[net-next-2.6.git] / net / ipv4 / fib_rules.c

/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		IPv4 Forwarding Information Base: policy rules.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 * 		Thomas Graf <tgraf@suug.ch>
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 * Fixes:
 * 		Rani Assaf	:	local_rule cannot be deleted
 *		Marc Boucher	:	routing by fwmark
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/netlink.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/rcupdate.h>
#include <net/ip.h>
#include <net/route.h>
#include <net/tcp.h>
#include <net/ip_fib.h>
#include <net/fib_rules.h>

static struct fib_rules_ops fib4_rules_ops;

struct fib4_rule
{
	struct fib_rule		common;
	u8			dst_len;
	u8			src_len;
	u8			tos;
	u32			src;
	u32			srcmask;
	u32			dst;
	u32			dstmask;
#ifdef CONFIG_IP_ROUTE_FWMARK
	u32			fwmark;
#endif
#ifdef CONFIG_NET_CLS_ROUTE
	u32			tclassid;
#endif
};

static struct fib4_rule default_rule = {
	.common = {
		.refcnt =	ATOMIC_INIT(2),
		.pref =		0x7FFF,
		.table =	RT_TABLE_DEFAULT,
		.action =	FR_ACT_TO_TBL,
	},
};

static struct fib4_rule main_rule = {
	.common = {
		.refcnt =	ATOMIC_INIT(2),
		.pref =		0x7FFE,
		.table =	RT_TABLE_MAIN,
		.action =	FR_ACT_TO_TBL,
	},
};

static struct fib4_rule local_rule = {
	.common = {
		.refcnt =	ATOMIC_INIT(2),
		.table =	RT_TABLE_LOCAL,
		.action =	FR_ACT_TO_TBL,
		.flags =	FIB_RULE_PERMANENT,
	},
};

static LIST_HEAD(fib4_rules);

#ifdef CONFIG_NET_CLS_ROUTE
u32 fib_rules_tclass(struct fib_result *res)
{
	return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
}
#endif

int fib_lookup(struct flowi *flp, struct fib_result *res)
{
	struct fib_lookup_arg arg = {
		.result = res,
	};
	int err;

	err = fib_rules_lookup(&fib4_rules_ops, flp, 0, &arg);
	res->r = arg.rule;

	return err;
}

int fib4_rule_action(struct fib_rule *rule, struct flowi *flp, int flags,
		     struct fib_lookup_arg *arg)
{
	int err = -EAGAIN;
	struct fib_table *tbl;

	switch (rule->action) {
	case FR_ACT_TO_TBL:
		break;

	case FR_ACT_UNREACHABLE:
		err = -ENETUNREACH;
		goto errout;

	case FR_ACT_PROHIBIT:
		err = -EACCES;
		goto errout;

	case FR_ACT_BLACKHOLE:
	default:
		err = -EINVAL;
		goto errout;
	}

	if ((tbl = fib_get_table(rule->table)) == NULL)
		goto errout;

	err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result);
	if (err > 0)
		err = -EAGAIN;
errout:
	return err;
}


void fib_select_default(const struct flowi *flp, struct fib_result *res)
{
	if (res->r && res->r->action == FR_ACT_TO_TBL &&
	    FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) {
		struct fib_table *tb;
		if ((tb = fib_get_table(res->r->table)) != NULL)
			tb->tb_select_default(tb, flp, res);
	}
}

static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
{
	struct fib4_rule *r = (struct fib4_rule *) rule;
	u32 daddr = fl->fl4_dst;
	u32 saddr = fl->fl4_src;

	if (((saddr ^ r->src) & r->srcmask) ||
	    ((daddr ^ r->dst) & r->dstmask))
		return 0;

	if (r->tos && (r->tos != fl->fl4_tos))
		return 0;

