xref: /linux/net/core/netdev-genl.c (revision f898c16a0624e7f2dcb0b1cda6916c9be6489197)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <linux/netdevice.h>
4 #include <linux/notifier.h>
5 #include <linux/rtnetlink.h>
6 #include <net/net_namespace.h>
7 #include <net/sock.h>
8 #include <net/xdp.h>
9 #include <net/xdp_sock.h>
10 #include <net/netdev_rx_queue.h>
11 #include <net/netdev_queues.h>
12 #include <net/busy_poll.h>
13 
14 #include "netdev-genl-gen.h"
15 #include "dev.h"
16 
17 struct netdev_nl_dump_ctx {
18 	unsigned long	ifindex;
19 	unsigned int	rxq_idx;
20 	unsigned int	txq_idx;
21 	unsigned int	napi_id;
22 };
23 
24 static struct netdev_nl_dump_ctx *netdev_dump_ctx(struct netlink_callback *cb)
25 {
26 	NL_ASSERT_DUMP_CTX_FITS(struct netdev_nl_dump_ctx);
27 
28 	return (struct netdev_nl_dump_ctx *)cb->ctx;
29 }
30 
31 static int
32 netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp,
33 		   const struct genl_info *info)
34 {
35 	u64 xsk_features = 0;
36 	u64 xdp_rx_meta = 0;
37 	void *hdr;
38 
39 	hdr = genlmsg_iput(rsp, info);
40 	if (!hdr)
41 		return -EMSGSIZE;
42 
43 #define XDP_METADATA_KFUNC(_, flag, __, xmo) \
44 	if (netdev->xdp_metadata_ops && netdev->xdp_metadata_ops->xmo) \
45 		xdp_rx_meta |= flag;
46 XDP_METADATA_KFUNC_xxx
47 #undef XDP_METADATA_KFUNC
48 
49 	if (netdev->xsk_tx_metadata_ops) {
50 		if (netdev->xsk_tx_metadata_ops->tmo_fill_timestamp)
51 			xsk_features |= NETDEV_XSK_FLAGS_TX_TIMESTAMP;
52 		if (netdev->xsk_tx_metadata_ops->tmo_request_checksum)
53 			xsk_features |= NETDEV_XSK_FLAGS_TX_CHECKSUM;
54 	}
55 
56 	if (nla_put_u32(rsp, NETDEV_A_DEV_IFINDEX, netdev->ifindex) ||
57 	    nla_put_u64_64bit(rsp, NETDEV_A_DEV_XDP_FEATURES,
58 			      netdev->xdp_features, NETDEV_A_DEV_PAD) ||
59 	    nla_put_u64_64bit(rsp, NETDEV_A_DEV_XDP_RX_METADATA_FEATURES,
60 			      xdp_rx_meta, NETDEV_A_DEV_PAD) ||
61 	    nla_put_u64_64bit(rsp, NETDEV_A_DEV_XSK_FEATURES,
62 			      xsk_features, NETDEV_A_DEV_PAD))
63 		goto err_cancel_msg;
64 
65 	if (netdev->xdp_features & NETDEV_XDP_ACT_XSK_ZEROCOPY) {
66 		if (nla_put_u32(rsp, NETDEV_A_DEV_XDP_ZC_MAX_SEGS,
67 				netdev->xdp_zc_max_segs))
68 			goto err_cancel_msg;
69 	}
70 
71 	genlmsg_end(rsp, hdr);
72 
73 	return 0;
74 
75 err_cancel_msg:
76 	genlmsg_cancel(rsp, hdr);
77 	return -EMSGSIZE;
78 }
79 
80 static void
81 netdev_genl_dev_notify(struct net_device *netdev, int cmd)
82 {
83 	struct genl_info info;
84 	struct sk_buff *ntf;
85 
86 	if (!genl_has_listeners(&netdev_nl_family, dev_net(netdev),
87 				NETDEV_NLGRP_MGMT))
88 		return;
89 
90 	genl_info_init_ntf(&info, &netdev_nl_family, cmd);
91 
92 	ntf = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
93 	if (!ntf)
94 		return;
95 
96 	if (netdev_nl_dev_fill(netdev, ntf, &info)) {
97 		nlmsg_free(ntf);
98 		return;
99 	}
100 
101 	genlmsg_multicast_netns(&netdev_nl_family, dev_net(netdev), ntf,
102 				0, NETDEV_NLGRP_MGMT, GFP_KERNEL);
103 }
104 
105 int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info)
106 {
107 	struct net_device *netdev;
108 	struct sk_buff *rsp;
109 	u32 ifindex;
110 	int err;
111 
112 	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_DEV_IFINDEX))
