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_put_answer - Add a new callback based netlink message to an skb
942  * @skb: socket buffer to store message in
943  * @cb: netlink callback
944  * @type: message type
945  * @payload: length of message payload
946  * @flags: message flags
947  *
948  * Returns NULL if the tailroom of the skb is insufficient to store
949  * the message header and payload.
950  */
nlmsg_put_answer(struct sk_buff * skb,struct netlink_callback * cb,int type,int payload,int flags)951 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
952 						struct netlink_callback *cb,
953 						int type, int payload,
954 						int flags)
955 {
956 	return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
957 			 type, payload, flags);
958 }
959 
960 /**
961  * nlmsg_new - Allocate a new netlink message
962  * @payload: size of the message payload
963  * @flags: the type of memory to allocate.
964  *
965  * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
966  * and a good default is needed.
967  */
nlmsg_new(size_t payload,gfp_t flags)968 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
969 {
970 	return alloc_skb(nlmsg_total_size(payload), flags);
971 }
972 
973 /**
974  * nlmsg_end - Finalize a netlink message
975  * @skb: socket buffer the message is stored in
976  * @nlh: netlink message header
977  *
978  * Corrects the netlink message header to include the appeneded
979  * attributes. Only necessary if attributes have been added to
980  * the message.
981  */
nlmsg_end(struct sk_buff * skb,struct nlmsghdr * nlh)982 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
983 {
984 	nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
985 }
986 
987 /**
988  * nlmsg_get_pos - return current position in netlink message
989  * @skb: socket buffer the message is stored in
990  *
991  * Returns a pointer to the current tail of the message.
992  */
nlmsg_get_pos(struct sk_buff * skb)993 static inline void *nlmsg_get_pos(struct sk_buff *skb)
994 {
995 	return skb_tail_pointer(skb);
996 }
997 
998 /**
999  * nlmsg_trim - Trim message to a mark
1000  * @skb: socket buffer the message is stored in
1001  * @mark: mark to trim to
1002  *
1003  * Trims the message to the provided mark.
1004  */
nlmsg_trim(struct sk_buff * skb,const void * mark)1005 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1006 {
1007 	if (mark) {
1008 		WARN_ON((unsigned char *) mark < skb->data);
1009 		skb_trim(skb, (unsigned char *) mark - skb->data);
1010 	}
1011 }
1012 
1013 /**
1014  * nlmsg_cancel - Cancel construction of a netlink message
1015  * @skb: socket buffer the message is stored in
1016  * @nlh: netlink message header
1017  *
1018  * Removes the complete netlink message including all
1019  * attributes from the socket buffer again.
1020  */
nlmsg_cancel(struct sk_buff * skb,struct nlmsghdr * nlh)1021 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1022 {
1023 	nlmsg_trim(skb, nlh);
1024 }
1025 
1026 /**
1027  * nlmsg_free - free a netlink message
1028  * @skb: socket buffer of netlink message
1029  */
nlmsg_free(struct sk_buff * skb)1030 static inline void nlmsg_free(struct sk_buff *skb)
1031 {
1032 	kfree_skb(skb);
1033 }
1034 
1035 /**
1036  * nlmsg_multicast - multicast a netlink message
1037  * @sk: netlink socket to spread messages to
1038  * @skb: netlink message as socket buffer
1039  * @portid: own netlink portid to avoid sending to yourself
1040  * @group: multicast group id
1041  * @flags: allocation flags
1042  */
nlmsg_multicast(struct sock * sk,struct sk_buff * skb,u32 portid,unsigned int group,gfp_t flags)1043 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1044 				  u32 portid, unsigned int group, gfp_t flags)
1045 {
1046 	int err;
1047 
1048 	NETLINK_CB(skb).dst_group = group;
1049 
1050 	err = netlink_broadcast(sk, skb, portid, group, flags);
1051 	if (err > 0)
1052 		err = 0;
1053 
1054 	return err;
1055 }
1056 
1057 /**
1058  * nlmsg_unicast - unicast a netlink message
1059  * @sk: netlink socket to spread message to
1060  * @skb: netlink message as socket buffer
1061  * @portid: netlink portid of the destination socket
1062  */
nlmsg_unicast(struct sock * sk,struct sk_buff * skb,u32 portid)1063 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1064 {
1065 	int err;
1066 
1067 	err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1068 	if (err > 0)
1069 		err = 0;
1070 
1071 	return err;
1072 }
1073 
1074 /**
1075  * nlmsg_for_each_msg - iterate over a stream of messages
1076  * @pos: loop counter, set to current message
1077  * @head: head of message stream
1078  * @len: length of message stream
1079  * @rem: initialized to len, holds bytes currently remaining in stream
1080  */
1081 #define nlmsg_for_each_msg(pos, head, len, rem) \
1082 	for (pos = head, rem = len; \
1083 	     nlmsg_ok(pos, rem); \
1084 	     pos = nlmsg_next(pos, &(rem)))
1085 
1086 /**
1087  * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1088  * @cb: netlink callback structure that stores the sequence number
1089  * @nlh: netlink message header to write the flag to
1090  *
1091  * This function checks if the sequence (generation) number changed during dump
1092  * and if it did, advertises it in the netlink message header.
