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1#ifndef __NET_NETLINK_H
2#define __NET_NETLINK_H
3
4#include <linux/types.h>
5#include <linux/netlink.h>
6#include <linux/jiffies.h>
7#include <linux/in6.h>
8
9/* ========================================================================
10 * Netlink Messages and Attributes Interface (As Seen On TV)
11 * ------------------------------------------------------------------------
12 * Messages Interface
13 * ------------------------------------------------------------------------
14 *
15 * Message Format:
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)-----------------------+
23 *
24 * Payload Format:
25 * <---------------------- nlmsg_len(nlh) --------------------->
26 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
27 * +----------------------+- - -+--------------------------------+
28 * | Family Header | Pad | Attributes |
29 * +----------------------+- - -+--------------------------------+
30 * nlmsg_attrdata(nlh, hdrlen)---^
31 *
32 * Data Structures:
33 * struct nlmsghdr netlink message header
34 *
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
44 *
45 * Message Sending:
46 * nlmsg_multicast() multicast message to several groups
47 * nlmsg_unicast() unicast a message to a single socket
48 * nlmsg_notify() send notification message
49 *
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
54 *
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
60 *
61 * Message Parsing:
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
69 *
70 * Misc:
71 * nlmsg_report() report back to application?
72 *
73 * ------------------------------------------------------------------------
74 * Attributes Interface
75 * ------------------------------------------------------------------------
76 *
77 * Attribute Format:
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)-----------------------------'
86 *
87 * Data Structures:
88 * struct nlattr netlink attribute header
89 *
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
96 *
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(skb, type, value) add u64 attribute to skb
102 * nla_put_s8(skb, type, value) add s8 attribute to skb
103 * nla_put_s16(skb, type, value) add s16 attribute to skb
104 * nla_put_s32(skb, type, value) add s32 attribute to skb
105 * nla_put_s64(skb, type, value) add s64 attribute to skb
106 * nla_put_string(skb, type, str) add string attribute to skb
107 * nla_put_flag(skb, type) add flag attribute to skb
108 * nla_put_msecs(skb, type, jiffies) add msecs attribute to skb
109 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb
110 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb
111 *
112 * Nested Attributes Construction:
113 * nla_nest_start(skb, type) start a nested attribute
114 * nla_nest_end(skb, nla) finalize a nested attribute
115 * nla_nest_cancel(skb, nla) cancel nested attribute construction
116 *
117 * Attribute Length Calculations:
118 * nla_attr_size(payload) length of attribute w/o padding
119 * nla_total_size(payload) length of attribute w/ padding
120 * nla_padlen(payload) length of padding
121 *
122 * Attribute Payload Access:
123 * nla_data(nla) head of attribute payload
124 * nla_len(nla) length of attribute payload
125 *
126 * Attribute Payload Access for Basic Types:
127 * nla_get_u8(nla) get payload for a u8 attribute
128 * nla_get_u16(nla) get payload for a u16 attribute
129 * nla_get_u32(nla) get payload for a u32 attribute
130 * nla_get_u64(nla) get payload for a u64 attribute
131 * nla_get_s8(nla) get payload for a s8 attribute
132 * nla_get_s16(nla) get payload for a s16 attribute
133 * nla_get_s32(nla) get payload for a s32 attribute
134 * nla_get_s64(nla) get payload for a s64 attribute
135 * nla_get_flag(nla) return 1 if flag is true
136 * nla_get_msecs(nla) get payload for a msecs attribute
137 *
138 * Attribute Misc:
139 * nla_memcpy(dest, nla, count) copy attribute into memory
140 * nla_memcmp(nla, data, size) compare attribute with memory area
141 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
142 * nla_strcmp(nla, str) compare attribute with string
143 *
144 * Attribute Parsing:
145 * nla_ok(nla, remaining) does nla fit into remaining bytes?
