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1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __NET_NETLINK_H
3 #define __NET_NETLINK_H
4 
5 #include <linux/types.h>
6 #include <linux/netlink.h>
7 #include <linux/jiffies.h>
8 #include <linux/in6.h>
9 
10 /* ========================================================================
11  *         Netlink Messages and Attributes Interface (As Seen On TV)
12  * ------------------------------------------------------------------------
13  *                          Messages Interface
14  * ------------------------------------------------------------------------
15  *
16  * Message Format:
17  *    <--- nlmsg_total_size(payload)  --->
18  *    <-- nlmsg_msg_size(payload) ->
19  *   +----------+- - -+-------------+- - -+-------- - -
20  *   | nlmsghdr | Pad |   Payload   | Pad | nlmsghdr
21  *   +----------+- - -+-------------+- - -+-------- - -
22  *   nlmsg_data(nlh)---^                   ^
23  *   nlmsg_next(nlh)-----------------------+
24  *
25  * Payload Format:
26  *    <---------------------- nlmsg_len(nlh) --------------------->
27  *    <------ hdrlen ------>       <- nlmsg_attrlen(nlh, hdrlen) ->
28  *   +----------------------+- - -+--------------------------------+
29  *   |     Family Header    | Pad |           Attributes           |
30  *   +----------------------+- - -+--------------------------------+
31  *   nlmsg_attrdata(nlh, hdrlen)---^
32  *
33  * Data Structures:
34  *   struct nlmsghdr			netlink message header
35  *
36  * Message Construction:
37  *   nlmsg_new()			create a new netlink message
38  *   nlmsg_put()			add a netlink message to an skb
39  *   nlmsg_put_answer()			callback based nlmsg_put()
40  *   nlmsg_end()			finalize netlink message
41  *   nlmsg_get_pos()			return current position in message
42  *   nlmsg_trim()			trim part of message
43  *   nlmsg_cancel()			cancel message construction
44  *   nlmsg_free()			free a netlink message
45  *
46  * Message Sending:
47  *   nlmsg_multicast()			multicast message to several groups
48  *   nlmsg_unicast()			unicast a message to a single socket
49  *   nlmsg_notify()			send notification message
50  *
51  * Message Length Calculations:
52  *   nlmsg_msg_size(payload)		length of message w/o padding
53  *   nlmsg_total_size(payload)		length of message w/ padding
54  *   nlmsg_padlen(payload)		length of padding at tail
55  *
56  * Message Payload Access:
57  *   nlmsg_data(nlh)			head of message payload
58  *   nlmsg_len(nlh)			length of message payload
59  *   nlmsg_attrdata(nlh, hdrlen)	head of attributes data
60  *   nlmsg_attrlen(nlh, hdrlen)		length of attributes data
61  *
62  * Message Parsing:
63  *   nlmsg_ok(nlh, remaining)		does nlh fit into remaining bytes?
64  *   nlmsg_next(nlh, remaining)		get next netlink message
65  *   nlmsg_parse()			parse attributes of a message
66  *   nlmsg_find_attr()			find an attribute in a message
67  *   nlmsg_for_each_msg()		loop over all messages
68  *   nlmsg_validate()			validate netlink message incl. attrs
69  *   nlmsg_for_each_attr()		loop over all attributes
70  *
71  * Misc:
72  *   nlmsg_report()			report back to application?
73  *
74  * ------------------------------------------------------------------------
75  *                          Attributes Interface
76  * ------------------------------------------------------------------------
77  *
78  * Attribute Format:
79  *    <------- nla_total_size(payload) ------->
80  *    <---- nla_attr_size(payload) ----->
81  *   +----------+- - -+- - - - - - - - - +- - -+-------- - -
82  *   |  Header  | Pad |     Payload      | Pad |  Header
83  *   +----------+- - -+- - - - - - - - - +- - -+-------- - -
84  *                     <- nla_len(nla) ->      ^
85  *   nla_data(nla)----^                        |
86  *   nla_next(nla)-----------------------------'
87  *
88  * Data Structures:
89  *   struct nlattr			netlink attribute header
90  *
91  * Attribute Construction:
92  *   nla_reserve(skb, type, len)	reserve room for an attribute
93  *   nla_reserve_nohdr(skb, len)	reserve room for an attribute w/o hdr
94  *   nla_put(skb, type, len, data)	add attribute to skb
95  *   nla_put_nohdr(skb, len, data)	add attribute w/o hdr
96  *   nla_append(skb, len, data)		append data to skb
97  *
98  * Attribute Construction for Basic Types:
99  *   nla_put_u8(skb, type, value)	add u8 attribute to skb
100  *   nla_put_u16(skb, type, value)	add u16 attribute to skb
101  *   nla_put_u32(skb, type, value)	add u32 attribute to skb
102  *   nla_put_u64_64bit(skb, type,
103  *                     value, padattr)	add u64 attribute to skb
104  *   nla_put_s8(skb, type, value)	add s8 attribute to skb
105  *   nla_put_s16(skb, type, value)	add s16 attribute to skb
106  *   nla_put_s32(skb, type, value)	add s32 attribute to skb
107  *   nla_put_s64(skb, type, value,
108  *               padattr)		add s64 attribute to skb
109  *   nla_put_string(skb, type, str)	add string attribute to skb
110  *   nla_put_flag(skb, type)		add flag attribute to skb
111  *   nla_put_msecs(skb, type, jiffies,
112  *                 padattr)		add msecs attribute to skb
113  *   nla_put_in_addr(skb, type, addr)	add IPv4 address attribute to skb
114  *   nla_put_in6_addr(skb, type, addr)	add IPv6 address attribute to skb
115  *
116  * Nested Attributes Construction:
117  *   nla_nest_start(skb, type)		start a nested attribute
118  *   nla_nest_end(skb, nla)		finalize a nested attribute
119  *   nla_nest_cancel(skb, nla)		cancel nested attribute construction
120  *
121  * Attribute Length Calculations:
122  *   nla_attr_size(payload)		length of attribute w/o padding
123  *   nla_total_size(payload)		length of attribute w/ padding
124  *   nla_padlen(payload)		length of padding
125  *
126  * Attribute Payload Access:
127  *   nla_data(nla)			head of attribute payload
128  *   nla_len(nla)			length of attribute payload
129  *
130  * Attribute Payload Access for Basic Types:
131  *   nla_get_u8(nla)			get payload for a u8 attribute
132  *   nla_get_u16(nla)			get payload for a u16 attribute
133  *   nla_get_u32(nla)			get payload for a u32 attribute
134  *   nla_get_u64(nla)			get payload for a u64 attribute
135  *   nla_get_s8(nla)			get payload for a s8 attribute
136  *   nla_get_s16(nla)			get payload for a s16 attribute
137  *   nla_get_s32(nla)			get payload for a s32 attribute
138  *   nla_get_s64(nla)			get payload for a s64 attribute
139  *   nla_get_flag(nla)			return 1 if flag is true
140  *   nla_get_msecs(nla)			get payload for a msecs attribute
141  *
142  * Attribute Misc:
143  *   nla_memcpy(dest, nla, count)	copy attribute into memory
144  *   nla_memcmp(nla, data, size)	compare attribute with memory area
145  *   nla_strscpy(dst, nla, size)	copy attribute to a sized string
146  *   nla_strcmp(nla, str)		compare attribute with string
147  *
148  * Attribute Parsing:
149  *   nla_ok(nla, remaining)		does nla fit into remaining bytes?
150  *   nla_next(nla, remaining)		get next netlink attribute
151  *   nla_validate()			validate a stream of attributes
152  *   nla_validate_nested()		validate a stream of nested attributes
153  *   nla_find()				find attribute in stream of attributes
154  *   nla_find_nested()			find attribute in nested attributes
155  *   nla_parse()			parse and validate stream of attrs
156  *   nla_parse_nested()			parse nested attributes
157  *   nla_for_each_attr()		loop over all attributes
158  *   nla_for_each_nested()		loop over the nested attributes
159  *=========================================================================
160  */
161 
162  /**
163   * Standard attribute types to specify validation policy
164   */
165 enum {
166 	NLA_UNSPEC,
167 	NLA_U8,
168 	NLA_U16,
169 	NLA_U32,
170 	NLA_U64,
171 	NLA_STRING,
172 	NLA_FLAG,
173 	NLA_MSECS,
174 	NLA_NESTED,
175 	NLA_NESTED_ARRAY,
176 	NLA_NUL_STRING,
177 	NLA_BINARY,
178 	NLA_S8,
179 	NLA_S16,
180 	NLA_S32,
181 	NLA_S64,
182 	NLA_BITFIELD32,
183 	NLA_REJECT,
184 	NLA_BE16,
185 	NLA_BE32,
186 	__NLA_TYPE_MAX,
187 };
188 
189 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
190 
191 struct netlink_range_validation {
192 	u64 min, max;
193 };
194 
195 struct netlink_range_validation_signed {
196 	s64 min, max;
197 };
198 
199 enum nla_policy_validation {
200 	NLA_VALIDATE_NONE,
201 	NLA_VALIDATE_RANGE,
202 	NLA_VALIDATE_RANGE_WARN_TOO_LONG,
203 	NLA_VALIDATE_MIN,
204 	NLA_VALIDATE_MAX,
205 	NLA_VALIDATE_MASK,
206 	NLA_VALIDATE_RANGE_PTR,
207 	NLA_VALIDATE_FUNCTION,
208 };
209 
210 /**
211  * struct nla_policy - attribute validation policy
212  * @type: Type of attribute or NLA_UNSPEC
213  * @validation_type: type of attribute validation done in addition to
214  *	type-specific validation (e.g. range, function call), see
215  *	&enum nla_policy_validation
216  * @len: Type specific length of payload
217  *
218  * Policies are defined as arrays of this struct, the array must be
219  * accessible by attribute type up to the highest identifier to be expected.