1093  *
1094  * The correct way to use it is to set cb->seq to the generation counter when
1095  * all locks for dumping have been acquired, and then call this function for
1096  * each message that is generated.
1097  *
1098  * Note that due to initialisation concerns, 0 is an invalid sequence number
1099  * and must not be used by code that uses this functionality.
1100  */
1101 static inline void
nl_dump_check_consistent(struct netlink_callback * cb,struct nlmsghdr * nlh)1102 nl_dump_check_consistent(struct netlink_callback *cb,
1103 			 struct nlmsghdr *nlh)
1104 {
1105 	if (cb->prev_seq && cb->seq != cb->prev_seq)
1106 		nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1107 	cb->prev_seq = cb->seq;
1108 }
1109 
1110 /**************************************************************************
1111  * Netlink Attributes
1112  **************************************************************************/
1113 
1114 /**
1115  * nla_attr_size - length of attribute not including padding
1116  * @payload: length of payload
1117  */
nla_attr_size(int payload)1118 static inline int nla_attr_size(int payload)
1119 {
1120 	return NLA_HDRLEN + payload;
1121 }
1122 
1123 /**
1124  * nla_total_size - total length of attribute including padding
1125  * @payload: length of payload
1126  */
nla_total_size(int payload)1127 static inline int nla_total_size(int payload)
1128 {
1129 	return NLA_ALIGN(nla_attr_size(payload));
1130 }
1131 
1132 /**
1133  * nla_padlen - length of padding at the tail of attribute
1134  * @payload: length of payload
1135  */
nla_padlen(int payload)1136 static inline int nla_padlen(int payload)
1137 {
1138 	return nla_total_size(payload) - nla_attr_size(payload);
1139 }
1140 
1141 /**
1142  * nla_type - attribute type
1143  * @nla: netlink attribute
1144  */
nla_type(const struct nlattr * nla)1145 static inline int nla_type(const struct nlattr *nla)
1146 {
1147 	return nla->nla_type & NLA_TYPE_MASK;
1148 }
1149 
1150 /**
1151  * nla_data - head of payload
1152  * @nla: netlink attribute
1153  */
nla_data(const struct nlattr * nla)1154 static inline void *nla_data(const struct nlattr *nla)
1155 {
1156 	return (char *) nla + NLA_HDRLEN;
1157 }
1158 
1159 /**
1160  * nla_len - length of payload
1161  * @nla: netlink attribute
1162  */
nla_len(const struct nlattr * nla)1163 static inline int nla_len(const struct nlattr *nla)
1164 {
1165 	return nla->nla_len - NLA_HDRLEN;
1166 }
1167 
1168 /**
1169  * nla_ok - check if the netlink attribute fits into the remaining bytes
1170  * @nla: netlink attribute
1171  * @remaining: number of bytes remaining in attribute stream
1172  */
nla_ok(const struct nlattr * nla,int remaining)1173 static inline int nla_ok(const struct nlattr *nla, int remaining)
1174 {
1175 	return remaining >= (int) sizeof(*nla) &&
1176 	       nla->nla_len >= sizeof(*nla) &&
1177 	       nla->nla_len <= remaining;
1178 }
1179 
1180 /**
1181  * nla_next - next netlink attribute in attribute stream
1182  * @nla: netlink attribute
1183  * @remaining: number of bytes remaining in attribute stream
1184  *
1185  * Returns the next netlink attribute in the attribute stream and
1186  * decrements remaining by the size of the current attribute.
1187  */
nla_next(const struct nlattr * nla,int * remaining)1188 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1189 {
1190 	unsigned int totlen = NLA_ALIGN(nla->nla_len);
1191 
1192 	*remaining -= totlen;
1193 	return (struct nlattr *) ((char *) nla + totlen);
1194 }
1195 
1196 /**
1197  * nla_find_nested - find attribute in a set of nested attributes
1198  * @nla: attribute containing the nested attributes
1199  * @attrtype: type of attribute to look for
1200  *
1201  * Returns the first attribute which matches the specified type.