146 * nla_next(nla, remaining) get next netlink attribute
147 * nla_validate() validate a stream of attributes
148 * nla_validate_nested() validate a stream of nested attributes
149 * nla_find() find attribute in stream of attributes
150 * nla_find_nested() find attribute in nested attributes
151 * nla_parse() parse and validate stream of attrs
152 * nla_parse_nested() parse nested attribuets
153 * nla_for_each_attr() loop over all attributes
154 * nla_for_each_nested() loop over the nested attributes
155 *=========================================================================
156 */
157
158 /**
159 * Standard attribute types to specify validation policy
160 */
161enum {
162 NLA_UNSPEC,
163 NLA_U8,
164 NLA_U16,
165 NLA_U32,
166 NLA_U64,
167 NLA_STRING,
168 NLA_FLAG,
169 NLA_MSECS,
170 NLA_NESTED,
171 NLA_NESTED_COMPAT,
172 NLA_NUL_STRING,
173 NLA_BINARY,
174 NLA_S8,
175 NLA_S16,
176 NLA_S32,
177 NLA_S64,
178 __NLA_TYPE_MAX,
179};
180
181#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
182
183/**
184 * struct nla_policy - attribute validation policy
185 * @type: Type of attribute or NLA_UNSPEC
186 * @len: Type specific length of payload
187 *
188 * Policies are defined as arrays of this struct, the array must be
189 * accessible by attribute type up to the highest identifier to be expected.
190 *
191 * Meaning of `len' field:
192 * NLA_STRING Maximum length of string
193 * NLA_NUL_STRING Maximum length of string (excluding NUL)
194 * NLA_FLAG Unused
195 * NLA_BINARY Maximum length of attribute payload
196 * NLA_NESTED Don't use `len' field -- length verification is
197 * done by checking len of nested header (or empty)
198 * NLA_NESTED_COMPAT Minimum length of structure payload
199 * NLA_U8, NLA_U16,
200 * NLA_U32, NLA_U64,
201 * NLA_S8, NLA_S16,
202 * NLA_S32, NLA_S64,
203 * NLA_MSECS Leaving the length field zero will verify the
204 * given type fits, using it verifies minimum length
205 * just like "All other"
206 * All other Minimum length of attribute payload
207 *
208 * Example:
209 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
210 * [ATTR_FOO] = { .type = NLA_U16 },
211 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
212 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
213 * };
214 */
215struct nla_policy {
216 u16 type;
217 u16 len;
218};
219
220/**
221 * struct nl_info - netlink source information
222 * @nlh: Netlink message header of original request
223 * @portid: Netlink PORTID of requesting application
224 */
225struct nl_info {
226 struct nlmsghdr *nlh;
227 struct net *nl_net;
228 u32 portid;
229};
230
231int netlink_rcv_skb(struct sk_buff *skb,
232 int (*cb)(struct sk_buff *, struct nlmsghdr *));
233int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
234 unsigned int group, int report, gfp_t flags);
235
236int nla_validate(const struct nlattr *head, int len, int maxtype,
237 const struct nla_policy *policy);
238int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
239 int len, const struct nla_policy *policy);
240int nla_policy_len(const struct nla_policy *, int);
241struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
242size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
243int nla_memcpy(void *dest, const struct nlattr *src, int count);
244int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
245int nla_strcmp(const struct nlattr *nla, const char *str);
246struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
247void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
248struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
249void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
250void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
251 const void *data);
252void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
253int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
254int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
255int nla_append(struct sk_buff *skb, int attrlen, const void *data);
256
257/**************************************************************************
258 * Netlink Messages
259 **************************************************************************/
260
261/**
262 * nlmsg_msg_size - length of netlink message not including padding
263 * @payload: length of message payload
264 */
265static inline int nlmsg_msg_size(int payload)
266{
267 return NLMSG_HDRLEN + payload;
268}
269
270/**
271 * nlmsg_total_size - length of netlink message including padding
272 * @payload: length of message payload
273 */
274static inline int nlmsg_total_size(int payload)
275{
276 return NLMSG_ALIGN(nlmsg_msg_size(payload));
277}
278
279/**
280 * nlmsg_padlen - length of padding at the message's tail
281 * @payload: length of message payload
282 */
283static inline int nlmsg_padlen(int payload)
284{
285 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
286}
287
288/**
289 * nlmsg_data - head of message payload
290 * @nlh: netlink message header
291 */
292static inline void *nlmsg_data(const struct nlmsghdr *nlh)
293{
294 return (unsigned char *) nlh + NLMSG_HDRLEN;
295}
296
297/**
298 * nlmsg_len - length of message payload
299 * @nlh: netlink message header
300 */
301static inline int nlmsg_len(const struct nlmsghdr *nlh)
302{
303 return nlh->nlmsg_len - NLMSG_HDRLEN;
304}
305
306/**
307 * nlmsg_attrdata - head of attributes data
308 * @nlh: netlink message header
309 * @hdrlen: length of family specific header
310 */
311static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
312 int hdrlen)
313{
314 unsigned char *data = nlmsg_data(nlh);
315 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
316}
317
318/**
319 * nlmsg_attrlen - length of attributes data
320 * @nlh: netlink message header
321 * @hdrlen: length of family specific header
322 */
323static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
324{
325 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
326}
327
328/**
329 * nlmsg_ok - check if the netlink message fits into the remaining bytes
330 * @nlh: netlink message header
331 * @remaining: number of bytes remaining in message stream
332 */
333static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
334{
335 return (remaining >= (int) sizeof(struct nlmsghdr) &&
336 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
337 nlh->nlmsg_len <= remaining);
338}
339
340/**
341 * nlmsg_next - next netlink message in message stream
342 * @nlh: netlink message header
343 * @remaining: number of bytes remaining in message stream
344 *
345 * Returns the next netlink message in the message stream and
346 * decrements remaining by the size of the current message.
