xref: /linux/net/ethtool/netlink.h (revision 24ce659dcc02c21f8d6c0a7589c3320a4dfa8152)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 
3 #ifndef _NET_ETHTOOL_NETLINK_H
4 #define _NET_ETHTOOL_NETLINK_H
5 
6 #include <linux/ethtool_netlink.h>
7 #include <linux/netdevice.h>
8 #include <net/genetlink.h>
9 #include <net/sock.h>
10 
11 struct ethnl_req_info;
12 
13 int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
14 			       const struct nlattr *nest, struct net *net,
15 			       struct netlink_ext_ack *extack,
16 			       bool require_dev);
17 int ethnl_fill_reply_header(struct sk_buff *skb, struct net_device *dev,
18 			    u16 attrtype);
19 struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd,
20 				 u16 hdr_attrtype, struct genl_info *info,
21 				 void **ehdrp);
22 
23 /**
24  * ethnl_strz_size() - calculate attribute length for fixed size string
25  * @s: ETH_GSTRING_LEN sized string (may not be null terminated)
26  *
27  * Return: total length of an attribute with null terminated string from @s
28  */
29 static inline int ethnl_strz_size(const char *s)
30 {
31 	return nla_total_size(strnlen(s, ETH_GSTRING_LEN) + 1);
32 }
33 
34 /**
35  * ethnl_put_strz() - put string attribute with fixed size string
36  * @skb:     skb with the message
37  * @attrype: attribute type
38  * @s:       ETH_GSTRING_LEN sized string (may not be null terminated)
39  *
40  * Puts an attribute with null terminated string from @s into the message.
41  *
42  * Return: 0 on success, negative error code on failure
43  */
44 static inline int ethnl_put_strz(struct sk_buff *skb, u16 attrtype,
45 				 const char *s)
46 {
47 	unsigned int len = strnlen(s, ETH_GSTRING_LEN);
48 	struct nlattr *attr;
49 
50 	attr = nla_reserve(skb, attrtype, len + 1);
51 	if (!attr)
52 		return -EMSGSIZE;
53 
54 	memcpy(nla_data(attr), s, len);
55 	((char *)nla_data(attr))[len] = '\0';
56 	return 0;
57 }
58 
59 /**
60  * ethnl_update_u32() - update u32 value from NLA_U32 attribute
61  * @dst:  value to update
62  * @attr: netlink attribute with new value or null
63  * @mod:  pointer to bool for modification tracking
64  *
65  * Copy the u32 value from NLA_U32 netlink attribute @attr into variable
66  * pointed to by @dst; do nothing if @attr is null. Bool pointed to by @mod
67  * is set to true if this function changed the value of *dst, otherwise it
68  * is left as is.
69  */
70 static inline void ethnl_update_u32(u32 *dst, const struct nlattr *attr,
71 				    bool *mod)
72 {
73 	u32 val;
74 
75 	if (!attr)
76 		return;
77 	val = nla_get_u32(attr);
78 	if (*dst == val)
79 		return;
80 
81 	*dst = val;
82 	*mod = true;
83 }
84 
85 /**
86  * ethnl_update_u8() - update u8 value from NLA_U8 attribute
87  * @dst:  value to update
88  * @attr: netlink attribute with new value or null
89  * @mod:  pointer to bool for modification tracking
90  *
91  * Copy the u8 value from NLA_U8 netlink attribute @attr into variable
92  * pointed to by @dst; do nothing if @attr is null. Bool pointed to by @mod
93  * is set to true if this function changed the value of *dst, otherwise it
94  * is left as is.
95  */
96 static inline void ethnl_update_u8(u8 *dst, const struct nlattr *attr,
97 				   bool *mod)
98 {
99 	u8 val;
100 
101 	if (!attr)
102 		return;
103 	val = nla_get_u8(attr);
104 	if (*dst == val)
105 		return;
106 
107 	*dst = val;
108 	*mod = true;
109 }
110 
111 /**
112  * ethnl_update_bool32() - update u32 used as bool from NLA_U8 attribute
113  * @dst:  value to update
114  * @attr: netlink attribute with new value or null
115  * @mod:  pointer to bool for modification tracking
116  *
117  * Use the u8 value from NLA_U8 netlink attribute @attr to set u32 variable
118  * pointed to by @dst to 0 (if zero) or 1 (if not); do nothing if @attr is
119  * null. Bool pointed to by @mod is set to true if this function changed the
120  * logical value of *dst, otherwise it is left as is.
121  */
122 static inline void ethnl_update_bool32(u32 *dst, const struct nlattr *attr,
123 				       bool *mod)
124 {
125 	u8 val;
126 
127 	if (!attr)
128 		return;
129 	val = !!nla_get_u8(attr);
130 	if (!!*dst == val)
131 		return;
132 
133 	*dst = val;
134 	*mod = true;
135 }
136 
137 /**
138  * ethnl_update_binary() - update binary data from NLA_BINARY atribute
139  * @dst:  value to update
140  * @len:  destination buffer length
141  * @attr: netlink attribute with new value or null
142  * @mod:  pointer to bool for modification tracking
143  *
144  * Use the u8 value from NLA_U8 netlink attribute @attr to rewrite data block
145  * of length @len at @dst by attribute payload; do nothing if @attr is null.