1202  */
1203 static inline struct nlattr *
nla_find_nested(const struct nlattr * nla,int attrtype)1204 nla_find_nested(const struct nlattr *nla, int attrtype)
1205 {
1206 	return nla_find(nla_data(nla), nla_len(nla), attrtype);
1207 }
1208 
1209 /**
1210  * nla_parse_nested - parse nested attributes
1211  * @tb: destination array with maxtype+1 elements
1212  * @maxtype: maximum attribute type to be expected
1213  * @nla: attribute containing the nested attributes
1214  * @policy: validation policy
1215  * @extack: extended ACK report struct
1216  *
1217  * See nla_parse()
1218  */
nla_parse_nested(struct nlattr * tb[],int maxtype,const struct nlattr * nla,const struct nla_policy * policy,struct netlink_ext_ack * extack)1219 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1220 				   const struct nlattr *nla,
1221 				   const struct nla_policy *policy,
1222 				   struct netlink_ext_ack *extack)
1223 {
1224 	if (!(nla->nla_type & NLA_F_NESTED)) {
1225 		NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1226 		return -EINVAL;
1227 	}
1228 
1229 	return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1230 			   NL_VALIDATE_STRICT, extack);
1231 }
1232 
1233 /**
1234  * nla_parse_nested_deprecated - parse nested attributes
1235  * @tb: destination array with maxtype+1 elements
1236  * @maxtype: maximum attribute type to be expected
1237  * @nla: attribute containing the nested attributes
1238  * @policy: validation policy
1239  * @extack: extended ACK report struct
1240  *
1241  * See nla_parse_deprecated()
1242  */
nla_parse_nested_deprecated(struct nlattr * tb[],int maxtype,const struct nlattr * nla,const struct nla_policy * policy,struct netlink_ext_ack * extack)1243 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1244 					      const struct nlattr *nla,
1245 					      const struct nla_policy *policy,
1246 					      struct netlink_ext_ack *extack)
1247 {
1248 	return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1249 			   NL_VALIDATE_LIBERAL, extack);
1250 }
1251 
1252 /**
1253  * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1254  * @skb: socket buffer to add attribute to
1255  * @attrtype: attribute type
1256  * @value: numeric value
1257  */
nla_put_u8(struct sk_buff * skb,int attrtype,u8 value)1258 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1259 {
1260 	/* temporary variables to work around GCC PR81715 with asan-stack=1 */
1261 	u8 tmp = value;
1262 
1263 	return nla_put(skb, attrtype, sizeof(u8), &tmp);
1264 }
1265 
1266 /**
1267  * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1268  * @skb: socket buffer to add attribute to
1269  * @attrtype: attribute type
1270  * @value: numeric value
1271  */
nla_put_u16(struct sk_buff * skb,int attrtype,u16 value)1272 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1273 {
1274 	u16 tmp = value;
1275 
1276 	return nla_put(skb, attrtype, sizeof(u16), &tmp);
1277 }
1278 
1279 /**
1280  * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1281  * @skb: socket buffer to add attribute to
1282  * @attrtype: attribute type
1283  * @value: numeric value
1284  */
nla_put_be16(struct sk_buff * skb,int attrtype,__be16 value)1285 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1286 {
1287 	__be16 tmp = value;
1288 
1289 	return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1290 }
1291 
1292 /**
1293  * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1294  * @skb: socket buffer to add attribute to
1295  * @attrtype: attribute type
1296  * @value: numeric value
1297  */
nla_put_net16(struct sk_buff * skb,int attrtype,__be16 value)1298 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1299 {
1300 	__be16 tmp = value;
1301 
1302 	return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1303 }
1304 
1305 /**
1306  * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1307  * @skb: socket buffer to add attribute to
1308  * @attrtype: attribute type
1309  * @value: numeric value
1310  */
nla_put_le16(struct sk_buff * skb,int attrtype,__le16 value)1311 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1312 {
1313 	__le16 tmp = value;
1314 
1315 	return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1316 }
1317 
1318 /**
