summaryrefslogtreecommitdiff
path: root/net/l3mdev/l3mdev.c
blob: ca10916340b098fb1f7e8c577bcca1eec4f4814d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * net/l3mdev/l3mdev.c - L3 master device implementation
 * Copyright (c) 2015 Cumulus Networks
 * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
 */

#include <linux/netdevice.h>
#include <net/fib_rules.h>
#include <net/l3mdev.h>

static DEFINE_SPINLOCK(l3mdev_lock);

struct l3mdev_handler {
	lookup_by_table_id_t dev_lookup;
};

static struct l3mdev_handler l3mdev_handlers[L3MDEV_TYPE_MAX + 1];

static int l3mdev_check_type(enum l3mdev_type l3type)
{
	if (l3type <= L3MDEV_TYPE_UNSPEC || l3type > L3MDEV_TYPE_MAX)
		return -EINVAL;

	return 0;
}

int l3mdev_table_lookup_register(enum l3mdev_type l3type,
				 lookup_by_table_id_t fn)
{
	struct l3mdev_handler *hdlr;
	int res;

	res = l3mdev_check_type(l3type);
	if (res)
		return res;

	hdlr = &l3mdev_handlers[l3type];

	spin_lock(&l3mdev_lock);

	if (hdlr->dev_lookup) {
		res = -EBUSY;
		goto unlock;
	}

	hdlr->dev_lookup = fn;
	res = 0;

unlock:
	spin_unlock(&l3mdev_lock);

	return res;
}
EXPORT_SYMBOL_GPL(l3mdev_table_lookup_register);

void l3mdev_table_lookup_unregister(enum l3mdev_type l3type,
				    lookup_by_table_id_t fn)
{
	struct l3mdev_handler *hdlr;

	if (l3mdev_check_type(l3type))
		return;

	hdlr = &l3mdev_handlers[l3type];

	spin_lock(&l3mdev_lock);

	if (hdlr->dev_lookup == fn)
		hdlr->dev_lookup = NULL;

	spin_unlock(&l3mdev_lock);
}
EXPORT_SYMBOL_GPL(l3mdev_table_lookup_unregister);

int l3mdev_ifindex_lookup_by_table_id(enum l3mdev_type l3type,
				      struct net *net, u32 table_id)
{
	lookup_by_table_id_t lookup;
	struct l3mdev_handler *hdlr;
	int ifindex = -EINVAL;
	int res;

	res = l3mdev_check_type(l3type);
	if (res)
		return res;

	hdlr = &l3mdev_handlers[l3type];

	spin_lock(&l3mdev_lock);

	lookup = hdlr->dev_lookup;
	if (!lookup)
		goto unlock;

	ifindex = lookup(net, table_id);

unlock:
	spin_unlock(&l3mdev_lock);

	return ifindex;
}
EXPORT_SYMBOL_GPL(l3mdev_ifindex_lookup_by_table_id);

/**
 *	l3mdev_master_ifindex_rcu - get index of L3 master device
 *	@dev: targeted interface
 */

int l3mdev_master_ifindex_rcu(const struct net_device *dev)
{
	int ifindex = 0;

	if (!dev)
		return 0;

	if (netif_is_l3_master(dev)) {
		ifindex = dev->ifindex;
	} else if (netif_is_l3_slave(dev)) {
		struct net_device *master;
		struct net_device *_dev = (struct net_device *)dev;

		/* netdev_master_upper_dev_get_rcu calls
		 * list_first_or_null_rcu to walk the upper dev list.
		 * list_first_or_null_rcu does not handle a const arg. We aren't
		 * making changes, just want the master device from that list so
		 * typecast to remove the const
		 */
		master = netdev_master_upper_dev_get_rcu(_dev);
		if (master)
			ifindex = master->ifindex;
	}

	return ifindex;
}
EXPORT_SYMBOL_GPL(l3mdev_master_ifindex_rcu);

/**
 *	l3mdev_master_upper_ifindex_by_index_rcu - get index of upper l3 master
 *					       device
 *	@net: network namespace for device index lookup
 *	@ifindex: targeted interface
 */
int l3mdev_master_upper_ifindex_by_index_rcu(struct net *net, int ifindex)
{
	struct net_device *dev;

	dev = dev_get_by_index_rcu(net, ifindex);
	while (dev && !netif_is_l3_master(dev))
		dev = netdev_master_upper_dev_get_rcu(dev);

	return dev ? dev->ifindex : 0;
}
EXPORT_SYMBOL_GPL(l3mdev_master_upper_ifindex_by_index_rcu);

