xref: /linux/include/net/sch_generic.h (revision 93d546399c2b7d66a54d5fbd5eee17de19246bf6)
1 #ifndef __NET_SCHED_GENERIC_H
2 #define __NET_SCHED_GENERIC_H
3 
4 #include <linux/netdevice.h>
5 #include <linux/types.h>
6 #include <linux/rcupdate.h>
7 #include <linux/module.h>
8 #include <linux/pkt_sched.h>
9 #include <linux/pkt_cls.h>
10 #include <net/gen_stats.h>
11 #include <net/rtnetlink.h>
12 
13 struct Qdisc_ops;
14 struct qdisc_walker;
15 struct tcf_walker;
16 struct module;
17 
18 struct qdisc_rate_table
19 {
20 	struct tc_ratespec rate;
21 	u32		data[256];
22 	struct qdisc_rate_table *next;
23 	int		refcnt;
24 };
25 
26 enum qdisc_state_t
27 {
28 	__QDISC_STATE_RUNNING,
29 	__QDISC_STATE_SCHED,
30 	__QDISC_STATE_DEACTIVATED,
31 };
32 
33 struct qdisc_size_table {
34 	struct list_head	list;
35 	struct tc_sizespec	szopts;
36 	int			refcnt;
37 	u16			data[];
38 };
39 
40 struct Qdisc
41 {
42 	int 			(*enqueue)(struct sk_buff *skb, struct Qdisc *dev);
43 	struct sk_buff *	(*dequeue)(struct Qdisc *dev);
44 	unsigned		flags;
45 #define TCQ_F_BUILTIN	1
46 #define TCQ_F_THROTTLED	2
47 #define TCQ_F_INGRESS	4
48 	int			padded;
49 	struct Qdisc_ops	*ops;
50 	struct qdisc_size_table	*stab;
51 	u32			handle;
52 	u32			parent;
53 	atomic_t		refcnt;
54 	unsigned long		state;
55 	struct sk_buff		*gso_skb;
56 	struct sk_buff_head	requeue;
57 	struct sk_buff_head	q;
58 	struct netdev_queue	*dev_queue;
59 	struct Qdisc		*next_sched;
60 	struct list_head	list;
61 
62 	struct gnet_stats_basic	bstats;
63 	struct gnet_stats_queue	qstats;
64 	struct gnet_stats_rate_est	rate_est;
65 	int			(*reshape_fail)(struct sk_buff *skb,
66 					struct Qdisc *q);
67 
68 	void			*u32_node;
69 
70 	/* This field is deprecated, but it is still used by CBQ
71 	 * and it will live until better solution will be invented.
72 	 */
73 	struct Qdisc		*__parent;
74 };
75 
76 struct Qdisc_class_ops
77 {
78 	/* Child qdisc manipulation */
79 	int			(*graft)(struct Qdisc *, unsigned long cl,
80 					struct Qdisc *, struct Qdisc **);
81 	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);
82 	void			(*qlen_notify)(struct Qdisc *, unsigned long);
83 
84 	/* Class manipulation routines */
85 	unsigned long		(*get)(struct Qdisc *, u32 classid);
86 	void			(*put)(struct Qdisc *, unsigned long);
87 	int			(*change)(struct Qdisc *, u32, u32,
88 					struct nlattr **, unsigned long *);
89 	int			(*delete)(struct Qdisc *, unsigned long);
90 	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);
91 
92 	/* Filter manipulation */
93 	struct tcf_proto **	(*tcf_chain)(struct Qdisc *, unsigned long);
94 	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
95 					u32 classid);
96 	void			(*unbind_tcf)(struct Qdisc *, unsigned long);
97 
98 	/* rtnetlink specific */
99 	int			(*dump)(struct Qdisc *, unsigned long,
100 					struct sk_buff *skb, struct tcmsg*);
101 	int			(*dump_stats)(struct Qdisc *, unsigned long,
102 					struct gnet_dump *);
103 };
104 
105 struct Qdisc_ops
106 {
107 	struct Qdisc_ops	*next;
108 	const struct Qdisc_class_ops	*cl_ops;
109 	char			id[IFNAMSIZ];
110 	int			priv_size;
111 
112 	int 			(*enqueue)(struct sk_buff *, struct Qdisc *);
113 	struct sk_buff *	(*dequeue)(struct Qdisc *);
114 	int 			(*requeue)(struct sk_buff *, struct Qdisc *);
115 	unsigned int		(*drop)(struct Qdisc *);
116 
117 	int			(*init)(struct Qdisc *, struct nlattr *arg);
118 	void			(*reset)(struct Qdisc *);
119 	void			(*destroy)(struct Qdisc *);
120 	int			(*change)(struct Qdisc *, struct nlattr *arg);
121 
122 	int			(*dump)(struct Qdisc *, struct sk_buff *);
123 	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);
124 
125 	struct module		*owner;
126 };
127 
128 
129 struct tcf_result
130 {
131 	unsigned long	class;
132 	u32		classid;
133 };
134 
135 struct tcf_proto_ops
136 {
