aboutsummaryrefslogtreecommitdiffstats
path: root/net/sched/act_mpls.c
blob: bb9edac94e1be54471bbf7ab1489df2de3640f66 (plain) (blame)
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
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2019 Netronome Systems, Inc. */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mpls.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/tc_act/tc_mpls.h>
#include <net/mpls.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#include <net/tc_act/tc_mpls.h>

static unsigned int mpls_net_id;
static struct tc_action_ops act_mpls_ops;

#define ACT_MPLS_TTL_DEFAULT	255

static __be32 tcf_mpls_get_lse(struct mpls_shim_hdr *lse,
			       struct tcf_mpls_params *p, bool set_bos)
{
	u32 new_lse = 0;

	if (lse)
		new_lse = be32_to_cpu(lse->label_stack_entry);

	if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET) {
		new_lse &= ~MPLS_LS_LABEL_MASK;
		new_lse |= p->tcfm_label << MPLS_LS_LABEL_SHIFT;
	}
	if (p->tcfm_ttl) {
		new_lse &= ~MPLS_LS_TTL_MASK;
		new_lse |= p->tcfm_ttl << MPLS_LS_TTL_SHIFT;
	}
	if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET) {
		new_lse &= ~MPLS_LS_TC_MASK;
		new_lse |= p->tcfm_tc << MPLS_LS_TC_SHIFT;
	}
	if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET) {
		new_lse &= ~MPLS_LS_S_MASK;
		new_lse |= p->tcfm_bos << MPLS_LS_S_SHIFT;
	} else if (set_bos) {
		new_lse |= 1 << MPLS_LS_S_SHIFT;
	}

	return cpu_to_be32(new_lse);
}

static int tcf_mpls_act(struct sk_buff *skb, const struct tc_action *a,
			struct tcf_result *res)
{
	struct tcf_mpls *m = to_mpls(a);
	struct tcf_mpls_params *p;
	__be32 new_lse;
	int ret, mac_len;

	tcf_lastuse_update(&m->tcf_tm);
	bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);

	/* Ensure 'data' points at mac_header prior calling mpls manipulating
	 * functions.
	 */
	if (skb_at_tc_ingress(skb)) {
		skb_push_rcsum(skb, skb->mac_len);
		mac_len = skb->mac_len;
	} else {
		mac_len = skb_network_header(skb) - skb_mac_header(skb);
	}

	ret = READ_ONCE(m->tcf_action);

	p = rcu_dereference_bh(m->mpls_p);

	switch (p->tcfm_action) {
	case TCA_MPLS_ACT_POP:
		if (skb_mpls_pop(skb, p->tcfm_proto, mac_len))
			goto drop;
		break;
	case TCA_MPLS_ACT_PUSH:
		new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb->protocol));
		if (skb_mpls_push(skb, new_lse, p->tcfm_proto, mac_len))
			goto drop;
		break;
	case TCA_MPLS_ACT_MODIFY:
		new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false);
		if (skb_mpls_update_lse(skb, new_lse))
			goto drop;
		break;
	case TCA_MPLS_ACT_DEC_TTL:
		if (skb_mpls_dec_ttl(skb))
			goto drop;
		break;
	}

	if (skb_at_tc_ingress(skb))
		skb_pull_rcsum(skb, skb->mac_len);

	return ret;

drop:
	qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats));
	return TC_ACT_SHOT;
}

static int valid_label(const struct nlattr *attr,
		       struct netlink_ext_ack *extack)
{
	const u32 *label = nla_data(attr);

	if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) {
		NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range");
		return -EINVAL;
	}

	return 0;
}

static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = {
	[TCA_MPLS_UNSPEC]	= { .strict_start_type = TCA_MPLS_UNSPEC + 1 },
	[TCA_MPLS_PARMS]	= NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)),
	[TCA_MPLS_PROTO]	= { .type = NLA_U16 },
	[TCA_MPLS_LABEL]	= NLA_POLICY_VALIDATE_FN(NLA_U32, valid_label),
	[TCA_MPLS_TC]		= NLA_POLICY_RANGE(NLA_U8, 0, 7),
	[TCA_MPLS_TTL]		= NLA_POLICY_MIN(NLA_U8, 1),
	[TCA_MPLS_BOS]		= NLA_POLICY_RANGE(NLA_U8, 0, 1),
};

