xref: /linux/net/shaper/shaper.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 #include <linux/bits.h>
4 #include <linux/bitfield.h>
5 #include <linux/idr.h>
6 #include <linux/kernel.h>
7 #include <linux/netdevice.h>
8 #include <linux/netlink.h>
9 #include <linux/skbuff.h>
10 #include <linux/xarray.h>
11 #include <net/devlink.h>
12 #include <net/net_shaper.h>
13 
14 #include "shaper_nl_gen.h"
15 
16 #include "../core/dev.h"
17 
18 #define NET_SHAPER_SCOPE_SHIFT	26
19 #define NET_SHAPER_ID_MASK	GENMASK(NET_SHAPER_SCOPE_SHIFT - 1, 0)
20 #define NET_SHAPER_SCOPE_MASK	GENMASK(31, NET_SHAPER_SCOPE_SHIFT)
21 
22 #define NET_SHAPER_ID_UNSPEC NET_SHAPER_ID_MASK
23 
24 struct net_shaper_hierarchy {
25 	struct xarray shapers;
26 };
27 
28 struct net_shaper_nl_ctx {
29 	struct net_shaper_binding binding;
30 	netdevice_tracker dev_tracker;
31 	unsigned long start_index;
32 };
33 
34 static struct net_shaper_binding *net_shaper_binding_from_ctx(void *ctx)
35 {
36 	return &((struct net_shaper_nl_ctx *)ctx)->binding;
37 }
38 
39 static void net_shaper_lock(struct net_shaper_binding *binding)
40 {
41 	switch (binding->type) {
42 	case NET_SHAPER_BINDING_TYPE_NETDEV:
43 		mutex_lock(&binding->netdev->lock);
44 		break;
45 	}
46 }
47 
48 static void net_shaper_unlock(struct net_shaper_binding *binding)
49 {
50 	switch (binding->type) {
51 	case NET_SHAPER_BINDING_TYPE_NETDEV:
52 		mutex_unlock(&binding->netdev->lock);
53 		break;
54 	}
55 }
56 
57 static struct net_shaper_hierarchy *
58 net_shaper_hierarchy(struct net_shaper_binding *binding)
59 {
60 	/* Pairs with WRITE_ONCE() in net_shaper_hierarchy_setup. */
61 	if (binding->type == NET_SHAPER_BINDING_TYPE_NETDEV)
62 		return READ_ONCE(binding->netdev->net_shaper_hierarchy);
63 
64 	/* No other type supported yet. */
65 	return NULL;
66 }
67 
68 static const struct net_shaper_ops *
69 net_shaper_ops(struct net_shaper_binding *binding)
70 {
71 	if (binding->type == NET_SHAPER_BINDING_TYPE_NETDEV)
72 		return binding->netdev->netdev_ops->net_shaper_ops;
73 
74 	/* No other type supported yet. */
75 	return NULL;
76 }
77 
78 /* Count the number of [multi] attributes of the given type. */
79 static int net_shaper_list_len(struct genl_info *info, int type)
80 {
81 	struct nlattr *attr;
82 	int rem, cnt = 0;
83 
84 	nla_for_each_attr_type(attr, type, genlmsg_data(info->genlhdr),
85 			       genlmsg_len(info->genlhdr), rem)
86 		cnt++;
87 	return cnt;
88 }
89 
90 static int net_shaper_handle_size(void)
91 {
92 	return nla_total_size(nla_total_size(sizeof(u32)) +
93 			      nla_total_size(sizeof(u32)));
94 }
95 
96 static int net_shaper_fill_binding(struct sk_buff *msg,
97 				   const struct net_shaper_binding *binding,
98 				   u32 type)
99 {
100 	/* Should never happen, as currently only NETDEV is supported. */
101 	if (WARN_ON_ONCE(binding->type != NET_SHAPER_BINDING_TYPE_NETDEV))
102 		return -EINVAL;
103 
104 	if (nla_put_u32(msg, type, binding->netdev->ifindex))
105 		return -EMSGSIZE;
106 
107 	return 0;
108 }
109 
110 static int net_shaper_fill_handle(struct sk_buff *msg,
111 				  const struct net_shaper_handle *handle,
112 				  u32 type)
113 {
114 	struct nlattr *handle_attr;
115 
116 	if (handle->scope == NET_SHAPER_SCOPE_UNSPEC)
117 		return 0;
118 
119 	handle_attr = nla_nest_start(msg, type);
120 	if (!handle_attr)
121 		return -EMSGSIZE;
122 
123 	if (nla_put_u32(msg, NET_SHAPER_A_HANDLE_SCOPE, handle->scope) ||
124 	    (handle->scope >= NET_SHAPER_SCOPE_QUEUE &&
125 	     nla_put_u32(msg, NET_SHAPER_A_HANDLE_ID, handle->id)))
126 		goto handle_nest_cancel;
127 
128 	nla_nest_end(msg, handle_attr);
129 	return 0;
130 
131 handle_nest_cancel:
132 	nla_nest_cancel(msg, handle_attr);
133 	return -EMSGSIZE;
134 }
135 
136 static int
137 net_shaper_fill_one(struct sk_buff *msg,
138 		    const struct net_shaper_binding *binding,
139 		    const struct net_shaper *shaper,
140 		    const struct genl_info *info)
141 {
142 	void *hdr;
143 
144 	hdr = genlmsg_iput(msg, info);
145 	if (!hdr)
146 		return -EMSGSIZE;
147 
148 	if (net_shaper_fill_binding(msg, binding, NET_SHAPER_A_IFINDEX) ||
149 	    net_shaper_fill_handle(msg, &shaper->parent,
150 				   NET_SHAPER_A_PARENT) ||
151 	    net_shaper_fill_handle(msg, &shaper->handle,
152 				   NET_SHAPER_A_HANDLE) ||
153 	    ((shaper->bw_min || shaper->bw_max || shaper->burst) &&
154 	     nla_put_u32(msg, NET_SHAPER_A_METRIC, shaper->metric)) ||
155 	    (shaper->bw_min &&
156 	     nla_put_uint(msg, NET_SHAPER_A_BW_MIN, shaper->bw_min)) ||
157 	    (shaper->bw_max &&
158 	     nla_put_uint(msg, NET_SHAPER_A_BW_MAX, shaper->bw_max)) ||
159 	    (shaper->burst &&
160 	     nla_put_uint(msg, NET_SHAPER_A_BURST, shaper->burst)) ||
161 	    (shaper->priority &&
162 	     nla_put_u32(msg, NET_SHAPER_A_PRIORITY, shaper->priority)) ||
163 	    (shaper->weight &&
164 	     nla_put_u32(msg, NET_SHAPER_A_WEIGHT, shaper->weight)))
165 		goto nla_put_failure;
166 
167 	genlmsg_end(msg, hdr);
168 
169 	return 0;
170 
171 nla_put_failure:
172 	genlmsg_cancel(msg, hdr);
173 	return -EMSGSIZE;
174 }
175 
176 /* Initialize the context fetching the relevant device and
177  * acquiring a reference to it.
