1 #ifndef __NET_NETLINK_H
2 #define __NET_NETLINK_H
4 #include <linux/types.h>
5 #include <linux/netlink.h>
6 #include <linux/jiffies.h>
9 /* ========================================================================
10 * Netlink Messages and Attributes Interface (As Seen On TV)
11 * ------------------------------------------------------------------------
13 * ------------------------------------------------------------------------
16 * <--- nlmsg_total_size(payload) --->
17 * <-- nlmsg_msg_size(payload) ->
18 * +----------+- - -+-------------+- - -+-------- - -
19 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr
20 * +----------+- - -+-------------+- - -+-------- - -
21 * nlmsg_data(nlh)---^ ^
22 * nlmsg_next(nlh)-----------------------+
25 * <---------------------- nlmsg_len(nlh) --------------------->
26 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
27 * +----------------------+- - -+--------------------------------+
28 * | Family Header | Pad | Attributes |
29 * +----------------------+- - -+--------------------------------+
30 * nlmsg_attrdata(nlh, hdrlen)---^
33 * struct nlmsghdr netlink message header
35 * Message Construction:
36 * nlmsg_new() create a new netlink message
37 * nlmsg_put() add a netlink message to an skb
38 * nlmsg_put_answer() callback based nlmsg_put()
39 * nlmsg_end() finalize netlink message
40 * nlmsg_get_pos() return current position in message
41 * nlmsg_trim() trim part of message
42 * nlmsg_cancel() cancel message construction
43 * nlmsg_free() free a netlink message
46 * nlmsg_multicast() multicast message to several groups
47 * nlmsg_unicast() unicast a message to a single socket
48 * nlmsg_notify() send notification message
50 * Message Length Calculations:
51 * nlmsg_msg_size(payload) length of message w/o padding
52 * nlmsg_total_size(payload) length of message w/ padding
53 * nlmsg_padlen(payload) length of padding at tail
55 * Message Payload Access:
56 * nlmsg_data(nlh) head of message payload
57 * nlmsg_len(nlh) length of message payload
58 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
59 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
62 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
63 * nlmsg_next(nlh, remaining) get next netlink message
64 * nlmsg_parse() parse attributes of a message
65 * nlmsg_find_attr() find an attribute in a message
66 * nlmsg_for_each_msg() loop over all messages
67 * nlmsg_validate() validate netlink message incl. attrs
68 * nlmsg_for_each_attr() loop over all attributes
71 * nlmsg_report() report back to application?
73 * ------------------------------------------------------------------------
74 * Attributes Interface
75 * ------------------------------------------------------------------------
78 * <------- nla_total_size(payload) ------->
79 * <---- nla_attr_size(payload) ----->
80 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
81 * | Header | Pad | Payload | Pad | Header
82 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
83 * <- nla_len(nla) -> ^
84 * nla_data(nla)----^ |
85 * nla_next(nla)-----------------------------'
88 * struct nlattr netlink attribute header
90 * Attribute Construction:
91 * nla_reserve(skb, type, len) reserve room for an attribute
92 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
93 * nla_put(skb, type, len, data) add attribute to skb
94 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
95 * nla_append(skb, len, data) append data to skb
97 * Attribute Construction for Basic Types:
98 * nla_put_u8(skb, type, value) add u8 attribute to skb
99 * nla_put_u16(skb, type, value) add u16 attribute to skb
100 * nla_put_u32(skb, type, value) add u32 attribute to skb
101 * nla_put_u64_64bit(skb, type,
102 * value, padattr) add u64 attribute to skb
103 * nla_put_s8(skb, type, value) add s8 attribute to skb
104 * nla_put_s16(skb, type, value) add s16 attribute to skb
105 * nla_put_s32(skb, type, value) add s32 attribute to skb
106 * nla_put_s64(skb, type, value,
107 * padattr) add s64 attribute to skb
108 * nla_put_string(skb, type, str) add string attribute to skb
109 * nla_put_flag(skb, type) add flag attribute to skb
110 * nla_put_msecs(skb, type, jiffies,
111 * padattr) add msecs attribute to skb
112 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb
113 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb
115 * Nested Attributes Construction:
116 * nla_nest_start(skb, type) start a nested attribute
117 * nla_nest_end(skb, nla) finalize a nested attribute
118 * nla_nest_cancel(skb, nla) cancel nested attribute construction
120 * Attribute Length Calculations:
121 * nla_attr_size(payload) length of attribute w/o padding
122 * nla_total_size(payload) length of attribute w/ padding
