xref: /linux/include/net/sch_generic.h (revision ca64d84e93762f4e587e040a44ad9f6089afc777)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __NET_SCHED_GENERIC_H
3 #define __NET_SCHED_GENERIC_H
4 
5 #include <linux/netdevice.h>
6 #include <linux/types.h>
7 #include <linux/rcupdate.h>
8 #include <linux/pkt_sched.h>
9 #include <linux/pkt_cls.h>
10 #include <linux/percpu.h>
11 #include <linux/dynamic_queue_limits.h>
12 #include <linux/list.h>
13 #include <linux/refcount.h>
14 #include <linux/workqueue.h>
15 #include <linux/mutex.h>
16 #include <linux/rwsem.h>
17 #include <linux/atomic.h>
18 #include <linux/hashtable.h>
19 #include <net/gen_stats.h>
20 #include <net/rtnetlink.h>
21 #include <net/flow_offload.h>
22 
23 struct Qdisc_ops;
24 struct qdisc_walker;
25 struct tcf_walker;
26 struct module;
27 struct bpf_flow_keys;
28 
29 struct qdisc_rate_table {
30 	struct tc_ratespec rate;
31 	u32		data[256];
32 	struct qdisc_rate_table *next;
33 	int		refcnt;
34 };
35 
36 enum qdisc_state_t {
37 	__QDISC_STATE_SCHED,
38 	__QDISC_STATE_DEACTIVATED,
39 };
40 
41 struct qdisc_size_table {
42 	struct rcu_head		rcu;
43 	struct list_head	list;
44 	struct tc_sizespec	szopts;
45 	int			refcnt;
46 	u16			data[];
47 };
48 
49 /* similar to sk_buff_head, but skb->prev pointer is undefined. */
50 struct qdisc_skb_head {
51 	struct sk_buff	*head;
52 	struct sk_buff	*tail;
53 	__u32		qlen;
54 	spinlock_t	lock;
55 };
56 
57 struct Qdisc {
58 	int 			(*enqueue)(struct sk_buff *skb,
59 					   struct Qdisc *sch,
60 					   struct sk_buff **to_free);
61 	struct sk_buff *	(*dequeue)(struct Qdisc *sch);
62 	unsigned int		flags;
63 #define TCQ_F_BUILTIN		1
64 #define TCQ_F_INGRESS		2
65 #define TCQ_F_CAN_BYPASS	4
66 #define TCQ_F_MQROOT		8
67 #define TCQ_F_ONETXQUEUE	0x10 /* dequeue_skb() can assume all skbs are for
68 				      * q->dev_queue : It can test
69 				      * netif_xmit_frozen_or_stopped() before
70 				      * dequeueing next packet.
71 				      * Its true for MQ/MQPRIO slaves, or non
72 				      * multiqueue device.
73 				      */
74 #define TCQ_F_WARN_NONWC	(1 << 16)
75 #define TCQ_F_CPUSTATS		0x20 /* run using percpu statistics */
76 #define TCQ_F_NOPARENT		0x40 /* root of its hierarchy :
77 				      * qdisc_tree_decrease_qlen() should stop.
78 				      */
79 #define TCQ_F_INVISIBLE		0x80 /* invisible by default in dump */
80 #define TCQ_F_NOLOCK		0x100 /* qdisc does not require locking */
81 #define TCQ_F_OFFLOADED		0x200 /* qdisc is offloaded to HW */
82 	u32			limit;
83 	const struct Qdisc_ops	*ops;
84 	struct qdisc_size_table	__rcu *stab;
85 	struct hlist_node       hash;
86 	u32			handle;
87 	u32			parent;
88 
89 	struct netdev_queue	*dev_queue;
90 
91 	struct net_rate_estimator __rcu *rate_est;
92 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
93 	struct gnet_stats_queue	__percpu *cpu_qstats;
94 	int			padded;
95 	refcount_t		refcnt;
96 
97 	/*
98 	 * For performance sake on SMP, we put highly modified fields at the end
99 	 */
100 	struct sk_buff_head	gso_skb ____cacheline_aligned_in_smp;
101 	struct qdisc_skb_head	q;
102 	struct gnet_stats_basic_packed bstats;
103 	seqcount_t		running;
104 	struct gnet_stats_queue	qstats;
105 	unsigned long		state;
106 	struct Qdisc            *next_sched;
107 	struct sk_buff_head	skb_bad_txq;
108 
109 	spinlock_t		busylock ____cacheline_aligned_in_smp;
110 	spinlock_t		seqlock;
111 
112 	/* for NOLOCK qdisc, true if there are no enqueued skbs */
113 	bool			empty;
114 	struct rcu_head		rcu;
115 };
116 
117 static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
118 {
119 	if (qdisc->flags & TCQ_F_BUILTIN)
120 		return;
121 	refcount_inc(&qdisc->refcnt);
122 }
123 
124 /* Intended to be used by unlocked users, when concurrent qdisc release is
125  * possible.