178  */
179 static int net_shaper_ctx_setup(const struct genl_info *info, int type,
180 				struct net_shaper_nl_ctx *ctx)
181 {
182 	struct net *ns = genl_info_net(info);
183 	struct net_device *dev;
184 	int ifindex;
185 
186 	if (GENL_REQ_ATTR_CHECK(info, type))
187 		return -EINVAL;
188 
189 	ifindex = nla_get_u32(info->attrs[type]);
190 	dev = netdev_get_by_index(ns, ifindex, &ctx->dev_tracker, GFP_KERNEL);
191 	if (!dev) {
192 		NL_SET_BAD_ATTR(info->extack, info->attrs[type]);
193 		return -ENOENT;
194 	}
195 
196 	if (!dev->netdev_ops->net_shaper_ops) {
197 		NL_SET_BAD_ATTR(info->extack, info->attrs[type]);
198 		netdev_put(dev, &ctx->dev_tracker);
199 		return -EOPNOTSUPP;
200 	}
201 
202 	ctx->binding.type = NET_SHAPER_BINDING_TYPE_NETDEV;
203 	ctx->binding.netdev = dev;
204 	return 0;
205 }
206 
207 static void net_shaper_ctx_cleanup(struct net_shaper_nl_ctx *ctx)
208 {
209 	if (ctx->binding.type == NET_SHAPER_BINDING_TYPE_NETDEV)
210 		netdev_put(ctx->binding.netdev, &ctx->dev_tracker);
211 }
212 
213 static u32 net_shaper_handle_to_index(const struct net_shaper_handle *handle)
214 {
215 	return FIELD_PREP(NET_SHAPER_SCOPE_MASK, handle->scope) |
216 		FIELD_PREP(NET_SHAPER_ID_MASK, handle->id);
217 }
218 
219 static void net_shaper_index_to_handle(u32 index,
220 				       struct net_shaper_handle *handle)
221 {
222 	handle->scope = FIELD_GET(NET_SHAPER_SCOPE_MASK, index);
223 	handle->id = FIELD_GET(NET_SHAPER_ID_MASK, index);
224 }
225 
226 static void net_shaper_default_parent(const struct net_shaper_handle *handle,
227 				      struct net_shaper_handle *parent)
228 {
229 	switch (handle->scope) {
230 	case NET_SHAPER_SCOPE_UNSPEC:
231 	case NET_SHAPER_SCOPE_NETDEV:
232 	case __NET_SHAPER_SCOPE_MAX:
233 		parent->scope = NET_SHAPER_SCOPE_UNSPEC;
234 		break;
235 
236 	case NET_SHAPER_SCOPE_QUEUE:
237 	case NET_SHAPER_SCOPE_NODE:
238 		parent->scope = NET_SHAPER_SCOPE_NETDEV;
239 		break;
240 	}
241 	parent->id = 0;
242 }
243 
244 /*
245  * MARK_0 is already in use due to XA_FLAGS_ALLOC, can't reuse such flag as
246  * it's cleared by xa_store().
247  */
248 #define NET_SHAPER_NOT_VALID XA_MARK_1
249 
250 static struct net_shaper *
251 net_shaper_lookup(struct net_shaper_binding *binding,
252 		  const struct net_shaper_handle *handle)
253 {
254 	struct net_shaper_hierarchy *hierarchy = net_shaper_hierarchy(binding);
255 	u32 index = net_shaper_handle_to_index(handle);
256 
257 	if (!hierarchy || xa_get_mark(&hierarchy->shapers, index,
258 				      NET_SHAPER_NOT_VALID))
259 		return NULL;
260 
261 	return xa_load(&hierarchy->shapers, index);
262 }
263 
264 /* Allocate on demand the per device shaper's hierarchy container.
265  * Called under the net shaper lock
266  */
267 static struct net_shaper_hierarchy *
268 net_shaper_hierarchy_setup(struct net_shaper_binding *binding)
269 {
270 	struct net_shaper_hierarchy *hierarchy = net_shaper_hierarchy(binding);
271 
272 	if (hierarchy)
273 		return hierarchy;
274 
275 	hierarchy = kmalloc(sizeof(*hierarchy), GFP_KERNEL);
276 	if (!hierarchy)
277 		return NULL;
278 
279 	/* The flag is required for ID allocation */
280 	xa_init_flags(&hierarchy->shapers, XA_FLAGS_ALLOC);
281 
282 	switch (binding->type) {
283 	case NET_SHAPER_BINDING_TYPE_NETDEV:
284 		/* Pairs with READ_ONCE in net_shaper_hierarchy. */
285 		WRITE_ONCE(binding->netdev->net_shaper_hierarchy, hierarchy);
286 		break;
287 	}
288 	return hierarchy;
289 }
290 
291 /* Prepare the hierarchy container to actually insert the given shaper, doing
292  * in advance the needed allocations.
293  */
294 static int net_shaper_pre_insert(struct net_shaper_binding *binding,
295 				 struct net_shaper_handle *handle,
296 				 struct netlink_ext_ack *extack)
297 {
298 	struct net_shaper_hierarchy *hierarchy = net_shaper_hierarchy(binding);
299 	struct net_shaper *prev, *cur;
300 	bool id_allocated = false;
301 	int ret, index;
302 
303 	if (!hierarchy)
304 		return -ENOMEM;
305 
306 	index = net_shaper_handle_to_index(handle);
307 	cur = xa_load(&hierarchy->shapers, index);
308 	if (cur)
309 		return 0;
310 
311 	/* Allocated a new id, if needed. */
312 	if (handle->scope == NET_SHAPER_SCOPE_NODE &&
313 	    handle->id == NET_SHAPER_ID_UNSPEC) {
314 		u32 min, max;
315 
316 		handle->id = NET_SHAPER_ID_MASK - 1;
317 		max = net_shaper_handle_to_index(handle);
318 		handle->id = 0;
319 		min = net_shaper_handle_to_index(handle);
320 
321 		ret = xa_alloc(&hierarchy->shapers, &index, NULL,
322 			       XA_LIMIT(min, max), GFP_KERNEL);
323 		if (ret < 0) {
324 			NL_SET_ERR_MSG(extack, "Can't allocate new id for NODE shaper");
325 			return ret;
326 		}
327 
328 		net_shaper_index_to_handle(index, handle);
329 		id_allocated = true;
330 	}
331 
332 	cur = kzalloc(sizeof(*cur), GFP_KERNEL);
333 	if (!cur) {
334 		ret = -ENOMEM;
335 		goto free_id;
336 	}
337 
338 	/* Mark 'tentative' shaper inside the hierarchy container.
339 	 * xa_set_mark is a no-op if the previous store fails.
340 	 */
341 	xa_lock(&hierarchy->shapers);
342 	prev = __xa_store(&hierarchy->shapers, index, cur, GFP_KERNEL);
343 	__xa_set_mark(&hierarchy->shapers, index, NET_SHAPER_NOT_VALID);
344 	xa_unlock(&hierarchy->shapers);
345 	if (xa_err(prev)) {
346 		NL_SET_ERR_MSG(extack, "Can't insert shaper into device store");
347 		kfree_rcu(cur, rcu);
348 		ret = xa_err(prev);
349 		goto free_id;
350 	}
351 	return 0;
352 
353 free_id:
354 	if (id_allocated)
355 		xa_erase(&hierarchy->shapers, index);
356 	return ret;
357 }
358 
359 /* Commit the tentative insert with the actual values.
