1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __NET_NETLINK_H
3 #define __NET_NETLINK_H
5 #include <linux/types.h>
6 #include <linux/netlink.h>
7 #include <linux/jiffies.h>
10 /* ========================================================================
11 * Netlink Messages and Attributes Interface (As Seen On TV)
12 * ------------------------------------------------------------------------
14 * ------------------------------------------------------------------------
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)-----------------------+
26 * <---------------------- nlmsg_len(nlh) --------------------->
27 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
28 * +----------------------+- - -+--------------------------------+
29 * | Family Header | Pad | Attributes |
30 * +----------------------+- - -+--------------------------------+
31 * nlmsg_attrdata(nlh, hdrlen)---^
34 * struct nlmsghdr netlink message header
36 * Message Construction:
37 * nlmsg_new() create a new netlink message
38 * nlmsg_put() add a netlink message to an skb
39 * nlmsg_put_answer() callback based nlmsg_put()
40 * nlmsg_end() finalize netlink message
41 * nlmsg_get_pos() return current position in message
42 * nlmsg_trim() trim part of message
43 * nlmsg_cancel() cancel message construction
44 * nlmsg_free() free a netlink message
47 * nlmsg_multicast() multicast message to several groups
48 * nlmsg_unicast() unicast a message to a single socket
49 * nlmsg_notify() send notification message
51 * Message Length Calculations:
52 * nlmsg_msg_size(payload) length of message w/o padding
53 * nlmsg_total_size(payload) length of message w/ padding
54 * nlmsg_padlen(payload) length of padding at tail
56 * Message Payload Access:
57 * nlmsg_data(nlh) head of message payload
58 * nlmsg_len(nlh) length of message payload
59 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
60 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
63 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
64 * nlmsg_next(nlh, remaining) get next netlink message
65 * nlmsg_parse() parse attributes of a message
66 * nlmsg_find_attr() find an attribute in a message
67 * nlmsg_for_each_msg() loop over all messages
68 * nlmsg_validate() validate netlink message incl. attrs
69 * nlmsg_for_each_attr() loop over all attributes
72 * nlmsg_report() report back to application?
74 * ------------------------------------------------------------------------
75 * Attributes Interface
76 * ------------------------------------------------------------------------
79 * <------- nla_total_size(payload) ------->
80 * <---- nla_attr_size(payload) ----->
81 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
82 * | Header | Pad | Payload | Pad | Header
83 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
84 * <- nla_len(nla) -> ^
85 * nla_data(nla)----^ |
86 * nla_next(nla)-----------------------------'
89 * struct nlattr netlink attribute header
91 * Attribute Construction:
92 * nla_reserve(skb, type, len) reserve room for an attribute
93 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
94 * nla_put(skb, type, len, data) add attribute to skb
95 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
96 * nla_append(skb, len, data) append data to skb
98 * Attribute Construction for Basic Types:
99 * nla_put_u8(skb, type, value) add u8 attribute to skb
100 * nla_put_u16(skb, type, value) add u16 attribute to skb
101 * nla_put_u32(skb, type, value) add u32 attribute to skb
102 * nla_put_u64_64bit(skb, type,
103 * value, padattr) add u64 attribute to skb
104 * nla_put_s8(skb, type, value) add s8 attribute to skb
105 * nla_put_s16(skb, type, value) add s16 attribute to skb
106 * nla_put_s32(skb, type, value) add s32 attribute to skb
107 * nla_put_s64(skb, type, value,
108 * padattr) add s64 attribute to skb
109 * nla_put_string(skb, type, str) add string attribute to skb
110 * nla_put_flag(skb, type) add flag attribute to skb
111 * nla_put_msecs(skb, type, jiffies,
112 * padattr) add msecs attribute to skb
113 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb
114 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb
116 * Nested Attributes Construction:
117 * nla_nest_start(skb, type) start a nested attribute
118 * nla_nest_end(skb, nla) finalize a nested attribute
119 * nla_nest_cancel(skb, nla) cancel nested attribute construction
121 * Attribute Length Calculations:
122 * nla_attr_size(payload) length of attribute w/o padding
123 * nla_total_size(payload) length of attribute w/ padding
124 * nla_padlen(payload) length of padding
126 * Attribute Payload Access:
127 * nla_data(nla) head of attribute payload
128 * nla_len(nla) length of attribute payload
130 * Attribute Payload Access for Basic Types:
131 * nla_get_u8(nla) get payload for a u8 attribute
132 * nla_get_u16(nla) get payload for a u16 attribute
133 * nla_get_u32(nla) get payload for a u32 attribute
134 * nla_get_u64(nla) get payload for a u64 attribute
135 * nla_get_s8(nla) get payload for a s8 attribute
136 * nla_get_s16(nla) get payload for a s16 attribute
137 * nla_get_s32(nla) get payload for a s32 attribute
138 * nla_get_s64(nla) get payload for a s64 attribute
139 * nla_get_flag(nla) return 1 if flag is true
140 * nla_get_msecs(nla) get payload for a msecs attribute
143 * nla_memcpy(dest, nla, count) copy attribute into memory
144 * nla_memcmp(nla, data, size) compare attribute with memory area
145 * nla_strscpy(dst, nla, size) copy attribute to a sized string
146 * nla_strcmp(nla, str) compare attribute with string
149 * nla_ok(nla, remaining) does nla fit into remaining bytes?
150 * nla_next(nla, remaining) get next netlink attribute
151 * nla_validate() validate a stream of attributes
152 * nla_validate_nested() validate a stream of nested attributes
153 * nla_find() find attribute in stream of attributes
154 * nla_find_nested() find attribute in nested attributes
155 * nla_parse() parse and validate stream of attrs
156 * nla_parse_nested() parse nested attributes
157 * nla_for_each_attr() loop over all attributes
158 * nla_for_each_nested() loop over the nested attributes
159 *=========================================================================
163 * Standard attribute types to specify validation policy
189 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
191 struct netlink_range_validation {
195 struct netlink_range_validation_signed {
199 enum nla_policy_validation {
202 NLA_VALIDATE_RANGE_WARN_TOO_LONG,
206 NLA_VALIDATE_RANGE_PTR,
207 NLA_VALIDATE_FUNCTION,
211 * struct nla_policy - attribute validation policy
212 * @type: Type of attribute or NLA_UNSPEC
213 * @validation_type: type of attribute validation done in addition to
214 * type-specific validation (e.g. range, function call), see
215 * &enum nla_policy_validation
216 * @len: Type specific length of payload
218 * Policies are defined as arrays of this struct, the array must be
219 * accessible by attribute type up to the highest identifier to be expected.