113 		return -EINVAL;
114 
115 	ifindex = nla_get_u32(info->attrs[NETDEV_A_DEV_IFINDEX]);
116 
117 	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
118 	if (!rsp)
119 		return -ENOMEM;
120 
121 	rtnl_lock();
122 
123 	netdev = __dev_get_by_index(genl_info_net(info), ifindex);
124 	if (netdev)
125 		err = netdev_nl_dev_fill(netdev, rsp, info);
126 	else
127 		err = -ENODEV;
128 
129 	rtnl_unlock();
130 
131 	if (err)
132 		goto err_free_msg;
133 
134 	return genlmsg_reply(rsp, info);
135 
136 err_free_msg:
137 	nlmsg_free(rsp);
138 	return err;
139 }
140 
141 int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
142 {
143 	struct netdev_nl_dump_ctx *ctx = netdev_dump_ctx(cb);
144 	struct net *net = sock_net(skb->sk);
145 	struct net_device *netdev;
146 	int err = 0;
147 
148 	rtnl_lock();
149 	for_each_netdev_dump(net, netdev, ctx->ifindex) {
150 		err = netdev_nl_dev_fill(netdev, skb, genl_info_dump(cb));
151 		if (err < 0)
152 			break;
153 	}
154 	rtnl_unlock();
155 
156 	return err;
157 }
158 
159 static int
160 netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
161 			const struct genl_info *info)
162 {
163 	void *hdr;
164 	pid_t pid;
165 
166 	if (WARN_ON_ONCE(!napi->dev))
167 		return -EINVAL;
168 	if (!(napi->dev->flags & IFF_UP))
169 		return 0;
170 
171 	hdr = genlmsg_iput(rsp, info);
172 	if (!hdr)
173 		return -EMSGSIZE;
174 
175 	if (napi->napi_id >= MIN_NAPI_ID &&
176 	    nla_put_u32(rsp, NETDEV_A_NAPI_ID, napi->napi_id))
177 		goto nla_put_failure;
178 
179 	if (nla_put_u32(rsp, NETDEV_A_NAPI_IFINDEX, napi->dev->ifindex))
180 		goto nla_put_failure;
181 
182 	if (napi->irq >= 0 && nla_put_u32(rsp, NETDEV_A_NAPI_IRQ, napi->irq))
183 		goto nla_put_failure;
184 
185 	if (napi->thread) {
186 		pid = task_pid_nr(napi->thread);
187 		if (nla_put_u32(rsp, NETDEV_A_NAPI_PID, pid))
188 			goto nla_put_failure;
189 	}
190 
191 	genlmsg_end(rsp, hdr);
192 
193 	return 0;
194 
195 nla_put_failure:
196 	genlmsg_cancel(rsp, hdr);
197 	return -EMSGSIZE;
198 }
199 
200 int netdev_nl_napi_get_doit(struct sk_buff *skb, struct genl_info *info)
201 {
202 	struct napi_struct *napi;
203 	struct sk_buff *rsp;
204 	u32 napi_id;
205 	int err;
206 
207 	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_NAPI_ID))
208 		return -EINVAL;
209 
210 	napi_id = nla_get_u32(info->attrs[NETDEV_A_NAPI_ID]);
211 
212 	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
213 	if (!rsp)
214 		return -ENOMEM;
215 
216 	rtnl_lock();
217 
218 	napi = napi_by_id(napi_id);
219 	if (napi)
220 		err = netdev_nl_napi_fill_one(rsp, napi, info);
221 	else
222 		err = -EINVAL;
223 
224 	rtnl_unlock();
225 
226 	if (err)
227 		goto err_free_msg;
228 
229 	return genlmsg_reply(rsp, info);
230 
231 err_free_msg:
232 	nlmsg_free(rsp);
233 	return err;
234 }
235 
236 static int
237 netdev_nl_napi_dump_one(struct net_device *netdev, struct sk_buff *rsp,
238 			const struct genl_info *info,
239 			struct netdev_nl_dump_ctx *ctx)
240 {
241 	struct napi_struct *napi;
242 	int err = 0;
243 
244 	if (!(netdev->flags & IFF_UP))
245 		return err;
246 
247 	list_for_each_entry(napi, &netdev->napi_list, dev_list) {
248 		if (ctx->napi_id && napi->napi_id >= ctx->napi_id)