220  *
221  * Meaning of `len' field:
222  *    NLA_STRING           Maximum length of string
223  *    NLA_NUL_STRING       Maximum length of string (excluding NUL)
224  *    NLA_FLAG             Unused
225  *    NLA_BINARY           Maximum length of attribute payload
226  *                         (but see also below with the validation type)
227  *    NLA_NESTED,
228  *    NLA_NESTED_ARRAY     Length verification is done by checking len of
229  *                         nested header (or empty); len field is used if
230  *                         nested_policy is also used, for the max attr
231  *                         number in the nested policy.
232  *    NLA_U8, NLA_U16,
233  *    NLA_U32, NLA_U64,
234  *    NLA_S8, NLA_S16,
235  *    NLA_S32, NLA_S64,
236  *    NLA_BE16, NLA_BE32,
237  *    NLA_MSECS            Leaving the length field zero will verify the
238  *                         given type fits, using it verifies minimum length
239  *                         just like "All other"
240  *    NLA_BITFIELD32       Unused
241  *    NLA_REJECT           Unused
242  *    All other            Minimum length of attribute payload
243  *
244  * Meaning of validation union:
245  *    NLA_BITFIELD32       This is a 32-bit bitmap/bitselector attribute and
246  *                         `bitfield32_valid' is the u32 value of valid flags
247  *    NLA_REJECT           This attribute is always rejected and `reject_message'
248  *                         may point to a string to report as the error instead
249  *                         of the generic one in extended ACK.
250  *    NLA_NESTED           `nested_policy' to a nested policy to validate, must
251  *                         also set `len' to the max attribute number. Use the
252  *                         provided NLA_POLICY_NESTED() macro.
253  *                         Note that nla_parse() will validate, but of course not
254  *                         parse, the nested sub-policies.
255  *    NLA_NESTED_ARRAY     `nested_policy' points to a nested policy to validate,
256  *                         must also set `len' to the max attribute number. Use
257  *                         the provided NLA_POLICY_NESTED_ARRAY() macro.
258  *                         The difference to NLA_NESTED is the structure:
259  *                         NLA_NESTED has the nested attributes directly inside
260  *                         while an array has the nested attributes at another
261  *                         level down and the attribute types directly in the
262  *                         nesting don't matter.
263  *    NLA_U8,
264  *    NLA_U16,
265  *    NLA_U32,
266  *    NLA_U64,
267  *    NLA_BE16,
268  *    NLA_BE32,
269  *    NLA_S8,
270  *    NLA_S16,
271  *    NLA_S32,
272  *    NLA_S64              The `min' and `max' fields are used depending on the
273  *                         validation_type field, if that is min/max/range then
274  *                         the min, max or both are used (respectively) to check
275  *                         the value of the integer attribute.
276  *                         Note that in the interest of code simplicity and
277  *                         struct size both limits are s16, so you cannot
278  *                         enforce a range that doesn't fall within the range
279  *                         of s16 - do that as usual in the code instead.
280  *                         Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
281  *                         NLA_POLICY_RANGE() macros.
282  *    NLA_U8,
283  *    NLA_U16,
284  *    NLA_U32,
285  *    NLA_U64              If the validation_type field instead is set to
286  *                         NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
287  *                         to a struct netlink_range_validation that indicates
288  *                         the min/max values.
289  *                         Use NLA_POLICY_FULL_RANGE().
290  *    NLA_S8,
291  *    NLA_S16,
292  *    NLA_S32,
293  *    NLA_S64              If the validation_type field instead is set to
294  *                         NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
295  *                         pointer to a struct netlink_range_validation_signed
296  *                         that indicates the min/max values.
297  *                         Use NLA_POLICY_FULL_RANGE_SIGNED().
298  *
299  *    NLA_BINARY           If the validation type is like the ones for integers
300  *                         above, then the min/max length (not value like for
301  *                         integers) of the attribute is enforced.
302  *
303  *    All other            Unused - but note that it's a union
304  *
305  * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
306  *    NLA_BINARY           Validation function called for the attribute.
307  *    All other            Unused - but note that it's a union
308  *
309  * Example:
310  *
311  * static const u32 myvalidflags = 0xff231023;
312  *
313  * static const struct nla_policy my_policy[ATTR_MAX+1] = {
314  * 	[ATTR_FOO] = { .type = NLA_U16 },
315  *	[ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
316  *	[ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)),
317  *	[ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
318  * };
319  */
320 struct nla_policy {
321 	u8		type;
322 	u8		validation_type;
323 	u16		len;
324 	union {
325 		/**
326 		 * @strict_start_type: first attribute to validate strictly
327 		 *
328 		 * This entry is special, and used for the attribute at index 0
329 		 * only, and specifies special data about the policy, namely it
330 		 * specifies the "boundary type" where strict length validation
331 		 * starts for any attribute types >= this value, also, strict
332 		 * nesting validation starts here.
333 		 *
334 		 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
335 		 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to
336 		 * get the previous pure { .len = xyz } behaviour. The advantage
337 		 * of this is that types not specified in the policy will be
338 		 * rejected.
339 		 *
340 		 * For completely new families it should be set to 1 so that the
341 		 * validation is enforced for all attributes. For existing ones
342 		 * it should be set at least when new attributes are added to
343 		 * the enum used by the policy, and be set to the new value that
344 		 * was added to enforce strict validation from thereon.
345 		 */
346 		u16 strict_start_type;
347 
348 		/* private: use NLA_POLICY_*() to set */
349 		const u32 bitfield32_valid;
350 		const u32 mask;
351 		const char *reject_message;
352 		const struct nla_policy *nested_policy;
353 		struct netlink_range_validation *range;
354 		struct netlink_range_validation_signed *range_signed;
355 		struct {
356 			s16 min, max;
357 		};
358 		int (*validate)(const struct nlattr *attr,
359 				struct netlink_ext_ack *extack);
360 	};
361 };
362 
363 #define NLA_POLICY_ETH_ADDR		NLA_POLICY_EXACT_LEN(ETH_ALEN)
364 #define NLA_POLICY_ETH_ADDR_COMPAT	NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
365 
366 #define _NLA_POLICY_NESTED(maxattr, policy) \
367 	{ .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
368 #define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
369 	{ .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
370 #define NLA_POLICY_NESTED(policy) \
371 	_NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
372 #define NLA_POLICY_NESTED_ARRAY(policy) \
373 	_NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
374 #define NLA_POLICY_BITFIELD32(valid) \
375 	{ .type = NLA_BITFIELD32, .bitfield32_valid = valid }
376 
377 #define __NLA_IS_UINT_TYPE(tp)						\
378 	(tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || tp == NLA_U64)
379 #define __NLA_IS_SINT_TYPE(tp)						\
380 	(tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64)
381 #define __NLA_IS_BEINT_TYPE(tp)						\
382 	(tp == NLA_BE16 || tp == NLA_BE32)
383 
384 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
385 #define NLA_ENSURE_UINT_TYPE(tp)			\
386 	(__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
387 #define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp)		\
388 	(__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) ||	\
389 		      tp == NLA_MSECS ||		\
390 		      tp == NLA_BINARY) + tp)
391 #define NLA_ENSURE_SINT_TYPE(tp)			\
392 	(__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
393 #define NLA_ENSURE_INT_OR_BINARY_TYPE(tp)		\
394 	(__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) ||		\
395 		      __NLA_IS_SINT_TYPE(tp) ||		\
396 		      __NLA_IS_BEINT_TYPE(tp) ||	\
397 		      tp == NLA_MSECS ||		\
398 		      tp == NLA_BINARY) + tp)
399 #define NLA_ENSURE_NO_VALIDATION_PTR(tp)		\
400 	(__NLA_ENSURE(tp != NLA_BITFIELD32 &&		\
401 		      tp != NLA_REJECT &&		\
402 		      tp != NLA_NESTED &&		\
403 		      tp != NLA_NESTED_ARRAY) + tp)
404 #define NLA_ENSURE_BEINT_TYPE(tp)			\
405 	(__NLA_ENSURE(__NLA_IS_BEINT_TYPE(tp)) + tp)
406 
407 #define NLA_POLICY_RANGE(tp, _min, _max) {		\
408 	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
409 	.validation_type = NLA_VALIDATE_RANGE,		\
410 	.min = _min,					\
411 	.max = _max					\
412 }
413 
414 #define NLA_POLICY_FULL_RANGE(tp, _range) {		\
415 	.type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp),	\
416 	.validation_type = NLA_VALIDATE_RANGE_PTR,	\
417 	.range = _range,				\
418 }
419 
420 #define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) {	\
421 	.type = NLA_ENSURE_SINT_TYPE(tp),		\
422 	.validation_type = NLA_VALIDATE_RANGE_PTR,	\
423 	.range_signed = _range,				\
424 }
425 
426 #define NLA_POLICY_MIN(tp, _min) {			\
427 	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
428 	.validation_type = NLA_VALIDATE_MIN,		\
429 	.min = _min,					\
430 }
431 
432 #define NLA_POLICY_MAX(tp, _max) {			\
433 	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
434 	.validation_type = NLA_VALIDATE_MAX,		\
435 	.max = _max,					\
436 }
437 
438 #define NLA_POLICY_MASK(tp, _mask) {			\
439 	.type = NLA_ENSURE_UINT_TYPE(tp),		\
440 	.validation_type = NLA_VALIDATE_MASK,		\
441 	.mask = _mask,					\
442 }
443 
444 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) {		\
445 	.type = NLA_ENSURE_NO_VALIDATION_PTR(tp),	\
446 	.validation_type = NLA_VALIDATE_FUNCTION,	\
447 	.validate = fn,					\
448 	.len = __VA_ARGS__ + 0,				\
449 }
450 
451 #define NLA_POLICY_EXACT_LEN(_len)	NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
452 #define NLA_POLICY_EXACT_LEN_WARN(_len) {			\
453 	.type = NLA_BINARY,					\
454 	.validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG,	\
455 	.min = _len,						\
456 	.max = _len						\
457 }
458 #define NLA_POLICY_MIN_LEN(_len)	NLA_POLICY_MIN(NLA_BINARY, _len)
459 
460 /**
461  * struct nl_info - netlink source information
462  * @nlh: Netlink message header of original request
463  * @nl_net: Network namespace
464  * @portid: Netlink PORTID of requesting application
465  * @skip_notify: Skip netlink notifications to user space
466  * @skip_notify_kernel: Skip selected in-kernel notifications
467  */
468 struct nl_info {
469 	struct nlmsghdr		*nlh;
470 	struct net		*nl_net;
471 	u32			portid;
472 	u8			skip_notify:1,
473 				skip_notify_kernel:1;
474 };
475 
476 /**
477  * enum netlink_validation - netlink message/attribute validation levels
478  * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
479  *	extra data at the end of the message, attributes being longer than
480  *	they should be, or unknown attributes being present.
