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 || \
380 tp == NLA_U64 || tp == NLA_BE16 || tp == NLA_BE32)
381 #define __NLA_IS_SINT_TYPE(tp) \
382 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64)
384 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
385 #define NLA_ENSURE_UINT_TYPE(tp) \
386 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
387 #define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \
388 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
390 tp == NLA_BINARY) + tp)
391 #define NLA_ENSURE_SINT_TYPE(tp) \
392 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
393 #define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \
394 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
395 __NLA_IS_SINT_TYPE(tp) || \
397 tp == NLA_BINARY) + tp)
398 #define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
399 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \
400 tp != NLA_REJECT && \
401 tp != NLA_NESTED && \
402 tp != NLA_NESTED_ARRAY) + tp)
404 #define NLA_POLICY_RANGE(tp, _min, _max) { \
405 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
406 .validation_type = NLA_VALIDATE_RANGE, \
411 #define NLA_POLICY_FULL_RANGE(tp, _range) { \
412 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \
413 .validation_type = NLA_VALIDATE_RANGE_PTR, \
417 #define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \
418 .type = NLA_ENSURE_SINT_TYPE(tp), \
419 .validation_type = NLA_VALIDATE_RANGE_PTR, \
420 .range_signed = _range, \
423 #define NLA_POLICY_MIN(tp, _min) { \
424 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
425 .validation_type = NLA_VALIDATE_MIN, \
429 #define NLA_POLICY_MAX(tp, _max) { \
430 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
431 .validation_type = NLA_VALIDATE_MAX, \
435 #define NLA_POLICY_MASK(tp, _mask) { \
436 .type = NLA_ENSURE_UINT_TYPE(tp), \
437 .validation_type = NLA_VALIDATE_MASK, \
441 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \
442 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \
443 .validation_type = NLA_VALIDATE_FUNCTION, \
445 .len = __VA_ARGS__ + 0, \
448 #define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
449 #define NLA_POLICY_EXACT_LEN_WARN(_len) { \
450 .type = NLA_BINARY, \
451 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \
455 #define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len)
458 * struct nl_info - netlink source information
459 * @nlh: Netlink message header of original request
460 * @nl_net: Network namespace
461 * @portid: Netlink PORTID of requesting application
462 * @skip_notify: Skip netlink notifications to user space
463 * @skip_notify_kernel: Skip selected in-kernel notifications
466 struct nlmsghdr *nlh;
470 skip_notify_kernel:1;
474 * enum netlink_validation - netlink message/attribute validation levels
475 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
476 * extra data at the end of the message, attributes being longer than
477 * they should be, or unknown attributes being present.
478 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
479 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
480 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
481 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
482 * This can safely be set by the kernel when the given policy has no
483 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
484 * are enforced going forward.
485 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
486 * U8, U16, U32 must have exact size, etc.)
487 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
488 * and unset for other policies.
490 enum netlink_validation {
491 NL_VALIDATE_LIBERAL = 0,
492 NL_VALIDATE_TRAILING = BIT(0),
493 NL_VALIDATE_MAXTYPE = BIT(1),
494 NL_VALIDATE_UNSPEC = BIT(2),
495 NL_VALIDATE_STRICT_ATTRS = BIT(3),
496 NL_VALIDATE_NESTED = BIT(4),
499 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
501 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
502 NL_VALIDATE_MAXTYPE |\
503 NL_VALIDATE_UNSPEC |\
504 NL_VALIDATE_STRICT_ATTRS |\
507 int netlink_rcv_skb(struct sk_buff *skb,
508 int (*cb)(struct sk_buff *, struct nlmsghdr *,
509 struct netlink_ext_ack *));
510 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
511 unsigned int group, int report, gfp_t flags);
513 int __nla_validate(const struct nlattr *head, int len, int maxtype,
514 const struct nla_policy *policy, unsigned int validate,
515 struct netlink_ext_ack *extack);
516 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
517 int len, const struct nla_policy *policy, unsigned int validate,
518 struct netlink_ext_ack *extack);
519 int nla_policy_len(const struct nla_policy *, int);
520 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
521 ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
522 char *nla_strdup(const struct nlattr *nla, gfp_t flags);
523 int nla_memcpy(void *dest, const struct nlattr *src, int count);
524 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
525 int nla_strcmp(const struct nlattr *nla, const char *str);
526 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
527 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
528 int attrlen, int padattr);
529 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
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 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
536 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
537 const void *data, int padattr);