static int tcf_mpls_init(struct net *net, struct nlattr *nla,
			 struct nlattr *est, struct tc_action **a,
			 int ovr, int bind, bool rtnl_held,
			 struct tcf_proto *tp, struct netlink_ext_ack *extack)
{
	struct tc_action_net *tn = net_generic(net, mpls_net_id);
	struct nlattr *tb[TCA_MPLS_MAX + 1];
	struct tcf_chain *goto_ch = NULL;
	struct tcf_mpls_params *p;
	struct tc_mpls *parm;
	bool exists = false;
	struct tcf_mpls *m;
	int ret = 0, err;
	u8 mpls_ttl = 0;
	u32 index;

	if (!nla) {
		NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes");
		return -EINVAL;
	}

	err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack);
	if (err < 0)
		return err;

	if (!tb[TCA_MPLS_PARMS]) {
		NL_SET_ERR_MSG_MOD(extack, "No MPLS params");
		return -EINVAL;
	}
	parm = nla_data(tb[TCA_MPLS_PARMS]);
	index = parm->index;

	/* Verify parameters against action type. */
	switch (parm->m_action) {
	case TCA_MPLS_ACT_POP:
		if (!tb[TCA_MPLS_PROTO]) {
			NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop");
			return -EINVAL;
		}
		if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
			NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop");
			return -EINVAL;
		}
		if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] ||
		    tb[TCA_MPLS_BOS]) {
			NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop");
			return -EINVAL;
		}
		break;
	case TCA_MPLS_ACT_DEC_TTL:
		if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] ||
		    tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) {
			NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl");
			return -EINVAL;
		}
		break;
	case TCA_MPLS_ACT_PUSH:
		if (!tb[TCA_MPLS_LABEL]) {
			NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push");
			return -EINVAL;
		}
		if (tb[TCA_MPLS_PROTO] &&
		    !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
			NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push");
			return -EPROTONOSUPPORT;
		}
		/* Push needs a TTL - if not specified, set a default value. */
		if (!tb[TCA_MPLS_TTL]) {
#if IS_ENABLED(CONFIG_MPLS)
			mpls_ttl = net->mpls.default_ttl ?
				   net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT;
#else
			mpls_ttl = ACT_MPLS_TTL_DEFAULT;
#endif
		}
		break;
	case TCA_MPLS_ACT_MODIFY:
		if (tb[TCA_MPLS_PROTO]) {
			NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify");
			return -EINVAL;
		}
		break;
	default:
		NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action");
		return -EINVAL;
	}

	err = tcf_idr_check_alloc(tn, &index, a, bind);
	if (err < 0)
		return err;
	exists = err;
	if (exists && bind)
		return 0;

	if (!exists) {
		ret = tcf_idr_create(tn, index, est, a,
				     &act_mpls_ops, bind, true);
		if (ret) {
			tcf_idr_cleanup(tn, index);
			return ret;
		}

		ret = ACT_P_CREATED;
	} else if (!ovr) {
		tcf_idr_release(*a, bind);
		return -EEXIST;
	}

	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
	if (err < 0)
		goto release_idr;

	m = to_mpls(*a);

	p = kzalloc(sizeof(*p), GFP_KERNEL);
	if (!p) {
		err = -ENOMEM;
		goto put_chain;
	}

	p->tcfm_action = parm->m_action;
	p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) :
					     ACT_MPLS_LABEL_NOT_SET;
	p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) :
				       ACT_MPLS_TC_NOT_SET;
	p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) :
					 mpls_ttl;
	p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) :
					 ACT_MPLS_BOS_NOT_SET;
	p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) :
					     htons(ETH_P_MPLS_UC);

	spin_lock_bh(&m->tcf_lock);
	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
	p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
	spin_unlock_bh(&m->tcf_lock);