249 			continue;
250 
251 		err = netdev_nl_napi_fill_one(rsp, napi, info);
252 		if (err)
253 			return err;
254 		ctx->napi_id = napi->napi_id;
255 	}
256 	return err;
257 }
258 
259 int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
260 {
261 	struct netdev_nl_dump_ctx *ctx = netdev_dump_ctx(cb);
262 	const struct genl_info *info = genl_info_dump(cb);
263 	struct net *net = sock_net(skb->sk);
264 	struct net_device *netdev;
265 	u32 ifindex = 0;
266 	int err = 0;
267 
268 	if (info->attrs[NETDEV_A_NAPI_IFINDEX])
269 		ifindex = nla_get_u32(info->attrs[NETDEV_A_NAPI_IFINDEX]);
270 
271 	rtnl_lock();
272 	if (ifindex) {
273 		netdev = __dev_get_by_index(net, ifindex);
274 		if (netdev)
275 			err = netdev_nl_napi_dump_one(netdev, skb, info, ctx);
276 		else
277 			err = -ENODEV;
278 	} else {
279 		for_each_netdev_dump(net, netdev, ctx->ifindex) {
280 			err = netdev_nl_napi_dump_one(netdev, skb, info, ctx);
281 			if (err < 0)
282 				break;
283 			ctx->napi_id = 0;
284 		}
285 	}
286 	rtnl_unlock();
287 
288 	return err;
289 }
290 
291 static int
292 netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
293 			 u32 q_idx, u32 q_type, const struct genl_info *info)
294 {
295 	struct netdev_rx_queue *rxq;
296 	struct netdev_queue *txq;
297 	void *hdr;
298 
299 	hdr = genlmsg_iput(rsp, info);
300 	if (!hdr)
301 		return -EMSGSIZE;
302 
303 	if (nla_put_u32(rsp, NETDEV_A_QUEUE_ID, q_idx) ||
304 	    nla_put_u32(rsp, NETDEV_A_QUEUE_TYPE, q_type) ||
305 	    nla_put_u32(rsp, NETDEV_A_QUEUE_IFINDEX, netdev->ifindex))
306 		goto nla_put_failure;
307 
308 	switch (q_type) {
309 	case NETDEV_QUEUE_TYPE_RX:
310 		rxq = __netif_get_rx_queue(netdev, q_idx);
311 		if (rxq->napi && nla_put_u32(rsp, NETDEV_A_QUEUE_NAPI_ID,
312 					     rxq->napi->napi_id))
313 			goto nla_put_failure;
314 		break;
315 	case NETDEV_QUEUE_TYPE_TX:
316 		txq = netdev_get_tx_queue(netdev, q_idx);
317 		if (txq->napi && nla_put_u32(rsp, NETDEV_A_QUEUE_NAPI_ID,
318 					     txq->napi->napi_id))
319 			goto nla_put_failure;
320 	}
321 
322 	genlmsg_end(rsp, hdr);
323 
324 	return 0;
325 
326 nla_put_failure:
327 	genlmsg_cancel(rsp, hdr);
328 	return -EMSGSIZE;
329 }
330 
331 static int netdev_nl_queue_validate(struct net_device *netdev, u32 q_id,
332 				    u32 q_type)
333 {
334 	switch (q_type) {
335 	case NETDEV_QUEUE_TYPE_RX:
336 		if (q_id >= netdev->real_num_rx_queues)
337 			return -EINVAL;
338 		return 0;
339 	case NETDEV_QUEUE_TYPE_TX:
340 		if (q_id >= netdev->real_num_tx_queues)
341 			return -EINVAL;
342 	}
343 	return 0;
344 }
345 
346 static int
347 netdev_nl_queue_fill(struct sk_buff *rsp, struct net_device *netdev, u32 q_idx,
348 		     u32 q_type, const struct genl_info *info)
349 {
350 	int err = 0;
351 
352 	if (!(netdev->flags & IFF_UP))
353 		return err;
354 
355 	err = netdev_nl_queue_validate(netdev, q_idx, q_type);
356 	if (err)
357 		return err;
358 
359 	return netdev_nl_queue_fill_one(rsp, netdev, q_idx, q_type, info);
360 }
361 
362 int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info)
363 {
364 	u32 q_id, q_type, ifindex;
365 	struct net_device *netdev;
366 	struct sk_buff *rsp;
367 	int err;
368 
