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
187 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
189 struct netlink_range_validation {
193 struct netlink_range_validation_signed {
197 enum nla_policy_validation {
200 NLA_VALIDATE_RANGE_WARN_TOO_LONG,
204 NLA_VALIDATE_RANGE_PTR,
205 NLA_VALIDATE_FUNCTION,
209 * struct nla_policy - attribute validation policy
210 * @type: Type of attribute or NLA_UNSPEC
211 * @validation_type: type of attribute validation done in addition to
212 * type-specific validation (e.g. range, function call), see
213 * &enum nla_policy_validation
214 * @len: Type specific length of payload
216 * Policies are defined as arrays of this struct, the array must be
217 * accessible by attribute type up to the highest identifier to be expected.
219 * Meaning of `len' field:
220 * NLA_STRING Maximum length of string
221 * NLA_NUL_STRING Maximum length of string (excluding NUL)
223 * NLA_BINARY Maximum length of attribute payload
224 * (but see also below with the validation type)
226 * NLA_NESTED_ARRAY Length verification is done by checking len of
227 * nested header (or empty); len field is used if
228 * nested_policy is also used, for the max attr
229 * number in the nested policy.
234 * NLA_MSECS Leaving the length field zero will verify the
235 * given type fits, using it verifies minimum length
236 * just like "All other"
237 * NLA_BITFIELD32 Unused
239 * All other Minimum length of attribute payload
241 * Meaning of validation union:
242 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and
243 * `bitfield32_valid' is the u32 value of valid flags
244 * NLA_REJECT This attribute is always rejected and `reject_message'
245 * may point to a string to report as the error instead
246 * of the generic one in extended ACK.
247 * NLA_NESTED `nested_policy' to a nested policy to validate, must
248 * also set `len' to the max attribute number. Use the
249 * provided NLA_POLICY_NESTED() macro.
250 * Note that nla_parse() will validate, but of course not
251 * parse, the nested sub-policies.
252 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate,
253 * must also set `len' to the max attribute number. Use
254 * the provided NLA_POLICY_NESTED_ARRAY() macro.
255 * The difference to NLA_NESTED is the structure:
256 * NLA_NESTED has the nested attributes directly inside
257 * while an array has the nested attributes at another
258 * level down and the attribute types directly in the
259 * nesting don't matter.
267 * NLA_S64 The `min' and `max' fields are used depending on the
268 * validation_type field, if that is min/max/range then
269 * the min, max or both are used (respectively) to check
270 * the value of the integer attribute.
271 * Note that in the interest of code simplicity and
272 * struct size both limits are s16, so you cannot
273 * enforce a range that doesn't fall within the range
274 * of s16 - do that as usual in the code instead.
275 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
276 * NLA_POLICY_RANGE() macros.
280 * NLA_U64 If the validation_type field instead is set to
281 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
282 * to a struct netlink_range_validation that indicates
283 * the min/max values.
284 * Use NLA_POLICY_FULL_RANGE().
288 * NLA_S64 If the validation_type field instead is set to
289 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
290 * pointer to a struct netlink_range_validation_signed
291 * that indicates the min/max values.
292 * Use NLA_POLICY_FULL_RANGE_SIGNED().
294 * NLA_BINARY If the validation type is like the ones for integers
295 * above, then the min/max length (not value like for
296 * integers) of the attribute is enforced.
298 * All other Unused - but note that it's a union
300 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
301 * NLA_BINARY Validation function called for the attribute.
302 * All other Unused - but note that it's a union
306 * static const u32 myvalidflags = 0xff231023;
308 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
309 * [ATTR_FOO] = { .type = NLA_U16 },
310 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
311 * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)),
312 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
320 const u32 bitfield32_valid;
322 const char *reject_message;
323 const struct nla_policy *nested_policy;
324 struct netlink_range_validation *range;
325 struct netlink_range_validation_signed *range_signed;
328 u8 network_byte_order:1;
330 int (*validate)(const struct nlattr *attr,
331 struct netlink_ext_ack *extack);
332 /* This entry is special, and used for the attribute at index 0
333 * only, and specifies special data about the policy, namely it
334 * specifies the "boundary type" where strict length validation
335 * starts for any attribute types >= this value, also, strict
336 * nesting validation starts here.
338 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
339 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to
340 * get the previous pure { .len = xyz } behaviour. The advantage
341 * of this is that types not specified in the policy will be
344 * For completely new families it should be set to 1 so that the
345 * validation is enforced for all attributes. For existing ones
346 * it should be set at least when new attributes are added to
347 * the enum used by the policy, and be set to the new value that
348 * was added to enforce strict validation from thereon.
