[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / xfrm4_policy.c

/*
 * xfrm4_policy.c
 *
 * Changes:
 *	Kazunori MIYAZAWA @USAGI
 * 	YOSHIFUJI Hideaki @USAGI
 *		Split up af-specific portion
 *
 */

#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/inetdevice.h>
#include <linux/if_tunnel.h>
#include <net/dst.h>
#include <net/xfrm.h>
#include <net/ip.h>

static struct xfrm_policy_afinfo xfrm4_policy_afinfo;

static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos,
					  const xfrm_address_t *saddr,
					  const xfrm_address_t *daddr)
{
	struct flowi4 fl4 = {
		.daddr = daddr->a4,
		.flowi4_tos = tos,
	};
	struct rtable *rt;

	if (saddr)
		fl4.saddr = saddr->a4;

	rt = __ip_route_output_key(net, &fl4);
	if (!IS_ERR(rt))
		return &rt->dst;

	return ERR_CAST(rt);
}

static int xfrm4_get_saddr(struct net *net,
			   xfrm_address_t *saddr, xfrm_address_t *daddr)
{
	struct dst_entry *dst;
	struct rtable *rt;

	dst = xfrm4_dst_lookup(net, 0, NULL, daddr);
	if (IS_ERR(dst))
		return -EHOSTUNREACH;

	rt = (struct rtable *)dst;
	saddr->a4 = rt->rt_src;
	dst_release(dst);
	return 0;
}

static int xfrm4_get_tos(const struct flowi *fl)
{
	return IPTOS_RT_MASK & fl->u.ip4.flowi4_tos; /* Strip ECN bits */
}

static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst,
			   int nfheader_len)
{
	return 0;
}

static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
			  const struct flowi *fl)
{
	struct rtable *rt = (struct rtable *)xdst->route;
	const struct flowi4 *fl4 = &fl->u.ip4;

	rt->rt_key_dst = fl4->daddr;
	rt->rt_key_src = fl4->saddr;
	rt->rt_tos = fl4->flowi4_tos;
	rt->rt_route_iif = fl4->flowi4_iif;
	rt->rt_iif = fl4->flowi4_iif;
	rt->rt_oif = fl4->flowi4_oif;
	rt->rt_mark = fl4->flowi4_mark;

	xdst->u.dst.dev = dev;
	dev_hold(dev);

	xdst->u.rt.peer = rt->peer;
	if (rt->peer)
		atomic_inc(&rt->peer->refcnt);

	/* Sheit... I remember I did this right. Apparently,
	 * it was magically lost, so this code needs audit */
	xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
					      RTCF_LOCAL);
	xdst->u.rt.rt_type = rt->rt_type;
	xdst->u.rt.rt_src = rt->rt_src;
	xdst->u.rt.rt_dst = rt->rt_dst;
	xdst->u.rt.rt_gateway = rt->rt_gateway;
	xdst->u.rt.rt_spec_dst = rt->rt_spec_dst;

	return 0;
}

static void
_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
{
	struct iphdr *iph = ip_hdr(skb);
	u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
	struct flowi4 *fl4 = &fl->u.ip4;

	memset(fl4, 0, sizeof(struct flowi4));
	fl4->flowi4_mark = skb->mark;

	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 (xprth + 4 < skb->data ||
			    pskb_may_pull(skb, xprth + 4 - skb->data)) {
				__be16 *ports = (__be16 *)xprth;

				fl4->fl4_sport = ports[!!reverse];
				fl4->fl4_dport = ports[!reverse];
			}
			break;

		case IPPROTO_ICMP:
			if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
				u8 *icmp = xprth;

				fl4->fl4_icmp_type = icmp[0];
				fl4->fl4_icmp_code = icmp[1];
			}
			break;

		case IPPROTO_ESP:
			if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
				__be32 *ehdr = (__be32 *)xprth;

				fl4->fl4_ipsec_spi = ehdr[0];
			}
			break;

		case IPPROTO_AH:
			if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
				__be32 *ah_hdr = (__be32*)xprth;

				fl4->fl4_ipsec_spi = ah_hdr[1];
			}
			break;

		case IPPROTO_COMP:
			if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
				__be16 *ipcomp_hdr = (__be16 *)xprth;

				fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
			}
			break;

		case IPPROTO_GRE:
			if (pskb_may_pull(skb, xprth + 12 - skb->data)) {
				__be16 *greflags = (__be16 *)xprth;
				__be32 *gre_hdr = (__be32 *)xprth;

				if (greflags[0] & GRE_KEY) {
					if (greflags[0] & GRE_CSUM)
						gre_hdr++;
					fl4->fl4_gre_key = gre_hdr[1];
				}
			}
			break;