123 * nla_padlen(payload) length of padding
125 * Attribute Payload Access:
126 * nla_data(nla) head of attribute payload
127 * nla_len(nla) length of attribute payload
129 * Attribute Payload Access for Basic Types:
130 * nla_get_u8(nla) get payload for a u8 attribute
131 * nla_get_u16(nla) get payload for a u16 attribute
132 * nla_get_u32(nla) get payload for a u32 attribute
133 * nla_get_u64(nla) get payload for a u64 attribute
134 * nla_get_s8(nla) get payload for a s8 attribute
135 * nla_get_s16(nla) get payload for a s16 attribute
136 * nla_get_s32(nla) get payload for a s32 attribute
137 * nla_get_s64(nla) get payload for a s64 attribute
138 * nla_get_flag(nla) return 1 if flag is true
139 * nla_get_msecs(nla) get payload for a msecs attribute
142 * nla_memcpy(dest, nla, count) copy attribute into memory
143 * nla_memcmp(nla, data, size) compare attribute with memory area
144 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
145 * nla_strcmp(nla, str) compare attribute with string
148 * nla_ok(nla, remaining) does nla fit into remaining bytes?
149 * nla_next(nla, remaining) get next netlink attribute
150 * nla_validate() validate a stream of attributes
151 * nla_validate_nested() validate a stream of nested attributes
152 * nla_find() find attribute in stream of attributes
153 * nla_find_nested() find attribute in nested attributes
154 * nla_parse() parse and validate stream of attrs
155 * nla_parse_nested() parse nested attribuets
156 * nla_for_each_attr() loop over all attributes
157 * nla_for_each_nested() loop over the nested attributes
158 *=========================================================================
162 * Standard attribute types to specify validation policy
185 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
188 * struct nla_policy - attribute validation policy
189 * @type: Type of attribute or NLA_UNSPEC
190 * @len: Type specific length of payload
192 * Policies are defined as arrays of this struct, the array must be
193 * accessible by attribute type up to the highest identifier to be expected.
195 * Meaning of `len' field:
196 * NLA_STRING Maximum length of string
197 * NLA_NUL_STRING Maximum length of string (excluding NUL)
199 * NLA_BINARY Maximum length of attribute payload
200 * NLA_NESTED Don't use `len' field -- length verification is
201 * done by checking len of nested header (or empty)
202 * NLA_NESTED_COMPAT Minimum length of structure payload
207 * NLA_MSECS Leaving the length field zero will verify the
208 * given type fits, using it verifies minimum length
209 * just like "All other"
210 * NLA_BITFIELD32 A 32-bit bitmap/bitselector attribute
211 * All other Minimum length of attribute payload
214 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
215 * [ATTR_FOO] = { .type = NLA_U16 },
216 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
217 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
218 * [ATTR_GOO] = { .type = NLA_BITFIELD32, .validation_data = &myvalidflags },
224 void *validation_data;
228 * struct nl_info - netlink source information
229 * @nlh: Netlink message header of original request
230 * @portid: Netlink PORTID of requesting application
233 struct nlmsghdr *nlh;
239 int netlink_rcv_skb(struct sk_buff *skb,
240 int (*cb)(struct sk_buff *, struct nlmsghdr *,
241 struct netlink_ext_ack *));
242 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
243 unsigned int group, int report, gfp_t flags);
245 int nla_validate(const struct nlattr *head, int len, int maxtype,
246 const struct nla_policy *policy,
247 struct netlink_ext_ack *extack);
248 int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
249 int len, const struct nla_policy *policy,
250 struct netlink_ext_ack *extack);
251 int nla_policy_len(const struct nla_policy *, int);
252 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
253 size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
254 char *nla_strdup(const struct nlattr *nla, gfp_t flags);
255 int nla_memcpy(void *dest, const struct nlattr *src, int count);
256 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
257 int nla_strcmp(const struct nlattr *nla, const char *str);
258 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
259 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
260 int attrlen, int padattr);
261 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
262 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
263 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
264 int attrlen, int padattr);
265 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
266 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
268 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
269 const void *data, int padattr);