221 * Meaning of `len' field:
222 * NLA_STRING Maximum length of string
223 * NLA_NUL_STRING Maximum length of string (excluding NUL)
225 * NLA_BINARY Maximum length of attribute payload
226 * (but see also below with the validation type)
228 * NLA_NESTED_ARRAY Length verification is done by checking len of
229 * nested header (or empty); len field is used if
230 * nested_policy is also used, for the max attr
231 * number in the nested policy.
236 * NLA_BE16, NLA_BE32,
237 * NLA_MSECS Leaving the length field zero will verify the
238 * given type fits, using it verifies minimum length
239 * just like "All other"
240 * NLA_BITFIELD32 Unused
242 * All other Minimum length of attribute payload
244 * Meaning of validation union:
245 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and
246 * `bitfield32_valid' is the u32 value of valid flags
247 * NLA_REJECT This attribute is always rejected and `reject_message'
248 * may point to a string to report as the error instead
249 * of the generic one in extended ACK.
250 * NLA_NESTED `nested_policy' to a nested policy to validate, must
251 * also set `len' to the max attribute number. Use the
252 * provided NLA_POLICY_NESTED() macro.
253 * Note that nla_parse() will validate, but of course not
254 * parse, the nested sub-policies.
255 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate,
256 * must also set `len' to the max attribute number. Use
257 * the provided NLA_POLICY_NESTED_ARRAY() macro.
258 * The difference to NLA_NESTED is the structure:
259 * NLA_NESTED has the nested attributes directly inside
260 * while an array has the nested attributes at another
261 * level down and the attribute types directly in the
262 * nesting don't matter.
272 * NLA_S64 The `min' and `max' fields are used depending on the
273 * validation_type field, if that is min/max/range then
274 * the min, max or both are used (respectively) to check
275 * the value of the integer attribute.
276 * Note that in the interest of code simplicity and
277 * struct size both limits are s16, so you cannot
278 * enforce a range that doesn't fall within the range
279 * of s16 - do that as usual in the code instead.
280 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
281 * NLA_POLICY_RANGE() macros.
285 * NLA_U64 If the validation_type field instead is set to
286 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
287 * to a struct netlink_range_validation that indicates
288 * the min/max values.
289 * Use NLA_POLICY_FULL_RANGE().
293 * NLA_S64 If the validation_type field instead is set to
294 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
295 * pointer to a struct netlink_range_validation_signed
296 * that indicates the min/max values.
297 * Use NLA_POLICY_FULL_RANGE_SIGNED().
299 * NLA_BINARY If the validation type is like the ones for integers
300 * above, then the min/max length (not value like for
301 * integers) of the attribute is enforced.
303 * All other Unused - but note that it's a union
305 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
306 * NLA_BINARY Validation function called for the attribute.
307 * All other Unused - but note that it's a union
311 * static const u32 myvalidflags = 0xff231023;
313 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
314 * [ATTR_FOO] = { .type = NLA_U16 },
315 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
316 * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)),
317 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
326 * @strict_start_type: first attribute to validate strictly
328 * This entry is special, and used for the attribute at index 0
329 * only, and specifies special data about the policy, namely it
330 * specifies the "boundary type" where strict length validation
331 * starts for any attribute types >= this value, also, strict
332 * nesting validation starts here.
334 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
335 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to
336 * get the previous pure { .len = xyz } behaviour. The advantage
337 * of this is that types not specified in the policy will be
340 * For completely new families it should be set to 1 so that the
341 * validation is enforced for all attributes. For existing ones
342 * it should be set at least when new attributes are added to
343 * the enum used by the policy, and be set to the new value that
344 * was added to enforce strict validation from thereon.
346 u16 strict_start_type;
348 /* private: use NLA_POLICY_*() to set */
349 const u32 bitfield32_valid;
351 const char *reject_message;
352 const struct nla_policy *nested_policy;
353 struct netlink_range_validation *range;
354 struct netlink_range_validation_signed *range_signed;
358 int (*validate)(const struct nlattr *attr,
359 struct netlink_ext_ack *extack);
363 #define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN)
364 #define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
366 #define _NLA_POLICY_NESTED(maxattr, policy) \
367 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
368 #define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
369 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
370 #define NLA_POLICY_NESTED(policy) \
371 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
372 #define NLA_POLICY_NESTED_ARRAY(policy) \
373 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
374 #define NLA_POLICY_BITFIELD32(valid) \
375 { .type = NLA_BITFIELD32, .bitfield32_valid = valid }
377 #define __NLA_IS_UINT_TYPE(tp) \
378 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || tp == NLA_U64)
379 #define __NLA_IS_SINT_TYPE(tp) \
380 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64)
381 #define __NLA_IS_BEINT_TYPE(tp) \
382 (tp == NLA_BE16 || tp == NLA_BE32)
384 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
385 #define NLA_ENSURE_UINT_TYPE(tp) \
386 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
387 #define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \
388 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
390 tp == NLA_BINARY) + tp)
391 #define NLA_ENSURE_SINT_TYPE(tp) \
392 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
393 #define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \
394 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
395 __NLA_IS_SINT_TYPE(tp) || \
396 __NLA_IS_BEINT_TYPE(tp) || \
398 tp == NLA_BINARY) + tp)
399 #define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
400 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \
401 tp != NLA_REJECT && \
402 tp != NLA_NESTED && \
403 tp != NLA_NESTED_ARRAY) + tp)
404 #define NLA_ENSURE_BEINT_TYPE(tp) \
405 (__NLA_ENSURE(__NLA_IS_BEINT_TYPE(tp)) + tp)
407 #define NLA_POLICY_RANGE(tp, _min, _max) { \
408 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
409 .validation_type = NLA_VALIDATE_RANGE, \
414 #define NLA_POLICY_FULL_RANGE(tp, _range) { \
415 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \
416 .validation_type = NLA_VALIDATE_RANGE_PTR, \
