xref: /linux/net/ethtool/netlink.c (revision 48dea9a700c8728cc31a1dd44588b97578de86ee)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <net/sock.h>
4 #include <linux/ethtool_netlink.h>
5 #include "netlink.h"
6 
7 static struct genl_family ethtool_genl_family;
8 
9 static bool ethnl_ok __read_mostly;
10 static u32 ethnl_bcast_seq;
11 
12 static const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_MAX + 1] = {
13 	[ETHTOOL_A_HEADER_UNSPEC]	= { .type = NLA_REJECT },
14 	[ETHTOOL_A_HEADER_DEV_INDEX]	= { .type = NLA_U32 },
15 	[ETHTOOL_A_HEADER_DEV_NAME]	= { .type = NLA_NUL_STRING,
16 					    .len = ALTIFNAMSIZ - 1 },
17 	[ETHTOOL_A_HEADER_FLAGS]	= { .type = NLA_U32 },
18 };
19 
20 /**
21  * ethnl_parse_header_dev_get() - parse request header
22  * @req_info:    structure to put results into
23  * @header:      nest attribute with request header
24  * @net:         request netns
25  * @extack:      netlink extack for error reporting
26  * @require_dev: fail if no device identified in header
27  *
28  * Parse request header in nested attribute @nest and puts results into
29  * the structure pointed to by @req_info. Extack from @info is used for error
30  * reporting. If req_info->dev is not null on return, reference to it has
31  * been taken. If error is returned, *req_info is null initialized and no
32  * reference is held.
33  *
34  * Return: 0 on success or negative error code
35  */
36 int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
37 			       const struct nlattr *header, struct net *net,
38 			       struct netlink_ext_ack *extack, bool require_dev)
39 {
40 	struct nlattr *tb[ETHTOOL_A_HEADER_MAX + 1];
41 	const struct nlattr *devname_attr;
42 	struct net_device *dev = NULL;
43 	u32 flags = 0;
44 	int ret;
45 
46 	if (!header) {
47 		NL_SET_ERR_MSG(extack, "request header missing");
48 		return -EINVAL;
49 	}
50 	ret = nla_parse_nested(tb, ETHTOOL_A_HEADER_MAX, header,
51 			       ethnl_header_policy, extack);
52 	if (ret < 0)
53 		return ret;
54 	if (tb[ETHTOOL_A_HEADER_FLAGS]) {
55 		flags = nla_get_u32(tb[ETHTOOL_A_HEADER_FLAGS]);
56 		if (flags & ~ETHTOOL_FLAG_ALL) {
57 			NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_HEADER_FLAGS],
58 					    "unrecognized request flags");
59 			nl_set_extack_cookie_u32(extack, ETHTOOL_FLAG_ALL);
60 			return -EOPNOTSUPP;
61 		}
62 	}
63 
64 	devname_attr = tb[ETHTOOL_A_HEADER_DEV_NAME];
65 	if (tb[ETHTOOL_A_HEADER_DEV_INDEX]) {
66 		u32 ifindex = nla_get_u32(tb[ETHTOOL_A_HEADER_DEV_INDEX]);
67 
68 		dev = dev_get_by_index(net, ifindex);
69 		if (!dev) {
70 			NL_SET_ERR_MSG_ATTR(extack,
71 					    tb[ETHTOOL_A_HEADER_DEV_INDEX],
72 					    "no device matches ifindex");
73 			return -ENODEV;
74 		}
75 		/* if both ifindex and ifname are passed, they must match */
76 		if (devname_attr &&
77 		    strncmp(dev->name, nla_data(devname_attr), IFNAMSIZ)) {
78 			dev_put(dev);
79 			NL_SET_ERR_MSG_ATTR(extack, header,
80 					    "ifindex and name do not match");
81 			return -ENODEV;
82 		}
83 	} else if (devname_attr) {
84 		dev = dev_get_by_name(net, nla_data(devname_attr));
85 		if (!dev) {
86 			NL_SET_ERR_MSG_ATTR(extack, devname_attr,
87 					    "no device matches name");
88 			return -ENODEV;
89 		}
90 	} else if (require_dev) {
91 		NL_SET_ERR_MSG_ATTR(extack, header,
92 				    "neither ifindex nor name specified");
93 		return -EINVAL;
94 	}
95 
96 	if (dev && !netif_device_present(dev)) {
97 		dev_put(dev);
98 		NL_SET_ERR_MSG(extack, "device not present");
99 		return -ENODEV;
100 	}
101 
102 	req_info->dev = dev;
103 	req_info->flags = flags;
104 	return 0;
105 }
106 
107 /**
108  * ethnl_fill_reply_header() - Put common header into a reply message
109  * @skb:      skb with the message
110  * @dev:      network device to describe in header
111  * @attrtype: attribute type to use for the nest
112  *
113  * Create a nested attribute with attributes describing given network device.