126  */
127 
128 static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc)
129 {
130 	if (qdisc->flags & TCQ_F_BUILTIN)
131 		return qdisc;
132 	if (refcount_inc_not_zero(&qdisc->refcnt))
133 		return qdisc;
134 	return NULL;
135 }
136 
137 static inline bool qdisc_is_running(struct Qdisc *qdisc)
138 {
139 	if (qdisc->flags & TCQ_F_NOLOCK)
140 		return spin_is_locked(&qdisc->seqlock);
141 	return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
142 }
143 
144 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
145 {
146 	return q->flags & TCQ_F_CPUSTATS;
147 }
148 
149 static inline bool qdisc_is_empty(const struct Qdisc *qdisc)
150 {
151 	if (qdisc_is_percpu_stats(qdisc))
152 		return READ_ONCE(qdisc->empty);
153 	return !READ_ONCE(qdisc->q.qlen);
154 }
155 
156 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
157 {
158 	if (qdisc->flags & TCQ_F_NOLOCK) {
159 		if (!spin_trylock(&qdisc->seqlock))
160 			return false;
161 		WRITE_ONCE(qdisc->empty, false);
162 	} else if (qdisc_is_running(qdisc)) {
163 		return false;
164 	}
165 	/* Variant of write_seqcount_begin() telling lockdep a trylock
166 	 * was attempted.
167 	 */
168 	raw_write_seqcount_begin(&qdisc->running);
169 	seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
170 	return true;
171 }
172 
173 static inline void qdisc_run_end(struct Qdisc *qdisc)
174 {
175 	write_seqcount_end(&qdisc->running);
176 	if (qdisc->flags & TCQ_F_NOLOCK)
177 		spin_unlock(&qdisc->seqlock);
178 }
179 
180 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
181 {
182 	return qdisc->flags & TCQ_F_ONETXQUEUE;
183 }
184 
185 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
186 {
187 #ifdef CONFIG_BQL
188 	/* Non-BQL migrated drivers will return 0, too. */
189 	return dql_avail(&txq->dql);
190 #else
191 	return 0;
192 #endif
193 }
194 
195 struct Qdisc_class_ops {
196 	unsigned int		flags;
197 	/* Child qdisc manipulation */
198 	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);
199 	int			(*graft)(struct Qdisc *, unsigned long cl,
200 					struct Qdisc *, struct Qdisc **,
201 					struct netlink_ext_ack *extack);
202 	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);
203 	void			(*qlen_notify)(struct Qdisc *, unsigned long);
204 
205 	/* Class manipulation routines */
206 	unsigned long		(*find)(struct Qdisc *, u32 classid);
207 	int			(*change)(struct Qdisc *, u32, u32,
208 					struct nlattr **, unsigned long *,
209 					struct netlink_ext_ack *);
210 	int			(*delete)(struct Qdisc *, unsigned long);
211 	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);
212 
213 	/* Filter manipulation */
214 	struct tcf_block *	(*tcf_block)(struct Qdisc *sch,
215 					     unsigned long arg,
216 					     struct netlink_ext_ack *extack);
217 	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
218 					u32 classid);
219 	void			(*unbind_tcf)(struct Qdisc *, unsigned long);
220 
221 	/* rtnetlink specific */
222 	int			(*dump)(struct Qdisc *, unsigned long,
223 					struct sk_buff *skb, struct tcmsg*);
224 	int			(*dump_stats)(struct Qdisc *, unsigned long,
225 					struct gnet_dump *);
226 };
227 
228 /* Qdisc_class_ops flag values */
229 
230 /* Implements API that doesn't require rtnl lock */
231 enum qdisc_class_ops_flags {
232 	QDISC_CLASS_OPS_DOIT_UNLOCKED = 1,
233 };
234 
235 struct Qdisc_ops {
236 	struct Qdisc_ops	*next;
237 	const struct Qdisc_class_ops	*cl_ops;
238 	char			id[IFNAMSIZ];
239 	int			priv_size;
240 	unsigned int		static_flags;
241 
242 	int 			(*enqueue)(struct sk_buff *skb,
243 					   struct Qdisc *sch,
244 					   struct sk_buff **to_free);
245 	struct sk_buff *	(*dequeue)(struct Qdisc *);
246 	struct sk_buff *	(*peek)(struct Qdisc *);
247 
248 	int			(*init)(struct Qdisc *sch, struct nlattr *arg,
249 					struct netlink_ext_ack *extack);
250 	void			(*reset)(struct Qdisc *);
251 	void			(*destroy)(struct Qdisc *);
252 	int			(*change)(struct Qdisc *sch,
253 					  struct nlattr *arg,
254 					  struct netlink_ext_ack *extack);
255 	void			(*attach)(struct Qdisc *sch);
256 	int			(*change_tx_queue_len)(struct Qdisc *, unsigned int);
257 
258 	int			(*dump)(struct Qdisc *, struct sk_buff *);
259 	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);
260 
261 	void			(*ingress_block_set)(struct Qdisc *sch,
262 						     u32 block_index);
