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_consume() free a netlink message (expected)
45 * nlmsg_free() free a netlink message (drop)
46 *
47 * Message Sending:
48 * nlmsg_multicast() multicast message to several groups
49 * nlmsg_unicast() unicast a message to a single socket
50 * nlmsg_notify() send notification message
51 *
52 * Message Length Calculations:
53 * nlmsg_msg_size(payload) length of message w/o padding
54 * nlmsg_total_size(payload) length of message w/ padding
55 * nlmsg_padlen(payload) length of padding at tail
56 *
57 * Message Payload Access:
58 * nlmsg_data(nlh) head of message payload
59 * nlmsg_len(nlh) length of message payload
60 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
61 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
62 *
63 * Message Parsing:
64 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
65 * nlmsg_next(nlh, remaining) get next netlink message
66 * nlmsg_parse() parse attributes of a message
67 * nlmsg_find_attr() find an attribute in a message
68 * nlmsg_for_each_msg() loop over all messages
69 * nlmsg_validate() validate netlink message incl. attrs
70 * nlmsg_for_each_attr() loop over all attributes
71 * nlmsg_for_each_attr_type() loop over all attributes with the
72 * given type
73 *
74 * Misc:
75 * nlmsg_report() report back to application?
76 *
77 * ------------------------------------------------------------------------
78 * Attributes Interface
79 * ------------------------------------------------------------------------
80 *
81 * Attribute Format:
82 * <------- nla_total_size(payload) ------->
83 * <---- nla_attr_size(payload) ----->
84 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
85 * | Header | Pad | Payload | Pad | Header
86 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
87 * <- nla_len(nla) -> ^
88 * nla_data(nla)----^ |
89 * nla_next(nla)-----------------------------'
90 *
91 * Data Structures:
92 * struct nlattr netlink attribute header
93 *
94 * Attribute Construction:
95 * nla_reserve(skb, type, len) reserve room for an attribute
96 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
97 * nla_put(skb, type, len, data) add attribute to skb
98 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
99 * nla_append(skb, len, data) append data to skb
100 *
101 * Attribute Construction for Basic Types:
102 * nla_put_u8(skb, type, value) add u8 attribute to skb
103 * nla_put_u16(skb, type, value) add u16 attribute to skb
104 * nla_put_u32(skb, type, value) add u32 attribute to skb
105 * nla_put_u64_64bit(skb, type,
106 * value, padattr) add u64 attribute to skb
107 * nla_put_s8(skb, type, value) add s8 attribute to skb
108 * nla_put_s16(skb, type, value) add s16 attribute to skb
109 * nla_put_s32(skb, type, value) add s32 attribute to skb
110 * nla_put_s64(skb, type, value,
111 * padattr) add s64 attribute to skb
112 * nla_put_string(skb, type, str) add string attribute to skb
113 * nla_put_flag(skb, type) add flag attribute to skb
114 * nla_put_msecs(skb, type, jiffies,
115 * padattr) add msecs attribute to skb
116 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb
117 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb
118 *
119 * Nested Attributes Construction:
120 * nla_nest_start(skb, type) start a nested attribute
121 * nla_nest_end(skb, nla) finalize a nested attribute
122 * nla_nest_cancel(skb, nla) cancel nested attribute construction
123 * nla_put_empty_nest(skb, type) create an empty nest
124 *
125 * Attribute Length Calculations:
126 * nla_attr_size(payload) length of attribute w/o padding
127 * nla_total_size(payload) length of attribute w/ padding
128 * nla_padlen(payload) length of padding
129 *
130 * Attribute Payload Access:
131 * nla_data(nla) head of attribute payload
132 * nla_len(nla) length of attribute payload
133 *
134 * Attribute Payload Access for Basic Types:
135 * nla_get_uint(nla) get payload for a uint attribute
136 * nla_get_sint(nla) get payload for a sint attribute
137 * nla_get_u8(nla) get payload for a u8 attribute
138 * nla_get_u16(nla) get payload for a u16 attribute
139 * nla_get_u32(nla) get payload for a u32 attribute
140 * nla_get_u64(nla) get payload for a u64 attribute
141 * nla_get_s8(nla) get payload for a s8 attribute
142 * nla_get_s16(nla) get payload for a s16 attribute
143 * nla_get_s32(nla) get payload for a s32 attribute
144 * nla_get_s64(nla) get payload for a s64 attribute
145 * nla_get_flag(nla) return 1 if flag is true
146 * nla_get_msecs(nla) get payload for a msecs attribute
147 *
148 * The same functions also exist with _default().
149 *
150 * Attribute Misc:
151 * nla_memcpy(dest, nla, count) copy attribute into memory
152 * nla_memcmp(nla, data, size) compare attribute with memory area
153 * nla_strscpy(dst, nla, size) copy attribute to a sized string
154 * nla_strcmp(nla, str) compare attribute with string
155 *
156 * Attribute Parsing:
157 * nla_ok(nla, remaining) does nla fit into remaining bytes?
158 * nla_next(nla, remaining) get next netlink attribute
159 * nla_validate() validate a stream of attributes
160 * nla_validate_nested() validate a stream of nested attributes
161 * nla_find() find attribute in stream of attributes
162 * nla_find_nested() find attribute in nested attributes
163 * nla_parse() parse and validate stream of attrs
164 * nla_parse_nested() parse nested attributes
165 * nla_for_each_attr() loop over all attributes
166 * nla_for_each_attr_type() loop over all attributes with the
167 * given type
168 * nla_for_each_nested() loop over the nested attributes
169 * nla_for_each_nested_type() loop over the nested attributes with
170 * the given type
171 *=========================================================================
172 */
173
174 /**
175 * Standard attribute types to specify validation policy
176 */
177enum {
178 NLA_UNSPEC,
179 NLA_U8,
180 NLA_U16,
181 NLA_U32,
182 NLA_U64,
183 NLA_STRING,
184 NLA_FLAG,
185 NLA_MSECS,
186 NLA_NESTED,
187 NLA_NESTED_ARRAY,
188 NLA_NUL_STRING,
189 NLA_BINARY,
190 NLA_S8,
191 NLA_S16,
192 NLA_S32,
193 NLA_S64,
194 NLA_BITFIELD32,
195 NLA_REJECT,
196 NLA_BE16,
197 NLA_BE32,
198 NLA_SINT,
199 NLA_UINT,
200 __NLA_TYPE_MAX,
201};
202
203#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
204
205struct netlink_range_validation {
206 u64 min, max;
207};
208
209struct netlink_range_validation_signed {
210 s64 min, max;
211};
212
213enum nla_policy_validation {
214 NLA_VALIDATE_NONE,
215 NLA_VALIDATE_RANGE,
216 NLA_VALIDATE_RANGE_WARN_TOO_LONG,
217 NLA_VALIDATE_MIN,
218 NLA_VALIDATE_MAX,
219 NLA_VALIDATE_MASK,
220 NLA_VALIDATE_RANGE_PTR,
221 NLA_VALIDATE_FUNCTION,
222};
223
224/**
225 * struct nla_policy - attribute validation policy
226 * @type: Type of attribute or NLA_UNSPEC
227 * @validation_type: type of attribute validation done in addition to
228 * type-specific validation (e.g. range, function call), see
229 * &enum nla_policy_validation
230 * @len: Type specific length of payload
231 *
232 * Policies are defined as arrays of this struct, the array must be
233 * accessible by attribute type up to the highest identifier to be expected.
234 *
235 * Meaning of `len' field:
236 * NLA_STRING Maximum length of string
237 * NLA_NUL_STRING Maximum length of string (excluding NUL)
238 * NLA_FLAG Unused
239 * NLA_BINARY Maximum length of attribute payload
240 * (but see also below with the validation type)
241 * NLA_NESTED,
242 * NLA_NESTED_ARRAY Length verification is done by checking len of
243 * nested header (or empty); len field is used if
244 * nested_policy is also used, for the max attr
245 * number in the nested policy.
246 * NLA_SINT, NLA_UINT,
247 * NLA_U8, NLA_U16,
248 * NLA_U32, NLA_U64,
249 * NLA_S8, NLA_S16,
250 * NLA_S32, NLA_S64,
251 * NLA_BE16, NLA_BE32,
252 * NLA_MSECS Leaving the length field zero will verify the
253 * given type fits, using it verifies minimum length
254 * just like "All other"
255 * NLA_BITFIELD32 Unused
256 * NLA_REJECT Unused
257 * All other Minimum length of attribute payload
258 *
259 * Meaning of validation union:
260 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and
261 * `bitfield32_valid' is the u32 value of valid flags
262 * NLA_REJECT This attribute is always rejected and `reject_message'
263 * may point to a string to report as the error instead
264 * of the generic one in extended ACK.
265 * NLA_NESTED `nested_policy' to a nested policy to validate, must
266 * also set `len' to the max attribute number. Use the
267 * provided NLA_POLICY_NESTED() macro.
268 * Note that nla_parse() will validate, but of course not
269 * parse, the nested sub-policies.
270 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate,
271 * must also set `len' to the max attribute number. Use
272 * the provided NLA_POLICY_NESTED_ARRAY() macro.
273 * The difference to NLA_NESTED is the structure:
274 * NLA_NESTED has the nested attributes directly inside
275 * while an array has the nested attributes at another
276 * level down and the attribute types directly in the
277 * nesting don't matter.
278 * NLA_UINT,
279 * NLA_U8,
280 * NLA_U16,
281 * NLA_U32,
282 * NLA_U64,
283 * NLA_BE16,
284 * NLA_BE32,
285 * NLA_SINT,
286 * NLA_S8,
287 * NLA_S16,
288 * NLA_S32,
289 * NLA_S64 The `min' and `max' fields are used depending on the
290 * validation_type field, if that is min/max/range then
291 * the min, max or both are used (respectively) to check
292 * the value of the integer attribute.