538 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
539 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
540 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
541 const void *data, int padattr);
542 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
543 int nla_append(struct sk_buff *skb, int attrlen, const void *data);
545 /**************************************************************************
547 **************************************************************************/
550 * nlmsg_msg_size - length of netlink message not including padding
551 * @payload: length of message payload
553 static inline int nlmsg_msg_size(int payload)
555 return NLMSG_HDRLEN + payload;
559 * nlmsg_total_size - length of netlink message including padding
560 * @payload: length of message payload
562 static inline int nlmsg_total_size(int payload)
564 return NLMSG_ALIGN(nlmsg_msg_size(payload));
568 * nlmsg_padlen - length of padding at the message's tail
569 * @payload: length of message payload
571 static inline int nlmsg_padlen(int payload)
573 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
577 * nlmsg_data - head of message payload
578 * @nlh: netlink message header
580 static inline void *nlmsg_data(const struct nlmsghdr *nlh)
582 return (unsigned char *) nlh + NLMSG_HDRLEN;
586 * nlmsg_len - length of message payload
587 * @nlh: netlink message header
589 static inline int nlmsg_len(const struct nlmsghdr *nlh)
591 return nlh->nlmsg_len - NLMSG_HDRLEN;
595 * nlmsg_attrdata - head of attributes data
596 * @nlh: netlink message header
597 * @hdrlen: length of family specific header
599 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
602 unsigned char *data = nlmsg_data(nlh);
603 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
607 * nlmsg_attrlen - length of attributes data
608 * @nlh: netlink message header
609 * @hdrlen: length of family specific header
611 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
613 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
617 * nlmsg_ok - check if the netlink message fits into the remaining bytes
618 * @nlh: netlink message header
619 * @remaining: number of bytes remaining in message stream
621 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
623 return (remaining >= (int) sizeof(struct nlmsghdr) &&
624 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
625 nlh->nlmsg_len <= remaining);
629 * nlmsg_next - next netlink message in message stream
630 * @nlh: netlink message header
631 * @remaining: number of bytes remaining in message stream
633 * Returns the next netlink message in the message stream and
634 * decrements remaining by the size of the current message.
636 static inline struct nlmsghdr *
637 nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
639 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
641 *remaining -= totlen;
643 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
647 * nla_parse - Parse a stream of attributes into a tb buffer
648 * @tb: destination array with maxtype+1 elements
649 * @maxtype: maximum attribute type to be expected
650 * @head: head of attribute stream
651 * @len: length of attribute stream
652 * @policy: validation policy
653 * @extack: extended ACK pointer
655 * Parses a stream of attributes and stores a pointer to each attribute in
656 * the tb array accessible via the attribute type. Attributes with a type
657 * exceeding maxtype will be rejected, policy must be specified, attributes
658 * will be validated in the strictest way possible.
660 * Returns 0 on success or a negative error code.
662 static inline int nla_parse(struct nlattr **tb, int maxtype,
663 const struct nlattr *head, int len,
664 const struct nla_policy *policy,
665 struct netlink_ext_ack *extack)
667 return __nla_parse(tb, maxtype, head, len, policy,
668 NL_VALIDATE_STRICT, extack);
672 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
673 * @tb: destination array with maxtype+1 elements
674 * @maxtype: maximum attribute type to be expected
675 * @head: head of attribute stream
676 * @len: length of attribute stream
677 * @policy: validation policy
678 * @extack: extended ACK pointer
680 * Parses a stream of attributes and stores a pointer to each attribute in
681 * the tb array accessible via the attribute type. Attributes with a type
682 * exceeding maxtype will be ignored and attributes from the policy are not
683 * always strictly validated (only for new attributes).
685 * Returns 0 on success or a negative error code.
687 static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
688 const struct nlattr *head, int len,
689 const struct nla_policy *policy,
690 struct netlink_ext_ack *extack)
692 return __nla_parse(tb, maxtype, head, len, policy,
693 NL_VALIDATE_LIBERAL, extack);
697 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
698 * @tb: destination array with maxtype+1 elements
699 * @maxtype: maximum attribute type to be expected
700 * @head: head of attribute stream
701 * @len: length of attribute stream
702 * @policy: validation policy
703 * @extack: extended ACK pointer
705 * Parses a stream of attributes and stores a pointer to each attribute in
706 * the tb array accessible via the attribute type. Attributes with a type
707 * exceeding maxtype will be rejected as well as trailing data, but the
708 * policy is not completely strictly validated (only for new attributes).
710 * Returns 0 on success or a negative error code.