360  * Must be called only after a successful net_shaper_pre_insert().
361  */
362 static void net_shaper_commit(struct net_shaper_binding *binding,
363 			      int nr_shapers, const struct net_shaper *shapers)
364 {
365 	struct net_shaper_hierarchy *hierarchy = net_shaper_hierarchy(binding);
366 	struct net_shaper *cur;
367 	int index;
368 	int i;
369 
370 	xa_lock(&hierarchy->shapers);
371 	for (i = 0; i < nr_shapers; ++i) {
372 		index = net_shaper_handle_to_index(&shapers[i].handle);
373 
374 		cur = xa_load(&hierarchy->shapers, index);
375 		if (WARN_ON_ONCE(!cur))
376 			continue;
377 
378 		/* Successful update: drop the tentative mark
379 		 * and update the hierarchy container.
380 		 */
381 		__xa_clear_mark(&hierarchy->shapers, index,
382 				NET_SHAPER_NOT_VALID);
383 		*cur = shapers[i];
384 	}
385 	xa_unlock(&hierarchy->shapers);
386 }
387 
388 /* Rollback all the tentative inserts from the hierarchy. */
389 static void net_shaper_rollback(struct net_shaper_binding *binding)
390 {
391 	struct net_shaper_hierarchy *hierarchy = net_shaper_hierarchy(binding);
392 	struct net_shaper *cur;
393 	unsigned long index;
394 
395 	if (!hierarchy)
396 		return;
397 
398 	xa_lock(&hierarchy->shapers);
399 	xa_for_each_marked(&hierarchy->shapers, index, cur,
400 			   NET_SHAPER_NOT_VALID) {
401 		__xa_erase(&hierarchy->shapers, index);
402 		kfree(cur);
403 	}
404 	xa_unlock(&hierarchy->shapers);
405 }
406 
407 static int net_shaper_parse_handle(const struct nlattr *attr,
408 				   const struct genl_info *info,
409 				   struct net_shaper_handle *handle)
410 {
411 	struct nlattr *tb[NET_SHAPER_A_HANDLE_MAX + 1];
412 	struct nlattr *id_attr;
413 	u32 id = 0;
414 	int ret;
415 
416 	ret = nla_parse_nested(tb, NET_SHAPER_A_HANDLE_MAX, attr,
417 			       net_shaper_handle_nl_policy, info->extack);
418 	if (ret < 0)
419 		return ret;
420 
421 	if (NL_REQ_ATTR_CHECK(info->extack, attr, tb,
422 			      NET_SHAPER_A_HANDLE_SCOPE))
423 		return -EINVAL;
424 
425 	handle->scope = nla_get_u32(tb[NET_SHAPER_A_HANDLE_SCOPE]);
426 
427 	/* The default id for NODE scope shapers is an invalid one
428 	 * to help the 'group' operation discriminate between new
429 	 * NODE shaper creation (ID_UNSPEC) and reuse of existing
430 	 * shaper (any other value).
431 	 */
432 	id_attr = tb[NET_SHAPER_A_HANDLE_ID];
433 	if (id_attr)
434 		id = nla_get_u32(id_attr);
435 	else if (handle->scope == NET_SHAPER_SCOPE_NODE)
436 		id = NET_SHAPER_ID_UNSPEC;
437 
438 	handle->id = id;
439 	return 0;
440 }
441 
442 static int net_shaper_validate_caps(struct net_shaper_binding *binding,
443 				    struct nlattr **tb,
444 				    const struct genl_info *info,
445 				    struct net_shaper *shaper)
446 {
447 	const struct net_shaper_ops *ops = net_shaper_ops(binding);
448 	struct nlattr *bad = NULL;
449 	unsigned long caps = 0;
450 
451 	ops->capabilities(binding, shaper->handle.scope, &caps);
452 
453 	if (tb[NET_SHAPER_A_PRIORITY] &&
454 	    !(caps & BIT(NET_SHAPER_A_CAPS_SUPPORT_PRIORITY)))
455 		bad = tb[NET_SHAPER_A_PRIORITY];
456 	if (tb[NET_SHAPER_A_WEIGHT] &&
457 	    !(caps & BIT(NET_SHAPER_A_CAPS_SUPPORT_WEIGHT)))
458 		bad = tb[NET_SHAPER_A_WEIGHT];
459 	if (tb[NET_SHAPER_A_BW_MIN] &&
460 	    !(caps & BIT(NET_SHAPER_A_CAPS_SUPPORT_BW_MIN)))
461 		bad = tb[NET_SHAPER_A_BW_MIN];
462 	if (tb[NET_SHAPER_A_BW_MAX] &&
463 	    !(caps & BIT(NET_SHAPER_A_CAPS_SUPPORT_BW_MAX)))
464 		bad = tb[NET_SHAPER_A_BW_MAX];
465 	if (tb[NET_SHAPER_A_BURST] &&
466 	    !(caps & BIT(NET_SHAPER_A_CAPS_SUPPORT_BURST)))
467 		bad = tb[NET_SHAPER_A_BURST];
468 
469 	if (!caps)
470 		bad = tb[NET_SHAPER_A_HANDLE];
471 
472 	if (bad) {
473 		NL_SET_BAD_ATTR(info->extack, bad);
474 		return -EOPNOTSUPP;
475 	}
476 
477 	if (shaper->handle.scope == NET_SHAPER_SCOPE_QUEUE &&
478 	    binding->type == NET_SHAPER_BINDING_TYPE_NETDEV &&
479 	    shaper->handle.id >= binding->netdev->real_num_tx_queues) {
480 		NL_SET_ERR_MSG_FMT(info->extack,
481 				   "Not existing queue id %d max %d",
482 				   shaper->handle.id,
483 				   binding->netdev->real_num_tx_queues);
484 		return -ENOENT;
485 	}
486 
487 	/* The metric is really used only if there is *any* rate-related
488 	 * setting, either in current attributes set or in pre-existing
489 	 * values.
490 	 */
491 	if (shaper->burst || shaper->bw_min || shaper->bw_max) {
492 		u32 metric_cap = NET_SHAPER_A_CAPS_SUPPORT_METRIC_BPS +
493 				 shaper->metric;
494 
495 		/* The metric test can fail even when the user did not
496 		 * specify the METRIC attribute. Pointing to rate related
497 		 * attribute will be confusing, as the attribute itself
498 		 * could be indeed supported, with a different metric.
499 		 * Be more specific.