481  * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
482  * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
483  *	this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
484  * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
485  *	This can safely be set by the kernel when the given policy has no
486  *	NLA_UNSPEC anymore, and can thus be used to ensure policy entries
487  *	are enforced going forward.
488  * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
489  *	U8, U16, U32 must have exact size, etc.)
490  * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
491  *	and unset for other policies.
492  */
493 enum netlink_validation {
494 	NL_VALIDATE_LIBERAL = 0,
495 	NL_VALIDATE_TRAILING = BIT(0),
496 	NL_VALIDATE_MAXTYPE = BIT(1),
497 	NL_VALIDATE_UNSPEC = BIT(2),
498 	NL_VALIDATE_STRICT_ATTRS = BIT(3),
499 	NL_VALIDATE_NESTED = BIT(4),
500 };
501 
502 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
503 				       NL_VALIDATE_MAXTYPE)
504 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
505 			    NL_VALIDATE_MAXTYPE |\
506 			    NL_VALIDATE_UNSPEC |\
507 			    NL_VALIDATE_STRICT_ATTRS |\
508 			    NL_VALIDATE_NESTED)
509 
510 int netlink_rcv_skb(struct sk_buff *skb,
511 		    int (*cb)(struct sk_buff *, struct nlmsghdr *,
512 			      struct netlink_ext_ack *));
513 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
514 		 unsigned int group, int report, gfp_t flags);
515 
516 int __nla_validate(const struct nlattr *head, int len, int maxtype,
517 		   const struct nla_policy *policy, unsigned int validate,
518 		   struct netlink_ext_ack *extack);
519 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
520 		int len, const struct nla_policy *policy, unsigned int validate,
521 		struct netlink_ext_ack *extack);
522 int nla_policy_len(const struct nla_policy *, int);
523 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
524 ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
525 char *nla_strdup(const struct nlattr *nla, gfp_t flags);
526 int nla_memcpy(void *dest, const struct nlattr *src, int count);
527 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
528 int nla_strcmp(const struct nlattr *nla, const char *str);
529 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
530 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
531 				   int attrlen, int padattr);
532 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
533 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
534 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
535 				 int attrlen, int padattr);
536 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
537 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
538 	       const void *data);
539 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
540 		     const void *data, int padattr);
541 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
542 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
543 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
544 		  const void *data, int padattr);
545 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
546 int nla_append(struct sk_buff *skb, int attrlen, const void *data);
547 
548 /**************************************************************************
549  * Netlink Messages
550  **************************************************************************/
551 
552 /**
553  * nlmsg_msg_size - length of netlink message not including padding
554  * @payload: length of message payload
555  */
nlmsg_msg_size(int payload)556 static inline int nlmsg_msg_size(int payload)
557 {
558 	return NLMSG_HDRLEN + payload;
559 }
560 
561 /**
562  * nlmsg_total_size - length of netlink message including padding
563  * @payload: length of message payload
564  */
nlmsg_total_size(int payload)565 static inline int nlmsg_total_size(int payload)
566 {
567 	return NLMSG_ALIGN(nlmsg_msg_size(payload));
568 }
569 
570 /**
571  * nlmsg_padlen - length of padding at the message's tail
572  * @payload: length of message payload
573  */
nlmsg_padlen(int payload)574 static inline int nlmsg_padlen(int payload)
575 {
576 	return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
577 }
578 
579 /**
580  * nlmsg_data - head of message payload
581  * @nlh: netlink message header
582  */
nlmsg_data(const struct nlmsghdr * nlh)583 static inline void *nlmsg_data(const struct nlmsghdr *nlh)
584 {
585 	return (unsigned char *) nlh + NLMSG_HDRLEN;
586 }
587 
588 /**
589  * nlmsg_len - length of message payload
590  * @nlh: netlink message header
591  */
nlmsg_len(const struct nlmsghdr * nlh)592 static inline int nlmsg_len(const struct nlmsghdr *nlh)
593 {
594 	return nlh->nlmsg_len - NLMSG_HDRLEN;
595 }
596 
597 /**
598  * nlmsg_attrdata - head of attributes data
599  * @nlh: netlink message header
600  * @hdrlen: length of family specific header
601  */
nlmsg_attrdata(const struct nlmsghdr * nlh,int hdrlen)602 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
603 					    int hdrlen)
604 {
605 	unsigned char *data = nlmsg_data(nlh);
606 	return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
607 }
608 
609 /**
610  * nlmsg_attrlen - length of attributes data
611  * @nlh: netlink message header
612  * @hdrlen: length of family specific header
613  */
nlmsg_attrlen(const struct nlmsghdr * nlh,int hdrlen)614 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
615 {
616 	return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
617 }
618 
619 /**
620  * nlmsg_ok - check if the netlink message fits into the remaining bytes
621  * @nlh: netlink message header
622  * @remaining: number of bytes remaining in message stream
623  */
nlmsg_ok(const struct nlmsghdr * nlh,int remaining)624 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
625 {
626 	return (remaining >= (int) sizeof(struct nlmsghdr) &&
627 		nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
628 		nlh->nlmsg_len <= remaining);
629 }
630 
631 /**
632  * nlmsg_next - next netlink message in message stream
633  * @nlh: netlink message header
634  * @remaining: number of bytes remaining in message stream
635  *
636  * Returns the next netlink message in the message stream and
637  * decrements remaining by the size of the current message.
638  */
639 static inline struct nlmsghdr *
nlmsg_next(const struct nlmsghdr * nlh,int * remaining)640 nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
641 {
642 	int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
643 
644 	*remaining -= totlen;
645 
646 	return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
647 }
648 
649 /**
650  * nla_parse - Parse a stream of attributes into a tb buffer
651  * @tb: destination array with maxtype+1 elements
652  * @maxtype: maximum attribute type to be expected
653  * @head: head of attribute stream
654  * @len: length of attribute stream
655  * @policy: validation policy
656  * @extack: extended ACK pointer
657  *
658  * Parses a stream of attributes and stores a pointer to each attribute in
659  * the tb array accessible via the attribute type. Attributes with a type
660  * exceeding maxtype will be rejected, policy must be specified, attributes
661  * will be validated in the strictest way possible.
662  *
663  * Returns 0 on success or a negative error code.
664  */
nla_parse(struct nlattr ** tb,int maxtype,const struct nlattr * head,int len,const struct nla_policy * policy,struct netlink_ext_ack * extack)665 static inline int nla_parse(struct nlattr **tb, int maxtype,
666 			    const struct nlattr *head, int len,
667 			    const struct nla_policy *policy,
668 			    struct netlink_ext_ack *extack)
669 {
670 	return __nla_parse(tb, maxtype, head, len, policy,
671 			   NL_VALIDATE_STRICT, extack);
672 }
673 
674 /**
675  * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
676  * @tb: destination array with maxtype+1 elements
677  * @maxtype: maximum attribute type to be expected
678  * @head: head of attribute stream
679  * @len: length of attribute stream
680  * @policy: validation policy
681  * @extack: extended ACK pointer
682  *
683  * Parses a stream of attributes and stores a pointer to each attribute in
684  * the tb array accessible via the attribute type. Attributes with a type
685  * exceeding maxtype will be ignored and attributes from the policy are not
686  * always strictly validated (only for new attributes).