/**
 *	l3mdev_fib_table_rcu - get FIB table id associated with an L3
 *                             master interface
 *	@dev: targeted interface
 */

u32 l3mdev_fib_table_rcu(const struct net_device *dev)
{
	u32 tb_id = 0;

	if (!dev)
		return 0;

	if (netif_is_l3_master(dev)) {
		if (dev->l3mdev_ops->l3mdev_fib_table)
			tb_id = dev->l3mdev_ops->l3mdev_fib_table(dev);
	} else if (netif_is_l3_slave(dev)) {
		/* Users of netdev_master_upper_dev_get_rcu need non-const,
		 * but current inet_*type functions take a const
		 */
		struct net_device *_dev = (struct net_device *) dev;
		const struct net_device *master;

		master = netdev_master_upper_dev_get_rcu(_dev);
		if (master &&
		    master->l3mdev_ops->l3mdev_fib_table)
			tb_id = master->l3mdev_ops->l3mdev_fib_table(master);
	}

	return tb_id;
}
EXPORT_SYMBOL_GPL(l3mdev_fib_table_rcu);

u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
{
	struct net_device *dev;
	u32 tb_id = 0;

	if (!ifindex)
		return 0;

	rcu_read_lock();

	dev = dev_get_by_index_rcu(net, ifindex);
	if (dev)
		tb_id = l3mdev_fib_table_rcu(dev);

	rcu_read_unlock();

	return tb_id;
}
EXPORT_SYMBOL_GPL(l3mdev_fib_table_by_index);

/**
 *	l3mdev_link_scope_lookup - IPv6 route lookup based on flow for link
 *			     local and multicast addresses
 *	@net: network namespace for device index lookup
 *	@fl6: IPv6 flow struct for lookup
 *	This function does not hold refcnt on the returned dst.
 *	Caller must hold rcu_read_lock().
 */

struct dst_entry *l3mdev_link_scope_lookup(struct net *net,
					   struct flowi6 *fl6)
{
	struct dst_entry *dst = NULL;
	struct net_device *dev;

	WARN_ON_ONCE(!rcu_read_lock_held());
	if (fl6->flowi6_oif) {
		dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
		if (dev && netif_is_l3_slave(dev))
			dev = netdev_master_upper_dev_get_rcu(dev);

		if (dev && netif_is_l3_master(dev) &&
		    dev->l3mdev_ops->l3mdev_link_scope_lookup)
			dst = dev->l3mdev_ops->l3mdev_link_scope_lookup(dev, fl6);
	}

	return dst;
}
EXPORT_SYMBOL_GPL(l3mdev_link_scope_lookup);

/**
 *	l3mdev_fib_rule_match - Determine if flowi references an
 *				L3 master device
 *	@net: network namespace for device index lookup
 *	@fl:  flow struct
 *	@arg: store the table the rule matched with here
 */

int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
			  struct fib_lookup_arg *arg)
{
	struct net_device *dev;
	int rc = 0;

	/* update flow ensures flowi_l3mdev is set when relevant */
	if (!fl->flowi_l3mdev)
		return 0;

	rcu_read_lock();

	dev = dev_get_by_index_rcu(net, fl->flowi_l3mdev);
	if (dev && netif_is_l3_master(dev) &&
	    dev->l3mdev_ops->l3mdev_fib_table) {
		arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev);
		rc = 1;
	}

	rcu_read_unlock();

	return rc;
}

void l3mdev_update_flow(struct net *net, struct flowi *fl)
{
	struct net_device *dev;

	rcu_read_lock();

	if (fl->flowi_oif) {
		dev = dev_get_by_index_rcu(net, fl->flowi_oif);
		if (dev) {
			if (!fl->flowi_l3mdev)
				fl->flowi_l3mdev = l3mdev_master_ifindex_rcu(dev);

			/* oif set to L3mdev directs lookup to its table;
			 * reset to avoid oif match in fib_lookup
			 */
			if (netif_is_l3_master(dev))
				fl->flowi_oif = 0;
			goto out;
		}
	}

	if (fl->flowi_iif > LOOPBACK_IFINDEX && !fl->flowi_l3mdev) {
		dev = dev_get_by_index_rcu(net, fl->flowi_iif);
		if (dev)
			fl->flowi_l3mdev = l3mdev_master_ifindex_rcu(dev);
	}

out:
	rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(l3mdev_update_flow);