500 		 */
501 		if (!(caps & BIT(metric_cap))) {
502 			NL_SET_ERR_MSG_FMT(info->extack, "Bad metric %d",
503 					   shaper->metric);
504 			return -EOPNOTSUPP;
505 		}
506 	}
507 	return 0;
508 }
509 
510 static int net_shaper_parse_info(struct net_shaper_binding *binding,
511 				 struct nlattr **tb,
512 				 const struct genl_info *info,
513 				 struct net_shaper *shaper,
514 				 bool *exists)
515 {
516 	struct net_shaper *old;
517 	int ret;
518 
519 	/* The shaper handle is the only mandatory attribute. */
520 	if (NL_REQ_ATTR_CHECK(info->extack, NULL, tb, NET_SHAPER_A_HANDLE))
521 		return -EINVAL;
522 
523 	ret = net_shaper_parse_handle(tb[NET_SHAPER_A_HANDLE], info,
524 				      &shaper->handle);
525 	if (ret)
526 		return ret;
527 
528 	if (shaper->handle.scope == NET_SHAPER_SCOPE_UNSPEC) {
529 		NL_SET_BAD_ATTR(info->extack, tb[NET_SHAPER_A_HANDLE]);
530 		return -EINVAL;
531 	}
532 
533 	/* Fetch existing hierarchy, if any, so that user provide info will
534 	 * incrementally update the existing shaper configuration.
535 	 */
536 	old = net_shaper_lookup(binding, &shaper->handle);
537 	if (old)
538 		*shaper = *old;
539 	*exists = !!old;
540 
541 	if (tb[NET_SHAPER_A_METRIC])
542 		shaper->metric = nla_get_u32(tb[NET_SHAPER_A_METRIC]);
543 
544 	if (tb[NET_SHAPER_A_BW_MIN])
545 		shaper->bw_min = nla_get_uint(tb[NET_SHAPER_A_BW_MIN]);
546 
547 	if (tb[NET_SHAPER_A_BW_MAX])
548 		shaper->bw_max = nla_get_uint(tb[NET_SHAPER_A_BW_MAX]);
549 
550 	if (tb[NET_SHAPER_A_BURST])
551 		shaper->burst = nla_get_uint(tb[NET_SHAPER_A_BURST]);
552 
553 	if (tb[NET_SHAPER_A_PRIORITY])
554 		shaper->priority = nla_get_u32(tb[NET_SHAPER_A_PRIORITY]);
555 
556 	if (tb[NET_SHAPER_A_WEIGHT])
557 		shaper->weight = nla_get_u32(tb[NET_SHAPER_A_WEIGHT]);
558 
559 	ret = net_shaper_validate_caps(binding, tb, info, shaper);
560 	if (ret < 0)
561 		return ret;
562 
563 	return 0;
564 }
565 
566 static int net_shaper_validate_nesting(struct net_shaper_binding *binding,
567 				       const struct net_shaper *shaper,
568 				       struct netlink_ext_ack *extack)
569 {
570 	const struct net_shaper_ops *ops = net_shaper_ops(binding);
571 	unsigned long caps = 0;
572 
573 	ops->capabilities(binding, shaper->handle.scope, &caps);
574 	if (!(caps & BIT(NET_SHAPER_A_CAPS_SUPPORT_NESTING))) {
575 		NL_SET_ERR_MSG_FMT(extack,
576 				   "Nesting not supported for scope %d",
577 				   shaper->handle.scope);
578 		return -EOPNOTSUPP;
579 	}
580 	return 0;
581 }
582 
583 /* Fetch the existing leaf and update it with the user-provided
584  * attributes.
585  */
586 static int net_shaper_parse_leaf(struct net_shaper_binding *binding,
587 				 const struct nlattr *attr,
588 				 const struct genl_info *info,
589 				 const struct net_shaper *node,
590 				 struct net_shaper *shaper)
591 {
592 	struct nlattr *tb[NET_SHAPER_A_WEIGHT + 1];
593 	bool exists;
594 	int ret;
595 
596 	ret = nla_parse_nested(tb, NET_SHAPER_A_WEIGHT, attr,
597 			       net_shaper_leaf_info_nl_policy, info->extack);
598 	if (ret < 0)
599 		return ret;
600 
601 	ret = net_shaper_parse_info(binding, tb, info, shaper, &exists);
602 	if (ret < 0)
603 		return ret;
604 
605 	if (shaper->handle.scope != NET_SHAPER_SCOPE_QUEUE) {
606 		NL_SET_BAD_ATTR(info->extack, tb[NET_SHAPER_A_HANDLE]);
607 		return -EINVAL;
608 	}
609 
610 	if (node->handle.scope == NET_SHAPER_SCOPE_NODE) {
611 		ret = net_shaper_validate_nesting(binding, shaper,
612 						  info->extack);
613 		if (ret < 0)
614 			return ret;
615 	}
616 
617 	if (!exists)
618 		net_shaper_default_parent(&shaper->handle, &shaper->parent);
619 	return 0;
620 }
621 
622 /* Alike net_parse_shaper_info(), but additionally allow the user specifying
623  * the shaper's parent handle.
624  */
625 static int net_shaper_parse_node(struct net_shaper_binding *binding,
626 				 struct nlattr **tb,
627 				 const struct genl_info *info,
628 				 struct net_shaper *shaper)
629 {
630 	bool exists;
631 	int ret;
632 
633 	ret = net_shaper_parse_info(binding, tb, info, shaper, &exists);
634 	if (ret)
635 		return ret;
636 
637 	if (shaper->handle.scope != NET_SHAPER_SCOPE_NODE &&
638 	    shaper->handle.scope != NET_SHAPER_SCOPE_NETDEV) {
639 		NL_SET_BAD_ATTR(info->extack, tb[NET_SHAPER_A_HANDLE]);
640 		return -EINVAL;
641 	}
642 
643 	if (tb[NET_SHAPER_A_PARENT]) {
644 		ret = net_shaper_parse_handle(tb[NET_SHAPER_A_PARENT], info,
645 					      &shaper->parent);
646 		if (ret)
647 			return ret;
648 
649 		if (shaper->parent.scope != NET_SHAPER_SCOPE_NODE &&
650 		    shaper->parent.scope != NET_SHAPER_SCOPE_NETDEV) {
651 			NL_SET_BAD_ATTR(info->extack, tb[NET_SHAPER_A_PARENT]);
652 			return -EINVAL;
653 		}
654 	}
655 	return 0;
656 }
657 
658 static int net_shaper_generic_pre(struct genl_info *info, int type)
659 {
660 	struct net_shaper_nl_ctx *ctx = (struct net_shaper_nl_ctx *)info->ctx;
661 
662 	BUILD_BUG_ON(sizeof(*ctx) > sizeof(info->ctx));
663 
664 	return net_shaper_ctx_setup(info, type, ctx);
665 }
666 
667 int net_shaper_nl_pre_doit(const struct genl_split_ops *ops,
668 			   struct sk_buff *skb, struct genl_info *info)
669 {
670 	return net_shaper_generic_pre(info, NET_SHAPER_A_IFINDEX);
671 }
672 
673 static void net_shaper_generic_post(struct genl_info *info)
674 {
675 	net_shaper_ctx_cleanup((struct net_shaper_nl_ctx *)info->ctx);
676 }
677 
678 void net_shaper_nl_post_doit(const struct genl_split_ops *ops,
679 			     struct sk_buff *skb, struct genl_info *info)
680 {
681 	net_shaper_generic_post(info);
682 }
683 
684 int net_shaper_nl_pre_dumpit(struct netlink_callback *cb)
685 {
686 	struct net_shaper_nl_ctx *ctx = (struct net_shaper_nl_ctx *)cb->ctx;
687 	const struct genl_info *info = genl_info_dump(cb);
688 
689 	return net_shaper_ctx_setup(info, NET_SHAPER_A_IFINDEX, ctx);
690 }
691 
692 int net_shaper_nl_post_dumpit(struct netlink_callback *cb)
693 {
694 	net_shaper_ctx_cleanup((struct net_shaper_nl_ctx *)cb->ctx);
695 	return 0;
696 }
697 
698 int net_shaper_nl_cap_pre_doit(const struct genl_split_ops *ops,
699 			       struct sk_buff *skb, struct genl_info *info)
700 {
701 	return net_shaper_generic_pre(info, NET_SHAPER_A_CAPS_IFINDEX);
702 }
703 
704 void net_shaper_nl_cap_post_doit(const struct genl_split_ops *ops,
705 				 struct sk_buff *skb, struct genl_info *info)
706 {
707 	net_shaper_generic_post(info);
708 }
709 
710 int net_shaper_nl_cap_pre_dumpit(struct netlink_callback *cb)
