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_uint(nla) get payload for a uint attribute
132 * nla_get_sint(nla) get payload for a sint attribute
133 * nla_get_u8(nla) get payload for a u8 attribute
134 * nla_get_u16(nla) get payload for a u16 attribute
135 * nla_get_u32(nla) get payload for a u32 attribute
136 * nla_get_u64(nla) get payload for a u64 attribute
137 * nla_get_s8(nla) get payload for a s8 attribute
138 * nla_get_s16(nla) get payload for a s16 attribute
139 * nla_get_s32(nla) get payload for a s32 attribute
140 * nla_get_s64(nla) get payload for a s64 attribute
141 * nla_get_flag(nla) return 1 if flag is true
142 * nla_get_msecs(nla) get payload for a msecs attribute
143 *
144 * Attribute Misc:
145 * nla_memcpy(dest, nla, count) copy attribute into memory
146 * nla_memcmp(nla, data, size) compare attribute with memory area
147 * nla_strscpy(dst, nla, size) copy attribute to a sized string
148 * nla_strcmp(nla, str) compare attribute with string
149 *
150 * Attribute Parsing:
151 * nla_ok(nla, remaining) does nla fit into remaining bytes?
152 * nla_next(nla, remaining) get next netlink attribute
153 * nla_validate() validate a stream of attributes
154 * nla_validate_nested() validate a stream of nested attributes
155 * nla_find() find attribute in stream of attributes
156 * nla_find_nested() find attribute in nested attributes
157 * nla_parse() parse and validate stream of attrs
158 * nla_parse_nested() parse nested attributes
159 * nla_for_each_attr() loop over all attributes
160 * nla_for_each_nested() loop over the nested attributes
161 *=========================================================================
162 */
163
164 /**
165 * Standard attribute types to specify validation policy
166 */
167enum {
168 NLA_UNSPEC,
169 NLA_U8,
170 NLA_U16,
171 NLA_U32,
172 NLA_U64,
173 NLA_STRING,
174 NLA_FLAG,
175 NLA_MSECS,
176 NLA_NESTED,
177 NLA_NESTED_ARRAY,
178 NLA_NUL_STRING,
179 NLA_BINARY,
180 NLA_S8,
181 NLA_S16,
182 NLA_S32,
183 NLA_S64,
184 NLA_BITFIELD32,
185 NLA_REJECT,
186 NLA_BE16,
187 NLA_BE32,
188 NLA_SINT,
189 NLA_UINT,
190 __NLA_TYPE_MAX,
191};
192
193#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
194
195struct netlink_range_validation {
196 u64 min, max;
197};
198
199struct netlink_range_validation_signed {
200 s64 min, max;
201};
202
203enum nla_policy_validation {
204 NLA_VALIDATE_NONE,
205 NLA_VALIDATE_RANGE,
206 NLA_VALIDATE_RANGE_WARN_TOO_LONG,
207 NLA_VALIDATE_MIN,
208 NLA_VALIDATE_MAX,
209 NLA_VALIDATE_MASK,
210 NLA_VALIDATE_RANGE_PTR,
211 NLA_VALIDATE_FUNCTION,
212};
213
214/**
215 * struct nla_policy - attribute validation policy
216 * @type: Type of attribute or NLA_UNSPEC
217 * @validation_type: type of attribute validation done in addition to
218 * type-specific validation (e.g. range, function call), see
219 * &enum nla_policy_validation
220 * @len: Type specific length of payload
221 *
222 * Policies are defined as arrays of this struct, the array must be
223 * accessible by attribute type up to the highest identifier to be expected.
224 *
225 * Meaning of `len' field:
226 * NLA_STRING Maximum length of string
227 * NLA_NUL_STRING Maximum length of string (excluding NUL)
228 * NLA_FLAG Unused
229 * NLA_BINARY Maximum length of attribute payload
230 * (but see also below with the validation type)
231 * NLA_NESTED,
232 * NLA_NESTED_ARRAY Length verification is done by checking len of
233 * nested header (or empty); len field is used if
234 * nested_policy is also used, for the max attr
235 * number in the nested policy.
236 * NLA_SINT, NLA_UINT,
237 * NLA_U8, NLA_U16,
238 * NLA_U32, NLA_U64,
239 * NLA_S8, NLA_S16,
240 * NLA_S32, NLA_S64,
241 * NLA_BE16, NLA_BE32,
242 * NLA_MSECS Leaving the length field zero will verify the
243 * given type fits, using it verifies minimum length
244 * just like "All other"
245 * NLA_BITFIELD32 Unused
246 * NLA_REJECT Unused
247 * All other Minimum length of attribute payload
248 *
249 * Meaning of validation union:
250 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and
251 * `bitfield32_valid' is the u32 value of valid flags
252 * NLA_REJECT This attribute is always rejected and `reject_message'
253 * may point to a string to report as the error instead
254 * of the generic one in extended ACK.
255 * NLA_NESTED `nested_policy' to a nested policy to validate, must
256 * also set `len' to the max attribute number. Use the
257 * provided NLA_POLICY_NESTED() macro.
258 * Note that nla_parse() will validate, but of course not
259 * parse, the nested sub-policies.
260 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate,
261 * must also set `len' to the max attribute number. Use
262 * the provided NLA_POLICY_NESTED_ARRAY() macro.
263 * The difference to NLA_NESTED is the structure:
264 * NLA_NESTED has the nested attributes directly inside
265 * while an array has the nested attributes at another
266 * level down and the attribute types directly in the
267 * nesting don't matter.
268 * NLA_UINT,
269 * NLA_U8,
270 * NLA_U16,
271 * NLA_U32,
272 * NLA_U64,
273 * NLA_BE16,
274 * NLA_BE32,
275 * NLA_SINT,
276 * NLA_S8,
277 * NLA_S16,
278 * NLA_S32,
279 * NLA_S64 The `min' and `max' fields are used depending on the
280 * validation_type field, if that is min/max/range then
281 * the min, max or both are used (respectively) to check
282 * the value of the integer attribute.
283 * Note that in the interest of code simplicity and
284 * struct size both limits are s16, so you cannot
285 * enforce a range that doesn't fall within the range
286 * of s16 - do that using the NLA_POLICY_FULL_RANGE()
287 * or NLA_POLICY_FULL_RANGE_SIGNED() macros instead.
288 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
289 * NLA_POLICY_RANGE() macros.
290 * NLA_UINT,
291 * NLA_U8,
292 * NLA_U16,
293 * NLA_U32,
294 * NLA_U64 If the validation_type field instead is set to
295 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
296 * to a struct netlink_range_validation that indicates
297 * the min/max values.
298 * Use NLA_POLICY_FULL_RANGE().
299 * NLA_SINT,
300 * NLA_S8,
301 * NLA_S16,
302 * NLA_S32,
303 * NLA_S64 If the validation_type field instead is set to
304 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
305 * pointer to a struct netlink_range_validation_signed
306 * that indicates the min/max values.
307 * Use NLA_POLICY_FULL_RANGE_SIGNED().
308 *
309 * NLA_BINARY If the validation type is like the ones for integers
310 * above, then the min/max length (not value like for
311 * integers) of the attribute is enforced.
312 *
313 * All other Unused - but note that it's a union
314 *
315 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
316 * NLA_BINARY Validation function called for the attribute.