293 * Note that in the interest of code simplicity and
294 * struct size both limits are s16, so you cannot
295 * enforce a range that doesn't fall within the range
296 * of s16 - do that using the NLA_POLICY_FULL_RANGE()
297 * or NLA_POLICY_FULL_RANGE_SIGNED() macros instead.
298 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
299 * NLA_POLICY_RANGE() macros.
300 * NLA_UINT,
301 * NLA_U8,
302 * NLA_U16,
303 * NLA_U32,
304 * NLA_U64 If the validation_type field instead is set to
305 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
306 * to a struct netlink_range_validation that indicates
307 * the min/max values.
308 * Use NLA_POLICY_FULL_RANGE().
309 * NLA_SINT,
310 * NLA_S8,
311 * NLA_S16,
312 * NLA_S32,
313 * NLA_S64 If the validation_type field instead is set to
314 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
315 * pointer to a struct netlink_range_validation_signed
316 * that indicates the min/max values.
317 * Use NLA_POLICY_FULL_RANGE_SIGNED().
318 *
319 * NLA_BINARY If the validation type is like the ones for integers
320 * above, then the min/max length (not value like for
321 * integers) of the attribute is enforced.
322 *
323 * All other Unused - but note that it's a union
324 *
325 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
326 * NLA_U8, NLA_U16,
327 * NLA_U32, NLA_U64,
328 * NLA_S8, NLA_S16,
329 * NLA_S32, NLA_S64,
330 * NLA_MSECS,
331 * NLA_BINARY Validation function called for the attribute.
332 *
333 * All other Unused - but note that it's a union
334 *
335 * Example:
336 *
337 * static const u32 myvalidflags = 0xff231023;
338 *
339 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
340 * [ATTR_FOO] = { .type = NLA_U16 },
341 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
342 * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)),
343 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
344 * };
345 */
346struct nla_policy {
347 u8 type;
348 u8 validation_type;
349 u16 len;
350 union {
351 /**
352 * @strict_start_type: first attribute to validate strictly
353 *
354 * This entry is special, and used for the attribute at index 0
355 * only, and specifies special data about the policy, namely it
356 * specifies the "boundary type" where strict length validation
357 * starts for any attribute types >= this value, also, strict
358 * nesting validation starts here.
359 *
360 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
361 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to
362 * get the previous pure { .len = xyz } behaviour. The advantage
363 * of this is that types not specified in the policy will be
364 * rejected.
365 *
366 * For completely new families it should be set to 1 so that the
367 * validation is enforced for all attributes. For existing ones
368 * it should be set at least when new attributes are added to
369 * the enum used by the policy, and be set to the new value that
370 * was added to enforce strict validation from thereon.
371 */
372 u16 strict_start_type;
373
374 /* private: use NLA_POLICY_*() to set */
375 const u32 bitfield32_valid;
376 const u32 mask;
377 const char *reject_message;
378 const struct nla_policy *nested_policy;
379 const struct netlink_range_validation *range;
380 const struct netlink_range_validation_signed *range_signed;
381 struct {
382 s16 min, max;
383 };
384 int (*validate)(const struct nlattr *attr,
385 struct netlink_ext_ack *extack);
386 };
387};
388
389#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN)
390#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
391
392#define _NLA_POLICY_NESTED(maxattr, policy) \
393 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
394#define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
395 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
396#define NLA_POLICY_NESTED(policy) \
397 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
398#define NLA_POLICY_NESTED_ARRAY(policy) \
399 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
400#define NLA_POLICY_BITFIELD32(valid) \
401 { .type = NLA_BITFIELD32, .bitfield32_valid = valid }
402
403#define __NLA_IS_UINT_TYPE(tp) \
404 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || \
405 tp == NLA_U64 || tp == NLA_UINT || \
406 tp == NLA_BE16 || tp == NLA_BE32)
407#define __NLA_IS_SINT_TYPE(tp) \
408 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64 || \
409 tp == NLA_SINT)
410
411#define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
412#define NLA_ENSURE_UINT_TYPE(tp) \
413 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
414#define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \
415 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
416 tp == NLA_MSECS || \
417 tp == NLA_BINARY) + tp)
418#define NLA_ENSURE_SINT_TYPE(tp) \
419 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
420#define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \
421 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
422 __NLA_IS_SINT_TYPE(tp) || \
423 tp == NLA_MSECS || \
424 tp == NLA_BINARY) + tp)
425#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
426 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \
427 tp != NLA_REJECT && \
428 tp != NLA_NESTED && \
429 tp != NLA_NESTED_ARRAY) + tp)
430
431#define NLA_POLICY_RANGE(tp, _min, _max) { \
432 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
433 .validation_type = NLA_VALIDATE_RANGE, \
434 .min = _min, \
435 .max = _max \
436}
437
438#define NLA_POLICY_FULL_RANGE(tp, _range) { \
439 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \
440 .validation_type = NLA_VALIDATE_RANGE_PTR, \
441 .range = _range, \
442}
443
444#define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \
445 .type = NLA_ENSURE_SINT_TYPE(tp), \
446 .validation_type = NLA_VALIDATE_RANGE_PTR, \
447 .range_signed = _range, \
448}
449
450#define NLA_POLICY_MIN(tp, _min) { \
451 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
452 .validation_type = NLA_VALIDATE_MIN, \
453 .min = _min, \
454}
455
456#define NLA_POLICY_MAX(tp, _max) { \
457 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
458 .validation_type = NLA_VALIDATE_MAX, \
459 .max = _max, \
460}
461
462#define NLA_POLICY_MASK(tp, _mask) { \
463 .type = NLA_ENSURE_UINT_TYPE(tp), \
464 .validation_type = NLA_VALIDATE_MASK, \
465 .mask = _mask, \
466}
467
468#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \
469 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \
470 .validation_type = NLA_VALIDATE_FUNCTION, \
471 .validate = fn, \
472 .len = __VA_ARGS__ + 0, \
473}
474
475#define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
476#define NLA_POLICY_EXACT_LEN_WARN(_len) { \
477 .type = NLA_BINARY, \
478 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \
479 .min = _len, \
480 .max = _len \
481}
482#define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len)
483#define NLA_POLICY_MAX_LEN(_len) NLA_POLICY_MAX(NLA_BINARY, _len)
484
485/**
486 * struct nl_info - netlink source information
487 * @nlh: Netlink message header of original request
488 * @nl_net: Network namespace
489 * @portid: Netlink PORTID of requesting application
490 * @skip_notify: Skip netlink notifications to user space
491 * @skip_notify_kernel: Skip selected in-kernel notifications
492 */
493struct nl_info {
494 struct nlmsghdr *nlh;
495 struct net *nl_net;
496 u32 portid;
497 u8 skip_notify:1,
498 skip_notify_kernel:1;
499};
500
501/**
502 * enum netlink_validation - netlink message/attribute validation levels
503 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
504 * extra data at the end of the message, attributes being longer than
505 * they should be, or unknown attributes being present.
506 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
507 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
508 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
509 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
510 * This can safely be set by the kernel when the given policy has no
511 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
512 * are enforced going forward.
513 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
514 * U8, U16, U32 must have exact size, etc.)
515 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
516 * and unset for other policies.
517 */
518enum netlink_validation {
519 NL_VALIDATE_LIBERAL = 0,
520 NL_VALIDATE_TRAILING = BIT(0),
521 NL_VALIDATE_MAXTYPE = BIT(1),
522 NL_VALIDATE_UNSPEC = BIT(2),
523 NL_VALIDATE_STRICT_ATTRS = BIT(3),
524 NL_VALIDATE_NESTED = BIT(4),
525};
526
527#define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
528 NL_VALIDATE_MAXTYPE)
529#define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
530 NL_VALIDATE_MAXTYPE |\
531 NL_VALIDATE_UNSPEC |\
532 NL_VALIDATE_STRICT_ATTRS |\
533 NL_VALIDATE_NESTED)
534
535int netlink_rcv_skb(struct sk_buff *skb,
536 int (*cb)(struct sk_buff *, struct nlmsghdr *,
537 struct netlink_ext_ack *));
538int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
539 unsigned int group, int report, gfp_t flags);
540
541int __nla_validate(const struct nlattr *head, int len, int maxtype,
542 const struct nla_policy *policy, unsigned int validate,
543 struct netlink_ext_ack *extack);
544int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
545 int len, const struct nla_policy *policy, unsigned int validate,
546 struct netlink_ext_ack *extack);
547int nla_policy_len(const struct nla_policy *, int);
548struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
549ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
550char *nla_strdup(const struct nlattr *nla, gfp_t flags);
551int nla_memcpy(void *dest, const struct nlattr *src, int count);
552int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
553int nla_strcmp(const struct nlattr *nla, const char *str);
554struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
555struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
556 int attrlen, int padattr);
557void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
558struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
559struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
560 int attrlen, int padattr);
561void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
562void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
563 const void *data);
564void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
565 const void *data, int padattr);
566void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
567int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
568int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
569 const void *data, int padattr);
570int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
571int nla_append(struct sk_buff *skb, int attrlen, const void *data);
572
573/**************************************************************************
574 * Netlink Messages
575 **************************************************************************/
576
577/**
578 * nlmsg_msg_size - length of netlink message not including padding
579 * @payload: length of message payload
580 */
581static inline int nlmsg_msg_size(int payload)
582{
583 return NLMSG_HDRLEN + payload;
584}
585
586/**
587 * nlmsg_total_size - length of netlink message including padding
588 * @payload: length of message payload
589 */
590static inline int nlmsg_total_size(int payload)
591{
592 return NLMSG_ALIGN(nlmsg_msg_size(payload));
593}
594
595/**
596 * nlmsg_padlen - length of padding at the message's tail
597 * @payload: length of message payload
598 */
599static inline int nlmsg_padlen(int payload)
600{
601 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
602}
603
604/**
605 * nlmsg_data - head of message payload
606 * @nlh: netlink message header
607 */
608static inline void *nlmsg_data(const struct nlmsghdr *nlh)
609{
610 return (unsigned char *) nlh + NLMSG_HDRLEN;
611}
612
613/**
614 * nlmsg_len - length of message payload
615 * @nlh: netlink message header
616 */
617static inline int nlmsg_len(const struct nlmsghdr *nlh)
618{
619 return nlh->nlmsg_len - NLMSG_HDRLEN;
620}
621
622/**
623 * nlmsg_payload - message payload if the data fits in the len
624 * @nlh: netlink message header
625 * @len: struct length
626 *
627 * Returns: The netlink message payload/data if the length is sufficient,
628 * otherwise NULL.