350 u16 strict_start_type;
354 #define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN)
355 #define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
357 #define _NLA_POLICY_NESTED(maxattr, policy) \
358 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
359 #define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
360 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
361 #define NLA_POLICY_NESTED(policy) \
362 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
363 #define NLA_POLICY_NESTED_ARRAY(policy) \
364 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
365 #define NLA_POLICY_BITFIELD32(valid) \
366 { .type = NLA_BITFIELD32, .bitfield32_valid = valid }
368 #define __NLA_IS_UINT_TYPE(tp) \
369 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || tp == NLA_U64)
370 #define __NLA_IS_SINT_TYPE(tp) \
371 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64)
373 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
374 #define NLA_ENSURE_UINT_TYPE(tp) \
375 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
376 #define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \
377 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
379 tp == NLA_BINARY) + tp)
380 #define NLA_ENSURE_SINT_TYPE(tp) \
381 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
382 #define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \
383 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
384 __NLA_IS_SINT_TYPE(tp) || \
386 tp == NLA_BINARY) + tp)
387 #define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
388 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \
389 tp != NLA_REJECT && \
390 tp != NLA_NESTED && \
391 tp != NLA_NESTED_ARRAY) + tp)
393 #define NLA_POLICY_RANGE(tp, _min, _max) { \
394 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
395 .validation_type = NLA_VALIDATE_RANGE, \
400 #define NLA_POLICY_FULL_RANGE(tp, _range) { \
401 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \
402 .validation_type = NLA_VALIDATE_RANGE_PTR, \
406 #define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \
407 .type = NLA_ENSURE_SINT_TYPE(tp), \
408 .validation_type = NLA_VALIDATE_RANGE_PTR, \
409 .range_signed = _range, \
412 #define NLA_POLICY_MIN(tp, _min) { \
413 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
414 .validation_type = NLA_VALIDATE_MIN, \
418 #define NLA_POLICY_MAX(tp, _max) { \
419 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
420 .validation_type = NLA_VALIDATE_MAX, \
422 .network_byte_order = 0, \
425 #define NLA_POLICY_MAX_BE(tp, _max) { \
426 .type = NLA_ENSURE_UINT_TYPE(tp), \
427 .validation_type = NLA_VALIDATE_MAX, \
429 .network_byte_order = 1, \
432 #define NLA_POLICY_MASK(tp, _mask) { \
433 .type = NLA_ENSURE_UINT_TYPE(tp), \
434 .validation_type = NLA_VALIDATE_MASK, \
438 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \
439 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \
440 .validation_type = NLA_VALIDATE_FUNCTION, \
442 .len = __VA_ARGS__ + 0, \
445 #define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
446 #define NLA_POLICY_EXACT_LEN_WARN(_len) { \
447 .type = NLA_BINARY, \
448 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \
452 #define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len)
455 * struct nl_info - netlink source information
456 * @nlh: Netlink message header of original request
457 * @nl_net: Network namespace
458 * @portid: Netlink PORTID of requesting application
459 * @skip_notify: Skip netlink notifications to user space
460 * @skip_notify_kernel: Skip selected in-kernel notifications
463 struct nlmsghdr *nlh;
467 skip_notify_kernel:1;
471 * enum netlink_validation - netlink message/attribute validation levels
472 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
473 * extra data at the end of the message, attributes being longer than
474 * they should be, or unknown attributes being present.
475 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
476 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
477 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
478 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
479 * This can safely be set by the kernel when the given policy has no
480 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
481 * are enforced going forward.
482 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
483 * U8, U16, U32 must have exact size, etc.)
484 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
485 * and unset for other policies.
487 enum netlink_validation {
488 NL_VALIDATE_LIBERAL = 0,
489 NL_VALIDATE_TRAILING = BIT(0),
490 NL_VALIDATE_MAXTYPE = BIT(1),
491 NL_VALIDATE_UNSPEC = BIT(2),
492 NL_VALIDATE_STRICT_ATTRS = BIT(3),
493 NL_VALIDATE_NESTED = BIT(4),
496 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
498 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
499 NL_VALIDATE_MAXTYPE |\
500 NL_VALIDATE_UNSPEC |\
501 NL_VALIDATE_STRICT_ATTRS |\
504 int netlink_rcv_skb(struct sk_buff *skb,
505 int (*cb)(struct sk_buff *, struct nlmsghdr *,
506 struct netlink_ext_ack *));
507 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
508 unsigned int group, int report, gfp_t flags);
510 int __nla_validate(const struct nlattr *head, int len, int maxtype,
511 const struct nla_policy *policy, unsigned int validate,
512 struct netlink_ext_ack *extack);
513 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
514 int len, const struct nla_policy *policy, unsigned int validate,
515 struct netlink_ext_ack *extack);
516 int nla_policy_len(const struct nla_policy *, int);
517 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
518 ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
519 char *nla_strdup(const struct nlattr *nla, gfp_t flags);
520 int nla_memcpy(void *dest, const struct nlattr *src, int count);
521 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
522 int nla_strcmp(const struct nlattr *nla, const char *str);
523 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
524 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
525 int attrlen, int padattr);
526 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
527 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
528 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
529 int attrlen, int padattr);
530 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
531 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
533 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
534 const void *data, int padattr);
535 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
536 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
537 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
538 const void *data, int padattr);
539 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
540 int nla_append(struct sk_buff *skb, int attrlen, const void *data);
542 /**************************************************************************
544 **************************************************************************/
547 * nlmsg_msg_size - length of netlink message not including padding
548 * @payload: length of message payload
550 static inline int nlmsg_msg_size(int payload)
552 return NLMSG_HDRLEN + payload;
556 * nlmsg_total_size - length of netlink message including padding
557 * @payload: length of message payload
559 static inline int nlmsg_total_size(int payload)
561 return NLMSG_ALIGN(nlmsg_msg_size(payload));
565 * nlmsg_padlen - length of padding at the message's tail
566 * @payload: length of message payload
568 static inline int nlmsg_padlen(int payload)
570 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
574 * nlmsg_data - head of message payload
575 * @nlh: netlink message header
577 static inline void *nlmsg_data(const struct nlmsghdr *nlh)
579 return (unsigned char *) nlh + NLMSG_HDRLEN;
583 * nlmsg_len - length of message payload
584 * @nlh: netlink message header
586 static inline int nlmsg_len(const struct nlmsghdr *nlh)
588 return nlh->nlmsg_len - NLMSG_HDRLEN;
592 * nlmsg_attrdata - head of attributes data
593 * @nlh: netlink message header
594 * @hdrlen: length of family specific header
596 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
599 unsigned char *data = nlmsg_data(nlh);
600 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
604 * nlmsg_attrlen - length of attributes data
605 * @nlh: netlink message header
606 * @hdrlen: length of family specific header
608 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
610 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
614 * nlmsg_ok - check if the netlink message fits into the remaining bytes
615 * @nlh: netlink message header
616 * @remaining: number of bytes remaining in message stream
618 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
620 return (remaining >= (int) sizeof(struct nlmsghdr) &&
621 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
622 nlh->nlmsg_len <= remaining);
626 * nlmsg_next - next netlink message in message stream
627 * @nlh: netlink message header
628 * @remaining: number of bytes remaining in message stream
630 * Returns the next netlink message in the message stream and
631 * decrements remaining by the size of the current message.
