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