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  1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
  2/* Copyright (C) 2019 Netronome Systems, Inc. */
  3
  4#include <linux/if_arp.h>
  5#include <linux/init.h>
  6#include <linux/kernel.h>
  7#include <linux/module.h>
  8#include <linux/mpls.h>
  9#include <linux/rtnetlink.h>
 10#include <linux/skbuff.h>
 11#include <linux/tc_act/tc_mpls.h>
 12#include <net/mpls.h>
 13#include <net/netlink.h>
 14#include <net/pkt_sched.h>
 15#include <net/pkt_cls.h>
 16#include <net/tc_act/tc_mpls.h>
 17#include <net/tc_wrapper.h>
 18
 19static struct tc_action_ops act_mpls_ops;
 20
 21#define ACT_MPLS_TTL_DEFAULT	255
 22
 23static __be32 tcf_mpls_get_lse(struct mpls_shim_hdr *lse,
 24			       struct tcf_mpls_params *p, bool set_bos)
 25{
 26	u32 new_lse = 0;
 27
 28	if (lse)
 29		new_lse = be32_to_cpu(lse->label_stack_entry);
 30
 31	if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET) {
 32		new_lse &= ~MPLS_LS_LABEL_MASK;
 33		new_lse |= p->tcfm_label << MPLS_LS_LABEL_SHIFT;
 34	}
 35	if (p->tcfm_ttl) {
 36		new_lse &= ~MPLS_LS_TTL_MASK;
 37		new_lse |= p->tcfm_ttl << MPLS_LS_TTL_SHIFT;
 38	}
 39	if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET) {
 40		new_lse &= ~MPLS_LS_TC_MASK;
 41		new_lse |= p->tcfm_tc << MPLS_LS_TC_SHIFT;
 42	}
 43	if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET) {
 44		new_lse &= ~MPLS_LS_S_MASK;
 45		new_lse |= p->tcfm_bos << MPLS_LS_S_SHIFT;
 46	} else if (set_bos) {
 47		new_lse |= 1 << MPLS_LS_S_SHIFT;
 48	}
 49
 50	return cpu_to_be32(new_lse);
 51}
 52
 53TC_INDIRECT_SCOPE int tcf_mpls_act(struct sk_buff *skb,
 54				   const struct tc_action *a,
 55				   struct tcf_result *res)
 56{
 57	struct tcf_mpls *m = to_mpls(a);
 58	struct tcf_mpls_params *p;
 59	__be32 new_lse;
 60	int ret, mac_len;
 61
 62	tcf_lastuse_update(&m->tcf_tm);
 63	bstats_update(this_cpu_ptr(m->common.cpu_bstats), skb);
 64
 65	/* Ensure 'data' points at mac_header prior calling mpls manipulating
 66	 * functions.
 67	 */
 68	if (skb_at_tc_ingress(skb)) {
 69		skb_push_rcsum(skb, skb->mac_len);
 70		mac_len = skb->mac_len;
 71	} else {
 72		mac_len = skb_network_offset(skb);
 73	}
 74
 75	ret = READ_ONCE(m->tcf_action);
 76
 77	p = rcu_dereference_bh(m->mpls_p);
 78
 79	switch (p->tcfm_action) {
 80	case TCA_MPLS_ACT_POP:
 81		if (skb_mpls_pop(skb, p->tcfm_proto, mac_len,
 82				 skb->dev && skb->dev->type == ARPHRD_ETHER))
 83			goto drop;
 84		break;
 85	case TCA_MPLS_ACT_PUSH:
 86		new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb_protocol(skb, true)));
 87		if (skb_mpls_push(skb, new_lse, p->tcfm_proto, mac_len,
 88				  skb->dev && skb->dev->type == ARPHRD_ETHER))
 89			goto drop;
 90		break;
 91	case TCA_MPLS_ACT_MAC_PUSH:
 92		if (skb_vlan_tag_present(skb)) {
 93			if (__vlan_insert_inner_tag(skb, skb->vlan_proto,
 94						    skb_vlan_tag_get(skb),
 95						    ETH_HLEN) < 0)
 96				goto drop;
 97
 98			skb->protocol = skb->vlan_proto;
 99			__vlan_hwaccel_clear_tag(skb);
100		}
101
102		new_lse = tcf_mpls_get_lse(NULL, p, mac_len ||
103					   !eth_p_mpls(skb->protocol));
104
105		if (skb_mpls_push(skb, new_lse, p->tcfm_proto, 0, false))
106			goto drop;
107		break;
108	case TCA_MPLS_ACT_MODIFY:
109		if (!pskb_may_pull(skb,
110				   skb_network_offset(skb) + MPLS_HLEN))
111			goto drop;
112		new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false);
113		if (skb_mpls_update_lse(skb, new_lse))
114			goto drop;
115		break;
116	case TCA_MPLS_ACT_DEC_TTL:
117		if (skb_mpls_dec_ttl(skb))
118			goto drop;
119		break;
120	}
121
122	if (skb_at_tc_ingress(skb))
123		skb_pull_rcsum(skb, skb->mac_len);
124
125	return ret;
126
127drop:
128	qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats));
129	return TC_ACT_SHOT;
130}
131
132static int valid_label(const struct nlattr *attr,
