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 using the NLA_POLICY_FULL_RANGE()
280 * or NLA_POLICY_FULL_RANGE_SIGNED() macros instead.
281 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
282 * NLA_POLICY_RANGE() macros.
286 * NLA_U64 If the validation_type field instead is set to
287 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
288 * to a struct netlink_range_validation that indicates
289 * the min/max values.
290 * Use NLA_POLICY_FULL_RANGE().
294 * NLA_S64 If the validation_type field instead is set to
295 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
296 * pointer to a struct netlink_range_validation_signed
297 * that indicates the min/max values.
298 * Use NLA_POLICY_FULL_RANGE_SIGNED().
300 * NLA_BINARY If the validation type is like the ones for integers
301 * above, then the min/max length (not value like for
302 * integers) of the attribute is enforced.
304 * All other Unused - but note that it's a union
306 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
307 * NLA_BINARY Validation function called for the attribute.
308 * All other Unused - but note that it's a union
312 * static const u32 myvalidflags = 0xff231023;
314 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
315 * [ATTR_FOO] = { .type = NLA_U16 },
316 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
317 * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)),
318 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
327 * @strict_start_type: first attribute to validate strictly
329 * This entry is special, and used for the attribute at index 0
330 * only, and specifies special data about the policy, namely it
331 * specifies the "boundary type" where strict length validation
332 * starts for any attribute types >= this value, also, strict
333 * nesting validation starts here.
335 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
336 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to
337 * get the previous pure { .len = xyz } behaviour. The advantage
338 * of this is that types not specified in the policy will be
341 * For completely new families it should be set to 1 so that the
342 * validation is enforced for all attributes. For existing ones
343 * it should be set at least when new attributes are added to
344 * the enum used by the policy, and be set to the new value that
345 * was added to enforce strict validation from thereon.
347 u16 strict_start_type;
349 /* private: use NLA_POLICY_*() to set */
350 const u32 bitfield32_valid;
352 const char *reject_message;
353 const struct nla_policy *nested_policy;
354 struct netlink_range_validation *range;
355 struct netlink_range_validation_signed *range_signed;
359 int (*validate)(const struct nlattr *attr,
360 struct netlink_ext_ack *extack);
364 #define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN)
365 #define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
367 #define _NLA_POLICY_NESTED(maxattr, policy) \
368 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
369 #define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
370 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
371 #define NLA_POLICY_NESTED(policy) \
372 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
373 #define NLA_POLICY_NESTED_ARRAY(policy) \
374 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
375 #define NLA_POLICY_BITFIELD32(valid) \
376 { .type = NLA_BITFIELD32, .bitfield32_valid = valid }
378 #define __NLA_IS_UINT_TYPE(tp) \
379 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || tp == NLA_U64)
380 #define __NLA_IS_SINT_TYPE(tp) \
381 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64)
382 #define __NLA_IS_BEINT_TYPE(tp) \
383 (tp == NLA_BE16 || tp == NLA_BE32)
385 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
386 #define NLA_ENSURE_UINT_TYPE(tp) \
387 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
388 #define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \
389 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
391 tp == NLA_BINARY) + tp)
392 #define NLA_ENSURE_SINT_TYPE(tp) \
393 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
394 #define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \
395 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
396 __NLA_IS_SINT_TYPE(tp) || \
397 __NLA_IS_BEINT_TYPE(tp) || \
399 tp == NLA_BINARY) + tp)
400 #define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
401 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \
402 tp != NLA_REJECT && \
403 tp != NLA_NESTED && \
404 tp != NLA_NESTED_ARRAY) + tp)
405 #define NLA_ENSURE_BEINT_TYPE(tp) \
406 (__NLA_ENSURE(__NLA_IS_BEINT_TYPE(tp)) + tp)
408 #define NLA_POLICY_RANGE(tp, _min, _max) { \
409 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
410 .validation_type = NLA_VALIDATE_RANGE, \
415 #define NLA_POLICY_FULL_RANGE(tp, _range) { \
416 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \
417 .validation_type = NLA_VALIDATE_RANGE_PTR, \
421 #define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \
422 .type = NLA_ENSURE_SINT_TYPE(tp), \
423 .validation_type = NLA_VALIDATE_RANGE_PTR, \
424 .range_signed = _range, \
427 #define NLA_POLICY_MIN(tp, _min) { \
428 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
429 .validation_type = NLA_VALIDATE_MIN, \
433 #define NLA_POLICY_MAX(tp, _max) { \
434 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
435 .validation_type = NLA_VALIDATE_MAX, \
439 #define NLA_POLICY_MASK(tp, _mask) { \
440 .type = NLA_ENSURE_UINT_TYPE(tp), \
441 .validation_type = NLA_VALIDATE_MASK, \
445 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \
446 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \
447 .validation_type = NLA_VALIDATE_FUNCTION, \
449 .len = __VA_ARGS__ + 0, \
452 #define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
453 #define NLA_POLICY_EXACT_LEN_WARN(_len) { \
454 .type = NLA_BINARY, \
455 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \
459 #define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len)
462 * struct nl_info - netlink source information
463 * @nlh: Netlink message header of original request
464 * @nl_net: Network namespace
465 * @portid: Netlink PORTID of requesting application
466 * @skip_notify: Skip netlink notifications to user space
467 * @skip_notify_kernel: Skip selected in-kernel notifications
470 struct nlmsghdr *nlh;
474 skip_notify_kernel:1;
478 * enum netlink_validation - netlink message/attribute validation levels
479 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
480 * extra data at the end of the message, attributes being longer than
481 * they should be, or unknown attributes being present.
