[mirror_ubuntu-jammy-kernel.git] / net / decnet / dn_rules.c

// SPDX-License-Identifier: GPL-2.0

/*
 * DECnet       An implementation of the DECnet protocol suite for the LINUX
 *              operating system.  DECnet is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              DECnet Routing Forwarding Information Base (Rules)
 *
 * Author:      Steve Whitehouse <SteveW@ACM.org>
 *              Mostly copied from Alexey Kuznetsov's ipv4/fib_rules.c
 *
 *
 * Changes:
 *              Steve Whitehouse <steve@chygwyn.com>
 *              Updated for Thomas Graf's generic rules
 *
 */
#include <linux/net.h>
#include <linux/init.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/rcupdate.h>
#include <linux/export.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/fib_rules.h>
#include <net/dn.h>
#include <net/dn_fib.h>
#include <net/dn_neigh.h>
#include <net/dn_dev.h>
#include <net/dn_route.h>

static struct fib_rules_ops *dn_fib_rules_ops;

struct dn_fib_rule
{
	struct fib_rule		common;
	unsigned char		dst_len;
	unsigned char		src_len;
	__le16			src;
	__le16			srcmask;
	__le16			dst;
	__le16			dstmask;
	__le16			srcmap;
	u8			flags;
};


int dn_fib_lookup(struct flowidn *flp, struct dn_fib_res *res)
{
	struct fib_lookup_arg arg = {
		.result = res,
	};
	int err;

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

	return err;
}

static int dn_fib_rule_action(struct fib_rule *rule, struct flowi *flp,
			      int flags, struct fib_lookup_arg *arg)
{
	struct flowidn *fld = &flp->u.dn;
	int err = -EAGAIN;
	struct dn_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;
	}

	tbl = dn_fib_get_table(rule->table, 0);
	if (tbl == NULL)
		goto errout;

	err = tbl->lookup(tbl, fld, (struct dn_fib_res *)arg->result);
	if (err > 0)
		err = -EAGAIN;
errout:
	return err;
}

static const struct nla_policy dn_fib_rule_policy[FRA_MAX+1] = {
	FRA_GENERIC_POLICY,
};

static int dn_fib_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
{
	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
	struct flowidn *fld = &fl->u.dn;
	__le16 daddr = fld->daddr;
	__le16 saddr = fld->saddr;

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

	return 1;
}

static int dn_fib_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
				 struct fib_rule_hdr *frh,
				 struct nlattr **tb,
				 struct netlink_ext_ack *extack)
{
	int err = -EINVAL;
	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;

	if (frh->tos) {
		NL_SET_ERR_MSG(extack, "Invalid tos value");
		goto  errout;
	}

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

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

			rule->table = table->n;
		}
	}

	if (frh->src_len)
		r->src = nla_get_le16(tb[FRA_SRC]);

	if (frh->dst_len)
		r->dst = nla_get_le16(tb[FRA_DST]);

	r->src_len = frh->src_len;
	r->srcmask = dnet_make_mask(r->src_len);
	r->dst_len = frh->dst_len;
	r->dstmask = dnet_make_mask(r->dst_len);
	err = 0;
errout:
	return err;
}

static int dn_fib_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
			       struct nlattr **tb)
{
	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;

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

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

	if (frh->src_len && (r->src != nla_get_le16(tb[FRA_SRC])))
		return 0;

	if (frh->dst_len && (r->dst != nla_get_le16(tb[FRA_DST])))
		return 0;

	return 1;
}

unsigned int dnet_addr_type(__le16 addr)
{
	struct flowidn fld = { .daddr = addr };
	struct dn_fib_res res;
	unsigned int ret = RTN_UNICAST;
	struct dn_fib_table *tb = dn_fib_get_table(RT_TABLE_LOCAL, 0);

	res.r = NULL;

	if (tb) {
		if (!tb->lookup(tb, &fld, &res)) {
			ret = res.type;
			dn_fib_res_put(&res);
		}
	}
	return ret;
}

static int dn_fib_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
			    struct fib_rule_hdr *frh)
{
	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;

	frh->dst_len = r->dst_len;
	frh->src_len = r->src_len;
	frh->tos = 0;

	if ((r->dst_len &&
	     nla_put_le16(skb, FRA_DST, r->dst)) ||
	    (r->src_len &&
	     nla_put_le16(skb, FRA_SRC, r->src)))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -ENOBUFS;
}