712 static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
713 const struct nlattr *head,
715 const struct nla_policy *policy,
716 struct netlink_ext_ack *extack)
718 return __nla_parse(tb, maxtype, head, len, policy,
719 NL_VALIDATE_DEPRECATED_STRICT, extack);
723 * __nlmsg_parse - parse attributes of a netlink message
724 * @nlh: netlink message header
725 * @hdrlen: length of family specific header
726 * @tb: destination array with maxtype+1 elements
727 * @maxtype: maximum attribute type to be expected
728 * @policy: validation policy
729 * @validate: validation strictness
730 * @extack: extended ACK report struct
734 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
735 struct nlattr *tb[], int maxtype,
736 const struct nla_policy *policy,
737 unsigned int validate,
738 struct netlink_ext_ack *extack)
740 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
741 NL_SET_ERR_MSG(extack, "Invalid header length");
745 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
746 nlmsg_attrlen(nlh, hdrlen), policy, validate,
751 * nlmsg_parse - parse attributes of a netlink message
752 * @nlh: netlink message header
753 * @hdrlen: length of family specific header
754 * @tb: destination array with maxtype+1 elements
755 * @maxtype: maximum attribute type to be expected
756 * @policy: validation policy
757 * @extack: extended ACK report struct
761 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
762 struct nlattr *tb[], int maxtype,
763 const struct nla_policy *policy,
764 struct netlink_ext_ack *extack)
766 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
767 NL_VALIDATE_STRICT, extack);
771 * nlmsg_parse_deprecated - parse attributes of a netlink message
772 * @nlh: netlink message header
773 * @hdrlen: length of family specific header
774 * @tb: destination array with maxtype+1 elements
775 * @maxtype: maximum attribute type to be expected
776 * @policy: validation policy
777 * @extack: extended ACK report struct
779 * See nla_parse_deprecated()
781 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
782 struct nlattr *tb[], int maxtype,
783 const struct nla_policy *policy,
784 struct netlink_ext_ack *extack)
786 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
787 NL_VALIDATE_LIBERAL, extack);
791 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
792 * @nlh: netlink message header
793 * @hdrlen: length of family specific header
794 * @tb: destination array with maxtype+1 elements
795 * @maxtype: maximum attribute type to be expected
796 * @policy: validation policy
797 * @extack: extended ACK report struct
799 * See nla_parse_deprecated_strict()
802 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
803 struct nlattr *tb[], int maxtype,
804 const struct nla_policy *policy,
805 struct netlink_ext_ack *extack)
807 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
808 NL_VALIDATE_DEPRECATED_STRICT, extack);
812 * nlmsg_find_attr - find a specific attribute in a netlink message
813 * @nlh: netlink message header
814 * @hdrlen: length of familiy specific header
815 * @attrtype: type of attribute to look for
817 * Returns the first attribute which matches the specified type.
819 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
820 int hdrlen, int attrtype)
822 return nla_find(nlmsg_attrdata(nlh, hdrlen),
823 nlmsg_attrlen(nlh, hdrlen), attrtype);
827 * nla_validate_deprecated - Validate a stream of attributes
828 * @head: head of attribute stream
829 * @len: length of attribute stream
830 * @maxtype: maximum attribute type to be expected
831 * @policy: validation policy
832 * @extack: extended ACK report struct
834 * Validates all attributes in the specified attribute stream against the
835 * specified policy. Validation is done in liberal mode.
836 * See documenation of struct nla_policy for more details.
838 * Returns 0 on success or a negative error code.
840 static inline int nla_validate_deprecated(const struct nlattr *head, int len,
842 const struct nla_policy *policy,
843 struct netlink_ext_ack *extack)
845 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
850 * nla_validate - Validate a stream of attributes
851 * @head: head of attribute stream
852 * @len: length of attribute stream
853 * @maxtype: maximum attribute type to be expected
854 * @policy: validation policy
855 * @extack: extended ACK report struct
857 * Validates all attributes in the specified attribute stream against the
858 * specified policy. Validation is done in strict mode.
859 * See documenation of struct nla_policy for more details.
861 * Returns 0 on success or a negative error code.
863 static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
864 const struct nla_policy *policy,
865 struct netlink_ext_ack *extack)
867 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
872 * nlmsg_validate_deprecated - validate a netlink message including attributes
873 * @nlh: netlinket message header
874 * @hdrlen: length of familiy specific header
875 * @maxtype: maximum attribute type to be expected
876 * @policy: validation policy
877 * @extack: extended ACK report struct
879 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
880 int hdrlen, int maxtype,
881 const struct nla_policy *policy,
882 struct netlink_ext_ack *extack)
884 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
887 return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
888 nlmsg_attrlen(nlh, hdrlen), maxtype,
889 policy, NL_VALIDATE_LIBERAL, extack);
895 * nlmsg_report - need to report back to application?
896 * @nlh: netlink message header
898 * Returns 1 if a report back to the application is requested.