347 */
348static inline struct nlmsghdr *
349nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
350{
351 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
352
353 *remaining -= totlen;
354
355 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
356}
357
358/**
359 * nlmsg_parse - parse attributes of a netlink message
360 * @nlh: netlink message header
361 * @hdrlen: length of family specific header
362 * @tb: destination array with maxtype+1 elements
363 * @maxtype: maximum attribute type to be expected
364 * @policy: validation policy
365 *
366 * See nla_parse()
367 */
368static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
369 struct nlattr *tb[], int maxtype,
370 const struct nla_policy *policy)
371{
372 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
373 return -EINVAL;
374
375 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
376 nlmsg_attrlen(nlh, hdrlen), policy);
377}
378
379/**
380 * nlmsg_find_attr - find a specific attribute in a netlink message
381 * @nlh: netlink message header
382 * @hdrlen: length of familiy specific header
383 * @attrtype: type of attribute to look for
384 *
385 * Returns the first attribute which matches the specified type.
386 */
387static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
388 int hdrlen, int attrtype)
389{
390 return nla_find(nlmsg_attrdata(nlh, hdrlen),
391 nlmsg_attrlen(nlh, hdrlen), attrtype);
392}
393
394/**
395 * nlmsg_validate - validate a netlink message including attributes
396 * @nlh: netlinket message header
397 * @hdrlen: length of familiy specific header
398 * @maxtype: maximum attribute type to be expected
399 * @policy: validation policy
400 */
401static inline int nlmsg_validate(const struct nlmsghdr *nlh,
402 int hdrlen, int maxtype,
403 const struct nla_policy *policy)
404{
405 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
406 return -EINVAL;
407
408 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
409 nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
410}
411
412/**
413 * nlmsg_report - need to report back to application?
414 * @nlh: netlink message header
415 *
416 * Returns 1 if a report back to the application is requested.
417 */
418static inline int nlmsg_report(const struct nlmsghdr *nlh)
419{
420 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
421}
422
423/**
424 * nlmsg_for_each_attr - iterate over a stream of attributes
425 * @pos: loop counter, set to current attribute
426 * @nlh: netlink message header
427 * @hdrlen: length of familiy specific header
428 * @rem: initialized to len, holds bytes currently remaining in stream
429 */
430#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
431 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
432 nlmsg_attrlen(nlh, hdrlen), rem)
433
434/**
435 * nlmsg_put - Add a new netlink message to an skb
436 * @skb: socket buffer to store message in
437 * @portid: netlink PORTID of requesting application
438 * @seq: sequence number of message
439 * @type: message type
440 * @payload: length of message payload
441 * @flags: message flags
442 *
443 * Returns NULL if the tailroom of the skb is insufficient to store
444 * the message header and payload.
445 */
446static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
447 int type, int payload, int flags)
448{
449 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
450 return NULL;
451
452 return __nlmsg_put(skb, portid, seq, type, payload, flags);
453}
454
455/**
456 * nlmsg_put_answer - Add a new callback based netlink message to an skb
457 * @skb: socket buffer to store message in
458 * @cb: netlink callback
459 * @type: message type
460 * @payload: length of message payload
461 * @flags: message flags
462 *
463 * Returns NULL if the tailroom of the skb is insufficient to store
464 * the message header and payload.