317 * All other Unused - but note that it's a union
318 *
319 * Example:
320 *
321 * static const u32 myvalidflags = 0xff231023;
322 *
323 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
324 * [ATTR_FOO] = { .type = NLA_U16 },
325 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
326 * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)),
327 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
328 * };
329 */
330struct nla_policy {
331 u8 type;
332 u8 validation_type;
333 u16 len;
334 union {
335 /**
336 * @strict_start_type: first attribute to validate strictly
337 *
338 * This entry is special, and used for the attribute at index 0
339 * only, and specifies special data about the policy, namely it
340 * specifies the "boundary type" where strict length validation
341 * starts for any attribute types >= this value, also, strict
342 * nesting validation starts here.
343 *
344 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
345 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to
346 * get the previous pure { .len = xyz } behaviour. The advantage
347 * of this is that types not specified in the policy will be
348 * rejected.
349 *
350 * For completely new families it should be set to 1 so that the
351 * validation is enforced for all attributes. For existing ones
352 * it should be set at least when new attributes are added to
353 * the enum used by the policy, and be set to the new value that
354 * was added to enforce strict validation from thereon.
355 */
356 u16 strict_start_type;
357
358 /* private: use NLA_POLICY_*() to set */
359 const u32 bitfield32_valid;
360 const u32 mask;
361 const char *reject_message;
362 const struct nla_policy *nested_policy;
363 const struct netlink_range_validation *range;
364 const struct netlink_range_validation_signed *range_signed;
365 struct {
366 s16 min, max;
367 };
368 int (*validate)(const struct nlattr *attr,
369 struct netlink_ext_ack *extack);
370 };
371};
372
373#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN)
374#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
375
376#define _NLA_POLICY_NESTED(maxattr, policy) \
377 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
378#define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
379 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
380#define NLA_POLICY_NESTED(policy) \
381 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
382#define NLA_POLICY_NESTED_ARRAY(policy) \
383 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
384#define NLA_POLICY_BITFIELD32(valid) \
385 { .type = NLA_BITFIELD32, .bitfield32_valid = valid }
386
387#define __NLA_IS_UINT_TYPE(tp) \
388 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || \
389 tp == NLA_U64 || tp == NLA_UINT || \
390 tp == NLA_BE16 || tp == NLA_BE32)
391#define __NLA_IS_SINT_TYPE(tp) \
392 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64 || \
393 tp == NLA_SINT)
394
395#define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
396#define NLA_ENSURE_UINT_TYPE(tp) \
397 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
398#define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \
399 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
400 tp == NLA_MSECS || \
401 tp == NLA_BINARY) + tp)
402#define NLA_ENSURE_SINT_TYPE(tp) \
403 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
404#define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \
405 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
406 __NLA_IS_SINT_TYPE(tp) || \
407 tp == NLA_MSECS || \
408 tp == NLA_BINARY) + tp)
409#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
410 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \
411 tp != NLA_REJECT && \
412 tp != NLA_NESTED && \
413 tp != NLA_NESTED_ARRAY) + tp)
414
415#define NLA_POLICY_RANGE(tp, _min, _max) { \
416 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
417 .validation_type = NLA_VALIDATE_RANGE, \
418 .min = _min, \
419 .max = _max \
420}
421
422#define NLA_POLICY_FULL_RANGE(tp, _range) { \
423 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \
424 .validation_type = NLA_VALIDATE_RANGE_PTR, \
425 .range = _range, \
426}
427
428#define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \
429 .type = NLA_ENSURE_SINT_TYPE(tp), \
430 .validation_type = NLA_VALIDATE_RANGE_PTR, \
431 .range_signed = _range, \
432}
433
434#define NLA_POLICY_MIN(tp, _min) { \
435 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
436 .validation_type = NLA_VALIDATE_MIN, \
437 .min = _min, \
438}
439
440#define NLA_POLICY_MAX(tp, _max) { \
441 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
442 .validation_type = NLA_VALIDATE_MAX, \
443 .max = _max, \
444}
445
446#define NLA_POLICY_MASK(tp, _mask) { \
447 .type = NLA_ENSURE_UINT_TYPE(tp), \
448 .validation_type = NLA_VALIDATE_MASK, \
449 .mask = _mask, \
450}
451
452#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \
453 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \
454 .validation_type = NLA_VALIDATE_FUNCTION, \
455 .validate = fn, \
456 .len = __VA_ARGS__ + 0, \
457}
458
459#define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
460#define NLA_POLICY_EXACT_LEN_WARN(_len) { \
461 .type = NLA_BINARY, \
462 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \
463 .min = _len, \
464 .max = _len \
465}
466#define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len)
467
468/**
469 * struct nl_info - netlink source information
470 * @nlh: Netlink message header of original request
471 * @nl_net: Network namespace
472 * @portid: Netlink PORTID of requesting application
473 * @skip_notify: Skip netlink notifications to user space
474 * @skip_notify_kernel: Skip selected in-kernel notifications
475 */
476struct nl_info {
477 struct nlmsghdr *nlh;
478 struct net *nl_net;
479 u32 portid;
480 u8 skip_notify:1,
481 skip_notify_kernel:1;
482};
483
484/**
485 * enum netlink_validation - netlink message/attribute validation levels
486 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
487 * extra data at the end of the message, attributes being longer than
488 * they should be, or unknown attributes being present.
489 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
490 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
491 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
492 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
493 * This can safely be set by the kernel when the given policy has no
494 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
495 * are enforced going forward.
496 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
497 * U8, U16, U32 must have exact size, etc.)
498 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
499 * and unset for other policies.
500 */
501enum netlink_validation {
502 NL_VALIDATE_LIBERAL = 0,
503 NL_VALIDATE_TRAILING = BIT(0),
504 NL_VALIDATE_MAXTYPE = BIT(1),
505 NL_VALIDATE_UNSPEC = BIT(2),
506 NL_VALIDATE_STRICT_ATTRS = BIT(3),
507 NL_VALIDATE_NESTED = BIT(4),
508};
509
510#define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
511 NL_VALIDATE_MAXTYPE)
512#define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
513 NL_VALIDATE_MAXTYPE |\
514 NL_VALIDATE_UNSPEC |\
515 NL_VALIDATE_STRICT_ATTRS |\
516 NL_VALIDATE_NESTED)
517
518int netlink_rcv_skb(struct sk_buff *skb,
519 int (*cb)(struct sk_buff *, struct nlmsghdr *,
520 struct netlink_ext_ack *));
521int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
522 unsigned int group, int report, gfp_t flags);
523
524int __nla_validate(const struct nlattr *head, int len, int maxtype,
525 const struct nla_policy *policy, unsigned int validate,
526 struct netlink_ext_ack *extack);
527int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
528 int len, const struct nla_policy *policy, unsigned int validate,
529 struct netlink_ext_ack *extack);
530int nla_policy_len(const struct nla_policy *, int);
531struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
532ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
533char *nla_strdup(const struct nlattr *nla, gfp_t flags);
534int nla_memcpy(void *dest, const struct nlattr *src, int count);
535int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
536int nla_strcmp(const struct nlattr *nla, const char *str);
537struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
538struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
539 int attrlen, int padattr);
540void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
541struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
542struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
543 int attrlen, int padattr);
544void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
545void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
546 const void *data);
547void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
548 const void *data, int padattr);
549void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
550int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
551int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
552 const void *data, int padattr);
553int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
554int nla_append(struct sk_buff *skb, int attrlen, const void *data);
555
556/**************************************************************************
557 * Netlink Messages
558 **************************************************************************/
559
560/**
561 * nlmsg_msg_size - length of netlink message not including padding
562 * @payload: length of message payload
563 */
564static inline int nlmsg_msg_size(int payload)
565{
566 return NLMSG_HDRLEN + payload;
567}
568
569/**
570 * nlmsg_total_size - length of netlink message including padding
571 * @payload: length of message payload
572 */
573static inline int nlmsg_total_size(int payload)
574{
575 return NLMSG_ALIGN(nlmsg_msg_size(payload));
576}
577
578/**
579 * nlmsg_padlen - length of padding at the message's tail
580 * @payload: length of message payload
581 */
582static inline int nlmsg_padlen(int payload)
583{
584 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
585}
586
587/**
588 * nlmsg_data - head of message payload
589 * @nlh: netlink message header
590 */
591static inline void *nlmsg_data(const struct nlmsghdr *nlh)
592{
593 return (unsigned char *) nlh + NLMSG_HDRLEN;
594}
595
596/**
597 * nlmsg_len - length of message payload
598 * @nlh: netlink message header
599 */
600static inline int nlmsg_len(const struct nlmsghdr *nlh)
601{
602 return nlh->nlmsg_len - NLMSG_HDRLEN;
603}
604
605/**
606 * nlmsg_attrdata - head of attributes data
607 * @nlh: netlink message header
608 * @hdrlen: length of family specific header
609 */
610static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
611 int hdrlen)
612{
613 unsigned char *data = nlmsg_data(nlh);
614 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
615}
616
617/**
618 * nlmsg_attrlen - length of attributes data
619 * @nlh: netlink message header
620 * @hdrlen: length of family specific header
621 */
622static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
623{
624 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
625}
626
627/**
628 * nlmsg_ok - check if the netlink message fits into the remaining bytes
629 * @nlh: netlink message header
630 * @remaining: number of bytes remaining in message stream
631 */
632static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
633{
634 return (remaining >= (int) sizeof(struct nlmsghdr) &&
635 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
636 nlh->nlmsg_len <= remaining);
637}
638
639/**
640 * nlmsg_next - next netlink message in message stream
641 * @nlh: netlink message header
642 * @remaining: number of bytes remaining in message stream
643 *
644 * Returns the next netlink message in the message stream and
645 * decrements remaining by the size of the current message.