900 static inline int nlmsg_report(const struct nlmsghdr *nlh)
902 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
906 * nlmsg_seq - return the seq number of netlink message
907 * @nlh: netlink message header
909 * Returns 0 if netlink message is NULL
911 static inline u32 nlmsg_seq(const struct nlmsghdr *nlh)
913 return nlh ? nlh->nlmsg_seq : 0;
917 * nlmsg_for_each_attr - iterate over a stream of attributes
918 * @pos: loop counter, set to current attribute
919 * @nlh: netlink message header
920 * @hdrlen: length of familiy specific header
921 * @rem: initialized to len, holds bytes currently remaining in stream
923 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
924 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
925 nlmsg_attrlen(nlh, hdrlen), rem)
928 * nlmsg_put - Add a new netlink message to an skb
929 * @skb: socket buffer to store message in
930 * @portid: netlink PORTID of requesting application
931 * @seq: sequence number of message
932 * @type: message type
933 * @payload: length of message payload
934 * @flags: message flags
936 * Returns NULL if the tailroom of the skb is insufficient to store
937 * the message header and payload.
939 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
940 int type, int payload, int flags)
942 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
945 return __nlmsg_put(skb, portid, seq, type, payload, flags);
949 * nlmsg_append - Add more data to a nlmsg in a skb
950 * @skb: socket buffer to store message in
951 * @size: length of message payload
953 * Append data to an existing nlmsg, used when constructing a message
954 * with multiple fixed-format headers (which is rare).
955 * Returns NULL if the tailroom of the skb is insufficient to store
958 static inline void *nlmsg_append(struct sk_buff *skb, u32 size)
960 if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size)))
963 if (NLMSG_ALIGN(size) - size)
964 memset(skb_tail_pointer(skb) + size, 0,
965 NLMSG_ALIGN(size) - size);
966 return __skb_put(skb, NLMSG_ALIGN(size));
970 * nlmsg_put_answer - Add a new callback based netlink message to an skb
971 * @skb: socket buffer to store message in
972 * @cb: netlink callback
973 * @type: message type
974 * @payload: length of message payload
975 * @flags: message flags
977 * Returns NULL if the tailroom of the skb is insufficient to store
978 * the message header and payload.
980 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
981 struct netlink_callback *cb,
982 int type, int payload,
985 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
986 type, payload, flags);
990 * nlmsg_new - Allocate a new netlink message
991 * @payload: size of the message payload
992 * @flags: the type of memory to allocate.
994 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
995 * and a good default is needed.
997 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
999 return alloc_skb(nlmsg_total_size(payload), flags);
1003 * nlmsg_end - Finalize a netlink message
1004 * @skb: socket buffer the message is stored in
1005 * @nlh: netlink message header
1007 * Corrects the netlink message header to include the appeneded
1008 * attributes. Only necessary if attributes have been added to
1011 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
1013 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
1017 * nlmsg_get_pos - return current position in netlink message
1018 * @skb: socket buffer the message is stored in
1020 * Returns a pointer to the current tail of the message.
1022 static inline void *nlmsg_get_pos(struct sk_buff *skb)
1024 return skb_tail_pointer(skb);
1028 * nlmsg_trim - Trim message to a mark
1029 * @skb: socket buffer the message is stored in
1030 * @mark: mark to trim to
1032 * Trims the message to the provided mark.
1034 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1037 WARN_ON((unsigned char *) mark < skb->data);
1038 skb_trim(skb, (unsigned char *) mark - skb->data);
1043 * nlmsg_cancel - Cancel construction of a netlink message
1044 * @skb: socket buffer the message is stored in
1045 * @nlh: netlink message header
1047 * Removes the complete netlink message including all
1048 * attributes from the socket buffer again.
1050 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1052 nlmsg_trim(skb, nlh);
1056 * nlmsg_free - free a netlink message
1057 * @skb: socket buffer of netlink message
1059 static inline void nlmsg_free(struct sk_buff *skb)
1065 * nlmsg_multicast - multicast a netlink message
1066 * @sk: netlink socket to spread messages to
1067 * @skb: netlink message as socket buffer
1068 * @portid: own netlink portid to avoid sending to yourself
1069 * @group: multicast group id
1070 * @flags: allocation flags
1072 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1073 u32 portid, unsigned int group, gfp_t flags)
1077 NETLINK_CB(skb).dst_group = group;
1079 err = netlink_broadcast(sk, skb, portid, group, flags);
1087 * nlmsg_unicast - unicast a netlink message
1088 * @sk: netlink socket to spread message to
1089 * @skb: netlink message as socket buffer
1090 * @portid: netlink portid of the destination socket
1092 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1096 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1104 * nlmsg_for_each_msg - iterate over a stream of messages
1105 * @pos: loop counter, set to current message
1106 * @head: head of message stream
1107 * @len: length of message stream
1108 * @rem: initialized to len, holds bytes currently remaining in stream
1110 #define nlmsg_for_each_msg(pos, head, len, rem) \
1111 for (pos = head, rem = len; \
1112 nlmsg_ok(pos, rem); \
1113 pos = nlmsg_next(pos, &(rem)))
1116 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1117 * @cb: netlink callback structure that stores the sequence number
1118 * @nlh: netlink message header to write the flag to
1120 * This function checks if the sequence (generation) number changed during dump
1121 * and if it did, advertises it in the netlink message header.