633 static inline struct nlmsghdr *
634 nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
636 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
638 *remaining -= totlen;
640 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
644 * nla_parse - Parse a stream of attributes into a tb buffer
645 * @tb: destination array with maxtype+1 elements
646 * @maxtype: maximum attribute type to be expected
647 * @head: head of attribute stream
648 * @len: length of attribute stream
649 * @policy: validation policy
650 * @extack: extended ACK pointer
652 * Parses a stream of attributes and stores a pointer to each attribute in
653 * the tb array accessible via the attribute type. Attributes with a type
654 * exceeding maxtype will be rejected, policy must be specified, attributes
655 * will be validated in the strictest way possible.
657 * Returns 0 on success or a negative error code.
659 static inline int nla_parse(struct nlattr **tb, int maxtype,
660 const struct nlattr *head, int len,
661 const struct nla_policy *policy,
662 struct netlink_ext_ack *extack)
664 return __nla_parse(tb, maxtype, head, len, policy,
665 NL_VALIDATE_STRICT, extack);
669 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
670 * @tb: destination array with maxtype+1 elements
671 * @maxtype: maximum attribute type to be expected
672 * @head: head of attribute stream
673 * @len: length of attribute stream
674 * @policy: validation policy
675 * @extack: extended ACK pointer
677 * Parses a stream of attributes and stores a pointer to each attribute in
678 * the tb array accessible via the attribute type. Attributes with a type
679 * exceeding maxtype will be ignored and attributes from the policy are not
680 * always strictly validated (only for new attributes).
682 * Returns 0 on success or a negative error code.
684 static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
685 const struct nlattr *head, int len,
686 const struct nla_policy *policy,
687 struct netlink_ext_ack *extack)
689 return __nla_parse(tb, maxtype, head, len, policy,
690 NL_VALIDATE_LIBERAL, extack);
694 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
695 * @tb: destination array with maxtype+1 elements
696 * @maxtype: maximum attribute type to be expected
697 * @head: head of attribute stream
698 * @len: length of attribute stream
699 * @policy: validation policy
700 * @extack: extended ACK pointer
702 * Parses a stream of attributes and stores a pointer to each attribute in
703 * the tb array accessible via the attribute type. Attributes with a type
704 * exceeding maxtype will be rejected as well as trailing data, but the
705 * policy is not completely strictly validated (only for new attributes).
707 * Returns 0 on success or a negative error code.
709 static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
710 const struct nlattr *head,
712 const struct nla_policy *policy,
713 struct netlink_ext_ack *extack)
715 return __nla_parse(tb, maxtype, head, len, policy,
716 NL_VALIDATE_DEPRECATED_STRICT, extack);
720 * __nlmsg_parse - parse attributes of a netlink message
721 * @nlh: netlink message header
722 * @hdrlen: length of family specific header
723 * @tb: destination array with maxtype+1 elements
724 * @maxtype: maximum attribute type to be expected
725 * @policy: validation policy
726 * @validate: validation strictness
727 * @extack: extended ACK report struct
731 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
732 struct nlattr *tb[], int maxtype,
733 const struct nla_policy *policy,
734 unsigned int validate,
735 struct netlink_ext_ack *extack)
737 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
738 NL_SET_ERR_MSG(extack, "Invalid header length");
742 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
743 nlmsg_attrlen(nlh, hdrlen), policy, validate,
748 * nlmsg_parse - parse attributes of a netlink message
749 * @nlh: netlink message header
750 * @hdrlen: length of family specific header
751 * @tb: destination array with maxtype+1 elements
752 * @maxtype: maximum attribute type to be expected
753 * @policy: validation policy
754 * @extack: extended ACK report struct
758 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
759 struct nlattr *tb[], int maxtype,
760 const struct nla_policy *policy,
761 struct netlink_ext_ack *extack)
763 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
764 NL_VALIDATE_STRICT, extack);
768 * nlmsg_parse_deprecated - parse attributes of a netlink message
769 * @nlh: netlink message header
770 * @hdrlen: length of family specific header
771 * @tb: destination array with maxtype+1 elements
772 * @maxtype: maximum attribute type to be expected
773 * @policy: validation policy
774 * @extack: extended ACK report struct
776 * See nla_parse_deprecated()
778 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
779 struct nlattr *tb[], int maxtype,
780 const struct nla_policy *policy,
781 struct netlink_ext_ack *extack)
783 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
784 NL_VALIDATE_LIBERAL, extack);
788 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
789 * @nlh: netlink message header
790 * @hdrlen: length of family specific header
791 * @tb: destination array with maxtype+1 elements
792 * @maxtype: maximum attribute type to be expected
793 * @policy: validation policy
794 * @extack: extended ACK report struct
796 * See nla_parse_deprecated_strict()
799 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
800 struct nlattr *tb[], int maxtype,
801 const struct nla_policy *policy,
802 struct netlink_ext_ack *extack)
804 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
805 NL_VALIDATE_DEPRECATED_STRICT, extack);
809 * nlmsg_find_attr - find a specific attribute in a netlink message
810 * @nlh: netlink message header
811 * @hdrlen: length of familiy specific header
812 * @attrtype: type of attribute to look for
814 * Returns the first attribute which matches the specified type.