482 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
483 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
484 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
485 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
486 * This can safely be set by the kernel when the given policy has no
487 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
488 * are enforced going forward.
489 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
490 * U8, U16, U32 must have exact size, etc.)
491 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
492 * and unset for other policies.
494 enum netlink_validation {
495 NL_VALIDATE_LIBERAL = 0,
496 NL_VALIDATE_TRAILING = BIT(0),
497 NL_VALIDATE_MAXTYPE = BIT(1),
498 NL_VALIDATE_UNSPEC = BIT(2),
499 NL_VALIDATE_STRICT_ATTRS = BIT(3),
500 NL_VALIDATE_NESTED = BIT(4),
503 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
505 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
506 NL_VALIDATE_MAXTYPE |\
507 NL_VALIDATE_UNSPEC |\
508 NL_VALIDATE_STRICT_ATTRS |\
511 int netlink_rcv_skb(struct sk_buff *skb,
512 int (*cb)(struct sk_buff *, struct nlmsghdr *,
513 struct netlink_ext_ack *));
514 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
515 unsigned int group, int report, gfp_t flags);
517 int __nla_validate(const struct nlattr *head, int len, int maxtype,
518 const struct nla_policy *policy, unsigned int validate,
519 struct netlink_ext_ack *extack);
520 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
521 int len, const struct nla_policy *policy, unsigned int validate,
522 struct netlink_ext_ack *extack);
523 int nla_policy_len(const struct nla_policy *, int);
524 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
525 ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
526 char *nla_strdup(const struct nlattr *nla, gfp_t flags);
527 int nla_memcpy(void *dest, const struct nlattr *src, int count);
528 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
529 int nla_strcmp(const struct nlattr *nla, const char *str);
530 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
531 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
532 int attrlen, int padattr);
533 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
534 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
535 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
536 int attrlen, int padattr);
537 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
538 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
540 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
541 const void *data, int padattr);
542 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
543 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
544 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
545 const void *data, int padattr);
546 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
547 int nla_append(struct sk_buff *skb, int attrlen, const void *data);
549 /**************************************************************************
551 **************************************************************************/
554 * nlmsg_msg_size - length of netlink message not including padding
555 * @payload: length of message payload
557 static inline int nlmsg_msg_size(int payload)
559 return NLMSG_HDRLEN + payload;
563 * nlmsg_total_size - length of netlink message including padding
564 * @payload: length of message payload
566 static inline int nlmsg_total_size(int payload)
568 return NLMSG_ALIGN(nlmsg_msg_size(payload));
572 * nlmsg_padlen - length of padding at the message's tail
573 * @payload: length of message payload
575 static inline int nlmsg_padlen(int payload)
577 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
581 * nlmsg_data - head of message payload
582 * @nlh: netlink message header
584 static inline void *nlmsg_data(const struct nlmsghdr *nlh)
586 return (unsigned char *) nlh + NLMSG_HDRLEN;
590 * nlmsg_len - length of message payload
591 * @nlh: netlink message header
593 static inline int nlmsg_len(const struct nlmsghdr *nlh)
595 return nlh->nlmsg_len - NLMSG_HDRLEN;
599 * nlmsg_attrdata - head of attributes data
600 * @nlh: netlink message header
601 * @hdrlen: length of family specific header
603 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
606 unsigned char *data = nlmsg_data(nlh);
607 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
611 * nlmsg_attrlen - length of attributes data
612 * @nlh: netlink message header
613 * @hdrlen: length of family specific header
615 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
617 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
621 * nlmsg_ok - check if the netlink message fits into the remaining bytes
622 * @nlh: netlink message header
623 * @remaining: number of bytes remaining in message stream
625 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
627 return (remaining >= (int) sizeof(struct nlmsghdr) &&
628 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
629 nlh->nlmsg_len <= remaining);
633 * nlmsg_next - next netlink message in message stream
634 * @nlh: netlink message header
635 * @remaining: number of bytes remaining in message stream
637 * Returns the next netlink message in the message stream and
638 * decrements remaining by the size of the current message.
640 static inline struct nlmsghdr *
641 nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
643 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
645 *remaining -= totlen;
647 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
651 * nla_parse - Parse a stream of attributes into a tb buffer
652 * @tb: destination array with maxtype+1 elements
653 * @maxtype: maximum attribute type to be expected
654 * @head: head of attribute stream
655 * @len: length of attribute stream
656 * @policy: validation policy
657 * @extack: extended ACK pointer
659 * Parses a stream of attributes and stores a pointer to each attribute in
660 * the tb array accessible via the attribute type. Attributes with a type
661 * exceeding maxtype will be rejected, policy must be specified, attributes
662 * will be validated in the strictest way possible.