646 */
647static inline struct nlmsghdr *
648nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
649{
650 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
651
652 *remaining -= totlen;
653
654 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
655}
656
657/**
658 * nla_parse - Parse a stream of attributes into a tb buffer
659 * @tb: destination array with maxtype+1 elements
660 * @maxtype: maximum attribute type to be expected
661 * @head: head of attribute stream
662 * @len: length of attribute stream
663 * @policy: validation policy
664 * @extack: extended ACK pointer
665 *
666 * Parses a stream of attributes and stores a pointer to each attribute in
667 * the tb array accessible via the attribute type. Attributes with a type
668 * exceeding maxtype will be rejected, policy must be specified, attributes
669 * will be validated in the strictest way possible.
670 *
671 * Returns 0 on success or a negative error code.
672 */
673static inline int nla_parse(struct nlattr **tb, int maxtype,
674 const struct nlattr *head, int len,
675 const struct nla_policy *policy,
676 struct netlink_ext_ack *extack)
677{
678 return __nla_parse(tb, maxtype, head, len, policy,
679 NL_VALIDATE_STRICT, extack);
680}
681
682/**
683 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
684 * @tb: destination array with maxtype+1 elements
685 * @maxtype: maximum attribute type to be expected
686 * @head: head of attribute stream
687 * @len: length of attribute stream
688 * @policy: validation policy
689 * @extack: extended ACK pointer
690 *
691 * Parses a stream of attributes and stores a pointer to each attribute in
692 * the tb array accessible via the attribute type. Attributes with a type
693 * exceeding maxtype will be ignored and attributes from the policy are not
694 * always strictly validated (only for new attributes).
695 *
696 * Returns 0 on success or a negative error code.
697 */
698static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
699 const struct nlattr *head, int len,
700 const struct nla_policy *policy,
701 struct netlink_ext_ack *extack)
702{
703 return __nla_parse(tb, maxtype, head, len, policy,
704 validate: NL_VALIDATE_LIBERAL, extack);
705}
706
707/**
708 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
709 * @tb: destination array with maxtype+1 elements
710 * @maxtype: maximum attribute type to be expected
711 * @head: head of attribute stream
712 * @len: length of attribute stream
713 * @policy: validation policy
714 * @extack: extended ACK pointer
715 *
716 * Parses a stream of attributes and stores a pointer to each attribute in
717 * the tb array accessible via the attribute type. Attributes with a type
718 * exceeding maxtype will be rejected as well as trailing data, but the
719 * policy is not completely strictly validated (only for new attributes).
720 *
721 * Returns 0 on success or a negative error code.
722 */
723static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
724 const struct nlattr *head,
725 int len,
726 const struct nla_policy *policy,
727 struct netlink_ext_ack *extack)
728{
729 return __nla_parse(tb, maxtype, head, len, policy,
730 NL_VALIDATE_DEPRECATED_STRICT, extack);
731}
732
733/**
734 * __nlmsg_parse - parse attributes of a netlink message
735 * @nlh: netlink message header
736 * @hdrlen: length of family specific header
737 * @tb: destination array with maxtype+1 elements
738 * @maxtype: maximum attribute type to be expected
739 * @policy: validation policy
740 * @validate: validation strictness
741 * @extack: extended ACK report struct
742 *
743 * See nla_parse()
744 */
745static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
746 struct nlattr *tb[], int maxtype,
747 const struct nla_policy *policy,
748 unsigned int validate,
749 struct netlink_ext_ack *extack)
750{
751 if (nlh->nlmsg_len < nlmsg_msg_size(payload: hdrlen)) {
752 NL_SET_ERR_MSG(extack, "Invalid header length");
753 return -EINVAL;
754 }
755
756 return __nla_parse(tb, maxtype, head: nlmsg_attrdata(nlh, hdrlen),
757 len: nlmsg_attrlen(nlh, hdrlen), policy, validate,
758 extack);
759}
760
761/**
762 * nlmsg_parse - parse attributes of a netlink message
763 * @nlh: netlink message header
764 * @hdrlen: length of family specific header
765 * @tb: destination array with maxtype+1 elements
766 * @maxtype: maximum attribute type to be expected
767 * @policy: validation policy
768 * @extack: extended ACK report struct
769 *
770 * See nla_parse()
771 */
772static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
773 struct nlattr *tb[], int maxtype,
774 const struct nla_policy *policy,
775 struct netlink_ext_ack *extack)
776{
777 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
778 NL_VALIDATE_STRICT, extack);
779}
780
781/**
782 * nlmsg_parse_deprecated - parse attributes of a netlink message
783 * @nlh: netlink message header
784 * @hdrlen: length of family specific header
785 * @tb: destination array with maxtype+1 elements
786 * @maxtype: maximum attribute type to be expected
787 * @policy: validation policy
788 * @extack: extended ACK report struct
789 *
790 * See nla_parse_deprecated()
791 */
792static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
793 struct nlattr *tb[], int maxtype,
794 const struct nla_policy *policy,
795 struct netlink_ext_ack *extack)
796{
797 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
798 validate: NL_VALIDATE_LIBERAL, extack);
799}
800
801/**
802 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
803 * @nlh: netlink message header
804 * @hdrlen: length of family specific header
805 * @tb: destination array with maxtype+1 elements
806 * @maxtype: maximum attribute type to be expected
807 * @policy: validation policy
808 * @extack: extended ACK report struct
809 *
810 * See nla_parse_deprecated_strict()
811 */
812static inline int
813nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
814 struct nlattr *tb[], int maxtype,
815 const struct nla_policy *policy,
816 struct netlink_ext_ack *extack)
817{
818 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
819 NL_VALIDATE_DEPRECATED_STRICT, extack);
820}
821
822/**
823 * nlmsg_find_attr - find a specific attribute in a netlink message
824 * @nlh: netlink message header
825 * @hdrlen: length of familiy specific header
826 * @attrtype: type of attribute to look for
827 *
828 * Returns the first attribute which matches the specified type.
