 = rt0->rt_type;
x->u.rt.rt_src = rt0->rt_src;
x->u.rt.rt_dst = rt0->rt_dst;
x->u.rt.rt_gateway = rt0->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 = ip_hdr(skb);
u8 *xprth = skb_network_header(skb) + 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_UDPLITE:
case IPPROTO_TCP:
case IPPROTO_SCTP:
case IPPROTO_DCCP:
if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
__be16 *ports = (__be16 *)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)) {
__be32 *ehdr = (__be32 *)xprth;
fl->fl_ipsec_spi = ehdr[0];
}
break;
case IPPROTO_AH:
if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
__be32 *ah_hdr = (__be32*)xprth;
fl->fl_ipsec_spi = ah_hdr[1];
}
break;
case IPPROTO_COMP:
if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
__be16 *ipcomp_hdr = (__be16 *)xprth;
fl->fl_ipsec_spi = htonl(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;
fl->fl4_tos = iph->tos;
}
static inline int xfrm4_garbage_collect(void)
{
xfrm4_policy_afinfo.garbage_collect();
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 void xfrm4_dst_destroy(struct dst_entry *dst)
{
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
if (likely(xdst->u.rt.idev))
in_dev_put(xdst->u.rt.idev);
if (likely(xdst->u.rt.peer))
inet_putpeer(xdst->u.rt.peer);
xfrm_dst_destroy(xdst);
}
static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
int unregister)
{
struct xfrm_dst *xdst;
if (!unregister)
return;
xdst = (struct xfrm_dst *)dst;
if (xdst->u.rt.idev->dev == dev) {
struct in_device *loopback_idev = in_dev_get(init_net.loopback_dev);
BUG_ON(!loopback_idev);
do {
in_dev_put(xdst->u.rt.idev);
xdst->u.rt.idev = loopback_idev;
in_dev_hold(loopback_idev);
xdst = (struct xfrm_dst *)xdst->u.dst.child;
} while (xdst->u.dst.xfrm);
__in_dev_put(loopback_idev);
}
xfrm_dst_ifdown(dst, dev);
}
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,
.destroy = xfrm4_dst_destroy,
.ifdown = xfrm4_dst_ifdown,
.gc_thresh = 1024,
.entry_size = sizeof(struct xfrm_dst),
};
static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
.family = AF_INET,
.dst_ops = &xfrm4_dst_ops,
.dst_lookup = xfrm4_dst_lookup,
.get_saddr = xfrm4_get_saddr,
.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();
}