[mirror_ubuntu-jammy-kernel.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.
 *
 * Version:	$Id: fib_rules.c,v 1.17 2001/10/31 21:55:54 davem Exp $
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 *		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 <asm/uaccess.h>
#include <asm/system.h>
#include <linux/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/proc_fs.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/rcupdate.h>

#include <net/ip.h>
#include <net/protocol.h>
#include <net/route.h>
#include <net/tcp.h>
#include <net/sock.h>
#include <net/ip_fib.h>

#define FRprintk(a...)

struct fib_rule
{
	struct hlist_node hlist;
	atomic_t	r_clntref;
	u32		r_preference;
	unsigned char	r_table;
	unsigned char	r_action;
	unsigned char	r_dst_len;
	unsigned char	r_src_len;
	u32		r_src;
	u32		r_srcmask;
	u32		r_dst;
	u32		r_dstmask;
	u32		r_srcmap;
	u8		r_flags;
	u8		r_tos;
#ifdef CONFIG_IP_ROUTE_FWMARK
	u32		r_fwmark;
#endif
	int		r_ifindex;
#ifdef CONFIG_NET_CLS_ROUTE
	__u32		r_tclassid;
#endif
	char		r_ifname[IFNAMSIZ];
	int		r_dead;
	struct		rcu_head rcu;
};

static struct fib_rule default_rule = {
	.r_clntref =	ATOMIC_INIT(2),
	.r_preference =	0x7FFF,
	.r_table =	RT_TABLE_DEFAULT,
	.r_action =	RTN_UNICAST,
};

static struct fib_rule main_rule = {
	.r_clntref =	ATOMIC_INIT(2),
	.r_preference =	0x7FFE,
	.r_table =	RT_TABLE_MAIN,
	.r_action =	RTN_UNICAST,
};

static struct fib_rule local_rule = {
	.r_clntref =	ATOMIC_INIT(2),
	.r_table =	RT_TABLE_LOCAL,
	.r_action =	RTN_UNICAST,
};

static struct hlist_head fib_rules;

/* writer func called from netlink -- rtnl_sem hold*/

static void rtmsg_rule(int, struct fib_rule *);

int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
{
	struct rtattr **rta = arg;
	struct rtmsg *rtm = NLMSG_DATA(nlh);
	struct fib_rule *r;
	struct hlist_node *node;
	int err = -ESRCH;

	hlist_for_each_entry(r, node, &fib_rules, hlist) {
		if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 4) == 0) &&
		    rtm->rtm_src_len == r->r_src_len &&
		    rtm->rtm_dst_len == r->r_dst_len &&
		    (!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 4) == 0) &&
		    rtm->rtm_tos == r->r_tos &&
#ifdef CONFIG_IP_ROUTE_FWMARK
		    (!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) &&
#endif
		    (!rtm->rtm_type || rtm->rtm_type == r->r_action) &&
		    (!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) &&
		    (!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) &&
		    (!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) {
			err = -EPERM;
			if (r == &local_rule)
				break;

			hlist_del_rcu(&r->hlist);
			r->r_dead = 1;
			rtmsg_rule(RTM_DELRULE, r);
			fib_rule_put(r);
			err = 0;
			break;
		}
	}
	return err;
}

/* Allocate new unique table id */

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 inline void fib_rule_put_rcu(struct rcu_head *head)
{
	struct fib_rule *r = container_of(head, struct fib_rule, rcu);
	kfree(r);
}

void fib_rule_put(struct fib_rule *r)
{
	if (atomic_dec_and_test(&r->r_clntref)) {
		if (r->r_dead)
			call_rcu(&r->rcu, fib_rule_put_rcu);
		else
			printk("Freeing alive rule %p\n", r);
	}
}