829 */
830static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
831 int hdrlen, int attrtype)
832{
833 return nla_find(head: nlmsg_attrdata(nlh, hdrlen),
834 len: nlmsg_attrlen(nlh, hdrlen), attrtype);
835}
836
837/**
838 * nla_validate_deprecated - Validate a stream of attributes
839 * @head: head of attribute stream
840 * @len: length of attribute stream
841 * @maxtype: maximum attribute type to be expected
842 * @policy: validation policy
843 * @extack: extended ACK report struct
844 *
845 * Validates all attributes in the specified attribute stream against the
846 * specified policy. Validation is done in liberal mode.
847 * See documenation of struct nla_policy for more details.
848 *
849 * Returns 0 on success or a negative error code.
850 */
851static inline int nla_validate_deprecated(const struct nlattr *head, int len,
852 int maxtype,
853 const struct nla_policy *policy,
854 struct netlink_ext_ack *extack)
855{
856 return __nla_validate(head, len, maxtype, policy, validate: NL_VALIDATE_LIBERAL,
857 extack);
858}
859
860/**
861 * nla_validate - Validate a stream of attributes
862 * @head: head of attribute stream
863 * @len: length of attribute stream
864 * @maxtype: maximum attribute type to be expected
865 * @policy: validation policy
866 * @extack: extended ACK report struct
867 *
868 * Validates all attributes in the specified attribute stream against the
869 * specified policy. Validation is done in strict mode.
870 * See documenation of struct nla_policy for more details.
871 *
872 * Returns 0 on success or a negative error code.
873 */
874static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
875 const struct nla_policy *policy,
876 struct netlink_ext_ack *extack)
877{
878 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
879 extack);
880}
881
882/**
883 * nlmsg_validate_deprecated - validate a netlink message including attributes
884 * @nlh: netlinket message header
885 * @hdrlen: length of familiy specific header
886 * @maxtype: maximum attribute type to be expected
887 * @policy: validation policy
888 * @extack: extended ACK report struct
889 */
890static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
891 int hdrlen, int maxtype,
892 const struct nla_policy *policy,
893 struct netlink_ext_ack *extack)
894{
895 if (nlh->nlmsg_len < nlmsg_msg_size(payload: hdrlen))
896 return -EINVAL;
897
898 return __nla_validate(head: nlmsg_attrdata(nlh, hdrlen),
899 len: nlmsg_attrlen(nlh, hdrlen), maxtype,
900 policy, validate: NL_VALIDATE_LIBERAL, extack);
901}
902
903
904
905/**
906 * nlmsg_report - need to report back to application?
907 * @nlh: netlink message header
908 *
909 * Returns 1 if a report back to the application is requested.
910 */
911static inline int nlmsg_report(const struct nlmsghdr *nlh)
912{
913 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
914}
915
916/**
917 * nlmsg_seq - return the seq number of netlink message
918 * @nlh: netlink message header
919 *
920 * Returns 0 if netlink message is NULL
921 */
922static inline u32 nlmsg_seq(const struct nlmsghdr *nlh)
923{
924 return nlh ? nlh->nlmsg_seq : 0;
925}
926
927/**
928 * nlmsg_for_each_attr - iterate over a stream of attributes
929 * @pos: loop counter, set to current attribute
930 * @nlh: netlink message header
931 * @hdrlen: length of familiy specific header
932 * @rem: initialized to len, holds bytes currently remaining in stream
933 */
934#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
935 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
936 nlmsg_attrlen(nlh, hdrlen), rem)
937
938/**
939 * nlmsg_put - Add a new netlink message to an skb
940 * @skb: socket buffer to store message in
941 * @portid: netlink PORTID of requesting application
942 * @seq: sequence number of message
943 * @type: message type
944 * @payload: length of message payload
945 * @flags: message flags
946 *
947 * Returns NULL if the tailroom of the skb is insufficient to store
948 * the message header and payload.
949 */
950static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
951 int type, int payload, int flags)
952{
953 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
954 return NULL;
955
956 return __nlmsg_put(skb, portid, seq, type, len: payload, flags);
957}
958
959/**
960 * nlmsg_append - Add more data to a nlmsg in a skb
961 * @skb: socket buffer to store message in
962 * @size: length of message payload
963 *
964 * Append data to an existing nlmsg, used when constructing a message
965 * with multiple fixed-format headers (which is rare).
966 * Returns NULL if the tailroom of the skb is insufficient to store
967 * the extra payload.
968 */
969static inline void *nlmsg_append(struct sk_buff *skb, u32 size)
970{
971 if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size)))
972 return NULL;
973
974 if (NLMSG_ALIGN(size) - size)
975 memset(skb_tail_pointer(skb) + size, 0,
976 NLMSG_ALIGN(size) - size);
977 return __skb_put(skb, NLMSG_ALIGN(size));
978}
979
980/**
981 * nlmsg_put_answer - Add a new callback based netlink message to an skb
982 * @skb: socket buffer to store message in
983 * @cb: netlink callback
984 * @type: message type
985 * @payload: length of message payload
986 * @flags: message flags
987 *
988 * Returns NULL if the tailroom of the skb is insufficient to store
989 * the message header and payload.
990 */
991static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
992 struct netlink_callback *cb,
993 int type, int payload,
994 int flags)
995{
996 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, seq: cb->nlh->nlmsg_seq,
997 type, payload, flags);
998}
999
1000/**
1001 * nlmsg_new - Allocate a new netlink message
1002 * @payload: size of the message payload
1003 * @flags: the type of memory to allocate.
1004 *
1005 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
1006 * and a good default is needed.
1007 */
1008static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
1009{
1010 return alloc_skb(size: nlmsg_total_size(payload), priority: flags);
1011}
1012
1013/**
1014 * nlmsg_end - Finalize a netlink message
1015 * @skb: socket buffer the message is stored in
1016 * @nlh: netlink message header
1017 *
1018 * Corrects the netlink message header to include the appeneded
1019 * attributes. Only necessary if attributes have been added to
1020 * the message.
1021 */
1022static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
1023{
1024 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
1025}
1026
1027/**
1028 * nlmsg_get_pos - return current position in netlink message
1029 * @skb: socket buffer the message is stored in
1030 *
1031 * Returns a pointer to the current tail of the message.
1032 */
1033static inline void *nlmsg_get_pos(struct sk_buff *skb)
1034{
1035 return skb_tail_pointer(skb);
1036}
1037
1038/**
1039 * nlmsg_trim - Trim message to a mark
1040 * @skb: socket buffer the message is stored in
1041 * @mark: mark to trim to
1042 *
1043 * Trims the message to the provided mark.
1044 */
1045static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1046{
1047 if (mark) {
1048 WARN_ON((unsigned char *) mark < skb->data);
1049 skb_trim(skb, len: (unsigned char *) mark - skb->data);
1050 }
1051}
1052
1053/**
1054 * nlmsg_cancel - Cancel construction of a netlink message
1055 * @skb: socket buffer the message is stored in
1056 * @nlh: netlink message header
1057 *
1058 * Removes the complete netlink message including all
1059 * attributes from the socket buffer again.