664 * Returns 0 on success or a negative error code.
666 static inline int nla_parse(struct nlattr **tb, int maxtype,
667 const struct nlattr *head, int len,
668 const struct nla_policy *policy,
669 struct netlink_ext_ack *extack)
671 return __nla_parse(tb, maxtype, head, len, policy,
672 NL_VALIDATE_STRICT, extack);
676 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
677 * @tb: destination array with maxtype+1 elements
678 * @maxtype: maximum attribute type to be expected
679 * @head: head of attribute stream
680 * @len: length of attribute stream
681 * @policy: validation policy
682 * @extack: extended ACK pointer
684 * Parses a stream of attributes and stores a pointer to each attribute in
685 * the tb array accessible via the attribute type. Attributes with a type
686 * exceeding maxtype will be ignored and attributes from the policy are not
687 * always strictly validated (only for new attributes).
689 * Returns 0 on success or a negative error code.
691 static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
692 const struct nlattr *head, int len,
693 const struct nla_policy *policy,
694 struct netlink_ext_ack *extack)
696 return __nla_parse(tb, maxtype, head, len, policy,
697 NL_VALIDATE_LIBERAL, extack);
701 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
702 * @tb: destination array with maxtype+1 elements
703 * @maxtype: maximum attribute type to be expected
704 * @head: head of attribute stream
705 * @len: length of attribute stream
706 * @policy: validation policy
707 * @extack: extended ACK pointer
709 * Parses a stream of attributes and stores a pointer to each attribute in
710 * the tb array accessible via the attribute type. Attributes with a type
711 * exceeding maxtype will be rejected as well as trailing data, but the
712 * policy is not completely strictly validated (only for new attributes).
714 * Returns 0 on success or a negative error code.
716 static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
717 const struct nlattr *head,
719 const struct nla_policy *policy,
720 struct netlink_ext_ack *extack)
722 return __nla_parse(tb, maxtype, head, len, policy,
723 NL_VALIDATE_DEPRECATED_STRICT, extack);
727 * __nlmsg_parse - parse attributes of a netlink message
728 * @nlh: netlink message header
729 * @hdrlen: length of family specific header
730 * @tb: destination array with maxtype+1 elements
731 * @maxtype: maximum attribute type to be expected
732 * @policy: validation policy
733 * @validate: validation strictness
734 * @extack: extended ACK report struct
738 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
739 struct nlattr *tb[], int maxtype,
740 const struct nla_policy *policy,
741 unsigned int validate,
742 struct netlink_ext_ack *extack)
744 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
745 NL_SET_ERR_MSG(extack, "Invalid header length");
749 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
750 nlmsg_attrlen(nlh, hdrlen), policy, validate,
755 * nlmsg_parse - parse attributes of a netlink message
756 * @nlh: netlink message header
757 * @hdrlen: length of family specific header
758 * @tb: destination array with maxtype+1 elements
759 * @maxtype: maximum attribute type to be expected
760 * @policy: validation policy
761 * @extack: extended ACK report struct
765 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
766 struct nlattr *tb[], int maxtype,
767 const struct nla_policy *policy,
768 struct netlink_ext_ack *extack)
770 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
771 NL_VALIDATE_STRICT, extack);
775 * nlmsg_parse_deprecated - parse attributes of a netlink message
776 * @nlh: netlink message header
777 * @hdrlen: length of family specific header
778 * @tb: destination array with maxtype+1 elements
779 * @maxtype: maximum attribute type to be expected
780 * @policy: validation policy
781 * @extack: extended ACK report struct
783 * See nla_parse_deprecated()
785 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
786 struct nlattr *tb[], int maxtype,
787 const struct nla_policy *policy,
788 struct netlink_ext_ack *extack)
790 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
791 NL_VALIDATE_LIBERAL, extack);
795 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
796 * @nlh: netlink message header
797 * @hdrlen: length of family specific header
798 * @tb: destination array with maxtype+1 elements
799 * @maxtype: maximum attribute type to be expected
800 * @policy: validation policy
801 * @extack: extended ACK report struct
803 * See nla_parse_deprecated_strict()
806 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
807 struct nlattr *tb[], int maxtype,
808 const struct nla_policy *policy,
809 struct netlink_ext_ack *extack)
811 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
812 NL_VALIDATE_DEPRECATED_STRICT, extack);
816 * nlmsg_find_attr - find a specific attribute in a netlink message
817 * @nlh: netlink message header
818 * @hdrlen: length of familiy specific header
819 * @attrtype: type of attribute to look for
821 * Returns the first attribute which matches the specified type.
823 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
824 int hdrlen, int attrtype)
826 return nla_find(nlmsg_attrdata(nlh, hdrlen),
827 nlmsg_attrlen(nlh, hdrlen), attrtype);
831 * nla_validate_deprecated - Validate a stream of attributes
832 * @head: head of attribute stream
833 * @len: length of attribute stream
834 * @maxtype: maximum attribute type to be expected
835 * @policy: validation policy
836 * @extack: extended ACK report struct
838 * Validates all attributes in the specified attribute stream against the
839 * specified policy. Validation is done in liberal mode.