/* writer func called from netlink -- rtnl_sem hold*/

int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
{
	struct rtattr **rta = arg;
	struct rtmsg *rtm = NLMSG_DATA(nlh);
	struct fib_rule *r, *new_r, *last = NULL;
	struct hlist_node *node = NULL;
	unsigned char table_id;

	if (rtm->rtm_src_len > 32 || rtm->rtm_dst_len > 32 ||
	    (rtm->rtm_tos & ~IPTOS_TOS_MASK))
		return -EINVAL;

	if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ)
		return -EINVAL;

	table_id = rtm->rtm_table;
	if (table_id == RT_TABLE_UNSPEC) {
		struct fib_table *table;
		if (rtm->rtm_type == RTN_UNICAST) {
			if ((table = fib_empty_table()) == NULL)
				return -ENOBUFS;
			table_id = table->tb_id;
		}
	}

	new_r = kmalloc(sizeof(*new_r), GFP_KERNEL);
	if (!new_r)
		return -ENOMEM;
	memset(new_r, 0, sizeof(*new_r));

	if (rta[RTA_SRC-1])
		memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 4);
	if (rta[RTA_DST-1])
		memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 4);
	if (rta[RTA_GATEWAY-1])
		memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 4);
	new_r->r_src_len = rtm->rtm_src_len;
	new_r->r_dst_len = rtm->rtm_dst_len;
	new_r->r_srcmask = inet_make_mask(rtm->rtm_src_len);
	new_r->r_dstmask = inet_make_mask(rtm->rtm_dst_len);
	new_r->r_tos = rtm->rtm_tos;
#ifdef CONFIG_IP_ROUTE_FWMARK
	if (rta[RTA_PROTOINFO-1])
		memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4);
#endif
	new_r->r_action = rtm->rtm_type;
	new_r->r_flags = rtm->rtm_flags;
	if (rta[RTA_PRIORITY-1])
		memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4);
	new_r->r_table = table_id;
	if (rta[RTA_IIF-1]) {
		struct net_device *dev;
		rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ);
		new_r->r_ifindex = -1;
		dev = __dev_get_by_name(new_r->r_ifname);
		if (dev)
			new_r->r_ifindex = dev->ifindex;
	}
#ifdef CONFIG_NET_CLS_ROUTE
	if (rta[RTA_FLOW-1])
		memcpy(&new_r->r_tclassid, RTA_DATA(rta[RTA_FLOW-1]), 4);
#endif
	r = container_of(fib_rules.first, struct fib_rule, hlist);

	if (!new_r->r_preference) {
		if (r && r->hlist.next != NULL) {
			r = container_of(r->hlist.next, struct fib_rule, hlist);
			if (r->r_preference)
				new_r->r_preference = r->r_preference - 1;
		}
	}

	hlist_for_each_entry(r, node, &fib_rules, hlist) {
		if (r->r_preference > new_r->r_preference)
			break;
		last = r;
	}
	atomic_inc(&new_r->r_clntref);

	if (last)
		hlist_add_after_rcu(&last->hlist, &new_r->hlist);
	else
		hlist_add_before_rcu(&new_r->hlist, &r->hlist);

	rtmsg_rule(RTM_NEWRULE, new_r);
	return 0;
}

#ifdef CONFIG_NET_CLS_ROUTE
u32 fib_rules_tclass(struct fib_result *res)
{
	if (res->r)
		return res->r->r_tclassid;
	return 0;
}
#endif

/* callers should hold rtnl semaphore */

static void fib_rules_detach(struct net_device *dev)
{
	struct hlist_node *node;
	struct fib_rule *r;

	hlist_for_each_entry(r, node, &fib_rules, hlist) {
		if (r->r_ifindex == dev->ifindex)
			r->r_ifindex = -1;

	}
}

/* callers should hold rtnl semaphore */

static void fib_rules_attach(struct net_device *dev)
{
	struct hlist_node *node;
	struct fib_rule *r;

	hlist_for_each_entry(r, node, &fib_rules, hlist) {
		if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0)
			r->r_ifindex = dev->ifindex;
	}
}

int fib_lookup(const struct flowi *flp, struct fib_result *res)
{
	int err;
	struct fib_rule *r, *policy;
	struct fib_table *tb;
	struct hlist_node *node;

	u32 daddr = flp->fl4_dst;
	u32 saddr = flp->fl4_src;

FRprintk("Lookup: %u.%u.%u.%u <- %u.%u.%u.%u ",
	NIPQUAD(flp->fl4_dst), NIPQUAD(flp->fl4_src));

	rcu_read_lock();

	hlist_for_each_entry_rcu(r, node, &fib_rules, hlist) {
		if (((saddr^r->r_src) & r->r_srcmask) ||
		    ((daddr^r->r_dst) & r->r_dstmask) ||
		    (r->r_tos && r->r_tos != flp->fl4_tos) ||
#ifdef CONFIG_IP_ROUTE_FWMARK
		    (r->r_fwmark && r->r_fwmark != flp->fl4_fwmark) ||
#endif
		    (r->r_ifindex && r->r_ifindex != flp->iif))
			continue;