1060 */
1061static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1062{
1063 nlmsg_trim(skb, mark: nlh);
1064}
1065
1066/**
1067 * nlmsg_free - free a netlink message
1068 * @skb: socket buffer of netlink message
1069 */
1070static inline void nlmsg_free(struct sk_buff *skb)
1071{
1072 kfree_skb(skb);
1073}
1074
1075/**
1076 * nlmsg_multicast - multicast a netlink message
1077 * @sk: netlink socket to spread messages to
1078 * @skb: netlink message as socket buffer
1079 * @portid: own netlink portid to avoid sending to yourself
1080 * @group: multicast group id
1081 * @flags: allocation flags
1082 */
1083static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1084 u32 portid, unsigned int group, gfp_t flags)
1085{
1086 int err;
1087
1088 NETLINK_CB(skb).dst_group = group;
1089
1090 err = netlink_broadcast(ssk: sk, skb, portid, group, allocation: flags);
1091 if (err > 0)
1092 err = 0;
1093
1094 return err;
1095}
1096
1097/**
1098 * nlmsg_unicast - unicast a netlink message
1099 * @sk: netlink socket to spread message to
1100 * @skb: netlink message as socket buffer
1101 * @portid: netlink portid of the destination socket
1102 */
1103static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1104{
1105 int err;
1106
1107 err = netlink_unicast(ssk: sk, skb, portid, MSG_DONTWAIT);
1108 if (err > 0)
1109 err = 0;
1110
1111 return err;
1112}
1113
1114/**
1115 * nlmsg_for_each_msg - iterate over a stream of messages
1116 * @pos: loop counter, set to current message
1117 * @head: head of message stream
1118 * @len: length of message stream
1119 * @rem: initialized to len, holds bytes currently remaining in stream
1120 */
1121#define nlmsg_for_each_msg(pos, head, len, rem) \
1122 for (pos = head, rem = len; \
1123 nlmsg_ok(pos, rem); \
1124 pos = nlmsg_next(pos, &(rem)))
1125
1126/**
1127 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1128 * @cb: netlink callback structure that stores the sequence number
1129 * @nlh: netlink message header to write the flag to
1130 *
1131 * This function checks if the sequence (generation) number changed during dump
1132 * and if it did, advertises it in the netlink message header.
1133 *
1134 * The correct way to use it is to set cb->seq to the generation counter when
1135 * all locks for dumping have been acquired, and then call this function for
1136 * each message that is generated.
1137 *
1138 * Note that due to initialisation concerns, 0 is an invalid sequence number
1139 * and must not be used by code that uses this functionality.
1140 */
1141static inline void
1142nl_dump_check_consistent(struct netlink_callback *cb,
1143 struct nlmsghdr *nlh)
1144{
1145 if (cb->prev_seq && cb->seq != cb->prev_seq)
1146 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1147 cb->prev_seq = cb->seq;
1148}
1149
1150/**************************************************************************
1151 * Netlink Attributes
1152 **************************************************************************/
1153
1154/**
1155 * nla_attr_size - length of attribute not including padding
1156 * @payload: length of payload
1157 */
1158static inline int nla_attr_size(int payload)
1159{
1160 return NLA_HDRLEN + payload;
1161}
1162
1163/**
1164 * nla_total_size - total length of attribute including padding
1165 * @payload: length of payload
1166 */
1167static inline int nla_total_size(int payload)
1168{
1169 return NLA_ALIGN(nla_attr_size(payload));
1170}
1171
1172/**
1173 * nla_padlen - length of padding at the tail of attribute
1174 * @payload: length of payload
1175 */
1176static inline int nla_padlen(int payload)
1177{
1178 return nla_total_size(payload) - nla_attr_size(payload);
1179}
1180
1181/**
1182 * nla_type - attribute type
1183 * @nla: netlink attribute
1184 */
1185static inline int nla_type(const struct nlattr *nla)
1186{
1187 return nla->nla_type & NLA_TYPE_MASK;
1188}
1189
1190/**
1191 * nla_data - head of payload
1192 * @nla: netlink attribute
1193 */
1194static inline void *nla_data(const struct nlattr *nla)
1195{
1196 return (char *) nla + NLA_HDRLEN;
1197}
1198
1199/**
1200 * nla_len - length of payload
1201 * @nla: netlink attribute
1202 */
1203static inline int nla_len(const struct nlattr *nla)
1204{
1205 return nla->nla_len - NLA_HDRLEN;
1206}
1207
1208/**
1209 * nla_ok - check if the netlink attribute fits into the remaining bytes
1210 * @nla: netlink attribute
1211 * @remaining: number of bytes remaining in attribute stream
1212 */
1213static inline int nla_ok(const struct nlattr *nla, int remaining)
1214{
1215 return remaining >= (int) sizeof(*nla) &&
1216 nla->nla_len >= sizeof(*nla) &&
1217 nla->nla_len <= remaining;
1218}
1219
1220/**
1221 * nla_next - next netlink attribute in attribute stream
1222 * @nla: netlink attribute
1223 * @remaining: number of bytes remaining in attribute stream
1224 *
1225 * Returns the next netlink attribute in the attribute stream and
1226 * decrements remaining by the size of the current attribute.
1227 */
1228static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1229{
1230 unsigned int totlen = NLA_ALIGN(nla->nla_len);
1231
1232 *remaining -= totlen;
1233 return (struct nlattr *) ((char *) nla + totlen);
1234}
1235
1236/**
1237 * nla_find_nested - find attribute in a set of nested attributes
1238 * @nla: attribute containing the nested attributes
1239 * @attrtype: type of attribute to look for
1240 *
1241 * Returns the first attribute which matches the specified type.