263 	void			(*egress_block_set)(struct Qdisc *sch,
264 						    u32 block_index);
265 	u32			(*ingress_block_get)(struct Qdisc *sch);
266 	u32			(*egress_block_get)(struct Qdisc *sch);
267 
268 	struct module		*owner;
269 };
270 
271 
272 struct tcf_result {
273 	union {
274 		struct {
275 			unsigned long	class;
276 			u32		classid;
277 		};
278 		const struct tcf_proto *goto_tp;
279 
280 		/* used in the skb_tc_reinsert function */
281 		struct {
282 			bool		ingress;
283 			struct gnet_stats_queue *qstats;
284 		};
285 	};
286 };
287 
288 struct tcf_chain;
289 
290 struct tcf_proto_ops {
291 	struct list_head	head;
292 	char			kind[IFNAMSIZ];
293 
294 	int			(*classify)(struct sk_buff *,
295 					    const struct tcf_proto *,
296 					    struct tcf_result *);
297 	int			(*init)(struct tcf_proto*);
298 	void			(*destroy)(struct tcf_proto *tp, bool rtnl_held,
299 					   struct netlink_ext_ack *extack);
300 
301 	void*			(*get)(struct tcf_proto*, u32 handle);
302 	void			(*put)(struct tcf_proto *tp, void *f);
303 	int			(*change)(struct net *net, struct sk_buff *,
304 					struct tcf_proto*, unsigned long,
305 					u32 handle, struct nlattr **,
306 					void **, bool, bool,
307 					struct netlink_ext_ack *);
308 	int			(*delete)(struct tcf_proto *tp, void *arg,
309 					  bool *last, bool rtnl_held,
310 					  struct netlink_ext_ack *);
311 	bool			(*delete_empty)(struct tcf_proto *tp);
312 	void			(*walk)(struct tcf_proto *tp,
313 					struct tcf_walker *arg, bool rtnl_held);
314 	int			(*reoffload)(struct tcf_proto *tp, bool add,
315 					     flow_setup_cb_t *cb, void *cb_priv,
316 					     struct netlink_ext_ack *extack);
317 	void			(*hw_add)(struct tcf_proto *tp,
318 					  void *type_data);
319 	void			(*hw_del)(struct tcf_proto *tp,
320 					  void *type_data);
321 	void			(*bind_class)(void *, u32, unsigned long,
322 					      void *, unsigned long);
323 	void *			(*tmplt_create)(struct net *net,
324 						struct tcf_chain *chain,
325 						struct nlattr **tca,
326 						struct netlink_ext_ack *extack);
327 	void			(*tmplt_destroy)(void *tmplt_priv);
328 
329 	/* rtnetlink specific */
330 	int			(*dump)(struct net*, struct tcf_proto*, void *,
331 					struct sk_buff *skb, struct tcmsg*,
332 					bool);
333 	int			(*tmplt_dump)(struct sk_buff *skb,
334 					      struct net *net,
335 					      void *tmplt_priv);
336 
337 	struct module		*owner;
338 	int			flags;
339 };
340 
341 /* Classifiers setting TCF_PROTO_OPS_DOIT_UNLOCKED in tcf_proto_ops->flags
342  * are expected to implement tcf_proto_ops->delete_empty(), otherwise race
343  * conditions can occur when filters are inserted/deleted simultaneously.
344  */
345 enum tcf_proto_ops_flags {
346 	TCF_PROTO_OPS_DOIT_UNLOCKED = 1,
347 };
348 
349 struct tcf_proto {
350 	/* Fast access part */
351 	struct tcf_proto __rcu	*next;
352 	void __rcu		*root;
353 
354 	/* called under RCU BH lock*/
355 	int			(*classify)(struct sk_buff *,
356 					    const struct tcf_proto *,
357 					    struct tcf_result *);
358 	__be16			protocol;
359 
360 	/* All the rest */
361 	u32			prio;
362 	void			*data;
363 	const struct tcf_proto_ops	*ops;
364 	struct tcf_chain	*chain;
365 	/* Lock protects tcf_proto shared state and can be used by unlocked
366 	 * classifiers to protect their private data.
367 	 */
368 	spinlock_t		lock;
369 	bool			deleting;
370 	refcount_t		refcnt;
371 	struct rcu_head		rcu;
372 	struct hlist_node	destroy_ht_node;
373 };
374 
375 struct qdisc_skb_cb {
376 	struct {
377 		unsigned int		pkt_len;
378 		u16			slave_dev_queue_mapping;
379 		u16			tc_classid;
380 	};
381 #define QDISC_CB_PRIV_LEN 20
382 	unsigned char		data[QDISC_CB_PRIV_LEN];
383 };
384 
385 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
386 
387 struct tcf_chain {
388 	/* Protects filter_chain. */
389 	struct mutex filter_chain_lock;
390 	struct tcf_proto __rcu *filter_chain;
391 	struct list_head list;
392 	struct tcf_block *block;
393 	u32 index; /* chain index */
394 	unsigned int refcnt;
395 	unsigned int action_refcnt;
396 	bool explicitly_created;
397 	bool flushing;
398 	const struct tcf_proto_ops *tmplt_ops;
399 	void *tmplt_priv;
400 	struct rcu_head rcu;
401 };
402 
403 struct tcf_block {
404 	/* Lock protects tcf_block and lifetime-management data of chains
405 	 * attached to the block (refcnt, action_refcnt, explicitly_created).