FRprintk("tb %d r %d ", r->r_table, r->r_action);
		switch (r->r_action) {
		case RTN_UNICAST:
			policy = r;
			break;
		case RTN_UNREACHABLE:
			rcu_read_unlock();
			return -ENETUNREACH;
		default:
		case RTN_BLACKHOLE:
			rcu_read_unlock();
			return -EINVAL;
		case RTN_PROHIBIT:
			rcu_read_unlock();
			return -EACCES;
		}

		if ((tb = fib_get_table(r->r_table)) == NULL)
			continue;
		err = tb->tb_lookup(tb, flp, res);
		if (err == 0) {
			res->r = policy;
			if (policy)
				atomic_inc(&policy->r_clntref);
			rcu_read_unlock();
			return 0;
		}
		if (err < 0 && err != -EAGAIN) {
			rcu_read_unlock();
			return err;
		}
	}
FRprintk("FAILURE\n");
	rcu_read_unlock();
	return -ENETUNREACH;
}

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

static int fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr)
{
	struct net_device *dev = ptr;

	if (event == NETDEV_UNREGISTER)
		fib_rules_detach(dev);
	else if (event == NETDEV_REGISTER)
		fib_rules_attach(dev);
	return NOTIFY_DONE;
}


static struct notifier_block fib_rules_notifier = {
	.notifier_call =fib_rules_event,
};

static __inline__ int inet_fill_rule(struct sk_buff *skb,
				     struct fib_rule *r,
				     u32 pid, u32 seq, int event,
				     unsigned int flags)
{
	struct rtmsg *rtm;
	struct nlmsghdr  *nlh;
	unsigned char	 *b = skb->tail;

	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
	rtm = NLMSG_DATA(nlh);
	rtm->rtm_family = AF_INET;
	rtm->rtm_dst_len = r->r_dst_len;
	rtm->rtm_src_len = r->r_src_len;
	rtm->rtm_tos = r->r_tos;
#ifdef CONFIG_IP_ROUTE_FWMARK
	if (r->r_fwmark)
		RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark);
#endif
	rtm->rtm_table = r->r_table;
	rtm->rtm_protocol = 0;
	rtm->rtm_scope = 0;
	rtm->rtm_type = r->r_action;
	rtm->rtm_flags = r->r_flags;

	if (r->r_dst_len)
		RTA_PUT(skb, RTA_DST, 4, &r->r_dst);
	if (r->r_src_len)
		RTA_PUT(skb, RTA_SRC, 4, &r->r_src);
	if (r->r_ifname[0])
		RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname);
	if (r->r_preference)
		RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference);
	if (r->r_srcmap)
		RTA_PUT(skb, RTA_GATEWAY, 4, &r->r_srcmap);
#ifdef CONFIG_NET_CLS_ROUTE
	if (r->r_tclassid)
		RTA_PUT(skb, RTA_FLOW, 4, &r->r_tclassid);
#endif
	nlh->nlmsg_len = skb->tail - b;
	return skb->len;

nlmsg_failure:
rtattr_failure:
	skb_trim(skb, b - skb->data);
	return -1;
}

/* callers should hold rtnl semaphore */

static void rtmsg_rule(int event, struct fib_rule *r)
{
	int size = NLMSG_SPACE(sizeof(struct rtmsg) + 128);
	struct sk_buff *skb = alloc_skb(size, GFP_KERNEL);

	if (!skb)
		netlink_set_err(rtnl, 0, RTNLGRP_IPV4_RULE, ENOBUFS);
	else if (inet_fill_rule(skb, r, 0, 0, event, 0) < 0) {
		kfree_skb(skb);
		netlink_set_err(rtnl, 0, RTNLGRP_IPV4_RULE, EINVAL);
	} else {
		netlink_broadcast(rtnl, skb, 0, RTNLGRP_IPV4_RULE, GFP_KERNEL);
	}
}

int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
{
	int idx = 0;
	int s_idx = cb->args[0];
	struct fib_rule *r;
	struct hlist_node *node;