133		       struct netlink_ext_ack *extack)
134{
135	const u32 *label = nla_data(attr);
136
137	if (nla_len(attr) != sizeof(*label)) {
138		NL_SET_ERR_MSG_MOD(extack, "Invalid MPLS label length");
139		return -EINVAL;
140	}
141
142	if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) {
143		NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range");
144		return -EINVAL;
145	}
146
147	return 0;
148}
149
150static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = {
151	[TCA_MPLS_PARMS]	= NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)),
152	[TCA_MPLS_PROTO]	= { .type = NLA_U16 },
153	[TCA_MPLS_LABEL]	= NLA_POLICY_VALIDATE_FN(NLA_BINARY,
154							 valid_label),
155	[TCA_MPLS_TC]		= NLA_POLICY_RANGE(NLA_U8, 0, 7),
156	[TCA_MPLS_TTL]		= NLA_POLICY_MIN(NLA_U8, 1),
157	[TCA_MPLS_BOS]		= NLA_POLICY_RANGE(NLA_U8, 0, 1),
158};
159
160static int tcf_mpls_init(struct net *net, struct nlattr *nla,
161			 struct nlattr *est, struct tc_action **a,
162			 struct tcf_proto *tp, u32 flags,
163			 struct netlink_ext_ack *extack)
164{
165	struct tc_action_net *tn = net_generic(net, act_mpls_ops.net_id);
166	bool bind = flags & TCA_ACT_FLAGS_BIND;
167	struct nlattr *tb[TCA_MPLS_MAX + 1];
168	struct tcf_chain *goto_ch = NULL;
169	struct tcf_mpls_params *p;
170	struct tc_mpls *parm;
171	bool exists = false;
172	struct tcf_mpls *m;
173	int ret = 0, err;
174	u8 mpls_ttl = 0;
175	u32 index;
176
177	if (!nla) {
178		NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes");
179		return -EINVAL;
180	}
181
182	err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack);
183	if (err < 0)
184		return err;
185
186	if (!tb[TCA_MPLS_PARMS]) {
187		NL_SET_ERR_MSG_MOD(extack, "No MPLS params");
188		return -EINVAL;
189	}
190	parm = nla_data(tb[TCA_MPLS_PARMS]);
191	index = parm->index;
192
193	err = tcf_idr_check_alloc(tn, &index, a, bind);
194	if (err < 0)
195		return err;
196	exists = err;
197	if (exists && bind)
198		return ACT_P_BOUND;
199
200	if (!exists) {
201		ret = tcf_idr_create(tn, index, est, a, &act_mpls_ops, bind,
202				     true, flags);
203		if (ret) {
204			tcf_idr_cleanup(tn, index);
205			return ret;
206		}
207
208		ret = ACT_P_CREATED;
209	} else if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
210		tcf_idr_release(*a, bind);
211		return -EEXIST;
212	}
213
214	/* Verify parameters against action type. */
215	switch (parm->m_action) {
216	case TCA_MPLS_ACT_POP:
217		if (!tb[TCA_MPLS_PROTO]) {
218			NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop");
219			err = -EINVAL;
220			goto release_idr;
221		}
222		if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
223			NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop");
224			err = -EINVAL;
225			goto release_idr;
226		}
227		if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] ||
228		    tb[TCA_MPLS_BOS]) {
229			NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop");
230			err = -EINVAL;
231			goto release_idr;
232		}
233		break;
234	case TCA_MPLS_ACT_DEC_TTL:
235		if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] ||
236		    tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) {
237			NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl");
238			err = -EINVAL;
239			goto release_idr;
240		}
241		break;
242	case TCA_MPLS_ACT_PUSH:
243	case TCA_MPLS_ACT_MAC_PUSH:
244		if (!tb[TCA_MPLS_LABEL]) {
245			NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push");
246			err = -EINVAL;
247			goto release_idr;
248		}
249		if (tb[TCA_MPLS_PROTO] &&
250		    !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
251			NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push");
252			err = -EPROTONOSUPPORT;
253			goto release_idr;
254		}
255		/* Push needs a TTL - if not specified, set a default value. */
256		if (!tb[TCA_MPLS_TTL]) {
257#if IS_ENABLED(CONFIG_MPLS)
258			mpls_ttl = net->mpls.default_ttl ?