270 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
271 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
272 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
273 const void *data, int padattr);
274 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
275 int nla_append(struct sk_buff *skb, int attrlen, const void *data);
277 /**************************************************************************
279 **************************************************************************/
282 * nlmsg_msg_size - length of netlink message not including padding
283 * @payload: length of message payload
285 static inline int nlmsg_msg_size(int payload)
287 return NLMSG_HDRLEN + payload;
291 * nlmsg_total_size - length of netlink message including padding
292 * @payload: length of message payload
294 static inline int nlmsg_total_size(int payload)
296 return NLMSG_ALIGN(nlmsg_msg_size(payload));
300 * nlmsg_padlen - length of padding at the message's tail
301 * @payload: length of message payload
303 static inline int nlmsg_padlen(int payload)
305 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
309 * nlmsg_data - head of message payload
310 * @nlh: netlink message header
312 static inline void *nlmsg_data(const struct nlmsghdr *nlh)
314 return (unsigned char *) nlh + NLMSG_HDRLEN;
318 * nlmsg_len - length of message payload
319 * @nlh: netlink message header
321 static inline int nlmsg_len(const struct nlmsghdr *nlh)
323 return nlh->nlmsg_len - NLMSG_HDRLEN;
327 * nlmsg_attrdata - head of attributes data
328 * @nlh: netlink message header
329 * @hdrlen: length of family specific header
331 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
334 unsigned char *data = nlmsg_data(nlh);
335 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
339 * nlmsg_attrlen - length of attributes data
340 * @nlh: netlink message header
341 * @hdrlen: length of family specific header
343 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
345 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
349 * nlmsg_ok - check if the netlink message fits into the remaining bytes
350 * @nlh: netlink message header
351 * @remaining: number of bytes remaining in message stream
353 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
355 return (remaining >= (int) sizeof(struct nlmsghdr) &&
356 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
357 nlh->nlmsg_len <= remaining);
361 * nlmsg_next - next netlink message in message stream
362 * @nlh: netlink message header
363 * @remaining: number of bytes remaining in message stream
365 * Returns the next netlink message in the message stream and
366 * decrements remaining by the size of the current message.
368 static inline struct nlmsghdr *
369 nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
371 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
373 *remaining -= totlen;
375 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
379 * nlmsg_parse - parse attributes of a netlink message
380 * @nlh: netlink message header
381 * @hdrlen: length of family specific header
382 * @tb: destination array with maxtype+1 elements
383 * @maxtype: maximum attribute type to be expected
384 * @policy: validation policy
385 * @extack: extended ACK report struct
389 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
390 struct nlattr *tb[], int maxtype,
391 const struct nla_policy *policy,
392 struct netlink_ext_ack *extack)
394 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
397 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
398 nlmsg_attrlen(nlh, hdrlen), policy, extack);
402 * nlmsg_find_attr - find a specific attribute in a netlink message
403 * @nlh: netlink message header
404 * @hdrlen: length of familiy specific header
405 * @attrtype: type of attribute to look for
407 * Returns the first attribute which matches the specified type.
409 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
410 int hdrlen, int attrtype)
412 return nla_find(nlmsg_attrdata(nlh, hdrlen),
413 nlmsg_attrlen(nlh, hdrlen), attrtype);
417 * nlmsg_validate - validate a netlink message including attributes
418 * @nlh: netlinket message header
419 * @hdrlen: length of familiy specific header
420 * @maxtype: maximum attribute type to be expected
421 * @policy: validation policy
422 * @extack: extended ACK report struct
424 static inline int nlmsg_validate(const struct nlmsghdr *nlh,
425 int hdrlen, int maxtype,
426 const struct nla_policy *policy,
427 struct netlink_ext_ack *extack)
429 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
432 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
433 nlmsg_attrlen(nlh, hdrlen), maxtype, policy,
438 * nlmsg_report - need to report back to application?