816 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
817 int hdrlen, int attrtype)
819 return nla_find(nlmsg_attrdata(nlh, hdrlen),
820 nlmsg_attrlen(nlh, hdrlen), attrtype);
824 * nla_validate_deprecated - Validate a stream of attributes
825 * @head: head of attribute stream
826 * @len: length of attribute stream
827 * @maxtype: maximum attribute type to be expected
828 * @policy: validation policy
829 * @extack: extended ACK report struct
831 * Validates all attributes in the specified attribute stream against the
832 * specified policy. Validation is done in liberal mode.
833 * See documenation of struct nla_policy for more details.
835 * Returns 0 on success or a negative error code.
837 static inline int nla_validate_deprecated(const struct nlattr *head, int len,
839 const struct nla_policy *policy,
840 struct netlink_ext_ack *extack)
842 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
847 * nla_validate - Validate a stream of attributes
848 * @head: head of attribute stream
849 * @len: length of attribute stream
850 * @maxtype: maximum attribute type to be expected
851 * @policy: validation policy
852 * @extack: extended ACK report struct
854 * Validates all attributes in the specified attribute stream against the
855 * specified policy. Validation is done in strict mode.
856 * See documenation of struct nla_policy for more details.
858 * Returns 0 on success or a negative error code.
860 static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
861 const struct nla_policy *policy,
862 struct netlink_ext_ack *extack)
864 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
869 * nlmsg_validate_deprecated - validate a netlink message including attributes
870 * @nlh: netlinket message header
871 * @hdrlen: length of familiy specific header
872 * @maxtype: maximum attribute type to be expected
873 * @policy: validation policy
874 * @extack: extended ACK report struct
876 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
877 int hdrlen, int maxtype,
878 const struct nla_policy *policy,
879 struct netlink_ext_ack *extack)
881 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
884 return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
885 nlmsg_attrlen(nlh, hdrlen), maxtype,
886 policy, NL_VALIDATE_LIBERAL, extack);
892 * nlmsg_report - need to report back to application?
893 * @nlh: netlink message header
895 * Returns 1 if a report back to the application is requested.
897 static inline int nlmsg_report(const struct nlmsghdr *nlh)
899 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
903 * nlmsg_for_each_attr - iterate over a stream of attributes
904 * @pos: loop counter, set to current attribute
905 * @nlh: netlink message header
906 * @hdrlen: length of familiy specific header
907 * @rem: initialized to len, holds bytes currently remaining in stream
909 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
910 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
911 nlmsg_attrlen(nlh, hdrlen), rem)
914 * nlmsg_put - Add a new netlink message to an skb
915 * @skb: socket buffer to store message in
916 * @portid: netlink PORTID of requesting application
917 * @seq: sequence number of message
918 * @type: message type
919 * @payload: length of message payload
920 * @flags: message flags
922 * Returns NULL if the tailroom of the skb is insufficient to store
923 * the message header and payload.
925 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
926 int type, int payload, int flags)
928 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
931 return __nlmsg_put(skb, portid, seq, type, payload, flags);
935 * nlmsg_put_answer - Add a new callback based netlink message to an skb
936 * @skb: socket buffer to store message in
937 * @cb: netlink callback
938 * @type: message type
939 * @payload: length of message payload
940 * @flags: message flags
942 * Returns NULL if the tailroom of the skb is insufficient to store
943 * the message header and payload.
945 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
946 struct netlink_callback *cb,
947 int type, int payload,
950 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
951 type, payload, flags);
955 * nlmsg_new - Allocate a new netlink message
956 * @payload: size of the message payload
957 * @flags: the type of memory to allocate.
959 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
960 * and a good default is needed.
962 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
964 return alloc_skb(nlmsg_total_size(payload), flags);
968 * nlmsg_end - Finalize a netlink message
969 * @skb: socket buffer the message is stored in
970 * @nlh: netlink message header
972 * Corrects the netlink message header to include the appeneded
973 * attributes. Only necessary if attributes have been added to
976 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
978 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
982 * nlmsg_get_pos - return current position in netlink message
983 * @skb: socket buffer the message is stored in
985 * Returns a pointer to the current tail of the message.