465 */
466static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
467 struct netlink_callback *cb,
468 int type, int payload,
469 int flags)
470{
471 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
472 type, payload, flags);
473}
474
475/**
476 * nlmsg_new - Allocate a new netlink message
477 * @payload: size of the message payload
478 * @flags: the type of memory to allocate.
479 *
480 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
481 * and a good default is needed.
482 */
483static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
484{
485 return alloc_skb(nlmsg_total_size(payload), flags);
486}
487
488/**
489 * nlmsg_end - Finalize a netlink message
490 * @skb: socket buffer the message is stored in
491 * @nlh: netlink message header
492 *
493 * Corrects the netlink message header to include the appeneded
494 * attributes. Only necessary if attributes have been added to
495 * the message.
496 */
497static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
498{
499 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
500}
501
502/**
503 * nlmsg_get_pos - return current position in netlink message
504 * @skb: socket buffer the message is stored in
505 *
506 * Returns a pointer to the current tail of the message.
507 */
508static inline void *nlmsg_get_pos(struct sk_buff *skb)
509{
510 return skb_tail_pointer(skb);
511}
512
513/**
514 * nlmsg_trim - Trim message to a mark
515 * @skb: socket buffer the message is stored in
516 * @mark: mark to trim to
517 *
518 * Trims the message to the provided mark.
519 */
520static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
521{
522 if (mark) {
523 WARN_ON((unsigned char *) mark < skb->data);
524 skb_trim(skb, (unsigned char *) mark - skb->data);
525 }
526}
527
528/**
529 * nlmsg_cancel - Cancel construction of a netlink message
530 * @skb: socket buffer the message is stored in
531 * @nlh: netlink message header
532 *
533 * Removes the complete netlink message including all
534 * attributes from the socket buffer again.
535 */
536static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
537{
538 nlmsg_trim(skb, nlh);
539}
540
541/**
542 * nlmsg_free - free a netlink message
543 * @skb: socket buffer of netlink message
544 */
545static inline void nlmsg_free(struct sk_buff *skb)
546{
547 kfree_skb(skb);
548}
549
550/**
551 * nlmsg_multicast - multicast a netlink message
552 * @sk: netlink socket to spread messages to
553 * @skb: netlink message as socket buffer
554 * @portid: own netlink portid to avoid sending to yourself
555 * @group: multicast group id
556 * @flags: allocation flags
557 */
558static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
559 u32 portid, unsigned int group, gfp_t flags)
560{
561 int err;
562
563 NETLINK_CB(skb).dst_group = group;
564
565 err = netlink_broadcast(sk, skb, portid, group, flags);
566 if (err > 0)
567 err = 0;
568
569 return err;
570}
571
572/**
573 * nlmsg_unicast - unicast a netlink message
574 * @sk: netlink socket to spread message to
575 * @skb: netlink message as socket buffer
576 * @portid: netlink portid of the destination socket
577 */
578static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
579{
580 int err;
581
582 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
583 if (err > 0)
584 err = 0;
585
586 return err;
587}
588
589/**
590 * nlmsg_for_each_msg - iterate over a stream of messages
591 * @pos: loop counter, set to current message
592 * @head: head of message stream
593 * @len: length of message stream
594 * @rem: initialized to len, holds bytes currently remaining in stream
595 */
596#define nlmsg_for_each_msg(pos, head, len, rem) \
597 for (pos = head, rem = len; \
598 nlmsg_ok(pos, rem); \
599 pos = nlmsg_next(pos, &(rem)))
600
601/**
602 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
603 * @cb: netlink callback structure that stores the sequence number
604 * @nlh: netlink message header to write the flag to
605 *
606 * This function checks if the sequence (generation) number changed during dump
607 * and if it did, advertises it in the netlink message header.
608 *
609 * The correct way to use it is to set cb->seq to the generation counter when
610 * all locks for dumping have been acquired, and then call this function for
611 * each message that is generated.
612 *
613 * Note that due to initialisation concerns, 0 is an invalid sequence number
614 * and must not be used by code that uses this functionality.