146  * Bool pointed to by @mod is set to true if this function changed the logical
147  * value of *dst, otherwise it is left as is.
148  */
149 static inline void ethnl_update_binary(void *dst, unsigned int len,
150 				       const struct nlattr *attr, bool *mod)
151 {
152 	if (!attr)
153 		return;
154 	if (nla_len(attr) < len)
155 		len = nla_len(attr);
156 	if (!memcmp(dst, nla_data(attr), len))
157 		return;
158 
159 	memcpy(dst, nla_data(attr), len);
160 	*mod = true;
161 }
162 
163 /**
164  * ethnl_update_bitfield32() - update u32 value from NLA_BITFIELD32 attribute
165  * @dst:  value to update
166  * @attr: netlink attribute with new value or null
167  * @mod:  pointer to bool for modification tracking
168  *
169  * Update bits in u32 value which are set in attribute's mask to values from
170  * attribute's value. Do nothing if @attr is null or the value wouldn't change;
171  * otherwise, set bool pointed to by @mod to true.
172  */
173 static inline void ethnl_update_bitfield32(u32 *dst, const struct nlattr *attr,
174 					   bool *mod)
175 {
176 	struct nla_bitfield32 change;
177 	u32 newval;
178 
179 	if (!attr)
180 		return;
181 	change = nla_get_bitfield32(attr);
182 	newval = (*dst & ~change.selector) | (change.value & change.selector);
183 	if (*dst == newval)
184 		return;
185 
186 	*dst = newval;
187 	*mod = true;
188 }
189 
190 /**
191  * ethnl_reply_header_size() - total size of reply header
192  *
193  * This is an upper estimate so that we do not need to hold RTNL lock longer
194  * than necessary (to prevent rename between size estimate and composing the
195  * message). Accounts only for device ifindex and name as those are the only
196  * attributes ethnl_fill_reply_header() puts into the reply header.
197  */
198 static inline unsigned int ethnl_reply_header_size(void)
199 {
200 	return nla_total_size(nla_total_size(sizeof(u32)) +
201 			      nla_total_size(IFNAMSIZ));
202 }
203 
204 /* GET request handling */
205 
206 /* Unified processing of GET requests uses two data structures: request info
207  * and reply data. Request info holds information parsed from client request
208  * and its stays constant through all request processing. Reply data holds data
209  * retrieved from ethtool_ops callbacks or other internal sources which is used
210  * to compose the reply. When processing a dump request, request info is filled
211  * only once (when the request message is parsed) but reply data is filled for
212  * each reply message.
213  *
214  * Both structures consist of part common for all request types (struct
215  * ethnl_req_info and struct ethnl_reply_data defined below) and optional
216  * parts specific for each request type. Common part always starts at offset 0.
217  */
218 
219 /**
220  * struct ethnl_req_info - base type of request information for GET requests
221  * @dev:   network device the request is for (may be null)
222  * @flags: request flags common for all request types
223  *
224  * This is a common base for request specific structures holding data from
225  * parsed userspace request. These always embed struct ethnl_req_info at
226  * zero offset.
227  */
228 struct ethnl_req_info {
229 	struct net_device	*dev;
230 	u32			flags;
231 };
232 
233 /**
234  * struct ethnl_reply_data - base type of reply data for GET requests
235  * @dev:       device for current reply message; in single shot requests it is
236  *             equal to &ethnl_req_info.dev; in dumps it's different for each
237  *             reply message
238  *
239  * This is a common base for request specific structures holding data for
240  * kernel reply message. These always embed struct ethnl_reply_data at zero
241  * offset.
242  */
243 struct ethnl_reply_data {
244 	struct net_device		*dev;
245 };
246 
247 static inline int ethnl_ops_begin(struct net_device *dev)
248 {
249 	if (dev && dev->ethtool_ops->begin)
250 		return dev->ethtool_ops->begin(dev);
251 	else
252 		return 0;
253 }
254 
255 static inline void ethnl_ops_complete(struct net_device *dev)
256 {
257 	if (dev && dev->ethtool_ops->complete)
258 		dev->ethtool_ops->complete(dev);
259 }
260 
261 /**
262  * struct ethnl_request_ops - unified handling of GET requests
263  * @request_cmd:      command id for request (GET)
264  * @reply_cmd:        command id for reply (GET_REPLY)
265  * @hdr_attr:         attribute type for request header
266  * @max_attr:         maximum (top level) attribute type
267  * @req_info_size:    size of request info
268  * @reply_data_size:  size of reply data
269  * @request_policy:   netlink policy for message contents
270  * @allow_nodev_do:   allow non-dump request with no device identification
271  * @parse_request:
272  *	Parse request except common header (struct ethnl_req_info). Common
273  *	header is already filled on entry, the rest up to @repdata_offset
274  *	is zero initialized. This callback should only modify type specific
275  *	request info by parsed attributes from request message.