	if (goto_ch)
		tcf_chain_put_by_act(goto_ch);
	if (p)
		kfree_rcu(p, rcu);

	if (ret == ACT_P_CREATED)
		tcf_idr_insert(tn, *a);
	return ret;
put_chain:
	if (goto_ch)
		tcf_chain_put_by_act(goto_ch);
release_idr:
	tcf_idr_release(*a, bind);
	return err;
}

static void tcf_mpls_cleanup(struct tc_action *a)
{
	struct tcf_mpls *m = to_mpls(a);
	struct tcf_mpls_params *p;

	p = rcu_dereference_protected(m->mpls_p, 1);
	if (p)
		kfree_rcu(p, rcu);
}

static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a,
			 int bind, int ref)
{
	unsigned char *b = skb_tail_pointer(skb);
	struct tcf_mpls *m = to_mpls(a);
	struct tcf_mpls_params *p;
	struct tc_mpls opt = {
		.index    = m->tcf_index,
		.refcnt   = refcount_read(&m->tcf_refcnt) - ref,
		.bindcnt  = atomic_read(&m->tcf_bindcnt) - bind,
	};
	struct tcf_t t;

	spin_lock_bh(&m->tcf_lock);
	opt.action = m->tcf_action;
	p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock));
	opt.m_action = p->tcfm_action;

	if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt))
		goto nla_put_failure;

	if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET &&
	    nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label))
		goto nla_put_failure;

	if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET &&
	    nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc))
		goto nla_put_failure;

	if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl))
		goto nla_put_failure;

	if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET &&
	    nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos))
		goto nla_put_failure;

	if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto))
		goto nla_put_failure;

	tcf_tm_dump(&t, &m->tcf_tm);

	if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD))
		goto nla_put_failure;

	spin_unlock_bh(&m->tcf_lock);

	return skb->len;

nla_put_failure:
	spin_unlock_bh(&m->tcf_lock);
	nlmsg_trim(skb, b);
	return -EMSGSIZE;
}

static int tcf_mpls_walker(struct net *net, struct sk_buff *skb,
			   struct netlink_callback *cb, int type,
			   const struct tc_action_ops *ops,
			   struct netlink_ext_ack *extack)
{
	struct tc_action_net *tn = net_generic(net, mpls_net_id);

	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
}

static int tcf_mpls_search(struct net *net, struct tc_action **a, u32 index)
{
	struct tc_action_net *tn = net_generic(net, mpls_net_id);

	return tcf_idr_search(tn, a, index);
}

static struct tc_action_ops act_mpls_ops = {
	.kind		=	"mpls",
	.id		=	TCA_ID_MPLS,
	.owner		=	THIS_MODULE,
	.act		=	tcf_mpls_act,
	.dump		=	tcf_mpls_dump,
	.init		=	tcf_mpls_init,
	.cleanup	=	tcf_mpls_cleanup,
	.walk		=	tcf_mpls_walker,
	.lookup		=	tcf_mpls_search,
	.size		=	sizeof(struct tcf_mpls),
};

static __net_init int mpls_init_net(struct net *net)
{
	struct tc_action_net *tn = net_generic(net, mpls_net_id);

	return tc_action_net_init(net, tn, &act_mpls_ops);
}

static void __net_exit mpls_exit_net(struct list_head *net_list)
{
	tc_action_net_exit(net_list, mpls_net_id);
}

static struct pernet_operations mpls_net_ops = {
	.init = mpls_init_net,
	.exit_batch = mpls_exit_net,
	.id   = &mpls_net_id,
	.size = sizeof(struct tc_action_net),
};

static int __init mpls_init_module(void)
{
	return tcf_register_action(&act_mpls_ops, &mpls_net_ops);
}

static void __exit mpls_cleanup_module(void)
{
	tcf_unregister_action(&act_mpls_ops, &mpls_net_ops);
}

module_init(mpls_init_module);
module_exit(mpls_cleanup_module);

MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MPLS manipulation actions");