420 #define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \
421 .type = NLA_ENSURE_SINT_TYPE(tp), \
422 .validation_type = NLA_VALIDATE_RANGE_PTR, \
423 .range_signed = _range, \
426 #define NLA_POLICY_MIN(tp, _min) { \
427 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
428 .validation_type = NLA_VALIDATE_MIN, \
432 #define NLA_POLICY_MAX(tp, _max) { \
433 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
434 .validation_type = NLA_VALIDATE_MAX, \
438 #define NLA_POLICY_MASK(tp, _mask) { \
439 .type = NLA_ENSURE_UINT_TYPE(tp), \
440 .validation_type = NLA_VALIDATE_MASK, \
444 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \
445 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \
446 .validation_type = NLA_VALIDATE_FUNCTION, \
448 .len = __VA_ARGS__ + 0, \
451 #define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
452 #define NLA_POLICY_EXACT_LEN_WARN(_len) { \
453 .type = NLA_BINARY, \
454 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \
458 #define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len)
461 * struct nl_info - netlink source information
462 * @nlh: Netlink message header of original request
463 * @nl_net: Network namespace
464 * @portid: Netlink PORTID of requesting application
465 * @skip_notify: Skip netlink notifications to user space
466 * @skip_notify_kernel: Skip selected in-kernel notifications
469 struct nlmsghdr *nlh;
473 skip_notify_kernel:1;
477 * enum netlink_validation - netlink message/attribute validation levels
478 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
479 * extra data at the end of the message, attributes being longer than
480 * they should be, or unknown attributes being present.
481 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
482 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
483 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
484 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
485 * This can safely be set by the kernel when the given policy has no
486 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
487 * are enforced going forward.
488 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
489 * U8, U16, U32 must have exact size, etc.)
490 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
491 * and unset for other policies.
493 enum netlink_validation {
494 NL_VALIDATE_LIBERAL = 0,
495 NL_VALIDATE_TRAILING = BIT(0),
496 NL_VALIDATE_MAXTYPE = BIT(1),
497 NL_VALIDATE_UNSPEC = BIT(2),
498 NL_VALIDATE_STRICT_ATTRS = BIT(3),
499 NL_VALIDATE_NESTED = BIT(4),
502 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
504 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
505 NL_VALIDATE_MAXTYPE |\
506 NL_VALIDATE_UNSPEC |\
507 NL_VALIDATE_STRICT_ATTRS |\
510 int netlink_rcv_skb(struct sk_buff *skb,
511 int (*cb)(struct sk_buff *, struct nlmsghdr *,
512 struct netlink_ext_ack *));
513 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
514 unsigned int group, int report, gfp_t flags);
516 int __nla_validate(const struct nlattr *head, int len, int maxtype,
517 const struct nla_policy *policy, unsigned int validate,
518 struct netlink_ext_ack *extack);
519 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
520 int len, const struct nla_policy *policy, unsigned int validate,
521 struct netlink_ext_ack *extack);
522 int nla_policy_len(const struct nla_policy *, int);
523 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
524 ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
525 char *nla_strdup(const struct nlattr *nla, gfp_t flags);
526 int nla_memcpy(void *dest, const struct nlattr *src, int count);
527 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
528 int nla_strcmp(const struct nlattr *nla, const char *str);
529 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
530 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
531 int attrlen, int padattr);
532 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
533 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
534 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
535 int attrlen, int padattr);
536 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
537 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
539 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
540 const void *data, int padattr);
541 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
542 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
543 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
544 const void *data, int padattr);
545 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
546 int nla_append(struct sk_buff *skb, int attrlen, const void *data);
548 /**************************************************************************
550 **************************************************************************/
553 * nlmsg_msg_size - length of netlink message not including padding
554 * @payload: length of message payload
556 static inline int nlmsg_msg_size(int payload)
558 return NLMSG_HDRLEN + payload;
562 * nlmsg_total_size - length of netlink message including padding
563 * @payload: length of message payload
565 static inline int nlmsg_total_size(int payload)
567 return NLMSG_ALIGN(nlmsg_msg_size(payload));
571 * nlmsg_padlen - length of padding at the message's tail
572 * @payload: length of message payload
574 static inline int nlmsg_padlen(int payload)
576 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
580 * nlmsg_data - head of message payload
581 * @nlh: netlink message header
583 static inline void *nlmsg_data(const struct nlmsghdr *nlh)
585 return (unsigned char *) nlh + NLMSG_HDRLEN;
589 * nlmsg_len - length of message payload
590 * @nlh: netlink message header
592 static inline int nlmsg_len(const struct nlmsghdr *nlh)
594 return nlh->nlmsg_len - NLMSG_HDRLEN;
598 * nlmsg_attrdata - head of attributes data
599 * @nlh: netlink message header
600 * @hdrlen: length of family specific header
602 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
605 unsigned char *data = nlmsg_data(nlh);
606 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
610 * nlmsg_attrlen - length of attributes data
611 * @nlh: netlink message header
612 * @hdrlen: length of family specific header
614 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
616 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
620 * nlmsg_ok - check if the netlink message fits into the remaining bytes
621 * @nlh: netlink message header
622 * @remaining: number of bytes remaining in message stream
624 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
626 return (remaining >= (int) sizeof(struct nlmsghdr) &&
627 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
628 nlh->nlmsg_len <= remaining);
632 * nlmsg_next - next netlink message in message stream
633 * @nlh: netlink message header
634 * @remaining: number of bytes remaining in message stream
636 * Returns the next netlink message in the message stream and
637 * decrements remaining by the size of the current message.