406 	 */
407 	struct mutex lock;
408 	struct list_head chain_list;
409 	u32 index; /* block index for shared blocks */
410 	refcount_t refcnt;
411 	struct net *net;
412 	struct Qdisc *q;
413 	struct rw_semaphore cb_lock; /* protects cb_list and offload counters */
414 	struct flow_block flow_block;
415 	struct list_head owner_list;
416 	bool keep_dst;
417 	atomic_t offloadcnt; /* Number of oddloaded filters */
418 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
419 	unsigned int lockeddevcnt; /* Number of devs that require rtnl lock. */
420 	struct {
421 		struct tcf_chain *chain;
422 		struct list_head filter_chain_list;
423 	} chain0;
424 	struct rcu_head rcu;
425 	DECLARE_HASHTABLE(proto_destroy_ht, 7);
426 	struct mutex proto_destroy_lock; /* Lock for proto_destroy hashtable. */
427 };
428 
429 #ifdef CONFIG_PROVE_LOCKING
430 static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
431 {
432 	return lockdep_is_held(&chain->filter_chain_lock);
433 }
434 
435 static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
436 {
437 	return lockdep_is_held(&tp->lock);
438 }
439 #else
440 static inline bool lockdep_tcf_chain_is_locked(struct tcf_block *chain)
441 {
442 	return true;
443 }
444 
445 static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
446 {
447 	return true;
448 }
449 #endif /* #ifdef CONFIG_PROVE_LOCKING */
450 
451 #define tcf_chain_dereference(p, chain)					\
452 	rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
453 
454 #define tcf_proto_dereference(p, tp)					\
455 	rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))
456 
457 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
458 {
459 	struct qdisc_skb_cb *qcb;
460 
461 	BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz);
462 	BUILD_BUG_ON(sizeof(qcb->data) < sz);
463 }
464 
465 static inline int qdisc_qlen_cpu(const struct Qdisc *q)
466 {
467 	return this_cpu_ptr(q->cpu_qstats)->qlen;
468 }
469 
470 static inline int qdisc_qlen(const struct Qdisc *q)
471 {
472 	return q->q.qlen;
473 }
474 
475 static inline int qdisc_qlen_sum(const struct Qdisc *q)
476 {
477 	__u32 qlen = q->qstats.qlen;
478 	int i;
479 
480 	if (qdisc_is_percpu_stats(q)) {
481 		for_each_possible_cpu(i)
482 			qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
483 	} else {
484 		qlen += q->q.qlen;
485 	}
486 
487 	return qlen;
488 }
489 
490 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
491 {
492 	return (struct qdisc_skb_cb *)skb->cb;
493 }
494 
495 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
496 {
497 	return &qdisc->q.lock;
498 }
499 
500 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
501 {
502 	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
503 
504 	return q;
505 }
506 
507 static inline struct Qdisc *qdisc_root_bh(const struct Qdisc *qdisc)
508 {
509 	return rcu_dereference_bh(qdisc->dev_queue->qdisc);
510 }
511 
512 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
513 {
514 	return qdisc->dev_queue->qdisc_sleeping;
515 }
516 
517 /* The qdisc root lock is a mechanism by which to top level
518  * of a qdisc tree can be locked from any qdisc node in the
519  * forest.  This allows changing the configuration of some
520  * aspect of the qdisc tree while blocking out asynchronous
521  * qdisc access in the packet processing paths.
522  *
523  * It is only legal to do this when the root will not change
524  * on us.  Otherwise we'll potentially lock the wrong qdisc
525  * root.  This is enforced by holding the RTNL semaphore, which
526  * all users of this lock accessor must do.
527  */
528 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
529 {
530 	struct Qdisc *root = qdisc_root(qdisc);
531 
532 	ASSERT_RTNL();
533 	return qdisc_lock(root);
534 }
535 
536 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
537 {
538 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
539 
540 	ASSERT_RTNL();
541 	return qdisc_lock(root);
542 }
543 
544 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
545 {
546 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
547 
548 	ASSERT_RTNL();
549 	return &root->running;
550 }
551 
552 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
553 {
554 	return qdisc->dev_queue->dev;
555 }
556 
557 static inline void sch_tree_lock(const struct Qdisc *q)
558 {
559 	spin_lock_bh(qdisc_root_sleeping_lock(q));
560 }
561 
562 static inline void sch_tree_unlock(const struct Qdisc *q)
563 {
564 	spin_unlock_bh(qdisc_root_sleeping_lock(q));
565 }
566 
567 extern struct Qdisc noop_qdisc;
568 extern struct Qdisc_ops noop_qdisc_ops;
569 extern struct Qdisc_ops pfifo_fast_ops;
570 extern struct Qdisc_ops mq_qdisc_ops;
571 extern struct Qdisc_ops noqueue_qdisc_ops;
572 extern const struct Qdisc_ops *default_qdisc_ops;
573 static inline const struct Qdisc_ops *
574 get_default_qdisc_ops(const struct net_device *dev, int ntx)
575 {
576 	return ntx < dev->real_num_tx_queues ?