987 static inline void *nlmsg_get_pos(struct sk_buff *skb)
989 return skb_tail_pointer(skb);
993 * nlmsg_trim - Trim message to a mark
994 * @skb: socket buffer the message is stored in
995 * @mark: mark to trim to
997 * Trims the message to the provided mark.
999 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1002 WARN_ON((unsigned char *) mark < skb->data);
1003 skb_trim(skb, (unsigned char *) mark - skb->data);
1008 * nlmsg_cancel - Cancel construction of a netlink message
1009 * @skb: socket buffer the message is stored in
1010 * @nlh: netlink message header
1012 * Removes the complete netlink message including all
1013 * attributes from the socket buffer again.
1015 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1017 nlmsg_trim(skb, nlh);
1021 * nlmsg_free - free a netlink message
1022 * @skb: socket buffer of netlink message
1024 static inline void nlmsg_free(struct sk_buff *skb)
1030 * nlmsg_multicast - multicast a netlink message
1031 * @sk: netlink socket to spread messages to
1032 * @skb: netlink message as socket buffer
1033 * @portid: own netlink portid to avoid sending to yourself
1034 * @group: multicast group id
1035 * @flags: allocation flags
1037 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1038 u32 portid, unsigned int group, gfp_t flags)
1042 NETLINK_CB(skb).dst_group = group;
1044 err = netlink_broadcast(sk, skb, portid, group, flags);
1052 * nlmsg_unicast - unicast a netlink message
1053 * @sk: netlink socket to spread message to
1054 * @skb: netlink message as socket buffer
1055 * @portid: netlink portid of the destination socket
1057 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1061 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1069 * nlmsg_for_each_msg - iterate over a stream of messages
1070 * @pos: loop counter, set to current message
1071 * @head: head of message stream
1072 * @len: length of message stream
1073 * @rem: initialized to len, holds bytes currently remaining in stream
1075 #define nlmsg_for_each_msg(pos, head, len, rem) \
1076 for (pos = head, rem = len; \
1077 nlmsg_ok(pos, rem); \
1078 pos = nlmsg_next(pos, &(rem)))
1081 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1082 * @cb: netlink callback structure that stores the sequence number
1083 * @nlh: netlink message header to write the flag to
1085 * This function checks if the sequence (generation) number changed during dump
1086 * and if it did, advertises it in the netlink message header.
1088 * The correct way to use it is to set cb->seq to the generation counter when
1089 * all locks for dumping have been acquired, and then call this function for
1090 * each message that is generated.
1092 * Note that due to initialisation concerns, 0 is an invalid sequence number
1093 * and must not be used by code that uses this functionality.
1096 nl_dump_check_consistent(struct netlink_callback *cb,
1097 struct nlmsghdr *nlh)
1099 if (cb->prev_seq && cb->seq != cb->prev_seq)
1100 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1101 cb->prev_seq = cb->seq;
1104 /**************************************************************************
1105 * Netlink Attributes
1106 **************************************************************************/
1109 * nla_attr_size - length of attribute not including padding
1110 * @payload: length of payload
1112 static inline int nla_attr_size(int payload)
1114 return NLA_HDRLEN + payload;
1118 * nla_total_size - total length of attribute including padding
1119 * @payload: length of payload
1121 static inline int nla_total_size(int payload)
1123 return NLA_ALIGN(nla_attr_size(payload));
1127 * nla_padlen - length of padding at the tail of attribute
1128 * @payload: length of payload
1130 static inline int nla_padlen(int payload)
1132 return nla_total_size(payload) - nla_attr_size(payload);
1136 * nla_type - attribute type
1137 * @nla: netlink attribute
1139 static inline int nla_type(const struct nlattr *nla)
1141 return nla->nla_type & NLA_TYPE_MASK;
1145 * nla_data - head of payload
1146 * @nla: netlink attribute
1148 static inline void *nla_data(const struct nlattr *nla)
1150 return (char *) nla + NLA_HDRLEN;
1154 * nla_len - length of payload
1155 * @nla: netlink attribute
1157 static inline int nla_len(const struct nlattr *nla)
1159 return nla->nla_len - NLA_HDRLEN;
1163 * nla_ok - check if the netlink attribute fits into the remaining bytes
1164 * @nla: netlink attribute
1165 * @remaining: number of bytes remaining in attribute stream
1167 static inline int nla_ok(const struct nlattr *nla, int remaining)
1169 return remaining >= (int) sizeof(*nla) &&
1170 nla->nla_len >= sizeof(*nla) &&
1171 nla->nla_len <= remaining;
1175 * nla_next - next netlink attribute in attribute stream
1176 * @nla: netlink attribute
1177 * @remaining: number of bytes remaining in attribute stream
1179 * Returns the next netlink attribute in the attribute stream and
1180 * decrements remaining by the size of the current attribute.
1182 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1184 unsigned int totlen = NLA_ALIGN(nla->nla_len);
1186 *remaining -= totlen;
1187 return (struct nlattr *) ((char *) nla + totlen);
1191 * nla_find_nested - find attribute in a set of nested attributes
1192 * @nla: attribute containing the nested attributes
1193 * @attrtype: type of attribute to look for
1195 * Returns the first attribute which matches the specified type.