639 static inline struct nlmsghdr *
640 nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
642 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
644 *remaining -= totlen;
646 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
650 * nla_parse - Parse a stream of attributes into a tb buffer
651 * @tb: destination array with maxtype+1 elements
652 * @maxtype: maximum attribute type to be expected
653 * @head: head of attribute stream
654 * @len: length of attribute stream
655 * @policy: validation policy
656 * @extack: extended ACK pointer
658 * Parses a stream of attributes and stores a pointer to each attribute in
659 * the tb array accessible via the attribute type. Attributes with a type
660 * exceeding maxtype will be rejected, policy must be specified, attributes
661 * will be validated in the strictest way possible.
663 * Returns 0 on success or a negative error code.
665 static inline int nla_parse(struct nlattr **tb, int maxtype,
666 const struct nlattr *head, int len,
667 const struct nla_policy *policy,
668 struct netlink_ext_ack *extack)
670 return __nla_parse(tb, maxtype, head, len, policy,
671 NL_VALIDATE_STRICT, extack);
675 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
676 * @tb: destination array with maxtype+1 elements
677 * @maxtype: maximum attribute type to be expected
678 * @head: head of attribute stream
679 * @len: length of attribute stream
680 * @policy: validation policy
681 * @extack: extended ACK pointer
683 * Parses a stream of attributes and stores a pointer to each attribute in
684 * the tb array accessible via the attribute type. Attributes with a type
685 * exceeding maxtype will be ignored and attributes from the policy are not
686 * always strictly validated (only for new attributes).
688 * Returns 0 on success or a negative error code.
690 static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
691 const struct nlattr *head, int len,
692 const struct nla_policy *policy,
693 struct netlink_ext_ack *extack)
695 return __nla_parse(tb, maxtype, head, len, policy,
696 NL_VALIDATE_LIBERAL, extack);
700 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
701 * @tb: destination array with maxtype+1 elements
702 * @maxtype: maximum attribute type to be expected
703 * @head: head of attribute stream
704 * @len: length of attribute stream
705 * @policy: validation policy
706 * @extack: extended ACK pointer
708 * Parses a stream of attributes and stores a pointer to each attribute in
709 * the tb array accessible via the attribute type. Attributes with a type
710 * exceeding maxtype will be rejected as well as trailing data, but the
711 * policy is not completely strictly validated (only for new attributes).
713 * Returns 0 on success or a negative error code.
715 static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
716 const struct nlattr *head,
718 const struct nla_policy *policy,
719 struct netlink_ext_ack *extack)
721 return __nla_parse(tb, maxtype, head, len, policy,
722 NL_VALIDATE_DEPRECATED_STRICT, extack);
726 * __nlmsg_parse - parse attributes of a netlink message
727 * @nlh: netlink message header
728 * @hdrlen: length of family specific header
729 * @tb: destination array with maxtype+1 elements
730 * @maxtype: maximum attribute type to be expected
731 * @policy: validation policy
732 * @validate: validation strictness
733 * @extack: extended ACK report struct
737 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
738 struct nlattr *tb[], int maxtype,
739 const struct nla_policy *policy,
740 unsigned int validate,
741 struct netlink_ext_ack *extack)
743 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
744 NL_SET_ERR_MSG(extack, "Invalid header length");
748 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
749 nlmsg_attrlen(nlh, hdrlen), policy, validate,
754 * nlmsg_parse - parse attributes of a netlink message
755 * @nlh: netlink message header
756 * @hdrlen: length of family specific header
757 * @tb: destination array with maxtype+1 elements
758 * @maxtype: maximum attribute type to be expected
759 * @policy: validation policy
760 * @extack: extended ACK report struct
764 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
765 struct nlattr *tb[], int maxtype,
766 const struct nla_policy *policy,
767 struct netlink_ext_ack *extack)
769 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
770 NL_VALIDATE_STRICT, extack);
774 * nlmsg_parse_deprecated - parse attributes of a netlink message
775 * @nlh: netlink message header
776 * @hdrlen: length of family specific header
777 * @tb: destination array with maxtype+1 elements
778 * @maxtype: maximum attribute type to be expected
779 * @policy: validation policy
780 * @extack: extended ACK report struct
782 * See nla_parse_deprecated()
784 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
785 struct nlattr *tb[], int maxtype,
786 const struct nla_policy *policy,
787 struct netlink_ext_ack *extack)
789 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
790 NL_VALIDATE_LIBERAL, extack);
794 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
795 * @nlh: netlink message header
796 * @hdrlen: length of family specific header
797 * @tb: destination array with maxtype+1 elements
798 * @maxtype: maximum attribute type to be expected
799 * @policy: validation policy
800 * @extack: extended ACK report struct
802 * See nla_parse_deprecated_strict()
805 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
806 struct nlattr *tb[], int maxtype,
807 const struct nla_policy *policy,
808 struct netlink_ext_ack *extack)
810 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
811 NL_VALIDATE_DEPRECATED_STRICT, extack);
815 * nlmsg_find_attr - find a specific attribute in a netlink message
816 * @nlh: netlink message header
817 * @hdrlen: length of familiy specific header
818 * @attrtype: type of attribute to look for
820 * Returns the first attribute which matches the specified type.
822 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
823 int hdrlen, int attrtype)
825 return nla_find(nlmsg_attrdata(nlh, hdrlen),
826 nlmsg_attrlen(nlh, hdrlen), attrtype);
830 * nla_validate_deprecated - Validate a stream of attributes
831 * @head: head of attribute stream
832 * @len: length of attribute stream
833 * @maxtype: maximum attribute type to be expected
834 * @policy: validation policy
835 * @extack: extended ACK report struct
837 * Validates all attributes in the specified attribute stream against the
838 * specified policy. Validation is done in liberal mode.
839 * See documenation of struct nla_policy for more details.
841 * Returns 0 on success or a negative error code.
843 static inline int nla_validate_deprecated(const struct nlattr *head, int len,
845 const struct nla_policy *policy,
846 struct netlink_ext_ack *extack)
848 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
853 * nla_validate - Validate a stream of attributes
854 * @head: head of attribute stream
855 * @len: length of attribute stream
856 * @maxtype: maximum attribute type to be expected
857 * @policy: validation policy
858 * @extack: extended ACK report struct
860 * Validates all attributes in the specified attribute stream against the
861 * specified policy. Validation is done in strict mode.