137 	struct tcf_proto_ops	*next;
138 	char			kind[IFNAMSIZ];
139 
140 	int			(*classify)(struct sk_buff*, struct tcf_proto*,
141 					struct tcf_result *);
142 	int			(*init)(struct tcf_proto*);
143 	void			(*destroy)(struct tcf_proto*);
144 
145 	unsigned long		(*get)(struct tcf_proto*, u32 handle);
146 	void			(*put)(struct tcf_proto*, unsigned long);
147 	int			(*change)(struct tcf_proto*, unsigned long,
148 					u32 handle, struct nlattr **,
149 					unsigned long *);
150 	int			(*delete)(struct tcf_proto*, unsigned long);
151 	void			(*walk)(struct tcf_proto*, struct tcf_walker *arg);
152 
153 	/* rtnetlink specific */
154 	int			(*dump)(struct tcf_proto*, unsigned long,
155 					struct sk_buff *skb, struct tcmsg*);
156 
157 	struct module		*owner;
158 };
159 
160 struct tcf_proto
161 {
162 	/* Fast access part */
163 	struct tcf_proto	*next;
164 	void			*root;
165 	int			(*classify)(struct sk_buff*, struct tcf_proto*,
166 					struct tcf_result *);
167 	__be16			protocol;
168 
169 	/* All the rest */
170 	u32			prio;
171 	u32			classid;
172 	struct Qdisc		*q;
173 	void			*data;
174 	struct tcf_proto_ops	*ops;
175 };
176 
177 struct qdisc_skb_cb {
178 	unsigned int		pkt_len;
179 	char			data[];
180 };
181 
182 static inline struct qdisc_skb_cb *qdisc_skb_cb(struct sk_buff *skb)
183 {
184 	return (struct qdisc_skb_cb *)skb->cb;
185 }
186 
187 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
188 {
189 	return &qdisc->q.lock;
190 }
191 
192 static inline struct Qdisc *qdisc_root(struct Qdisc *qdisc)
193 {
194 	return qdisc->dev_queue->qdisc;
195 }
196 
197 static inline struct Qdisc *qdisc_root_sleeping(struct Qdisc *qdisc)
198 {
199 	return qdisc->dev_queue->qdisc_sleeping;
200 }
201 
202 /* The qdisc root lock is a mechanism by which to top level
203  * of a qdisc tree can be locked from any qdisc node in the
204  * forest.  This allows changing the configuration of some
205  * aspect of the qdisc tree while blocking out asynchronous
206  * qdisc access in the packet processing paths.
207  *
208  * It is only legal to do this when the root will not change
209  * on us.  Otherwise we'll potentially lock the wrong qdisc
210  * root.  This is enforced by holding the RTNL semaphore, which
211  * all users of this lock accessor must do.
212  */
213 static inline spinlock_t *qdisc_root_lock(struct Qdisc *qdisc)
214 {
215 	struct Qdisc *root = qdisc_root(qdisc);
216 
217 	ASSERT_RTNL();
218 	return qdisc_lock(root);
219 }
220 
221 static inline spinlock_t *qdisc_root_sleeping_lock(struct Qdisc *qdisc)
222 {
223 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
224 
225 	ASSERT_RTNL();
226 	return qdisc_lock(root);
227 }
228 
229 static inline struct net_device *qdisc_dev(struct Qdisc *qdisc)
230 {
231 	return qdisc->dev_queue->dev;
232 }
233 
234 static inline void sch_tree_lock(struct Qdisc *q)
235 {
236 	spin_lock_bh(qdisc_root_sleeping_lock(q));
237 }
238 
239 static inline void sch_tree_unlock(struct Qdisc *q)
240 {
241 	spin_unlock_bh(qdisc_root_sleeping_lock(q));
242 }
243 
244 #define tcf_tree_lock(tp)	sch_tree_lock((tp)->q)
245 #define tcf_tree_unlock(tp)	sch_tree_unlock((tp)->q)
246 
247 extern struct Qdisc noop_qdisc;
248 extern struct Qdisc_ops noop_qdisc_ops;
249 
250 struct Qdisc_class_common
251 {
252 	u32			classid;
253 	struct hlist_node	hnode;
254 };
255 
256 struct Qdisc_class_hash
257 {
258 	struct hlist_head	*hash;
259 	unsigned int		hashsize;
260 	unsigned int		hashmask;
261 	unsigned int		hashelems;
262 };
263 
264 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
265 {
266 	id ^= id >> 8;
267 	id ^= id >> 4;
268 	return id & mask;
269 }
270 
271 static inline struct Qdisc_class_common *
272 qdisc_class_find(struct Qdisc_class_hash *hash, u32 id)
273 {
274 	struct Qdisc_class_common *cl;
275 	struct hlist_node *n;