	rcu_read_lock();
	hlist_for_each_entry(r, node, &fib_rules, hlist) {

		if (idx < s_idx)
			continue;
		if (inet_fill_rule(skb, r, NETLINK_CB(cb->skb).pid,
				   cb->nlh->nlmsg_seq,
				   RTM_NEWRULE, NLM_F_MULTI) < 0)
			break;
		idx++;
	}
	rcu_read_unlock();
	cb->args[0] = idx;

	return skb->len;
}

void __init fib_rules_init(void)
{
	INIT_HLIST_HEAD(&fib_rules);
	hlist_add_head(&local_rule.hlist, &fib_rules);
	hlist_add_after(&local_rule.hlist, &main_rule.hlist);
	hlist_add_after(&main_rule.hlist, &default_rule.hlist);
	register_netdevice_notifier(&fib_rules_notifier);
}
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	*
	8	* Version: $Id: fib_rules.c,v 1.17 2001/10/31 21:55:54 davem Exp $
	9	*
	10	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	11	*
	12	* This program is free software; you can redistribute it and/or
	13	* modify it under the terms of the GNU General Public License
	14	* as published by the Free Software Foundation; either version
	15	* 2 of the License, or (at your option) any later version.
	16	*
	17	* Fixes:
	18	* Rani Assaf : local_rule cannot be deleted
	19	* Marc Boucher : routing by fwmark
	20	*/
	21
1da177e4 LT	22	#include <asm/uaccess.h>
	23	#include <asm/system.h>
	24	#include <linux/bitops.h>
	25	#include <linux/types.h>
	26	#include <linux/kernel.h>
	27	#include <linux/sched.h>
	28	#include <linux/mm.h>
	29	#include <linux/string.h>
	30	#include <linux/socket.h>
	31	#include <linux/sockios.h>
	32	#include <linux/errno.h>
	33	#include <linux/in.h>
	34	#include <linux/inet.h>
14c85021	35	#include <linux/inetdevice.h>
1da177e4 LT	36	#include <linux/netdevice.h>
	37	#include <linux/if_arp.h>
	38	#include <linux/proc_fs.h>
	39	#include <linux/skbuff.h>
	40	#include <linux/netlink.h>
	41	#include <linux/init.h>
7b204afd RO	42	#include <linux/list.h>
7b204afd RO	43	#include <linux/rcupdate.h>
1da177e4 LT	44
	45	#include <net/ip.h>
	46	#include <net/protocol.h>
	47	#include <net/route.h>
	48	#include <net/tcp.h>
	49	#include <net/sock.h>
	50	#include <net/ip_fib.h>
	51
	52	#define FRprintk(a...)
	53
	54	struct fib_rule
	55	{
7b204afd	56	struct hlist_node hlist;
1da177e4 LT	57	atomic_t r_clntref;
	58	u32 r_preference;
	59	unsigned char r_table;
	60	unsigned char r_action;
	61	unsigned char r_dst_len;
	62	unsigned char r_src_len;
	63	u32 r_src;
	64	u32 r_srcmask;
	65	u32 r_dst;
	66	u32 r_dstmask;
	67	u32 r_srcmap;
	68	u8 r_flags;
	69	u8 r_tos;
	70	#ifdef CONFIG_IP_ROUTE_FWMARK
	71	u32 r_fwmark;
	72	#endif
	73	int r_ifindex;
	74	#ifdef CONFIG_NET_CLS_ROUTE
	75	__u32 r_tclassid;
	76	#endif
	77	char r_ifname[IFNAMSIZ];
	78	int r_dead;
7b204afd	79	struct rcu_head rcu;
1da177e4 LT	80	};
	81
	82	static struct fib_rule default_rule = {
	83	.r_clntref = ATOMIC_INIT(2),
	84	.r_preference = 0x7FFF,
	85	.r_table = RT_TABLE_DEFAULT,
	86	.r_action = RTN_UNICAST,
	87	};
	88
	89	static struct fib_rule main_rule = {
1da177e4 LT	90	.r_clntref = ATOMIC_INIT(2),
	91	.r_preference = 0x7FFE,
	92	.r_table = RT_TABLE_MAIN,
	93	.r_action = RTN_UNICAST,
	94	};
	95
	96	static struct fib_rule local_rule = {