#ifdef CONFIG_IP_ROUTE_FWMARK
	if (r->fwmark && (r->fwmark != fl->fl4_fwmark))
		return 0;
#endif

	return 1;
}

static struct fib_table *fib_empty_table(void)
{
	int id;

	for (id = 1; id <= RT_TABLE_MAX; id++)
		if (fib_tables[id] == NULL)
			return __fib_new_table(id);
	return NULL;
}

static struct nla_policy fib4_rule_policy[FRA_MAX+1] __read_mostly = {
	[FRA_IFNAME]	= { .type = NLA_STRING },
	[FRA_PRIORITY]	= { .type = NLA_U32 },
	[FRA_SRC]	= { .type = NLA_U32 },
	[FRA_DST]	= { .type = NLA_U32 },
	[FRA_FWMARK]	= { .type = NLA_U32 },
	[FRA_FLOW]	= { .type = NLA_U32 },
};

static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
			       struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
			       struct nlattr **tb)
{
	int err = -EINVAL;
	struct fib4_rule *rule4 = (struct fib4_rule *) rule;

	if (frh->src_len > 32 || frh->dst_len > 32 ||
	    (frh->tos & ~IPTOS_TOS_MASK))
		goto errout;

	if (rule->table == RT_TABLE_UNSPEC) {
		if (rule->action == FR_ACT_TO_TBL) {
			struct fib_table *table;

			table = fib_empty_table();
			if (table == NULL) {
				err = -ENOBUFS;
				goto errout;
			}

			rule->table = table->tb_id;
		}
	}

	if (tb[FRA_SRC])
		rule4->src = nla_get_u32(tb[FRA_SRC]);

	if (tb[FRA_DST])
		rule4->dst = nla_get_u32(tb[FRA_DST]);

#ifdef CONFIG_IP_ROUTE_FWMARK
	if (tb[FRA_FWMARK])
		rule4->fwmark = nla_get_u32(tb[FRA_FWMARK]);
#endif

#ifdef CONFIG_NET_CLS_ROUTE
	if (tb[FRA_FLOW])
		rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
#endif

	rule4->src_len = frh->src_len;
	rule4->srcmask = inet_make_mask(rule4->src_len);
	rule4->dst_len = frh->dst_len;
	rule4->dstmask = inet_make_mask(rule4->dst_len);
	rule4->tos = frh->tos;

	err = 0;
errout:
	return err;
}

static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
			     struct nlattr **tb)
{
	struct fib4_rule *rule4 = (struct fib4_rule *) rule;

	if (frh->src_len && (rule4->src_len != frh->src_len))
		return 0;

	if (frh->dst_len && (rule4->dst_len != frh->dst_len))
		return 0;

	if (frh->tos && (rule4->tos != frh->tos))
		return 0;

#ifdef CONFIG_IP_ROUTE_FWMARK
	if (tb[FRA_FWMARK] && (rule4->fwmark != nla_get_u32(tb[FRA_FWMARK])))
		return 0;
#endif

#ifdef CONFIG_NET_CLS_ROUTE
	if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
		return 0;
#endif

	if (tb[FRA_SRC] && (rule4->src != nla_get_u32(tb[FRA_SRC])))
		return 0;

	if (tb[FRA_DST] && (rule4->dst != nla_get_u32(tb[FRA_DST])))
		return 0;

	return 1;
}

static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
			  struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
{
	struct fib4_rule *rule4 = (struct fib4_rule *) rule;

	frh->family = AF_INET;
	frh->dst_len = rule4->dst_len;
	frh->src_len = rule4->src_len;
	frh->tos = rule4->tos;

#ifdef CONFIG_IP_ROUTE_FWMARK
	if (rule4->fwmark)
		NLA_PUT_U32(skb, FRA_FWMARK, rule4->fwmark);
#endif

	if (rule4->dst_len)
		NLA_PUT_U32(skb, FRA_DST, rule4->dst);

	if (rule4->src_len)
		NLA_PUT_U32(skb, FRA_SRC, rule4->src);

#ifdef CONFIG_NET_CLS_ROUTE
	if (rule4->tclassid)
		NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid);
#endif
	return 0;

nla_put_failure:
	return -ENOBUFS;
}

int fib4_rules_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
	return fib_rules_dump(skb, cb, AF_INET);
}

static u32 fib4_rule_default_pref(void)
{
	struct list_head *pos;
	struct fib_rule *rule;

	if (!list_empty(&fib4_rules)) {
		pos = fib4_rules.next;
		if (pos->next != &fib4_rules) {
			rule = list_entry(pos->next, struct fib_rule, list);
			if (rule->pref)
				return rule->pref - 1;
		}
	}