629 */
630static inline void *nlmsg_payload(const struct nlmsghdr *nlh, size_t len)
631{
632 if (nlh->nlmsg_len < nlmsg_msg_size(payload: len))
633 return NULL;
634
635 return nlmsg_data(nlh);
636}
637
638/**
639 * nlmsg_attrdata - head of attributes data
640 * @nlh: netlink message header
641 * @hdrlen: length of family specific header
642 */
643static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
644 int hdrlen)
645{
646 unsigned char *data = nlmsg_data(nlh);
647 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
648}
649
650/**
651 * nlmsg_attrlen - length of attributes data
652 * @nlh: netlink message header
653 * @hdrlen: length of family specific header
654 */
655static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
656{
657 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
658}
659
660/**
661 * nlmsg_ok - check if the netlink message fits into the remaining bytes
662 * @nlh: netlink message header
663 * @remaining: number of bytes remaining in message stream
664 */
665static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
666{
667 return (remaining >= (int) sizeof(struct nlmsghdr) &&
668 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
669 nlh->nlmsg_len <= remaining);
670}
671
672/**
673 * nlmsg_next - next netlink message in message stream
674 * @nlh: netlink message header
675 * @remaining: number of bytes remaining in message stream
676 *
677 * Returns: the next netlink message in the message stream and
678 * decrements remaining by the size of the current message.
679 */
680static inline struct nlmsghdr *
681nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
682{
683 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
684
685 *remaining -= totlen;
686
687 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
688}
689
690/**
691 * nla_parse - Parse a stream of attributes into a tb buffer
692 * @tb: destination array with maxtype+1 elements
693 * @maxtype: maximum attribute type to be expected
694 * @head: head of attribute stream
695 * @len: length of attribute stream
696 * @policy: validation policy
697 * @extack: extended ACK pointer
698 *
699 * Parses a stream of attributes and stores a pointer to each attribute in
700 * the tb array accessible via the attribute type. Attributes with a type
701 * exceeding maxtype will be rejected, policy must be specified, attributes
702 * will be validated in the strictest way possible.
703 *
704 * Returns: 0 on success or a negative error code.
705 */
706static inline int nla_parse(struct nlattr **tb, int maxtype,
707 const struct nlattr *head, int len,
708 const struct nla_policy *policy,
709 struct netlink_ext_ack *extack)
710{
711 return __nla_parse(tb, maxtype, head, len, policy,
712 NL_VALIDATE_STRICT, extack);
713}
714
715/**
716 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
717 * @tb: destination array with maxtype+1 elements
718 * @maxtype: maximum attribute type to be expected
719 * @head: head of attribute stream
720 * @len: length of attribute stream
721 * @policy: validation policy
722 * @extack: extended ACK pointer
723 *
724 * Parses a stream of attributes and stores a pointer to each attribute in
725 * the tb array accessible via the attribute type. Attributes with a type
726 * exceeding maxtype will be ignored and attributes from the policy are not
727 * always strictly validated (only for new attributes).
728 *
729 * Returns: 0 on success or a negative error code.
730 */
731static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
732 const struct nlattr *head, int len,
733 const struct nla_policy *policy,
734 struct netlink_ext_ack *extack)
735{
736 return __nla_parse(tb, maxtype, head, len, policy,
737 validate: NL_VALIDATE_LIBERAL, extack);
738}
739
740/**
741 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
742 * @tb: destination array with maxtype+1 elements
743 * @maxtype: maximum attribute type to be expected
744 * @head: head of attribute stream
745 * @len: length of attribute stream
746 * @policy: validation policy
747 * @extack: extended ACK pointer
748 *
749 * Parses a stream of attributes and stores a pointer to each attribute in
750 * the tb array accessible via the attribute type. Attributes with a type
751 * exceeding maxtype will be rejected as well as trailing data, but the
752 * policy is not completely strictly validated (only for new attributes).
753 *
754 * Returns: 0 on success or a negative error code.
755 */
756static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
757 const struct nlattr *head,
758 int len,
759 const struct nla_policy *policy,
760 struct netlink_ext_ack *extack)
761{
762 return __nla_parse(tb, maxtype, head, len, policy,
763 NL_VALIDATE_DEPRECATED_STRICT, extack);
764}
765
766/**
767 * __nlmsg_parse - parse attributes of a netlink message
768 * @nlh: netlink message header
769 * @hdrlen: length of family specific header
770 * @tb: destination array with maxtype+1 elements
771 * @maxtype: maximum attribute type to be expected
772 * @policy: validation policy
773 * @validate: validation strictness
774 * @extack: extended ACK report struct
775 *
776 * See nla_parse()
777 */
778static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
779 struct nlattr *tb[], int maxtype,
780 const struct nla_policy *policy,
781 unsigned int validate,
782 struct netlink_ext_ack *extack)
783{
784 if (nlh->nlmsg_len < nlmsg_msg_size(payload: hdrlen)) {
785 NL_SET_ERR_MSG(extack, "Invalid header length");
786 return -EINVAL;
787 }
788
789 return __nla_parse(tb, maxtype, head: nlmsg_attrdata(nlh, hdrlen),
790 len: nlmsg_attrlen(nlh, hdrlen), policy, validate,
791 extack);
792}
793
794/**
795 * nlmsg_parse - parse attributes of a netlink message
796 * @nlh: netlink message header
797 * @hdrlen: length of family specific header
798 * @tb: destination array with maxtype+1 elements
799 * @maxtype: maximum attribute type to be expected
800 * @policy: validation policy
801 * @extack: extended ACK report struct
802 *
803 * See nla_parse()
804 */
805static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
806 struct nlattr *tb[], int maxtype,
807 const struct nla_policy *policy,
808 struct netlink_ext_ack *extack)
809{
810 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
811 NL_VALIDATE_STRICT, extack);
812}
813
814/**
815 * nlmsg_parse_deprecated - parse attributes of a netlink message
816 * @nlh: netlink message header
817 * @hdrlen: length of family specific header
818 * @tb: destination array with maxtype+1 elements
819 * @maxtype: maximum attribute type to be expected
820 * @policy: validation policy
821 * @extack: extended ACK report struct
822 *
823 * See nla_parse_deprecated()
824 */
825static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
826 struct nlattr *tb[], int maxtype,
827 const struct nla_policy *policy,
828 struct netlink_ext_ack *extack)
829{
830 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
831 validate: NL_VALIDATE_LIBERAL, extack);
832}
833
834/**
835 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
836 * @nlh: netlink message header
837 * @hdrlen: length of family specific header
838 * @tb: destination array with maxtype+1 elements
839 * @maxtype: maximum attribute type to be expected
840 * @policy: validation policy
841 * @extack: extended ACK report struct
842 *
843 * See nla_parse_deprecated_strict()
844 */
845static inline int
846nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
847 struct nlattr *tb[], int maxtype,
848 const struct nla_policy *policy,
849 struct netlink_ext_ack *extack)
850{
851 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
852 NL_VALIDATE_DEPRECATED_STRICT, extack);
853}
854
855/**
856 * nlmsg_find_attr - find a specific attribute in a netlink message
857 * @nlh: netlink message header
858 * @hdrlen: length of family specific header
859 * @attrtype: type of attribute to look for
860 *
861 * Returns: the first attribute which matches the specified type.
862 */
863static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
864 int hdrlen, int attrtype)
865{
866 return nla_find(head: nlmsg_attrdata(nlh, hdrlen),
867 len: nlmsg_attrlen(nlh, hdrlen), attrtype);
868}
869
870/**
871 * nla_validate_deprecated - Validate a stream of attributes
872 * @head: head of attribute stream
873 * @len: length of attribute stream
874 * @maxtype: maximum attribute type to be expected
875 * @policy: validation policy
876 * @extack: extended ACK report struct
877 *
878 * Validates all attributes in the specified attribute stream against the
879 * specified policy. Validation is done in liberal mode.
880 * See documentation of struct nla_policy for more details.
881 *
882 * Returns: 0 on success or a negative error code.
883 */
884static inline int nla_validate_deprecated(const struct nlattr *head, int len,
885 int maxtype,
886 const struct nla_policy *policy,
887 struct netlink_ext_ack *extack)
888{
889 return __nla_validate(head, len, maxtype, policy, validate: NL_VALIDATE_LIBERAL,
890 extack);
891}
892
893/**
894 * nla_validate - Validate a stream of attributes
895 * @head: head of attribute stream
896 * @len: length of attribute stream
897 * @maxtype: maximum attribute type to be expected
898 * @policy: validation policy
899 * @extack: extended ACK report struct
900 *
901 * Validates all attributes in the specified attribute stream against the
902 * specified policy. Validation is done in strict mode.
903 * See documentation of struct nla_policy for more details.
904 *
905 * Returns: 0 on success or a negative error code.