1da177e4 LT	97	.r_clntref = ATOMIC_INIT(2),
	98	.r_table = RT_TABLE_LOCAL,
	99	.r_action = RTN_UNICAST,
	100	};
	101
d15150f7	102	static struct hlist_head fib_rules;
7b204afd RO	103
7b204afd RO	104	/* writer func called from netlink -- rtnl_sem hold*/
1da177e4	105
a5cdc030 PM	106	static void rtmsg_rule(int, struct fib_rule *);
a5cdc030 PM	107
1da177e4 LT	108	int inet_rtm_delrule(struct sk_buff skb, struct nlmsghdr nlh, void *arg)
	109	{
	110	struct rtattr **rta = arg;
	111	struct rtmsg *rtm = NLMSG_DATA(nlh);
7b204afd RO	112	struct fib_rule *r;
7b204afd RO	113	struct hlist_node *node;
1da177e4 LT	114	int err = -ESRCH;
1da177e4 LT	115
7b204afd	116	hlist_for_each_entry(r, node, &fib_rules, hlist) {
1da177e4 LT	117	if ((!rta[RTA_SRC-1] \|\| memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 4) == 0) &&
	118	rtm->rtm_src_len == r->r_src_len &&
	119	rtm->rtm_dst_len == r->r_dst_len &&
	120	(!rta[RTA_DST-1] \|\| memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 4) == 0) &&
	121	rtm->rtm_tos == r->r_tos &&
	122	#ifdef CONFIG_IP_ROUTE_FWMARK
	123	(!rta[RTA_PROTOINFO-1] \|\| memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) &&
	124	#endif
	125	(!rtm->rtm_type \|\| rtm->rtm_type == r->r_action) &&
	126	(!rta[RTA_PRIORITY-1] \|\| memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) &&
	127	(!rta[RTA_IIF-1] \|\| rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) &&
	128	(!rtm->rtm_table \|\| (r && rtm->rtm_table == r->r_table))) {
	129	err = -EPERM;
	130	if (r == &local_rule)
	131	break;
	132
7b204afd	133	hlist_del_rcu(&r->hlist);
1da177e4	134	r->r_dead = 1;
a5cdc030	135	rtmsg_rule(RTM_DELRULE, r);
1da177e4 LT	136	fib_rule_put(r);
	137	err = 0;
	138	break;
	139	}
	140	}
	141	return err;
	142	}
	143
	144	/* Allocate new unique table id */
	145
	146	static struct fib_table *fib_empty_table(void)
	147	{
	148	int id;
	149
	150	for (id = 1; id <= RT_TABLE_MAX; id++)
	151	if (fib_tables[id] == NULL)
	152	return __fib_new_table(id);
	153	return NULL;
	154	}
	155
7b204afd RO	156	static inline void fib_rule_put_rcu(struct rcu_head *head)
	157	{
	158	struct fib_rule *r = container_of(head, struct fib_rule, rcu);
	159	kfree(r);
	160	}
	161
1da177e4 LT	162	void fib_rule_put(struct fib_rule *r)
	163	{
	164	if (atomic_dec_and_test(&r->r_clntref)) {
	165	if (r->r_dead)
7b204afd	166	call_rcu(&r->rcu, fib_rule_put_rcu);
1da177e4 LT	167	else
	168	printk("Freeing alive rule %p\n", r);
	169	}
	170	}
	171
7b204afd RO	172	/* writer func called from netlink -- rtnl_sem hold*/
7b204afd RO	173
1da177e4 LT	174	int inet_rtm_newrule(struct sk_buff skb, struct nlmsghdr nlh, void *arg)
	175	{
	176	struct rtattr **rta = arg;
	177	struct rtmsg *rtm = NLMSG_DATA(nlh);
7b204afd RO	178	struct fib_rule r, new_r, *last = NULL;
7b204afd RO	179	struct hlist_node *node = NULL;
1da177e4 LT	180	unsigned char table_id;
	181
	182	if (rtm->rtm_src_len > 32 \|\| rtm->rtm_dst_len > 32 \|\|
	183	(rtm->rtm_tos & ~IPTOS_TOS_MASK))
	184	return -EINVAL;
	185
	186	if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ)