711 {
712 	struct net_shaper_nl_ctx *ctx = (struct net_shaper_nl_ctx *)cb->ctx;
713 
714 	return net_shaper_ctx_setup(genl_info_dump(cb),
715 				    NET_SHAPER_A_CAPS_IFINDEX, ctx);
716 }
717 
718 int net_shaper_nl_cap_post_dumpit(struct netlink_callback *cb)
719 {
720 	struct net_shaper_nl_ctx *ctx = (struct net_shaper_nl_ctx *)cb->ctx;
721 
722 	net_shaper_ctx_cleanup(ctx);
723 	return 0;
724 }
725 
726 int net_shaper_nl_get_doit(struct sk_buff *skb, struct genl_info *info)
727 {
728 	struct net_shaper_binding *binding;
729 	struct net_shaper_handle handle;
730 	struct net_shaper *shaper;
731 	struct sk_buff *msg;
732 	int ret;
733 
734 	if (GENL_REQ_ATTR_CHECK(info, NET_SHAPER_A_HANDLE))
735 		return -EINVAL;
736 
737 	binding = net_shaper_binding_from_ctx(info->ctx);
738 	ret = net_shaper_parse_handle(info->attrs[NET_SHAPER_A_HANDLE], info,
739 				      &handle);
740 	if (ret < 0)
741 		return ret;
742 
743 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
744 	if (!msg)
745 		return -ENOMEM;
746 
747 	rcu_read_lock();
748 	shaper = net_shaper_lookup(binding, &handle);
749 	if (!shaper) {
750 		NL_SET_BAD_ATTR(info->extack,
751 				info->attrs[NET_SHAPER_A_HANDLE]);
752 		rcu_read_unlock();
753 		ret = -ENOENT;
754 		goto free_msg;
755 	}
756 
757 	ret = net_shaper_fill_one(msg, binding, shaper, info);
758 	rcu_read_unlock();
759 	if (ret)
760 		goto free_msg;
761 
762 	ret = genlmsg_reply(msg, info);
763 	if (ret)
764 		goto free_msg;
765 
766 	return 0;
767 
768 free_msg:
769 	nlmsg_free(msg);
770 	return ret;
771 }
772 
773 int net_shaper_nl_get_dumpit(struct sk_buff *skb,
774 			     struct netlink_callback *cb)
775 {
776 	struct net_shaper_nl_ctx *ctx = (struct net_shaper_nl_ctx *)cb->ctx;
777 	const struct genl_info *info = genl_info_dump(cb);
778 	struct net_shaper_hierarchy *hierarchy;
779 	struct net_shaper_binding *binding;
780 	struct net_shaper *shaper;
781 	int ret = 0;
782 
783 	/* Don't error out dumps performed before any set operation. */
784 	binding = net_shaper_binding_from_ctx(ctx);
785 	hierarchy = net_shaper_hierarchy(binding);
786 	if (!hierarchy)
787 		return 0;
788 
789 	rcu_read_lock();
790 	for (; (shaper = xa_find(&hierarchy->shapers, &ctx->start_index,
791 				 U32_MAX, XA_PRESENT)); ctx->start_index++) {
792 		ret = net_shaper_fill_one(skb, binding, shaper, info);
793 		if (ret)
794 			break;
795 	}
796 	rcu_read_unlock();
797 
798 	return ret;
799 }
800 
801 int net_shaper_nl_set_doit(struct sk_buff *skb, struct genl_info *info)
802 {
803 	struct net_shaper_hierarchy *hierarchy;
804 	struct net_shaper_binding *binding;
805 	const struct net_shaper_ops *ops;
806 	struct net_shaper_handle handle;
807 	struct net_shaper shaper = {};
808 	bool exists;
809 	int ret;
810 
811 	binding = net_shaper_binding_from_ctx(info->ctx);
812 
813 	net_shaper_lock(binding);
814 	ret = net_shaper_parse_info(binding, info->attrs, info, &shaper,
815 				    &exists);
816 	if (ret)
817 		goto unlock;
818 
819 	if (!exists)
820 		net_shaper_default_parent(&shaper.handle, &shaper.parent);
821 
822 	hierarchy = net_shaper_hierarchy_setup(binding);
823 	if (!hierarchy) {
824 		ret = -ENOMEM;
825 		goto unlock;
826 	}
827 
828 	/* The 'set' operation can't create node-scope shapers. */
829 	handle = shaper.handle;
830 	if (handle.scope == NET_SHAPER_SCOPE_NODE &&
831 	    !net_shaper_lookup(binding, &handle)) {
832 		ret = -ENOENT;
833 		goto unlock;
834 	}
835 
836 	ret = net_shaper_pre_insert(binding, &handle, info->extack);
837 	if (ret)
838 		goto unlock;
839 
840 	ops = net_shaper_ops(binding);
841 	ret = ops->set(binding, &shaper, info->extack);
842 	if (ret) {
843 		net_shaper_rollback(binding);
844 		goto unlock;
845 	}
846 
847 	net_shaper_commit(binding, 1, &shaper);
848 
849 unlock:
850 	net_shaper_unlock(binding);
851 	return ret;
852 }
853 
854 static int __net_shaper_delete(struct net_shaper_binding *binding,
855 			       struct net_shaper *shaper,
856 			       struct netlink_ext_ack *extack)
857 {
858 	struct net_shaper_hierarchy *hierarchy = net_shaper_hierarchy(binding);
859 	struct net_shaper_handle parent_handle, handle = shaper->handle;
860 	const struct net_shaper_ops *ops = net_shaper_ops(binding);
861 	int ret;
862 
863 again:
864 	parent_handle = shaper->parent;
865 
866 	ret = ops->delete(binding, &handle, extack);
867 	if (ret < 0)
868 		return ret;
869 
870 	xa_erase(&hierarchy->shapers, net_shaper_handle_to_index(&handle));
871 	kfree_rcu(shaper, rcu);
872 
873 	/* Eventually delete the parent, if it is left over with no leaves. */
874 	if (parent_handle.scope == NET_SHAPER_SCOPE_NODE) {
875 		shaper = net_shaper_lookup(binding, &parent_handle);
876 		if (shaper && !--shaper->leaves) {
877 			handle = parent_handle;
878 			goto again;
879 		}
880 	}
881 	return 0;
882 }
883 
884 static int net_shaper_handle_cmp(const struct net_shaper_handle *a,
885 				 const struct net_shaper_handle *b)
886 {
887 	/* Must avoid holes in struct net_shaper_handle. */
888 	BUILD_BUG_ON(sizeof(*a) != 8);
889 
890 	return memcmp(a, b, sizeof(*a));
891 }
892 
893 static int net_shaper_parent_from_leaves(int leaves_count,
894 					 const struct net_shaper *leaves,
895 					 struct net_shaper *node,
896 					 struct netlink_ext_ack *extack)
897 {
898 	struct net_shaper_handle parent = leaves[0].parent;
899 	int i;
900 
901 	for (i = 1; i < leaves_count; ++i) {
902 		if (net_shaper_handle_cmp(&leaves[i].parent, &parent)) {
903 			NL_SET_ERR_MSG_FMT(extack, "All the leaves shapers must have the same old parent");
904 			return -EINVAL;
905 		}
906 	}
907 
908 	node->parent = parent;
909 	return 0;
910 }
911 
912 static int __net_shaper_group(struct net_shaper_binding *binding,
913 			      bool update_node, int leaves_count,
914 			      struct net_shaper *leaves,
915 			      struct net_shaper *node,
916 			      struct netlink_ext_ack *extack)
917 {
918 	const struct net_shaper_ops *ops = net_shaper_ops(binding);
919 	struct net_shaper_handle leaf_handle;
920 	struct net_shaper *parent = NULL;
921 	bool new_node = false;
922 	int i, ret;
923 
924 	if (node->handle.scope == NET_SHAPER_SCOPE_NODE) {
925 		new_node = node->handle.id == NET_SHAPER_ID_UNSPEC;
926 
927 		if (!new_node && !net_shaper_lookup(binding, &node->handle)) {
928 			/* The related attribute is not available when
929 			 * reaching here from the delete() op.