1319  * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1320  * @skb: socket buffer to add attribute to
1321  * @attrtype: attribute type
1322  * @value: numeric value
1323  */
nla_put_u32(struct sk_buff * skb,int attrtype,u32 value)1324 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1325 {
1326 	u32 tmp = value;
1327 
1328 	return nla_put(skb, attrtype, sizeof(u32), &tmp);
1329 }
1330 
1331 /**
1332  * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1333  * @skb: socket buffer to add attribute to
1334  * @attrtype: attribute type
1335  * @value: numeric value
1336  */
nla_put_be32(struct sk_buff * skb,int attrtype,__be32 value)1337 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1338 {
1339 	__be32 tmp = value;
1340 
1341 	return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1342 }
1343 
1344 /**
1345  * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1346  * @skb: socket buffer to add attribute to
1347  * @attrtype: attribute type
1348  * @value: numeric value
1349  */
nla_put_net32(struct sk_buff * skb,int attrtype,__be32 value)1350 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1351 {
1352 	__be32 tmp = value;
1353 
1354 	return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1355 }
1356 
1357 /**
1358  * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1359  * @skb: socket buffer to add attribute to
1360  * @attrtype: attribute type
1361  * @value: numeric value
1362  */
nla_put_le32(struct sk_buff * skb,int attrtype,__le32 value)1363 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1364 {
1365 	__le32 tmp = value;
1366 
1367 	return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1368 }
1369 
1370 /**
1371  * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1372  * @skb: socket buffer to add attribute to
1373  * @attrtype: attribute type
1374  * @value: numeric value
1375  * @padattr: attribute type for the padding
1376  */
nla_put_u64_64bit(struct sk_buff * skb,int attrtype,u64 value,int padattr)1377 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1378 				    u64 value, int padattr)
1379 {
1380 	u64 tmp = value;
1381 
1382 	return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1383 }
1384 
1385 /**
1386  * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1387  * @skb: socket buffer to add attribute to
1388  * @attrtype: attribute type
1389  * @value: numeric value
1390  * @padattr: attribute type for the padding
1391  */
nla_put_be64(struct sk_buff * skb,int attrtype,__be64 value,int padattr)1392 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1393 			       int padattr)
1394 {
1395 	__be64 tmp = value;
1396 
1397 	return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1398 }
1399 
1400 /**
1401  * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1402  * @skb: socket buffer to add attribute to
1403  * @attrtype: attribute type
1404  * @value: numeric value
1405  * @padattr: attribute type for the padding
1406  */
nla_put_net64(struct sk_buff * skb,int attrtype,__be64 value,int padattr)1407 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1408 				int padattr)
1409 {
1410 	__be64 tmp = value;
1411 
1412 	return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1413 			    padattr);
1414 }
1415 
1416 /**
1417  * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1418  * @skb: socket buffer to add attribute to
1419  * @attrtype: attribute type
1420  * @value: numeric value
1421  * @padattr: attribute type for the padding
1422  */
nla_put_le64(struct sk_buff * skb,int attrtype,__le64 value,int padattr)1423 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1424 			       int padattr)
1425 {
1426 	__le64 tmp = value;
1427 
1428 	return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1429 }
1430 
1431 /**
1432  * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1433  * @skb: socket buffer to add attribute to
1434  * @attrtype: attribute type
1435  * @value: numeric value
1436  */
nla_put_s8(struct sk_buff * skb,int attrtype,s8 value)1437 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1438 {
1439 	s8 tmp = value;
1440 
1441 	return nla_put(skb, attrtype, sizeof(s8), &tmp);
1442 }
1443 
1444 /**
1445  * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1446  * @skb: socket buffer to add attribute to