862 * See documenation of struct nla_policy for more details.
864 * Returns 0 on success or a negative error code.
866 static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
867 const struct nla_policy *policy,
868 struct netlink_ext_ack *extack)
870 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
875 * nlmsg_validate_deprecated - validate a netlink message including attributes
876 * @nlh: netlinket message header
877 * @hdrlen: length of familiy specific header
878 * @maxtype: maximum attribute type to be expected
879 * @policy: validation policy
880 * @extack: extended ACK report struct
882 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
883 int hdrlen, int maxtype,
884 const struct nla_policy *policy,
885 struct netlink_ext_ack *extack)
887 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
890 return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
891 nlmsg_attrlen(nlh, hdrlen), maxtype,
892 policy, NL_VALIDATE_LIBERAL, extack);
898 * nlmsg_report - need to report back to application?
899 * @nlh: netlink message header
901 * Returns 1 if a report back to the application is requested.
903 static inline int nlmsg_report(const struct nlmsghdr *nlh)
905 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
909 * nlmsg_for_each_attr - iterate over a stream of attributes
910 * @pos: loop counter, set to current attribute
911 * @nlh: netlink message header
912 * @hdrlen: length of familiy specific header
913 * @rem: initialized to len, holds bytes currently remaining in stream
915 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
916 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
917 nlmsg_attrlen(nlh, hdrlen), rem)
920 * nlmsg_put - Add a new netlink message to an skb
921 * @skb: socket buffer to store message in
922 * @portid: netlink PORTID of requesting application
923 * @seq: sequence number of message
924 * @type: message type
925 * @payload: length of message payload
926 * @flags: message flags
928 * Returns NULL if the tailroom of the skb is insufficient to store
929 * the message header and payload.
931 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
932 int type, int payload, int flags)
934 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
937 return __nlmsg_put(skb, portid, seq, type, payload, flags);
941 * nlmsg_put_answer - Add a new callback based netlink message to an skb
942 * @skb: socket buffer to store message in
943 * @cb: netlink callback
944 * @type: message type
945 * @payload: length of message payload
946 * @flags: message flags
948 * Returns NULL if the tailroom of the skb is insufficient to store
949 * the message header and payload.
951 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
952 struct netlink_callback *cb,
953 int type, int payload,
956 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
957 type, payload, flags);
961 * nlmsg_new - Allocate a new netlink message
962 * @payload: size of the message payload
963 * @flags: the type of memory to allocate.
965 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
966 * and a good default is needed.
968 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
970 return alloc_skb(nlmsg_total_size(payload), flags);
974 * nlmsg_end - Finalize a netlink message
975 * @skb: socket buffer the message is stored in
976 * @nlh: netlink message header
978 * Corrects the netlink message header to include the appeneded
979 * attributes. Only necessary if attributes have been added to
982 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
984 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
988 * nlmsg_get_pos - return current position in netlink message
989 * @skb: socket buffer the message is stored in
991 * Returns a pointer to the current tail of the message.
993 static inline void *nlmsg_get_pos(struct sk_buff *skb)
995 return skb_tail_pointer(skb);
999 * nlmsg_trim - Trim message to a mark
1000 * @skb: socket buffer the message is stored in
1001 * @mark: mark to trim to
1003 * Trims the message to the provided mark.
1005 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1008 WARN_ON((unsigned char *) mark < skb->data);
1009 skb_trim(skb, (unsigned char *) mark - skb->data);
1014 * nlmsg_cancel - Cancel construction of a netlink message
1015 * @skb: socket buffer the message is stored in
1016 * @nlh: netlink message header
1018 * Removes the complete netlink message including all
1019 * attributes from the socket buffer again.
1021 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1023 nlmsg_trim(skb, nlh);
1027 * nlmsg_free - free a netlink message
1028 * @skb: socket buffer of netlink message
1030 static inline void nlmsg_free(struct sk_buff *skb)
1036 * nlmsg_multicast - multicast a netlink message
1037 * @sk: netlink socket to spread messages to
1038 * @skb: netlink message as socket buffer
1039 * @portid: own netlink portid to avoid sending to yourself
1040 * @group: multicast group id
1041 * @flags: allocation flags
1043 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1044 u32 portid, unsigned int group, gfp_t flags)
1048 NETLINK_CB(skb).dst_group = group;
1050 err = netlink_broadcast(sk, skb, portid, group, flags);
1058 * nlmsg_unicast - unicast a netlink message
1059 * @sk: netlink socket to spread message to
1060 * @skb: netlink message as socket buffer
1061 * @portid: netlink portid of the destination socket
1063 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1067 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1075 * nlmsg_for_each_msg - iterate over a stream of messages
1076 * @pos: loop counter, set to current message
1077 * @head: head of message stream
1078 * @len: length of message stream
1079 * @rem: initialized to len, holds bytes currently remaining in stream
1081 #define nlmsg_for_each_msg(pos, head, len, rem) \
1082 for (pos = head, rem = len; \
1083 nlmsg_ok(pos, rem); \
1084 pos = nlmsg_next(pos, &(rem)))
1087 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1088 * @cb: netlink callback structure that stores the sequence number
1089 * @nlh: netlink message header to write the flag to
1091 * This function checks if the sequence (generation) number changed during dump
1092 * and if it did, advertises it in the netlink message header.
1094 * The correct way to use it is to set cb->seq to the generation counter when
1095 * all locks for dumping have been acquired, and then call this function for
1096 * each message that is generated.
1098 * Note that due to initialisation concerns, 0 is an invalid sequence number
1099 * and must not be used by code that uses this functionality.