		default:
			fl4->fl4_ipsec_spi = 0;
			break;
		}
	}
	fl4->flowi4_proto = iph->protocol;
	fl4->daddr = reverse ? iph->saddr : iph->daddr;
	fl4->saddr = reverse ? iph->daddr : iph->saddr;
	fl4->flowi4_tos = iph->tos;
}

static inline int xfrm4_garbage_collect(struct dst_ops *ops)
{
	struct net *net = container_of(ops, struct net, xfrm.xfrm4_dst_ops);

	xfrm4_policy_afinfo.garbage_collect(net);
	return (dst_entries_get_slow(ops) > 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;

	dst_destroy_metrics_generic(dst);

	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)
{
	if (!unregister)
		return;

	xfrm_dst_ifdown(dst, dev);
}

static struct dst_ops xfrm4_dst_ops = {
	.family =		AF_INET,
	.protocol =		cpu_to_be16(ETH_P_IP),
	.gc =			xfrm4_garbage_collect,
	.update_pmtu =		xfrm4_update_pmtu,
	.cow_metrics =		dst_cow_metrics_generic,
	.destroy =		xfrm4_dst_destroy,
	.ifdown =		xfrm4_dst_ifdown,
	.local_out =		__ip_local_out,
	.gc_thresh =		1024,
};

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,
	.decode_session =	_decode_session4,
	.get_tos =		xfrm4_get_tos,
	.init_path =		xfrm4_init_path,
	.fill_dst =		xfrm4_fill_dst,
	.blackhole_route =	ipv4_blackhole_route,
};

#ifdef CONFIG_SYSCTL
static struct ctl_table xfrm4_policy_table[] = {
	{
		.procname       = "xfrm4_gc_thresh",
		.data           = &init_net.xfrm.xfrm4_dst_ops.gc_thresh,
		.maxlen         = sizeof(int),
		.mode           = 0644,
		.proc_handler   = proc_dointvec,
	},
	{ }
};

static struct ctl_table_header *sysctl_hdr;
#endif

static void __init xfrm4_policy_init(void)
{
	xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
}

static void __exit xfrm4_policy_fini(void)
{
#ifdef CONFIG_SYSCTL
	if (sysctl_hdr)
		unregister_net_sysctl_table(sysctl_hdr);
#endif
	xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
}

void __init xfrm4_init(int rt_max_size)
{
	/*
	 * Select a default value for the gc_thresh based on the main route
	 * table hash size.  It seems to me the worst case scenario is when
	 * we have ipsec operating in transport mode, in which we create a
	 * dst_entry per socket.  The xfrm gc algorithm starts trying to remove
	 * entries at gc_thresh, and prevents new allocations as 2*gc_thresh
	 * so lets set an initial xfrm gc_thresh value at the rt_max_size/2.
	 * That will let us store an ipsec connection per route table entry,
	 * and start cleaning when were 1/2 full
	 */
	xfrm4_dst_ops.gc_thresh = rt_max_size/2;
	dst_entries_init(&xfrm4_dst_ops);