1242 */
1243static inline struct nlattr *
1244nla_find_nested(const struct nlattr *nla, int attrtype)
1245{
1246 return nla_find(head: nla_data(nla), len: nla_len(nla), attrtype);
1247}
1248
1249/**
1250 * nla_parse_nested - parse nested attributes
1251 * @tb: destination array with maxtype+1 elements
1252 * @maxtype: maximum attribute type to be expected
1253 * @nla: attribute containing the nested attributes
1254 * @policy: validation policy
1255 * @extack: extended ACK report struct
1256 *
1257 * See nla_parse()
1258 */
1259static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1260 const struct nlattr *nla,
1261 const struct nla_policy *policy,
1262 struct netlink_ext_ack *extack)
1263{
1264 if (!(nla->nla_type & NLA_F_NESTED)) {
1265 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1266 return -EINVAL;
1267 }
1268
1269 return __nla_parse(tb, maxtype, head: nla_data(nla), len: nla_len(nla), policy,
1270 NL_VALIDATE_STRICT, extack);
1271}
1272
1273/**
1274 * nla_parse_nested_deprecated - parse nested attributes
1275 * @tb: destination array with maxtype+1 elements
1276 * @maxtype: maximum attribute type to be expected
1277 * @nla: attribute containing the nested attributes
1278 * @policy: validation policy
1279 * @extack: extended ACK report struct
1280 *
1281 * See nla_parse_deprecated()
1282 */
1283static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1284 const struct nlattr *nla,
1285 const struct nla_policy *policy,
1286 struct netlink_ext_ack *extack)
1287{
1288 return __nla_parse(tb, maxtype, head: nla_data(nla), len: nla_len(nla), policy,
1289 validate: NL_VALIDATE_LIBERAL, extack);
1290}
1291
1292/**
1293 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1294 * @skb: socket buffer to add attribute to
1295 * @attrtype: attribute type
1296 * @value: numeric value
1297 */
1298static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1299{
1300 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
1301 u8 tmp = value;
1302
1303 return nla_put(skb, attrtype, attrlen: sizeof(u8), data: &tmp);
1304}
1305
1306/**
1307 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1308 * @skb: socket buffer to add attribute to
1309 * @attrtype: attribute type
1310 * @value: numeric value
1311 */
1312static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1313{
1314 u16 tmp = value;
1315
1316 return nla_put(skb, attrtype, attrlen: sizeof(u16), data: &tmp);
1317}
1318
1319/**
1320 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1321 * @skb: socket buffer to add attribute to
1322 * @attrtype: attribute type
1323 * @value: numeric value
1324 */
1325static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1326{
1327 __be16 tmp = value;
1328
1329 return nla_put(skb, attrtype, attrlen: sizeof(__be16), data: &tmp);
1330}
1331
1332/**
1333 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1334 * @skb: socket buffer to add attribute to
1335 * @attrtype: attribute type
1336 * @value: numeric value
1337 */
1338static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1339{
1340 __be16 tmp = value;
1341
1342 return nla_put_be16(skb, attrtype: attrtype | NLA_F_NET_BYTEORDER, value: tmp);
1343}
1344
1345/**
1346 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1347 * @skb: socket buffer to add attribute to
1348 * @attrtype: attribute type
1349 * @value: numeric value
1350 */
1351static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1352{
1353 __le16 tmp = value;
1354
1355 return nla_put(skb, attrtype, attrlen: sizeof(__le16), data: &tmp);
1356}
1357
1358/**
1359 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1360 * @skb: socket buffer to add attribute to
1361 * @attrtype: attribute type
1362 * @value: numeric value
1363 */
1364static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1365{
1366 u32 tmp = value;
1367
1368 return nla_put(skb, attrtype, attrlen: sizeof(u32), data: &tmp);
1369}
1370
1371/**
1372 * nla_put_uint - Add a variable-size unsigned int to a socket buffer
1373 * @skb: socket buffer to add attribute to
1374 * @attrtype: attribute type
1375 * @value: numeric value
1376 */
1377static inline int nla_put_uint(struct sk_buff *skb, int attrtype, u64 value)
1378{
1379 u64 tmp64 = value;
1380 u32 tmp32 = value;
1381
1382 if (tmp64 == tmp32)
1383 return nla_put_u32(skb, attrtype, value: tmp32);
1384 return nla_put(skb, attrtype, attrlen: sizeof(u64), data: &tmp64);
1385}
1386
1387/**
1388 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1389 * @skb: socket buffer to add attribute to
1390 * @attrtype: attribute type
1391 * @value: numeric value
1392 */
1393static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1394{
1395 __be32 tmp = value;
1396
1397 return nla_put(skb, attrtype, attrlen: sizeof(__be32), data: &tmp);
1398}
1399
1400/**
1401 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1402 * @skb: socket buffer to add attribute to
1403 * @attrtype: attribute type
1404 * @value: numeric value
1405 */
1406static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1407{
1408 __be32 tmp = value;
1409
1410 return nla_put_be32(skb, attrtype: attrtype | NLA_F_NET_BYTEORDER, value: tmp);
1411}
1412
1413/**
1414 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1415 * @skb: socket buffer to add attribute to
1416 * @attrtype: attribute type
1417 * @value: numeric value
1418 */
1419static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1420{
1421 __le32 tmp = value;
1422
1423 return nla_put(skb, attrtype, attrlen: sizeof(__le32), data: &tmp);
1424}
1425
1426/**
1427 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1428 * @skb: socket buffer to add attribute to
1429 * @attrtype: attribute type
1430 * @value: numeric value
1431 * @padattr: attribute type for the padding
1432 */
1433static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1434 u64 value, int padattr)
1435{
1436 u64 tmp = value;
1437
1438 return nla_put_64bit(skb, attrtype, attrlen: sizeof(u64), data: &tmp, padattr);
1439}
1440
1441/**
1442 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1443 * @skb: socket buffer to add attribute to
1444 * @attrtype: attribute type
1445 * @value: numeric value
1446 * @padattr: attribute type for the padding
1447 */
1448static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1449 int padattr)
1450{
1451 __be64 tmp = value;
1452
1453 return nla_put_64bit(skb, attrtype, attrlen: sizeof(__be64), data: &tmp, padattr);
1454}
1455
1456/**
1457 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1458 * @skb: socket buffer to add attribute to
1459 * @attrtype: attribute type
1460 * @value: numeric value
1461 * @padattr: attribute type for the padding
1462 */
1463static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1464 int padattr)
1465{
1466 __be64 tmp = value;
1467
1468 return nla_put_be64(skb, attrtype: attrtype | NLA_F_NET_BYTEORDER, value: tmp,
1469 padattr);
1470}
1471
1472/**
1473 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1474 * @skb: socket buffer to add attribute to
1475 * @attrtype: attribute type
1476 * @value: numeric value
1477 * @padattr: attribute type for the padding
1478 */
1479static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1480 int padattr)
1481{
1482 __le64 tmp = value;
1483
1484 return nla_put_64bit(skb, attrtype, attrlen: sizeof(__le64), data: &tmp, padattr);
1485}
1486
1487/**
1488 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1489 * @skb: socket buffer to add attribute to
1490 * @attrtype: attribute type
1491 * @value: numeric value
1492 */
1493static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1494{
1495 s8 tmp = value;
1496
1497 return nla_put(skb, attrtype, attrlen: sizeof(s8), data: &tmp);
1498}
1499
1500/**
1501 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1502 * @skb: socket buffer to add attribute to
1503 * @attrtype: attribute type
1504 * @value: numeric value
1505 */
1506static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1507{
1508 s16 tmp = value;
1509
1510 return nla_put(skb, attrtype, attrlen: sizeof(s16), data: &tmp);