	187	return -EINVAL;
	188
	189	table_id = rtm->rtm_table;
	190	if (table_id == RT_TABLE_UNSPEC) {
	191	struct fib_table *table;
	192	if (rtm->rtm_type == RTN_UNICAST) {
	193	if ((table = fib_empty_table()) == NULL)
	194	return -ENOBUFS;
	195	table_id = table->tb_id;
	196	}
	197	}
	198
	199	new_r = kmalloc(sizeof(*new_r), GFP_KERNEL);
	200	if (!new_r)
	201	return -ENOMEM;
	202	memset(new_r, 0, sizeof(*new_r));
7b204afd	203
1da177e4 LT	204	if (rta[RTA_SRC-1])
	205	memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 4);
	206	if (rta[RTA_DST-1])
	207	memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 4);
	208	if (rta[RTA_GATEWAY-1])
	209	memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 4);
	210	new_r->r_src_len = rtm->rtm_src_len;
	211	new_r->r_dst_len = rtm->rtm_dst_len;
	212	new_r->r_srcmask = inet_make_mask(rtm->rtm_src_len);
	213	new_r->r_dstmask = inet_make_mask(rtm->rtm_dst_len);
	214	new_r->r_tos = rtm->rtm_tos;
	215	#ifdef CONFIG_IP_ROUTE_FWMARK
	216	if (rta[RTA_PROTOINFO-1])
	217	memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4);
	218	#endif
	219	new_r->r_action = rtm->rtm_type;
	220	new_r->r_flags = rtm->rtm_flags;
	221	if (rta[RTA_PRIORITY-1])
	222	memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4);
	223	new_r->r_table = table_id;
	224	if (rta[RTA_IIF-1]) {
	225	struct net_device *dev;
	226	rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ);
	227	new_r->r_ifindex = -1;
	228	dev = __dev_get_by_name(new_r->r_ifname);
	229	if (dev)
	230	new_r->r_ifindex = dev->ifindex;
	231	}
	232	#ifdef CONFIG_NET_CLS_ROUTE
	233	if (rta[RTA_FLOW-1])
	234	memcpy(&new_r->r_tclassid, RTA_DATA(rta[RTA_FLOW-1]), 4);
	235	#endif
7b204afd	236	r = container_of(fib_rules.first, struct fib_rule, hlist);
1da177e4	237
1da177e4	238	if (!new_r->r_preference) {
7b204afd RO	239	if (r && r->hlist.next != NULL) {
7b204afd RO	240	r = container_of(r->hlist.next, struct fib_rule, hlist);
1da177e4 LT	241	if (r->r_preference)
	242	new_r->r_preference = r->r_preference - 1;
	243	}
	244	}
	245
7b204afd	246	hlist_for_each_entry(r, node, &fib_rules, hlist) {
1da177e4 LT	247	if (r->r_preference > new_r->r_preference)
1da177e4 LT	248	break;
7b204afd	249	last = r;
1da177e4	250	}
1da177e4	251	atomic_inc(&new_r->r_clntref);
7b204afd RO	252
	253	if (last)
	254	hlist_add_after_rcu(&last->hlist, &new_r->hlist);
	255	else
	256	hlist_add_before_rcu(&new_r->hlist, &r->hlist);
	257
a5cdc030	258	rtmsg_rule(RTM_NEWRULE, new_r);
1da177e4 LT	259	return 0;
	260	}
	261
	262	#ifdef CONFIG_NET_CLS_ROUTE
	263	u32 fib_rules_tclass(struct fib_result *res)
	264	{
	265	if (res->r)
	266	return res->r->r_tclassid;
	267	return 0;
	268	}
	269	#endif
	270
7b204afd	271	/* callers should hold rtnl semaphore */
1da177e4 LT	272
	273	static void fib_rules_detach(struct net_device *dev)
	274	{
7b204afd	275	struct hlist_node *node;
1da177e4 LT	276	struct fib_rule *r;
1da177e4 LT	277
7b204afd RO	278	hlist_for_each_entry(r, node, &fib_rules, hlist) {
7b204afd RO	279	if (r->r_ifindex == dev->ifindex)
1da177e4	280	r->r_ifindex = -1;