114  *
115  * Return: 0 on success, error value (-EMSGSIZE only) on error
116  */
117 int ethnl_fill_reply_header(struct sk_buff *skb, struct net_device *dev,
118 			    u16 attrtype)
119 {
120 	struct nlattr *nest;
121 
122 	if (!dev)
123 		return 0;
124 	nest = nla_nest_start(skb, attrtype);
125 	if (!nest)
126 		return -EMSGSIZE;
127 
128 	if (nla_put_u32(skb, ETHTOOL_A_HEADER_DEV_INDEX, (u32)dev->ifindex) ||
129 	    nla_put_string(skb, ETHTOOL_A_HEADER_DEV_NAME, dev->name))
130 		goto nla_put_failure;
131 	/* If more attributes are put into reply header, ethnl_header_size()
132 	 * must be updated to account for them.
133 	 */
134 
135 	nla_nest_end(skb, nest);
136 	return 0;
137 
138 nla_put_failure:
139 	nla_nest_cancel(skb, nest);
140 	return -EMSGSIZE;
141 }
142 
143 /**
144  * ethnl_reply_init() - Create skb for a reply and fill device identification
145  * @payload:      payload length (without netlink and genetlink header)
146  * @dev:          device the reply is about (may be null)
147  * @cmd:          ETHTOOL_MSG_* message type for reply
148  * @hdr_attrtype: attribute type for common header
149  * @info:         genetlink info of the received packet we respond to
150  * @ehdrp:        place to store payload pointer returned by genlmsg_new()
151  *
152  * Return: pointer to allocated skb on success, NULL on error
153  */
154 struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd,
155 				 u16 hdr_attrtype, struct genl_info *info,
156 				 void **ehdrp)
157 {
158 	struct sk_buff *skb;
159 
160 	skb = genlmsg_new(payload, GFP_KERNEL);
161 	if (!skb)
162 		goto err;
163 	*ehdrp = genlmsg_put_reply(skb, info, &ethtool_genl_family, 0, cmd);
164 	if (!*ehdrp)
165 		goto err_free;
166 
167 	if (dev) {
168 		int ret;
169 
170 		ret = ethnl_fill_reply_header(skb, dev, hdr_attrtype);
171 		if (ret < 0)
172 			goto err_free;
173 	}
174 	return skb;
175 
176 err_free:
177 	nlmsg_free(skb);
178 err:
179 	if (info)
180 		GENL_SET_ERR_MSG(info, "failed to setup reply message");
181 	return NULL;
182 }
183 
184 void *ethnl_dump_put(struct sk_buff *skb, struct netlink_callback *cb, u8 cmd)
185 {
186 	return genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
187 			   &ethtool_genl_family, 0, cmd);
188 }
189 
190 void *ethnl_bcastmsg_put(struct sk_buff *skb, u8 cmd)
191 {
192 	return genlmsg_put(skb, 0, ++ethnl_bcast_seq, &ethtool_genl_family, 0,
193 			   cmd);
194 }
195 
196 int ethnl_multicast(struct sk_buff *skb, struct net_device *dev)
197 {
198 	return genlmsg_multicast_netns(&ethtool_genl_family, dev_net(dev), skb,
199 				       0, ETHNL_MCGRP_MONITOR, GFP_KERNEL);
200 }
201 
202 /* GET request helpers */
203 
204 /**
205  * struct ethnl_dump_ctx - context structure for generic dumpit() callback
206  * @ops:        request ops of currently processed message type
207  * @req_info:   parsed request header of processed request
208  * @reply_data: data needed to compose the reply
209  * @pos_hash:   saved iteration position - hashbucket
210  * @pos_idx:    saved iteration position - index
211  *
212  * These parameters are kept in struct netlink_callback as context preserved
213  * between iterations. They are initialized by ethnl_default_start() and used
214  * in ethnl_default_dumpit() and ethnl_default_done().