687  *
688  * Returns 0 on success or a negative error code.
689  */
nla_parse_deprecated(struct nlattr ** tb,int maxtype,const struct nlattr * head,int len,const struct nla_policy * policy,struct netlink_ext_ack * extack)690 static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
691 				       const struct nlattr *head, int len,
692 				       const struct nla_policy *policy,
693 				       struct netlink_ext_ack *extack)
694 {
695 	return __nla_parse(tb, maxtype, head, len, policy,
696 			   NL_VALIDATE_LIBERAL, extack);
697 }
698 
699 /**
700  * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
701  * @tb: destination array with maxtype+1 elements
702  * @maxtype: maximum attribute type to be expected
703  * @head: head of attribute stream
704  * @len: length of attribute stream
705  * @policy: validation policy
706  * @extack: extended ACK pointer
707  *
708  * Parses a stream of attributes and stores a pointer to each attribute in
709  * the tb array accessible via the attribute type. Attributes with a type
710  * exceeding maxtype will be rejected as well as trailing data, but the
711  * policy is not completely strictly validated (only for new attributes).
712  *
713  * Returns 0 on success or a negative error code.
714  */
nla_parse_deprecated_strict(struct nlattr ** tb,int maxtype,const struct nlattr * head,int len,const struct nla_policy * policy,struct netlink_ext_ack * extack)715 static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
716 					      const struct nlattr *head,
717 					      int len,
718 					      const struct nla_policy *policy,
719 					      struct netlink_ext_ack *extack)
720 {
721 	return __nla_parse(tb, maxtype, head, len, policy,
722 			   NL_VALIDATE_DEPRECATED_STRICT, extack);
723 }
724 
725 /**
726  * __nlmsg_parse - parse attributes of a netlink message
727  * @nlh: netlink message header
728  * @hdrlen: length of family specific header
729  * @tb: destination array with maxtype+1 elements
730  * @maxtype: maximum attribute type to be expected
731  * @policy: validation policy
732  * @validate: validation strictness
733  * @extack: extended ACK report struct
734  *
735  * See nla_parse()
736  */
__nlmsg_parse(const struct nlmsghdr * nlh,int hdrlen,struct nlattr * tb[],int maxtype,const struct nla_policy * policy,unsigned int validate,struct netlink_ext_ack * extack)737 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
738 				struct nlattr *tb[], int maxtype,
739 				const struct nla_policy *policy,
740 				unsigned int validate,
741 				struct netlink_ext_ack *extack)
742 {
743 	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
744 		NL_SET_ERR_MSG(extack, "Invalid header length");
745 		return -EINVAL;
746 	}
747 
748 	return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
749 			   nlmsg_attrlen(nlh, hdrlen), policy, validate,
750 			   extack);
751 }
752 
753 /**
754  * nlmsg_parse - parse attributes of a netlink message
755  * @nlh: netlink message header
756  * @hdrlen: length of family specific header
757  * @tb: destination array with maxtype+1 elements
758  * @maxtype: maximum attribute type to be expected
759  * @policy: validation policy
760  * @extack: extended ACK report struct
761  *
762  * See nla_parse()
763  */
nlmsg_parse(const struct nlmsghdr * nlh,int hdrlen,struct nlattr * tb[],int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)764 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
765 			      struct nlattr *tb[], int maxtype,
766 			      const struct nla_policy *policy,
767 			      struct netlink_ext_ack *extack)
768 {
769 	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
770 			     NL_VALIDATE_STRICT, extack);
771 }
772 
773 /**
774  * nlmsg_parse_deprecated - parse attributes of a netlink message
775  * @nlh: netlink message header
776  * @hdrlen: length of family specific header
777  * @tb: destination array with maxtype+1 elements
778  * @maxtype: maximum attribute type to be expected
779  * @policy: validation policy
780  * @extack: extended ACK report struct
781  *
782  * See nla_parse_deprecated()
783  */
nlmsg_parse_deprecated(const struct nlmsghdr * nlh,int hdrlen,struct nlattr * tb[],int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)784 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
785 					 struct nlattr *tb[], int maxtype,
786 					 const struct nla_policy *policy,
787 					 struct netlink_ext_ack *extack)
788 {
789 	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
790 			     NL_VALIDATE_LIBERAL, extack);
791 }
792 
793 /**
794  * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
795  * @nlh: netlink message header
796  * @hdrlen: length of family specific header
797  * @tb: destination array with maxtype+1 elements
798  * @maxtype: maximum attribute type to be expected
799  * @policy: validation policy
800  * @extack: extended ACK report struct
801  *
802  * See nla_parse_deprecated_strict()
803  */
804 static inline int
nlmsg_parse_deprecated_strict(const struct nlmsghdr * nlh,int hdrlen,struct nlattr * tb[],int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)805 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
806 			      struct nlattr *tb[], int maxtype,
807 			      const struct nla_policy *policy,
808 			      struct netlink_ext_ack *extack)
809 {
810 	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
811 			     NL_VALIDATE_DEPRECATED_STRICT, extack);
812 }
813 
814 /**
815  * nlmsg_find_attr - find a specific attribute in a netlink message
816  * @nlh: netlink message header
817  * @hdrlen: length of familiy specific header
818  * @attrtype: type of attribute to look for
819  *
820  * Returns the first attribute which matches the specified type.
821  */
nlmsg_find_attr(const struct nlmsghdr * nlh,int hdrlen,int attrtype)822 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
823 					     int hdrlen, int attrtype)
824 {
825 	return nla_find(nlmsg_attrdata(nlh, hdrlen),
826 			nlmsg_attrlen(nlh, hdrlen), attrtype);
827 }
828 
829 /**
830  * nla_validate_deprecated - Validate a stream of attributes
831  * @head: head of attribute stream
832  * @len: length of attribute stream
833  * @maxtype: maximum attribute type to be expected
834  * @policy: validation policy
835  * @extack: extended ACK report struct
836  *
837  * Validates all attributes in the specified attribute stream against the
838  * specified policy. Validation is done in liberal mode.
839  * See documenation of struct nla_policy for more details.
840  *
841  * Returns 0 on success or a negative error code.
842  */
nla_validate_deprecated(const struct nlattr * head,int len,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)843 static inline int nla_validate_deprecated(const struct nlattr *head, int len,
844 					  int maxtype,
845 					  const struct nla_policy *policy,
846 					  struct netlink_ext_ack *extack)
847 {
848 	return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
849 			      extack);
850 }
851 
852 /**
853  * nla_validate - Validate a stream of attributes
854  * @head: head of attribute stream
855  * @len: length of attribute stream
856  * @maxtype: maximum attribute type to be expected
857  * @policy: validation policy
858  * @extack: extended ACK report struct
859  *
860  * Validates all attributes in the specified attribute stream against the
861  * specified policy. Validation is done in strict mode.
862  * See documenation of struct nla_policy for more details.
863  *
864  * Returns 0 on success or a negative error code.
865  */
nla_validate(const struct nlattr * head,int len,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)866 static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
867 			       const struct nla_policy *policy,
868 			       struct netlink_ext_ack *extack)
869 {
870 	return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
871 			      extack);
872 }
873 
874 /**
875  * nlmsg_validate_deprecated - validate a netlink message including attributes
876  * @nlh: netlinket message header
877  * @hdrlen: length of familiy specific header
878  * @maxtype: maximum attribute type to be expected
879  * @policy: validation policy
880  * @extack: extended ACK report struct
881  */
nlmsg_validate_deprecated(const struct nlmsghdr * nlh,int hdrlen,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)882 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
883 					    int hdrlen, int maxtype,
884 					    const struct nla_policy *policy,
885 					    struct netlink_ext_ack *extack)
886 {
887 	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
888 		return -EINVAL;
889 
890 	return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
891 			      nlmsg_attrlen(nlh, hdrlen), maxtype,
892 			      policy, NL_VALIDATE_LIBERAL, extack);
893 }
894 
895 
896 
897 /**
898  * nlmsg_report - need to report back to application?
899  * @nlh: netlink message header
900  *
901  * Returns 1 if a report back to the application is requested.
902  */
nlmsg_report(const struct nlmsghdr * nlh)903 static inline int nlmsg_report(const struct nlmsghdr *nlh)
904 {
905 	return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
906 }
907 
908 /**
909  * nlmsg_for_each_attr - iterate over a stream of attributes
910  * @pos: loop counter, set to current attribute
911  * @nlh: netlink message header
912  * @hdrlen: length of familiy specific header
913  * @rem: initialized to len, holds bytes currently remaining in stream
914  */
915 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
916 	nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
917 			  nlmsg_attrlen(nlh, hdrlen), rem)
918 
919 /**
920  * nlmsg_put - Add a new netlink message to an skb
921  * @skb: socket buffer to store message in
922  * @portid: netlink PORTID of requesting application
923  * @seq: sequence number of message
924  * @type: message type
925  * @payload: length of message payload
926  * @flags: message flags
927  *
928  * Returns NULL if the tailroom of the skb is insufficient to store
929  * the message header and payload.