1197 static inline struct nlattr *
1198 nla_find_nested(const struct nlattr *nla, int attrtype)
1200 return nla_find(nla_data(nla), nla_len(nla), attrtype);
1204 * nla_parse_nested - parse nested attributes
1205 * @tb: destination array with maxtype+1 elements
1206 * @maxtype: maximum attribute type to be expected
1207 * @nla: attribute containing the nested attributes
1208 * @policy: validation policy
1209 * @extack: extended ACK report struct
1213 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1214 const struct nlattr *nla,
1215 const struct nla_policy *policy,
1216 struct netlink_ext_ack *extack)
1218 if (!(nla->nla_type & NLA_F_NESTED)) {
1219 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1223 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1224 NL_VALIDATE_STRICT, extack);
1228 * nla_parse_nested_deprecated - parse nested attributes
1229 * @tb: destination array with maxtype+1 elements
1230 * @maxtype: maximum attribute type to be expected
1231 * @nla: attribute containing the nested attributes
1232 * @policy: validation policy
1233 * @extack: extended ACK report struct
1235 * See nla_parse_deprecated()
1237 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1238 const struct nlattr *nla,
1239 const struct nla_policy *policy,
1240 struct netlink_ext_ack *extack)
1242 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1243 NL_VALIDATE_LIBERAL, extack);
1247 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1248 * @skb: socket buffer to add attribute to
1249 * @attrtype: attribute type
1250 * @value: numeric value
1252 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1254 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
1257 return nla_put(skb, attrtype, sizeof(u8), &tmp);
1261 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1262 * @skb: socket buffer to add attribute to
1263 * @attrtype: attribute type
1264 * @value: numeric value
1266 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1270 return nla_put(skb, attrtype, sizeof(u16), &tmp);
1274 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1275 * @skb: socket buffer to add attribute to
1276 * @attrtype: attribute type
1277 * @value: numeric value
1279 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1283 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1287 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1288 * @skb: socket buffer to add attribute to
1289 * @attrtype: attribute type
1290 * @value: numeric value
1292 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1296 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1300 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1301 * @skb: socket buffer to add attribute to
1302 * @attrtype: attribute type
1303 * @value: numeric value
1305 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1309 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1313 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1314 * @skb: socket buffer to add attribute to
1315 * @attrtype: attribute type
1316 * @value: numeric value
1318 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1322 return nla_put(skb, attrtype, sizeof(u32), &tmp);
1326 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1327 * @skb: socket buffer to add attribute to
1328 * @attrtype: attribute type
1329 * @value: numeric value
1331 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1335 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1339 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1340 * @skb: socket buffer to add attribute to
1341 * @attrtype: attribute type
1342 * @value: numeric value
1344 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1348 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1352 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1353 * @skb: socket buffer to add attribute to
1354 * @attrtype: attribute type
1355 * @value: numeric value
1357 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1361 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1365 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1366 * @skb: socket buffer to add attribute to
1367 * @attrtype: attribute type
1368 * @value: numeric value
1369 * @padattr: attribute type for the padding
1371 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1372 u64 value, int padattr)
1376 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1380 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1381 * @skb: socket buffer to add attribute to
1382 * @attrtype: attribute type
1383 * @value: numeric value
1384 * @padattr: attribute type for the padding
1386 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1391 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1395 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1396 * @skb: socket buffer to add attribute to
1397 * @attrtype: attribute type
1398 * @value: numeric value
1399 * @padattr: attribute type for the padding
1401 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1406 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1411 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1412 * @skb: socket buffer to add attribute to
1413 * @attrtype: attribute type
1414 * @value: numeric value
1415 * @padattr: attribute type for the padding
1417 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1422 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1426 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1427 * @skb: socket buffer to add attribute to
1428 * @attrtype: attribute type
1429 * @value: numeric value
1431 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1435 return nla_put(skb, attrtype, sizeof(s8), &tmp);
1439 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1440 * @skb: socket buffer to add attribute to
1441 * @attrtype: attribute type
1442 * @value: numeric value
1444 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1448 return nla_put(skb, attrtype, sizeof(s16), &tmp);
1452 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1453 * @skb: socket buffer to add attribute to
1454 * @attrtype: attribute type
1455 * @value: numeric value
1457 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1461 return nla_put(skb, attrtype, sizeof(s32), &tmp);
1465 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1466 * @skb: socket buffer to add attribute to
1467 * @attrtype: attribute type
1468 * @value: numeric value
1469 * @padattr: attribute type for the padding