215  */
216 struct ethnl_dump_ctx {
217 	const struct ethnl_request_ops	*ops;
218 	struct ethnl_req_info		*req_info;
219 	struct ethnl_reply_data		*reply_data;
220 	int				pos_hash;
221 	int				pos_idx;
222 };
223 
224 static const struct ethnl_request_ops *
225 ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
226 	[ETHTOOL_MSG_STRSET_GET]	= &ethnl_strset_request_ops,
227 	[ETHTOOL_MSG_LINKINFO_GET]	= &ethnl_linkinfo_request_ops,
228 	[ETHTOOL_MSG_LINKMODES_GET]	= &ethnl_linkmodes_request_ops,
229 	[ETHTOOL_MSG_LINKSTATE_GET]	= &ethnl_linkstate_request_ops,
230 	[ETHTOOL_MSG_DEBUG_GET]		= &ethnl_debug_request_ops,
231 	[ETHTOOL_MSG_WOL_GET]		= &ethnl_wol_request_ops,
232 	[ETHTOOL_MSG_FEATURES_GET]	= &ethnl_features_request_ops,
233 	[ETHTOOL_MSG_PRIVFLAGS_GET]	= &ethnl_privflags_request_ops,
234 	[ETHTOOL_MSG_RINGS_GET]		= &ethnl_rings_request_ops,
235 	[ETHTOOL_MSG_CHANNELS_GET]	= &ethnl_channels_request_ops,
236 	[ETHTOOL_MSG_COALESCE_GET]	= &ethnl_coalesce_request_ops,
237 	[ETHTOOL_MSG_PAUSE_GET]		= &ethnl_pause_request_ops,
238 	[ETHTOOL_MSG_EEE_GET]		= &ethnl_eee_request_ops,
239 	[ETHTOOL_MSG_TSINFO_GET]	= &ethnl_tsinfo_request_ops,
240 };
241 
242 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
243 {
244 	return (struct ethnl_dump_ctx *)cb->ctx;
245 }
246 
247 /**
248  * ethnl_default_parse() - Parse request message
249  * @req_info:    pointer to structure to put data into
250  * @nlhdr:       pointer to request message header
251  * @net:         request netns
252  * @request_ops: struct request_ops for request type
253  * @extack:      netlink extack for error reporting
254  * @require_dev: fail if no device identified in header
255  *
256  * Parse universal request header and call request specific ->parse_request()
257  * callback (if defined) to parse the rest of the message.
258  *
259  * Return: 0 on success or negative error code
260  */
261 static int ethnl_default_parse(struct ethnl_req_info *req_info,
262 			       const struct nlmsghdr *nlhdr, struct net *net,
263 			       const struct ethnl_request_ops *request_ops,
264 			       struct netlink_ext_ack *extack, bool require_dev)
265 {
266 	struct nlattr **tb;
267 	int ret;
268 
269 	tb = kmalloc_array(request_ops->max_attr + 1, sizeof(tb[0]),
270 			   GFP_KERNEL);
271 	if (!tb)
272 		return -ENOMEM;
273 
274 	ret = nlmsg_parse(nlhdr, GENL_HDRLEN, tb, request_ops->max_attr,
275 			  request_ops->request_policy, extack);
276 	if (ret < 0)
277 		goto out;
278 	ret = ethnl_parse_header_dev_get(req_info, tb[request_ops->hdr_attr],
279 					 net, extack, require_dev);
280 	if (ret < 0)
281 		goto out;
282 
283 	if (request_ops->parse_request) {
284 		ret = request_ops->parse_request(req_info, tb, extack);
285 		if (ret < 0)
286 			goto out;
287 	}
288 
289 	ret = 0;
290 out:
291 	kfree(tb);
292 	return ret;
293 }
294 
295 /**
296  * ethnl_init_reply_data() - Initialize reply data for GET request
297  * @reply_data: pointer to embedded struct ethnl_reply_data
298  * @ops:        instance of struct ethnl_request_ops describing the layout
299  * @dev:        network device to initialize the reply for
300  *
301  * Fills the reply data part with zeros and sets the dev member. Must be called
302  * before calling the ->fill_reply() callback (for each iteration when handling
303  * dump requests).