259				   net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT;
260#else
261			mpls_ttl = ACT_MPLS_TTL_DEFAULT;
262#endif
263		}
264		break;
265	case TCA_MPLS_ACT_MODIFY:
266		if (tb[TCA_MPLS_PROTO]) {
267			NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify");
268			err = -EINVAL;
269			goto release_idr;
270		}
271		break;
272	default:
273		NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action");
274		err = -EINVAL;
275		goto release_idr;
276	}
277
278	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
279	if (err < 0)
280		goto release_idr;
281
282	m = to_mpls(*a);
283
284	p = kzalloc(sizeof(*p), GFP_KERNEL);
285	if (!p) {
286		err = -ENOMEM;
287		goto put_chain;
288	}
289
290	p->tcfm_action = parm->m_action;
291	p->tcfm_label = nla_get_u32_default(tb[TCA_MPLS_LABEL],
292					    ACT_MPLS_LABEL_NOT_SET);
293	p->tcfm_tc = nla_get_u8_default(tb[TCA_MPLS_TC], ACT_MPLS_TC_NOT_SET);
294	p->tcfm_ttl = nla_get_u8_default(tb[TCA_MPLS_TTL], mpls_ttl);
295	p->tcfm_bos = nla_get_u8_default(tb[TCA_MPLS_BOS],
296					 ACT_MPLS_BOS_NOT_SET);
297	p->tcfm_proto = nla_get_be16_default(tb[TCA_MPLS_PROTO],
298					     htons(ETH_P_MPLS_UC));
299
300	spin_lock_bh(&m->tcf_lock);
301	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
302	p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
303	spin_unlock_bh(&m->tcf_lock);
304
305	if (goto_ch)
306		tcf_chain_put_by_act(goto_ch);
307	if (p)
308		kfree_rcu(p, rcu);
309
310	return ret;
311put_chain:
312	if (goto_ch)
313		tcf_chain_put_by_act(goto_ch);
314release_idr:
315	tcf_idr_release(*a, bind);
316	return err;
317}
318
319static void tcf_mpls_cleanup(struct tc_action *a)
320{
321	struct tcf_mpls *m = to_mpls(a);
322	struct tcf_mpls_params *p;
323
324	p = rcu_dereference_protected(m->mpls_p, 1);
325	if (p)
326		kfree_rcu(p, rcu);
327}
328
329static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a,
330			 int bind, int ref)
331{
332	unsigned char *b = skb_tail_pointer(skb);
333	struct tcf_mpls *m = to_mpls(a);
334	struct tcf_mpls_params *p;
335	struct tc_mpls opt = {
336		.index    = m->tcf_index,
337		.refcnt   = refcount_read(&m->tcf_refcnt) - ref,
338		.bindcnt  = atomic_read(&m->tcf_bindcnt) - bind,
339	};
340	struct tcf_t t;
341
342	spin_lock_bh(&m->tcf_lock);
343	opt.action = m->tcf_action;
344	p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock));
345	opt.m_action = p->tcfm_action;
346
347	if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt))
348		goto nla_put_failure;
349
350	if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET &&
351	    nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label))
352		goto nla_put_failure;
353
354	if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET &&
355	    nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc))
356		goto nla_put_failure;
357
358	if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl))
359		goto nla_put_failure;
360
361	if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET &&
362	    nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos))
363		goto nla_put_failure;
364
365	if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto))
366		goto nla_put_failure;
367
368	tcf_tm_dump(&t, &m->tcf_tm);
369
370	if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD))
371		goto nla_put_failure;
372
373	spin_unlock_bh(&m->tcf_lock);
374
375	return skb->len;
376
377nla_put_failure:
378	spin_unlock_bh(&m->tcf_lock);
379	nlmsg_trim(skb, b);
380	return -EMSGSIZE;
381}
382
383static int tcf_mpls_offload_act_setup(struct tc_action *act, void *entry_data,
384				      u32 *index_inc, bool bind,
385				      struct netlink_ext_ack *extack)
386{
387	if (bind) {
388		struct flow_action_entry *entry = entry_data;
389
390		switch (tcf_mpls_action(act)) {
391		case TCA_MPLS_ACT_PUSH:
392			entry->id = FLOW_ACTION_MPLS_PUSH;
393			entry->mpls_push.proto = tcf_mpls_proto(act);
394			entry->mpls_push.label = tcf_mpls_label(act);
395			entry->mpls_push.tc = tcf_mpls_tc(act);
396			entry->mpls_push.bos = tcf_mpls_bos(act);
397			entry->mpls_push.ttl = tcf_mpls_ttl(act);
398			break;
399		case TCA_MPLS_ACT_POP:
400			entry->id = FLOW_ACTION_MPLS_POP;
401			entry->mpls_pop.proto = tcf_mpls_proto(act);
402			break;
403		case TCA_MPLS_ACT_MODIFY:
404			entry->id = FLOW_ACTION_MPLS_MANGLE;
405			entry->mpls_mangle.label = tcf_mpls_label(act);
406			entry->mpls_mangle.tc = tcf_mpls_tc(act);
407			entry->mpls_mangle.bos = tcf_mpls_bos(act);
408			entry->mpls_mangle.ttl = tcf_mpls_ttl(act);
409			break;
410		case TCA_MPLS_ACT_DEC_TTL:
411			NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"dec_ttl\" option is used");
412			return -EOPNOTSUPP;
413		case TCA_MPLS_ACT_MAC_PUSH:
414			NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"mac_push\" option is used");
415			return -EOPNOTSUPP;
416		default:
417			NL_SET_ERR_MSG_MOD(extack, "Unsupported MPLS mode offload");
418			return -EOPNOTSUPP;
419		}
420		*index_inc = 1;
421	} else {
422		struct flow_offload_action *fl_action = entry_data;
423
424		switch (tcf_mpls_action(act)) {
425		case TCA_MPLS_ACT_PUSH:
426			fl_action->id = FLOW_ACTION_MPLS_PUSH;
427			break;
428		case TCA_MPLS_ACT_POP:
429			fl_action->id = FLOW_ACTION_MPLS_POP;
430			break;
431		case TCA_MPLS_ACT_MODIFY:
432			fl_action->id = FLOW_ACTION_MPLS_MANGLE;
433			break;
434		default:
435			return -EOPNOTSUPP;
436		}
437	}
438
439	return 0;
440}
441
442static struct tc_action_ops act_mpls_ops = {
443	.kind		=	"mpls",
444	.id		=	TCA_ID_MPLS,
445	.owner		=	THIS_MODULE,
446	.act		=	tcf_mpls_act,
447	.dump		=	tcf_mpls_dump,
448	.init		=	tcf_mpls_init,
449	.cleanup	=	tcf_mpls_cleanup,
450	.offload_act_setup =	tcf_mpls_offload_act_setup,
451	.size		=	sizeof(struct tcf_mpls),
452};
453MODULE_ALIAS_NET_ACT("mpls");
454
455static __net_init int mpls_init_net(struct net *net)
456{
457	struct tc_action_net *tn = net_generic(net, act_mpls_ops.net_id);
458
459	return tc_action_net_init(net, tn, &act_mpls_ops);
460}
461
462static void __net_exit mpls_exit_net(struct list_head *net_list)
463{
464	tc_action_net_exit(net_list, act_mpls_ops.net_id);
465}
466
467static struct pernet_operations mpls_net_ops = {
468	.init = mpls_init_net,
469	.exit_batch = mpls_exit_net,
470	.id   = &act_mpls_ops.net_id,
471	.size = sizeof(struct tc_action_net),
472};
473
474static int __init mpls_init_module(void)
475{
476	return tcf_register_action(&act_mpls_ops, &mpls_net_ops);
477}
478
479static void __exit mpls_cleanup_module(void)
480{
481	tcf_unregister_action(&act_mpls_ops, &mpls_net_ops);
482}
483
484module_init(mpls_init_module);
485module_exit(mpls_cleanup_module);
486
487MODULE_SOFTDEP("post: mpls_gso");
488MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>");
489MODULE_LICENSE("GPL");
490MODULE_DESCRIPTION("MPLS manipulation actions");