577 			default_qdisc_ops : &pfifo_fast_ops;
578 }
579 
580 struct Qdisc_class_common {
581 	u32			classid;
582 	struct hlist_node	hnode;
583 };
584 
585 struct Qdisc_class_hash {
586 	struct hlist_head	*hash;
587 	unsigned int		hashsize;
588 	unsigned int		hashmask;
589 	unsigned int		hashelems;
590 };
591 
592 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
593 {
594 	id ^= id >> 8;
595 	id ^= id >> 4;
596 	return id & mask;
597 }
598 
599 static inline struct Qdisc_class_common *
600 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
601 {
602 	struct Qdisc_class_common *cl;
603 	unsigned int h;
604 
605 	if (!id)
606 		return NULL;
607 
608 	h = qdisc_class_hash(id, hash->hashmask);
609 	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
610 		if (cl->classid == id)
611 			return cl;
612 	}
613 	return NULL;
614 }
615 
616 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
617 {
618 	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
619 
620 	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
621 }
622 
623 int qdisc_class_hash_init(struct Qdisc_class_hash *);
624 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
625 			     struct Qdisc_class_common *);
626 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
627 			     struct Qdisc_class_common *);
628 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
629 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
630 
631 int dev_qdisc_change_tx_queue_len(struct net_device *dev);
632 void dev_init_scheduler(struct net_device *dev);
633 void dev_shutdown(struct net_device *dev);
634 void dev_activate(struct net_device *dev);
635 void dev_deactivate(struct net_device *dev);
636 void dev_deactivate_many(struct list_head *head);
637 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
638 			      struct Qdisc *qdisc);
639 void qdisc_reset(struct Qdisc *qdisc);
640 void qdisc_put(struct Qdisc *qdisc);
641 void qdisc_put_unlocked(struct Qdisc *qdisc);
642 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, int n, int len);
643 #ifdef CONFIG_NET_SCHED
644 int qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
645 			      void *type_data);
646 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
647 				struct Qdisc *new, struct Qdisc *old,
648 				enum tc_setup_type type, void *type_data,
649 				struct netlink_ext_ack *extack);
650 #else
651 static inline int
652 qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
653 			  void *type_data)
654 {
655 	q->flags &= ~TCQ_F_OFFLOADED;
656 	return 0;
657 }
658 
659 static inline void
660 qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
661 			   struct Qdisc *new, struct Qdisc *old,
662 			   enum tc_setup_type type, void *type_data,
663 			   struct netlink_ext_ack *extack)
664 {
665 }
666 #endif
667 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
668 			  const struct Qdisc_ops *ops,
669 			  struct netlink_ext_ack *extack);
670 void qdisc_free(struct Qdisc *qdisc);
671 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
672 				const struct Qdisc_ops *ops, u32 parentid,
673 				struct netlink_ext_ack *extack);
674 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
675 			       const struct qdisc_size_table *stab);
676 int skb_do_redirect(struct sk_buff *);
677 
678 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
679 {
680 #ifdef CONFIG_NET_CLS_ACT
681 	return skb->tc_at_ingress;
682 #else
683 	return false;
684 #endif
685 }
686 
687 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
688 {
689 #ifdef CONFIG_NET_CLS_ACT
690 	if (skb->tc_skip_classify) {
691 		skb->tc_skip_classify = 0;
692 		return true;
693 	}
694 #endif
695 	return false;
696 }
697 
698 /* Reset all TX qdiscs greater than index of a device.  */
699 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
700 {
701 	struct Qdisc *qdisc;
702 
703 	for (; i < dev->num_tx_queues; i++) {
704 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
705 		if (qdisc) {
706 			spin_lock_bh(qdisc_lock(qdisc));
707 			qdisc_reset(qdisc);
708 			spin_unlock_bh(qdisc_lock(qdisc));
709 		}
710 	}
711 }
712 
713 static inline void qdisc_reset_all_tx(struct net_device *dev)
714 {
715 	qdisc_reset_all_tx_gt(dev, 0);
716 }
717 
718 /* Are all TX queues of the device empty?  */
719 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
720 {
721 	unsigned int i;
722 
723 	rcu_read_lock();
724 	for (i = 0; i < dev->num_tx_queues; i++) {
725 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
726 		const struct Qdisc *q = rcu_dereference(txq->qdisc);
727 
728 		if (!qdisc_is_empty(q)) {
729 			rcu_read_unlock();
730 			return false;
731 		}
732 	}
733 	rcu_read_unlock();
734 	return true;
735 }
736 
737 /* Are any of the TX qdiscs changing?  */
738 static inline bool qdisc_tx_changing(const struct net_device *dev)
739 {
740 	unsigned int i;
741 
742 	for (i = 0; i < dev->num_tx_queues; i++) {