1102 nl_dump_check_consistent(struct netlink_callback *cb,
1103 struct nlmsghdr *nlh)
1105 if (cb->prev_seq && cb->seq != cb->prev_seq)
1106 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1107 cb->prev_seq = cb->seq;
1110 /**************************************************************************
1111 * Netlink Attributes
1112 **************************************************************************/
1115 * nla_attr_size - length of attribute not including padding
1116 * @payload: length of payload
1118 static inline int nla_attr_size(int payload)
1120 return NLA_HDRLEN + payload;
1124 * nla_total_size - total length of attribute including padding
1125 * @payload: length of payload
1127 static inline int nla_total_size(int payload)
1129 return NLA_ALIGN(nla_attr_size(payload));
1133 * nla_padlen - length of padding at the tail of attribute
1134 * @payload: length of payload
1136 static inline int nla_padlen(int payload)
1138 return nla_total_size(payload) - nla_attr_size(payload);
1142 * nla_type - attribute type
1143 * @nla: netlink attribute
1145 static inline int nla_type(const struct nlattr *nla)
1147 return nla->nla_type & NLA_TYPE_MASK;
1151 * nla_data - head of payload
1152 * @nla: netlink attribute
1154 static inline void *nla_data(const struct nlattr *nla)
1156 return (char *) nla + NLA_HDRLEN;
1160 * nla_len - length of payload
1161 * @nla: netlink attribute
1163 static inline int nla_len(const struct nlattr *nla)
1165 return nla->nla_len - NLA_HDRLEN;
1169 * nla_ok - check if the netlink attribute fits into the remaining bytes
1170 * @nla: netlink attribute
1171 * @remaining: number of bytes remaining in attribute stream
1173 static inline int nla_ok(const struct nlattr *nla, int remaining)
1175 return remaining >= (int) sizeof(*nla) &&
1176 nla->nla_len >= sizeof(*nla) &&
1177 nla->nla_len <= remaining;
1181 * nla_next - next netlink attribute in attribute stream
1182 * @nla: netlink attribute
1183 * @remaining: number of bytes remaining in attribute stream
1185 * Returns the next netlink attribute in the attribute stream and
1186 * decrements remaining by the size of the current attribute.
1188 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1190 unsigned int totlen = NLA_ALIGN(nla->nla_len);
1192 *remaining -= totlen;
1193 return (struct nlattr *) ((char *) nla + totlen);
1197 * nla_find_nested - find attribute in a set of nested attributes
1198 * @nla: attribute containing the nested attributes
1199 * @attrtype: type of attribute to look for
1201 * Returns the first attribute which matches the specified type.
1203 static inline struct nlattr *
1204 nla_find_nested(const struct nlattr *nla, int attrtype)
1206 return nla_find(nla_data(nla), nla_len(nla), attrtype);
1210 * nla_parse_nested - parse nested attributes
1211 * @tb: destination array with maxtype+1 elements
1212 * @maxtype: maximum attribute type to be expected
1213 * @nla: attribute containing the nested attributes
1214 * @policy: validation policy
1215 * @extack: extended ACK report struct
1219 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1220 const struct nlattr *nla,
1221 const struct nla_policy *policy,
1222 struct netlink_ext_ack *extack)
1224 if (!(nla->nla_type & NLA_F_NESTED)) {
1225 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1229 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1230 NL_VALIDATE_STRICT, extack);
1234 * nla_parse_nested_deprecated - parse nested attributes
1235 * @tb: destination array with maxtype+1 elements
1236 * @maxtype: maximum attribute type to be expected
1237 * @nla: attribute containing the nested attributes
1238 * @policy: validation policy
1239 * @extack: extended ACK report struct
1241 * See nla_parse_deprecated()
1243 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1244 const struct nlattr *nla,
1245 const struct nla_policy *policy,
1246 struct netlink_ext_ack *extack)
1248 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1249 NL_VALIDATE_LIBERAL, extack);
1253 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1254 * @skb: socket buffer to add attribute to
1255 * @attrtype: attribute type
1256 * @value: numeric value
1258 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1260 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
1263 return nla_put(skb, attrtype, sizeof(u8), &tmp);
1267 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1268 * @skb: socket buffer to add attribute to
1269 * @attrtype: attribute type
1270 * @value: numeric value
1272 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1276 return nla_put(skb, attrtype, sizeof(u16), &tmp);
1280 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1281 * @skb: socket buffer to add attribute to
1282 * @attrtype: attribute type
1283 * @value: numeric value
1285 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1289 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1293 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1294 * @skb: socket buffer to add attribute to
1295 * @attrtype: attribute type
1296 * @value: numeric value
1298 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1302 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1306 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1307 * @skb: socket buffer to add attribute to
1308 * @attrtype: attribute type
1309 * @value: numeric value
1311 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1315 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1319 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1320 * @skb: socket buffer to add attribute to
1321 * @attrtype: attribute type
1322 * @value: numeric value
1324 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1328 return nla_put(skb, attrtype, sizeof(u32), &tmp);
1332 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1333 * @skb: socket buffer to add attribute to
1334 * @attrtype: attribute type
1335 * @value: numeric value
1337 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1341 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1345 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1346 * @skb: socket buffer to add attribute to
1347 * @attrtype: attribute type
1348 * @value: numeric value
1350 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1354 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1358 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1359 * @skb: socket buffer to add attribute to
1360 * @attrtype: attribute type
1361 * @value: numeric value
1363 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1367 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1371 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1372 * @skb: socket buffer to add attribute to
1373 * @attrtype: attribute type
1374 * @value: numeric value
1375 * @padattr: attribute type for the padding
1377 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1378 u64 value, int padattr)
1382 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1386 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1387 * @skb: socket buffer to add attribute to