369 	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_ID) ||
370 	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_TYPE) ||
371 	    GENL_REQ_ATTR_CHECK(info, NETDEV_A_QUEUE_IFINDEX))
372 		return -EINVAL;
373 
374 	q_id = nla_get_u32(info->attrs[NETDEV_A_QUEUE_ID]);
375 	q_type = nla_get_u32(info->attrs[NETDEV_A_QUEUE_TYPE]);
376 	ifindex = nla_get_u32(info->attrs[NETDEV_A_QUEUE_IFINDEX]);
377 
378 	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
379 	if (!rsp)
380 		return -ENOMEM;
381 
382 	rtnl_lock();
383 
384 	netdev = __dev_get_by_index(genl_info_net(info), ifindex);
385 	if (netdev)
386 		err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);
387 	else
388 		err = -ENODEV;
389 
390 	rtnl_unlock();
391 
392 	if (err)
393 		goto err_free_msg;
394 
395 	return genlmsg_reply(rsp, info);
396 
397 err_free_msg:
398 	nlmsg_free(rsp);
399 	return err;
400 }
401 
402 static int
403 netdev_nl_queue_dump_one(struct net_device *netdev, struct sk_buff *rsp,
404 			 const struct genl_info *info,
405 			 struct netdev_nl_dump_ctx *ctx)
406 {
407 	int err = 0;
408 	int i;
409 
410 	if (!(netdev->flags & IFF_UP))
411 		return err;
412 
413 	for (i = ctx->rxq_idx; i < netdev->real_num_rx_queues;) {
414 		err = netdev_nl_queue_fill_one(rsp, netdev, i,
415 					       NETDEV_QUEUE_TYPE_RX, info);
416 		if (err)
417 			return err;
418 		ctx->rxq_idx = i++;
419 	}
420 	for (i = ctx->txq_idx; i < netdev->real_num_tx_queues;) {
421 		err = netdev_nl_queue_fill_one(rsp, netdev, i,
422 					       NETDEV_QUEUE_TYPE_TX, info);
423 		if (err)
424 			return err;
425 		ctx->txq_idx = i++;
426 	}
427 
428 	return err;
429 }
430 
431 int netdev_nl_queue_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
432 {
433 	struct netdev_nl_dump_ctx *ctx = netdev_dump_ctx(cb);
434 	const struct genl_info *info = genl_info_dump(cb);
435 	struct net *net = sock_net(skb->sk);
436 	struct net_device *netdev;
437 	u32 ifindex = 0;
438 	int err = 0;
439 
440 	if (info->attrs[NETDEV_A_QUEUE_IFINDEX])
441 		ifindex = nla_get_u32(info->attrs[NETDEV_A_QUEUE_IFINDEX]);
442 
443 	rtnl_lock();
444 	if (ifindex) {
445 		netdev = __dev_get_by_index(net, ifindex);
446 		if (netdev)
447 			err = netdev_nl_queue_dump_one(netdev, skb, info, ctx);
448 		else
449 			err = -ENODEV;
450 	} else {
451 		for_each_netdev_dump(net, netdev, ctx->ifindex) {
452 			err = netdev_nl_queue_dump_one(netdev, skb, info, ctx);
453 			if (err < 0)
454 				break;
455 			ctx->rxq_idx = 0;
456 			ctx->txq_idx = 0;
457 		}
458 	}
459 	rtnl_unlock();
460 
461 	return err;
462 }
463 
464 #define NETDEV_STAT_NOT_SET		(~0ULL)
465 
466 static void netdev_nl_stats_add(void *_sum, const void *_add, size_t size)
467 {
468 	const u64 *add = _add;
469 	u64 *sum = _sum;
470 
471 	while (size) {
472 		if (*add != NETDEV_STAT_NOT_SET && *sum != NETDEV_STAT_NOT_SET)
473 			*sum += *add;
474 		sum++;
475 		add++;
476 		size -= 8;
477 	}
478 }
479 
480 static int netdev_stat_put(struct sk_buff *rsp, unsigned int attr_id, u64 value)
481 {
482 	if (value == NETDEV_STAT_NOT_SET)
483 		return 0;
484 	return nla_put_uint(rsp, attr_id, value);
485 }
486 
487 static int
488 netdev_nl_stats_write_rx(struct sk_buff *rsp, struct netdev_queue_stats_rx *rx)