1123 * The correct way to use it is to set cb->seq to the generation counter when
1124 * all locks for dumping have been acquired, and then call this function for
1125 * each message that is generated.
1127 * Note that due to initialisation concerns, 0 is an invalid sequence number
1128 * and must not be used by code that uses this functionality.
1131 nl_dump_check_consistent(struct netlink_callback *cb,
1132 struct nlmsghdr *nlh)
1134 if (cb->prev_seq && cb->seq != cb->prev_seq)
1135 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1136 cb->prev_seq = cb->seq;
1139 /**************************************************************************
1140 * Netlink Attributes
1141 **************************************************************************/
1144 * nla_attr_size - length of attribute not including padding
1145 * @payload: length of payload
1147 static inline int nla_attr_size(int payload)
1149 return NLA_HDRLEN + payload;
1153 * nla_total_size - total length of attribute including padding
1154 * @payload: length of payload
1156 static inline int nla_total_size(int payload)
1158 return NLA_ALIGN(nla_attr_size(payload));
1162 * nla_padlen - length of padding at the tail of attribute
1163 * @payload: length of payload
1165 static inline int nla_padlen(int payload)
1167 return nla_total_size(payload) - nla_attr_size(payload);
1171 * nla_type - attribute type
1172 * @nla: netlink attribute
1174 static inline int nla_type(const struct nlattr *nla)
1176 return nla->nla_type & NLA_TYPE_MASK;
1180 * nla_data - head of payload
1181 * @nla: netlink attribute
1183 static inline void *nla_data(const struct nlattr *nla)
1185 return (char *) nla + NLA_HDRLEN;
1189 * nla_len - length of payload
1190 * @nla: netlink attribute
1192 static inline int nla_len(const struct nlattr *nla)
1194 return nla->nla_len - NLA_HDRLEN;
1198 * nla_ok - check if the netlink attribute fits into the remaining bytes
1199 * @nla: netlink attribute
1200 * @remaining: number of bytes remaining in attribute stream
1202 static inline int nla_ok(const struct nlattr *nla, int remaining)
1204 return remaining >= (int) sizeof(*nla) &&
1205 nla->nla_len >= sizeof(*nla) &&
1206 nla->nla_len <= remaining;
1210 * nla_next - next netlink attribute in attribute stream
1211 * @nla: netlink attribute
1212 * @remaining: number of bytes remaining in attribute stream
1214 * Returns the next netlink attribute in the attribute stream and
1215 * decrements remaining by the size of the current attribute.
1217 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1219 unsigned int totlen = NLA_ALIGN(nla->nla_len);
1221 *remaining -= totlen;
1222 return (struct nlattr *) ((char *) nla + totlen);
1226 * nla_find_nested - find attribute in a set of nested attributes
1227 * @nla: attribute containing the nested attributes
1228 * @attrtype: type of attribute to look for
1230 * Returns the first attribute which matches the specified type.
1232 static inline struct nlattr *
1233 nla_find_nested(const struct nlattr *nla, int attrtype)
1235 return nla_find(nla_data(nla), nla_len(nla), attrtype);
1239 * nla_parse_nested - parse nested attributes
1240 * @tb: destination array with maxtype+1 elements
1241 * @maxtype: maximum attribute type to be expected
1242 * @nla: attribute containing the nested attributes
1243 * @policy: validation policy
1244 * @extack: extended ACK report struct
1248 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1249 const struct nlattr *nla,
1250 const struct nla_policy *policy,
1251 struct netlink_ext_ack *extack)
1253 if (!(nla->nla_type & NLA_F_NESTED)) {
1254 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1258 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1259 NL_VALIDATE_STRICT, extack);
1263 * nla_parse_nested_deprecated - parse nested attributes
1264 * @tb: destination array with maxtype+1 elements
1265 * @maxtype: maximum attribute type to be expected
1266 * @nla: attribute containing the nested attributes
1267 * @policy: validation policy
1268 * @extack: extended ACK report struct
1270 * See nla_parse_deprecated()
1272 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1273 const struct nlattr *nla,
1274 const struct nla_policy *policy,
1275 struct netlink_ext_ack *extack)
1277 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1278 NL_VALIDATE_LIBERAL, extack);
1282 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1283 * @skb: socket buffer to add attribute to
1284 * @attrtype: attribute type
1285 * @value: numeric value
1287 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1289 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
1292 return nla_put(skb, attrtype, sizeof(u8), &tmp);
1296 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1297 * @skb: socket buffer to add attribute to
1298 * @attrtype: attribute type
1299 * @value: numeric value
1301 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1305 return nla_put(skb, attrtype, sizeof(u16), &tmp);
1309 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1310 * @skb: socket buffer to add attribute to
1311 * @attrtype: attribute type
1312 * @value: numeric value
1314 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1318 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1322 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1323 * @skb: socket buffer to add attribute to
1324 * @attrtype: attribute type
1325 * @value: numeric value