906 */
907static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
908 const struct nla_policy *policy,
909 struct netlink_ext_ack *extack)
910{
911 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
912 extack);
913}
914
915/**
916 * nlmsg_validate_deprecated - validate a netlink message including attributes
917 * @nlh: netlinket message header
918 * @hdrlen: length of family specific header
919 * @maxtype: maximum attribute type to be expected
920 * @policy: validation policy
921 * @extack: extended ACK report struct
922 */
923static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
924 int hdrlen, int maxtype,
925 const struct nla_policy *policy,
926 struct netlink_ext_ack *extack)
927{
928 if (nlh->nlmsg_len < nlmsg_msg_size(payload: hdrlen))
929 return -EINVAL;
930
931 return __nla_validate(head: nlmsg_attrdata(nlh, hdrlen),
932 len: nlmsg_attrlen(nlh, hdrlen), maxtype,
933 policy, validate: NL_VALIDATE_LIBERAL, extack);
934}
935
936
937
938/**
939 * nlmsg_report - need to report back to application?
940 * @nlh: netlink message header
941 *
942 * Returns: 1 if a report back to the application is requested.
943 */
944static inline int nlmsg_report(const struct nlmsghdr *nlh)
945{
946 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
947}
948
949/**
950 * nlmsg_seq - return the seq number of netlink message
951 * @nlh: netlink message header
952 *
953 * Returns: 0 if netlink message is NULL
954 */
955static inline u32 nlmsg_seq(const struct nlmsghdr *nlh)
956{
957 return nlh ? nlh->nlmsg_seq : 0;
958}
959
960/**
961 * nlmsg_for_each_attr - iterate over a stream of attributes
962 * @pos: loop counter, set to current attribute
963 * @nlh: netlink message header
964 * @hdrlen: length of family specific header
965 * @rem: initialized to len, holds bytes currently remaining in stream
966 */
967#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
968 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
969 nlmsg_attrlen(nlh, hdrlen), rem)
970
971/**
972 * nlmsg_for_each_attr_type - iterate over a stream of attributes
973 * @pos: loop counter, set to the current attribute
974 * @type: required attribute type for @pos
975 * @nlh: netlink message header
976 * @hdrlen: length of the family specific header
977 * @rem: initialized to len, holds bytes currently remaining in stream
978 */
979#define nlmsg_for_each_attr_type(pos, type, nlh, hdrlen, rem) \
980 nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
981 if (nla_type(pos) == type)
982
983/**
984 * nlmsg_put - Add a new netlink message to an skb
985 * @skb: socket buffer to store message in
986 * @portid: netlink PORTID of requesting application
987 * @seq: sequence number of message
988 * @type: message type
989 * @payload: length of message payload
990 * @flags: message flags
991 *
992 * Returns: NULL if the tailroom of the skb is insufficient to store
993 * the message header and payload.
994 */
995static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
996 int type, int payload, int flags)
997{
998 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
999 return NULL;
1000
1001 return __nlmsg_put(skb, portid, seq, type, len: payload, flags);
1002}
1003
1004/**
1005 * nlmsg_append - Add more data to a nlmsg in a skb
1006 * @skb: socket buffer to store message in
1007 * @size: length of message payload
1008 *
1009 * Append data to an existing nlmsg, used when constructing a message
1010 * with multiple fixed-format headers (which is rare).
1011 * Returns: NULL if the tailroom of the skb is insufficient to store
1012 * the extra payload.
1013 */
1014static inline void *nlmsg_append(struct sk_buff *skb, u32 size)
1015{
1016 if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size)))
1017 return NULL;
1018
1019 if (NLMSG_ALIGN(size) - size)
1020 memset(s: skb_tail_pointer(skb) + size, c: 0,
1021 NLMSG_ALIGN(size) - size);
1022 return __skb_put(skb, NLMSG_ALIGN(size));
1023}
1024
1025/**
1026 * nlmsg_put_answer - Add a new callback based netlink message to an skb
1027 * @skb: socket buffer to store message in
1028 * @cb: netlink callback
1029 * @type: message type
1030 * @payload: length of message payload
1031 * @flags: message flags
1032 *
1033 * Returns: NULL if the tailroom of the skb is insufficient to store
1034 * the message header and payload.
1035 */
1036static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
1037 struct netlink_callback *cb,
1038 int type, int payload,
1039 int flags)
1040{
1041 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, seq: cb->nlh->nlmsg_seq,
1042 type, payload, flags);
1043}
1044
1045/**
1046 * nlmsg_new - Allocate a new netlink message
1047 * @payload: size of the message payload
1048 * @flags: the type of memory to allocate.
1049 *
1050 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
1051 * and a good default is needed.
1052 */
1053static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
1054{
1055 return alloc_skb(size: nlmsg_total_size(payload), priority: flags);
1056}
1057
1058/**
1059 * nlmsg_new_large - Allocate a new netlink message with non-contiguous
1060 * physical memory
1061 * @payload: size of the message payload
1062 *
1063 * The allocated skb is unable to have frag page for shinfo->frags*,
1064 * as the NULL setting for skb->head in netlink_skb_destructor() will
1065 * bypass most of the handling in skb_release_data()
1066 */
1067static inline struct sk_buff *nlmsg_new_large(size_t payload)
1068{
1069 return netlink_alloc_large_skb(size: nlmsg_total_size(payload), broadcast: 0);
1070}
1071
1072/**
1073 * nlmsg_end - Finalize a netlink message
1074 * @skb: socket buffer the message is stored in
1075 * @nlh: netlink message header
1076 *
1077 * Corrects the netlink message header to include the appended
1078 * attributes. Only necessary if attributes have been added to
1079 * the message.
1080 */
1081static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
1082{
1083 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
1084}
1085
1086/**
1087 * nlmsg_get_pos - return current position in netlink message
1088 * @skb: socket buffer the message is stored in
1089 *
1090 * Returns: a pointer to the current tail of the message.
1091 */
1092static inline void *nlmsg_get_pos(struct sk_buff *skb)
1093{
1094 return skb_tail_pointer(skb);
1095}
1096
1097/**
1098 * nlmsg_trim - Trim message to a mark
1099 * @skb: socket buffer the message is stored in
1100 * @mark: mark to trim to
1101 *
1102 * Trims the message to the provided mark.
1103 */
1104static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1105{
1106 if (mark) {
1107 WARN_ON((unsigned char *) mark < skb->data);
1108 skb_trim(skb, len: (unsigned char *) mark - skb->data);
1109 }
1110}
1111
1112/**
1113 * nlmsg_cancel - Cancel construction of a netlink message
1114 * @skb: socket buffer the message is stored in
1115 * @nlh: netlink message header
1116 *
1117 * Removes the complete netlink message including all
1118 * attributes from the socket buffer again.
1119 */
1120static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1121{
1122 nlmsg_trim(skb, mark: nlh);
1123}
1124
1125/**
1126 * nlmsg_free - drop a netlink message
1127 * @skb: socket buffer of netlink message
1128 */
1129static inline void nlmsg_free(struct sk_buff *skb)
1130{
1131 kfree_skb(skb);
1132}
1133
1134/**
1135 * nlmsg_consume - free a netlink message
1136 * @skb: socket buffer of netlink message
1137 */
1138static inline void nlmsg_consume(struct sk_buff *skb)
1139{
1140 consume_skb(skb);
1141}
1142
1143/**
1144 * nlmsg_multicast_filtered - multicast a netlink message with filter function
1145 * @sk: netlink socket to spread messages to
1146 * @skb: netlink message as socket buffer
1147 * @portid: own netlink portid to avoid sending to yourself
1148 * @group: multicast group id
1149 * @flags: allocation flags
1150 * @filter: filter function
1151 * @filter_data: filter function private data
1152 *
1153 * Return: 0 on success, negative error code for failure.
1154 */
1155static inline int nlmsg_multicast_filtered(struct sock *sk, struct sk_buff *skb,
1156 u32 portid, unsigned int group,
1157 gfp_t flags,
1158 netlink_filter_fn filter,
1159 void *filter_data)
1160{
1161 int err;
1162
1163 NETLINK_CB(skb).dst_group = group;
1164
1165 err = netlink_broadcast_filtered(ssk: sk, skb, portid, group, allocation: flags,
1166 filter, filter_data);
1167 if (err > 0)
1168 err = 0;
1169
1170 return err;
1171}
1172
1173/**
1174 * nlmsg_multicast - multicast a netlink message
1175 * @sk: netlink socket to spread messages to
1176 * @skb: netlink message as socket buffer
1177 * @portid: own netlink portid to avoid sending to yourself
1178 * @group: multicast group id
1179 * @flags: allocation flags
1180 */
1181static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1182 u32 portid, unsigned int group, gfp_t flags)
1183{
1184 return nlmsg_multicast_filtered(sk, skb, portid, group, flags,
1185 NULL, NULL);
1186}
1187
1188/**
1189 * nlmsg_unicast - unicast a netlink message
1190 * @sk: netlink socket to spread message to
1191 * @skb: netlink message as socket buffer
1192 * @portid: netlink portid of the destination socket
1193 */
1194static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1195{
1196 int err;
1197
1198 err = netlink_unicast(ssk: sk, skb, portid, MSG_DONTWAIT);
1199 if (err > 0)
1200 err = 0;
1201
1202 return err;
1203}
1204
1205/**
1206 * nlmsg_for_each_msg - iterate over a stream of messages
1207 * @pos: loop counter, set to current message
1208 * @head: head of message stream
1209 * @len: length of message stream
1210 * @rem: initialized to len, holds bytes currently remaining in stream
1211 */
1212#define nlmsg_for_each_msg(pos, head, len, rem) \
1213 for (pos = head, rem = len; \
1214 nlmsg_ok(pos, rem); \
1215 pos = nlmsg_next(pos, &(rem)))
1216
1217/**
1218 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1219 * @cb: netlink callback structure that stores the sequence number
1220 * @nlh: netlink message header to write the flag to
1221 *
1222 * This function checks if the sequence (generation) number changed during dump
1223 * and if it did, advertises it in the netlink message header.