615 */
616static inline void
617nl_dump_check_consistent(struct netlink_callback *cb,
618 struct nlmsghdr *nlh)
619{
620 if (cb->prev_seq && cb->seq != cb->prev_seq)
621 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
622 cb->prev_seq = cb->seq;
623}
624
625/**************************************************************************
626 * Netlink Attributes
627 **************************************************************************/
628
629/**
630 * nla_attr_size - length of attribute not including padding
631 * @payload: length of payload
632 */
633static inline int nla_attr_size(int payload)
634{
635 return NLA_HDRLEN + payload;
636}
637
638/**
639 * nla_total_size - total length of attribute including padding
640 * @payload: length of payload
641 */
642static inline int nla_total_size(int payload)
643{
644 return NLA_ALIGN(nla_attr_size(payload));
645}
646
647/**
648 * nla_padlen - length of padding at the tail of attribute
649 * @payload: length of payload
650 */
651static inline int nla_padlen(int payload)
652{
653 return nla_total_size(payload) - nla_attr_size(payload);
654}
655
656/**
657 * nla_type - attribute type
658 * @nla: netlink attribute
659 */
660static inline int nla_type(const struct nlattr *nla)
661{
662 return nla->nla_type & NLA_TYPE_MASK;
663}
664
665/**
666 * nla_data - head of payload
667 * @nla: netlink attribute
668 */
669static inline void *nla_data(const struct nlattr *nla)
670{
671 return (char *) nla + NLA_HDRLEN;
672}
673
674/**
675 * nla_len - length of payload
676 * @nla: netlink attribute
677 */
678static inline int nla_len(const struct nlattr *nla)
679{
680 return nla->nla_len - NLA_HDRLEN;
681}
682
683/**
684 * nla_ok - check if the netlink attribute fits into the remaining bytes
685 * @nla: netlink attribute
686 * @remaining: number of bytes remaining in attribute stream
687 */
688static inline int nla_ok(const struct nlattr *nla, int remaining)
689{
690 return remaining >= (int) sizeof(*nla) &&
691 nla->nla_len >= sizeof(*nla) &&
692 nla->nla_len <= remaining;
693}
694
695/**
696 * nla_next - next netlink attribute in attribute stream
697 * @nla: netlink attribute
698 * @remaining: number of bytes remaining in attribute stream
699 *
700 * Returns the next netlink attribute in the attribute stream and
701 * decrements remaining by the size of the current attribute.
702 */
703static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
704{
705 int totlen = NLA_ALIGN(nla->nla_len);
706
707 *remaining -= totlen;
708 return (struct nlattr *) ((char *) nla + totlen);
709}
710
711/**
712 * nla_find_nested - find attribute in a set of nested attributes
713 * @nla: attribute containing the nested attributes
714 * @attrtype: type of attribute to look for
715 *
716 * Returns the first attribute which matches the specified type.
717 */
718static inline struct nlattr *
719nla_find_nested(const struct nlattr *nla, int attrtype)
720{
721 return nla_find(nla_data(nla), nla_len(nla), attrtype);
722}
723
724/**
725 * nla_parse_nested - parse nested attributes
726 * @tb: destination array with maxtype+1 elements
727 * @maxtype: maximum attribute type to be expected
728 * @nla: attribute containing the nested attributes
729 * @policy: validation policy
730 *
731 * See nla_parse()
732 */
733static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
734 const struct nlattr *nla,
735 const struct nla_policy *policy)
736{
737 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
738}
739
740/**
741 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
742 * @skb: socket buffer to add attribute to
743 * @attrtype: attribute type
744 * @value: numeric value
745 */
746static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
747{
748 return nla_put(skb, attrtype, sizeof(u8), &value);
749}
750
751/**
752 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
753 * @skb: socket buffer to add attribute to
754 * @attrtype: attribute type
755 * @value: numeric value
756 */
757static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
758{
759 return nla_put(skb, attrtype, sizeof(u16), &value);
760}
761
762/**
763 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
764 * @skb: socket buffer to add attribute to
765 * @attrtype: attribute type
766 * @value: numeric value
767 */
768static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
769{
770 return nla_put(skb, attrtype, sizeof(__be16), &value);
771}
772
773/**
774 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
775 * @skb: socket buffer to add attribute to
776 * @attrtype: attribute type
777 * @value: numeric value
778 */
779static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
780{
781 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, value);
782}
783
784/**