489 {
490 	if (netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_PACKETS, rx->packets) ||
491 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_BYTES, rx->bytes) ||
492 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_ALLOC_FAIL, rx->alloc_fail) ||
493 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_HW_DROPS, rx->hw_drops) ||
494 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_HW_DROP_OVERRUNS, rx->hw_drop_overruns) ||
495 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_CSUM_UNNECESSARY, rx->csum_unnecessary) ||
496 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_CSUM_NONE, rx->csum_none) ||
497 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_CSUM_BAD, rx->csum_bad) ||
498 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_HW_GRO_PACKETS, rx->hw_gro_packets) ||
499 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_HW_GRO_BYTES, rx->hw_gro_bytes) ||
500 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_HW_GRO_WIRE_PACKETS, rx->hw_gro_wire_packets) ||
501 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_HW_GRO_WIRE_BYTES, rx->hw_gro_wire_bytes) ||
502 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_HW_DROP_RATELIMITS, rx->hw_drop_ratelimits))
503 		return -EMSGSIZE;
504 	return 0;
505 }
506 
507 static int
508 netdev_nl_stats_write_tx(struct sk_buff *rsp, struct netdev_queue_stats_tx *tx)
509 {
510 	if (netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_PACKETS, tx->packets) ||
511 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_BYTES, tx->bytes) ||
512 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_DROPS, tx->hw_drops) ||
513 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_DROP_ERRORS, tx->hw_drop_errors) ||
514 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_CSUM_NONE, tx->csum_none) ||
515 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_NEEDS_CSUM, tx->needs_csum) ||
516 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_GSO_PACKETS, tx->hw_gso_packets) ||
517 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_GSO_BYTES, tx->hw_gso_bytes) ||
518 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_GSO_WIRE_PACKETS, tx->hw_gso_wire_packets) ||
519 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_GSO_WIRE_BYTES, tx->hw_gso_wire_bytes) ||
520 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_DROP_RATELIMITS, tx->hw_drop_ratelimits) ||
521 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_STOP, tx->stop) ||
522 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_WAKE, tx->wake))
523 		return -EMSGSIZE;
524 	return 0;
525 }
526 
527 static int
528 netdev_nl_stats_queue(struct net_device *netdev, struct sk_buff *rsp,
529 		      u32 q_type, int i, const struct genl_info *info)
530 {
531 	const struct netdev_stat_ops *ops = netdev->stat_ops;
532 	struct netdev_queue_stats_rx rx;
533 	struct netdev_queue_stats_tx tx;
534 	void *hdr;
535 
536 	hdr = genlmsg_iput(rsp, info);
537 	if (!hdr)
538 		return -EMSGSIZE;
539 	if (nla_put_u32(rsp, NETDEV_A_QSTATS_IFINDEX, netdev->ifindex) ||
540 	    nla_put_u32(rsp, NETDEV_A_QSTATS_QUEUE_TYPE, q_type) ||
541 	    nla_put_u32(rsp, NETDEV_A_QSTATS_QUEUE_ID, i))