1327 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1331 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1335 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1336 * @skb: socket buffer to add attribute to
1337 * @attrtype: attribute type
1338 * @value: numeric value
1340 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1344 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1348 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1349 * @skb: socket buffer to add attribute to
1350 * @attrtype: attribute type
1351 * @value: numeric value
1353 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1357 return nla_put(skb, attrtype, sizeof(u32), &tmp);
1361 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1362 * @skb: socket buffer to add attribute to
1363 * @attrtype: attribute type
1364 * @value: numeric value
1366 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1370 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1374 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1375 * @skb: socket buffer to add attribute to
1376 * @attrtype: attribute type
1377 * @value: numeric value
1379 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1383 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1387 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1388 * @skb: socket buffer to add attribute to
1389 * @attrtype: attribute type
1390 * @value: numeric value
1392 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1396 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1400 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1401 * @skb: socket buffer to add attribute to
1402 * @attrtype: attribute type
1403 * @value: numeric value
1404 * @padattr: attribute type for the padding
1406 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1407 u64 value, int padattr)
1411 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1415 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1416 * @skb: socket buffer to add attribute to
1417 * @attrtype: attribute type
1418 * @value: numeric value
1419 * @padattr: attribute type for the padding
1421 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1426 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1430 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1431 * @skb: socket buffer to add attribute to
1432 * @attrtype: attribute type
1433 * @value: numeric value
1434 * @padattr: attribute type for the padding
1436 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1441 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1446 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1447 * @skb: socket buffer to add attribute to
1448 * @attrtype: attribute type
1449 * @value: numeric value
1450 * @padattr: attribute type for the padding
1452 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1457 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1461 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1462 * @skb: socket buffer to add attribute to
1463 * @attrtype: attribute type
1464 * @value: numeric value
1466 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1470 return nla_put(skb, attrtype, sizeof(s8), &tmp);
1474 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1475 * @skb: socket buffer to add attribute to
1476 * @attrtype: attribute type
1477 * @value: numeric value
1479 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1483 return nla_put(skb, attrtype, sizeof(s16), &tmp);
1487 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1488 * @skb: socket buffer to add attribute to
1489 * @attrtype: attribute type
1490 * @value: numeric value
1492 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1496 return nla_put(skb, attrtype, sizeof(s32), &tmp);
1500 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1501 * @skb: socket buffer to add attribute to
1502 * @attrtype: attribute type
1503 * @value: numeric value
1504 * @padattr: attribute type for the padding
1506 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1511 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1515 * nla_put_string - Add a string netlink attribute to a socket buffer
1516 * @skb: socket buffer to add attribute to
1517 * @attrtype: attribute type
1518 * @str: NUL terminated string
1520 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1523 return nla_put(skb, attrtype, strlen(str) + 1, str);
1527 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1528 * @skb: socket buffer to add attribute to
1529 * @attrtype: attribute type
1531 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1533 return nla_put(skb, attrtype, 0, NULL);
1537 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1538 * @skb: socket buffer to add attribute to
1539 * @attrtype: attribute type
1540 * @njiffies: number of jiffies to convert to msecs
1541 * @padattr: attribute type for the padding
1543 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1544 unsigned long njiffies, int padattr)
1546 u64 tmp = jiffies_to_msecs(njiffies);
1548 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1552 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1554 * @skb: socket buffer to add attribute to
1555 * @attrtype: attribute type
1556 * @addr: IPv4 address
1558 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1563 return nla_put_be32(skb, attrtype, tmp);
1567 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1569 * @skb: socket buffer to add attribute to
1570 * @attrtype: attribute type
1571 * @addr: IPv6 address