	xfrm4_state_init();
	xfrm4_policy_init();
#ifdef CONFIG_SYSCTL
	sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv4_ctl_path,
						xfrm4_policy_table);
#endif
}
Commit	Line	Data
	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
	11	#include <linux/err.h>
	12	#include <linux/kernel.h>
	13	#include <linux/inetdevice.h>
	14	#include <linux/if_tunnel.h>
	15	#include <net/dst.h>
	16	#include <net/xfrm.h>
	17	#include <net/ip.h>
	18
	19	static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
	20
	21	static struct dst_entry xfrm4_dst_lookup(struct net net, int tos,
	22	const xfrm_address_t *saddr,
	23	const xfrm_address_t *daddr)
	24	{
	25	struct flowi4 fl4 = {
	26	.daddr = daddr->a4,
	27	.flowi4_tos = tos,
	28	};
	29	struct rtable *rt;
	30
	31	if (saddr)
	32	fl4.saddr = saddr->a4;
	33
	34	rt = __ip_route_output_key(net, &fl4);
	35	if (!IS_ERR(rt))
	36	return &rt->dst;
	37
	38	return ERR_CAST(rt);
	39	}
	40
	41	static int xfrm4_get_saddr(struct net *net,
	42	xfrm_address_t saddr, xfrm_address_t daddr)
	43	{
	44	struct dst_entry *dst;
	45	struct rtable *rt;
	46
	47	dst = xfrm4_dst_lookup(net, 0, NULL, daddr);
	48	if (IS_ERR(dst))
	49	return -EHOSTUNREACH;
	50
	51	rt = (struct rtable *)dst;
	52	saddr->a4 = rt->rt_src;
	53	dst_release(dst);
	54	return 0;
	55	}
	56
	57	static int xfrm4_get_tos(const struct flowi *fl)
	58	{
	59	return IPTOS_RT_MASK & fl->u.ip4.flowi4_tos; /* Strip ECN bits */
	60	}
	61
	62	static int xfrm4_init_path(struct xfrm_dst path, struct dst_entry dst,
	63	int nfheader_len)
	64	{
	65	return 0;
	66	}
	67
	68	static int xfrm4_fill_dst(struct xfrm_dst xdst, struct net_device dev,
	69	const struct flowi *fl)
	70	{
	71	struct rtable rt = (struct rtable )xdst->route;
	72	const struct flowi4 *fl4 = &fl->u.ip4;
	73
	74	rt->rt_key_dst = fl4->daddr;
	75	rt->rt_key_src = fl4->saddr;
	76	rt->rt_tos = fl4->flowi4_tos;
	77	rt->rt_route_iif = fl4->flowi4_iif;
	78	rt->rt_iif = fl4->flowi4_iif;
	79	rt->rt_oif = fl4->flowi4_oif;
	80	rt->rt_mark = fl4->flowi4_mark;
	81
	82	xdst->u.dst.dev = dev;
	83	dev_hold(dev);
	84
	85	xdst->u.rt.peer = rt->peer;
	86	if (rt->peer)
	87	atomic_inc(&rt->peer->refcnt);
	88
	89	/* Sheit... I remember I did this right. Apparently,
	90	* it was magically lost, so this code needs audit */
	91	xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST \| RTCF_MULTICAST \|
	92	RTCF_LOCAL);
	93	xdst->u.rt.rt_type = rt->rt_type;
	94	xdst->u.rt.rt_src = rt->rt_src;
	95	xdst->u.rt.rt_dst = rt->rt_dst;
	96	xdst->u.rt.rt_gateway = rt->rt_gateway;
	97	xdst->u.rt.rt_spec_dst = rt->rt_spec_dst;
	98
	99	return 0;
	100	}
	101
	102	static void
	103	_decode_session4(struct sk_buff skb, struct flowi fl, int reverse)
	104	{
	105	struct iphdr *iph = ip_hdr(skb);
	106	u8 xprth = skb_network_header(skb) + iph->ihl 4;
	107	struct flowi4 *fl4 = &fl->u.ip4;
	108
	109	memset(fl4, 0, sizeof(struct flowi4));
	110	fl4->flowi4_mark = skb->mark;
	111
	112	if (!(iph->frag_off & htons(IP_MF \| IP_OFFSET))) {
	113	switch (iph->protocol) {
	114	case IPPROTO_UDP:
	115	case IPPROTO_UDPLITE:
	116	case IPPROTO_TCP:
	117	case IPPROTO_SCTP:
	118	case IPPROTO_DCCP:
	119	if (xprth + 4 < skb->data \|\|
	120	pskb_may_pull(skb, xprth + 4 - skb->data)) {
	121	__be16 ports = (__be16 )xprth;
	122
	123	fl4->fl4_sport = ports[!!reverse];
	124	fl4->fl4_dport = ports[!reverse];
	125	}
	126	break;
	127
	128	case IPPROTO_ICMP:
	129	if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
	130	u8 *icmp = xprth;
	131
	132	fl4->fl4_icmp_type = icmp[0];
	133	fl4->fl4_icmp_code = icmp[1];
	134	}
	135	break;
	136
	137	case IPPROTO_ESP:
	138	if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
	139	__be32 ehdr = (__be32 )xprth;
	140
	141	fl4->fl4_ipsec_spi = ehdr[0];
	142	}
	143	break;
	144
	145	case IPPROTO_AH:
	146	if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
	147	__be32 ah_hdr = (__be32)xprth;
	148
	149	fl4->fl4_ipsec_spi = ah_hdr[1];
	150	}
	151	break;
	152
	153	case IPPROTO_COMP:
	154	if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
	155	__be16 ipcomp_hdr = (__be16 )xprth;