1447  * @attrtype: attribute type
1448  * @value: numeric value
1449  */
nla_put_s16(struct sk_buff * skb,int attrtype,s16 value)1450 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1451 {
1452 	s16 tmp = value;
1453 
1454 	return nla_put(skb, attrtype, sizeof(s16), &tmp);
1455 }
1456 
1457 /**
1458  * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1459  * @skb: socket buffer to add attribute to
1460  * @attrtype: attribute type
1461  * @value: numeric value
1462  */
nla_put_s32(struct sk_buff * skb,int attrtype,s32 value)1463 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1464 {
1465 	s32 tmp = value;
1466 
1467 	return nla_put(skb, attrtype, sizeof(s32), &tmp);
1468 }
1469 
1470 /**
1471  * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1472  * @skb: socket buffer to add attribute to
1473  * @attrtype: attribute type
1474  * @value: numeric value
1475  * @padattr: attribute type for the padding
1476  */
nla_put_s64(struct sk_buff * skb,int attrtype,s64 value,int padattr)1477 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1478 			      int padattr)
1479 {
1480 	s64 tmp = value;
1481 
1482 	return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1483 }
1484 
1485 /**
1486  * nla_put_string - Add a string netlink attribute to a socket buffer
1487  * @skb: socket buffer to add attribute to
1488  * @attrtype: attribute type
1489  * @str: NUL terminated string
1490  */
nla_put_string(struct sk_buff * skb,int attrtype,const char * str)1491 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1492 				 const char *str)
1493 {
1494 	return nla_put(skb, attrtype, strlen(str) + 1, str);
1495 }
1496 
1497 /**
1498  * nla_put_flag - Add a flag netlink attribute to a socket buffer
1499  * @skb: socket buffer to add attribute to
1500  * @attrtype: attribute type
1501  */
nla_put_flag(struct sk_buff * skb,int attrtype)1502 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1503 {
1504 	return nla_put(skb, attrtype, 0, NULL);
1505 }
1506 
1507 /**
1508  * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1509  * @skb: socket buffer to add attribute to
1510  * @attrtype: attribute type
1511  * @njiffies: number of jiffies to convert to msecs
1512  * @padattr: attribute type for the padding
1513  */
nla_put_msecs(struct sk_buff * skb,int attrtype,unsigned long njiffies,int padattr)1514 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1515 				unsigned long njiffies, int padattr)
1516 {
1517 	u64 tmp = jiffies_to_msecs(njiffies);
1518 
1519 	return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1520 }
1521 
1522 /**
1523  * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1524  * buffer
1525  * @skb: socket buffer to add attribute to
1526  * @attrtype: attribute type
1527  * @addr: IPv4 address
1528  */
nla_put_in_addr(struct sk_buff * skb,int attrtype,__be32 addr)1529 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1530 				  __be32 addr)
1531 {
1532 	__be32 tmp = addr;
1533 
1534 	return nla_put_be32(skb, attrtype, tmp);
1535 }
1536 
1537 /**
1538  * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1539  * buffer
1540  * @skb: socket buffer to add attribute to
1541  * @attrtype: attribute type
1542  * @addr: IPv6 address
1543  */
nla_put_in6_addr(struct sk_buff * skb,int attrtype,const struct in6_addr * addr)1544 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1545 				   const struct in6_addr *addr)
1546 {
1547 	return nla_put(skb, attrtype, sizeof(*addr), addr);
1548 }
1549 
1550 /**
1551  * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1552  * @skb: socket buffer to add attribute to
1553  * @attrtype: attribute type
1554  * @value: value carrying bits
1555  * @selector: selector of valid bits
1556  */
nla_put_bitfield32(struct sk_buff * skb,int attrtype,__u32 value,__u32 selector)1557 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1558 				     __u32 value, __u32 selector)
1559 {
1560 	struct nla_bitfield32 tmp = { value, selector, };
1561 
1562 	return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1563 }
1564 
1565 /**
1566  * nla_get_u32 - return payload of u32 attribute
1567  * @nla: u32 netlink attribute
1568  */