1388 * @attrtype: attribute type
1389 * @value: numeric value
1390 * @padattr: attribute type for the padding
1392 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1397 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1401 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1402 * @skb: socket buffer to add attribute to
1403 * @attrtype: attribute type
1404 * @value: numeric value
1405 * @padattr: attribute type for the padding
1407 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1412 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1417 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1418 * @skb: socket buffer to add attribute to
1419 * @attrtype: attribute type
1420 * @value: numeric value
1421 * @padattr: attribute type for the padding
1423 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1428 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1432 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1433 * @skb: socket buffer to add attribute to
1434 * @attrtype: attribute type
1435 * @value: numeric value
1437 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1441 return nla_put(skb, attrtype, sizeof(s8), &tmp);
1445 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1446 * @skb: socket buffer to add attribute to
1447 * @attrtype: attribute type
1448 * @value: numeric value
1450 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1454 return nla_put(skb, attrtype, sizeof(s16), &tmp);
1458 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1459 * @skb: socket buffer to add attribute to
1460 * @attrtype: attribute type
1461 * @value: numeric value
1463 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1467 return nla_put(skb, attrtype, sizeof(s32), &tmp);
1471 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1472 * @skb: socket buffer to add attribute to
1473 * @attrtype: attribute type
1474 * @value: numeric value
1475 * @padattr: attribute type for the padding
1477 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1482 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1486 * nla_put_string - Add a string netlink attribute to a socket buffer
1487 * @skb: socket buffer to add attribute to
1488 * @attrtype: attribute type
1489 * @str: NUL terminated string
1491 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1494 return nla_put(skb, attrtype, strlen(str) + 1, str);
1498 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1499 * @skb: socket buffer to add attribute to
1500 * @attrtype: attribute type
1502 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1504 return nla_put(skb, attrtype, 0, NULL);
1508 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1509 * @skb: socket buffer to add attribute to
1510 * @attrtype: attribute type
1511 * @njiffies: number of jiffies to convert to msecs
1512 * @padattr: attribute type for the padding
1514 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1515 unsigned long njiffies, int padattr)
1517 u64 tmp = jiffies_to_msecs(njiffies);
1519 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1523 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1525 * @skb: socket buffer to add attribute to
1526 * @attrtype: attribute type
1527 * @addr: IPv4 address
1529 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1534 return nla_put_be32(skb, attrtype, tmp);
1538 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1540 * @skb: socket buffer to add attribute to
1541 * @attrtype: attribute type
1542 * @addr: IPv6 address
1544 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1545 const struct in6_addr *addr)
1547 return nla_put(skb, attrtype, sizeof(*addr), addr);
1551 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1552 * @skb: socket buffer to add attribute to
1553 * @attrtype: attribute type
1554 * @value: value carrying bits
1555 * @selector: selector of valid bits
1557 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1558 __u32 value, __u32 selector)
1560 struct nla_bitfield32 tmp = { value, selector, };
1562 return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1566 * nla_get_u32 - return payload of u32 attribute
1567 * @nla: u32 netlink attribute
1569 static inline u32 nla_get_u32(const struct nlattr *nla)
1571 return *(u32 *) nla_data(nla);
1575 * nla_get_be32 - return payload of __be32 attribute
1576 * @nla: __be32 netlink attribute
1578 static inline __be32 nla_get_be32(const struct nlattr *nla)
1580 return *(__be32 *) nla_data(nla);
1584 * nla_get_le32 - return payload of __le32 attribute
1585 * @nla: __le32 netlink attribute
1587 static inline __le32 nla_get_le32(const struct nlattr *nla)
1589 return *(__le32 *) nla_data(nla);
1593 * nla_get_u16 - return payload of u16 attribute
1594 * @nla: u16 netlink attribute
1596 static inline u16 nla_get_u16(const struct nlattr *nla)
1598 return *(u16 *) nla_data(nla);
1602 * nla_get_be16 - return payload of __be16 attribute
1603 * @nla: __be16 netlink attribute
1605 static inline __be16 nla_get_be16(const struct nlattr *nla)
1607 return *(__be16 *) nla_data(nla);
1611 * nla_get_le16 - return payload of __le16 attribute
1612 * @nla: __le16 netlink attribute
1614 static inline __le16 nla_get_le16(const struct nlattr *nla)
1616 return *(__le16 *) nla_data(nla);
1620 * nla_get_u8 - return payload of u8 attribute
1621 * @nla: u8 netlink attribute
1623 static inline u8 nla_get_u8(const struct nlattr *nla)
1625 return *(u8 *) nla_data(nla);
1629 * nla_get_u64 - return payload of u64 attribute
1630 * @nla: u64 netlink attribute
1632 static inline u64 nla_get_u64(const struct nlattr *nla)
1636 nla_memcpy(&tmp, nla, sizeof(tmp));
1642 * nla_get_be64 - return payload of __be64 attribute
1643 * @nla: __be64 netlink attribute
1645 static inline __be64 nla_get_be64(const struct nlattr *nla)
1649 nla_memcpy(&tmp, nla, sizeof(tmp));
1655 * nla_get_le64 - return payload of __le64 attribute
1656 * @nla: __le64 netlink attribute
1658 static inline __le64 nla_get_le64(const struct nlattr *nla)
1660 return *(__le64 *) nla_data(nla);
1664 * nla_get_s32 - return payload of s32 attribute
1665 * @nla: s32 netlink attribute
1667 static inline s32 nla_get_s32(const struct nlattr *nla)
1669 return *(s32 *) nla_data(nla);
1673 * nla_get_s16 - return payload of s16 attribute
1674 * @nla: s16 netlink attribute
1676 static inline s16 nla_get_s16(const struct nlattr *nla)
1678 return *(s16 *) nla_data(nla);
1682 * nla_get_s8 - return payload of s8 attribute
1683 * @nla: s8 netlink attribute
1685 static inline s8 nla_get_s8(const struct nlattr *nla)
1687 return *(s8 *) nla_data(nla);
1691 * nla_get_s64 - return payload of s64 attribute
1692 * @nla: s64 netlink attribute
1694 static inline s64 nla_get_s64(const struct nlattr *nla)
1698 nla_memcpy(&tmp, nla, sizeof(tmp));
1704 * nla_get_flag - return payload of flag attribute
1705 * @nla: flag netlink attribute
1707 static inline int nla_get_flag(const struct nlattr *nla)
1713 * nla_get_msecs - return payload of msecs attribute
1714 * @nla: msecs netlink attribute
1716 * Returns the number of milliseconds in jiffies.
