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