276 	unsigned int h;
277 
278 	h = qdisc_class_hash(id, hash->hashmask);
279 	hlist_for_each_entry(cl, n, &hash->hash[h], hnode) {
280 		if (cl->classid == id)
281 			return cl;
282 	}
283 	return NULL;
284 }
285 
286 extern int qdisc_class_hash_init(struct Qdisc_class_hash *);
287 extern void qdisc_class_hash_insert(struct Qdisc_class_hash *, struct Qdisc_class_common *);
288 extern void qdisc_class_hash_remove(struct Qdisc_class_hash *, struct Qdisc_class_common *);
289 extern void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
290 extern void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
291 
292 extern void dev_init_scheduler(struct net_device *dev);
293 extern void dev_shutdown(struct net_device *dev);
294 extern void dev_activate(struct net_device *dev);
295 extern void dev_deactivate(struct net_device *dev);
296 extern void qdisc_reset(struct Qdisc *qdisc);
297 extern void qdisc_destroy(struct Qdisc *qdisc);
298 extern void qdisc_tree_decrease_qlen(struct Qdisc *qdisc, unsigned int n);
299 extern struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
300 				 struct Qdisc_ops *ops);
301 extern struct Qdisc *qdisc_create_dflt(struct net_device *dev,
302 				       struct netdev_queue *dev_queue,
303 				       struct Qdisc_ops *ops, u32 parentid);
304 extern void qdisc_calculate_pkt_len(struct sk_buff *skb,
305 				   struct qdisc_size_table *stab);
306 extern void tcf_destroy(struct tcf_proto *tp);
307 extern void tcf_destroy_chain(struct tcf_proto **fl);
308 
309 /* Reset all TX qdiscs of a device.  */
310 static inline void qdisc_reset_all_tx(struct net_device *dev)
311 {
312 	unsigned int i;
313 	for (i = 0; i < dev->num_tx_queues; i++)
314 		qdisc_reset(netdev_get_tx_queue(dev, i)->qdisc);
315 }
316 
317 /* Are all TX queues of the device empty?  */
318 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
319 {
320 	unsigned int i;
321 	for (i = 0; i < dev->num_tx_queues; i++) {
322 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
323 		const struct Qdisc *q = txq->qdisc;
324 
325 		if (q->q.qlen)
326 			return false;
327 	}
328 	return true;
329 }
330 
331 /* Are any of the TX qdiscs changing?  */
332 static inline bool qdisc_tx_changing(struct net_device *dev)
333 {
334 	unsigned int i;
335 	for (i = 0; i < dev->num_tx_queues; i++) {
336 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
337 		if (txq->qdisc != txq->qdisc_sleeping)
338 			return true;
339 	}
340 	return false;
341 }
342 
343 /* Is the device using the noop qdisc on all queues?  */
344 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
345 {
346 	unsigned int i;
347 	for (i = 0; i < dev->num_tx_queues; i++) {
348 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
349 		if (txq->qdisc != &noop_qdisc)
350 			return false;
351 	}
352 	return true;
353 }
354 
355 static inline unsigned int qdisc_pkt_len(struct sk_buff *skb)
356 {
357 	return qdisc_skb_cb(skb)->pkt_len;
358 }
359 
360 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
361 enum net_xmit_qdisc_t {
362 	__NET_XMIT_STOLEN = 0x00010000,
363 	__NET_XMIT_BYPASS = 0x00020000,
364 };
365 
366 #ifdef CONFIG_NET_CLS_ACT
367 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
368 #else
369 #define net_xmit_drop_count(e)	(1)
370 #endif
371 
372 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
373 {
374 #ifdef CONFIG_NET_SCHED
375 	if (sch->stab)
376 		qdisc_calculate_pkt_len(skb, sch->stab);
377 #endif
378 	return sch->enqueue(skb, sch);
379 }
380 
381 static inline int qdisc_enqueue_root(struct sk_buff *skb, struct Qdisc *sch)
382 {
383 	qdisc_skb_cb(skb)->pkt_len = skb->len;
384 	return qdisc_enqueue(skb, sch) & NET_XMIT_MASK;
385 }
386 
387 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
388 				       struct sk_buff_head *list)
389 {
390 	__skb_queue_tail(list, skb);