1718 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1720 u64 msecs = nla_get_u64(nla);
1722 return msecs_to_jiffies((unsigned long) msecs);
1726 * nla_get_in_addr - return payload of IPv4 address attribute
1727 * @nla: IPv4 address netlink attribute
1729 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1731 return *(__be32 *) nla_data(nla);
1735 * nla_get_in6_addr - return payload of IPv6 address attribute
1736 * @nla: IPv6 address netlink attribute
1738 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1740 struct in6_addr tmp;
1742 nla_memcpy(&tmp, nla, sizeof(tmp));
1747 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1748 * @nla: nla_bitfield32 attribute
1750 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1752 struct nla_bitfield32 tmp;
1754 nla_memcpy(&tmp, nla, sizeof(tmp));
1759 * nla_memdup - duplicate attribute memory (kmemdup)
1760 * @src: netlink attribute to duplicate from
1763 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1765 return kmemdup(nla_data(src), nla_len(src), gfp);
1769 * nla_nest_start_noflag - Start a new level of nested attributes
1770 * @skb: socket buffer to add attributes to
1771 * @attrtype: attribute type of container
1773 * This function exists for backward compatibility to use in APIs which never
1774 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1775 * nla_nest_start() which sets the flag.
1777 * Returns the container attribute or NULL on error
1779 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1782 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1784 if (nla_put(skb, attrtype, 0, NULL) < 0)
1791 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1792 * @skb: socket buffer to add attributes to
1793 * @attrtype: attribute type of container
1795 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1796 * flag. This is the preferred function to use in new code.
1798 * Returns the container attribute or NULL on error
1800 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1802 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1806 * nla_nest_end - Finalize nesting of attributes
1807 * @skb: socket buffer the attributes are stored in
1808 * @start: container attribute
1810 * Corrects the container attribute header to include the all
1811 * appeneded attributes.
1813 * Returns the total data length of the skb.
1815 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1817 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1822 * nla_nest_cancel - Cancel nesting of attributes
1823 * @skb: socket buffer the message is stored in
1824 * @start: container attribute
1826 * Removes the container attribute and including all nested
1827 * attributes. Returns -EMSGSIZE
1829 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1831 nlmsg_trim(skb, start);
1835 * __nla_validate_nested - Validate a stream of nested attributes
1836 * @start: container attribute
1837 * @maxtype: maximum attribute type to be expected
1838 * @policy: validation policy
1839 * @validate: validation strictness
1840 * @extack: extended ACK report struct
1842 * Validates all attributes in the nested attribute stream against the
1843 * specified policy. Attributes with a type exceeding maxtype will be
1844 * ignored. See documenation of struct nla_policy for more details.
1846 * Returns 0 on success or a negative error code.
1848 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1849 const struct nla_policy *policy,
1850 unsigned int validate,
1851 struct netlink_ext_ack *extack)
1853 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1858 nla_validate_nested(const struct nlattr *start, int maxtype,
1859 const struct nla_policy *policy,
1860 struct netlink_ext_ack *extack)
1862 return __nla_validate_nested(start, maxtype, policy,
1863 NL_VALIDATE_STRICT, extack);
1867 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1868 const struct nla_policy *policy,
1869 struct netlink_ext_ack *extack)
1871 return __nla_validate_nested(start, maxtype, policy,
1872 NL_VALIDATE_LIBERAL, extack);
1876 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1877 * @skb: socket buffer the message is stored in
1879 * Return true if padding is needed to align the next attribute (nla_data()) to
1880 * a 64-bit aligned area.
1882 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1884 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1885 /* The nlattr header is 4 bytes in size, that's why we test
1886 * if the skb->data _is_ aligned. A NOP attribute, plus
1887 * nlattr header for next attribute, will make nla_data()
1890 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1897 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1898 * @skb: socket buffer the message is stored in
1899 * @padattr: attribute type for the padding
1901 * Conditionally emit a padding netlink attribute in order to make
1902 * the next attribute we emit have a 64-bit aligned nla_data() area.
1903 * This will only be done in architectures which do not have
1904 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1906 * Returns zero on success or a negative error code.
1908 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1910 if (nla_need_padding_for_64bit(skb) &&
1911 !nla_reserve(skb, padattr, 0))
1918 * nla_total_size_64bit - total length of attribute including padding
1919 * @payload: length of payload
1921 static inline int nla_total_size_64bit(int payload)
1923 return NLA_ALIGN(nla_attr_size(payload))
1924 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1925 + NLA_ALIGN(nla_attr_size(0))
1931 * nla_for_each_attr - iterate over a stream of attributes
1932 * @pos: loop counter, set to current attribute
1933 * @head: head of attribute stream
1934 * @len: length of attribute stream
1935 * @rem: initialized to len, holds bytes currently remaining in stream
1937 #define nla_for_each_attr(pos, head, len, rem) \
1938 for (pos = head, rem = len; \
1940 pos = nla_next(pos, &(rem)))
1943 * nla_for_each_nested - iterate over nested attributes
1944 * @pos: loop counter, set to current attribute
1945 * @nla: attribute containing the nested attributes
1946 * @rem: initialized to len, holds bytes currently remaining in stream
1948 #define nla_for_each_nested(pos, nla, rem) \
1949 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1952 * nla_is_last - Test if attribute is last in stream
1953 * @nla: attribute to test
1954 * @rem: bytes remaining in stream
1956 static inline bool nla_is_last(const struct nlattr *nla, int rem)
1958 return nla->nla_len == rem;
1961 void nla_get_range_unsigned(const struct nla_policy *pt,
1962 struct netlink_range_validation *range);
1963 void nla_get_range_signed(const struct nla_policy *pt,
1964 struct netlink_range_validation_signed *range);
1966 struct netlink_policy_dump_state;
1968 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
1969 const struct nla_policy *policy,
1970 unsigned int maxtype);
1971 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
1972 const struct nla_policy *policy,
1973 unsigned int maxtype);
1974 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
1975 int netlink_policy_dump_write(struct sk_buff *skb,
1976 struct netlink_policy_dump_state *state);
1977 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
1978 int netlink_policy_dump_write_attr(struct sk_buff *skb,
1979 const struct nla_policy *pt,
1981 void netlink_policy_dump_free(struct netlink_policy_dump_state *state);