304  */
305 static void ethnl_init_reply_data(struct ethnl_reply_data *reply_data,
306 				  const struct ethnl_request_ops *ops,
307 				  struct net_device *dev)
308 {
309 	memset(reply_data, 0, ops->reply_data_size);
310 	reply_data->dev = dev;
311 }
312 
313 /* default ->doit() handler for GET type requests */
314 static int ethnl_default_doit(struct sk_buff *skb, struct genl_info *info)
315 {
316 	struct ethnl_reply_data *reply_data = NULL;
317 	struct ethnl_req_info *req_info = NULL;
318 	const u8 cmd = info->genlhdr->cmd;
319 	const struct ethnl_request_ops *ops;
320 	struct sk_buff *rskb;
321 	void *reply_payload;
322 	int reply_len;
323 	int ret;
324 
325 	ops = ethnl_default_requests[cmd];
326 	if (WARN_ONCE(!ops, "cmd %u has no ethnl_request_ops\n", cmd))
327 		return -EOPNOTSUPP;
328 	req_info = kzalloc(ops->req_info_size, GFP_KERNEL);
329 	if (!req_info)
330 		return -ENOMEM;
331 	reply_data = kmalloc(ops->reply_data_size, GFP_KERNEL);
332 	if (!reply_data) {
333 		kfree(req_info);
334 		return -ENOMEM;
335 	}
336 
337 	ret = ethnl_default_parse(req_info, info->nlhdr, genl_info_net(info), ops,
338 				  info->extack, !ops->allow_nodev_do);
339 	if (ret < 0)
340 		goto err_dev;
341 	ethnl_init_reply_data(reply_data, ops, req_info->dev);
342 
343 	rtnl_lock();
344 	ret = ops->prepare_data(req_info, reply_data, info);
345 	rtnl_unlock();
346 	if (ret < 0)
347 		goto err_cleanup;
348 	ret = ops->reply_size(req_info, reply_data);
349 	if (ret < 0)
350 		goto err_cleanup;
351 	reply_len = ret + ethnl_reply_header_size();
352 	ret = -ENOMEM;
353 	rskb = ethnl_reply_init(reply_len, req_info->dev, ops->reply_cmd,
354 				ops->hdr_attr, info, &reply_payload);
355 	if (!rskb)
356 		goto err_cleanup;
357 	ret = ops->fill_reply(rskb, req_info, reply_data);
358 	if (ret < 0)
359 		goto err_msg;
360 	if (ops->cleanup_data)
361 		ops->cleanup_data(reply_data);
362 
363 	genlmsg_end(rskb, reply_payload);
364 	if (req_info->dev)
365 		dev_put(req_info->dev);
366 	kfree(reply_data);
367 	kfree(req_info);
368 	return genlmsg_reply(rskb, info);
369 
370 err_msg:
371 	WARN_ONCE(ret == -EMSGSIZE, "calculated message payload length (%d) not sufficient\n", reply_len);
372 	nlmsg_free(rskb);
373 err_cleanup:
374 	if (ops->cleanup_data)
375 		ops->cleanup_data(reply_data);
376 err_dev:
377 	if (req_info->dev)
378 		dev_put(req_info->dev);
379 	kfree(reply_data);
380 	kfree(req_info);
381 	return ret;
382 }
383 
384 static int ethnl_default_dump_one(struct sk_buff *skb, struct net_device *dev,
385 				  const struct ethnl_dump_ctx *ctx,
386 				  struct netlink_callback *cb)
387 {
388 	void *ehdr;
389 	int ret;
390 
391 	ehdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
392 			   &ethtool_genl_family, 0, ctx->ops->reply_cmd);
393 	if (!ehdr)
394 		return -EMSGSIZE;
395 
396 	ethnl_init_reply_data(ctx->reply_data, ctx->ops, dev);
397 	rtnl_lock();
398 	ret = ctx->ops->prepare_data(ctx->req_info, ctx->reply_data, NULL);
399 	rtnl_unlock();
400 	if (ret < 0)
401 		goto out;
402 	ret = ethnl_fill_reply_header(skb, dev, ctx->ops->hdr_attr);
403 	if (ret < 0)
404 		goto out;
405 	ret = ctx->ops->fill_reply(skb, ctx->req_info, ctx->reply_data);
406 
407 out:
408 	if (ctx->ops->cleanup_data)
409 		ctx->ops->cleanup_data(ctx->reply_data);
410 	ctx->reply_data->dev = NULL;
411 	if (ret < 0)
412 		genlmsg_cancel(skb, ehdr);
413 	else
414 		genlmsg_end(skb, ehdr);
415 	return ret;
416 }
417 
418 /* Default ->dumpit() handler for GET requests. Device iteration copied from
419  * rtnl_dump_ifinfo(); we have to be more careful about device hashtable
420  * persistence as we cannot guarantee to hold RTNL lock through the whole
421  * function as rtnetnlink does.