930  */
nlmsg_put(struct sk_buff * skb,u32 portid,u32 seq,int type,int payload,int flags)931 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
932 					 int type, int payload, int flags)
933 {
934 	if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
935 		return NULL;
936 
937 	return __nlmsg_put(skb, portid, seq, type, payload, flags);
938 }
939 
940 /**
941  * nlmsg_append - Add more data to a nlmsg in a skb
942  * @skb: socket buffer to store message in
943  * @size: length of message payload
944  *
945  * Append data to an existing nlmsg, used when constructing a message
946  * with multiple fixed-format headers (which is rare).
947  * Returns NULL if the tailroom of the skb is insufficient to store
948  * the extra payload.
949  */
nlmsg_append(struct sk_buff * skb,u32 size)950 static inline void *nlmsg_append(struct sk_buff *skb, u32 size)
951 {
952 	if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size)))
953 		return NULL;
954 
955 	if (NLMSG_ALIGN(size) - size)
956 		memset(skb_tail_pointer(skb) + size, 0,
957 		       NLMSG_ALIGN(size) - size);
958 	return __skb_put(skb, NLMSG_ALIGN(size));
959 }
960 
961 /**
962  * nlmsg_put_answer - Add a new callback based netlink message to an skb
963  * @skb: socket buffer to store message in
964  * @cb: netlink callback
965  * @type: message type
966  * @payload: length of message payload
967  * @flags: message flags
968  *
969  * Returns NULL if the tailroom of the skb is insufficient to store
970  * the message header and payload.
971  */
nlmsg_put_answer(struct sk_buff * skb,struct netlink_callback * cb,int type,int payload,int flags)972 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
973 						struct netlink_callback *cb,
974 						int type, int payload,
975 						int flags)
976 {
977 	return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
978 			 type, payload, flags);
979 }
980 
981 /**
982  * nlmsg_new - Allocate a new netlink message
983  * @payload: size of the message payload
984  * @flags: the type of memory to allocate.
985  *
986  * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
987  * and a good default is needed.
988  */
nlmsg_new(size_t payload,gfp_t flags)989 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
990 {
991 	return alloc_skb(nlmsg_total_size(payload), flags);
992 }
993 
994 /**
995  * nlmsg_end - Finalize a netlink message
996  * @skb: socket buffer the message is stored in
997  * @nlh: netlink message header
998  *
999  * Corrects the netlink message header to include the appeneded
1000  * attributes. Only necessary if attributes have been added to
1001  * the message.
1002  */
nlmsg_end(struct sk_buff * skb,struct nlmsghdr * nlh)1003 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
1004 {
1005 	nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
1006 }
1007 
1008 /**
1009  * nlmsg_get_pos - return current position in netlink message
1010  * @skb: socket buffer the message is stored in
1011  *
1012  * Returns a pointer to the current tail of the message.
1013  */
nlmsg_get_pos(struct sk_buff * skb)1014 static inline void *nlmsg_get_pos(struct sk_buff *skb)
1015 {
1016 	return skb_tail_pointer(skb);
1017 }
1018 
1019 /**
1020  * nlmsg_trim - Trim message to a mark
1021  * @skb: socket buffer the message is stored in
1022  * @mark: mark to trim to
1023  *
1024  * Trims the message to the provided mark.
1025  */
nlmsg_trim(struct sk_buff * skb,const void * mark)1026 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1027 {
1028 	if (mark) {
1029 		WARN_ON((unsigned char *) mark < skb->data);
1030 		skb_trim(skb, (unsigned char *) mark - skb->data);
1031 	}
1032 }
1033 
1034 /**
1035  * nlmsg_cancel - Cancel construction of a netlink message
1036  * @skb: socket buffer the message is stored in
1037  * @nlh: netlink message header
1038  *
1039  * Removes the complete netlink message including all
1040  * attributes from the socket buffer again.
1041  */
nlmsg_cancel(struct sk_buff * skb,struct nlmsghdr * nlh)1042 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1043 {
1044 	nlmsg_trim(skb, nlh);
1045 }
1046 
1047 /**
1048  * nlmsg_free - free a netlink message
1049  * @skb: socket buffer of netlink message
1050  */
nlmsg_free(struct sk_buff * skb)1051 static inline void nlmsg_free(struct sk_buff *skb)
1052 {
1053 	kfree_skb(skb);
1054 }
1055 
1056 /**
1057  * nlmsg_multicast - multicast a netlink message
1058  * @sk: netlink socket to spread messages to
1059  * @skb: netlink message as socket buffer
1060  * @portid: own netlink portid to avoid sending to yourself
1061  * @group: multicast group id
1062  * @flags: allocation flags
1063  */
nlmsg_multicast(struct sock * sk,struct sk_buff * skb,u32 portid,unsigned int group,gfp_t flags)1064 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1065 				  u32 portid, unsigned int group, gfp_t flags)
1066 {
1067 	int err;
1068 
1069 	NETLINK_CB(skb).dst_group = group;
1070 
1071 	err = netlink_broadcast(sk, skb, portid, group, flags);
1072 	if (err > 0)
1073 		err = 0;
1074 
1075 	return err;
1076 }
1077 
1078 /**
1079  * nlmsg_unicast - unicast a netlink message
1080  * @sk: netlink socket to spread message to
1081  * @skb: netlink message as socket buffer
1082  * @portid: netlink portid of the destination socket
1083  */
nlmsg_unicast(struct sock * sk,struct sk_buff * skb,u32 portid)1084 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1085 {
1086 	int err;
1087 
1088 	err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1089 	if (err > 0)
1090 		err = 0;
1091 
1092 	return err;
1093 }
1094 
1095 /**
1096  * nlmsg_for_each_msg - iterate over a stream of messages
1097  * @pos: loop counter, set to current message
1098  * @head: head of message stream
1099  * @len: length of message stream
1100  * @rem: initialized to len, holds bytes currently remaining in stream
1101  */
1102 #define nlmsg_for_each_msg(pos, head, len, rem) \
1103 	for (pos = head, rem = len; \
1104 	     nlmsg_ok(pos, rem); \
1105 	     pos = nlmsg_next(pos, &(rem)))
1106 
1107 /**
1108  * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1109  * @cb: netlink callback structure that stores the sequence number
1110  * @nlh: netlink message header to write the flag to
1111  *
1112  * This function checks if the sequence (generation) number changed during dump
1113  * and if it did, advertises it in the netlink message header.
1114  *
1115  * The correct way to use it is to set cb->seq to the generation counter when
1116  * all locks for dumping have been acquired, and then call this function for
1117  * each message that is generated.
1118  *
1119  * Note that due to initialisation concerns, 0 is an invalid sequence number
1120  * and must not be used by code that uses this functionality.
1121  */
1122 static inline void
nl_dump_check_consistent(struct netlink_callback * cb,struct nlmsghdr * nlh)1123 nl_dump_check_consistent(struct netlink_callback *cb,
1124 			 struct nlmsghdr *nlh)
1125 {
1126 	if (cb->prev_seq && cb->seq != cb->prev_seq)
1127 		nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1128 	cb->prev_seq = cb->seq;
1129 }
1130 
1131 /**************************************************************************
1132  * Netlink Attributes
1133  **************************************************************************/
1134 
1135 /**
1136  * nla_attr_size - length of attribute not including padding
1137  * @payload: length of payload
1138  */
nla_attr_size(int payload)1139 static inline int nla_attr_size(int payload)
1140 {
1141 	return NLA_HDRLEN + payload;
1142 }
1143 
1144 /**
1145  * nla_total_size - total length of attribute including padding
1146  * @payload: length of payload
1147  */
nla_total_size(int payload)1148 static inline int nla_total_size(int payload)
1149 {
1150 	return NLA_ALIGN(nla_attr_size(payload));
1151 }
1152 
1153 /**
1154  * nla_padlen - length of padding at the tail of attribute
1155  * @payload: length of payload
1156  */
nla_padlen(int payload)1157 static inline int nla_padlen(int payload)
1158 {
1159 	return nla_total_size(payload) - nla_attr_size(payload);
1160 }
1161 
1162 /**
1163  * nla_type - attribute type
1164  * @nla: netlink attribute
1165  */
nla_type(const struct nlattr * nla)1166 static inline int nla_type(const struct nlattr *nla)
1167 {
1168 	return nla->nla_type & NLA_TYPE_MASK;
1169 }
1170 
1171 /**
1172  * nla_data - head of payload
1173  * @nla: netlink attribute
1174  */
nla_data(const struct nlattr * nla)1175 static inline void *nla_data(const struct nlattr *nla)
1176 {
1177 	return (char *) nla + NLA_HDRLEN;
1178 }
1179 
1180 /**
1181  * nla_len - length of payload
1182  * @nla: netlink attribute
1183  */
nla_len(const struct nlattr * nla)1184 static inline int nla_len(const struct nlattr *nla)
1185 {
1186 	return nla->nla_len - NLA_HDRLEN;
1187 }
1188 
1189 /**
1190  * nla_ok - check if the netlink attribute fits into the remaining bytes
1191  * @nla: netlink attribute
1192  * @remaining: number of bytes remaining in attribute stream
1193  */
nla_ok(const struct nlattr * nla,int remaining)1194 static inline int nla_ok(const struct nlattr *nla, int remaining)
1195 {
1196 	return remaining >= (int) sizeof(*nla) &&
1197 	       nla->nla_len >= sizeof(*nla) &&
1198 	       nla->nla_len <= remaining;
1199 }
1200 
1201 /**
1202  * nla_next - next netlink attribute in attribute stream
1203  * @nla: netlink attribute
1204  * @remaining: number of bytes remaining in attribute stream
1205  *
1206  * Returns the next netlink attribute in the attribute stream and
1207  * decrements remaining by the size of the current attribute.