static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops)
{
	dn_rt_cache_flush(-1);
}

static const struct fib_rules_ops __net_initconst dn_fib_rules_ops_template = {
	.family		= AF_DECnet,
	.rule_size	= sizeof(struct dn_fib_rule),
	.addr_size	= sizeof(u16),
	.action		= dn_fib_rule_action,
	.match		= dn_fib_rule_match,
	.configure	= dn_fib_rule_configure,
	.compare	= dn_fib_rule_compare,
	.fill		= dn_fib_rule_fill,
	.flush_cache	= dn_fib_rule_flush_cache,
	.nlgroup	= RTNLGRP_DECnet_RULE,
	.policy		= dn_fib_rule_policy,
	.owner		= THIS_MODULE,
	.fro_net	= &init_net,
};

void __init dn_fib_rules_init(void)
{
	dn_fib_rules_ops =
		fib_rules_register(&dn_fib_rules_ops_template, &init_net);
	BUG_ON(IS_ERR(dn_fib_rules_ops));
	BUG_ON(fib_default_rule_add(dn_fib_rules_ops, 0x7fff,
			            RT_TABLE_MAIN, 0));
}

void __exit dn_fib_rules_cleanup(void)
{
	rtnl_lock();
	fib_rules_unregister(dn_fib_rules_ops);
	rtnl_unlock();
	rcu_barrier();
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2
	3	/*
	4	* DECnet An implementation of the DECnet protocol suite for the LINUX
	5	* operating system. DECnet is implemented using the BSD Socket
	6	* interface as the means of communication with the user level.
	7	*
	8	* DECnet Routing Forwarding Information Base (Rules)
	9	*
	10	* Author: Steve Whitehouse <SteveW@ACM.org>
	11	* Mostly copied from Alexey Kuznetsov's ipv4/fib_rules.c
	12	*
	13	*
	14	* Changes:
a8731cbf SW	15	* Steve Whitehouse <steve@chygwyn.com>
a8731cbf SW	16	* Updated for Thomas Graf's generic rules
1da177e4 LT	17	*
1da177e4 LT	18	*/
1da177e4	19	#include <linux/net.h>
1da177e4	20	#include <linux/init.h>
1da177e4 LT	21	#include <linux/netlink.h>
1da177e4 LT	22	#include <linux/rtnetlink.h>
1da177e4	23	#include <linux/netdevice.h>
1da177e4	24	#include <linux/spinlock.h>
ecba320f SW	25	#include <linux/list.h>
ecba320f SW	26	#include <linux/rcupdate.h>
bc3b2d7f	27	#include <linux/export.h>
1da177e4 LT	28	#include <net/neighbour.h>
	29	#include <net/dst.h>
	30	#include <net/flow.h>
a8731cbf	31	#include <net/fib_rules.h>
1da177e4 LT	32	#include <net/dn.h>
	33	#include <net/dn_fib.h>
	34	#include <net/dn_neigh.h>
	35	#include <net/dn_dev.h>
73417f61	36	#include <net/dn_route.h>
1da177e4	37
e9c5158a	38	static struct fib_rules_ops *dn_fib_rules_ops;
a8731cbf	39
1da177e4 LT	40	struct dn_fib_rule
1da177e4 LT	41	{
a8731cbf SW	42	struct fib_rule common;
	43	unsigned char dst_len;
	44	unsigned char src_len;
	45	__le16 src;
	46	__le16 srcmask;
	47	__le16 dst;
	48	__le16 dstmask;
	49	__le16 srcmap;
	50	u8 flags;
1da177e4 LT	51	};
1da177e4 LT	52
1da177e4	53
bef55aeb	54	int dn_fib_lookup(struct flowidn flp, struct dn_fib_res res)
1da177e4	55	{
a8731cbf SW	56	struct fib_lookup_arg arg = {
	57	.result = res,
	58	};
	59	int err;
	60
bef55aeb DM	61	err = fib_rules_lookup(dn_fib_rules_ops,
bef55aeb DM	62	flowidn_to_flowi(flp), 0, &arg);
a8731cbf	63	res->r = arg.rule;