930 			 */
931 			NL_SET_ERR_MSG_FMT(extack, "Node shaper %d:%d does not exists",
932 					   node->handle.scope, node->handle.id);
933 			return -ENOENT;
934 		}
935 
936 		/* When unspecified, the node parent scope is inherited from
937 		 * the leaves.
938 		 */
939 		if (node->parent.scope == NET_SHAPER_SCOPE_UNSPEC) {
940 			ret = net_shaper_parent_from_leaves(leaves_count,
941 							    leaves, node,
942 							    extack);
943 			if (ret)
944 				return ret;
945 		}
946 
947 	} else {
948 		net_shaper_default_parent(&node->handle, &node->parent);
949 	}
950 
951 	if (node->parent.scope == NET_SHAPER_SCOPE_NODE) {
952 		parent = net_shaper_lookup(binding, &node->parent);
953 		if (!parent) {
954 			NL_SET_ERR_MSG_FMT(extack, "Node parent shaper %d:%d does not exists",
955 					   node->parent.scope, node->parent.id);
956 			return -ENOENT;
957 		}
958 
959 		ret = net_shaper_validate_nesting(binding, node, extack);
960 		if (ret < 0)
961 			return ret;
962 	}
963 
964 	if (update_node) {
965 		/* For newly created node scope shaper, the following will
966 		 * update the handle, due to id allocation.
967 		 */
968 		ret = net_shaper_pre_insert(binding, &node->handle, extack);
969 		if (ret)
970 			return ret;
971 	}
972 
973 	for (i = 0; i < leaves_count; ++i) {
974 		leaf_handle = leaves[i].handle;
975 
976 		ret = net_shaper_pre_insert(binding, &leaf_handle, extack);
977 		if (ret)
978 			goto rollback;
979 
980 		if (!net_shaper_handle_cmp(&leaves[i].parent, &node->handle))
981 			continue;
982 
983 		/* The leaves shapers will be nested to the node, update the
984 		 * linking accordingly.
985 		 */
986 		leaves[i].parent = node->handle;
987 		node->leaves++;
988 	}
989 
990 	ret = ops->group(binding, leaves_count, leaves, node, extack);
991 	if (ret < 0)
992 		goto rollback;
993 
994 	/* The node's parent gains a new leaf only when the node itself
995 	 * is created by this group operation
996 	 */
997 	if (new_node && parent)
998 		parent->leaves++;
999 	if (update_node)
1000 		net_shaper_commit(binding, 1, node);
1001 	net_shaper_commit(binding, leaves_count, leaves);
1002 	return 0;
1003 
1004 rollback:
1005 	net_shaper_rollback(binding);
1006 	return ret;
1007 }
1008 
1009 static int net_shaper_pre_del_node(struct net_shaper_binding *binding,
1010 				   const struct net_shaper *shaper,
1011 				   struct netlink_ext_ack *extack)
1012 {
1013 	struct net_shaper_hierarchy *hierarchy = net_shaper_hierarchy(binding);
1014 	struct net_shaper *cur, *leaves, node = {};
1015 	int ret, leaves_count = 0;
1016 	unsigned long index;
1017 	bool update_node;
1018 
1019 	if (!shaper->leaves)
1020 		return 0;
1021 
1022 	/* Fetch the new node information. */
1023 	node.handle = shaper->parent;
1024 	cur = net_shaper_lookup(binding, &node.handle);
1025 	if (cur) {
1026 		node = *cur;
1027 	} else {
1028 		/* A scope NODE shaper can be nested only to the NETDEV scope
1029 		 * shaper without creating the latter, this check may fail only
1030 		 * if the data is in inconsistent status.
1031 		 */
1032 		if (WARN_ON_ONCE(node.handle.scope != NET_SHAPER_SCOPE_NETDEV))
1033 			return -EINVAL;
1034 	}
1035 
1036 	leaves = kcalloc(shaper->leaves, sizeof(struct net_shaper),
1037 			 GFP_KERNEL);
1038 	if (!leaves)
1039 		return -ENOMEM;
1040 
1041 	/* Build the leaves arrays. */
1042 	xa_for_each(&hierarchy->shapers, index, cur) {
1043 		if (net_shaper_handle_cmp(&cur->parent, &shaper->handle))
1044 			continue;
1045 
1046 		if (WARN_ON_ONCE(leaves_count == shaper->leaves)) {
1047 			ret = -EINVAL;
1048 			goto free;
1049 		}
1050 
1051 		leaves[leaves_count++] = *cur;
1052 	}
1053 
1054 	/* When re-linking to the netdev shaper, avoid the eventual, implicit,
1055 	 * creation of the new node, would be surprising since the user is
1056 	 * doing a delete operation.