439 * @nlh: netlink message header
441 * Returns 1 if a report back to the application is requested.
443 static inline int nlmsg_report(const struct nlmsghdr *nlh)
445 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
449 * nlmsg_for_each_attr - iterate over a stream of attributes
450 * @pos: loop counter, set to current attribute
451 * @nlh: netlink message header
452 * @hdrlen: length of familiy specific header
453 * @rem: initialized to len, holds bytes currently remaining in stream
455 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
456 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
457 nlmsg_attrlen(nlh, hdrlen), rem)
460 * nlmsg_put - Add a new netlink message to an skb
461 * @skb: socket buffer to store message in
462 * @portid: netlink PORTID of requesting application
463 * @seq: sequence number of message
464 * @type: message type
465 * @payload: length of message payload
466 * @flags: message flags
468 * Returns NULL if the tailroom of the skb is insufficient to store
469 * the message header and payload.
471 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
472 int type, int payload, int flags)
474 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
477 return __nlmsg_put(skb, portid, seq, type, payload, flags);
481 * nlmsg_put_answer - Add a new callback based netlink message to an skb
482 * @skb: socket buffer to store message in
483 * @cb: netlink callback
484 * @type: message type
485 * @payload: length of message payload
486 * @flags: message flags
488 * Returns NULL if the tailroom of the skb is insufficient to store
489 * the message header and payload.
491 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
492 struct netlink_callback *cb,
493 int type, int payload,
496 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
497 type, payload, flags);
501 * nlmsg_new - Allocate a new netlink message
502 * @payload: size of the message payload
503 * @flags: the type of memory to allocate.
505 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
506 * and a good default is needed.
508 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
510 return alloc_skb(nlmsg_total_size(payload), flags);
514 * nlmsg_end - Finalize a netlink message
515 * @skb: socket buffer the message is stored in
516 * @nlh: netlink message header
518 * Corrects the netlink message header to include the appeneded
519 * attributes. Only necessary if attributes have been added to
522 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
524 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
528 * nlmsg_get_pos - return current position in netlink message
529 * @skb: socket buffer the message is stored in
531 * Returns a pointer to the current tail of the message.
533 static inline void *nlmsg_get_pos(struct sk_buff *skb)
535 return skb_tail_pointer(skb);
539 * nlmsg_trim - Trim message to a mark
540 * @skb: socket buffer the message is stored in
541 * @mark: mark to trim to
543 * Trims the message to the provided mark.
545 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
548 WARN_ON((unsigned char *) mark < skb->data);
549 skb_trim(skb, (unsigned char *) mark - skb->data);
554 * nlmsg_cancel - Cancel construction of a netlink message
555 * @skb: socket buffer the message is stored in
556 * @nlh: netlink message header
558 * Removes the complete netlink message including all
559 * attributes from the socket buffer again.
561 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
563 nlmsg_trim(skb, nlh);
567 * nlmsg_free - free a netlink message
568 * @skb: socket buffer of netlink message
570 static inline void nlmsg_free(struct sk_buff *skb)
576 * nlmsg_multicast - multicast a netlink message
577 * @sk: netlink socket to spread messages to
578 * @skb: netlink message as socket buffer
579 * @portid: own netlink portid to avoid sending to yourself
580 * @group: multicast group id
581 * @flags: allocation flags
583 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
584 u32 portid, unsigned int group, gfp_t flags)
588 NETLINK_CB(skb).dst_group = group;
590 err = netlink_broadcast(sk, skb, portid, group, flags);
598 * nlmsg_unicast - unicast a netlink message
599 * @sk: netlink socket to spread message to
600 * @skb: netlink message as socket buffer
601 * @portid: netlink portid of the destination socket
603 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
607 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
615 * nlmsg_for_each_msg - iterate over a stream of messages
616 * @pos: loop counter, set to current message
617 * @head: head of message stream
618 * @len: length of message stream
619 * @rem: initialized to len, holds bytes currently remaining in stream
621 #define nlmsg_for_each_msg(pos, head, len, rem) \
622 for (pos = head, rem = len; \
623 nlmsg_ok(pos, rem); \
624 pos = nlmsg_next(pos, &(rem)))
627 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
628 * @cb: netlink callback structure that stores the sequence number
629 * @nlh: netlink message header to write the flag to
631 * This function checks if the sequence (generation) number changed during dump
632 * and if it did, advertises it in the netlink message header.