	return 0;
}

static struct fib_rules_ops fib4_rules_ops = {
	.family		= AF_INET,
	.rule_size	= sizeof(struct fib4_rule),
	.action		= fib4_rule_action,
	.match		= fib4_rule_match,
	.configure	= fib4_rule_configure,
	.compare	= fib4_rule_compare,
	.fill		= fib4_rule_fill,
	.default_pref	= fib4_rule_default_pref,
	.nlgroup	= RTNLGRP_IPV4_RULE,
	.policy		= fib4_rule_policy,
	.rules_list	= &fib4_rules,
	.owner		= THIS_MODULE,
};

void __init fib4_rules_init(void)
{
	list_add_tail(&local_rule.common.list, &fib4_rules);
	list_add_tail(&main_rule.common.list, &fib4_rules);
	list_add_tail(&default_rule.common.list, &fib4_rules);

	fib_rules_register(&fib4_rules_ops);
}

void __exit fib4_rules_cleanup(void)
{
	fib_rules_unregister(&fib4_rules_ops);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* INET An implementation of the TCP/IP protocol suite for the LINUX
	3	* operating system. INET is implemented using the BSD Socket
	4	* interface as the means of communication with the user level.
	5	*
	6	* IPv4 Forwarding Information Base: policy rules.
	7	*
1da177e4	8	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
e1ef4bf2	9	* Thomas Graf <tgraf@suug.ch>
1da177e4 LT	10	*
	11	* This program is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU General Public License
	13	* as published by the Free Software Foundation; either version
	14	* 2 of the License, or (at your option) any later version.
	15	*
	16	* Fixes:
	17	* Rani Assaf : local_rule cannot be deleted
	18	* Marc Boucher : routing by fwmark
	19	*/
	20
1da177e4 LT	21	#include <linux/types.h>
1da177e4 LT	22	#include <linux/kernel.h>
1da177e4	23	#include <linux/netdevice.h>
1da177e4	24	#include <linux/netlink.h>
e1ef4bf2	25	#include <linux/inetdevice.h>
1da177e4	26	#include <linux/init.h>
7b204afd RO	27	#include <linux/list.h>
7b204afd RO	28	#include <linux/rcupdate.h>
1da177e4	29	#include <net/ip.h>
1da177e4 LT	30	#include <net/route.h>
1da177e4 LT	31	#include <net/tcp.h>
1da177e4	32	#include <net/ip_fib.h>
e1ef4bf2	33	#include <net/fib_rules.h>
1da177e4	34
e1ef4bf2	35	static struct fib_rules_ops fib4_rules_ops;
1da177e4	36
e1ef4bf2	37	struct fib4_rule
1da177e4	38	{
e1ef4bf2 TG	39	struct fib_rule common;
	40	u8 dst_len;
	41	u8 src_len;
	42	u8 tos;
	43	u32 src;
	44	u32 srcmask;
	45	u32 dst;
	46	u32 dstmask;
1da177e4	47	#ifdef CONFIG_IP_ROUTE_FWMARK
e1ef4bf2	48	u32 fwmark;
1da177e4	49	#endif
1da177e4	50	#ifdef CONFIG_NET_CLS_ROUTE
e1ef4bf2	51	u32 tclassid;
1da177e4	52	#endif
1da177e4 LT	53	};
1da177e4 LT	54
e1ef4bf2 TG	55	static struct fib4_rule default_rule = {
	56	.common = {
	57	.refcnt = ATOMIC_INIT(2),
	58	.pref = 0x7FFF,
	59	.table = RT_TABLE_DEFAULT,
	60	.action = FR_ACT_TO_TBL,
	61	},
1da177e4 LT	62	};
1da177e4 LT	63
e1ef4bf2 TG	64	static struct fib4_rule main_rule = {
	65	.common = {
	66	.refcnt = ATOMIC_INIT(2),