785 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
786 * @skb: socket buffer to add attribute to
787 * @attrtype: attribute type
788 * @value: numeric value
789 */
790static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
791{
792 return nla_put(skb, attrtype, sizeof(__le16), &value);
793}
794
795/**
796 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
797 * @skb: socket buffer to add attribute to
798 * @attrtype: attribute type
799 * @value: numeric value
800 */
801static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
802{
803 return nla_put(skb, attrtype, sizeof(u32), &value);
804}
805
806/**
807 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
808 * @skb: socket buffer to add attribute to
809 * @attrtype: attribute type
810 * @value: numeric value
811 */
812static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
813{
814 return nla_put(skb, attrtype, sizeof(__be32), &value);
815}
816
817/**
818 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
819 * @skb: socket buffer to add attribute to
820 * @attrtype: attribute type
821 * @value: numeric value
822 */
823static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
824{
825 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, value);
826}
827
828/**
829 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
830 * @skb: socket buffer to add attribute to
831 * @attrtype: attribute type
832 * @value: numeric value
833 */
834static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
835{
836 return nla_put(skb, attrtype, sizeof(__le32), &value);
837}
838
839/**
840 * nla_put_u64 - Add a u64 netlink attribute to a socket buffer
841 * @skb: socket buffer to add attribute to
842 * @attrtype: attribute type
843 * @value: numeric value
844 */
845static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
846{
847 return nla_put(skb, attrtype, sizeof(u64), &value);
848}
849
850/**
851 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer
852 * @skb: socket buffer to add attribute to
853 * @attrtype: attribute type
854 * @value: numeric value
855 */
856static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value)
857{
858 return nla_put(skb, attrtype, sizeof(__be64), &value);
859}
860
861/**
862 * nla_put_net64 - Add 64-bit network byte order netlink attribute to a socket buffer
863 * @skb: socket buffer to add attribute to
864 * @attrtype: attribute type
865 * @value: numeric value
866 */
867static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value)
868{
869 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, value);
870}
871
872/**
873 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer
874 * @skb: socket buffer to add attribute to
875 * @attrtype: attribute type
876 * @value: numeric value
877 */
878static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value)
879{
880 return nla_put(skb, attrtype, sizeof(__le64), &value);
881}
882
883/**
884 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
885 * @skb: socket buffer to add attribute to
886 * @attrtype: attribute type
887 * @value: numeric value
888 */
889static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
890{
891 return nla_put(skb, attrtype, sizeof(s8), &value);
892}
893
894/**
895 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
896 * @skb: socket buffer to add attribute to
897 * @attrtype: attribute type
898 * @value: numeric value
899 */
900static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
901{
902 return nla_put(skb, attrtype, sizeof(s16), &value);
903}
904
905/**
906 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
907 * @skb: socket buffer to add attribute to
908 * @attrtype: attribute type
909 * @value: numeric value
910 */
911static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
912{
913 return nla_put(skb, attrtype, sizeof(s32), &value);
914}
915
916/**
917 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer
918 * @skb: socket buffer to add attribute to
919 * @attrtype: attribute type
920 * @value: numeric value
921 */
922static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value)
923{
924 return nla_put(skb, attrtype, sizeof(s64), &value);
925}
926
927/**
928 * nla_put_string - Add a string netlink attribute to a socket buffer
929 * @skb: socket buffer to add attribute to
930 * @attrtype: attribute type
931 * @str: NUL terminated string
932 */
933static inline int nla_put_string(struct sk_buff *skb, int attrtype,
934 const char *str)
935{
936 return nla_put(skb, attrtype, strlen(str) + 1, str);
937}
938
939/**
940 * nla_put_flag - Add a flag netlink attribute to a socket buffer
941 * @skb: socket buffer to add attribute to
942 * @attrtype: attribute type
943 */
944static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
945{