1208  */
nla_next(const struct nlattr * nla,int * remaining)1209 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1210 {
1211 	unsigned int totlen = NLA_ALIGN(nla->nla_len);
1212 
1213 	*remaining -= totlen;
1214 	return (struct nlattr *) ((char *) nla + totlen);
1215 }
1216 
1217 /**
1218  * nla_find_nested - find attribute in a set of nested attributes
1219  * @nla: attribute containing the nested attributes
1220  * @attrtype: type of attribute to look for
1221  *
1222  * Returns the first attribute which matches the specified type.
1223  */
1224 static inline struct nlattr *
nla_find_nested(const struct nlattr * nla,int attrtype)1225 nla_find_nested(const struct nlattr *nla, int attrtype)
1226 {
1227 	return nla_find(nla_data(nla), nla_len(nla), attrtype);
1228 }
1229 
1230 /**
1231  * nla_parse_nested - parse nested attributes
1232  * @tb: destination array with maxtype+1 elements
1233  * @maxtype: maximum attribute type to be expected
1234  * @nla: attribute containing the nested attributes
1235  * @policy: validation policy
1236  * @extack: extended ACK report struct
1237  *
1238  * See nla_parse()
1239  */
nla_parse_nested(struct nlattr * tb[],int maxtype,const struct nlattr * nla,const struct nla_policy * policy,struct netlink_ext_ack * extack)1240 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1241 				   const struct nlattr *nla,
1242 				   const struct nla_policy *policy,
1243 				   struct netlink_ext_ack *extack)
1244 {
1245 	if (!(nla->nla_type & NLA_F_NESTED)) {
1246 		NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1247 		return -EINVAL;
1248 	}
1249 
1250 	return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1251 			   NL_VALIDATE_STRICT, extack);
1252 }
1253 
1254 /**
1255  * nla_parse_nested_deprecated - parse nested attributes
1256  * @tb: destination array with maxtype+1 elements
1257  * @maxtype: maximum attribute type to be expected
1258  * @nla: attribute containing the nested attributes
1259  * @policy: validation policy
1260  * @extack: extended ACK report struct
1261  *
1262  * See nla_parse_deprecated()
1263  */
nla_parse_nested_deprecated(struct nlattr * tb[],int maxtype,const struct nlattr * nla,const struct nla_policy * policy,struct netlink_ext_ack * extack)1264 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1265 					      const struct nlattr *nla,
1266 					      const struct nla_policy *policy,
1267 					      struct netlink_ext_ack *extack)
1268 {
1269 	return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1270 			   NL_VALIDATE_LIBERAL, extack);
1271 }
1272 
1273 /**
1274  * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1275  * @skb: socket buffer to add attribute to
1276  * @attrtype: attribute type
1277  * @value: numeric value
1278  */
nla_put_u8(struct sk_buff * skb,int attrtype,u8 value)1279 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1280 {
1281 	/* temporary variables to work around GCC PR81715 with asan-stack=1 */
1282 	u8 tmp = value;
1283 
1284 	return nla_put(skb, attrtype, sizeof(u8), &tmp);
1285 }
1286 
1287 /**
1288  * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1289  * @skb: socket buffer to add attribute to
1290  * @attrtype: attribute type
1291  * @value: numeric value
1292  */
nla_put_u16(struct sk_buff * skb,int attrtype,u16 value)1293 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1294 {
1295 	u16 tmp = value;
1296 
1297 	return nla_put(skb, attrtype, sizeof(u16), &tmp);
1298 }
1299 
1300 /**
1301  * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1302  * @skb: socket buffer to add attribute to
1303  * @attrtype: attribute type
1304  * @value: numeric value
1305  */
nla_put_be16(struct sk_buff * skb,int attrtype,__be16 value)1306 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1307 {
1308 	__be16 tmp = value;
1309 
1310 	return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1311 }
1312 
1313 /**
1314  * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1315  * @skb: socket buffer to add attribute to
1316  * @attrtype: attribute type
1317  * @value: numeric value
1318  */
nla_put_net16(struct sk_buff * skb,int attrtype,__be16 value)1319 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1320 {
1321 	__be16 tmp = value;
1322 
1323 	return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1324 }
1325 
1326 /**
1327  * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1328  * @skb: socket buffer to add attribute to
1329  * @attrtype: attribute type
1330  * @value: numeric value
1331  */
nla_put_le16(struct sk_buff * skb,int attrtype,__le16 value)1332 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1333 {
1334 	__le16 tmp = value;
1335 
1336 	return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1337 }
1338 
1339 /**
1340  * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1341  * @skb: socket buffer to add attribute to
1342  * @attrtype: attribute type
1343  * @value: numeric value
1344  */
nla_put_u32(struct sk_buff * skb,int attrtype,u32 value)1345 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1346 {
1347 	u32 tmp = value;
1348 
1349 	return nla_put(skb, attrtype, sizeof(u32), &tmp);
1350 }
1351 
1352 /**
1353  * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1354  * @skb: socket buffer to add attribute to
1355  * @attrtype: attribute type
1356  * @value: numeric value
1357  */
nla_put_be32(struct sk_buff * skb,int attrtype,__be32 value)1358 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1359 {
1360 	__be32 tmp = value;
1361 
1362 	return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1363 }
1364 
1365 /**
1366  * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1367  * @skb: socket buffer to add attribute to
1368  * @attrtype: attribute type
1369  * @value: numeric value
1370  */
nla_put_net32(struct sk_buff * skb,int attrtype,__be32 value)1371 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1372 {
1373 	__be32 tmp = value;
1374 
1375 	return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1376 }
1377 
1378 /**
1379  * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1380  * @skb: socket buffer to add attribute to
1381  * @attrtype: attribute type
1382  * @value: numeric value
1383  */
nla_put_le32(struct sk_buff * skb,int attrtype,__le32 value)1384 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1385 {
1386 	__le32 tmp = value;
1387 
1388 	return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1389 }
1390 
1391 /**
1392  * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1393  * @skb: socket buffer to add attribute to
1394  * @attrtype: attribute type
1395  * @value: numeric value
1396  * @padattr: attribute type for the padding
1397  */
nla_put_u64_64bit(struct sk_buff * skb,int attrtype,u64 value,int padattr)1398 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1399 				    u64 value, int padattr)
1400 {
1401 	u64 tmp = value;
1402 
1403 	return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1404 }
1405 
1406 /**
1407  * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1408  * @skb: socket buffer to add attribute to
1409  * @attrtype: attribute type
1410  * @value: numeric value
1411  * @padattr: attribute type for the padding
1412  */
nla_put_be64(struct sk_buff * skb,int attrtype,__be64 value,int padattr)1413 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1414 			       int padattr)
1415 {
1416 	__be64 tmp = value;
1417 
1418 	return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1419 }
1420 
1421 /**
1422  * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1423  * @skb: socket buffer to add attribute to
1424  * @attrtype: attribute type
1425  * @value: numeric value
1426  * @padattr: attribute type for the padding
1427  */
nla_put_net64(struct sk_buff * skb,int attrtype,__be64 value,int padattr)1428 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1429 				int padattr)
1430 {
1431 	__be64 tmp = value;
1432 
1433 	return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1434 			    padattr);
1435 }
1436 
1437 /**
1438  * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1439  * @skb: socket buffer to add attribute to
1440  * @attrtype: attribute type
1441  * @value: numeric value
1442  * @padattr: attribute type for the padding
1443  */
nla_put_le64(struct sk_buff * skb,int attrtype,__le64 value,int padattr)1444 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1445 			       int padattr)
1446 {
1447 	__le64 tmp = value;
1448 
1449 	return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1450 }
1451 
1452 /**
1453  * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1454  * @skb: socket buffer to add attribute to
1455  * @attrtype: attribute type
1456  * @value: numeric value
1457  */