634 * The correct way to use it is to set cb->seq to the generation counter when
635 * all locks for dumping have been acquired, and then call this function for
636 * each message that is generated.
638 * Note that due to initialisation concerns, 0 is an invalid sequence number
639 * and must not be used by code that uses this functionality.
642 nl_dump_check_consistent(struct netlink_callback *cb,
643 struct nlmsghdr *nlh)
645 if (cb->prev_seq && cb->seq != cb->prev_seq)
646 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
647 cb->prev_seq = cb->seq;
650 /**************************************************************************
652 **************************************************************************/
655 * nla_attr_size - length of attribute not including padding
656 * @payload: length of payload
658 static inline int nla_attr_size(int payload)
660 return NLA_HDRLEN + payload;
664 * nla_total_size - total length of attribute including padding
665 * @payload: length of payload
667 static inline int nla_total_size(int payload)
669 return NLA_ALIGN(nla_attr_size(payload));
673 * nla_padlen - length of padding at the tail of attribute
674 * @payload: length of payload
676 static inline int nla_padlen(int payload)
678 return nla_total_size(payload) - nla_attr_size(payload);
682 * nla_type - attribute type
683 * @nla: netlink attribute
685 static inline int nla_type(const struct nlattr *nla)
687 return nla->nla_type & NLA_TYPE_MASK;
691 * nla_data - head of payload
692 * @nla: netlink attribute
694 static inline void *nla_data(const struct nlattr *nla)
696 return (char *) nla + NLA_HDRLEN;
700 * nla_len - length of payload
701 * @nla: netlink attribute
703 static inline int nla_len(const struct nlattr *nla)
705 return nla->nla_len - NLA_HDRLEN;
709 * nla_ok - check if the netlink attribute fits into the remaining bytes
710 * @nla: netlink attribute
711 * @remaining: number of bytes remaining in attribute stream
713 static inline int nla_ok(const struct nlattr *nla, int remaining)
715 return remaining >= (int) sizeof(*nla) &&
716 nla->nla_len >= sizeof(*nla) &&
717 nla->nla_len <= remaining;
721 * nla_next - next netlink attribute in attribute stream
722 * @nla: netlink attribute
723 * @remaining: number of bytes remaining in attribute stream
725 * Returns the next netlink attribute in the attribute stream and
726 * decrements remaining by the size of the current attribute.
728 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
730 unsigned int totlen = NLA_ALIGN(nla->nla_len);
732 *remaining -= totlen;
733 return (struct nlattr *) ((char *) nla + totlen);
737 * nla_find_nested - find attribute in a set of nested attributes
738 * @nla: attribute containing the nested attributes
739 * @attrtype: type of attribute to look for
741 * Returns the first attribute which matches the specified type.