840 * See documenation of struct nla_policy for more details.
842 * Returns 0 on success or a negative error code.
844 static inline int nla_validate_deprecated(const struct nlattr *head, int len,
846 const struct nla_policy *policy,
847 struct netlink_ext_ack *extack)
849 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
854 * nla_validate - Validate a stream of attributes
855 * @head: head of attribute stream
856 * @len: length of attribute stream
857 * @maxtype: maximum attribute type to be expected
858 * @policy: validation policy
859 * @extack: extended ACK report struct
861 * Validates all attributes in the specified attribute stream against the
862 * specified policy. Validation is done in strict mode.
863 * See documenation of struct nla_policy for more details.
865 * Returns 0 on success or a negative error code.
867 static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
868 const struct nla_policy *policy,
869 struct netlink_ext_ack *extack)
871 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
876 * nlmsg_validate_deprecated - validate a netlink message including attributes
877 * @nlh: netlinket message header
878 * @hdrlen: length of familiy specific header
879 * @maxtype: maximum attribute type to be expected
880 * @policy: validation policy
881 * @extack: extended ACK report struct
883 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
884 int hdrlen, int maxtype,
885 const struct nla_policy *policy,
886 struct netlink_ext_ack *extack)
888 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
891 return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
892 nlmsg_attrlen(nlh, hdrlen), maxtype,
893 policy, NL_VALIDATE_LIBERAL, extack);
899 * nlmsg_report - need to report back to application?
900 * @nlh: netlink message header
902 * Returns 1 if a report back to the application is requested.
904 static inline int nlmsg_report(const struct nlmsghdr *nlh)
906 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
910 * nlmsg_seq - return the seq number of netlink message
911 * @nlh: netlink message header
913 * Returns 0 if netlink message is NULL
915 static inline u32 nlmsg_seq(const struct nlmsghdr *nlh)
917 return nlh ? nlh->nlmsg_seq : 0;
921 * nlmsg_for_each_attr - iterate over a stream of attributes
922 * @pos: loop counter, set to current attribute
923 * @nlh: netlink message header
924 * @hdrlen: length of familiy specific header
925 * @rem: initialized to len, holds bytes currently remaining in stream
927 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
928 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
929 nlmsg_attrlen(nlh, hdrlen), rem)
932 * nlmsg_put - Add a new netlink message to an skb
933 * @skb: socket buffer to store message in
934 * @portid: netlink PORTID of requesting application
935 * @seq: sequence number of message
936 * @type: message type
937 * @payload: length of message payload
938 * @flags: message flags
940 * Returns NULL if the tailroom of the skb is insufficient to store
941 * the message header and payload.
943 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
944 int type, int payload, int flags)
946 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
949 return __nlmsg_put(skb, portid, seq, type, payload, flags);
953 * nlmsg_append - Add more data to a nlmsg in a skb
954 * @skb: socket buffer to store message in
955 * @size: length of message payload
957 * Append data to an existing nlmsg, used when constructing a message
958 * with multiple fixed-format headers (which is rare).
959 * Returns NULL if the tailroom of the skb is insufficient to store
962 static inline void *nlmsg_append(struct sk_buff *skb, u32 size)
964 if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size)))
967 if (NLMSG_ALIGN(size) - size)
968 memset(skb_tail_pointer(skb) + size, 0,
969 NLMSG_ALIGN(size) - size);
970 return __skb_put(skb, NLMSG_ALIGN(size));
974 * nlmsg_put_answer - Add a new callback based netlink message to an skb
975 * @skb: socket buffer to store message in
976 * @cb: netlink callback
977 * @type: message type
978 * @payload: length of message payload
979 * @flags: message flags
981 * Returns NULL if the tailroom of the skb is insufficient to store
982 * the message header and payload.
984 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
985 struct netlink_callback *cb,
986 int type, int payload,
989 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
990 type, payload, flags);
994 * nlmsg_new - Allocate a new netlink message
995 * @payload: size of the message payload
996 * @flags: the type of memory to allocate.
998 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
999 * and a good default is needed.
1001 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
1003 return alloc_skb(nlmsg_total_size(payload), flags);
1007 * nlmsg_end - Finalize a netlink message
1008 * @skb: socket buffer the message is stored in
1009 * @nlh: netlink message header
1011 * Corrects the netlink message header to include the appeneded
1012 * attributes. Only necessary if attributes have been added to
1015 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
1017 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
1021 * nlmsg_get_pos - return current position in netlink message
1022 * @skb: socket buffer the message is stored in
1024 * Returns a pointer to the current tail of the message.
1026 static inline void *nlmsg_get_pos(struct sk_buff *skb)
1028 return skb_tail_pointer(skb);
1032 * nlmsg_trim - Trim message to a mark
1033 * @skb: socket buffer the message is stored in
1034 * @mark: mark to trim to
1036 * Trims the message to the provided mark.
1038 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1041 WARN_ON((unsigned char *) mark < skb->data);
1042 skb_trim(skb, (unsigned char *) mark - skb->data);
1047 * nlmsg_cancel - Cancel construction of a netlink message
1048 * @skb: socket buffer the message is stored in
1049 * @nlh: netlink message header
1051 * Removes the complete netlink message including all
1052 * attributes from the socket buffer again.