nla_put_s8(struct sk_buff * skb,int attrtype,s8 value)1458 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1459 {
1460 	s8 tmp = value;
1461 
1462 	return nla_put(skb, attrtype, sizeof(s8), &tmp);
1463 }
1464 
1465 /**
1466  * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1467  * @skb: socket buffer to add attribute to
1468  * @attrtype: attribute type
1469  * @value: numeric value
1470  */
nla_put_s16(struct sk_buff * skb,int attrtype,s16 value)1471 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1472 {
1473 	s16 tmp = value;
1474 
1475 	return nla_put(skb, attrtype, sizeof(s16), &tmp);
1476 }
1477 
1478 /**
1479  * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1480  * @skb: socket buffer to add attribute to
1481  * @attrtype: attribute type
1482  * @value: numeric value
1483  */
nla_put_s32(struct sk_buff * skb,int attrtype,s32 value)1484 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1485 {
1486 	s32 tmp = value;
1487 
1488 	return nla_put(skb, attrtype, sizeof(s32), &tmp);
1489 }
1490 
1491 /**
1492  * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1493  * @skb: socket buffer to add attribute to
1494  * @attrtype: attribute type
1495  * @value: numeric value
1496  * @padattr: attribute type for the padding
1497  */
nla_put_s64(struct sk_buff * skb,int attrtype,s64 value,int padattr)1498 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1499 			      int padattr)
1500 {
1501 	s64 tmp = value;
1502 
1503 	return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1504 }
1505 
1506 /**
1507  * nla_put_string - Add a string netlink attribute to a socket buffer
1508  * @skb: socket buffer to add attribute to
1509  * @attrtype: attribute type
1510  * @str: NUL terminated string
1511  */
nla_put_string(struct sk_buff * skb,int attrtype,const char * str)1512 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1513 				 const char *str)
1514 {
1515 	return nla_put(skb, attrtype, strlen(str) + 1, str);
1516 }
1517 
1518 /**
1519  * nla_put_flag - Add a flag netlink attribute to a socket buffer
1520  * @skb: socket buffer to add attribute to
1521  * @attrtype: attribute type
1522  */
nla_put_flag(struct sk_buff * skb,int attrtype)1523 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1524 {
1525 	return nla_put(skb, attrtype, 0, NULL);
1526 }
1527 
1528 /**
1529  * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1530  * @skb: socket buffer to add attribute to
1531  * @attrtype: attribute type
1532  * @njiffies: number of jiffies to convert to msecs
1533  * @padattr: attribute type for the padding
1534  */
nla_put_msecs(struct sk_buff * skb,int attrtype,unsigned long njiffies,int padattr)1535 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1536 				unsigned long njiffies, int padattr)
1537 {
1538 	u64 tmp = jiffies_to_msecs(njiffies);
1539 
1540 	return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1541 }
1542 
1543 /**
1544  * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1545  * buffer
1546  * @skb: socket buffer to add attribute to
1547  * @attrtype: attribute type
1548  * @addr: IPv4 address
1549  */
nla_put_in_addr(struct sk_buff * skb,int attrtype,__be32 addr)1550 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1551 				  __be32 addr)
1552 {
1553 	__be32 tmp = addr;
1554 
1555 	return nla_put_be32(skb, attrtype, tmp);
1556 }
1557 
1558 /**
1559  * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1560  * buffer
1561  * @skb: socket buffer to add attribute to
1562  * @attrtype: attribute type
1563  * @addr: IPv6 address
1564  */
nla_put_in6_addr(struct sk_buff * skb,int attrtype,const struct in6_addr * addr)1565 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1566 				   const struct in6_addr *addr)
1567 {
1568 	return nla_put(skb, attrtype, sizeof(*addr), addr);
1569 }
1570 
1571 /**
1572  * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1573  * @skb: socket buffer to add attribute to
1574  * @attrtype: attribute type
1575  * @value: value carrying bits
1576  * @selector: selector of valid bits
1577  */
nla_put_bitfield32(struct sk_buff * skb,int attrtype,__u32 value,__u32 selector)1578 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1579 				     __u32 value, __u32 selector)
1580 {
1581 	struct nla_bitfield32 tmp = { value, selector, };
1582 
1583 	return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1584 }
1585 
1586 /**
1587  * nla_get_u32 - return payload of u32 attribute
1588  * @nla: u32 netlink attribute
1589  */
nla_get_u32(const struct nlattr * nla)1590 static inline u32 nla_get_u32(const struct nlattr *nla)
1591 {
1592 	return *(u32 *) nla_data(nla);
1593 }
1594 
1595 /**
1596  * nla_get_be32 - return payload of __be32 attribute
1597  * @nla: __be32 netlink attribute
1598  */
nla_get_be32(const struct nlattr * nla)1599 static inline __be32 nla_get_be32(const struct nlattr *nla)
1600 {
1601 	return *(__be32 *) nla_data(nla);
1602 }
1603 
1604 /**
1605  * nla_get_le32 - return payload of __le32 attribute
1606  * @nla: __le32 netlink attribute
1607  */
nla_get_le32(const struct nlattr * nla)1608 static inline __le32 nla_get_le32(const struct nlattr *nla)
1609 {
1610 	return *(__le32 *) nla_data(nla);
1611 }
1612 
1613 /**
1614  * nla_get_u16 - return payload of u16 attribute
1615  * @nla: u16 netlink attribute
1616  */
nla_get_u16(const struct nlattr * nla)1617 static inline u16 nla_get_u16(const struct nlattr *nla)
1618 {
1619 	return *(u16 *) nla_data(nla);
1620 }
1621 
1622 /**
1623  * nla_get_be16 - return payload of __be16 attribute
1624  * @nla: __be16 netlink attribute
1625  */
nla_get_be16(const struct nlattr * nla)1626 static inline __be16 nla_get_be16(const struct nlattr *nla)
1627 {
1628 	return *(__be16 *) nla_data(nla);
1629 }
1630 
1631 /**
1632  * nla_get_le16 - return payload of __le16 attribute
1633  * @nla: __le16 netlink attribute
1634  */
nla_get_le16(const struct nlattr * nla)1635 static inline __le16 nla_get_le16(const struct nlattr *nla)
1636 {
1637 	return *(__le16 *) nla_data(nla);
1638 }
1639 
1640 /**
1641  * nla_get_u8 - return payload of u8 attribute
1642  * @nla: u8 netlink attribute
1643  */
nla_get_u8(const struct nlattr * nla)1644 static inline u8 nla_get_u8(const struct nlattr *nla)
1645 {
1646 	return *(u8 *) nla_data(nla);
1647 }
1648 
1649 /**
1650  * nla_get_u64 - return payload of u64 attribute
1651  * @nla: u64 netlink attribute
1652  */
nla_get_u64(const struct nlattr * nla)1653 static inline u64 nla_get_u64(const struct nlattr *nla)
1654 {
1655 	u64 tmp;
1656 
1657 	nla_memcpy(&tmp, nla, sizeof(tmp));
1658 
1659 	return tmp;
1660 }
1661 
1662 /**
1663  * nla_get_be64 - return payload of __be64 attribute
1664  * @nla: __be64 netlink attribute
1665  */
nla_get_be64(const struct nlattr * nla)1666 static inline __be64 nla_get_be64(const struct nlattr *nla)
1667 {
1668 	__be64 tmp;
1669 
1670 	nla_memcpy(&tmp, nla, sizeof(tmp));
1671 
1672 	return tmp;
1673 }
1674 
1675 /**
1676  * nla_get_le64 - return payload of __le64 attribute
1677  * @nla: __le64 netlink attribute
1678  */
nla_get_le64(const struct nlattr * nla)1679 static inline __le64 nla_get_le64(const struct nlattr *nla)
1680 {
1681 	return *(__le64 *) nla_data(nla);
1682 }
1683 
1684 /**
1685  * nla_get_s32 - return payload of s32 attribute
1686  * @nla: s32 netlink attribute
1687  */
nla_get_s32(const struct nlattr * nla)1688 static inline s32 nla_get_s32(const struct nlattr *nla)
1689 {
1690 	return *(s32 *) nla_data(nla);
1691 }
1692 
1693 /**
1694  * nla_get_s16 - return payload of s16 attribute
1695  * @nla: s16 netlink attribute
1696  */
nla_get_s16(const struct nlattr * nla)1697 static inline s16 nla_get_s16(const struct nlattr *nla)
1698 {
1699 	return *(s16 *) nla_data(nla);
1700 }
1701 
1702 /**
1703  * nla_get_s8 - return payload of s8 attribute
1704  * @nla: s8 netlink attribute
1705  */
nla_get_s8(const struct nlattr * nla)1706 static inline s8 nla_get_s8(const struct nlattr *nla)
1707 {
1708 	return *(s8 *) nla_data(nla);
1709 }
1710 
1711 /**
1712  * nla_get_s64 - return payload of s64 attribute
1713  * @nla: s64 netlink attribute
1714  */
nla_get_s64(const struct nlattr * nla)1715 static inline s64 nla_get_s64(const struct nlattr *nla)
1716 {
1717 	s64 tmp;
1718 
1719 	nla_memcpy(&tmp, nla, sizeof(tmp));
1720 
1721 	return tmp;
1722 }
1723 
1724 /**
1725  * nla_get_flag - return payload of flag attribute
1726  * @nla: flag netlink attribute
1727  */
nla_get_flag(const struct nlattr * nla)1728 static inline int nla_get_flag(const struct nlattr *nla)
1729 {
1730 	return !!nla;
1731 }
1732 
1733 /**
1734  * nla_get_msecs - return payload of msecs attribute
1735  * @nla: msecs netlink attribute
1736  *
1737  * Returns the number of milliseconds in jiffies.