1511}
1512
1513/**
1514 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1515 * @skb: socket buffer to add attribute to
1516 * @attrtype: attribute type
1517 * @value: numeric value
1518 */
1519static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1520{
1521 s32 tmp = value;
1522
1523 return nla_put(skb, attrtype, attrlen: sizeof(s32), data: &tmp);
1524}
1525
1526/**
1527 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1528 * @skb: socket buffer to add attribute to
1529 * @attrtype: attribute type
1530 * @value: numeric value
1531 * @padattr: attribute type for the padding
1532 */
1533static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1534 int padattr)
1535{
1536 s64 tmp = value;
1537
1538 return nla_put_64bit(skb, attrtype, attrlen: sizeof(s64), data: &tmp, padattr);
1539}
1540
1541/**
1542 * nla_put_sint - Add a variable-size signed int to a socket buffer
1543 * @skb: socket buffer to add attribute to
1544 * @attrtype: attribute type
1545 * @value: numeric value
1546 */
1547static inline int nla_put_sint(struct sk_buff *skb, int attrtype, s64 value)
1548{
1549 s64 tmp64 = value;
1550 s32 tmp32 = value;
1551
1552 if (tmp64 == tmp32)
1553 return nla_put_s32(skb, attrtype, value: tmp32);
1554 return nla_put(skb, attrtype, attrlen: sizeof(s64), data: &tmp64);
1555}
1556
1557/**
1558 * nla_put_string - Add a string netlink attribute to a socket buffer
1559 * @skb: socket buffer to add attribute to
1560 * @attrtype: attribute type
1561 * @str: NUL terminated string
1562 */
1563static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1564 const char *str)
1565{
1566 return nla_put(skb, attrtype, strlen(str) + 1, data: str);
1567}
1568
1569/**
1570 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1571 * @skb: socket buffer to add attribute to
1572 * @attrtype: attribute type
1573 */
1574static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1575{
1576 return nla_put(skb, attrtype, attrlen: 0, NULL);
1577}
1578
1579/**
1580 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1581 * @skb: socket buffer to add attribute to
1582 * @attrtype: attribute type
1583 * @njiffies: number of jiffies to convert to msecs
1584 * @padattr: attribute type for the padding
1585 */
1586static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1587 unsigned long njiffies, int padattr)
1588{
1589 u64 tmp = jiffies_to_msecs(j: njiffies);
1590
1591 return nla_put_64bit(skb, attrtype, attrlen: sizeof(u64), data: &tmp, padattr);
1592}
1593
1594/**
1595 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1596 * buffer
1597 * @skb: socket buffer to add attribute to
1598 * @attrtype: attribute type
1599 * @addr: IPv4 address
1600 */
1601static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1602 __be32 addr)
1603{
1604 __be32 tmp = addr;
1605
1606 return nla_put_be32(skb, attrtype, value: tmp);
1607}
1608
1609/**
1610 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1611 * buffer
1612 * @skb: socket buffer to add attribute to
1613 * @attrtype: attribute type
1614 * @addr: IPv6 address
1615 */
1616static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1617 const struct in6_addr *addr)
1618{
1619 return nla_put(skb, attrtype, attrlen: sizeof(*addr), data: addr);
1620}
1621
1622/**
1623 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1624 * @skb: socket buffer to add attribute to
1625 * @attrtype: attribute type
1626 * @value: value carrying bits
1627 * @selector: selector of valid bits
1628 */
1629static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1630 __u32 value, __u32 selector)
1631{
1632 struct nla_bitfield32 tmp = { value, selector, };
1633
1634 return nla_put(skb, attrtype, attrlen: sizeof(tmp), data: &tmp);
1635}
1636
1637/**
1638 * nla_get_u32 - return payload of u32 attribute
1639 * @nla: u32 netlink attribute
1640 */
1641static inline u32 nla_get_u32(const struct nlattr *nla)
1642{
1643 return *(u32 *) nla_data(nla);
1644}
1645
1646/**
1647 * nla_get_be32 - return payload of __be32 attribute
1648 * @nla: __be32 netlink attribute
1649 */
1650static inline __be32 nla_get_be32(const struct nlattr *nla)
1651{
1652 return *(__be32 *) nla_data(nla);
1653}
1654
1655/**
1656 * nla_get_le32 - return payload of __le32 attribute
1657 * @nla: __le32 netlink attribute
1658 */
1659static inline __le32 nla_get_le32(const struct nlattr *nla)
1660{
1661 return *(__le32 *) nla_data(nla);
1662}
1663
1664/**
1665 * nla_get_u16 - return payload of u16 attribute
1666 * @nla: u16 netlink attribute
1667 */
1668static inline u16 nla_get_u16(const struct nlattr *nla)
1669{
1670 return *(u16 *) nla_data(nla);
1671}
1672
1673/**
1674 * nla_get_be16 - return payload of __be16 attribute
1675 * @nla: __be16 netlink attribute
1676 */
1677static inline __be16 nla_get_be16(const struct nlattr *nla)
1678{
1679 return *(__be16 *) nla_data(nla);
1680}
1681
1682/**
1683 * nla_get_le16 - return payload of __le16 attribute
1684 * @nla: __le16 netlink attribute
1685 */
1686static inline __le16 nla_get_le16(const struct nlattr *nla)
1687{
1688 return *(__le16 *) nla_data(nla);
1689}
1690
1691/**
1692 * nla_get_u8 - return payload of u8 attribute
1693 * @nla: u8 netlink attribute
1694 */
1695static inline u8 nla_get_u8(const struct nlattr *nla)
1696{
1697 return *(u8 *) nla_data(nla);
1698}
1699
1700/**
1701 * nla_get_u64 - return payload of u64 attribute
1702 * @nla: u64 netlink attribute
1703 */
1704static inline u64 nla_get_u64(const struct nlattr *nla)
1705{
1706 u64 tmp;
1707
1708 nla_memcpy(dest: &tmp, src: nla, count: sizeof(tmp));
1709
1710 return tmp;
1711}
1712
1713/**
1714 * nla_get_uint - return payload of uint attribute
1715 * @nla: uint netlink attribute
1716 */
1717static inline u64 nla_get_uint(const struct nlattr *nla)
1718{
1719 if (nla_len(nla) == sizeof(u32))
1720 return nla_get_u32(nla);
1721 return nla_get_u64(nla);
1722}
1723
1724/**
1725 * nla_get_be64 - return payload of __be64 attribute
1726 * @nla: __be64 netlink attribute
1727 */
1728static inline __be64 nla_get_be64(const struct nlattr *nla)
1729{
1730 __be64 tmp;
1731
1732 nla_memcpy(dest: &tmp, src: nla, count: sizeof(tmp));
1733
1734 return tmp;
1735}
1736
1737/**
1738 * nla_get_le64 - return payload of __le64 attribute
1739 * @nla: __le64 netlink attribute
1740 */
1741static inline __le64 nla_get_le64(const struct nlattr *nla)
1742{
1743 return *(__le64 *) nla_data(nla);
1744}
1745
1746/**
1747 * nla_get_s32 - return payload of s32 attribute
1748 * @nla: s32 netlink attribute
1749 */
1750static inline s32 nla_get_s32(const struct nlattr *nla)
1751{
1752 return *(s32 *) nla_data(nla);
1753}
1754
1755/**
1756 * nla_get_s16 - return payload of s16 attribute
1757 * @nla: s16 netlink attribute
1758 */
1759static inline s16 nla_get_s16(const struct nlattr *nla)
1760{
1761 return *(s16 *) nla_data(nla);
1762}
1763
1764/**
1765 * nla_get_s8 - return payload of s8 attribute
1766 * @nla: s8 netlink attribute
1767 */
1768static inline s8 nla_get_s8(const struct nlattr *nla)
1769{
1770 return *(s8 *) nla_data(nla);
1771}
1772
1773/**
1774 * nla_get_s64 - return payload of s64 attribute
1775 * @nla: s64 netlink attribute
1776 */
1777static inline s64 nla_get_s64(const struct nlattr *nla)
1778{
1779 s64 tmp;
1780
1781 nla_memcpy(dest: &tmp, src: nla, count: sizeof(tmp));
1782
1783 return tmp;
1784}
1785
1786/**
1787 * nla_get_sint - return payload of uint attribute
1788 * @nla: uint netlink attribute
1789 */
1790static inline s64 nla_get_sint(const struct nlattr *nla)
1791{
1792 if (nla_len(nla) == sizeof(s32))
1793 return nla_get_s32(nla);
1794 return nla_get_s64(nla);
1795}
1796
1797/**
1798 * nla_get_flag - return payload of flag attribute
1799 * @nla: flag netlink attribute
1800 */
1801static inline int nla_get_flag(const struct nlattr *nla)
1802{
1803 return !!nla;
1804}
1805
1806/**
1807 * nla_get_msecs - return payload of msecs attribute
1808 * @nla: msecs netlink attribute
1809 *
1810 * Returns the number of milliseconds in jiffies.