7b204afd	281
1da177e4 LT	282	}
	283	}
	284
7b204afd RO	285	/* callers should hold rtnl semaphore */
7b204afd RO	286
1da177e4 LT	287	static void fib_rules_attach(struct net_device *dev)
1da177e4 LT	288	{
7b204afd	289	struct hlist_node *node;
1da177e4 LT	290	struct fib_rule *r;
1da177e4 LT	291
7b204afd RO	292	hlist_for_each_entry(r, node, &fib_rules, hlist) {
7b204afd RO	293	if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0)
1da177e4	294	r->r_ifindex = dev->ifindex;
1da177e4 LT	295	}
	296	}
	297
	298	int fib_lookup(const struct flowi flp, struct fib_result res)
	299	{
	300	int err;
	301	struct fib_rule r, policy;
	302	struct fib_table *tb;
7b204afd	303	struct hlist_node *node;
1da177e4 LT	304
	305	u32 daddr = flp->fl4_dst;
	306	u32 saddr = flp->fl4_src;
	307
	308	FRprintk("Lookup: %u.%u.%u.%u <- %u.%u.%u.%u ",
	309	NIPQUAD(flp->fl4_dst), NIPQUAD(flp->fl4_src));
7b204afd RO	310
	311	rcu_read_lock();
	312
	313	hlist_for_each_entry_rcu(r, node, &fib_rules, hlist) {
1da177e4 LT	314	if (((saddr^r->r_src) & r->r_srcmask) \|\|
	315	((daddr^r->r_dst) & r->r_dstmask) \|\|
	316	(r->r_tos && r->r_tos != flp->fl4_tos) \|\|
	317	#ifdef CONFIG_IP_ROUTE_FWMARK
	318	(r->r_fwmark && r->r_fwmark != flp->fl4_fwmark) \|\|
	319	#endif
	320	(r->r_ifindex && r->r_ifindex != flp->iif))
	321	continue;
	322
	323	FRprintk("tb %d r %d ", r->r_table, r->r_action);
	324	switch (r->r_action) {
	325	case RTN_UNICAST:
	326	policy = r;
	327	break;
	328	case RTN_UNREACHABLE:
7b204afd	329	rcu_read_unlock();
1da177e4 LT	330	return -ENETUNREACH;
	331	default:
	332	case RTN_BLACKHOLE:
7b204afd	333	rcu_read_unlock();
1da177e4 LT	334	return -EINVAL;
1da177e4 LT	335	case RTN_PROHIBIT:
7b204afd	336	rcu_read_unlock();
1da177e4 LT	337	return -EACCES;
	338	}
	339
	340	if ((tb = fib_get_table(r->r_table)) == NULL)
	341	continue;
	342	err = tb->tb_lookup(tb, flp, res);
	343	if (err == 0) {
	344	res->r = policy;
	345	if (policy)
	346	atomic_inc(&policy->r_clntref);
7b204afd	347	rcu_read_unlock();
1da177e4 LT	348	return 0;
	349	}
	350	if (err < 0 && err != -EAGAIN) {
7b204afd	351	rcu_read_unlock();
1da177e4 LT	352	return err;
	353	}
	354	}
	355	FRprintk("FAILURE\n");
7b204afd	356	rcu_read_unlock();
1da177e4 LT	357	return -ENETUNREACH;
	358	}
	359
	360	void fib_select_default(const struct flowi flp, struct fib_result res)
	361	{
	362	if (res->r && res->r->r_action == RTN_UNICAST &&
	363	FIB_RES_GW(res) && FIB_RES_NH(res).nh_scope == RT_SCOPE_LINK) {
	364	struct fib_table *tb;
	365	if ((tb = fib_get_table(res->r->r_table)) != NULL)
	366	tb->tb_select_default(tb, flp, res);
	367	}
	368	}
	369
	370	static int fib_rules_event(struct notifier_block this, unsigned long event, void ptr)
	371	{
	372	struct net_device *dev = ptr;
	373
	374	if (event == NETDEV_UNREGISTER)
	375	fib_rules_detach(dev);
	376	else if (event == NETDEV_REGISTER)
	377	fib_rules_attach(dev);
	378	return NOTIFY_DONE;
	379	}
	380
	381
	382	static struct notifier_block fib_rules_notifier = {
	383	.notifier_call =fib_rules_event,
	384	};
	385
	386	static __inline__ int inet_fill_rule(struct sk_buff *skb,