1054 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1056 nlmsg_trim(skb, nlh);
1060 * nlmsg_free - free a netlink message
1061 * @skb: socket buffer of netlink message
1063 static inline void nlmsg_free(struct sk_buff *skb)
1069 * nlmsg_multicast - multicast a netlink message
1070 * @sk: netlink socket to spread messages to
1071 * @skb: netlink message as socket buffer
1072 * @portid: own netlink portid to avoid sending to yourself
1073 * @group: multicast group id
1074 * @flags: allocation flags
1076 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1077 u32 portid, unsigned int group, gfp_t flags)
1081 NETLINK_CB(skb).dst_group = group;
1083 err = netlink_broadcast(sk, skb, portid, group, flags);
1091 * nlmsg_unicast - unicast a netlink message
1092 * @sk: netlink socket to spread message to
1093 * @skb: netlink message as socket buffer
1094 * @portid: netlink portid of the destination socket
1096 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1100 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1108 * nlmsg_for_each_msg - iterate over a stream of messages
1109 * @pos: loop counter, set to current message
1110 * @head: head of message stream
1111 * @len: length of message stream
1112 * @rem: initialized to len, holds bytes currently remaining in stream
1114 #define nlmsg_for_each_msg(pos, head, len, rem) \
1115 for (pos = head, rem = len; \
1116 nlmsg_ok(pos, rem); \
1117 pos = nlmsg_next(pos, &(rem)))
1120 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1121 * @cb: netlink callback structure that stores the sequence number
1122 * @nlh: netlink message header to write the flag to
1124 * This function checks if the sequence (generation) number changed during dump
1125 * and if it did, advertises it in the netlink message header.
1127 * The correct way to use it is to set cb->seq to the generation counter when
1128 * all locks for dumping have been acquired, and then call this function for
1129 * each message that is generated.
1131 * Note that due to initialisation concerns, 0 is an invalid sequence number
1132 * and must not be used by code that uses this functionality.
1135 nl_dump_check_consistent(struct netlink_callback *cb,
1136 struct nlmsghdr *nlh)
1138 if (cb->prev_seq && cb->seq != cb->prev_seq)
1139 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1140 cb->prev_seq = cb->seq;
1143 /**************************************************************************
1144 * Netlink Attributes
1145 **************************************************************************/
1148 * nla_attr_size - length of attribute not including padding
1149 * @payload: length of payload
1151 static inline int nla_attr_size(int payload)
1153 return NLA_HDRLEN + payload;
1157 * nla_total_size - total length of attribute including padding
1158 * @payload: length of payload
1160 static inline int nla_total_size(int payload)
1162 return NLA_ALIGN(nla_attr_size(payload));
1166 * nla_padlen - length of padding at the tail of attribute
1167 * @payload: length of payload
1169 static inline int nla_padlen(int payload)
1171 return nla_total_size(payload) - nla_attr_size(payload);
1175 * nla_type - attribute type
1176 * @nla: netlink attribute
1178 static inline int nla_type(const struct nlattr *nla)
1180 return nla->nla_type & NLA_TYPE_MASK;
1184 * nla_data - head of payload
1185 * @nla: netlink attribute
1187 static inline void *nla_data(const struct nlattr *nla)
1189 return (char *) nla + NLA_HDRLEN;
1193 * nla_len - length of payload
1194 * @nla: netlink attribute
1196 static inline int nla_len(const struct nlattr *nla)
1198 return nla->nla_len - NLA_HDRLEN;
1202 * nla_ok - check if the netlink attribute fits into the remaining bytes
1203 * @nla: netlink attribute
1204 * @remaining: number of bytes remaining in attribute stream
1206 static inline int nla_ok(const struct nlattr *nla, int remaining)
1208 return remaining >= (int) sizeof(*nla) &&
1209 nla->nla_len >= sizeof(*nla) &&
1210 nla->nla_len <= remaining;
1214 * nla_next - next netlink attribute in attribute stream
1215 * @nla: netlink attribute
1216 * @remaining: number of bytes remaining in attribute stream
1218 * Returns the next netlink attribute in the attribute stream and
1219 * decrements remaining by the size of the current attribute.
1221 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1223 unsigned int totlen = NLA_ALIGN(nla->nla_len);
1225 *remaining -= totlen;
1226 return (struct nlattr *) ((char *) nla + totlen);
1230 * nla_find_nested - find attribute in a set of nested attributes
1231 * @nla: attribute containing the nested attributes
1232 * @attrtype: type of attribute to look for
1234 * Returns the first attribute which matches the specified type.