1738  */
nla_get_msecs(const struct nlattr * nla)1739 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1740 {
1741 	u64 msecs = nla_get_u64(nla);
1742 
1743 	return msecs_to_jiffies((unsigned long) msecs);
1744 }
1745 
1746 /**
1747  * nla_get_in_addr - return payload of IPv4 address attribute
1748  * @nla: IPv4 address netlink attribute
1749  */
nla_get_in_addr(const struct nlattr * nla)1750 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1751 {
1752 	return *(__be32 *) nla_data(nla);
1753 }
1754 
1755 /**
1756  * nla_get_in6_addr - return payload of IPv6 address attribute
1757  * @nla: IPv6 address netlink attribute
1758  */
nla_get_in6_addr(const struct nlattr * nla)1759 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1760 {
1761 	struct in6_addr tmp;
1762 
1763 	nla_memcpy(&tmp, nla, sizeof(tmp));
1764 	return tmp;
1765 }
1766 
1767 /**
1768  * nla_get_bitfield32 - return payload of 32 bitfield attribute
1769  * @nla: nla_bitfield32 attribute
1770  */
nla_get_bitfield32(const struct nlattr * nla)1771 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1772 {
1773 	struct nla_bitfield32 tmp;
1774 
1775 	nla_memcpy(&tmp, nla, sizeof(tmp));
1776 	return tmp;
1777 }
1778 
1779 /**
1780  * nla_memdup - duplicate attribute memory (kmemdup)
1781  * @src: netlink attribute to duplicate from
1782  * @gfp: GFP mask
1783  */
nla_memdup(const struct nlattr * src,gfp_t gfp)1784 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1785 {
1786 	return kmemdup(nla_data(src), nla_len(src), gfp);
1787 }
1788 
1789 /**
1790  * nla_nest_start_noflag - Start a new level of nested attributes
1791  * @skb: socket buffer to add attributes to
1792  * @attrtype: attribute type of container
1793  *
1794  * This function exists for backward compatibility to use in APIs which never
1795  * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1796  * nla_nest_start() which sets the flag.
1797  *
1798  * Returns the container attribute or NULL on error
1799  */
nla_nest_start_noflag(struct sk_buff * skb,int attrtype)1800 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1801 						   int attrtype)
1802 {
1803 	struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1804 
1805 	if (nla_put(skb, attrtype, 0, NULL) < 0)
1806 		return NULL;
1807 
1808 	return start;
1809 }
1810 
1811 /**
1812  * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1813  * @skb: socket buffer to add attributes to
1814  * @attrtype: attribute type of container
1815  *
1816  * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1817  * flag. This is the preferred function to use in new code.
1818  *
1819  * Returns the container attribute or NULL on error
1820  */
nla_nest_start(struct sk_buff * skb,int attrtype)1821 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1822 {
1823 	return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1824 }
1825 
1826 /**
1827  * nla_nest_end - Finalize nesting of attributes
1828  * @skb: socket buffer the attributes are stored in
1829  * @start: container attribute
1830  *
1831  * Corrects the container attribute header to include the all
1832  * appeneded attributes.
1833  *
1834  * Returns the total data length of the skb.
1835  */
nla_nest_end(struct sk_buff * skb,struct nlattr * start)1836 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1837 {
1838 	start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1839 	return skb->len;
1840 }
1841 
1842 /**
1843  * nla_nest_cancel - Cancel nesting of attributes
1844  * @skb: socket buffer the message is stored in
1845  * @start: container attribute
1846  *
1847  * Removes the container attribute and including all nested
1848  * attributes. Returns -EMSGSIZE
1849  */
nla_nest_cancel(struct sk_buff * skb,struct nlattr * start)1850 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1851 {
1852 	nlmsg_trim(skb, start);
1853 }
1854 
1855 /**
1856  * __nla_validate_nested - Validate a stream of nested attributes
1857  * @start: container attribute
1858  * @maxtype: maximum attribute type to be expected
1859  * @policy: validation policy
1860  * @validate: validation strictness
1861  * @extack: extended ACK report struct
1862  *
1863  * Validates all attributes in the nested attribute stream against the
1864  * specified policy. Attributes with a type exceeding maxtype will be
1865  * ignored. See documenation of struct nla_policy for more details.
1866  *
1867  * Returns 0 on success or a negative error code.
1868  */
__nla_validate_nested(const struct nlattr * start,int maxtype,const struct nla_policy * policy,unsigned int validate,struct netlink_ext_ack * extack)1869 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1870 					const struct nla_policy *policy,
1871 					unsigned int validate,
1872 					struct netlink_ext_ack *extack)
1873 {
1874 	return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1875 			      validate, extack);
1876 }
1877 
1878 static inline int
nla_validate_nested(const struct nlattr * start,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)1879 nla_validate_nested(const struct nlattr *start, int maxtype,
1880 		    const struct nla_policy *policy,
1881 		    struct netlink_ext_ack *extack)
1882 {
1883 	return __nla_validate_nested(start, maxtype, policy,
1884 				     NL_VALIDATE_STRICT, extack);
1885 }
1886 
1887 static inline int
nla_validate_nested_deprecated(const struct nlattr * start,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)1888 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1889 			       const struct nla_policy *policy,
1890 			       struct netlink_ext_ack *extack)
1891 {
1892 	return __nla_validate_nested(start, maxtype, policy,
1893 				     NL_VALIDATE_LIBERAL, extack);
1894 }
1895 
1896 /**
1897  * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1898  * @skb: socket buffer the message is stored in
1899  *
1900  * Return true if padding is needed to align the next attribute (nla_data()) to
1901  * a 64-bit aligned area.
1902  */
nla_need_padding_for_64bit(struct sk_buff * skb)1903 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1904 {
1905 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1906 	/* The nlattr header is 4 bytes in size, that's why we test
1907 	 * if the skb->data _is_ aligned.  A NOP attribute, plus
1908 	 * nlattr header for next attribute, will make nla_data()
1909 	 * 8-byte aligned.
1910 	 */
1911 	if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1912 		return true;
1913 #endif
1914 	return false;
1915 }
1916 
1917 /**
1918  * nla_align_64bit - 64-bit align the nla_data() of next attribute
1919  * @skb: socket buffer the message is stored in
1920  * @padattr: attribute type for the padding
1921  *
1922  * Conditionally emit a padding netlink attribute in order to make
1923  * the next attribute we emit have a 64-bit aligned nla_data() area.
1924  * This will only be done in architectures which do not have
1925  * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1926  *
1927  * Returns zero on success or a negative error code.
1928  */
nla_align_64bit(struct sk_buff * skb,int padattr)1929 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1930 {
1931 	if (nla_need_padding_for_64bit(skb) &&
1932 	    !nla_reserve(skb, padattr, 0))
1933 		return -EMSGSIZE;
1934 
1935 	return 0;
1936 }
1937 
1938 /**
1939  * nla_total_size_64bit - total length of attribute including padding
1940  * @payload: length of payload
1941  */
nla_total_size_64bit(int payload)1942 static inline int nla_total_size_64bit(int payload)
1943 {
1944 	return NLA_ALIGN(nla_attr_size(payload))
1945 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1946 		+ NLA_ALIGN(nla_attr_size(0))
1947 #endif
1948 		;
1949 }
1950 
1951 /**
1952  * nla_for_each_attr - iterate over a stream of attributes
1953  * @pos: loop counter, set to current attribute
1954  * @head: head of attribute stream
1955  * @len: length of attribute stream
1956  * @rem: initialized to len, holds bytes currently remaining in stream
1957  */
1958 #define nla_for_each_attr(pos, head, len, rem) \
1959 	for (pos = head, rem = len; \
1960 	     nla_ok(pos, rem); \
1961 	     pos = nla_next(pos, &(rem)))
1962 
1963 /**
1964  * nla_for_each_nested - iterate over nested attributes
1965  * @pos: loop counter, set to current attribute
1966  * @nla: attribute containing the nested attributes
1967  * @rem: initialized to len, holds bytes currently remaining in stream
1968  */
1969 #define nla_for_each_nested(pos, nla, rem) \
1970 	nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1971 
1972 /**
1973  * nla_is_last - Test if attribute is last in stream
1974  * @nla: attribute to test
1975  * @rem: bytes remaining in stream
1976  */
nla_is_last(const struct nlattr * nla,int rem)1977 static inline bool nla_is_last(const struct nlattr *nla, int rem)
1978 {
1979 	return nla->nla_len == rem;
1980 }
1981 
1982 void nla_get_range_unsigned(const struct nla_policy *pt,
1983 			    struct netlink_range_validation *range);
1984 void nla_get_range_signed(const struct nla_policy *pt,
1985 			  struct netlink_range_validation_signed *range);
1986 
1987 struct netlink_policy_dump_state;
1988 
1989 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
1990 				   const struct nla_policy *policy,
1991 				   unsigned int maxtype);
1992 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
1993 				       const struct nla_policy *policy,
1994 				       unsigned int maxtype);
1995 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
1996 int netlink_policy_dump_write(struct sk_buff *skb,
1997 			      struct netlink_policy_dump_state *state);
1998 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
1999 int netlink_policy_dump_write_attr(struct sk_buff *skb,
2000 				   const struct nla_policy *pt,
2001 				   int nestattr);
2002 void netlink_policy_dump_free(struct netlink_policy_dump_state *state);
2003 
2004 #endif
2005