422  */
423 static int ethnl_default_dumpit(struct sk_buff *skb,
424 				struct netlink_callback *cb)
425 {
426 	struct ethnl_dump_ctx *ctx = ethnl_dump_context(cb);
427 	struct net *net = sock_net(skb->sk);
428 	int s_idx = ctx->pos_idx;
429 	int h, idx = 0;
430 	int ret = 0;
431 
432 	rtnl_lock();
433 	for (h = ctx->pos_hash; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
434 		struct hlist_head *head;
435 		struct net_device *dev;
436 		unsigned int seq;
437 
438 		head = &net->dev_index_head[h];
439 
440 restart_chain:
441 		seq = net->dev_base_seq;
442 		cb->seq = seq;
443 		idx = 0;
444 		hlist_for_each_entry(dev, head, index_hlist) {
445 			if (idx < s_idx)
446 				goto cont;
447 			dev_hold(dev);
448 			rtnl_unlock();
449 
450 			ret = ethnl_default_dump_one(skb, dev, ctx, cb);
451 			dev_put(dev);
452 			if (ret < 0) {
453 				if (ret == -EOPNOTSUPP)
454 					goto lock_and_cont;
455 				if (likely(skb->len))
456 					ret = skb->len;
457 				goto out;
458 			}
459 lock_and_cont:
460 			rtnl_lock();
461 			if (net->dev_base_seq != seq) {
462 				s_idx = idx + 1;
463 				goto restart_chain;
464 			}
465 cont:
466 			idx++;
467 		}
468 
469 	}
470 	rtnl_unlock();
471 
472 out:
473 	ctx->pos_hash = h;
474 	ctx->pos_idx = idx;
475 	nl_dump_check_consistent(cb, nlmsg_hdr(skb));
476 
477 	return ret;
478 }
479 
480 /* generic ->start() handler for GET requests */
481 static int ethnl_default_start(struct netlink_callback *cb)
482 {
483 	struct ethnl_dump_ctx *ctx = ethnl_dump_context(cb);
484 	struct ethnl_reply_data *reply_data;
485 	const struct ethnl_request_ops *ops;
486 	struct ethnl_req_info *req_info;
487 	struct genlmsghdr *ghdr;
488 	int ret;
489 
490 	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
491 
492 	ghdr = nlmsg_data(cb->nlh);
493 	ops = ethnl_default_requests[ghdr->cmd];
494 	if (WARN_ONCE(!ops, "cmd %u has no ethnl_request_ops\n", ghdr->cmd))
495 		return -EOPNOTSUPP;
496 	req_info = kzalloc(ops->req_info_size, GFP_KERNEL);
497 	if (!req_info)
498 		return -ENOMEM;
499 	reply_data = kmalloc(ops->reply_data_size, GFP_KERNEL);
500 	if (!reply_data) {
501 		ret = -ENOMEM;
502 		goto free_req_info;
503 	}
504 
505 	ret = ethnl_default_parse(req_info, cb->nlh, sock_net(cb->skb->sk), ops,
506 				  cb->extack, false);
507 	if (req_info->dev) {
508 		/* We ignore device specification in dump requests but as the
509 		 * same parser as for non-dump (doit) requests is used, it
510 		 * would take reference to the device if it finds one
511 		 */
512 		dev_put(req_info->dev);
513 		req_info->dev = NULL;
514 	}
515 	if (ret < 0)
516 		goto free_reply_data;
517 
518 	ctx->ops = ops;
519 	ctx->req_info = req_info;
520 	ctx->reply_data = reply_data;
521 	ctx->pos_hash = 0;
522 	ctx->pos_idx = 0;
523 
524 	return 0;
525 
526 free_reply_data:
527 	kfree(reply_data);
528 free_req_info:
529 	kfree(req_info);
530 
531 	return ret;
532 }
533 
534 /* default ->done() handler for GET requests */
535 static int ethnl_default_done(struct netlink_callback *cb)
536 {
537 	struct ethnl_dump_ctx *ctx = ethnl_dump_context(cb);
538 
539 	kfree(ctx->reply_data);
540 	kfree(ctx->req_info);
541 
542 	return 0;
543 }
544 
545 static const struct ethnl_request_ops *
546 ethnl_default_notify_ops[ETHTOOL_MSG_KERNEL_MAX + 1] = {
547 	[ETHTOOL_MSG_LINKINFO_NTF]	= &ethnl_linkinfo_request_ops,