743 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
744 		if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
745 			return true;
746 	}
747 	return false;
748 }
749 
750 /* Is the device using the noop qdisc on all queues?  */
751 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
752 {
753 	unsigned int i;
754 
755 	for (i = 0; i < dev->num_tx_queues; i++) {
756 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
757 		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
758 			return false;
759 	}
760 	return true;
761 }
762 
763 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
764 {
765 	return qdisc_skb_cb(skb)->pkt_len;
766 }
767 
768 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
769 enum net_xmit_qdisc_t {
770 	__NET_XMIT_STOLEN = 0x00010000,
771 	__NET_XMIT_BYPASS = 0x00020000,
772 };
773 
774 #ifdef CONFIG_NET_CLS_ACT
775 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
776 #else
777 #define net_xmit_drop_count(e)	(1)
778 #endif
779 
780 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
781 					   const struct Qdisc *sch)
782 {
783 #ifdef CONFIG_NET_SCHED
784 	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
785 
786 	if (stab)
787 		__qdisc_calculate_pkt_len(skb, stab);
788 #endif
789 }
790 
791 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
792 				struct sk_buff **to_free)
793 {
794 	qdisc_calculate_pkt_len(skb, sch);
795 	return sch->enqueue(skb, sch, to_free);
796 }
797 
798 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
799 				  __u64 bytes, __u32 packets)
800 {
801 	bstats->bytes += bytes;
802 	bstats->packets += packets;
803 }
804 
805 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
806 				 const struct sk_buff *skb)
807 {
808 	_bstats_update(bstats,
809 		       qdisc_pkt_len(skb),
810 		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
811 }
812 
813 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
814 				      __u64 bytes, __u32 packets)
815 {
816 	u64_stats_update_begin(&bstats->syncp);
817 	_bstats_update(&bstats->bstats, bytes, packets);
818 	u64_stats_update_end(&bstats->syncp);
819 }
820 
821 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
822 				     const struct sk_buff *skb)
823 {
824 	u64_stats_update_begin(&bstats->syncp);
825 	bstats_update(&bstats->bstats, skb);
826 	u64_stats_update_end(&bstats->syncp);
827 }
828 
829 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
830 					   const struct sk_buff *skb)
831 {
832 	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
833 }
834 
835 static inline void qdisc_bstats_update(struct Qdisc *sch,
836 				       const struct sk_buff *skb)
837 {
838 	bstats_update(&sch->bstats, skb);
839 }
840 
841 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
842 					    const struct sk_buff *skb)
843 {
844 	sch->qstats.backlog -= qdisc_pkt_len(skb);
845 }
846 
847 static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
848 						const struct sk_buff *skb)
849 {
850 	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
851 }
852 
853 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
854 					    const struct sk_buff *skb)
855 {
856 	sch->qstats.backlog += qdisc_pkt_len(skb);
857 }
858 
859 static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
860 						const struct sk_buff *skb)
861 {
862 	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
863 }
864 
865 static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
866 {
867 	this_cpu_inc(sch->cpu_qstats->qlen);
868 }
869 
870 static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
871 {
872 	this_cpu_dec(sch->cpu_qstats->qlen);
873 }
874 
875 static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
876 {
877 	this_cpu_inc(sch->cpu_qstats->requeues);
878 }
879 
880 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
881 {
882 	sch->qstats.drops += count;
883 }
884 
885 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
886 {
887 	qstats->drops++;
888 }
889 
890 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
891 {
892 	qstats->overlimits++;
893 }
894 
895 static inline void qdisc_qstats_drop(struct Qdisc *sch)
896 {
897 	qstats_drop_inc(&sch->qstats);
898 }
899 
900 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
901 {
902 	this_cpu_inc(sch->cpu_qstats->drops);
903 }
904 
905 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
906 {
907 	sch->qstats.overlimits++;
908 }
909 
910 static inline int qdisc_qstats_copy(struct gnet_dump *d, struct Qdisc *sch)
911 {
912 	__u32 qlen = qdisc_qlen_sum(sch);
913 
914 	return gnet_stats_copy_queue(d, sch->cpu_qstats, &sch->qstats, qlen);
915 }
916 
917 static inline void qdisc_qstats_qlen_backlog(struct Qdisc *sch,  __u32 *qlen,
918 					     __u32 *backlog)
919 {
920 	struct gnet_stats_queue qstats = { 0 };
921 	__u32 len = qdisc_qlen_sum(sch);
922 
923 	__gnet_stats_copy_queue(&qstats, sch->cpu_qstats, &sch->qstats, len);