1236 static inline struct nlattr *
1237 nla_find_nested(const struct nlattr *nla, int attrtype)
1239 return nla_find(nla_data(nla), nla_len(nla), attrtype);
1243 * nla_parse_nested - parse nested attributes
1244 * @tb: destination array with maxtype+1 elements
1245 * @maxtype: maximum attribute type to be expected
1246 * @nla: attribute containing the nested attributes
1247 * @policy: validation policy
1248 * @extack: extended ACK report struct
1252 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1253 const struct nlattr *nla,
1254 const struct nla_policy *policy,
1255 struct netlink_ext_ack *extack)
1257 if (!(nla->nla_type & NLA_F_NESTED)) {
1258 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1262 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1263 NL_VALIDATE_STRICT, extack);
1267 * nla_parse_nested_deprecated - parse nested attributes
1268 * @tb: destination array with maxtype+1 elements
1269 * @maxtype: maximum attribute type to be expected
1270 * @nla: attribute containing the nested attributes
1271 * @policy: validation policy
1272 * @extack: extended ACK report struct
1274 * See nla_parse_deprecated()
1276 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1277 const struct nlattr *nla,
1278 const struct nla_policy *policy,
1279 struct netlink_ext_ack *extack)
1281 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1282 NL_VALIDATE_LIBERAL, extack);
1286 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1287 * @skb: socket buffer to add attribute to
1288 * @attrtype: attribute type
1289 * @value: numeric value
1291 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1293 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
1296 return nla_put(skb, attrtype, sizeof(u8), &tmp);
1300 * nla_put_u16 - Add a u16 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_u16(struct sk_buff *skb, int attrtype, u16 value)
1309 return nla_put(skb, attrtype, sizeof(u16), &tmp);
1313 * nla_put_be16 - Add a __be16 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_be16(struct sk_buff *skb, int attrtype, __be16 value)
1322 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1326 * nla_put_net16 - Add 16-bit network byte order 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_net16(struct sk_buff *skb, int attrtype, __be16 value)
1335 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1339 * nla_put_le16 - Add a __le16 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_le16(struct sk_buff *skb, int attrtype, __le16 value)
1348 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1352 * nla_put_u32 - Add a u32 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_u32(struct sk_buff *skb, int attrtype, u32 value)
1361 return nla_put(skb, attrtype, sizeof(u32), &tmp);
1365 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1366 * @skb: socket buffer to add attribute to
1367 * @attrtype: attribute type
1368 * @value: numeric value
1370 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1374 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1378 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1379 * @skb: socket buffer to add attribute to
1380 * @attrtype: attribute type
1381 * @value: numeric value
1383 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1387 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1391 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1392 * @skb: socket buffer to add attribute to
1393 * @attrtype: attribute type
1394 * @value: numeric value
1396 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1400 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1404 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1405 * @skb: socket buffer to add attribute to
1406 * @attrtype: attribute type
1407 * @value: numeric value
1408 * @padattr: attribute type for the padding
1410 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1411 u64 value, int padattr)
1415 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1419 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1420 * @skb: socket buffer to add attribute to
1421 * @attrtype: attribute type
1422 * @value: numeric value
1423 * @padattr: attribute type for the padding
1425 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1430 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1434 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1435 * @skb: socket buffer to add attribute to
1436 * @attrtype: attribute type
1437 * @value: numeric value
1438 * @padattr: attribute type for the padding
1440 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1445 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1450 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1451 * @skb: socket buffer to add attribute to
1452 * @attrtype: attribute type
1453 * @value: numeric value
1454 * @padattr: attribute type for the padding
1456 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1461 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1465 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1466 * @skb: socket buffer to add attribute to
1467 * @attrtype: attribute type
1468 * @value: numeric value
1470 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1474 return nla_put(skb, attrtype, sizeof(s8), &tmp);
1478 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1479 * @skb: socket buffer to add attribute to
1480 * @attrtype: attribute type
1481 * @value: numeric value
1483 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1487 return nla_put(skb, attrtype, sizeof(s16), &tmp);
1491 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1492 * @skb: socket buffer to add attribute to
1493 * @attrtype: attribute type
1494 * @value: numeric value
1496 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1500 return nla_put(skb, attrtype, sizeof(s32), &tmp);
1504 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1505 * @skb: socket buffer to add attribute to
1506 * @attrtype: attribute type
1507 * @value: numeric value
1508 * @padattr: attribute type for the padding
1510 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1515 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1519 * nla_put_string - Add a string netlink attribute to a socket buffer
1520 * @skb: socket buffer to add attribute to