946 return nla_put(skb, attrtype, 0, NULL);
947}
948
949/**
950 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer
951 * @skb: socket buffer to add attribute to
952 * @attrtype: attribute type
953 * @njiffies: number of jiffies to convert to msecs
954 */
955static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
956 unsigned long njiffies)
957{
958 u64 tmp = jiffies_to_msecs(njiffies);
959 return nla_put(skb, attrtype, sizeof(u64), &tmp);
960}
961
962/**
963 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
964 * buffer
965 * @skb: socket buffer to add attribute to
966 * @attrtype: attribute type
967 * @addr: IPv4 address
968 */
969static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
970 __be32 addr)
971{
972 return nla_put_be32(skb, attrtype, addr);
973}
974
975/**
976 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
977 * buffer
978 * @skb: socket buffer to add attribute to
979 * @attrtype: attribute type
980 * @addr: IPv6 address
981 */
982static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
983 const struct in6_addr *addr)
984{
985 return nla_put(skb, attrtype, sizeof(*addr), addr);
986}
987
988/**
989 * nla_get_u32 - return payload of u32 attribute
990 * @nla: u32 netlink attribute
991 */
992static inline u32 nla_get_u32(const struct nlattr *nla)
993{
994 return *(u32 *) nla_data(nla);
995}
996
997/**
998 * nla_get_be32 - return payload of __be32 attribute
999 * @nla: __be32 netlink attribute
1000 */
1001static inline __be32 nla_get_be32(const struct nlattr *nla)
1002{
1003 return *(__be32 *) nla_data(nla);
1004}
1005
1006/**
1007 * nla_get_le32 - return payload of __le32 attribute
1008 * @nla: __le32 netlink attribute
1009 */
1010static inline __le32 nla_get_le32(const struct nlattr *nla)
1011{
1012 return *(__le32 *) nla_data(nla);
1013}
1014
1015/**
1016 * nla_get_u16 - return payload of u16 attribute
1017 * @nla: u16 netlink attribute
1018 */
1019static inline u16 nla_get_u16(const struct nlattr *nla)
1020{
1021 return *(u16 *) nla_data(nla);
1022}
1023
1024/**
1025 * nla_get_be16 - return payload of __be16 attribute
1026 * @nla: __be16 netlink attribute
1027 */
1028static inline __be16 nla_get_be16(const struct nlattr *nla)
1029{
1030 return *(__be16 *) nla_data(nla);
1031}
1032
1033/**
1034 * nla_get_le16 - return payload of __le16 attribute
1035 * @nla: __le16 netlink attribute
1036 */
1037static inline __le16 nla_get_le16(const struct nlattr *nla)
1038{
1039 return *(__le16 *) nla_data(nla);
1040}
1041
1042/**
1043 * nla_get_u8 - return payload of u8 attribute
1044 * @nla: u8 netlink attribute
1045 */
1046static inline u8 nla_get_u8(const struct nlattr *nla)
1047{
1048 return *(u8 *) nla_data(nla);
1049}
1050
1051/**
1052 * nla_get_u64 - return payload of u64 attribute
1053 * @nla: u64 netlink attribute
1054 */
1055static inline u64 nla_get_u64(const struct nlattr *nla)
1056{
1057 u64 tmp;
1058
1059 nla_memcpy(&tmp, nla, sizeof(tmp));
1060
1061 return tmp;
1062}
1063
1064/**
1065 * nla_get_be64 - return payload of __be64 attribute
1066 * @nla: __be64 netlink attribute
1067 */
1068static inline __be64 nla_get_be64(const struct nlattr *nla)
1069{
1070 __be64 tmp;
1071
1072 nla_memcpy(&tmp, nla, sizeof(tmp));
1073
1074 return tmp;
1075}
1076
1077/**
1078 * nla_get_le64 - return payload of __le64 attribute
1079 * @nla: __le64 netlink attribute
1080 */
1081static inline __le64 nla_get_le64(const struct nlattr *nla)
1082{
1083 return *(__le64 *) nla_data(nla);
1084}
1085
1086/**
1087 * nla_get_s32 - return payload of s32 attribute
1088 * @nla: s32 netlink attribute
1089 */
1090static inline s32 nla_get_s32(const struct nlattr *nla)
1091{
1092 return *(s32 *) nla_data(nla);
1093}
1094
1095/**
1096 * nla_get_s16 - return payload of s16 attribute
1097 * @nla: s16 netlink attribute
1098 */
1099static inline s16 nla_get_s16(const struct nlattr *nla)
1100{
1101 return *(s16 *) nla_data(nla);
1102}
1103
1104/**
1105 * nla_get_s8 - return payload of s8 attribute
1106 * @nla: s8 netlink attribute
1107 */
1108static inline s8 nla_get_s8(const struct nlattr *nla)
1109{
1110 return *(s8 *) nla_data(nla);
1111}
1112
1113/**
1114 * nla_get_s64 - return payload of s64 attribute
1115 * @nla: s64 netlink attribute
1116 */
1117static inline s64 nla_get_s64(const struct nlattr *nla)
1118{
1119 s64 tmp;
1120
1121 nla_memcpy(&tmp, nla, sizeof(tmp));
1122
1123 return tmp;
1124}
1125
1126/**
1127 * nla_get_flag - return payload of flag attribute
1128 * @nla: flag netlink attribute
1129 */
1130static inline int nla_get_flag(const struct nlattr *nla)
1131{
1132 return !!nla;
1133}
1134
1135/**
1136 * nla_get_msecs - return payload of msecs attribute
1137 * @nla: msecs netlink attribute
1138 *
1139 * Returns the number of milliseconds in jiffies.