1471 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1476 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1480 * nla_put_string - Add a string netlink attribute to a socket buffer
1481 * @skb: socket buffer to add attribute to
1482 * @attrtype: attribute type
1483 * @str: NUL terminated string
1485 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1488 return nla_put(skb, attrtype, strlen(str) + 1, str);
1492 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1493 * @skb: socket buffer to add attribute to
1494 * @attrtype: attribute type
1496 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1498 return nla_put(skb, attrtype, 0, NULL);
1502 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1503 * @skb: socket buffer to add attribute to
1504 * @attrtype: attribute type
1505 * @njiffies: number of jiffies to convert to msecs
1506 * @padattr: attribute type for the padding
1508 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1509 unsigned long njiffies, int padattr)
1511 u64 tmp = jiffies_to_msecs(njiffies);
1513 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1517 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1519 * @skb: socket buffer to add attribute to
1520 * @attrtype: attribute type
1521 * @addr: IPv4 address
1523 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1528 return nla_put_be32(skb, attrtype, tmp);
1532 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1534 * @skb: socket buffer to add attribute to
1535 * @attrtype: attribute type
1536 * @addr: IPv6 address
1538 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1539 const struct in6_addr *addr)
1541 return nla_put(skb, attrtype, sizeof(*addr), addr);
1545 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1546 * @skb: socket buffer to add attribute to
1547 * @attrtype: attribute type
1548 * @value: value carrying bits
1549 * @selector: selector of valid bits
1551 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1552 __u32 value, __u32 selector)
1554 struct nla_bitfield32 tmp = { value, selector, };
1556 return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1560 * nla_get_u32 - return payload of u32 attribute
1561 * @nla: u32 netlink attribute
1563 static inline u32 nla_get_u32(const struct nlattr *nla)
1565 return *(u32 *) nla_data(nla);
1569 * nla_get_be32 - return payload of __be32 attribute
1570 * @nla: __be32 netlink attribute
1572 static inline __be32 nla_get_be32(const struct nlattr *nla)
1574 return *(__be32 *) nla_data(nla);
1578 * nla_get_le32 - return payload of __le32 attribute
1579 * @nla: __le32 netlink attribute
1581 static inline __le32 nla_get_le32(const struct nlattr *nla)
1583 return *(__le32 *) nla_data(nla);
1587 * nla_get_u16 - return payload of u16 attribute
1588 * @nla: u16 netlink attribute
1590 static inline u16 nla_get_u16(const struct nlattr *nla)
1592 return *(u16 *) nla_data(nla);
1596 * nla_get_be16 - return payload of __be16 attribute
1597 * @nla: __be16 netlink attribute
1599 static inline __be16 nla_get_be16(const struct nlattr *nla)
1601 return *(__be16 *) nla_data(nla);
1605 * nla_get_le16 - return payload of __le16 attribute
1606 * @nla: __le16 netlink attribute
1608 static inline __le16 nla_get_le16(const struct nlattr *nla)
1610 return *(__le16 *) nla_data(nla);
1614 * nla_get_u8 - return payload of u8 attribute
1615 * @nla: u8 netlink attribute
1617 static inline u8 nla_get_u8(const struct nlattr *nla)
1619 return *(u8 *) nla_data(nla);
1623 * nla_get_u64 - return payload of u64 attribute
1624 * @nla: u64 netlink attribute
1626 static inline u64 nla_get_u64(const struct nlattr *nla)
1630 nla_memcpy(&tmp, nla, sizeof(tmp));
1636 * nla_get_be64 - return payload of __be64 attribute
1637 * @nla: __be64 netlink attribute
1639 static inline __be64 nla_get_be64(const struct nlattr *nla)
1643 nla_memcpy(&tmp, nla, sizeof(tmp));
1649 * nla_get_le64 - return payload of __le64 attribute
1650 * @nla: __le64 netlink attribute
1652 static inline __le64 nla_get_le64(const struct nlattr *nla)
1654 return *(__le64 *) nla_data(nla);
1658 * nla_get_s32 - return payload of s32 attribute
1659 * @nla: s32 netlink attribute
1661 static inline s32 nla_get_s32(const struct nlattr *nla)
1663 return *(s32 *) nla_data(nla);
1667 * nla_get_s16 - return payload of s16 attribute
1668 * @nla: s16 netlink attribute
1670 static inline s16 nla_get_s16(const struct nlattr *nla)
1672 return *(s16 *) nla_data(nla);
1676 * nla_get_s8 - return payload of s8 attribute
1677 * @nla: s8 netlink attribute
1679 static inline s8 nla_get_s8(const struct nlattr *nla)
1681 return *(s8 *) nla_data(nla);
1685 * nla_get_s64 - return payload of s64 attribute
1686 * @nla: s64 netlink attribute
1688 static inline s64 nla_get_s64(const struct nlattr *nla)
1692 nla_memcpy(&tmp, nla, sizeof(tmp));
1698 * nla_get_flag - return payload of flag attribute
1699 * @nla: flag netlink attribute
1701 static inline int nla_get_flag(const struct nlattr *nla)
1707 * nla_get_msecs - return payload of msecs attribute
1708 * @nla: msecs netlink attribute
1710 * Returns the number of milliseconds in jiffies.
1712 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1714 u64 msecs = nla_get_u64(nla);
1716 return msecs_to_jiffies((unsigned long) msecs);
1720 * nla_get_in_addr - return payload of IPv4 address attribute
1721 * @nla: IPv4 address netlink attribute
1723 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1725 return *(__be32 *) nla_data(nla);
1729 * nla_get_in6_addr - return payload of IPv6 address attribute
1730 * @nla: IPv6 address netlink attribute
1732 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1734 struct in6_addr tmp;
1736 nla_memcpy(&tmp, nla, sizeof(tmp));
1741 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1742 * @nla: nla_bitfield32 attribute
1744 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1746 struct nla_bitfield32 tmp;
1748 nla_memcpy(&tmp, nla, sizeof(tmp));
1753 * nla_memdup - duplicate attribute memory (kmemdup)
1754 * @src: netlink attribute to duplicate from
1757 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1759 return kmemdup(nla_data(src), nla_len(src), gfp);
1763 * nla_nest_start_noflag - Start a new level of nested attributes
1764 * @skb: socket buffer to add attributes to
1765 * @attrtype: attribute type of container
1767 * This function exists for backward compatibility to use in APIs which never
1768 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1769 * nla_nest_start() which sets the flag.