	67	.pref = 0x7FFE,
	68	.table = RT_TABLE_MAIN,
	69	.action = FR_ACT_TO_TBL,
	70	},
1da177e4 LT	71	};
1da177e4 LT	72
e1ef4bf2 TG	73	static struct fib4_rule local_rule = {
	74	.common = {
	75	.refcnt = ATOMIC_INIT(2),
	76	.table = RT_TABLE_LOCAL,
	77	.action = FR_ACT_TO_TBL,
	78	.flags = FIB_RULE_PERMANENT,
	79	},
1da177e4 LT	80	};
1da177e4 LT	81
e1ef4bf2 TG	82	static LIST_HEAD(fib4_rules);
	83
	84	#ifdef CONFIG_NET_CLS_ROUTE
	85	u32 fib_rules_tclass(struct fib_result *res)
	86	{
	87	return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
	88	}
	89	#endif
7b204afd	90
e1ef4bf2 TG	91	int fib_lookup(struct flowi flp, struct fib_result res)
	92	{
	93	struct fib_lookup_arg arg = {
	94	.result = res,
	95	};
	96	int err;
1da177e4	97
e1ef4bf2 TG	98	err = fib_rules_lookup(&fib4_rules_ops, flp, 0, &arg);
e1ef4bf2 TG	99	res->r = arg.rule;
a5cdc030	100
e1ef4bf2 TG	101	return err;
	102	}
	103
	104	int fib4_rule_action(struct fib_rule rule, struct flowi flp, int flags,
	105	struct fib_lookup_arg *arg)
1da177e4	106	{
e1ef4bf2 TG	107	int err = -EAGAIN;
	108	struct fib_table *tbl;
	109
	110	switch (rule->action) {
	111	case FR_ACT_TO_TBL:
	112	break;
	113
	114	case FR_ACT_UNREACHABLE:
	115	err = -ENETUNREACH;
	116	goto errout;
	117
	118	case FR_ACT_PROHIBIT:
	119	err = -EACCES;
	120	goto errout;
	121
	122	case FR_ACT_BLACKHOLE:
	123	default:
	124	err = -EINVAL;
	125	goto errout;
1da177e4	126	}
e1ef4bf2 TG	127
	128	if ((tbl = fib_get_table(rule->table)) == NULL)
	129	goto errout;
	130
	131	err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result);
	132	if (err > 0)
	133	err = -EAGAIN;
	134	errout:
1da177e4 LT	135	return err;
	136	}
	137
e1ef4bf2 TG	138
	139	void fib_select_default(const struct flowi flp, struct fib_result res)
	140	{
	141	if (res->r && res->r->action == FR_ACT_TO_TBL &&
	142	FIB_RES_GW(res) && FIB_RES_NH(res).nh_scope == RT_SCOPE_LINK) {
	143	struct fib_table *tb;
	144	if ((tb = fib_get_table(res->r->table)) != NULL)
	145	tb->tb_select_default(tb, flp, res);
	146	}
	147	}
	148
	149	static int fib4_rule_match(struct fib_rule rule, struct flowi fl, int flags)
	150	{
	151	struct fib4_rule r = (struct fib4_rule ) rule;
	152	u32 daddr = fl->fl4_dst;
	153	u32 saddr = fl->fl4_src;
	154
	155	if (((saddr ^ r->src) & r->srcmask) \|\|
	156	((daddr ^ r->dst) & r->dstmask))
	157	return 0;
	158
	159	if (r->tos && (r->tos != fl->fl4_tos))
	160	return 0;
	161
	162	#ifdef CONFIG_IP_ROUTE_FWMARK
	163	if (r->fwmark && (r->fwmark != fl->fl4_fwmark))
	164	return 0;
	165	#endif
	166
	167	return 1;
	168	}
1da177e4 LT	169
	170	static struct fib_table *fib_empty_table(void)
	171	{
	172	int id;
	173
	174	for (id = 1; id <= RT_TABLE_MAX; id++)
	175	if (fib_tables[id] == NULL)
	176	return __fib_new_table(id);
	177	return NULL;
	178	}
	179
e1ef4bf2 TG	180	static struct nla_policy fib4_rule_policy[FRA_MAX+1] __read_mostly = {