542 		goto nla_put_failure;
543 
544 	switch (q_type) {
545 	case NETDEV_QUEUE_TYPE_RX:
546 		memset(&rx, 0xff, sizeof(rx));
547 		ops->get_queue_stats_rx(netdev, i, &rx);
548 		if (!memchr_inv(&rx, 0xff, sizeof(rx)))
549 			goto nla_cancel;
550 		if (netdev_nl_stats_write_rx(rsp, &rx))
551 			goto nla_put_failure;
552 		break;
553 	case NETDEV_QUEUE_TYPE_TX:
554 		memset(&tx, 0xff, sizeof(tx));
555 		ops->get_queue_stats_tx(netdev, i, &tx);
556 		if (!memchr_inv(&tx, 0xff, sizeof(tx)))
557 			goto nla_cancel;
558 		if (netdev_nl_stats_write_tx(rsp, &tx))
559 			goto nla_put_failure;
560 		break;
561 	}
562 
563 	genlmsg_end(rsp, hdr);
564 	return 0;
565 
566 nla_cancel:
567 	genlmsg_cancel(rsp, hdr);
568 	return 0;
569 nla_put_failure:
570 	genlmsg_cancel(rsp, hdr);
571 	return -EMSGSIZE;
572 }
573 
574 static int
575 netdev_nl_stats_by_queue(struct net_device *netdev, struct sk_buff *rsp,
576 			 const struct genl_info *info,
577 			 struct netdev_nl_dump_ctx *ctx)
578 {
579 	const struct netdev_stat_ops *ops = netdev->stat_ops;
580 	int i, err;
581 
582 	if (!(netdev->flags & IFF_UP))
583 		return 0;
584 
585 	i = ctx->rxq_idx;
586 	while (ops->get_queue_stats_rx && i < netdev->real_num_rx_queues) {
587 		err = netdev_nl_stats_queue(netdev, rsp, NETDEV_QUEUE_TYPE_RX,
588 					    i, info);
589 		if (err)
590 			return err;
591 		ctx->rxq_idx = i++;
592 	}
593 	i = ctx->txq_idx;
594 	while (ops->get_queue_stats_tx && i < netdev->real_num_tx_queues) {
595 		err = netdev_nl_stats_queue(netdev, rsp, NETDEV_QUEUE_TYPE_TX,
596 					    i, info);
597 		if (err)
598 			return err;
599 		ctx->txq_idx = i++;
600 	}
601 
602 	ctx->rxq_idx = 0;
603 	ctx->txq_idx = 0;
604 	return 0;
605 }
606 
607 static int
608 netdev_nl_stats_by_netdev(struct net_device *netdev, struct sk_buff *rsp,
609 			  const struct genl_info *info)
610 {
611 	struct netdev_queue_stats_rx rx_sum, rx;
612 	struct netdev_queue_stats_tx tx_sum, tx;
613 	const struct netdev_stat_ops *ops;
614 	void *hdr;
615 	int i;
616 
617 	ops = netdev->stat_ops;
618 	/* Netdev can't guarantee any complete counters */
619 	if (!ops->get_base_stats)
620 		return 0;
621 
622 	memset(&rx_sum, 0xff, sizeof(rx_sum));
623 	memset(&tx_sum, 0xff, sizeof(tx_sum));
624 
625 	ops->get_base_stats(netdev, &rx_sum, &tx_sum);
626 
627 	/* The op was there, but nothing reported, don't bother */
628 	if (!memchr_inv(&rx_sum, 0xff, sizeof(rx_sum)) &&
629 	    !memchr_inv(&tx_sum, 0xff, sizeof(tx_sum)))
630 		return 0;
631 
632 	hdr = genlmsg_iput(rsp, info);
633 	if (!hdr)
634 		return -EMSGSIZE;
635 	if (nla_put_u32(rsp, NETDEV_A_QSTATS_IFINDEX, netdev->ifindex))
636 		goto nla_put_failure;
637 
638 	for (i = 0; i < netdev->real_num_rx_queues; i++) {
639 		memset(&rx, 0xff, sizeof(rx));
640 		if (ops->get_queue_stats_rx)
641 			ops->get_queue_stats_rx(netdev, i, &rx);
642 		netdev_nl_stats_add(&rx_sum, &rx, sizeof(rx));
643 	}
644 	for (i = 0; i < netdev->real_num_tx_queues; i++) {
645 		memset(&tx, 0xff, sizeof(tx));
646 		if (ops->get_queue_stats_tx)
647 			ops->get_queue_stats_tx(netdev, i, &tx);
648 		netdev_nl_stats_add(&tx_sum, &tx, sizeof(tx));
649 	}
650 
651 	if (netdev_nl_stats_write_rx(rsp, &rx_sum) ||