nla_get_u32(const struct nlattr * nla)1569 static inline u32 nla_get_u32(const struct nlattr *nla)
1570 {
1571 	return *(u32 *) nla_data(nla);
1572 }
1573 
1574 /**
1575  * nla_get_be32 - return payload of __be32 attribute
1576  * @nla: __be32 netlink attribute
1577  */
nla_get_be32(const struct nlattr * nla)1578 static inline __be32 nla_get_be32(const struct nlattr *nla)
1579 {
1580 	return *(__be32 *) nla_data(nla);
1581 }
1582 
1583 /**
1584  * nla_get_le32 - return payload of __le32 attribute
1585  * @nla: __le32 netlink attribute
1586  */
nla_get_le32(const struct nlattr * nla)1587 static inline __le32 nla_get_le32(const struct nlattr *nla)
1588 {
1589 	return *(__le32 *) nla_data(nla);
1590 }
1591 
1592 /**
1593  * nla_get_u16 - return payload of u16 attribute
1594  * @nla: u16 netlink attribute
1595  */
nla_get_u16(const struct nlattr * nla)1596 static inline u16 nla_get_u16(const struct nlattr *nla)
1597 {
1598 	return *(u16 *) nla_data(nla);
1599 }
1600 
1601 /**
1602  * nla_get_be16 - return payload of __be16 attribute
1603  * @nla: __be16 netlink attribute
1604  */
nla_get_be16(const struct nlattr * nla)1605 static inline __be16 nla_get_be16(const struct nlattr *nla)
1606 {
1607 	return *(__be16 *) nla_data(nla);
1608 }
1609 
1610 /**
1611  * nla_get_le16 - return payload of __le16 attribute
1612  * @nla: __le16 netlink attribute
1613  */
nla_get_le16(const struct nlattr * nla)1614 static inline __le16 nla_get_le16(const struct nlattr *nla)
1615 {
1616 	return *(__le16 *) nla_data(nla);
1617 }
1618 
1619 /**
1620  * nla_get_u8 - return payload of u8 attribute
1621  * @nla: u8 netlink attribute
1622  */
nla_get_u8(const struct nlattr * nla)1623 static inline u8 nla_get_u8(const struct nlattr *nla)
1624 {
1625 	return *(u8 *) nla_data(nla);
1626 }
1627 
1628 /**
1629  * nla_get_u64 - return payload of u64 attribute
1630  * @nla: u64 netlink attribute
1631  */
nla_get_u64(const struct nlattr * nla)1632 static inline u64 nla_get_u64(const struct nlattr *nla)
1633 {
1634 	u64 tmp;
1635 
1636 	nla_memcpy(&tmp, nla, sizeof(tmp));
1637 
1638 	return tmp;
1639 }
1640 
1641 /**
1642  * nla_get_be64 - return payload of __be64 attribute
1643  * @nla: __be64 netlink attribute
1644  */
nla_get_be64(const struct nlattr * nla)1645 static inline __be64 nla_get_be64(const struct nlattr *nla)
1646 {
1647 	__be64 tmp;
1648 
1649 	nla_memcpy(&tmp, nla, sizeof(tmp));
1650 
1651 	return tmp;
1652 }
1653 
1654 /**
1655  * nla_get_le64 - return payload of __le64 attribute
1656  * @nla: __le64 netlink attribute
1657  */
nla_get_le64(const struct nlattr * nla)1658 static inline __le64 nla_get_le64(const struct nlattr *nla)
1659 {
1660 	return *(__le64 *) nla_data(nla);
1661 }
1662 
1663 /**
1664  * nla_get_s32 - return payload of s32 attribute
1665  * @nla: s32 netlink attribute
1666  */
nla_get_s32(const struct nlattr * nla)1667 static inline s32 nla_get_s32(const struct nlattr *nla)
1668 {
1669 	return *(s32 *) nla_data(nla);
1670 }
1671 
1672 /**
1673  * nla_get_s16 - return payload of s16 attribute
1674  * @nla: s16 netlink attribute
1675  */
nla_get_s16(const struct nlattr * nla)1676 static inline s16 nla_get_s16(const struct nlattr *nla)
1677 {
1678 	return *(s16 *) nla_data(nla);
1679 }
1680 
1681 /**
1682  * nla_get_s8 - return payload of s8 attribute
1683  * @nla: s8 netlink attribute
1684  */
nla_get_s8(const struct nlattr * nla)1685 static inline s8 nla_get_s8(const struct nlattr *nla)
1686 {
1687 	return *(s8 *) nla_data(nla);
1688 }
1689 
1690 /**
1691  * nla_get_s64 - return payload of s64 attribute
1692  * @nla: s64 netlink attribute
1693  */
nla_get_s64(const struct nlattr * nla)1694 static inline s64 nla_get_s64(const struct nlattr *nla)
1695 {
1696 	s64 tmp;
1697 
1698 	nla_memcpy(&tmp, nla, sizeof(tmp));
1699 
1700 	return tmp;
1701 }
1702 
1703 /**
1704  * nla_get_flag - return payload of flag attribute
1705  * @nla: flag netlink attribute
1706  */
nla_get_flag(const struct nlattr * nla)1707 static inline int nla_get_flag(const struct nlattr *nla)
1708 {
1709 	return !!nla;
1710 }
1711 
1712 /**
1713  * nla_get_msecs - return payload of msecs attribute
1714  * @nla: msecs netlink attribute
1715  *
1716  * Returns the number of milliseconds in jiffies.