1da177e4 LT	64
	65	return err;
	66	}
	67
2aa7f36c AB	68	static int dn_fib_rule_action(struct fib_rule rule, struct flowi flp,
2aa7f36c AB	69	int flags, struct fib_lookup_arg *arg)
ecba320f	70	{
bef55aeb	71	struct flowidn *fld = &flp->u.dn;
a8731cbf SW	72	int err = -EAGAIN;
a8731cbf SW	73	struct dn_fib_table *tbl;
ecba320f	74
a8731cbf SW	75	switch(rule->action) {
	76	case FR_ACT_TO_TBL:
	77	break;
	78
	79	case FR_ACT_UNREACHABLE:
	80	err = -ENETUNREACH;
	81	goto errout;
	82
	83	case FR_ACT_PROHIBIT:
	84	err = -EACCES;
	85	goto errout;
	86
	87	case FR_ACT_BLACKHOLE:
	88	default:
	89	err = -EINVAL;
	90	goto errout;
1da177e4	91	}
a8731cbf SW	92
	93	tbl = dn_fib_get_table(rule->table, 0);
	94	if (tbl == NULL)
	95	goto errout;
	96
bef55aeb	97	err = tbl->lookup(tbl, fld, (struct dn_fib_res *)arg->result);
a8731cbf SW	98	if (err > 0)
	99	err = -EAGAIN;
	100	errout:
	101	return err;
1da177e4 LT	102	}
1da177e4 LT	103
ef7c79ed	104	static const struct nla_policy dn_fib_rule_policy[FRA_MAX+1] = {
1f6c9557	105	FRA_GENERIC_POLICY,
a8731cbf	106	};
1da177e4	107
a8731cbf	108	static int dn_fib_rule_match(struct fib_rule rule, struct flowi fl, int flags)
1da177e4	109	{
a8731cbf	110	struct dn_fib_rule r = (struct dn_fib_rule )rule;
bef55aeb DM	111	struct flowidn *fld = &fl->u.dn;
	112	__le16 daddr = fld->daddr;
	113	__le16 saddr = fld->saddr;
a8731cbf SW	114
	115	if (((saddr ^ r->src) & r->srcmask) \|\|
	116	((daddr ^ r->dst) & r->dstmask))
	117	return 0;
1da177e4	118
a8731cbf SW	119	return 1;
	120	}
	121
	122	static int dn_fib_rule_configure(struct fib_rule rule, struct sk_buff skb,
8b3521ee	123	struct fib_rule_hdr *frh,
b16fb418 RP	124	struct nlattr **tb,
b16fb418 RP	125	struct netlink_ext_ack *extack)
a8731cbf SW	126	{
	127	int err = -EINVAL;
	128	struct dn_fib_rule r = (struct dn_fib_rule )rule;
	129
b16fb418 RP	130	if (frh->tos) {
b16fb418 RP	131	NL_SET_ERR_MSG(extack, "Invalid tos value");
a8731cbf	132	goto errout;
b16fb418	133	}
a8731cbf SW	134
	135	if (rule->table == RT_TABLE_UNSPEC) {
	136	if (rule->action == FR_ACT_TO_TBL) {
	137	struct dn_fib_table *table;
	138
	139	table = dn_fib_empty_table();
	140	if (table == NULL) {
	141	err = -ENOBUFS;
	142	goto errout;
	143	}
	144
	145	rule->table = table->n;
1da177e4 LT	146	}
	147	}
	148
e1701c68	149	if (frh->src_len)
2835fdfa	150	r->src = nla_get_le16(tb[FRA_SRC]);
ecba320f	151
e1701c68	152	if (frh->dst_len)
2835fdfa	153	r->dst = nla_get_le16(tb[FRA_DST]);
1da177e4	154
a8731cbf SW	155	r->src_len = frh->src_len;
	156	r->srcmask = dnet_make_mask(r->src_len);
	157	r->dst_len = frh->dst_len;
	158	r->dstmask = dnet_make_mask(r->dst_len);
	159	err = 0;
	160	errout:
	161	return err;
	162	}
1da177e4	163
a8731cbf SW	164	static int dn_fib_rule_compare(struct fib_rule rule, struct fib_rule_hdr frh,
a8731cbf SW	165	struct nlattr **tb)
1da177e4	166	{
a8731cbf SW	167	struct dn_fib_rule r = (struct dn_fib_rule )rule;
	168