1057 	 */
1058 	update_node = node.handle.scope != NET_SHAPER_SCOPE_NETDEV;
1059 	ret = __net_shaper_group(binding, update_node, leaves_count,
1060 				 leaves, &node, extack);
1061 
1062 free:
1063 	kfree(leaves);
1064 	return ret;
1065 }
1066 
1067 int net_shaper_nl_delete_doit(struct sk_buff *skb, struct genl_info *info)
1068 {
1069 	struct net_shaper_hierarchy *hierarchy;
1070 	struct net_shaper_binding *binding;
1071 	struct net_shaper_handle handle;
1072 	struct net_shaper *shaper;
1073 	int ret;
1074 
1075 	if (GENL_REQ_ATTR_CHECK(info, NET_SHAPER_A_HANDLE))
1076 		return -EINVAL;
1077 
1078 	binding = net_shaper_binding_from_ctx(info->ctx);
1079 
1080 	net_shaper_lock(binding);
1081 	ret = net_shaper_parse_handle(info->attrs[NET_SHAPER_A_HANDLE], info,
1082 				      &handle);
1083 	if (ret)
1084 		goto unlock;
1085 
1086 	hierarchy = net_shaper_hierarchy(binding);
1087 	if (!hierarchy) {
1088 		ret = -ENOENT;
1089 		goto unlock;
1090 	}
1091 
1092 	shaper = net_shaper_lookup(binding, &handle);
1093 	if (!shaper) {
1094 		ret = -ENOENT;
1095 		goto unlock;
1096 	}
1097 
1098 	if (handle.scope == NET_SHAPER_SCOPE_NODE) {
1099 		ret = net_shaper_pre_del_node(binding, shaper, info->extack);
1100 		if (ret)
1101 			goto unlock;
1102 	}
1103 
1104 	ret = __net_shaper_delete(binding, shaper, info->extack);
1105 
1106 unlock:
1107 	net_shaper_unlock(binding);
1108 	return ret;
1109 }
1110 
1111 static int net_shaper_group_send_reply(struct net_shaper_binding *binding,
1112 				       const struct net_shaper_handle *handle,
1113 				       struct genl_info *info,
1114 				       struct sk_buff *msg)
1115 {
1116 	void *hdr;
1117 
1118 	hdr = genlmsg_iput(msg, info);
1119 	if (!hdr)
1120 		goto free_msg;
1121 
1122 	if (net_shaper_fill_binding(msg, binding, NET_SHAPER_A_IFINDEX) ||
1123 	    net_shaper_fill_handle(msg, handle, NET_SHAPER_A_HANDLE))
1124 		goto free_msg;
1125 
1126 	genlmsg_end(msg, hdr);
1127 
1128 	return genlmsg_reply(msg, info);
1129 
1130 free_msg:
1131 	/* Should never happen as msg is pre-allocated with enough space. */
1132 	WARN_ONCE(true, "calculated message payload length (%d)",
1133 		  net_shaper_handle_size());
1134 	nlmsg_free(msg);
1135 	return -EMSGSIZE;
1136 }
1137 
1138 int net_shaper_nl_group_doit(struct sk_buff *skb, struct genl_info *info)
1139 {
1140 	struct net_shaper **old_nodes, *leaves, node = {};
1141 	struct net_shaper_hierarchy *hierarchy;
1142 	struct net_shaper_binding *binding;
1143 	int i, ret, rem, leaves_count;
1144 	int old_nodes_count = 0;
1145 	struct sk_buff *msg;
1146 	struct nlattr *attr;
1147 
1148 	if (GENL_REQ_ATTR_CHECK(info, NET_SHAPER_A_LEAVES))
1149 		return -EINVAL;
1150 
1151 	binding = net_shaper_binding_from_ctx(info->ctx);
1152 
1153 	/* The group operation is optional. */
1154 	if (!net_shaper_ops(binding)->group)
1155 		return -EOPNOTSUPP;
1156 
1157 	net_shaper_lock(binding);
1158 	leaves_count = net_shaper_list_len(info, NET_SHAPER_A_LEAVES);
1159 	if (!leaves_count) {
1160 		NL_SET_BAD_ATTR(info->extack,
1161 				info->attrs[NET_SHAPER_A_LEAVES]);
1162 		ret = -EINVAL;
1163 		goto unlock;
1164 	}
1165 
1166 	leaves = kcalloc(leaves_count, sizeof(struct net_shaper) +
1167 			 sizeof(struct net_shaper *), GFP_KERNEL);
1168 	if (!leaves) {
1169 		ret = -ENOMEM;
1170 		goto unlock;
1171 	}
1172 	old_nodes = (void *)&leaves[leaves_count];
1173 
1174 	ret = net_shaper_parse_node(binding, info->attrs, info, &node);
1175 	if (ret)
1176 		goto free_leaves;
1177 
1178 	i = 0;
1179 	nla_for_each_attr_type(attr, NET_SHAPER_A_LEAVES,
1180 			       genlmsg_data(info->genlhdr),
1181 			       genlmsg_len(info->genlhdr), rem) {
1182 		if (WARN_ON_ONCE(i >= leaves_count))
1183 			goto free_leaves;
1184 
1185 		ret = net_shaper_parse_leaf(binding, attr, info,
1186 					    &node, &leaves[i]);
1187 		if (ret)
1188 			goto free_leaves;
1189 		i++;
1190 	}
1191 
1192 	/* Prepare the msg reply in advance, to avoid device operation
1193 	 * rollback on allocation failure.
1194 	 */
1195 	msg = genlmsg_new(net_shaper_handle_size(), GFP_KERNEL);
1196 	if (!msg)
1197 		goto free_leaves;
1198 
1199 	hierarchy = net_shaper_hierarchy_setup(binding);
1200 	if (!hierarchy) {
1201 		ret = -ENOMEM;
1202 		goto free_msg;
1203 	}
1204 
1205 	/* Record the node shapers that this group() operation can make
1206 	 * childless for later cleanup.
1207 	 */
1208 	for (i = 0; i < leaves_count; i++) {
1209 		if (leaves[i].parent.scope == NET_SHAPER_SCOPE_NODE &&
1210 		    net_shaper_handle_cmp(&leaves[i].parent, &node.handle)) {
1211 			struct net_shaper *tmp;
1212 
1213 			tmp = net_shaper_lookup(binding, &leaves[i].parent);
1214 			if (!tmp)
1215 				continue;
1216 
1217 			old_nodes[old_nodes_count++] = tmp;
1218 		}
1219 	}
1220 
1221 	ret = __net_shaper_group(binding, true, leaves_count, leaves, &node,
1222 				 info->extack);
1223 	if (ret)
1224 		goto free_msg;
1225 
1226 	/* Check if we need to delete any node left alone by the new leaves
1227 	 * linkage.
1228 	 */
1229 	for (i = 0; i < old_nodes_count; ++i) {
1230 		struct net_shaper *tmp = old_nodes[i];
1231 
1232 		if (--tmp->leaves > 0)
1233 			continue;
1234 
1235 		/* Errors here are not fatal: the grouping operation is
1236 		 * completed, and user-space can still explicitly clean-up
1237 		 * left-over nodes.