1717  */
nla_get_msecs(const struct nlattr * nla)1718 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1719 {
1720 	u64 msecs = nla_get_u64(nla);
1721 
1722 	return msecs_to_jiffies((unsigned long) msecs);
1723 }
1724 
1725 /**
1726  * nla_get_in_addr - return payload of IPv4 address attribute
1727  * @nla: IPv4 address netlink attribute
1728  */
nla_get_in_addr(const struct nlattr * nla)1729 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1730 {
1731 	return *(__be32 *) nla_data(nla);
1732 }
1733 
1734 /**
1735  * nla_get_in6_addr - return payload of IPv6 address attribute
1736  * @nla: IPv6 address netlink attribute
1737  */
nla_get_in6_addr(const struct nlattr * nla)1738 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1739 {
1740 	struct in6_addr tmp;
1741 
1742 	nla_memcpy(&tmp, nla, sizeof(tmp));
1743 	return tmp;
1744 }
1745 
1746 /**
1747  * nla_get_bitfield32 - return payload of 32 bitfield attribute
1748  * @nla: nla_bitfield32 attribute
1749  */
nla_get_bitfield32(const struct nlattr * nla)1750 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1751 {
1752 	struct nla_bitfield32 tmp;
1753 
1754 	nla_memcpy(&tmp, nla, sizeof(tmp));
1755 	return tmp;
1756 }
1757 
1758 /**
1759  * nla_memdup - duplicate attribute memory (kmemdup)
1760  * @src: netlink attribute to duplicate from
1761  * @gfp: GFP mask
1762  */
nla_memdup(const struct nlattr * src,gfp_t gfp)1763 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1764 {
1765 	return kmemdup(nla_data(src), nla_len(src), gfp);
1766 }
1767 
1768 /**
1769  * nla_nest_start_noflag - Start a new level of nested attributes
1770  * @skb: socket buffer to add attributes to
1771  * @attrtype: attribute type of container
1772  *
1773  * This function exists for backward compatibility to use in APIs which never
1774  * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1775  * nla_nest_start() which sets the flag.
1776  *
1777  * Returns the container attribute or NULL on error
1778  */
nla_nest_start_noflag(struct sk_buff * skb,int attrtype)1779 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1780 						   int attrtype)
1781 {
1782 	struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1783 
1784 	if (nla_put(skb, attrtype, 0, NULL) < 0)
1785 		return NULL;
1786 
1787 	return start;
1788 }
1789 
1790 /**
1791  * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1792  * @skb: socket buffer to add attributes to
1793  * @attrtype: attribute type of container
1794  *
1795  * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1796  * flag. This is the preferred function to use in new code.
1797  *
1798  * Returns the container attribute or NULL on error
1799  */
nla_nest_start(struct sk_buff * skb,int attrtype)1800 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1801 {
1802 	return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1803 }
1804 
1805 /**
1806  * nla_nest_end - Finalize nesting of attributes
1807  * @skb: socket buffer the attributes are stored in
1808  * @start: container attribute
1809  *
1810  * Corrects the container attribute header to include the all
1811  * appeneded attributes.
1812  *
1813  * Returns the total data length of the skb.
1814  */
nla_nest_end(struct sk_buff * skb,struct nlattr * start)1815 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1816 {
1817 	start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1818 	return skb->len;
1819 }
1820 
1821 /**
1822  * nla_nest_cancel - Cancel nesting of attributes
1823  * @skb: socket buffer the message is stored in
1824  * @start: container attribute
1825  *
1826  * Removes the container attribute and including all nested
1827  * attributes. Returns -EMSGSIZE
1828  */
nla_nest_cancel(struct sk_buff * skb,struct nlattr * start)1829 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1830 {
1831 	nlmsg_trim(skb, start);
1832 }
1833 
1834 /**
1835  * __nla_validate_nested - Validate a stream of nested attributes
1836  * @start: container attribute
1837  * @maxtype: maximum attribute type to be expected
1838  * @policy: validation policy
1839  * @validate: validation strictness
1840  * @extack: extended ACK report struct
1841  *
1842  * Validates all attributes in the nested attribute stream against the
1843  * specified policy. Attributes with a type exceeding maxtype will be
1844  * ignored. See documenation of struct nla_policy for more details.
1845  *
1846  * Returns 0 on success or a negative error code.
1847  */
__nla_validate_nested(const struct nlattr * start,int maxtype,const struct nla_policy * policy,unsigned int validate,struct netlink_ext_ack * extack)1848 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1849 					const struct nla_policy *policy,
1850 					unsigned int validate,
1851 					struct netlink_ext_ack *extack)
1852 {
1853 	return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1854 			      validate, extack);
1855 }
1856 
1857 static inline int
nla_validate_nested(const struct nlattr * start,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)1858 nla_validate_nested(const struct nlattr *start, int maxtype,
1859 		    const struct nla_policy *policy,
1860 		    struct netlink_ext_ack *extack)
1861 {
1862 	return __nla_validate_nested(start, maxtype, policy,
1863 				     NL_VALIDATE_STRICT, extack);
1864 }
1865 
1866 static inline int
nla_validate_nested_deprecated(const struct nlattr * start,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)1867 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1868 			       const struct nla_policy *policy,
1869 			       struct netlink_ext_ack *extack)
1870 {
1871 	return __nla_validate_nested(start, maxtype, policy,
1872 				     NL_VALIDATE_LIBERAL, extack);
1873 }
1874 
1875 /**
1876  * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1877  * @skb: socket buffer the message is stored in
1878  *
1879  * Return true if padding is needed to align the next attribute (nla_data()) to
1880  * a 64-bit aligned area.
