[net-next-2.6.git] / net / ipv4 / xfrm4_policy.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/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 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(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;
	u32 remote = fl->fl4_dst;
	u32 local  = fl->fl4_src;
	struct flowi fl_tunnel = {
		.nl_u = {
			.ip4_u = {
				.saddr = local,
				.daddr = remote,
				.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;
		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;
		xdst->genid = xfrm[i]->genid;

		dst1->next = dst_prev;
		dst_prev = dst1;
		if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
			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->nfheader_len	= 0;
		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;
		x->u.rt.idev = rt0->idev;
		in_dev_hold(rt0->idev);
		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:
		case IPPROTO_DCCP:
			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 = 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);
	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(&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,
	.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();
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* xfrm4_policy.c
	3	*
	4	* Changes:
	5	* Kazunori MIYAZAWA @USAGI
	6	* YOSHIFUJI Hideaki @USAGI
	7	* Split up af-specific portion
	8	*
	9	*/
	10
aabc9761	11	#include <linux/compiler.h>
aabc9761	12	#include <linux/inetdevice.h>
1da177e4 LT	13	#include <net/xfrm.h>
	14	#include <net/ip.h>
	15
	16	static struct dst_ops xfrm4_dst_ops;
	17	static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
	18
1da177e4 LT	19	static int xfrm4_dst_lookup(struct xfrm_dst *dst, struct flowi fl)
	20	{
	21	return __ip_route_output_key((struct rtable**)dst, fl);
	22	}
	23
	24	static struct dst_entry *
	25	__xfrm4_find_bundle(struct flowi fl, struct xfrm_policy policy)
	26	{
	27	struct dst_entry *dst;
	28
	29	read_lock_bh(&policy->lock);
	30	for (dst = policy->bundles; dst; dst = dst->next) {
	31	struct xfrm_dst xdst = (struct xfrm_dst)dst;
	32	if (xdst->u.rt.fl.oif == fl->oif && /XXX/
	33	xdst->u.rt.fl.fl4_dst == fl->fl4_dst &&
	34	xdst->u.rt.fl.fl4_src == fl->fl4_src &&
4da3089f	35	xdst->u.rt.fl.fl4_tos == fl->fl4_tos &&
e53820de	36	xfrm_bundle_ok(xdst, fl, AF_INET, 0)) {
1da177e4 LT	37	dst_clone(dst);
	38	break;
	39	}
	40	}
	41	read_unlock_bh(&policy->lock);
	42	return dst;
	43	}
	44
	45	/* Allocate chain of dst_entry's, attach known xfrm's, calculate
	46	* all the metrics... Shortly, bundle a bundle.
	47	*/
	48
	49	static int
	50	__xfrm4_bundle_create(struct xfrm_policy policy, struct xfrm_state *xfrm, int nx,
	51	struct flowi fl, struct dst_entry *dst_p)
	52	{
	53	struct dst_entry dst, dst_prev;
	54	struct rtable rt0 = (struct rtable)(*dst_p);
	55	struct rtable *rt = rt0;
	56	u32 remote = fl->fl4_dst;
	57	u32 local = fl->fl4_src;
	58	struct flowi fl_tunnel = {
	59	.nl_u = {
	60	.ip4_u = {
	61	.saddr = local,
4da3089f HX	62	.daddr = remote,
4da3089f HX	63	.tos = fl->fl4_tos
1da177e4 LT	64	}
	65	}
	66	};
	67	int i;
	68	int err;
	69	int header_len = 0;
	70	int trailer_len = 0;
	71
	72	dst = dst_prev = NULL;
	73	dst_hold(&rt->u.dst);
	74
	75	for (i = 0; i < nx; i++) {
	76	struct dst_entry *dst1 = dst_alloc(&xfrm4_dst_ops);
	77	struct xfrm_dst *xdst;