1224 *
1225 * The correct way to use it is to set cb->seq to the generation counter when
1226 * all locks for dumping have been acquired, and then call this function for
1227 * each message that is generated.
1228 *
1229 * Note that due to initialisation concerns, 0 is an invalid sequence number
1230 * and must not be used by code that uses this functionality.
1231 */
1232static inline void
1233nl_dump_check_consistent(struct netlink_callback *cb,
1234 struct nlmsghdr *nlh)
1235{
1236 if (cb->prev_seq && cb->seq != cb->prev_seq)
1237 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1238 cb->prev_seq = cb->seq;
1239}
1240
1241/**************************************************************************
1242 * Netlink Attributes
1243 **************************************************************************/
1244
1245/**
1246 * nla_attr_size - length of attribute not including padding
1247 * @payload: length of payload
1248 */
1249static inline int nla_attr_size(int payload)
1250{
1251 return NLA_HDRLEN + payload;
1252}
1253
1254/**
1255 * nla_total_size - total length of attribute including padding
1256 * @payload: length of payload
1257 */
1258static inline int nla_total_size(int payload)
1259{
1260 return NLA_ALIGN(nla_attr_size(payload));
1261}
1262
1263/**
1264 * nla_padlen - length of padding at the tail of attribute
1265 * @payload: length of payload
1266 */
1267static inline int nla_padlen(int payload)
1268{
1269 return nla_total_size(payload) - nla_attr_size(payload);
1270}
1271
1272/**
1273 * nla_type - attribute type
1274 * @nla: netlink attribute
1275 */
1276static inline int nla_type(const struct nlattr *nla)
1277{
1278 return nla->nla_type & NLA_TYPE_MASK;
1279}
1280
1281/**
1282 * nla_data - head of payload
1283 * @nla: netlink attribute
1284 */
1285static inline void *nla_data(const struct nlattr *nla)
1286{
1287 return (char *) nla + NLA_HDRLEN;
1288}
1289
1290/**
1291 * nla_len - length of payload
1292 * @nla: netlink attribute
1293 */
1294static inline u16 nla_len(const struct nlattr *nla)
1295{
1296 return nla->nla_len - NLA_HDRLEN;
1297}
1298
1299/**
1300 * nla_ok - check if the netlink attribute fits into the remaining bytes
1301 * @nla: netlink attribute
1302 * @remaining: number of bytes remaining in attribute stream
1303 */
1304static inline int nla_ok(const struct nlattr *nla, int remaining)
1305{
1306 return remaining >= (int) sizeof(*nla) &&
1307 nla->nla_len >= sizeof(*nla) &&
1308 nla->nla_len <= remaining;
1309}
1310
1311/**
1312 * nla_next - next netlink attribute in attribute stream
1313 * @nla: netlink attribute
1314 * @remaining: number of bytes remaining in attribute stream
1315 *
1316 * Returns: the next netlink attribute in the attribute stream and
1317 * decrements remaining by the size of the current attribute.
1318 */
1319static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1320{
1321 unsigned int totlen = NLA_ALIGN(nla->nla_len);
1322
1323 *remaining -= totlen;
1324 return (struct nlattr *) ((char *) nla + totlen);
1325}
1326
1327/**
1328 * nla_find_nested - find attribute in a set of nested attributes
1329 * @nla: attribute containing the nested attributes
1330 * @attrtype: type of attribute to look for
1331 *
1332 * Returns: the first attribute which matches the specified type.
1333 */
1334static inline struct nlattr *
1335nla_find_nested(const struct nlattr *nla, int attrtype)
1336{
1337 return nla_find(head: nla_data(nla), len: nla_len(nla), attrtype);
1338}
1339
1340/**
1341 * nla_parse_nested - parse nested attributes
1342 * @tb: destination array with maxtype+1 elements
1343 * @maxtype: maximum attribute type to be expected
1344 * @nla: attribute containing the nested attributes
1345 * @policy: validation policy
1346 * @extack: extended ACK report struct
1347 *
1348 * See nla_parse()
1349 */
1350static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1351 const struct nlattr *nla,
1352 const struct nla_policy *policy,
1353 struct netlink_ext_ack *extack)
1354{
1355 if (!(nla->nla_type & NLA_F_NESTED)) {
1356 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1357 return -EINVAL;
1358 }
1359
1360 return __nla_parse(tb, maxtype, head: nla_data(nla), len: nla_len(nla), policy,
1361 NL_VALIDATE_STRICT, extack);
1362}
1363
1364/**
1365 * nla_parse_nested_deprecated - parse nested attributes
1366 * @tb: destination array with maxtype+1 elements
1367 * @maxtype: maximum attribute type to be expected
1368 * @nla: attribute containing the nested attributes
1369 * @policy: validation policy
1370 * @extack: extended ACK report struct
1371 *
1372 * See nla_parse_deprecated()
1373 */
1374static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1375 const struct nlattr *nla,
1376 const struct nla_policy *policy,
1377 struct netlink_ext_ack *extack)
1378{
1379 return __nla_parse(tb, maxtype, head: nla_data(nla), len: nla_len(nla), policy,
1380 validate: NL_VALIDATE_LIBERAL, extack);
1381}
1382
1383/**
1384 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1385 * @skb: socket buffer to add attribute to
1386 * @attrtype: attribute type
1387 * @value: numeric value
1388 */
1389static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1390{
1391 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
1392 u8 tmp = value;
1393
1394 return nla_put(skb, attrtype, attrlen: sizeof(u8), data: &tmp);
1395}
1396
1397/**
1398 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1399 * @skb: socket buffer to add attribute to
1400 * @attrtype: attribute type
1401 * @value: numeric value
1402 */
1403static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1404{
1405 u16 tmp = value;
1406
1407 return nla_put(skb, attrtype, attrlen: sizeof(u16), data: &tmp);
1408}
1409
1410/**
1411 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1412 * @skb: socket buffer to add attribute to
1413 * @attrtype: attribute type
1414 * @value: numeric value
1415 */
1416static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1417{
1418 __be16 tmp = value;
1419
1420 return nla_put(skb, attrtype, attrlen: sizeof(__be16), data: &tmp);
1421}
1422
1423/**
1424 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1425 * @skb: socket buffer to add attribute to
1426 * @attrtype: attribute type
1427 * @value: numeric value
1428 */
1429static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1430{
1431 __be16 tmp = value;
1432
1433 return nla_put_be16(skb, attrtype: attrtype | NLA_F_NET_BYTEORDER, value: tmp);
1434}
1435
1436/**
1437 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1438 * @skb: socket buffer to add attribute to
1439 * @attrtype: attribute type
1440 * @value: numeric value
1441 */
1442static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1443{
1444 __le16 tmp = value;
1445
1446 return nla_put(skb, attrtype, attrlen: sizeof(__le16), data: &tmp);
1447}
1448
1449/**
1450 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1451 * @skb: socket buffer to add attribute to
1452 * @attrtype: attribute type
1453 * @value: numeric value
1454 */
1455static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1456{
1457 u32 tmp = value;
1458
1459 return nla_put(skb, attrtype, attrlen: sizeof(u32), data: &tmp);
1460}
1461
1462/**
1463 * nla_put_uint - Add a variable-size unsigned int to a socket buffer
1464 * @skb: socket buffer to add attribute to
1465 * @attrtype: attribute type
1466 * @value: numeric value
1467 */
1468static inline int nla_put_uint(struct sk_buff *skb, int attrtype, u64 value)
1469{
1470 u64 tmp64 = value;
1471 u32 tmp32 = value;
1472
1473 if (tmp64 == tmp32)
1474 return nla_put_u32(skb, attrtype, value: tmp32);
1475 return nla_put(skb, attrtype, attrlen: sizeof(u64), data: &tmp64);
1476}
1477
1478/**
1479 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1480 * @skb: socket buffer to add attribute to
1481 * @attrtype: attribute type
1482 * @value: numeric value
1483 */
1484static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1485{
1486 __be32 tmp = value;
1487
1488 return nla_put(skb, attrtype, attrlen: sizeof(__be32), data: &tmp);
1489}
1490
1491/**
1492 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1493 * @skb: socket buffer to add attribute to
1494 * @attrtype: attribute type
1495 * @value: numeric value
1496 */
1497static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1498{
1499 __be32 tmp = value;
1500
1501 return nla_put_be32(skb, attrtype: attrtype | NLA_F_NET_BYTEORDER, value: tmp);
1502}
1503
1504/**
1505 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1506 * @skb: socket buffer to add attribute to
1507 * @attrtype: attribute type
1508 * @value: numeric value
1509 */
1510static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1511{
1512 __le32 tmp = value;
1513
1514 return nla_put(skb, attrtype, attrlen: sizeof(__le32), data: &tmp);
1515}
1516
1517/**