391 	sch->qstats.backlog += qdisc_pkt_len(skb);
392 	sch->bstats.bytes += qdisc_pkt_len(skb);
393 	sch->bstats.packets++;
394 
395 	return NET_XMIT_SUCCESS;
396 }
397 
398 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
399 {
400 	return __qdisc_enqueue_tail(skb, sch, &sch->q);
401 }
402 
403 static inline struct sk_buff *__qdisc_dequeue_head(struct Qdisc *sch,
404 						   struct sk_buff_head *list)
405 {
406 	struct sk_buff *skb = __skb_dequeue(list);
407 
408 	if (likely(skb != NULL))
409 		sch->qstats.backlog -= qdisc_pkt_len(skb);
410 
411 	return skb;
412 }
413 
414 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
415 {
416 	return __qdisc_dequeue_head(sch, &sch->q);
417 }
418 
419 static inline struct sk_buff *__qdisc_dequeue_tail(struct Qdisc *sch,
420 						   struct sk_buff_head *list)
421 {
422 	struct sk_buff *skb = __skb_dequeue_tail(list);
423 
424 	if (likely(skb != NULL))
425 		sch->qstats.backlog -= qdisc_pkt_len(skb);
426 
427 	return skb;
428 }
429 
430 static inline struct sk_buff *qdisc_dequeue_tail(struct Qdisc *sch)
431 {
432 	return __qdisc_dequeue_tail(sch, &sch->q);
433 }
434 
435 static inline int __qdisc_requeue(struct sk_buff *skb, struct Qdisc *sch,
436 				  struct sk_buff_head *list)
437 {
438 	__skb_queue_head(list, skb);
439 	sch->qstats.backlog += qdisc_pkt_len(skb);
440 	sch->qstats.requeues++;
441 
442 	return NET_XMIT_SUCCESS;
443 }
444 
445 static inline int qdisc_requeue(struct sk_buff *skb, struct Qdisc *sch)
446 {
447 	return __qdisc_requeue(skb, sch, &sch->q);
448 }
449 
450 static inline void __qdisc_reset_queue(struct Qdisc *sch,
451 				       struct sk_buff_head *list)
452 {
453 	/*
454 	 * We do not know the backlog in bytes of this list, it
455 	 * is up to the caller to correct it
456 	 */
457 	__skb_queue_purge(list);
458 }
459 
460 static inline void qdisc_reset_queue(struct Qdisc *sch)
461 {
462 	__qdisc_reset_queue(sch, &sch->q);
463 	sch->qstats.backlog = 0;
464 }
465 
466 static inline unsigned int __qdisc_queue_drop(struct Qdisc *sch,
467 					      struct sk_buff_head *list)
468 {
469 	struct sk_buff *skb = __qdisc_dequeue_tail(sch, list);
470 
471 	if (likely(skb != NULL)) {
472 		unsigned int len = qdisc_pkt_len(skb);
473 		kfree_skb(skb);
474 		return len;
475 	}
476 
477 	return 0;
478 }
479 
480 static inline unsigned int qdisc_queue_drop(struct Qdisc *sch)
481 {
482 	return __qdisc_queue_drop(sch, &sch->q);
483 }
484 
485 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
486 {
487 	kfree_skb(skb);
488 	sch->qstats.drops++;
489 
490 	return NET_XMIT_DROP;
491 }
492 
493 static inline int qdisc_reshape_fail(struct sk_buff *skb, struct Qdisc *sch)
494 {
495 	sch->qstats.drops++;
496 
497 #ifdef CONFIG_NET_CLS_ACT
498 	if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))
499 		goto drop;
500 
501 	return NET_XMIT_SUCCESS;
502 
503 drop:
504 #endif
505 	kfree_skb(skb);
506 	return NET_XMIT_DROP;
507 }
508 
509 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
510    long it will take to send a packet given its size.
511  */
512 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
513 {
514 	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
515 	if (slot < 0)
516 		slot = 0;
517 	slot >>= rtab->rate.cell_log;
518 	if (slot > 255)
519 		return (rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF]);
520 	return rtab->data[slot];
521 }
522 
523 #ifdef CONFIG_NET_CLS_ACT
524 static inline struct sk_buff *skb_act_clone(struct sk_buff *skb, gfp_t gfp_mask)
525 {
526 	struct sk_buff *n = skb_clone(skb, gfp_mask);
527 
528 	if (n) {
529 		n->tc_verd = SET_TC_VERD(n->tc_verd, 0);
530 		n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd);
531 		n->tc_verd = CLR_TC_MUNGED(n->tc_verd);
532 	}
533 	return n;
534 }
535 #endif
536 
537 #endif
538