276  * @prepare_data:
277  *	Retrieve and prepare data needed to compose a reply message. Calls to
278  *	ethtool_ops handlers are limited to this callback. Common reply data
279  *	(struct ethnl_reply_data) is filled on entry, type specific part after
280  *	it is zero initialized. This callback should only modify the type
281  *	specific part of reply data. Device identification from struct
282  *	ethnl_reply_data is to be used as for dump requests, it iterates
283  *	through network devices while dev member of struct ethnl_req_info
284  *	points to the device from client request.
285  * @reply_size:
286  *	Estimate reply message size. Returned value must be sufficient for
287  *	message payload without common reply header. The callback may returned
288  *	estimate higher than actual message size if exact calculation would
289  *	not be worth the saved memory space.
290  * @fill_reply:
291  *	Fill reply message payload (except for common header) from reply data.
292  *	The callback must not generate more payload than previously called
293  *	->reply_size() estimated.
294  * @cleanup_data:
295  *	Optional cleanup called when reply data is no longer needed. Can be
296  *	used e.g. to free any additional data structures outside the main
297  *	structure which were allocated by ->prepare_data(). When processing
298  *	dump requests, ->cleanup() is called for each message.
299  *
300  * Description of variable parts of GET request handling when using the
301  * unified infrastructure. When used, a pointer to an instance of this
302  * structure is to be added to &ethnl_default_requests array and generic
303  * handlers ethnl_default_doit(), ethnl_default_dumpit(),
304  * ethnl_default_start() and ethnl_default_done() used in @ethtool_genl_ops;
305  * ethnl_default_notify() can be used in @ethnl_notify_handlers to send
306  * notifications of the corresponding type.
307  */
308 struct ethnl_request_ops {
309 	u8			request_cmd;
310 	u8			reply_cmd;
311 	u16			hdr_attr;
312 	unsigned int		max_attr;
313 	unsigned int		req_info_size;
314 	unsigned int		reply_data_size;
315 	const struct nla_policy *request_policy;
316 	bool			allow_nodev_do;
317 
318 	int (*parse_request)(struct ethnl_req_info *req_info,
319 			     struct nlattr **tb,
320 			     struct netlink_ext_ack *extack);
321 	int (*prepare_data)(const struct ethnl_req_info *req_info,
322 			    struct ethnl_reply_data *reply_data,
323 			    struct genl_info *info);
324 	int (*reply_size)(const struct ethnl_req_info *req_info,
325 			  const struct ethnl_reply_data *reply_data);
326 	int (*fill_reply)(struct sk_buff *skb,
327 			  const struct ethnl_req_info *req_info,
328 			  const struct ethnl_reply_data *reply_data);
329 	void (*cleanup_data)(struct ethnl_reply_data *reply_data);
330 };
331 
332 /* request handlers */
333 
334 extern const struct ethnl_request_ops ethnl_strset_request_ops;
335 extern const struct ethnl_request_ops ethnl_linkinfo_request_ops;
336 extern const struct ethnl_request_ops ethnl_linkmodes_request_ops;
337 extern const struct ethnl_request_ops ethnl_linkstate_request_ops;
338 extern const struct ethnl_request_ops ethnl_debug_request_ops;
339 extern const struct ethnl_request_ops ethnl_wol_request_ops;
340 extern const struct ethnl_request_ops ethnl_features_request_ops;
341 extern const struct ethnl_request_ops ethnl_privflags_request_ops;
342 extern const struct ethnl_request_ops ethnl_rings_request_ops;
343 extern const struct ethnl_request_ops ethnl_channels_request_ops;
344 extern const struct ethnl_request_ops ethnl_coalesce_request_ops;
345 extern const struct ethnl_request_ops ethnl_pause_request_ops;
346 extern const struct ethnl_request_ops ethnl_eee_request_ops;
347 extern const struct ethnl_request_ops ethnl_tsinfo_request_ops;
348 
349 int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info);
350 int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info);
351 int ethnl_set_debug(struct sk_buff *skb, struct genl_info *info);
352 int ethnl_set_wol(struct sk_buff *skb, struct genl_info *info);
353 int ethnl_set_features(struct sk_buff *skb, struct genl_info *info);
354 int ethnl_set_privflags(struct sk_buff *skb, struct genl_info *info);
355 int ethnl_set_rings(struct sk_buff *skb, struct genl_info *info);
356 int ethnl_set_channels(struct sk_buff *skb, struct genl_info *info);
357 int ethnl_set_coalesce(struct sk_buff *skb, struct genl_info *info);
358 int ethnl_set_pause(struct sk_buff *skb, struct genl_info *info);
359 int ethnl_set_eee(struct sk_buff *skb, struct genl_info *info);
360 
361 #endif /* _NET_ETHTOOL_NETLINK_H */
362