1518 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1519 * @skb: socket buffer to add attribute to
1520 * @attrtype: attribute type
1521 * @value: numeric value
1522 * @padattr: attribute type for the padding
1523 */
1524static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1525 u64 value, int padattr)
1526{
1527 u64 tmp = value;
1528
1529 return nla_put_64bit(skb, attrtype, attrlen: sizeof(u64), data: &tmp, padattr);
1530}
1531
1532/**
1533 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1534 * @skb: socket buffer to add attribute to
1535 * @attrtype: attribute type
1536 * @value: numeric value
1537 * @padattr: attribute type for the padding
1538 */
1539static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1540 int padattr)
1541{
1542 __be64 tmp = value;
1543
1544 return nla_put_64bit(skb, attrtype, attrlen: sizeof(__be64), data: &tmp, padattr);
1545}
1546
1547/**
1548 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1549 * @skb: socket buffer to add attribute to
1550 * @attrtype: attribute type
1551 * @value: numeric value
1552 * @padattr: attribute type for the padding
1553 */
1554static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1555 int padattr)
1556{
1557 __be64 tmp = value;
1558
1559 return nla_put_be64(skb, attrtype: attrtype | NLA_F_NET_BYTEORDER, value: tmp,
1560 padattr);
1561}
1562
1563/**
1564 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1565 * @skb: socket buffer to add attribute to
1566 * @attrtype: attribute type
1567 * @value: numeric value
1568 * @padattr: attribute type for the padding
1569 */
1570static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1571 int padattr)
1572{
1573 __le64 tmp = value;
1574
1575 return nla_put_64bit(skb, attrtype, attrlen: sizeof(__le64), data: &tmp, padattr);
1576}
1577
1578/**
1579 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1580 * @skb: socket buffer to add attribute to
1581 * @attrtype: attribute type
1582 * @value: numeric value
1583 */
1584static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1585{
1586 s8 tmp = value;
1587
1588 return nla_put(skb, attrtype, attrlen: sizeof(s8), data: &tmp);
1589}
1590
1591/**
1592 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1593 * @skb: socket buffer to add attribute to
1594 * @attrtype: attribute type
1595 * @value: numeric value
1596 */
1597static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1598{
1599 s16 tmp = value;
1600
1601 return nla_put(skb, attrtype, attrlen: sizeof(s16), data: &tmp);
1602}
1603
1604/**
1605 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1606 * @skb: socket buffer to add attribute to
1607 * @attrtype: attribute type
1608 * @value: numeric value
1609 */
1610static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1611{
1612 s32 tmp = value;
1613
1614 return nla_put(skb, attrtype, attrlen: sizeof(s32), data: &tmp);
1615}
1616
1617/**
1618 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1619 * @skb: socket buffer to add attribute to
1620 * @attrtype: attribute type
1621 * @value: numeric value
1622 * @padattr: attribute type for the padding
1623 */
1624static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1625 int padattr)
1626{
1627 s64 tmp = value;
1628
1629 return nla_put_64bit(skb, attrtype, attrlen: sizeof(s64), data: &tmp, padattr);
1630}
1631
1632/**
1633 * nla_put_sint - Add a variable-size signed int to a socket buffer
1634 * @skb: socket buffer to add attribute to
1635 * @attrtype: attribute type
1636 * @value: numeric value
1637 */
1638static inline int nla_put_sint(struct sk_buff *skb, int attrtype, s64 value)
1639{
1640 s64 tmp64 = value;
1641 s32 tmp32 = value;
1642
1643 if (tmp64 == tmp32)
1644 return nla_put_s32(skb, attrtype, value: tmp32);
1645 return nla_put(skb, attrtype, attrlen: sizeof(s64), data: &tmp64);
1646}
1647
1648/**
1649 * nla_put_string - Add a string netlink attribute to a socket buffer
1650 * @skb: socket buffer to add attribute to
1651 * @attrtype: attribute type
1652 * @str: NUL terminated string
1653 */
1654static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1655 const char *str)
1656{
1657 return nla_put(skb, attrtype, attrlen: strlen(str) + 1, data: str);
1658}
1659
1660/**
1661 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1662 * @skb: socket buffer to add attribute to
1663 * @attrtype: attribute type
1664 */
1665static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1666{
1667 return nla_put(skb, attrtype, attrlen: 0, NULL);
1668}
1669
1670/**
1671 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1672 * @skb: socket buffer to add attribute to
1673 * @attrtype: attribute type
1674 * @njiffies: number of jiffies to convert to msecs
1675 * @padattr: attribute type for the padding
1676 */
1677static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1678 unsigned long njiffies, int padattr)
1679{
1680 u64 tmp = jiffies_to_msecs(j: njiffies);
1681
1682 return nla_put_64bit(skb, attrtype, attrlen: sizeof(u64), data: &tmp, padattr);
1683}
1684
1685/**
1686 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1687 * buffer
1688 * @skb: socket buffer to add attribute to
1689 * @attrtype: attribute type
1690 * @addr: IPv4 address
1691 */
1692static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1693 __be32 addr)
1694{
1695 __be32 tmp = addr;
1696
1697 return nla_put_be32(skb, attrtype, value: tmp);
1698}
1699
1700/**
1701 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1702 * buffer
1703 * @skb: socket buffer to add attribute to
1704 * @attrtype: attribute type
1705 * @addr: IPv6 address
1706 */
1707static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1708 const struct in6_addr *addr)
1709{
1710 return nla_put(skb, attrtype, attrlen: sizeof(*addr), data: addr);
1711}
1712
1713/**
1714 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1715 * @skb: socket buffer to add attribute to
1716 * @attrtype: attribute type
1717 * @value: value carrying bits
1718 * @selector: selector of valid bits
1719 */
1720static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1721 __u32 value, __u32 selector)
1722{
1723 struct nla_bitfield32 tmp = { value, selector, };
1724
1725 return nla_put(skb, attrtype, attrlen: sizeof(tmp), data: &tmp);
1726}
1727
1728/**
1729 * nla_get_u32 - return payload of u32 attribute
1730 * @nla: u32 netlink attribute
1731 */
1732static inline u32 nla_get_u32(const struct nlattr *nla)
1733{
1734 return *(u32 *) nla_data(nla);
1735}
1736
1737/**
1738 * nla_get_u32_default - return payload of u32 attribute or default
1739 * @nla: u32 netlink attribute, may be %NULL
1740 * @defvalue: default value to use if @nla is %NULL
1741 *
1742 * Return: the value of the attribute, or the default value if not present
1743 */
1744static inline u32 nla_get_u32_default(const struct nlattr *nla, u32 defvalue)
1745{
1746 if (!nla)
1747 return defvalue;
1748 return nla_get_u32(nla);
1749}
1750
1751/**
1752 * nla_get_be32 - return payload of __be32 attribute
1753 * @nla: __be32 netlink attribute
1754 */
1755static inline __be32 nla_get_be32(const struct nlattr *nla)
1756{
1757 return *(__be32 *) nla_data(nla);
1758}
1759
1760/**
1761 * nla_get_be32_default - return payload of be32 attribute or default
1762 * @nla: __be32 netlink attribute, may be %NULL
1763 * @defvalue: default value to use if @nla is %NULL
1764 *
1765 * Return: the value of the attribute, or the default value if not present
1766 */
1767static inline __be32 nla_get_be32_default(const struct nlattr *nla,
1768 __be32 defvalue)
1769{
1770 if (!nla)
1771 return defvalue;
1772 return nla_get_be32(nla);
1773}
1774
1775/**
1776 * nla_get_le32 - return payload of __le32 attribute
1777 * @nla: __le32 netlink attribute
1778 */
1779static inline __le32 nla_get_le32(const struct nlattr *nla)
1780{
1781 return *(__le32 *) nla_data(nla);
1782}
1783
1784/**
1785 * nla_get_le32_default - return payload of le32 attribute or default
1786 * @nla: __le32 netlink attribute, may be %NULL
1787 * @defvalue: default value to use if @nla is %NULL
1788 *
1789 * Return: the value of the attribute, or the default value if not present
1790 */
1791static inline __le32 nla_get_le32_default(const struct nlattr *nla,
1792 __le32 defvalue)
1793{
1794 if (!nla)
1795 return defvalue;
1796 return nla_get_le32(nla);
1797}
1798
1799/**
1800 * nla_get_u16 - return payload of u16 attribute
1801 * @nla: u16 netlink attribute
1802 */
1803static inline u16 nla_get_u16(const struct nlattr *nla)
1804{
1805 return *(u16 *) nla_data(nla);
1806}
1807
1808/**
1809 * nla_get_u16_default - return payload of u16 attribute or default
1810 * @nla: u16 netlink attribute, may be %NULL
1811 * @defvalue: default value to use if @nla is %NULL
1812 *
1813 * Return: the value of the attribute, or the default value if not present
1814 */
1815static inline u16 nla_get_u16_default(const struct nlattr *nla, u16 defvalue)
1816{