1573 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1574 const struct in6_addr *addr)
1576 return nla_put(skb, attrtype, sizeof(*addr), addr);
1580 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1581 * @skb: socket buffer to add attribute to
1582 * @attrtype: attribute type
1583 * @value: value carrying bits
1584 * @selector: selector of valid bits
1586 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1587 __u32 value, __u32 selector)
1589 struct nla_bitfield32 tmp = { value, selector, };
1591 return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1595 * nla_get_u32 - return payload of u32 attribute
1596 * @nla: u32 netlink attribute
1598 static inline u32 nla_get_u32(const struct nlattr *nla)
1600 return *(u32 *) nla_data(nla);
1604 * nla_get_be32 - return payload of __be32 attribute
1605 * @nla: __be32 netlink attribute
1607 static inline __be32 nla_get_be32(const struct nlattr *nla)
1609 return *(__be32 *) nla_data(nla);
1613 * nla_get_le32 - return payload of __le32 attribute
1614 * @nla: __le32 netlink attribute
1616 static inline __le32 nla_get_le32(const struct nlattr *nla)
1618 return *(__le32 *) nla_data(nla);
1622 * nla_get_u16 - return payload of u16 attribute
1623 * @nla: u16 netlink attribute
1625 static inline u16 nla_get_u16(const struct nlattr *nla)
1627 return *(u16 *) nla_data(nla);
1631 * nla_get_be16 - return payload of __be16 attribute
1632 * @nla: __be16 netlink attribute
1634 static inline __be16 nla_get_be16(const struct nlattr *nla)
1636 return *(__be16 *) nla_data(nla);
1640 * nla_get_le16 - return payload of __le16 attribute
1641 * @nla: __le16 netlink attribute
1643 static inline __le16 nla_get_le16(const struct nlattr *nla)
1645 return *(__le16 *) nla_data(nla);
1649 * nla_get_u8 - return payload of u8 attribute
1650 * @nla: u8 netlink attribute
1652 static inline u8 nla_get_u8(const struct nlattr *nla)
1654 return *(u8 *) nla_data(nla);
1658 * nla_get_u64 - return payload of u64 attribute
1659 * @nla: u64 netlink attribute
1661 static inline u64 nla_get_u64(const struct nlattr *nla)
1665 nla_memcpy(&tmp, nla, sizeof(tmp));
1671 * nla_get_be64 - return payload of __be64 attribute
1672 * @nla: __be64 netlink attribute
1674 static inline __be64 nla_get_be64(const struct nlattr *nla)
1678 nla_memcpy(&tmp, nla, sizeof(tmp));
1684 * nla_get_le64 - return payload of __le64 attribute
1685 * @nla: __le64 netlink attribute
1687 static inline __le64 nla_get_le64(const struct nlattr *nla)
1689 return *(__le64 *) nla_data(nla);
1693 * nla_get_s32 - return payload of s32 attribute
1694 * @nla: s32 netlink attribute
1696 static inline s32 nla_get_s32(const struct nlattr *nla)
1698 return *(s32 *) nla_data(nla);
1702 * nla_get_s16 - return payload of s16 attribute
1703 * @nla: s16 netlink attribute
1705 static inline s16 nla_get_s16(const struct nlattr *nla)
1707 return *(s16 *) nla_data(nla);
1711 * nla_get_s8 - return payload of s8 attribute
1712 * @nla: s8 netlink attribute
1714 static inline s8 nla_get_s8(const struct nlattr *nla)
1716 return *(s8 *) nla_data(nla);
1720 * nla_get_s64 - return payload of s64 attribute
1721 * @nla: s64 netlink attribute
1723 static inline s64 nla_get_s64(const struct nlattr *nla)
1727 nla_memcpy(&tmp, nla, sizeof(tmp));
1733 * nla_get_flag - return payload of flag attribute
1734 * @nla: flag netlink attribute
1736 static inline int nla_get_flag(const struct nlattr *nla)
1742 * nla_get_msecs - return payload of msecs attribute
1743 * @nla: msecs netlink attribute
1745 * Returns the number of milliseconds in jiffies.
1747 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1749 u64 msecs = nla_get_u64(nla);
1751 return msecs_to_jiffies((unsigned long) msecs);
1755 * nla_get_in_addr - return payload of IPv4 address attribute
1756 * @nla: IPv4 address netlink attribute
1758 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1760 return *(__be32 *) nla_data(nla);
1764 * nla_get_in6_addr - return payload of IPv6 address attribute
1765 * @nla: IPv6 address netlink attribute
1767 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1769 struct in6_addr tmp;
1771 nla_memcpy(&tmp, nla, sizeof(tmp));
1776 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1777 * @nla: nla_bitfield32 attribute
1779 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1781 struct nla_bitfield32 tmp;
1783 nla_memcpy(&tmp, nla, sizeof(tmp));
1788 * nla_memdup - duplicate attribute memory (kmemdup)
1789 * @src: netlink attribute to duplicate from
1792 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1794 return kmemdup(nla_data(src), nla_len(src), gfp);
1798 * nla_nest_start_noflag - Start a new level of nested attributes
1799 * @skb: socket buffer to add attributes to
1800 * @attrtype: attribute type of container
1802 * This function exists for backward compatibility to use in APIs which never
1803 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1804 * nla_nest_start() which sets the flag.
1806 * Returns the container attribute or NULL on error
1808 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1811 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1813 if (nla_put(skb, attrtype, 0, NULL) < 0)
1820 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1821 * @skb: socket buffer to add attributes to
1822 * @attrtype: attribute type of container
1824 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1825 * flag. This is the preferred function to use in new code.