	181	[FRA_IFNAME] = { .type = NLA_STRING },
	182	[FRA_PRIORITY] = { .type = NLA_U32 },
	183	[FRA_SRC] = { .type = NLA_U32 },
	184	[FRA_DST] = { .type = NLA_U32 },
	185	[FRA_FWMARK] = { .type = NLA_U32 },
	186	[FRA_FLOW] = { .type = NLA_U32 },
	187	};
7b204afd	188
e1ef4bf2 TG	189	static int fib4_rule_configure(struct fib_rule rule, struct sk_buff skb,
	190	struct nlmsghdr nlh, struct fib_rule_hdr frh,
	191	struct nlattr **tb)
1da177e4	192	{
e1ef4bf2 TG	193	int err = -EINVAL;
e1ef4bf2 TG	194	struct fib4_rule rule4 = (struct fib4_rule ) rule;
1da177e4	195
e1ef4bf2 TG	196	if (frh->src_len > 32 \|\| frh->dst_len > 32 \|\|
	197	(frh->tos & ~IPTOS_TOS_MASK))
	198	goto errout;
7b204afd	199
e1ef4bf2 TG	200	if (rule->table == RT_TABLE_UNSPEC) {
	201	if (rule->action == FR_ACT_TO_TBL) {
	202	struct fib_table *table;
1da177e4	203
e1ef4bf2 TG	204	table = fib_empty_table();
	205	if (table == NULL) {
	206	err = -ENOBUFS;
	207	goto errout;
	208	}
1da177e4	209
e1ef4bf2	210	rule->table = table->tb_id;
1da177e4 LT	211	}
	212	}
	213
e1ef4bf2 TG	214	if (tb[FRA_SRC])
e1ef4bf2 TG	215	rule4->src = nla_get_u32(tb[FRA_SRC]);
7b204afd	216
e1ef4bf2 TG	217	if (tb[FRA_DST])
e1ef4bf2 TG	218	rule4->dst = nla_get_u32(tb[FRA_DST]);
7b204afd	219
e1ef4bf2 TG	220	#ifdef CONFIG_IP_ROUTE_FWMARK
	221	if (tb[FRA_FWMARK])
	222	rule4->fwmark = nla_get_u32(tb[FRA_FWMARK]);
	223	#endif
1da177e4 LT	224
1da177e4 LT	225	#ifdef CONFIG_NET_CLS_ROUTE
e1ef4bf2 TG	226	if (tb[FRA_FLOW])
e1ef4bf2 TG	227	rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
1da177e4 LT	228	#endif
1da177e4 LT	229
e1ef4bf2 TG	230	rule4->src_len = frh->src_len;
	231	rule4->srcmask = inet_make_mask(rule4->src_len);
	232	rule4->dst_len = frh->dst_len;
	233	rule4->dstmask = inet_make_mask(rule4->dst_len);
	234	rule4->tos = frh->tos;
7b204afd	235
e1ef4bf2 TG	236	err = 0;
	237	errout:
	238	return err;
1da177e4 LT	239	}
1da177e4 LT	240
e1ef4bf2 TG	241	static int fib4_rule_compare(struct fib_rule rule, struct fib_rule_hdr frh,
e1ef4bf2 TG	242	struct nlattr **tb)
1da177e4	243	{
e1ef4bf2	244	struct fib4_rule rule4 = (struct fib4_rule ) rule;
1da177e4	245
e1ef4bf2 TG	246	if (frh->src_len && (rule4->src_len != frh->src_len))
e1ef4bf2 TG	247	return 0;
1da177e4	248
e1ef4bf2 TG	249	if (frh->dst_len && (rule4->dst_len != frh->dst_len))
e1ef4bf2 TG	250	return 0;
7b204afd	251
e1ef4bf2 TG	252	if (frh->tos && (rule4->tos != frh->tos))
e1ef4bf2 TG	253	return 0;
7b204afd	254
1da177e4	255	#ifdef CONFIG_IP_ROUTE_FWMARK
e1ef4bf2 TG	256	if (tb[FRA_FWMARK] && (rule4->fwmark != nla_get_u32(tb[FRA_FWMARK])))
e1ef4bf2 TG	257	return 0;
1da177e4	258	#endif
1da177e4	259
e1ef4bf2 TG	260	#ifdef CONFIG_NET_CLS_ROUTE
	261	if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
	262	return 0;
	263	#endif
1da177e4	264