	169	if (frh->src_len && (r->src_len != frh->src_len))
	170	return 0;
1da177e4	171
a8731cbf SW	172	if (frh->dst_len && (r->dst_len != frh->dst_len))
a8731cbf SW	173	return 0;
ecba320f	174
e1701c68	175	if (frh->src_len && (r->src != nla_get_le16(tb[FRA_SRC])))
a8731cbf SW	176	return 0;
a8731cbf SW	177
e1701c68	178	if (frh->dst_len && (r->dst != nla_get_le16(tb[FRA_DST])))
a8731cbf	179	return 0;
1da177e4	180
a8731cbf	181	return 1;
1da177e4 LT	182	}
1da177e4 LT	183
95c96174	184	unsigned int dnet_addr_type(__le16 addr)
1da177e4	185	{
bef55aeb	186	struct flowidn fld = { .daddr = addr };
1da177e4	187	struct dn_fib_res res;
95c96174	188	unsigned int ret = RTN_UNICAST;
abcab268	189	struct dn_fib_table *tb = dn_fib_get_table(RT_TABLE_LOCAL, 0);
1da177e4 LT	190
	191	res.r = NULL;
	192
	193	if (tb) {
bef55aeb	194	if (!tb->lookup(tb, &fld, &res)) {
1da177e4 LT	195	ret = res.type;
	196	dn_fib_res_put(&res);
	197	}
	198	}
	199	return ret;
	200	}
	201
a8731cbf	202	static int dn_fib_rule_fill(struct fib_rule rule, struct sk_buff skb,
04af8cf6	203	struct fib_rule_hdr *frh)
1da177e4	204	{
a8731cbf	205	struct dn_fib_rule r = (struct dn_fib_rule )rule;
1da177e4	206
a8731cbf SW	207	frh->dst_len = r->dst_len;
	208	frh->src_len = r->src_len;
	209	frh->tos = 0;
1da177e4	210
b21dddb9 DM	211	if ((r->dst_len &&
	212	nla_put_le16(skb, FRA_DST, r->dst)) \|\|
	213	(r->src_len &&
	214	nla_put_le16(skb, FRA_SRC, r->src)))
	215	goto nla_put_failure;
a8731cbf	216	return 0;
1da177e4	217
a8731cbf SW	218	nla_put_failure:
a8731cbf SW	219	return -ENOBUFS;
1da177e4 LT	220	}
1da177e4 LT	221
ae299fc0	222	static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops)
73417f61	223	{
4b19ca44	224	dn_rt_cache_flush(-1);
73417f61 TG	225	}
73417f61 TG	226
04a6f82c	227	static const struct fib_rules_ops __net_initconst dn_fib_rules_ops_template = {
25239cee	228	.family = AF_DECnet,
a8731cbf	229	.rule_size = sizeof(struct dn_fib_rule),
e1701c68	230	.addr_size = sizeof(u16),
a8731cbf SW	231	.action = dn_fib_rule_action,
	232	.match = dn_fib_rule_match,
	233	.configure = dn_fib_rule_configure,
	234	.compare = dn_fib_rule_compare,
	235	.fill = dn_fib_rule_fill,
73417f61	236	.flush_cache = dn_fib_rule_flush_cache,
a8731cbf SW	237	.nlgroup = RTNLGRP_DECnet_RULE,
a8731cbf SW	238	.policy = dn_fib_rule_policy,
a8731cbf	239	.owner = THIS_MODULE,
03592383	240	.fro_net = &init_net,
a8731cbf SW	241	};
a8731cbf SW	242
1da177e4 LT	243	void __init dn_fib_rules_init(void)
1da177e4 LT	244	{
e9c5158a EB	245	dn_fib_rules_ops =
	246	fib_rules_register(&dn_fib_rules_ops_template, &init_net);
	247	BUG_ON(IS_ERR(dn_fib_rules_ops));
	248	BUG_ON(fib_default_rule_add(dn_fib_rules_ops, 0x7fff,
2994c638	249	RT_TABLE_MAIN, 0));
1da177e4 LT	250	}
	251
	252	void __exit dn_fib_rules_cleanup(void)
	253	{
419df12f	254	rtnl_lock();
e9c5158a	255	fib_rules_unregister(dn_fib_rules_ops);
419df12f	256	rtnl_unlock();
e9c5158a	257	rcu_barrier();
1da177e4	258	}