924 	*qlen = qstats.qlen;
925 	*backlog = qstats.backlog;
926 }
927 
928 static inline void qdisc_tree_flush_backlog(struct Qdisc *sch)
929 {
930 	__u32 qlen, backlog;
931 
932 	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
933 	qdisc_tree_reduce_backlog(sch, qlen, backlog);
934 }
935 
936 static inline void qdisc_purge_queue(struct Qdisc *sch)
937 {
938 	__u32 qlen, backlog;
939 
940 	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
941 	qdisc_reset(sch);
942 	qdisc_tree_reduce_backlog(sch, qlen, backlog);
943 }
944 
945 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
946 {
947 	qh->head = NULL;
948 	qh->tail = NULL;
949 	qh->qlen = 0;
950 }
951 
952 static inline void __qdisc_enqueue_tail(struct sk_buff *skb,
953 					struct qdisc_skb_head *qh)
954 {
955 	struct sk_buff *last = qh->tail;
956 
957 	if (last) {
958 		skb->next = NULL;
959 		last->next = skb;
960 		qh->tail = skb;
961 	} else {
962 		qh->tail = skb;
963 		qh->head = skb;
964 	}
965 	qh->qlen++;
966 }
967 
968 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
969 {
970 	__qdisc_enqueue_tail(skb, &sch->q);
971 	qdisc_qstats_backlog_inc(sch, skb);
972 	return NET_XMIT_SUCCESS;
973 }
974 
975 static inline void __qdisc_enqueue_head(struct sk_buff *skb,
976 					struct qdisc_skb_head *qh)
977 {
978 	skb->next = qh->head;
979 
980 	if (!qh->head)
981 		qh->tail = skb;
982 	qh->head = skb;
983 	qh->qlen++;
984 }
985 
986 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
987 {
988 	struct sk_buff *skb = qh->head;
989 
990 	if (likely(skb != NULL)) {
991 		qh->head = skb->next;
992 		qh->qlen--;
993 		if (qh->head == NULL)
994 			qh->tail = NULL;
995 		skb->next = NULL;
996 	}
997 
998 	return skb;
999 }
1000 
1001 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
1002 {
1003 	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
1004 
1005 	if (likely(skb != NULL)) {
1006 		qdisc_qstats_backlog_dec(sch, skb);
1007 		qdisc_bstats_update(sch, skb);
1008 	}
1009 
1010 	return skb;
1011 }
1012 
1013 /* Instead of calling kfree_skb() while root qdisc lock is held,
1014  * queue the skb for future freeing at end of __dev_xmit_skb()
1015  */
1016 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
1017 {
1018 	skb->next = *to_free;
1019 	*to_free = skb;
1020 }
1021 
1022 static inline void __qdisc_drop_all(struct sk_buff *skb,
1023 				    struct sk_buff **to_free)
1024 {
1025 	if (skb->prev)
1026 		skb->prev->next = *to_free;
1027 	else
1028 		skb->next = *to_free;
1029 	*to_free = skb;
1030 }
1031 
1032 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
1033 						   struct qdisc_skb_head *qh,
1034 						   struct sk_buff **to_free)
1035 {
1036 	struct sk_buff *skb = __qdisc_dequeue_head(qh);
1037 
1038 	if (likely(skb != NULL)) {
1039 		unsigned int len = qdisc_pkt_len(skb);
1040 
1041 		qdisc_qstats_backlog_dec(sch, skb);
1042 		__qdisc_drop(skb, to_free);
1043 		return len;
1044 	}
1045 
1046 	return 0;
1047 }
1048 
1049 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch,
1050 						 struct sk_buff **to_free)
1051 {
1052 	return __qdisc_queue_drop_head(sch, &sch->q, to_free);
1053 }
1054 
1055 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
1056 {
1057 	const struct qdisc_skb_head *qh = &sch->q;
1058 
1059 	return qh->head;
1060 }
1061 
1062 /* generic pseudo peek method for non-work-conserving qdisc */
1063 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
1064 {
1065 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1066 
1067 	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
1068 	if (!skb) {
1069 		skb = sch->dequeue(sch);
1070 
1071 		if (skb) {
1072 			__skb_queue_head(&sch->gso_skb, skb);
1073 			/* it's still part of the queue */
1074 			qdisc_qstats_backlog_inc(sch, skb);
1075 			sch->q.qlen++;
1076 		}
1077 	}
1078 
1079 	return skb;
1080 }
1081 
1082 static inline void qdisc_update_stats_at_dequeue(struct Qdisc *sch,
1083 						 struct sk_buff *skb)
1084 {
1085 	if (qdisc_is_percpu_stats(sch)) {
1086 		qdisc_qstats_cpu_backlog_dec(sch, skb);
1087 		qdisc_bstats_cpu_update(sch, skb);
1088 		qdisc_qstats_cpu_qlen_dec(sch);
1089 	} else {
1090 		qdisc_qstats_backlog_dec(sch, skb);
1091 		qdisc_bstats_update(sch, skb);
1092 		sch->q.qlen--;
1093 	}
1094 }
1095 
1096 static inline void qdisc_update_stats_at_enqueue(struct Qdisc *sch,
1097 						 unsigned int pkt_len)
1098 {
1099 	if (qdisc_is_percpu_stats(sch)) {
1100 		qdisc_qstats_cpu_qlen_inc(sch);
1101 		this_cpu_add(sch->cpu_qstats->backlog, pkt_len);
1102 	} else {
1103 		sch->qstats.backlog += pkt_len;
1104 		sch->q.qlen++;
1105 	}
1106 }
1107 
1108 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
1109 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
1110 {
1111 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1112 
1113 	if (skb) {
1114 		skb = __skb_dequeue(&sch->gso_skb);