548 	[ETHTOOL_MSG_LINKMODES_NTF]	= &ethnl_linkmodes_request_ops,
549 	[ETHTOOL_MSG_DEBUG_NTF]		= &ethnl_debug_request_ops,
550 	[ETHTOOL_MSG_WOL_NTF]		= &ethnl_wol_request_ops,
551 	[ETHTOOL_MSG_FEATURES_NTF]	= &ethnl_features_request_ops,
552 	[ETHTOOL_MSG_PRIVFLAGS_NTF]	= &ethnl_privflags_request_ops,
553 	[ETHTOOL_MSG_RINGS_NTF]		= &ethnl_rings_request_ops,
554 	[ETHTOOL_MSG_CHANNELS_NTF]	= &ethnl_channels_request_ops,
555 	[ETHTOOL_MSG_COALESCE_NTF]	= &ethnl_coalesce_request_ops,
556 	[ETHTOOL_MSG_PAUSE_NTF]		= &ethnl_pause_request_ops,
557 	[ETHTOOL_MSG_EEE_NTF]		= &ethnl_eee_request_ops,
558 };
559 
560 /* default notification handler */
561 static void ethnl_default_notify(struct net_device *dev, unsigned int cmd,
562 				 const void *data)
563 {
564 	struct ethnl_reply_data *reply_data;
565 	const struct ethnl_request_ops *ops;
566 	struct ethnl_req_info *req_info;
567 	struct sk_buff *skb;
568 	void *reply_payload;
569 	int reply_len;
570 	int ret;
571 
572 	if (WARN_ONCE(cmd > ETHTOOL_MSG_KERNEL_MAX ||
573 		      !ethnl_default_notify_ops[cmd],
574 		      "unexpected notification type %u\n", cmd))
575 		return;
576 	ops = ethnl_default_notify_ops[cmd];
577 	req_info = kzalloc(ops->req_info_size, GFP_KERNEL);
578 	if (!req_info)
579 		return;
580 	reply_data = kmalloc(ops->reply_data_size, GFP_KERNEL);
581 	if (!reply_data) {
582 		kfree(req_info);
583 		return;
584 	}
585 
586 	req_info->dev = dev;
587 	req_info->flags |= ETHTOOL_FLAG_COMPACT_BITSETS;
588 
589 	ethnl_init_reply_data(reply_data, ops, dev);
590 	ret = ops->prepare_data(req_info, reply_data, NULL);
591 	if (ret < 0)
592 		goto err_cleanup;
593 	ret = ops->reply_size(req_info, reply_data);
594 	if (ret < 0)
595 		goto err_cleanup;
596 	reply_len = ret + ethnl_reply_header_size();
597 	ret = -ENOMEM;
598 	skb = genlmsg_new(reply_len, GFP_KERNEL);
599 	if (!skb)
600 		goto err_cleanup;
601 	reply_payload = ethnl_bcastmsg_put(skb, cmd);
602 	if (!reply_payload)
603 		goto err_skb;
604 	ret = ethnl_fill_reply_header(skb, dev, ops->hdr_attr);
605 	if (ret < 0)
606 		goto err_msg;
607 	ret = ops->fill_reply(skb, req_info, reply_data);
608 	if (ret < 0)
609 		goto err_msg;
610 	if (ops->cleanup_data)
611 		ops->cleanup_data(reply_data);
612 
613 	genlmsg_end(skb, reply_payload);
614 	kfree(reply_data);
615 	kfree(req_info);
616 	ethnl_multicast(skb, dev);
617 	return;
618 
619 err_msg:
620 	WARN_ONCE(ret == -EMSGSIZE,
621 		  "calculated message payload length (%d) not sufficient\n",
622 		  reply_len);
623 err_skb:
624 	nlmsg_free(skb);
625 err_cleanup:
626 	if (ops->cleanup_data)
627 		ops->cleanup_data(reply_data);
628 	kfree(reply_data);
629 	kfree(req_info);
630 	return;
631 }
632 
633 /* notifications */
634 
635 typedef void (*ethnl_notify_handler_t)(struct net_device *dev, unsigned int cmd,
636 				       const void *data);
637 
638 static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
639 	[ETHTOOL_MSG_LINKINFO_NTF]	= ethnl_default_notify,
640 	[ETHTOOL_MSG_LINKMODES_NTF]	= ethnl_default_notify,
641 	[ETHTOOL_MSG_DEBUG_NTF]		= ethnl_default_notify,
642 	[ETHTOOL_MSG_WOL_NTF]		= ethnl_default_notify,
643 	[ETHTOOL_MSG_FEATURES_NTF]	= ethnl_default_notify,
644 	[ETHTOOL_MSG_PRIVFLAGS_NTF]	= ethnl_default_notify,
645 	[ETHTOOL_MSG_RINGS_NTF]		= ethnl_default_notify,
646 	[ETHTOOL_MSG_CHANNELS_NTF]	= ethnl_default_notify,
647 	[ETHTOOL_MSG_COALESCE_NTF]	= ethnl_default_notify,