652 	    netdev_nl_stats_write_tx(rsp, &tx_sum))
653 		goto nla_put_failure;
654 
655 	genlmsg_end(rsp, hdr);
656 	return 0;
657 
658 nla_put_failure:
659 	genlmsg_cancel(rsp, hdr);
660 	return -EMSGSIZE;
661 }
662 
663 static int
664 netdev_nl_qstats_get_dump_one(struct net_device *netdev, unsigned int scope,
665 			      struct sk_buff *skb, const struct genl_info *info,
666 			      struct netdev_nl_dump_ctx *ctx)
667 {
668 	if (!netdev->stat_ops)
669 		return 0;
670 
671 	switch (scope) {
672 	case 0:
673 		return netdev_nl_stats_by_netdev(netdev, skb, info);
674 	case NETDEV_QSTATS_SCOPE_QUEUE:
675 		return netdev_nl_stats_by_queue(netdev, skb, info, ctx);
676 	}
677 
678 	return -EINVAL;	/* Should not happen, per netlink policy */
679 }
680 
681 int netdev_nl_qstats_get_dumpit(struct sk_buff *skb,
682 				struct netlink_callback *cb)
683 {
684 	struct netdev_nl_dump_ctx *ctx = netdev_dump_ctx(cb);
685 	const struct genl_info *info = genl_info_dump(cb);
686 	struct net *net = sock_net(skb->sk);
687 	struct net_device *netdev;
688 	unsigned int ifindex;
689 	unsigned int scope;
690 	int err = 0;
691 
692 	scope = 0;
693 	if (info->attrs[NETDEV_A_QSTATS_SCOPE])
694 		scope = nla_get_uint(info->attrs[NETDEV_A_QSTATS_SCOPE]);
695 
696 	ifindex = 0;
697 	if (info->attrs[NETDEV_A_QSTATS_IFINDEX])
698 		ifindex = nla_get_u32(info->attrs[NETDEV_A_QSTATS_IFINDEX]);
699 
700 	rtnl_lock();
701 	if (ifindex) {
702 		netdev = __dev_get_by_index(net, ifindex);
703 		if (netdev && netdev->stat_ops) {
704 			err = netdev_nl_qstats_get_dump_one(netdev, scope, skb,
705 							    info, ctx);
706 		} else {
707 			NL_SET_BAD_ATTR(info->extack,
708 					info->attrs[NETDEV_A_QSTATS_IFINDEX]);
709 			err = netdev ? -EOPNOTSUPP : -ENODEV;
710 		}
711 	} else {
712 		for_each_netdev_dump(net, netdev, ctx->ifindex) {
713 			err = netdev_nl_qstats_get_dump_one(netdev, scope, skb,
714 							    info, ctx);
715 			if (err < 0)
716 				break;
717 		}
718 	}
719 	rtnl_unlock();
720 
721 	return err;
722 }
723 
724 static int netdev_genl_netdevice_event(struct notifier_block *nb,
725 				       unsigned long event, void *ptr)
726 {
727 	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
728 
729 	switch (event) {
730 	case NETDEV_REGISTER:
731 		netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_ADD_NTF);
732 		break;
733 	case NETDEV_UNREGISTER:
734 		netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_DEL_NTF);
735 		break;
736 	case NETDEV_XDP_FEAT_CHANGE:
737 		netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_CHANGE_NTF);
738 		break;
739 	}
740 
741 	return NOTIFY_OK;
742 }
743 
744 static struct notifier_block netdev_genl_nb = {
745 	.notifier_call	= netdev_genl_netdevice_event,
746 };
747 
748 static int __init netdev_genl_init(void)
749 {
750 	int err;
751 
752 	err = register_netdevice_notifier(&netdev_genl_nb);
753 	if (err)
754 		return err;
755 
756 	err = genl_register_family(&netdev_nl_family);
757 	if (err)
758 		goto err_unreg_ntf;
759 
760 	return 0;
761 
762 err_unreg_ntf:
763 	unregister_netdevice_notifier(&netdev_genl_nb);
764 	return err;
765 }
766 
767 subsys_initcall(netdev_genl_init);
768