1115 		if (qdisc_is_percpu_stats(sch)) {
1116 			qdisc_qstats_cpu_backlog_dec(sch, skb);
1117 			qdisc_qstats_cpu_qlen_dec(sch);
1118 		} else {
1119 			qdisc_qstats_backlog_dec(sch, skb);
1120 			sch->q.qlen--;
1121 		}
1122 	} else {
1123 		skb = sch->dequeue(sch);
1124 	}
1125 
1126 	return skb;
1127 }
1128 
1129 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
1130 {
1131 	/*
1132 	 * We do not know the backlog in bytes of this list, it
1133 	 * is up to the caller to correct it
1134 	 */
1135 	ASSERT_RTNL();
1136 	if (qh->qlen) {
1137 		rtnl_kfree_skbs(qh->head, qh->tail);
1138 
1139 		qh->head = NULL;
1140 		qh->tail = NULL;
1141 		qh->qlen = 0;
1142 	}
1143 }
1144 
1145 static inline void qdisc_reset_queue(struct Qdisc *sch)
1146 {
1147 	__qdisc_reset_queue(&sch->q);
1148 	sch->qstats.backlog = 0;
1149 }
1150 
1151 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
1152 					  struct Qdisc **pold)
1153 {
1154 	struct Qdisc *old;
1155 
1156 	sch_tree_lock(sch);
1157 	old = *pold;
1158 	*pold = new;
1159 	if (old != NULL)
1160 		qdisc_tree_flush_backlog(old);
1161 	sch_tree_unlock(sch);
1162 
1163 	return old;
1164 }
1165 
1166 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
1167 {
1168 	rtnl_kfree_skbs(skb, skb);
1169 	qdisc_qstats_drop(sch);
1170 }
1171 
1172 static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
1173 				 struct sk_buff **to_free)
1174 {
1175 	__qdisc_drop(skb, to_free);
1176 	qdisc_qstats_cpu_drop(sch);
1177 
1178 	return NET_XMIT_DROP;
1179 }
1180 
1181 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
1182 			     struct sk_buff **to_free)
1183 {
1184 	__qdisc_drop(skb, to_free);
1185 	qdisc_qstats_drop(sch);
1186 
1187 	return NET_XMIT_DROP;
1188 }
1189 
1190 static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
1191 				 struct sk_buff **to_free)
1192 {
1193 	__qdisc_drop_all(skb, to_free);
1194 	qdisc_qstats_drop(sch);
1195 
1196 	return NET_XMIT_DROP;
1197 }
1198 
1199 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
1200    long it will take to send a packet given its size.
1201  */
1202 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
1203 {
1204 	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
1205 	if (slot < 0)
1206 		slot = 0;
1207 	slot >>= rtab->rate.cell_log;
1208 	if (slot > 255)
1209 		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
1210 	return rtab->data[slot];
1211 }
1212 
1213 struct psched_ratecfg {
1214 	u64	rate_bytes_ps; /* bytes per second */
1215 	u32	mult;
1216 	u16	overhead;
1217 	u8	linklayer;
1218 	u8	shift;
1219 };
1220 
1221 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
1222 				unsigned int len)
1223 {
1224 	len += r->overhead;
1225 
1226 	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
1227 		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
1228 
1229 	return ((u64)len * r->mult) >> r->shift;
1230 }
1231 
1232 void psched_ratecfg_precompute(struct psched_ratecfg *r,
1233 			       const struct tc_ratespec *conf,
1234 			       u64 rate64);
1235 
1236 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
1237 					  const struct psched_ratecfg *r)
1238 {
1239 	memset(res, 0, sizeof(*res));
1240 
1241 	/* legacy struct tc_ratespec has a 32bit @rate field
1242 	 * Qdisc using 64bit rate should add new attributes
1243 	 * in order to maintain compatibility.
1244 	 */
1245 	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
1246 
1247 	res->overhead = r->overhead;
1248 	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
1249 }
1250 
1251 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
1252  * The fast path only needs to access filter list and to update stats
1253  */
1254 struct mini_Qdisc {
1255 	struct tcf_proto *filter_list;
1256 	struct tcf_block *block;
1257 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
1258 	struct gnet_stats_queue	__percpu *cpu_qstats;
1259 	struct rcu_head rcu;
1260 };
1261 
1262 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
1263 						const struct sk_buff *skb)
1264 {
1265 	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
1266 }
1267 
1268 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
1269 {
1270 	this_cpu_inc(miniq->cpu_qstats->drops);
1271 }
1272 
1273 struct mini_Qdisc_pair {
1274 	struct mini_Qdisc miniq1;
1275 	struct mini_Qdisc miniq2;
1276 	struct mini_Qdisc __rcu **p_miniq;
1277 };
1278 
1279 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
1280 			  struct tcf_proto *tp_head);
1281 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
1282 			  struct mini_Qdisc __rcu **p_miniq);
1283 void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,
1284 				struct tcf_block *block);
1285 
1286 static inline int skb_tc_reinsert(struct sk_buff *skb, struct tcf_result *res)
1287 {
1288 	return res->ingress ? netif_receive_skb(skb) : dev_queue_xmit(skb);
1289 }
1290 
1291 #endif
1292