1521 * @attrtype: attribute type
1522 * @str: NUL terminated string
1524 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1527 return nla_put(skb, attrtype, strlen(str) + 1, str);
1531 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1532 * @skb: socket buffer to add attribute to
1533 * @attrtype: attribute type
1535 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1537 return nla_put(skb, attrtype, 0, NULL);
1541 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1542 * @skb: socket buffer to add attribute to
1543 * @attrtype: attribute type
1544 * @njiffies: number of jiffies to convert to msecs
1545 * @padattr: attribute type for the padding
1547 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1548 unsigned long njiffies, int padattr)
1550 u64 tmp = jiffies_to_msecs(njiffies);
1552 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1556 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1558 * @skb: socket buffer to add attribute to
1559 * @attrtype: attribute type
1560 * @addr: IPv4 address
1562 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1567 return nla_put_be32(skb, attrtype, tmp);
1571 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1573 * @skb: socket buffer to add attribute to
1574 * @attrtype: attribute type
1575 * @addr: IPv6 address
1577 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1578 const struct in6_addr *addr)
1580 return nla_put(skb, attrtype, sizeof(*addr), addr);
1584 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1585 * @skb: socket buffer to add attribute to
1586 * @attrtype: attribute type
1587 * @value: value carrying bits
1588 * @selector: selector of valid bits
1590 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1591 __u32 value, __u32 selector)
1593 struct nla_bitfield32 tmp = { value, selector, };
1595 return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1599 * nla_get_u32 - return payload of u32 attribute
1600 * @nla: u32 netlink attribute
1602 static inline u32 nla_get_u32(const struct nlattr *nla)
1604 return *(u32 *) nla_data(nla);
1608 * nla_get_be32 - return payload of __be32 attribute
1609 * @nla: __be32 netlink attribute
1611 static inline __be32 nla_get_be32(const struct nlattr *nla)
1613 return *(__be32 *) nla_data(nla);
1617 * nla_get_le32 - return payload of __le32 attribute
1618 * @nla: __le32 netlink attribute
1620 static inline __le32 nla_get_le32(const struct nlattr *nla)
1622 return *(__le32 *) nla_data(nla);
1626 * nla_get_u16 - return payload of u16 attribute
1627 * @nla: u16 netlink attribute
1629 static inline u16 nla_get_u16(const struct nlattr *nla)
1631 return *(u16 *) nla_data(nla);
1635 * nla_get_be16 - return payload of __be16 attribute
1636 * @nla: __be16 netlink attribute
1638 static inline __be16 nla_get_be16(const struct nlattr *nla)
1640 return *(__be16 *) nla_data(nla);
1644 * nla_get_le16 - return payload of __le16 attribute
1645 * @nla: __le16 netlink attribute
1647 static inline __le16 nla_get_le16(const struct nlattr *nla)
1649 return *(__le16 *) nla_data(nla);
1653 * nla_get_u8 - return payload of u8 attribute
1654 * @nla: u8 netlink attribute
1656 static inline u8 nla_get_u8(const struct nlattr *nla)
1658 return *(u8 *) nla_data(nla);
1662 * nla_get_u64 - return payload of u64 attribute
1663 * @nla: u64 netlink attribute
1665 static inline u64 nla_get_u64(const struct nlattr *nla)
1669 nla_memcpy(&tmp, nla, sizeof(tmp));
1675 * nla_get_be64 - return payload of __be64 attribute
1676 * @nla: __be64 netlink attribute
1678 static inline __be64 nla_get_be64(const struct nlattr *nla)
1682 nla_memcpy(&tmp, nla, sizeof(tmp));
1688 * nla_get_le64 - return payload of __le64 attribute
1689 * @nla: __le64 netlink attribute
1691 static inline __le64 nla_get_le64(const struct nlattr *nla)
1693 return *(__le64 *) nla_data(nla);
1697 * nla_get_s32 - return payload of s32 attribute
1698 * @nla: s32 netlink attribute
1700 static inline s32 nla_get_s32(const struct nlattr *nla)
1702 return *(s32 *) nla_data(nla);
1706 * nla_get_s16 - return payload of s16 attribute
1707 * @nla: s16 netlink attribute
1709 static inline s16 nla_get_s16(const struct nlattr *nla)
1711 return *(s16 *) nla_data(nla);
1715 * nla_get_s8 - return payload of s8 attribute
1716 * @nla: s8 netlink attribute
1718 static inline s8 nla_get_s8(const struct nlattr *nla)
1720 return *(s8 *) nla_data(nla);
1724 * nla_get_s64 - return payload of s64 attribute
1725 * @nla: s64 netlink attribute
1727 static inline s64 nla_get_s64(const struct nlattr *nla)
1731 nla_memcpy(&tmp, nla, sizeof(tmp));
1737 * nla_get_flag - return payload of flag attribute
1738 * @nla: flag netlink attribute
1740 static inline int nla_get_flag(const struct nlattr *nla)
1746 * nla_get_msecs - return payload of msecs attribute
1747 * @nla: msecs netlink attribute
1749 * Returns the number of milliseconds in jiffies.
1751 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1753 u64 msecs = nla_get_u64(nla);
1755 return msecs_to_jiffies((unsigned long) msecs);
1759 * nla_get_in_addr - return payload of IPv4 address attribute
1760 * @nla: IPv4 address netlink attribute
1762 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1764 return *(__be32 *) nla_data(nla);
1768 * nla_get_in6_addr - return payload of IPv6 address attribute
1769 * @nla: IPv6 address netlink attribute
1771 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1773 struct in6_addr tmp;
1775 nla_memcpy(&tmp, nla, sizeof(tmp));
1780 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1781 * @nla: nla_bitfield32 attribute
1783 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1785 struct nla_bitfield32 tmp;
1787 nla_memcpy(&tmp, nla, sizeof(tmp));
1792 * nla_memdup - duplicate attribute memory (kmemdup)
1793 * @src: netlink attribute to duplicate from
1796 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1798 return kmemdup(nla_data(src), nla_len(src), gfp);
1802 * nla_nest_start_noflag - Start a new level of nested attributes
1803 * @skb: socket buffer to add attributes to
1804 * @attrtype: attribute type of container
1806 * This function exists for backward compatibility to use in APIs which never
1807 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1808 * nla_nest_start() which sets the flag.