1811 */
1812static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1813{
1814 u64 msecs = nla_get_u64(nla);
1815
1816 return msecs_to_jiffies(m: (unsigned long) msecs);
1817}
1818
1819/**
1820 * nla_get_in_addr - return payload of IPv4 address attribute
1821 * @nla: IPv4 address netlink attribute
1822 */
1823static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1824{
1825 return *(__be32 *) nla_data(nla);
1826}
1827
1828/**
1829 * nla_get_in6_addr - return payload of IPv6 address attribute
1830 * @nla: IPv6 address netlink attribute
1831 */
1832static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1833{
1834 struct in6_addr tmp;
1835
1836 nla_memcpy(dest: &tmp, src: nla, count: sizeof(tmp));
1837 return tmp;
1838}
1839
1840/**
1841 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1842 * @nla: nla_bitfield32 attribute
1843 */
1844static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1845{
1846 struct nla_bitfield32 tmp;
1847
1848 nla_memcpy(dest: &tmp, src: nla, count: sizeof(tmp));
1849 return tmp;
1850}
1851
1852/**
1853 * nla_memdup - duplicate attribute memory (kmemdup)
1854 * @src: netlink attribute to duplicate from
1855 * @gfp: GFP mask
1856 */
1857static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1858{
1859 return kmemdup(p: nla_data(nla: src), size: nla_len(nla: src), gfp);
1860}
1861
1862/**
1863 * nla_nest_start_noflag - Start a new level of nested attributes
1864 * @skb: socket buffer to add attributes to
1865 * @attrtype: attribute type of container
1866 *
1867 * This function exists for backward compatibility to use in APIs which never
1868 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1869 * nla_nest_start() which sets the flag.
1870 *
1871 * Returns the container attribute or NULL on error
1872 */
1873static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1874 int attrtype)
1875{
1876 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1877
1878 if (nla_put(skb, attrtype, attrlen: 0, NULL) < 0)
1879 return NULL;
1880
1881 return start;
1882}
1883
1884/**
1885 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1886 * @skb: socket buffer to add attributes to
1887 * @attrtype: attribute type of container
1888 *
1889 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1890 * flag. This is the preferred function to use in new code.
1891 *
1892 * Returns the container attribute or NULL on error
1893 */
1894static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1895{
1896 return nla_nest_start_noflag(skb, attrtype: attrtype | NLA_F_NESTED);
1897}
1898
1899/**
1900 * nla_nest_end - Finalize nesting of attributes
1901 * @skb: socket buffer the attributes are stored in
1902 * @start: container attribute
1903 *
1904 * Corrects the container attribute header to include the all
1905 * appeneded attributes.
1906 *
1907 * Returns the total data length of the skb.
1908 */
1909static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1910{
1911 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1912 return skb->len;
1913}
1914
1915/**
1916 * nla_nest_cancel - Cancel nesting of attributes
1917 * @skb: socket buffer the message is stored in
1918 * @start: container attribute
1919 *
1920 * Removes the container attribute and including all nested
1921 * attributes. Returns -EMSGSIZE
1922 */
1923static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1924{
1925 nlmsg_trim(skb, mark: start);
1926}
1927
1928/**
1929 * __nla_validate_nested - Validate a stream of nested attributes
1930 * @start: container attribute
1931 * @maxtype: maximum attribute type to be expected
1932 * @policy: validation policy
1933 * @validate: validation strictness
1934 * @extack: extended ACK report struct
1935 *
1936 * Validates all attributes in the nested attribute stream against the
1937 * specified policy. Attributes with a type exceeding maxtype will be
1938 * ignored. See documenation of struct nla_policy for more details.
1939 *
1940 * Returns 0 on success or a negative error code.
1941 */
1942static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1943 const struct nla_policy *policy,
1944 unsigned int validate,
1945 struct netlink_ext_ack *extack)
1946{
1947 return __nla_validate(head: nla_data(nla: start), len: nla_len(nla: start), maxtype, policy,
1948 validate, extack);
1949}
1950
1951static inline int
1952nla_validate_nested(const struct nlattr *start, int maxtype,
1953 const struct nla_policy *policy,
1954 struct netlink_ext_ack *extack)
1955{
1956 return __nla_validate_nested(start, maxtype, policy,
1957 NL_VALIDATE_STRICT, extack);
1958}
1959
1960static inline int
1961nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1962 const struct nla_policy *policy,
1963 struct netlink_ext_ack *extack)
1964{
1965 return __nla_validate_nested(start, maxtype, policy,
1966 validate: NL_VALIDATE_LIBERAL, extack);
1967}
1968
1969/**
1970 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1971 * @skb: socket buffer the message is stored in
1972 *
1973 * Return true if padding is needed to align the next attribute (nla_data()) to
1974 * a 64-bit aligned area.
1975 */
1976static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1977{
1978#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1979 /* The nlattr header is 4 bytes in size, that's why we test
1980 * if the skb->data _is_ aligned. A NOP attribute, plus
1981 * nlattr header for next attribute, will make nla_data()
1982 * 8-byte aligned.
1983 */
1984 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1985 return true;
1986#endif
1987 return false;
1988}
1989
1990/**
1991 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1992 * @skb: socket buffer the message is stored in
1993 * @padattr: attribute type for the padding
1994 *
1995 * Conditionally emit a padding netlink attribute in order to make
1996 * the next attribute we emit have a 64-bit aligned nla_data() area.
1997 * This will only be done in architectures which do not have
1998 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1999 *
2000 * Returns zero on success or a negative error code.
2001 */
2002static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
2003{
2004 if (nla_need_padding_for_64bit(skb) &&
2005 !nla_reserve(skb, attrtype: padattr, attrlen: 0))
2006 return -EMSGSIZE;
2007
2008 return 0;
2009}
2010
2011/**
2012 * nla_total_size_64bit - total length of attribute including padding
2013 * @payload: length of payload
2014 */
2015static inline int nla_total_size_64bit(int payload)
2016{
2017 return NLA_ALIGN(nla_attr_size(payload))
2018#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2019 + NLA_ALIGN(nla_attr_size(0))
2020#endif
2021 ;
2022}
2023
2024/**
2025 * nla_for_each_attr - iterate over a stream of attributes
2026 * @pos: loop counter, set to current attribute
2027 * @head: head of attribute stream
2028 * @len: length of attribute stream
2029 * @rem: initialized to len, holds bytes currently remaining in stream
2030 */
2031#define nla_for_each_attr(pos, head, len, rem) \
2032 for (pos = head, rem = len; \
2033 nla_ok(pos, rem); \
2034 pos = nla_next(pos, &(rem)))
2035
2036/**
2037 * nla_for_each_nested - iterate over nested attributes
2038 * @pos: loop counter, set to current attribute
2039 * @nla: attribute containing the nested attributes
2040 * @rem: initialized to len, holds bytes currently remaining in stream
2041 */
2042#define nla_for_each_nested(pos, nla, rem) \
2043 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
2044
2045/**
2046 * nla_is_last - Test if attribute is last in stream
2047 * @nla: attribute to test
2048 * @rem: bytes remaining in stream
2049 */
2050static inline bool nla_is_last(const struct nlattr *nla, int rem)
2051{
2052 return nla->nla_len == rem;
2053}
2054
2055void nla_get_range_unsigned(const struct nla_policy *pt,
2056 struct netlink_range_validation *range);
2057void nla_get_range_signed(const struct nla_policy *pt,
2058 struct netlink_range_validation_signed *range);
2059
2060struct netlink_policy_dump_state;
2061
2062int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
2063 const struct nla_policy *policy,
2064 unsigned int maxtype);
2065int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
2066 const struct nla_policy *policy,
2067 unsigned int maxtype);
2068bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
2069int netlink_policy_dump_write(struct sk_buff *skb,
2070 struct netlink_policy_dump_state *state);
2071int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
2072int netlink_policy_dump_write_attr(struct sk_buff *skb,
2073 const struct nla_policy *pt,
2074 int nestattr);
2075void netlink_policy_dump_free(struct netlink_policy_dump_state *state);
2076
2077#endif
2078

source code of linux/include/net/netlink.h