743 static inline struct nlattr *
744 nla_find_nested(const struct nlattr *nla, int attrtype)
746 return nla_find(nla_data(nla), nla_len(nla), attrtype);
750 * nla_parse_nested - parse nested attributes
751 * @tb: destination array with maxtype+1 elements
752 * @maxtype: maximum attribute type to be expected
753 * @nla: attribute containing the nested attributes
754 * @policy: validation policy
755 * @extack: extended ACK report struct
759 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
760 const struct nlattr *nla,
761 const struct nla_policy *policy,
762 struct netlink_ext_ack *extack)
764 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
769 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
770 * @skb: socket buffer to add attribute to
771 * @attrtype: attribute type
772 * @value: numeric value
774 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
776 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
779 return nla_put(skb, attrtype, sizeof(u8), &tmp);
783 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
784 * @skb: socket buffer to add attribute to
785 * @attrtype: attribute type
786 * @value: numeric value
788 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
792 return nla_put(skb, attrtype, sizeof(u16), &tmp);
796 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
797 * @skb: socket buffer to add attribute to
798 * @attrtype: attribute type
799 * @value: numeric value
801 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
805 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
809 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
810 * @skb: socket buffer to add attribute to
811 * @attrtype: attribute type
812 * @value: numeric value
814 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
818 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
822 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
823 * @skb: socket buffer to add attribute to
824 * @attrtype: attribute type
825 * @value: numeric value
827 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
831 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
835 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
836 * @skb: socket buffer to add attribute to
837 * @attrtype: attribute type
838 * @value: numeric value
840 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
844 return nla_put(skb, attrtype, sizeof(u32), &tmp);
848 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
849 * @skb: socket buffer to add attribute to
850 * @attrtype: attribute type
851 * @value: numeric value
853 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
857 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
861 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
862 * @skb: socket buffer to add attribute to
863 * @attrtype: attribute type
864 * @value: numeric value
866 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
870 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
874 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
875 * @skb: socket buffer to add attribute to
876 * @attrtype: attribute type
877 * @value: numeric value
879 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
883 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
887 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
888 * @skb: socket buffer to add attribute to
889 * @attrtype: attribute type
890 * @value: numeric value
891 * @padattr: attribute type for the padding
893 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
894 u64 value, int padattr)
898 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
902 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
903 * @skb: socket buffer to add attribute to
904 * @attrtype: attribute type
905 * @value: numeric value
906 * @padattr: attribute type for the padding
908 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
913 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
917 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
918 * @skb: socket buffer to add attribute to
919 * @attrtype: attribute type
920 * @value: numeric value
921 * @padattr: attribute type for the padding
923 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
928 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
933 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
934 * @skb: socket buffer to add attribute to
935 * @attrtype: attribute type
936 * @value: numeric value
937 * @padattr: attribute type for the padding
939 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
944 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
948 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
949 * @skb: socket buffer to add attribute to
950 * @attrtype: attribute type
951 * @value: numeric value
953 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
957 return nla_put(skb, attrtype, sizeof(s8), &tmp);
961 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
962 * @skb: socket buffer to add attribute to
963 * @attrtype: attribute type
964 * @value: numeric value
966 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
970 return nla_put(skb, attrtype, sizeof(s16), &tmp);