1238 		 */
1239 		__net_shaper_delete(binding, tmp, info->extack);
1240 	}
1241 
1242 	ret = net_shaper_group_send_reply(binding, &node.handle, info, msg);
1243 	if (ret)
1244 		GENL_SET_ERR_MSG_FMT(info, "Can't send reply");
1245 
1246 free_leaves:
1247 	kfree(leaves);
1248 
1249 unlock:
1250 	net_shaper_unlock(binding);
1251 	return ret;
1252 
1253 free_msg:
1254 	kfree_skb(msg);
1255 	goto free_leaves;
1256 }
1257 
1258 static int
1259 net_shaper_cap_fill_one(struct sk_buff *msg,
1260 			struct net_shaper_binding *binding,
1261 			enum net_shaper_scope scope, unsigned long flags,
1262 			const struct genl_info *info)
1263 {
1264 	unsigned long cur;
1265 	void *hdr;
1266 
1267 	hdr = genlmsg_iput(msg, info);
1268 	if (!hdr)
1269 		return -EMSGSIZE;
1270 
1271 	if (net_shaper_fill_binding(msg, binding, NET_SHAPER_A_CAPS_IFINDEX) ||
1272 	    nla_put_u32(msg, NET_SHAPER_A_CAPS_SCOPE, scope))
1273 		goto nla_put_failure;
1274 
1275 	for (cur = NET_SHAPER_A_CAPS_SUPPORT_METRIC_BPS;
1276 	     cur <= NET_SHAPER_A_CAPS_MAX; ++cur) {
1277 		if (flags & BIT(cur) && nla_put_flag(msg, cur))
1278 			goto nla_put_failure;
1279 	}
1280 
1281 	genlmsg_end(msg, hdr);
1282 
1283 	return 0;
1284 
1285 nla_put_failure:
1286 	genlmsg_cancel(msg, hdr);
1287 	return -EMSGSIZE;
1288 }
1289 
1290 int net_shaper_nl_cap_get_doit(struct sk_buff *skb, struct genl_info *info)
1291 {
1292 	struct net_shaper_binding *binding;
1293 	const struct net_shaper_ops *ops;
1294 	enum net_shaper_scope scope;
1295 	unsigned long flags = 0;
1296 	struct sk_buff *msg;
1297 	int ret;
1298 
1299 	if (GENL_REQ_ATTR_CHECK(info, NET_SHAPER_A_CAPS_SCOPE))
1300 		return -EINVAL;
1301 
1302 	binding = net_shaper_binding_from_ctx(info->ctx);
1303 	scope = nla_get_u32(info->attrs[NET_SHAPER_A_CAPS_SCOPE]);
1304 	ops = net_shaper_ops(binding);
1305 	ops->capabilities(binding, scope, &flags);
1306 	if (!flags)
1307 		return -EOPNOTSUPP;
1308 
1309 	msg = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1310 	if (!msg)
1311 		return -ENOMEM;
1312 
1313 	ret = net_shaper_cap_fill_one(msg, binding, scope, flags, info);
1314 	if (ret)
1315 		goto free_msg;
1316 
1317 	ret =  genlmsg_reply(msg, info);
1318 	if (ret)
1319 		goto free_msg;
1320 	return 0;
1321 
1322 free_msg:
1323 	nlmsg_free(msg);
1324 	return ret;
1325 }
1326 
1327 int net_shaper_nl_cap_get_dumpit(struct sk_buff *skb,
1328 				 struct netlink_callback *cb)
1329 {
1330 	const struct genl_info *info = genl_info_dump(cb);
1331 	struct net_shaper_binding *binding;
1332 	const struct net_shaper_ops *ops;
1333 	enum net_shaper_scope scope;
1334 	int ret;
1335 
1336 	binding = net_shaper_binding_from_ctx(cb->ctx);
1337 	ops = net_shaper_ops(binding);
1338 	for (scope = 0; scope <= NET_SHAPER_SCOPE_MAX; ++scope) {
1339 		unsigned long flags = 0;
1340 
1341 		ops->capabilities(binding, scope, &flags);
1342 		if (!flags)
1343 			continue;
1344 
1345 		ret = net_shaper_cap_fill_one(skb, binding, scope, flags,
1346 					      info);
1347 		if (ret)
1348 			return ret;
1349 	}
1350 
1351 	return 0;
1352 }
1353 
1354 static void net_shaper_flush(struct net_shaper_binding *binding)
1355 {
1356 	struct net_shaper_hierarchy *hierarchy = net_shaper_hierarchy(binding);
1357 	struct net_shaper *cur;
1358 	unsigned long index;
1359 
1360 	if (!hierarchy)
1361 		return;
1362 
1363 	net_shaper_lock(binding);
1364 	xa_lock(&hierarchy->shapers);
1365 	xa_for_each(&hierarchy->shapers, index, cur) {
1366 		__xa_erase(&hierarchy->shapers, index);
1367 		kfree(cur);
1368 	}
1369 	xa_unlock(&hierarchy->shapers);
1370 	net_shaper_unlock(binding);
1371 
1372 	kfree(hierarchy);
1373 }
1374 
1375 void net_shaper_flush_netdev(struct net_device *dev)
1376 {
1377 	struct net_shaper_binding binding = {
1378 		.type = NET_SHAPER_BINDING_TYPE_NETDEV,
1379 		.netdev = dev,
1380 	};
1381 
1382 	net_shaper_flush(&binding);
1383 }
1384 
1385 void net_shaper_set_real_num_tx_queues(struct net_device *dev,
1386 				       unsigned int txq)
1387 {
1388 	struct net_shaper_hierarchy *hierarchy;
1389 	struct net_shaper_binding binding;
1390 	int i;
1391 
1392 	binding.type = NET_SHAPER_BINDING_TYPE_NETDEV;
1393 	binding.netdev = dev;
1394 	hierarchy = net_shaper_hierarchy(&binding);
1395 	if (!hierarchy)
1396 		return;
1397 
1398 	/* Only drivers implementing shapers support ensure
1399 	 * the lock is acquired in advance.
1400 	 */
1401 	lockdep_assert_held(&dev->lock);
1402 
1403 	/* Take action only when decreasing the tx queue number. */
1404 	for (i = txq; i < dev->real_num_tx_queues; ++i) {
1405 		struct net_shaper_handle handle, parent_handle;
1406 		struct net_shaper *shaper;
1407 		u32 index;
1408 
1409 		handle.scope = NET_SHAPER_SCOPE_QUEUE;
1410 		handle.id = i;
1411 		shaper = net_shaper_lookup(&binding, &handle);
1412 		if (!shaper)
1413 			continue;
1414 
1415 		/* Don't touch the H/W for the queue shaper, the drivers already
1416 		 * deleted the queue and related resources.
1417 		 */
1418 		parent_handle = shaper->parent;
1419 		index = net_shaper_handle_to_index(&handle);
1420 		xa_erase(&hierarchy->shapers, index);
1421 		kfree_rcu(shaper, rcu);
1422 
1423 		/* The recursion on parent does the full job. */
1424 		if (parent_handle.scope != NET_SHAPER_SCOPE_NODE)
1425 			continue;
1426 
1427 		shaper = net_shaper_lookup(&binding, &parent_handle);
1428 		if (shaper && !--shaper->leaves)
1429 			__net_shaper_delete(&binding, shaper, NULL);
1430 	}
1431 }
1432 
1433 static int __init shaper_init(void)
1434 {
1435 	return genl_register_family(&net_shaper_nl_family);
1436 }
1437 
1438 subsys_initcall(shaper_init);
1439