	387	struct fib_rule *r,
a5cdc030	388	u32 pid, u32 seq, int event,
b6544c0b	389	unsigned int flags)
1da177e4 LT	390	{
	391	struct rtmsg *rtm;
	392	struct nlmsghdr *nlh;
	393	unsigned char *b = skb->tail;
	394
a5cdc030	395	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
1da177e4 LT	396	rtm = NLMSG_DATA(nlh);
	397	rtm->rtm_family = AF_INET;
	398	rtm->rtm_dst_len = r->r_dst_len;
	399	rtm->rtm_src_len = r->r_src_len;
	400	rtm->rtm_tos = r->r_tos;
	401	#ifdef CONFIG_IP_ROUTE_FWMARK
	402	if (r->r_fwmark)
	403	RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark);
	404	#endif
	405	rtm->rtm_table = r->r_table;
	406	rtm->rtm_protocol = 0;
	407	rtm->rtm_scope = 0;
	408	rtm->rtm_type = r->r_action;
	409	rtm->rtm_flags = r->r_flags;
	410
	411	if (r->r_dst_len)
	412	RTA_PUT(skb, RTA_DST, 4, &r->r_dst);
	413	if (r->r_src_len)
	414	RTA_PUT(skb, RTA_SRC, 4, &r->r_src);
	415	if (r->r_ifname[0])
	416	RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname);
	417	if (r->r_preference)
	418	RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference);
	419	if (r->r_srcmap)
	420	RTA_PUT(skb, RTA_GATEWAY, 4, &r->r_srcmap);
	421	#ifdef CONFIG_NET_CLS_ROUTE
	422	if (r->r_tclassid)
	423	RTA_PUT(skb, RTA_FLOW, 4, &r->r_tclassid);
	424	#endif
	425	nlh->nlmsg_len = skb->tail - b;
	426	return skb->len;
	427
	428	nlmsg_failure:
	429	rtattr_failure:
	430	skb_trim(skb, b - skb->data);
	431	return -1;
	432	}
	433
7b204afd RO	434	/* callers should hold rtnl semaphore */
7b204afd RO	435
a5cdc030 PM	436	static void rtmsg_rule(int event, struct fib_rule *r)
	437	{
	438	int size = NLMSG_SPACE(sizeof(struct rtmsg) + 128);
	439	struct sk_buff *skb = alloc_skb(size, GFP_KERNEL);
	440
	441	if (!skb)
	442	netlink_set_err(rtnl, 0, RTNLGRP_IPV4_RULE, ENOBUFS);
	443	else if (inet_fill_rule(skb, r, 0, 0, event, 0) < 0) {
	444	kfree_skb(skb);
	445	netlink_set_err(rtnl, 0, RTNLGRP_IPV4_RULE, EINVAL);
	446	} else {
	447	netlink_broadcast(rtnl, skb, 0, RTNLGRP_IPV4_RULE, GFP_KERNEL);
	448	}
	449	}
	450
1da177e4 LT	451	int inet_dump_rules(struct sk_buff skb, struct netlink_callback cb)
1da177e4 LT	452	{
7b204afd	453	int idx = 0;
1da177e4 LT	454	int s_idx = cb->args[0];
1da177e4 LT	455	struct fib_rule *r;
7b204afd RO	456	struct hlist_node *node;
	457
	458	rcu_read_lock();
	459	hlist_for_each_entry(r, node, &fib_rules, hlist) {
1da177e4	460
1da177e4 LT	461	if (idx < s_idx)
1da177e4 LT	462	continue;
a5cdc030 PM	463	if (inet_fill_rule(skb, r, NETLINK_CB(cb->skb).pid,
	464	cb->nlh->nlmsg_seq,
	465	RTM_NEWRULE, NLM_F_MULTI) < 0)
1da177e4	466	break;
7b204afd	467	idx++;
1da177e4	468	}
7b204afd	469	rcu_read_unlock();
1da177e4 LT	470	cb->args[0] = idx;
	471
	472	return skb->len;
	473	}
	474
	475	void __init fib_rules_init(void)
	476	{
7b204afd RO	477	INIT_HLIST_HEAD(&fib_rules);
	478	hlist_add_head(&local_rule.hlist, &fib_rules);
	479	hlist_add_after(&local_rule.hlist, &main_rule.hlist);
	480	hlist_add_after(&main_rule.hlist, &default_rule.hlist);
1da177e4 LT	481	register_netdevice_notifier(&fib_rules_notifier);
1da177e4 LT	482	}