974 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
975 * @skb: socket buffer to add attribute to
976 * @attrtype: attribute type
977 * @value: numeric value
979 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
983 return nla_put(skb, attrtype, sizeof(s32), &tmp);
987 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
988 * @skb: socket buffer to add attribute to
989 * @attrtype: attribute type
990 * @value: numeric value
991 * @padattr: attribute type for the padding
993 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
998 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1002 * nla_put_string - Add a string netlink attribute to a socket buffer
1003 * @skb: socket buffer to add attribute to
1004 * @attrtype: attribute type
1005 * @str: NUL terminated string
1007 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1010 return nla_put(skb, attrtype, strlen(str) + 1, str);
1014 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1015 * @skb: socket buffer to add attribute to
1016 * @attrtype: attribute type
1018 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1020 return nla_put(skb, attrtype, 0, NULL);
1024 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1025 * @skb: socket buffer to add attribute to
1026 * @attrtype: attribute type
1027 * @njiffies: number of jiffies to convert to msecs
1028 * @padattr: attribute type for the padding
1030 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1031 unsigned long njiffies, int padattr)
1033 u64 tmp = jiffies_to_msecs(njiffies);
1035 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1039 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1041 * @skb: socket buffer to add attribute to
1042 * @attrtype: attribute type
1043 * @addr: IPv4 address
1045 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1050 return nla_put_be32(skb, attrtype, tmp);
1054 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1056 * @skb: socket buffer to add attribute to
1057 * @attrtype: attribute type
1058 * @addr: IPv6 address
1060 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1061 const struct in6_addr *addr)
1063 return nla_put(skb, attrtype, sizeof(*addr), addr);
1067 * nla_get_u32 - return payload of u32 attribute
1068 * @nla: u32 netlink attribute
1070 static inline u32 nla_get_u32(const struct nlattr *nla)
1072 return *(u32 *) nla_data(nla);
1076 * nla_get_be32 - return payload of __be32 attribute
1077 * @nla: __be32 netlink attribute
1079 static inline __be32 nla_get_be32(const struct nlattr *nla)
1081 return *(__be32 *) nla_data(nla);
1085 * nla_get_le32 - return payload of __le32 attribute
1086 * @nla: __le32 netlink attribute
1088 static inline __le32 nla_get_le32(const struct nlattr *nla)
1090 return *(__le32 *) nla_data(nla);
1094 * nla_get_u16 - return payload of u16 attribute
1095 * @nla: u16 netlink attribute
1097 static inline u16 nla_get_u16(const struct nlattr *nla)
1099 return *(u16 *) nla_data(nla);
1103 * nla_get_be16 - return payload of __be16 attribute
1104 * @nla: __be16 netlink attribute
1106 static inline __be16 nla_get_be16(const struct nlattr *nla)
1108 return *(__be16 *) nla_data(nla);
1112 * nla_get_le16 - return payload of __le16 attribute
1113 * @nla: __le16 netlink attribute
1115 static inline __le16 nla_get_le16(const struct nlattr *nla)
1117 return *(__le16 *) nla_data(nla);
1121 * nla_get_u8 - return payload of u8 attribute
1122 * @nla: u8 netlink attribute
1124 static inline u8 nla_get_u8(const struct nlattr *nla)
1126 return *(u8 *) nla_data(nla);
1130 * nla_get_u64 - return payload of u64 attribute
1131 * @nla: u64 netlink attribute
1133 static inline u64 nla_get_u64(const struct nlattr *nla)
1137 nla_memcpy(&tmp, nla, sizeof(tmp));
1143 * nla_get_be64 - return payload of __be64 attribute
1144 * @nla: __be64 netlink attribute
1146 static inline __be64 nla_get_be64(const struct nlattr *nla)
1150 nla_memcpy(&tmp, nla, sizeof(tmp));
1156 * nla_get_le64 - return payload of __le64 attribute
1157 * @nla: __le64 netlink attribute
1159 static inline __le64 nla_get_le64(const struct nlattr *nla)
1161 return *(__le64 *) nla_data(nla);
1165 * nla_get_s32 - return payload of s32 attribute
1166 * @nla: s32 netlink attribute
1168 static inline s32 nla_get_s32(const struct nlattr *nla)
1170 return *(s32 *) nla_data(nla);
1174 * nla_get_s16 - return payload of s16 attribute
1175 * @nla: s16 netlink attribute
1177 static inline s16 nla_get_s16(const struct nlattr *nla)
1179 return *(s16 *) nla_data(nla);
1183 * nla_get_s8 - return payload of s8 attribute
1184 * @nla: s8 netlink attribute
1186 static inline s8 nla_get_s8(const struct nlattr *nla)
1188 return *(s8 *) nla_data(nla);
1192 * nla_get_s64 - return payload of s64 attribute
1193 * @nla: s64 netlink attribute
1195 static inline s64 nla_get_s64(const struct nlattr *nla)
1199 nla_memcpy(&tmp, nla, sizeof(tmp));
1205 * nla_get_flag - return payload of flag attribute
1206 * @nla: flag netlink attribute
1208 static inline int nla_get_flag(const struct nlattr *nla)
1214 * nla_get_msecs - return payload of msecs attribute
1215 * @nla: msecs netlink attribute
1217 * Returns the number of milliseconds in jiffies.