1810 * Returns the container attribute or NULL on error
1812 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1815 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1817 if (nla_put(skb, attrtype, 0, NULL) < 0)
1824 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1825 * @skb: socket buffer to add attributes to
1826 * @attrtype: attribute type of container
1828 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1829 * flag. This is the preferred function to use in new code.
1831 * Returns the container attribute or NULL on error
1833 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1835 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1839 * nla_nest_end - Finalize nesting of attributes
1840 * @skb: socket buffer the attributes are stored in
1841 * @start: container attribute
1843 * Corrects the container attribute header to include the all
1844 * appeneded attributes.
1846 * Returns the total data length of the skb.
1848 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1850 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1855 * nla_nest_cancel - Cancel nesting of attributes
1856 * @skb: socket buffer the message is stored in
1857 * @start: container attribute
1859 * Removes the container attribute and including all nested
1860 * attributes. Returns -EMSGSIZE
1862 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1864 nlmsg_trim(skb, start);
1868 * __nla_validate_nested - Validate a stream of nested attributes
1869 * @start: container attribute
1870 * @maxtype: maximum attribute type to be expected
1871 * @policy: validation policy
1872 * @validate: validation strictness
1873 * @extack: extended ACK report struct
1875 * Validates all attributes in the nested attribute stream against the
1876 * specified policy. Attributes with a type exceeding maxtype will be
1877 * ignored. See documenation of struct nla_policy for more details.
1879 * Returns 0 on success or a negative error code.
1881 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1882 const struct nla_policy *policy,
1883 unsigned int validate,
1884 struct netlink_ext_ack *extack)
1886 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1891 nla_validate_nested(const struct nlattr *start, int maxtype,
1892 const struct nla_policy *policy,
1893 struct netlink_ext_ack *extack)
1895 return __nla_validate_nested(start, maxtype, policy,
1896 NL_VALIDATE_STRICT, extack);
1900 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1901 const struct nla_policy *policy,
1902 struct netlink_ext_ack *extack)
1904 return __nla_validate_nested(start, maxtype, policy,
1905 NL_VALIDATE_LIBERAL, extack);
1909 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1910 * @skb: socket buffer the message is stored in
1912 * Return true if padding is needed to align the next attribute (nla_data()) to
1913 * a 64-bit aligned area.
1915 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1917 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1918 /* The nlattr header is 4 bytes in size, that's why we test
1919 * if the skb->data _is_ aligned. A NOP attribute, plus
1920 * nlattr header for next attribute, will make nla_data()
1923 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1930 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1931 * @skb: socket buffer the message is stored in
1932 * @padattr: attribute type for the padding
1934 * Conditionally emit a padding netlink attribute in order to make
1935 * the next attribute we emit have a 64-bit aligned nla_data() area.
1936 * This will only be done in architectures which do not have
1937 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1939 * Returns zero on success or a negative error code.
1941 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1943 if (nla_need_padding_for_64bit(skb) &&
1944 !nla_reserve(skb, padattr, 0))
1951 * nla_total_size_64bit - total length of attribute including padding
1952 * @payload: length of payload
1954 static inline int nla_total_size_64bit(int payload)
1956 return NLA_ALIGN(nla_attr_size(payload))
1957 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1958 + NLA_ALIGN(nla_attr_size(0))
1964 * nla_for_each_attr - iterate over a stream of attributes
1965 * @pos: loop counter, set to current attribute
1966 * @head: head of attribute stream
1967 * @len: length of attribute stream
1968 * @rem: initialized to len, holds bytes currently remaining in stream
1970 #define nla_for_each_attr(pos, head, len, rem) \
1971 for (pos = head, rem = len; \
1973 pos = nla_next(pos, &(rem)))
1976 * nla_for_each_nested - iterate over nested attributes
1977 * @pos: loop counter, set to current attribute
1978 * @nla: attribute containing the nested attributes
1979 * @rem: initialized to len, holds bytes currently remaining in stream
1981 #define nla_for_each_nested(pos, nla, rem) \
1982 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1985 * nla_is_last - Test if attribute is last in stream
1986 * @nla: attribute to test
1987 * @rem: bytes remaining in stream
1989 static inline bool nla_is_last(const struct nlattr *nla, int rem)
1991 return nla->nla_len == rem;
1994 void nla_get_range_unsigned(const struct nla_policy *pt,
1995 struct netlink_range_validation *range);
1996 void nla_get_range_signed(const struct nla_policy *pt,
1997 struct netlink_range_validation_signed *range);
1999 struct netlink_policy_dump_state;
2001 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
2002 const struct nla_policy *policy,
2003 unsigned int maxtype);
2004 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
2005 const struct nla_policy *policy,
2006 unsigned int maxtype);
2007 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
2008 int netlink_policy_dump_write(struct sk_buff *skb,
2009 struct netlink_policy_dump_state *state);
2010 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
2011 int netlink_policy_dump_write_attr(struct sk_buff *skb,
2012 const struct nla_policy *pt,
2014 void netlink_policy_dump_free(struct netlink_policy_dump_state *state);