648 	[ETHTOOL_MSG_PAUSE_NTF]		= ethnl_default_notify,
649 	[ETHTOOL_MSG_EEE_NTF]		= ethnl_default_notify,
650 };
651 
652 void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)
653 {
654 	if (unlikely(!ethnl_ok))
655 		return;
656 	ASSERT_RTNL();
657 
658 	if (likely(cmd < ARRAY_SIZE(ethnl_notify_handlers) &&
659 		   ethnl_notify_handlers[cmd]))
660 		ethnl_notify_handlers[cmd](dev, cmd, data);
661 	else
662 		WARN_ONCE(1, "notification %u not implemented (dev=%s)\n",
663 			  cmd, netdev_name(dev));
664 }
665 EXPORT_SYMBOL(ethtool_notify);
666 
667 static void ethnl_notify_features(struct netdev_notifier_info *info)
668 {
669 	struct net_device *dev = netdev_notifier_info_to_dev(info);
670 
671 	ethtool_notify(dev, ETHTOOL_MSG_FEATURES_NTF, NULL);
672 }
673 
674 static int ethnl_netdev_event(struct notifier_block *this, unsigned long event,
675 			      void *ptr)
676 {
677 	switch (event) {
678 	case NETDEV_FEAT_CHANGE:
679 		ethnl_notify_features(ptr);
680 		break;
681 	}
682 
683 	return NOTIFY_DONE;
684 }
685 
686 static struct notifier_block ethnl_netdev_notifier = {
687 	.notifier_call = ethnl_netdev_event,
688 };
689 
690 /* genetlink setup */
691 
692 static const struct genl_ops ethtool_genl_ops[] = {
693 	{
694 		.cmd	= ETHTOOL_MSG_STRSET_GET,
695 		.doit	= ethnl_default_doit,
696 		.start	= ethnl_default_start,
697 		.dumpit	= ethnl_default_dumpit,
698 		.done	= ethnl_default_done,
699 	},
700 	{
701 		.cmd	= ETHTOOL_MSG_LINKINFO_GET,
702 		.doit	= ethnl_default_doit,
703 		.start	= ethnl_default_start,
704 		.dumpit	= ethnl_default_dumpit,
705 		.done	= ethnl_default_done,
706 	},
707 	{
708 		.cmd	= ETHTOOL_MSG_LINKINFO_SET,
709 		.flags	= GENL_UNS_ADMIN_PERM,
710 		.doit	= ethnl_set_linkinfo,
711 	},
712 	{
713 		.cmd	= ETHTOOL_MSG_LINKMODES_GET,
714 		.doit	= ethnl_default_doit,
715 		.start	= ethnl_default_start,
716 		.dumpit	= ethnl_default_dumpit,
717 		.done	= ethnl_default_done,
718 	},
719 	{
720 		.cmd	= ETHTOOL_MSG_LINKMODES_SET,
721 		.flags	= GENL_UNS_ADMIN_PERM,
722 		.doit	= ethnl_set_linkmodes,
723 	},
724 	{
725 		.cmd	= ETHTOOL_MSG_LINKSTATE_GET,
726 		.doit	= ethnl_default_doit,
727 		.start	= ethnl_default_start,
728 		.dumpit	= ethnl_default_dumpit,
729 		.done	= ethnl_default_done,
730 	},
731 	{
732 		.cmd	= ETHTOOL_MSG_DEBUG_GET,
733 		.doit	= ethnl_default_doit,
734 		.start	= ethnl_default_start,
735 		.dumpit	= ethnl_default_dumpit,
736 		.done	= ethnl_default_done,
737 	},
738 	{
739 		.cmd	= ETHTOOL_MSG_DEBUG_SET,
740 		.flags	= GENL_UNS_ADMIN_PERM,
741 		.doit	= ethnl_set_debug,
742 	},
743 	{
744 		.cmd	= ETHTOOL_MSG_WOL_GET,
745 		.flags	= GENL_UNS_ADMIN_PERM,
746 		.doit	= ethnl_default_doit,
747 		.start	= ethnl_default_start,
748 		.dumpit	= ethnl_default_dumpit,
749 		.done	= ethnl_default_done,
750 	},
751 	{
752 		.cmd	= ETHTOOL_MSG_WOL_SET,
753 		.flags	= GENL_UNS_ADMIN_PERM,
754 		.doit	= ethnl_set_wol,
755 	},
756 	{
757 		.cmd	= ETHTOOL_MSG_FEATURES_GET,
758 		.doit	= ethnl_default_doit,
759 		.start	= ethnl_default_start,
760 		.dumpit	= ethnl_default_dumpit,
761 		.done	= ethnl_default_done,
762 	},
763 	{
764 		.cmd	= ETHTOOL_MSG_FEATURES_SET,
765 		.flags	= GENL_UNS_ADMIN_PERM,
766 		.doit	= ethnl_set_features,
767 	},
768 	{
769 		.cmd	= ETHTOOL_MSG_PRIVFLAGS_GET,
770 		.doit	= ethnl_default_doit,
771 		.start	= ethnl_default_start,