1219 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1221 u64 msecs = nla_get_u64(nla);
1223 return msecs_to_jiffies((unsigned long) msecs);
1227 * nla_get_in_addr - return payload of IPv4 address attribute
1228 * @nla: IPv4 address netlink attribute
1230 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1232 return *(__be32 *) nla_data(nla);
1236 * nla_get_in6_addr - return payload of IPv6 address attribute
1237 * @nla: IPv6 address netlink attribute
1239 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1241 struct in6_addr tmp;
1243 nla_memcpy(&tmp, nla, sizeof(tmp));
1248 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1249 * @nla: nla_bitfield32 attribute
1251 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1253 struct nla_bitfield32 tmp;
1255 nla_memcpy(&tmp, nla, sizeof(tmp));
1260 * nla_memdup - duplicate attribute memory (kmemdup)
1261 * @src: netlink attribute to duplicate from
1264 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1266 return kmemdup(nla_data(src), nla_len(src), gfp);
1270 * nla_nest_start - Start a new level of nested attributes
1271 * @skb: socket buffer to add attributes to
1272 * @attrtype: attribute type of container
1274 * Returns the container attribute
1276 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1278 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1280 if (nla_put(skb, attrtype, 0, NULL) < 0)
1287 * nla_nest_end - Finalize nesting of attributes
1288 * @skb: socket buffer the attributes are stored in
1289 * @start: container attribute
1291 * Corrects the container attribute header to include the all
1292 * appeneded attributes.
1294 * Returns the total data length of the skb.
1296 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1298 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1303 * nla_nest_cancel - Cancel nesting of attributes
1304 * @skb: socket buffer the message is stored in
1305 * @start: container attribute
1307 * Removes the container attribute and including all nested
1308 * attributes. Returns -EMSGSIZE
1310 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1312 nlmsg_trim(skb, start);
1316 * nla_validate_nested - Validate a stream of nested attributes
1317 * @start: container attribute
1318 * @maxtype: maximum attribute type to be expected
1319 * @policy: validation policy
1320 * @extack: extended ACK report struct
1322 * Validates all attributes in the nested attribute stream against the
1323 * specified policy. Attributes with a type exceeding maxtype will be
1324 * ignored. See documenation of struct nla_policy for more details.
1326 * Returns 0 on success or a negative error code.
1328 static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
1329 const struct nla_policy *policy,
1330 struct netlink_ext_ack *extack)
1332 return nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1337 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1338 * @skb: socket buffer the message is stored in
1340 * Return true if padding is needed to align the next attribute (nla_data()) to
1341 * a 64-bit aligned area.
1343 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1345 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1346 /* The nlattr header is 4 bytes in size, that's why we test
1347 * if the skb->data _is_ aligned. A NOP attribute, plus
1348 * nlattr header for next attribute, will make nla_data()
1351 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1358 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1359 * @skb: socket buffer the message is stored in
1360 * @padattr: attribute type for the padding
1362 * Conditionally emit a padding netlink attribute in order to make
1363 * the next attribute we emit have a 64-bit aligned nla_data() area.
1364 * This will only be done in architectures which do not have
1365 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1367 * Returns zero on success or a negative error code.
1369 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1371 if (nla_need_padding_for_64bit(skb) &&
1372 !nla_reserve(skb, padattr, 0))
1379 * nla_total_size_64bit - total length of attribute including padding
1380 * @payload: length of payload
1382 static inline int nla_total_size_64bit(int payload)
1384 return NLA_ALIGN(nla_attr_size(payload))
1385 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1386 + NLA_ALIGN(nla_attr_size(0))
1392 * nla_for_each_attr - iterate over a stream of attributes
1393 * @pos: loop counter, set to current attribute
1394 * @head: head of attribute stream
1395 * @len: length of attribute stream
1396 * @rem: initialized to len, holds bytes currently remaining in stream
1398 #define nla_for_each_attr(pos, head, len, rem) \
1399 for (pos = head, rem = len; \
1401 pos = nla_next(pos, &(rem)))
1404 * nla_for_each_nested - iterate over nested attributes
1405 * @pos: loop counter, set to current attribute
1406 * @nla: attribute containing the nested attributes
1407 * @rem: initialized to len, holds bytes currently remaining in stream
1409 #define nla_for_each_nested(pos, nla, rem) \
1410 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1413 * nla_is_last - Test if attribute is last in stream
1414 * @nla: attribute to test
1415 * @rem: bytes remaining in stream
1417 static inline bool nla_is_last(const struct nlattr *nla, int rem)
1419 return nla->nla_len == rem;