1817 if (!nla)
1818 return defvalue;
1819 return nla_get_u16(nla);
1820}
1821
1822/**
1823 * nla_get_be16 - return payload of __be16 attribute
1824 * @nla: __be16 netlink attribute
1825 */
1826static inline __be16 nla_get_be16(const struct nlattr *nla)
1827{
1828 return *(__be16 *) nla_data(nla);
1829}
1830
1831/**
1832 * nla_get_be16_default - return payload of be16 attribute or default
1833 * @nla: __be16 netlink attribute, may be %NULL
1834 * @defvalue: default value to use if @nla is %NULL
1835 *
1836 * Return: the value of the attribute, or the default value if not present
1837 */
1838static inline __be16 nla_get_be16_default(const struct nlattr *nla,
1839 __be16 defvalue)
1840{
1841 if (!nla)
1842 return defvalue;
1843 return nla_get_be16(nla);
1844}
1845
1846/**
1847 * nla_get_le16 - return payload of __le16 attribute
1848 * @nla: __le16 netlink attribute
1849 */
1850static inline __le16 nla_get_le16(const struct nlattr *nla)
1851{
1852 return *(__le16 *) nla_data(nla);
1853}
1854
1855/**
1856 * nla_get_le16_default - return payload of le16 attribute or default
1857 * @nla: __le16 netlink attribute, may be %NULL
1858 * @defvalue: default value to use if @nla is %NULL
1859 *
1860 * Return: the value of the attribute, or the default value if not present
1861 */
1862static inline __le16 nla_get_le16_default(const struct nlattr *nla,
1863 __le16 defvalue)
1864{
1865 if (!nla)
1866 return defvalue;
1867 return nla_get_le16(nla);
1868}
1869
1870/**
1871 * nla_get_u8 - return payload of u8 attribute
1872 * @nla: u8 netlink attribute
1873 */
1874static inline u8 nla_get_u8(const struct nlattr *nla)
1875{
1876 return *(u8 *) nla_data(nla);
1877}
1878
1879/**
1880 * nla_get_u8_default - return payload of u8 attribute or default
1881 * @nla: u8 netlink attribute, may be %NULL
1882 * @defvalue: default value to use if @nla is %NULL
1883 *
1884 * Return: the value of the attribute, or the default value if not present
1885 */
1886static inline u8 nla_get_u8_default(const struct nlattr *nla, u8 defvalue)
1887{
1888 if (!nla)
1889 return defvalue;
1890 return nla_get_u8(nla);
1891}
1892
1893/**
1894 * nla_get_u64 - return payload of u64 attribute
1895 * @nla: u64 netlink attribute
1896 */
1897static inline u64 nla_get_u64(const struct nlattr *nla)
1898{
1899 u64 tmp;
1900
1901 nla_memcpy(dest: &tmp, src: nla, count: sizeof(tmp));
1902
1903 return tmp;
1904}
1905
1906/**
1907 * nla_get_u64_default - return payload of u64 attribute or default
1908 * @nla: u64 netlink attribute, may be %NULL
1909 * @defvalue: default value to use if @nla is %NULL
1910 *
1911 * Return: the value of the attribute, or the default value if not present
1912 */
1913static inline u64 nla_get_u64_default(const struct nlattr *nla, u64 defvalue)
1914{
1915 if (!nla)
1916 return defvalue;
1917 return nla_get_u64(nla);
1918}
1919
1920/**
1921 * nla_get_uint - return payload of uint attribute
1922 * @nla: uint netlink attribute
1923 */
1924static inline u64 nla_get_uint(const struct nlattr *nla)
1925{
1926 if (nla_len(nla) == sizeof(u32))
1927 return nla_get_u32(nla);
1928 return nla_get_u64(nla);
1929}
1930
1931/**
1932 * nla_get_uint_default - return payload of uint attribute or default
1933 * @nla: uint netlink attribute, may be %NULL
1934 * @defvalue: default value to use if @nla is %NULL
1935 *
1936 * Return: the value of the attribute, or the default value if not present
1937 */
1938static inline u64 nla_get_uint_default(const struct nlattr *nla, u64 defvalue)
1939{
1940 if (!nla)
1941 return defvalue;
1942 return nla_get_uint(nla);
1943}
1944
1945/**
1946 * nla_get_be64 - return payload of __be64 attribute
1947 * @nla: __be64 netlink attribute
1948 */
1949static inline __be64 nla_get_be64(const struct nlattr *nla)
1950{
1951 __be64 tmp;
1952
1953 nla_memcpy(dest: &tmp, src: nla, count: sizeof(tmp));
1954
1955 return tmp;
1956}
1957
1958/**
1959 * nla_get_be64_default - return payload of be64 attribute or default
1960 * @nla: __be64 netlink attribute, may be %NULL
1961 * @defvalue: default value to use if @nla is %NULL
1962 *
1963 * Return: the value of the attribute, or the default value if not present
1964 */
1965static inline __be64 nla_get_be64_default(const struct nlattr *nla,
1966 __be64 defvalue)
1967{
1968 if (!nla)
1969 return defvalue;
1970 return nla_get_be64(nla);
1971}
1972
1973/**
1974 * nla_get_le64 - return payload of __le64 attribute
1975 * @nla: __le64 netlink attribute
1976 */
1977static inline __le64 nla_get_le64(const struct nlattr *nla)
1978{
1979 return *(__le64 *) nla_data(nla);
1980}
1981
1982/**
1983 * nla_get_le64_default - return payload of le64 attribute or default
1984 * @nla: __le64 netlink attribute, may be %NULL
1985 * @defvalue: default value to use if @nla is %NULL
1986 *
1987 * Return: the value of the attribute, or the default value if not present
1988 */
1989static inline __le64 nla_get_le64_default(const struct nlattr *nla,
1990 __le64 defvalue)
1991{
1992 if (!nla)
1993 return defvalue;
1994 return nla_get_le64(nla);
1995}
1996
1997/**
1998 * nla_get_s32 - return payload of s32 attribute
1999 * @nla: s32 netlink attribute
2000 */
2001static inline s32 nla_get_s32(const struct nlattr *nla)
2002{
2003 return *(s32 *) nla_data(nla);
2004}
2005
2006/**
2007 * nla_get_s32_default - return payload of s32 attribute or default
2008 * @nla: s32 netlink attribute, may be %NULL
2009 * @defvalue: default value to use if @nla is %NULL
2010 *
2011 * Return: the value of the attribute, or the default value if not present
2012 */
2013static inline s32 nla_get_s32_default(const struct nlattr *nla, s32 defvalue)
2014{
2015 if (!nla)
2016 return defvalue;
2017 return nla_get_s32(nla);
2018}
2019
2020/**
2021 * nla_get_s16 - return payload of s16 attribute
2022 * @nla: s16 netlink attribute
2023 */
2024static inline s16 nla_get_s16(const struct nlattr *nla)
2025{
2026 return *(s16 *) nla_data(nla);
2027}
2028
2029/**
2030 * nla_get_s16_default - return payload of s16 attribute or default
2031 * @nla: s16 netlink attribute, may be %NULL
2032 * @defvalue: default value to use if @nla is %NULL
2033 *
2034 * Return: the value of the attribute, or the default value if not present
2035 */
2036static inline s16 nla_get_s16_default(const struct nlattr *nla, s16 defvalue)
2037{
2038 if (!nla)
2039 return defvalue;
2040 return nla_get_s16(nla);
2041}
2042
2043/**
2044 * nla_get_s8 - return payload of s8 attribute
2045 * @nla: s8 netlink attribute
2046 */
2047static inline s8 nla_get_s8(const struct nlattr *nla)
2048{
2049 return *(s8 *) nla_data(nla);
2050}
2051
2052/**
2053 * nla_get_s8_default - return payload of s8 attribute or default
2054 * @nla: s8 netlink attribute, may be %NULL
2055 * @defvalue: default value to use if @nla is %NULL
2056 *
2057 * Return: the value of the attribute, or the default value if not present
2058 */
2059static inline s8 nla_get_s8_default(const struct nlattr *nla, s8 defvalue)
2060{
2061 if (!nla)
2062 return defvalue;
2063 return nla_get_s8(nla);
2064}
2065
2066/**
2067 * nla_get_s64 - return payload of s64 attribute
2068 * @nla: s64 netlink attribute
2069 */
2070static inline s64 nla_get_s64(const struct nlattr *nla)
2071{
2072 s64 tmp;
2073
2074 nla_memcpy(dest: &tmp, src: nla, count: sizeof(tmp));
2075
2076 return tmp;
2077}
2078
2079/**
2080 * nla_get_s64_default - return payload of s64 attribute or default
2081 * @nla: s64 netlink attribute, may be %NULL
2082 * @defvalue: default value to use if @nla is %NULL
2083 *
2084 * Return: the value of the attribute, or the default value if not present
2085 */
2086static inline s64 nla_get_s64_default(const struct nlattr *nla, s64 defvalue)
2087{
2088 if (!nla)
2089 return defvalue;
2090 return nla_get_s64(nla);
2091}
2092
2093/**
2094 * nla_get_sint - return payload of uint attribute
2095 * @nla: uint netlink attribute
2096 */
2097static inline s64 nla_get_sint(const struct nlattr *nla)
2098{
2099 if (nla_len(nla) == sizeof(s32))
2100 return nla_get_s32(nla);
2101 return nla_get_s64(nla);
2102}
2103
2104/**
2105 * nla_get_sint_default - return payload of sint attribute or default
2106 * @nla: sint netlink attribute, may be %NULL
2107 * @defvalue: default value to use if @nla is %NULL
2108 *
2109 * Return: the value of the attribute, or the default value if not present
2110 */
2111static inline s64 nla_get_sint_default(const struct nlattr *nla, s64 defvalue)
2112{
2113 if (!nla)
2114 return defvalue;
2115 return nla_get_sint(nla);
2116}
2117
2118/**
2119 * nla_get_flag - return payload of flag attribute
2120 * @nla: flag netlink attribute
2121 */
2122static inline int nla_get_flag(const struct nlattr *nla)
2123{
2124 return !!nla;
2125}
2126
2127/**
2128 * nla_get_msecs - return payload of msecs attribute
2129 * @nla: msecs netlink attribute
2130 *
2131 * Returns: the number of milliseconds in jiffies.