	156
	157	fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
	158	}
	159	break;
	160
	161	case IPPROTO_GRE:
	162	if (pskb_may_pull(skb, xprth + 12 - skb->data)) {
	163	__be16 greflags = (__be16 )xprth;
	164	__be32 gre_hdr = (__be32 )xprth;
	165
	166	if (greflags[0] & GRE_KEY) {
	167	if (greflags[0] & GRE_CSUM)
	168	gre_hdr++;
	169	fl4->fl4_gre_key = gre_hdr[1];
	170	}
	171	}
	172	break;
	173
	174	default:
	175	fl4->fl4_ipsec_spi = 0;
	176	break;
	177	}
	178	}
	179	fl4->flowi4_proto = iph->protocol;
	180	fl4->daddr = reverse ? iph->saddr : iph->daddr;
	181	fl4->saddr = reverse ? iph->daddr : iph->saddr;
	182	fl4->flowi4_tos = iph->tos;
	183	}
	184
	185	static inline int xfrm4_garbage_collect(struct dst_ops *ops)
	186	{
	187	struct net *net = container_of(ops, struct net, xfrm.xfrm4_dst_ops);
	188
	189	xfrm4_policy_afinfo.garbage_collect(net);
	190	return (dst_entries_get_slow(ops) > ops->gc_thresh * 2);
	191	}
	192
	193	static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
	194	{
	195	struct xfrm_dst xdst = (struct xfrm_dst )dst;
	196	struct dst_entry *path = xdst->route;
	197
	198	path->ops->update_pmtu(path, mtu);
	199	}
	200
	201	static void xfrm4_dst_destroy(struct dst_entry *dst)
	202	{
	203	struct xfrm_dst xdst = (struct xfrm_dst )dst;
	204
	205	dst_destroy_metrics_generic(dst);
	206
	207	if (likely(xdst->u.rt.peer))
	208	inet_putpeer(xdst->u.rt.peer);
	209
	210	xfrm_dst_destroy(xdst);
	211	}
	212
	213	static void xfrm4_dst_ifdown(struct dst_entry dst, struct net_device dev,
	214	int unregister)
	215	{
	216	if (!unregister)
	217	return;
	218
	219	xfrm_dst_ifdown(dst, dev);
	220	}
	221
	222	static struct dst_ops xfrm4_dst_ops = {
	223	.family = AF_INET,
	224	.protocol = cpu_to_be16(ETH_P_IP),
	225	.gc = xfrm4_garbage_collect,
	226	.update_pmtu = xfrm4_update_pmtu,
	227	.cow_metrics = dst_cow_metrics_generic,
	228	.destroy = xfrm4_dst_destroy,
	229	.ifdown = xfrm4_dst_ifdown,
	230	.local_out = __ip_local_out,
	231	.gc_thresh = 1024,
	232	};
	233
	234	static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
	235	.family = AF_INET,
	236	.dst_ops = &xfrm4_dst_ops,
	237	.dst_lookup = xfrm4_dst_lookup,
	238	.get_saddr = xfrm4_get_saddr,
	239	.decode_session = _decode_session4,
	240	.get_tos = xfrm4_get_tos,
	241	.init_path = xfrm4_init_path,
	242	.fill_dst = xfrm4_fill_dst,
	243	.blackhole_route = ipv4_blackhole_route,
	244	};
	245
	246	#ifdef CONFIG_SYSCTL
	247	static struct ctl_table xfrm4_policy_table[] = {
	248	{
	249	.procname = "xfrm4_gc_thresh",
	250	.data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh,
	251	.maxlen = sizeof(int),
	252	.mode = 0644,
	253	.proc_handler = proc_dointvec,
	254	},
	255	{ }
	256	};
	257
	258	static struct ctl_table_header *sysctl_hdr;
	259	#endif
	260
	261	static void __init xfrm4_policy_init(void)
	262	{
	263	xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
	264	}
	265
	266	static void __exit xfrm4_policy_fini(void)
	267	{
	268	#ifdef CONFIG_SYSCTL
	269	if (sysctl_hdr)
	270	unregister_net_sysctl_table(sysctl_hdr);
	271	#endif
	272	xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
	273	}
	274
	275	void __init xfrm4_init(int rt_max_size)
	276	{
	277	/*
	278	* Select a default value for the gc_thresh based on the main route
	279	* table hash size. It seems to me the worst case scenario is when
	280	* we have ipsec operating in transport mode, in which we create a
	281	* dst_entry per socket. The xfrm gc algorithm starts trying to remove
	282	* entries at gc_thresh, and prevents new allocations as 2*gc_thresh
	283	* so lets set an initial xfrm gc_thresh value at the rt_max_size/2.
	284	* That will let us store an ipsec connection per route table entry,
	285	* and start cleaning when were 1/2 full
	286	*/
	287	xfrm4_dst_ops.gc_thresh = rt_max_size/2;
	288	dst_entries_init(&xfrm4_dst_ops);
	289
	290	xfrm4_state_init();
	291	xfrm4_policy_init();
	292	#ifdef CONFIG_SYSCTL
	293	sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv4_ctl_path,
	294	xfrm4_policy_table);
	295	#endif
	296	}
	297