772 		.dumpit	= ethnl_default_dumpit,
773 		.done	= ethnl_default_done,
774 	},
775 	{
776 		.cmd	= ETHTOOL_MSG_PRIVFLAGS_SET,
777 		.flags	= GENL_UNS_ADMIN_PERM,
778 		.doit	= ethnl_set_privflags,
779 	},
780 	{
781 		.cmd	= ETHTOOL_MSG_RINGS_GET,
782 		.doit	= ethnl_default_doit,
783 		.start	= ethnl_default_start,
784 		.dumpit	= ethnl_default_dumpit,
785 		.done	= ethnl_default_done,
786 	},
787 	{
788 		.cmd	= ETHTOOL_MSG_RINGS_SET,
789 		.flags	= GENL_UNS_ADMIN_PERM,
790 		.doit	= ethnl_set_rings,
791 	},
792 	{
793 		.cmd	= ETHTOOL_MSG_CHANNELS_GET,
794 		.doit	= ethnl_default_doit,
795 		.start	= ethnl_default_start,
796 		.dumpit	= ethnl_default_dumpit,
797 		.done	= ethnl_default_done,
798 	},
799 	{
800 		.cmd	= ETHTOOL_MSG_CHANNELS_SET,
801 		.flags	= GENL_UNS_ADMIN_PERM,
802 		.doit	= ethnl_set_channels,
803 	},
804 	{
805 		.cmd	= ETHTOOL_MSG_COALESCE_GET,
806 		.doit	= ethnl_default_doit,
807 		.start	= ethnl_default_start,
808 		.dumpit	= ethnl_default_dumpit,
809 		.done	= ethnl_default_done,
810 	},
811 	{
812 		.cmd	= ETHTOOL_MSG_COALESCE_SET,
813 		.flags	= GENL_UNS_ADMIN_PERM,
814 		.doit	= ethnl_set_coalesce,
815 	},
816 	{
817 		.cmd	= ETHTOOL_MSG_PAUSE_GET,
818 		.doit	= ethnl_default_doit,
819 		.start	= ethnl_default_start,
820 		.dumpit	= ethnl_default_dumpit,
821 		.done	= ethnl_default_done,
822 	},
823 	{
824 		.cmd	= ETHTOOL_MSG_PAUSE_SET,
825 		.flags	= GENL_UNS_ADMIN_PERM,
826 		.doit	= ethnl_set_pause,
827 	},
828 	{
829 		.cmd	= ETHTOOL_MSG_EEE_GET,
830 		.doit	= ethnl_default_doit,
831 		.start	= ethnl_default_start,
832 		.dumpit	= ethnl_default_dumpit,
833 		.done	= ethnl_default_done,
834 	},
835 	{
836 		.cmd	= ETHTOOL_MSG_EEE_SET,
837 		.flags	= GENL_UNS_ADMIN_PERM,
838 		.doit	= ethnl_set_eee,
839 	},
840 	{
841 		.cmd	= ETHTOOL_MSG_TSINFO_GET,
842 		.doit	= ethnl_default_doit,
843 		.start	= ethnl_default_start,
844 		.dumpit	= ethnl_default_dumpit,
845 		.done	= ethnl_default_done,
846 	},
847 	{
848 		.cmd	= ETHTOOL_MSG_CABLE_TEST_ACT,
849 		.flags	= GENL_UNS_ADMIN_PERM,
850 		.doit	= ethnl_act_cable_test,
851 	},
852 	{
853 		.cmd	= ETHTOOL_MSG_CABLE_TEST_TDR_ACT,
854 		.flags	= GENL_UNS_ADMIN_PERM,
855 		.doit	= ethnl_act_cable_test_tdr,
856 	},
857 	{
858 		.cmd	= ETHTOOL_MSG_TUNNEL_INFO_GET,
859 		.doit	= ethnl_tunnel_info_doit,
860 		.start	= ethnl_tunnel_info_start,
861 		.dumpit	= ethnl_tunnel_info_dumpit,
862 	},
863 };
864 
865 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
866 	[ETHNL_MCGRP_MONITOR] = { .name = ETHTOOL_MCGRP_MONITOR_NAME },
867 };
868 
869 static struct genl_family ethtool_genl_family = {
870 	.name		= ETHTOOL_GENL_NAME,
871 	.version	= ETHTOOL_GENL_VERSION,
872 	.netnsok	= true,
873 	.parallel_ops	= true,
874 	.ops		= ethtool_genl_ops,
875 	.n_ops		= ARRAY_SIZE(ethtool_genl_ops),
876 	.mcgrps		= ethtool_nl_mcgrps,
877 	.n_mcgrps	= ARRAY_SIZE(ethtool_nl_mcgrps),
878 };
879 
880 /* module setup */
881 
882 static int __init ethnl_init(void)
883 {
884 	int ret;
885 
886 	ret = genl_register_family(&ethtool_genl_family);
887 	if (WARN(ret < 0, "ethtool: genetlink family registration failed"))
888 		return ret;
889 	ethnl_ok = true;
890 
891 	ret = register_netdevice_notifier(&ethnl_netdev_notifier);
892 	WARN(ret < 0, "ethtool: net device notifier registration failed");
893 	return ret;
894 }
895 
896 subsys_initcall(ethnl_init);
897