e1ef4bf2 TG	265	if (tb[FRA_SRC] && (rule4->src != nla_get_u32(tb[FRA_SRC])))
e1ef4bf2 TG	266	return 0;
1da177e4	267
e1ef4bf2 TG	268	if (tb[FRA_DST] && (rule4->dst != nla_get_u32(tb[FRA_DST])))
e1ef4bf2 TG	269	return 0;
1da177e4	270
e1ef4bf2	271	return 1;
1da177e4 LT	272	}
1da177e4 LT	273
e1ef4bf2 TG	274	static int fib4_rule_fill(struct fib_rule rule, struct sk_buff skb,
	275	struct nlmsghdr nlh, struct fib_rule_hdr frh)
	276	{
	277	struct fib4_rule rule4 = (struct fib4_rule ) rule;
1da177e4	278
e1ef4bf2 TG	279	frh->family = AF_INET;
	280	frh->dst_len = rule4->dst_len;
	281	frh->src_len = rule4->src_len;
	282	frh->tos = rule4->tos;
1da177e4	283
1da177e4	284	#ifdef CONFIG_IP_ROUTE_FWMARK
e1ef4bf2 TG	285	if (rule4->fwmark)
e1ef4bf2 TG	286	NLA_PUT_U32(skb, FRA_FWMARK, rule4->fwmark);
1da177e4	287	#endif
e1ef4bf2 TG	288
	289	if (rule4->dst_len)
	290	NLA_PUT_U32(skb, FRA_DST, rule4->dst);
	291
	292	if (rule4->src_len)
	293	NLA_PUT_U32(skb, FRA_SRC, rule4->src);
	294
1da177e4	295	#ifdef CONFIG_NET_CLS_ROUTE
e1ef4bf2 TG	296	if (rule4->tclassid)
e1ef4bf2 TG	297	NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid);
1da177e4	298	#endif
e1ef4bf2	299	return 0;
1da177e4	300
e1ef4bf2 TG	301	nla_put_failure:
e1ef4bf2 TG	302	return -ENOBUFS;
1da177e4 LT	303	}
1da177e4 LT	304
e1ef4bf2 TG	305	int fib4_rules_dump(struct sk_buff skb, struct netlink_callback cb)
	306	{
	307	return fib_rules_dump(skb, cb, AF_INET);
	308	}
7b204afd	309
e1ef4bf2	310	static u32 fib4_rule_default_pref(void)
a5cdc030	311	{
e1ef4bf2 TG	312	struct list_head *pos;
	313	struct fib_rule *rule;
	314
	315	if (!list_empty(&fib4_rules)) {
	316	pos = fib4_rules.next;
	317	if (pos->next != &fib4_rules) {
	318	rule = list_entry(pos->next, struct fib_rule, list);
	319	if (rule->pref)
	320	return rule->pref - 1;
	321	}
a5cdc030	322	}
e1ef4bf2 TG	323
e1ef4bf2 TG	324	return 0;
a5cdc030 PM	325	}
a5cdc030 PM	326
e1ef4bf2 TG	327	static struct fib_rules_ops fib4_rules_ops = {
	328	.family = AF_INET,
	329	.rule_size = sizeof(struct fib4_rule),
	330	.action = fib4_rule_action,
	331	.match = fib4_rule_match,
	332	.configure = fib4_rule_configure,
	333	.compare = fib4_rule_compare,
	334	.fill = fib4_rule_fill,
	335	.default_pref = fib4_rule_default_pref,
	336	.nlgroup = RTNLGRP_IPV4_RULE,
	337	.policy = fib4_rule_policy,
	338	.rules_list = &fib4_rules,
	339	.owner = THIS_MODULE,
	340	};
	341
	342	void __init fib4_rules_init(void)
1da177e4	343	{
e1ef4bf2 TG	344	list_add_tail(&local_rule.common.list, &fib4_rules);
	345	list_add_tail(&main_rule.common.list, &fib4_rules);
	346	list_add_tail(&default_rule.common.list, &fib4_rules);
1da177e4	347
e1ef4bf2	348	fib_rules_register(&fib4_rules_ops);
1da177e4 LT	349	}
1da177e4 LT	350
e1ef4bf2	351	void __exit fib4_rules_cleanup(void)
1da177e4	352	{
e1ef4bf2	353	fib_rules_unregister(&fib4_rules_ops);
1da177e4	354	}