1771 * Returns the container attribute or NULL on error
1773 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1776 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1778 if (nla_put(skb, attrtype, 0, NULL) < 0)
1785 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1786 * @skb: socket buffer to add attributes to
1787 * @attrtype: attribute type of container
1789 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1790 * flag. This is the preferred function to use in new code.
1792 * Returns the container attribute or NULL on error
1794 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1796 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1800 * nla_nest_end - Finalize nesting of attributes
1801 * @skb: socket buffer the attributes are stored in
1802 * @start: container attribute
1804 * Corrects the container attribute header to include the all
1805 * appeneded attributes.
1807 * Returns the total data length of the skb.
1809 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1811 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1816 * nla_nest_cancel - Cancel nesting of attributes
1817 * @skb: socket buffer the message is stored in
1818 * @start: container attribute
1820 * Removes the container attribute and including all nested
1821 * attributes. Returns -EMSGSIZE
1823 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1825 nlmsg_trim(skb, start);
1829 * __nla_validate_nested - Validate a stream of nested attributes
1830 * @start: container attribute
1831 * @maxtype: maximum attribute type to be expected
1832 * @policy: validation policy
1833 * @validate: validation strictness
1834 * @extack: extended ACK report struct
1836 * Validates all attributes in the nested attribute stream against the
1837 * specified policy. Attributes with a type exceeding maxtype will be
1838 * ignored. See documenation of struct nla_policy for more details.
1840 * Returns 0 on success or a negative error code.
1842 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1843 const struct nla_policy *policy,
1844 unsigned int validate,
1845 struct netlink_ext_ack *extack)
1847 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1852 nla_validate_nested(const struct nlattr *start, int maxtype,
1853 const struct nla_policy *policy,
1854 struct netlink_ext_ack *extack)
1856 return __nla_validate_nested(start, maxtype, policy,
1857 NL_VALIDATE_STRICT, extack);
1861 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1862 const struct nla_policy *policy,
1863 struct netlink_ext_ack *extack)
1865 return __nla_validate_nested(start, maxtype, policy,
1866 NL_VALIDATE_LIBERAL, extack);
1870 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1871 * @skb: socket buffer the message is stored in
1873 * Return true if padding is needed to align the next attribute (nla_data()) to
1874 * a 64-bit aligned area.
1876 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1878 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1879 /* The nlattr header is 4 bytes in size, that's why we test
1880 * if the skb->data _is_ aligned. A NOP attribute, plus
1881 * nlattr header for next attribute, will make nla_data()
1884 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1891 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1892 * @skb: socket buffer the message is stored in
1893 * @padattr: attribute type for the padding
1895 * Conditionally emit a padding netlink attribute in order to make
1896 * the next attribute we emit have a 64-bit aligned nla_data() area.
1897 * This will only be done in architectures which do not have
1898 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1900 * Returns zero on success or a negative error code.
1902 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1904 if (nla_need_padding_for_64bit(skb) &&
1905 !nla_reserve(skb, padattr, 0))
1912 * nla_total_size_64bit - total length of attribute including padding
1913 * @payload: length of payload
1915 static inline int nla_total_size_64bit(int payload)
1917 return NLA_ALIGN(nla_attr_size(payload))
1918 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1919 + NLA_ALIGN(nla_attr_size(0))
1925 * nla_for_each_attr - iterate over a stream of attributes
1926 * @pos: loop counter, set to current attribute
1927 * @head: head of attribute stream
1928 * @len: length of attribute stream
1929 * @rem: initialized to len, holds bytes currently remaining in stream
1931 #define nla_for_each_attr(pos, head, len, rem) \
1932 for (pos = head, rem = len; \
1934 pos = nla_next(pos, &(rem)))
1937 * nla_for_each_nested - iterate over nested attributes
1938 * @pos: loop counter, set to current attribute
1939 * @nla: attribute containing the nested attributes
1940 * @rem: initialized to len, holds bytes currently remaining in stream
1942 #define nla_for_each_nested(pos, nla, rem) \
1943 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1946 * nla_is_last - Test if attribute is last in stream
1947 * @nla: attribute to test
1948 * @rem: bytes remaining in stream
1950 static inline bool nla_is_last(const struct nlattr *nla, int rem)
1952 return nla->nla_len == rem;
1955 void nla_get_range_unsigned(const struct nla_policy *pt,
1956 struct netlink_range_validation *range);
1957 void nla_get_range_signed(const struct nla_policy *pt,
1958 struct netlink_range_validation_signed *range);
1960 struct netlink_policy_dump_state;
1962 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
1963 const struct nla_policy *policy,
1964 unsigned int maxtype);
1965 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
1966 const struct nla_policy *policy,
1967 unsigned int maxtype);
1968 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
1969 int netlink_policy_dump_write(struct sk_buff *skb,
1970 struct netlink_policy_dump_state *state);
1971 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
1972 int netlink_policy_dump_write_attr(struct sk_buff *skb,
1973 const struct nla_policy *pt,
1975 void netlink_policy_dump_free(struct netlink_policy_dump_state *state);