1881  */
nla_need_padding_for_64bit(struct sk_buff * skb)1882 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1883 {
1884 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1885 	/* The nlattr header is 4 bytes in size, that's why we test
1886 	 * if the skb->data _is_ aligned.  A NOP attribute, plus
1887 	 * nlattr header for next attribute, will make nla_data()
1888 	 * 8-byte aligned.
1889 	 */
1890 	if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1891 		return true;
1892 #endif
1893 	return false;
1894 }
1895 
1896 /**
1897  * nla_align_64bit - 64-bit align the nla_data() of next attribute
1898  * @skb: socket buffer the message is stored in
1899  * @padattr: attribute type for the padding
1900  *
1901  * Conditionally emit a padding netlink attribute in order to make
1902  * the next attribute we emit have a 64-bit aligned nla_data() area.
1903  * This will only be done in architectures which do not have
1904  * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1905  *
1906  * Returns zero on success or a negative error code.
1907  */
nla_align_64bit(struct sk_buff * skb,int padattr)1908 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1909 {
1910 	if (nla_need_padding_for_64bit(skb) &&
1911 	    !nla_reserve(skb, padattr, 0))
1912 		return -EMSGSIZE;
1913 
1914 	return 0;
1915 }
1916 
1917 /**
1918  * nla_total_size_64bit - total length of attribute including padding
1919  * @payload: length of payload
1920  */
nla_total_size_64bit(int payload)1921 static inline int nla_total_size_64bit(int payload)
1922 {
1923 	return NLA_ALIGN(nla_attr_size(payload))
1924 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1925 		+ NLA_ALIGN(nla_attr_size(0))
1926 #endif
1927 		;
1928 }
1929 
1930 /**
1931  * nla_for_each_attr - iterate over a stream of attributes
1932  * @pos: loop counter, set to current attribute
1933  * @head: head of attribute stream
1934  * @len: length of attribute stream
1935  * @rem: initialized to len, holds bytes currently remaining in stream
1936  */
1937 #define nla_for_each_attr(pos, head, len, rem) \
1938 	for (pos = head, rem = len; \
1939 	     nla_ok(pos, rem); \
1940 	     pos = nla_next(pos, &(rem)))
1941 
1942 /**
1943  * nla_for_each_nested - iterate over nested attributes
1944  * @pos: loop counter, set to current attribute
1945  * @nla: attribute containing the nested attributes
1946  * @rem: initialized to len, holds bytes currently remaining in stream
1947  */
1948 #define nla_for_each_nested(pos, nla, rem) \
1949 	nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1950 
1951 /**
1952  * nla_is_last - Test if attribute is last in stream
1953  * @nla: attribute to test
1954  * @rem: bytes remaining in stream
1955  */
nla_is_last(const struct nlattr * nla,int rem)1956 static inline bool nla_is_last(const struct nlattr *nla, int rem)
1957 {
1958 	return nla->nla_len == rem;
1959 }
1960 
1961 void nla_get_range_unsigned(const struct nla_policy *pt,
1962 			    struct netlink_range_validation *range);
1963 void nla_get_range_signed(const struct nla_policy *pt,
1964 			  struct netlink_range_validation_signed *range);
1965 
1966 struct netlink_policy_dump_state;
1967 
1968 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
1969 				   const struct nla_policy *policy,
1970 				   unsigned int maxtype);
1971 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
1972 				       const struct nla_policy *policy,
1973 				       unsigned int maxtype);
1974 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
1975 int netlink_policy_dump_write(struct sk_buff *skb,
1976 			      struct netlink_policy_dump_state *state);
1977 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
1978 int netlink_policy_dump_write_attr(struct sk_buff *skb,
1979 				   const struct nla_policy *pt,
1980 				   int nestattr);
1981 void netlink_policy_dump_free(struct netlink_policy_dump_state *state);
1982 
1983 #endif
1984