2132 */
2133static inline unsigned long nla_get_msecs(const struct nlattr *nla)
2134{
2135 u64 msecs = nla_get_u64(nla);
2136
2137 return msecs_to_jiffies(m: (unsigned long) msecs);
2138}
2139
2140/**
2141 * nla_get_msecs_default - return payload of msecs attribute or default
2142 * @nla: msecs netlink attribute, may be %NULL
2143 * @defvalue: default value to use if @nla is %NULL
2144 *
2145 * Return: the value of the attribute, or the default value if not present
2146 */
2147static inline unsigned long nla_get_msecs_default(const struct nlattr *nla,
2148 unsigned long defvalue)
2149{
2150 if (!nla)
2151 return defvalue;
2152 return nla_get_msecs(nla);
2153}
2154
2155/**
2156 * nla_get_in_addr - return payload of IPv4 address attribute
2157 * @nla: IPv4 address netlink attribute
2158 */
2159static inline __be32 nla_get_in_addr(const struct nlattr *nla)
2160{
2161 return *(__be32 *) nla_data(nla);
2162}
2163
2164/**
2165 * nla_get_in_addr_default - return payload of be32 attribute or default
2166 * @nla: IPv4 address netlink attribute, may be %NULL
2167 * @defvalue: default value to use if @nla is %NULL
2168 *
2169 * Return: the value of the attribute, or the default value if not present
2170 */
2171static inline __be32 nla_get_in_addr_default(const struct nlattr *nla,
2172 __be32 defvalue)
2173{
2174 if (!nla)
2175 return defvalue;
2176 return nla_get_in_addr(nla);
2177}
2178
2179/**
2180 * nla_get_in6_addr - return payload of IPv6 address attribute
2181 * @nla: IPv6 address netlink attribute
2182 */
2183static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
2184{
2185 struct in6_addr tmp;
2186
2187 nla_memcpy(dest: &tmp, src: nla, count: sizeof(tmp));
2188 return tmp;
2189}
2190
2191/**
2192 * nla_get_bitfield32 - return payload of 32 bitfield attribute
2193 * @nla: nla_bitfield32 attribute
2194 */
2195static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
2196{
2197 struct nla_bitfield32 tmp;
2198
2199 nla_memcpy(dest: &tmp, src: nla, count: sizeof(tmp));
2200 return tmp;
2201}
2202
2203/**
2204 * nla_memdup - duplicate attribute memory (kmemdup)
2205 * @src: netlink attribute to duplicate from
2206 * @gfp: GFP mask
2207 */
2208static inline void *nla_memdup_noprof(const struct nlattr *src, gfp_t gfp)
2209{
2210 return kmemdup_noprof(src: nla_data(nla: src), len: nla_len(nla: src), gfp);
2211}
2212#define nla_memdup(...) alloc_hooks(nla_memdup_noprof(__VA_ARGS__))
2213
2214/**
2215 * nla_nest_start_noflag - Start a new level of nested attributes
2216 * @skb: socket buffer to add attributes to
2217 * @attrtype: attribute type of container
2218 *
2219 * This function exists for backward compatibility to use in APIs which never
2220 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
2221 * nla_nest_start() which sets the flag.
2222 *
2223 * Returns: the container attribute or NULL on error
2224 */
2225static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
2226 int attrtype)
2227{
2228 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
2229
2230 if (nla_put(skb, attrtype, attrlen: 0, NULL) < 0)
2231 return NULL;
2232
2233 return start;
2234}
2235
2236/**
2237 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
2238 * @skb: socket buffer to add attributes to
2239 * @attrtype: attribute type of container
2240 *
2241 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
2242 * flag. This is the preferred function to use in new code.
2243 *
2244 * Returns: the container attribute or NULL on error
2245 */
2246static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
2247{
2248 return nla_nest_start_noflag(skb, attrtype: attrtype | NLA_F_NESTED);
2249}
2250
2251/**
2252 * nla_nest_end - Finalize nesting of attributes
2253 * @skb: socket buffer the attributes are stored in
2254 * @start: container attribute
2255 *
2256 * Corrects the container attribute header to include the all
2257 * appended attributes.
2258 *
2259 * Returns: the total data length of the skb.
2260 */
2261static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
2262{
2263 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
2264 return skb->len;
2265}
2266
2267/**
2268 * nla_nest_cancel - Cancel nesting of attributes
2269 * @skb: socket buffer the message is stored in
2270 * @start: container attribute
2271 *
2272 * Removes the container attribute and including all nested
2273 * attributes. Returns -EMSGSIZE
2274 */
2275static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
2276{
2277 nlmsg_trim(skb, mark: start);
2278}
2279
2280/**
2281 * nla_put_empty_nest - Create an empty nest
2282 * @skb: socket buffer the message is stored in
2283 * @attrtype: attribute type of the container
2284 *
2285 * This function is a helper for creating empty nests.
2286 *
2287 * Returns: 0 when successful or -EMSGSIZE on failure.
2288 */
2289static inline int nla_put_empty_nest(struct sk_buff *skb, int attrtype)
2290{
2291 return nla_nest_start(skb, attrtype) ? 0 : -EMSGSIZE;
2292}
2293
2294/**
2295 * __nla_validate_nested - Validate a stream of nested attributes
2296 * @start: container attribute
2297 * @maxtype: maximum attribute type to be expected
2298 * @policy: validation policy
2299 * @validate: validation strictness
2300 * @extack: extended ACK report struct
2301 *
2302 * Validates all attributes in the nested attribute stream against the
2303 * specified policy. Attributes with a type exceeding maxtype will be
2304 * ignored. See documentation of struct nla_policy for more details.
2305 *
2306 * Returns: 0 on success or a negative error code.
2307 */
2308static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
2309 const struct nla_policy *policy,
2310 unsigned int validate,
2311 struct netlink_ext_ack *extack)
2312{
2313 return __nla_validate(head: nla_data(nla: start), len: nla_len(nla: start), maxtype, policy,
2314 validate, extack);
2315}
2316
2317static inline int
2318nla_validate_nested(const struct nlattr *start, int maxtype,
2319 const struct nla_policy *policy,
2320 struct netlink_ext_ack *extack)
2321{
2322 return __nla_validate_nested(start, maxtype, policy,
2323 NL_VALIDATE_STRICT, extack);
2324}
2325
2326static inline int
2327nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
2328 const struct nla_policy *policy,
2329 struct netlink_ext_ack *extack)
2330{
2331 return __nla_validate_nested(start, maxtype, policy,
2332 validate: NL_VALIDATE_LIBERAL, extack);
2333}
2334
2335/**
2336 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
2337 * @skb: socket buffer the message is stored in
2338 *
2339 * Return: true if padding is needed to align the next attribute (nla_data()) to
2340 * a 64-bit aligned area.
2341 */
2342static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
2343{
2344#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2345 /* The nlattr header is 4 bytes in size, that's why we test
2346 * if the skb->data _is_ aligned. A NOP attribute, plus
2347 * nlattr header for next attribute, will make nla_data()
2348 * 8-byte aligned.
2349 */
2350 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
2351 return true;
2352#endif
2353 return false;
2354}
2355
2356/**
2357 * nla_align_64bit - 64-bit align the nla_data() of next attribute
2358 * @skb: socket buffer the message is stored in
2359 * @padattr: attribute type for the padding
2360 *
2361 * Conditionally emit a padding netlink attribute in order to make
2362 * the next attribute we emit have a 64-bit aligned nla_data() area.
2363 * This will only be done in architectures which do not have
2364 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
2365 *
2366 * Returns: zero on success or a negative error code.
2367 */
2368static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
2369{
2370 if (nla_need_padding_for_64bit(skb) &&
2371 !nla_reserve(skb, attrtype: padattr, attrlen: 0))
2372 return -EMSGSIZE;
2373
2374 return 0;
2375}
2376
2377/**
2378 * nla_total_size_64bit - total length of attribute including padding
2379 * @payload: length of payload
2380 */
2381static inline int nla_total_size_64bit(int payload)
2382{
2383 return NLA_ALIGN(nla_attr_size(payload))
2384#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2385 + NLA_ALIGN(nla_attr_size(0))
2386#endif
2387 ;
2388}
2389
2390/**
2391 * nla_for_each_attr - iterate over a stream of attributes
2392 * @pos: loop counter, set to current attribute
2393 * @head: head of attribute stream
2394 * @len: length of attribute stream
2395 * @rem: initialized to len, holds bytes currently remaining in stream
2396 */
2397#define nla_for_each_attr(pos, head, len, rem) \
2398 for (pos = head, rem = len; \
2399 nla_ok(pos, rem); \
2400 pos = nla_next(pos, &(rem)))
2401
2402/**
2403 * nla_for_each_attr_type - iterate over a stream of attributes
2404 * @pos: loop counter, set to current attribute
2405 * @type: required attribute type for @pos
2406 * @head: head of attribute stream
2407 * @len: length of attribute stream
2408 * @rem: initialized to len, holds bytes currently remaining in stream
2409 */
2410#define nla_for_each_attr_type(pos, type, head, len, rem) \
2411 nla_for_each_attr(pos, head, len, rem) \
2412 if (nla_type(pos) == type)
2413
2414/**
2415 * nla_for_each_nested - iterate over nested attributes
2416 * @pos: loop counter, set to current attribute
2417 * @nla: attribute containing the nested attributes
2418 * @rem: initialized to len, holds bytes currently remaining in stream
2419 */
2420#define nla_for_each_nested(pos, nla, rem) \
2421 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
2422
2423/**
2424 * nla_for_each_nested_type - iterate over nested attributes
2425 * @pos: loop counter, set to current attribute
2426 * @type: required attribute type for @pos
2427 * @nla: attribute containing the nested attributes
2428 * @rem: initialized to len, holds bytes currently remaining in stream
2429 */
2430#define nla_for_each_nested_type(pos, type, nla, rem) \
2431 nla_for_each_nested(pos, nla, rem) \
2432 if (nla_type(pos) == type)
2433
2434/**
2435 * nla_is_last - Test if attribute is last in stream
2436 * @nla: attribute to test
2437 * @rem: bytes remaining in stream
2438 */
2439static inline bool nla_is_last(const struct nlattr *nla, int rem)
2440{
2441 return nla->nla_len == rem;
2442}
2443
2444void nla_get_range_unsigned(const struct nla_policy *pt,
2445 struct netlink_range_validation *range);
2446void nla_get_range_signed(const struct nla_policy *pt,
2447 struct netlink_range_validation_signed *range);
2448
2449struct netlink_policy_dump_state;
2450
2451int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
2452 const struct nla_policy *policy,
2453 unsigned int maxtype);
2454int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
2455 const struct nla_policy *policy,
2456 unsigned int maxtype);
2457bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
2458int netlink_policy_dump_write(struct sk_buff *skb,
2459 struct netlink_policy_dump_state *state);
2460int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
2461int netlink_policy_dump_write_attr(struct sk_buff *skb,
2462 const struct nla_policy *pt,
2463 int nestattr);
2464void netlink_policy_dump_free(struct netlink_policy_dump_state *state);
2465
2466#endif
2467