1827 * Returns the container attribute or NULL on error
1829 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1831 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1835 * nla_nest_end - Finalize nesting of attributes
1836 * @skb: socket buffer the attributes are stored in
1837 * @start: container attribute
1839 * Corrects the container attribute header to include the all
1840 * appeneded attributes.
1842 * Returns the total data length of the skb.
1844 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1846 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1851 * nla_nest_cancel - Cancel nesting of attributes
1852 * @skb: socket buffer the message is stored in
1853 * @start: container attribute
1855 * Removes the container attribute and including all nested
1856 * attributes. Returns -EMSGSIZE
1858 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1860 nlmsg_trim(skb, start);
1864 * __nla_validate_nested - Validate a stream of nested attributes
1865 * @start: container attribute
1866 * @maxtype: maximum attribute type to be expected
1867 * @policy: validation policy
1868 * @validate: validation strictness
1869 * @extack: extended ACK report struct
1871 * Validates all attributes in the nested attribute stream against the
1872 * specified policy. Attributes with a type exceeding maxtype will be
1873 * ignored. See documenation of struct nla_policy for more details.
1875 * Returns 0 on success or a negative error code.
1877 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1878 const struct nla_policy *policy,
1879 unsigned int validate,
1880 struct netlink_ext_ack *extack)
1882 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1887 nla_validate_nested(const struct nlattr *start, int maxtype,
1888 const struct nla_policy *policy,
1889 struct netlink_ext_ack *extack)
1891 return __nla_validate_nested(start, maxtype, policy,
1892 NL_VALIDATE_STRICT, extack);
1896 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1897 const struct nla_policy *policy,
1898 struct netlink_ext_ack *extack)
1900 return __nla_validate_nested(start, maxtype, policy,
1901 NL_VALIDATE_LIBERAL, extack);
1905 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1906 * @skb: socket buffer the message is stored in
1908 * Return true if padding is needed to align the next attribute (nla_data()) to
1909 * a 64-bit aligned area.
1911 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1913 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1914 /* The nlattr header is 4 bytes in size, that's why we test
1915 * if the skb->data _is_ aligned. A NOP attribute, plus
1916 * nlattr header for next attribute, will make nla_data()
1919 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1926 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1927 * @skb: socket buffer the message is stored in
1928 * @padattr: attribute type for the padding
1930 * Conditionally emit a padding netlink attribute in order to make
1931 * the next attribute we emit have a 64-bit aligned nla_data() area.
1932 * This will only be done in architectures which do not have
1933 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1935 * Returns zero on success or a negative error code.
1937 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1939 if (nla_need_padding_for_64bit(skb) &&
1940 !nla_reserve(skb, padattr, 0))
1947 * nla_total_size_64bit - total length of attribute including padding
1948 * @payload: length of payload
1950 static inline int nla_total_size_64bit(int payload)
1952 return NLA_ALIGN(nla_attr_size(payload))
1953 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1954 + NLA_ALIGN(nla_attr_size(0))
1960 * nla_for_each_attr - iterate over a stream of attributes
1961 * @pos: loop counter, set to current attribute
1962 * @head: head of attribute stream
1963 * @len: length of attribute stream
1964 * @rem: initialized to len, holds bytes currently remaining in stream
1966 #define nla_for_each_attr(pos, head, len, rem) \
1967 for (pos = head, rem = len; \
1969 pos = nla_next(pos, &(rem)))
1972 * nla_for_each_nested - iterate over nested attributes
1973 * @pos: loop counter, set to current attribute
1974 * @nla: attribute containing the nested attributes
1975 * @rem: initialized to len, holds bytes currently remaining in stream
1977 #define nla_for_each_nested(pos, nla, rem) \
1978 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1981 * nla_is_last - Test if attribute is last in stream
1982 * @nla: attribute to test
1983 * @rem: bytes remaining in stream
1985 static inline bool nla_is_last(const struct nlattr *nla, int rem)
1987 return nla->nla_len == rem;
1990 void nla_get_range_unsigned(const struct nla_policy *pt,
1991 struct netlink_range_validation *range);
1992 void nla_get_range_signed(const struct nla_policy *pt,
1993 struct netlink_range_validation_signed *range);
1995 struct netlink_policy_dump_state;
1997 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
1998 const struct nla_policy *policy,
1999 unsigned int maxtype);
2000 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
2001 const struct nla_policy *policy,
2002 unsigned int maxtype);
2003 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
2004 int netlink_policy_dump_write(struct sk_buff *skb,
2005 struct netlink_policy_dump_state *state);
2006 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
2007 int netlink_policy_dump_write_attr(struct sk_buff *skb,
2008 const struct nla_policy *pt,
2010 void netlink_policy_dump_free(struct netlink_policy_dump_state *state);