	78	int tunnel = 0;
	79
	80	if (unlikely(dst1 == NULL)) {
	81	err = -ENOBUFS;
	82	dst_release(&rt->u.dst);
	83	goto error;
	84	}
	85
	86	if (!dst)
	87	dst = dst1;
	88	else {
	89	dst_prev->child = dst1;
	90	dst1->flags \|= DST_NOHASH;
	91	dst_clone(dst1);
	92	}
	93
	94	xdst = (struct xfrm_dst *)dst1;
	95	xdst->route = &rt->u.dst;
9d4a706d	96	xdst->genid = xfrm[i]->genid;
1da177e4 LT	97
	98	dst1->next = dst_prev;
	99	dst_prev = dst1;
7e49e6de	100	if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
1da177e4 LT	101	remote = xfrm[i]->id.daddr.a4;
	102	local = xfrm[i]->props.saddr.a4;
	103	tunnel = 1;
	104	}
	105	header_len += xfrm[i]->props.header_len;
	106	trailer_len += xfrm[i]->props.trailer_len;
	107
	108	if (tunnel) {
	109	fl_tunnel.fl4_src = local;
	110	fl_tunnel.fl4_dst = remote;
	111	err = xfrm_dst_lookup((struct xfrm_dst **)&rt,
	112	&fl_tunnel, AF_INET);
	113	if (err)
	114	goto error;
	115	} else
	116	dst_hold(&rt->u.dst);
	117	}
	118
	119	dst_prev->child = &rt->u.dst;
	120	dst->path = &rt->u.dst;
	121
	122	*dst_p = dst;
	123	dst = dst_prev;
	124
	125	dst_prev = *dst_p;
	126	i = 0;
	127	for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) {
	128	struct xfrm_dst x = (struct xfrm_dst)dst_prev;
	129	x->u.rt.fl = *fl;
	130
	131	dst_prev->xfrm = xfrm[i++];
	132	dst_prev->dev = rt->u.dst.dev;
	133	if (rt->u.dst.dev)
	134	dev_hold(rt->u.dst.dev);
	135	dst_prev->obsolete = -1;
	136	dst_prev->flags \|= DST_HOST;
	137	dst_prev->lastuse = jiffies;
	138	dst_prev->header_len = header_len;
1b5c2299	139	dst_prev->nfheader_len = 0;
1da177e4 LT	140	dst_prev->trailer_len = trailer_len;
	141	memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
	142
	143	/* Copy neighbout for reachability confirmation */
	144	dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour);
	145	dst_prev->input = rt->u.dst.input;
	146	dst_prev->output = xfrm4_output;
	147	if (rt->peer)
	148	atomic_inc(&rt->peer->refcnt);
	149	x->u.rt.peer = rt->peer;
	150	/* Sheit... I remember I did this right. Apparently,
	151	* it was magically lost, so this code needs audit */
	152	x->u.rt.rt_flags = rt0->rt_flags&(RTCF_BROADCAST\|RTCF_MULTICAST\|RTCF_LOCAL);
	153	x->u.rt.rt_type = rt->rt_type;
	154	x->u.rt.rt_src = rt0->rt_src;
	155	x->u.rt.rt_dst = rt0->rt_dst;
	156	x->u.rt.rt_gateway = rt->rt_gateway;
	157	x->u.rt.rt_spec_dst = rt0->rt_spec_dst;
aabc9761 HX	158	x->u.rt.idev = rt0->idev;
aabc9761 HX	159	in_dev_hold(rt0->idev);
1da177e4 LT	160	header_len -= x->u.dst.xfrm->props.header_len;
	161	trailer_len -= x->u.dst.xfrm->props.trailer_len;
	162	}
	163
	164	xfrm_init_pmtu(dst);
	165	return 0;
	166
	167	error:
	168	if (dst)
	169	dst_free(dst);
	170	return err;
	171	}
	172
	173	static void
	174	_decode_session4(struct sk_buff skb, struct flowi fl)
	175	{
	176	struct iphdr *iph = skb->nh.iph;
	177	u8 xprth = skb->nh.raw + iph->ihl4;
	178
	179	memset(fl, 0, sizeof(struct flowi));
	180	if (!(iph->frag_off & htons(IP_MF \| IP_OFFSET))) {
	181	switch (iph->protocol) {
	182	case IPPROTO_UDP:
	183	case IPPROTO_TCP:
	184	case IPPROTO_SCTP:
9e999993	185	case IPPROTO_DCCP:
1da177e4 LT	186	if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
	187	u16 ports = (u16 )xprth;
	188
	189	fl->fl_ip_sport = ports[0];
	190	fl->fl_ip_dport = ports[1];
	191	}
	192	break;
	193
	194	case IPPROTO_ICMP:
	195	if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
	196	u8 *icmp = xprth;
	197
	198	fl->fl_icmp_type = icmp[0];
	199	fl->fl_icmp_code = icmp[1];
	200	}
	201	break;
	202
	203	case IPPROTO_ESP:
	204	if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
	205	u32 ehdr = (u32 )xprth;
	206
	207	fl->fl_ipsec_spi = ehdr[0];
	208	}
	209	break;
	210
	211	case IPPROTO_AH:
	212	if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
	213	u32 ah_hdr = (u32)xprth;
	214
	215	fl->fl_ipsec_spi = ah_hdr[1];
	216	}
	217	break;
	218
	219	case IPPROTO_COMP:
	220	if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
	221	u16 ipcomp_hdr = (u16 )xprth;
	222
4195f814	223	fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
1da177e4 LT	224	}
	225	break;
	226	default:
	227	fl->fl_ipsec_spi = 0;
	228	break;
	229	};
	230	}
	231	fl->proto = iph->protocol;
	232	fl->fl4_dst = iph->daddr;
	233	fl->fl4_src = iph->saddr;
4da3089f	234	fl->fl4_tos = iph->tos;
1da177e4 LT	235	}
	236
	237	static inline int xfrm4_garbage_collect(void)
	238	{
1da177e4	239	xfrm4_policy_afinfo.garbage_collect();
1da177e4 LT	240	return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
	241	}
	242
	243	static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
	244	{
	245	struct xfrm_dst xdst = (struct xfrm_dst )dst;
	246	struct dst_entry *path = xdst->route;
	247
	248	path->ops->update_pmtu(path, mtu);
	249	}
	250
aabc9761 HX	251	static void xfrm4_dst_destroy(struct dst_entry *dst)
	252	{
	253	struct xfrm_dst xdst = (struct xfrm_dst )dst;
	254
	255	if (likely(xdst->u.rt.idev))
	256	in_dev_put(xdst->u.rt.idev);
	257	xfrm_dst_destroy(xdst);
	258	}
	259
	260	static void xfrm4_dst_ifdown(struct dst_entry dst, struct net_device dev,
	261	int unregister)
	262	{
	263	struct xfrm_dst *xdst;
	264
	265	if (!unregister)
	266	return;
	267
	268	xdst = (struct xfrm_dst *)dst;
	269	if (xdst->u.rt.idev->dev == dev) {
	270	struct in_device *loopback_idev = in_dev_get(&loopback_dev);
	271	BUG_ON(!loopback_idev);
	272
	273	do {
	274	in_dev_put(xdst->u.rt.idev);
	275	xdst->u.rt.idev = loopback_idev;
	276	in_dev_hold(loopback_idev);
	277	xdst = (struct xfrm_dst *)xdst->u.dst.child;
	278	} while (xdst->u.dst.xfrm);
	279
	280	__in_dev_put(loopback_idev);
	281	}
	282
	283	xfrm_dst_ifdown(dst, dev);
	284	}
	285
1da177e4 LT	286	static struct dst_ops xfrm4_dst_ops = {
	287	.family = AF_INET,
	288	.protocol = __constant_htons(ETH_P_IP),
	289	.gc = xfrm4_garbage_collect,
	290	.update_pmtu = xfrm4_update_pmtu,
aabc9761 HX	291	.destroy = xfrm4_dst_destroy,
aabc9761 HX	292	.ifdown = xfrm4_dst_ifdown,
1da177e4 LT	293	.gc_thresh = 1024,
	294	.entry_size = sizeof(struct xfrm_dst),
	295	};
	296
	297	static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
	298	.family = AF_INET,
1da177e4 LT	299	.dst_ops = &xfrm4_dst_ops,
	300	.dst_lookup = xfrm4_dst_lookup,
	301	.find_bundle = __xfrm4_find_bundle,
	302	.bundle_create = __xfrm4_bundle_create,
	303	.decode_session = _decode_session4,
	304	};
	305
	306	static void __init xfrm4_policy_init(void)
	307	{
	308	xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
	309	}
	310
	311	static void __exit xfrm4_policy_fini(void)
	312	{
	313	xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
	314	}
	315
	316	void __init xfrm4_init(void)
	317	{
	318	xfrm4_state_init();
	319	xfrm4_policy_init();
	320	}
	321