1140 */
1141static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1142{
1143 u64 msecs = nla_get_u64(nla);
1144
1145 return msecs_to_jiffies((unsigned long) msecs);
1146}
1147
1148/**
1149 * nla_get_in_addr - return payload of IPv4 address attribute
1150 * @nla: IPv4 address netlink attribute
1151 */
1152static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1153{
1154 return *(__be32 *) nla_data(nla);
1155}
1156
1157/**
1158 * nla_get_in6_addr - return payload of IPv6 address attribute
1159 * @nla: IPv6 address netlink attribute
1160 */
1161static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1162{
1163 struct in6_addr tmp;
1164
1165 nla_memcpy(&tmp, nla, sizeof(tmp));
1166 return tmp;
1167}
1168
1169/**
1170 * nla_nest_start - Start a new level of nested attributes
1171 * @skb: socket buffer to add attributes to
1172 * @attrtype: attribute type of container
1173 *
1174 * Returns the container attribute
1175 */
1176static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1177{
1178 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1179
1180 if (nla_put(skb, attrtype, 0, NULL) < 0)
1181 return NULL;
1182
1183 return start;
1184}
1185
1186/**
1187 * nla_nest_end - Finalize nesting of attributes
1188 * @skb: socket buffer the attributes are stored in
1189 * @start: container attribute
1190 *
1191 * Corrects the container attribute header to include the all
1192 * appeneded attributes.
1193 *
1194 * Returns the total data length of the skb.
1195 */
1196static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1197{
1198 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1199 return skb->len;
1200}
1201
1202/**
1203 * nla_nest_cancel - Cancel nesting of attributes
1204 * @skb: socket buffer the message is stored in
1205 * @start: container attribute
1206 *
1207 * Removes the container attribute and including all nested
1208 * attributes. Returns -EMSGSIZE
1209 */
1210static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1211{
1212 nlmsg_trim(skb, start);
1213}
1214
1215/**
1216 * nla_validate_nested - Validate a stream of nested attributes
1217 * @start: container attribute
1218 * @maxtype: maximum attribute type to be expected
1219 * @policy: validation policy
1220 *
1221 * Validates all attributes in the nested attribute stream against the
1222 * specified policy. Attributes with a type exceeding maxtype will be
1223 * ignored. See documenation of struct nla_policy for more details.
1224 *
1225 * Returns 0 on success or a negative error code.
1226 */
1227static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
1228 const struct nla_policy *policy)
1229{
1230 return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
1231}
1232
1233/**
1234 * nla_for_each_attr - iterate over a stream of attributes
1235 * @pos: loop counter, set to current attribute
1236 * @head: head of attribute stream
1237 * @len: length of attribute stream
1238 * @rem: initialized to len, holds bytes currently remaining in stream
1239 */
1240#define nla_for_each_attr(pos, head, len, rem) \
1241 for (pos = head, rem = len; \
1242 nla_ok(pos, rem); \
1243 pos = nla_next(pos, &(rem)))
1244
1245/**
1246 * nla_for_each_nested - iterate over nested attributes
1247 * @pos: loop counter, set to current attribute
1248 * @nla: attribute containing the nested attributes
1249 * @rem: initialized to len, holds bytes currently remaining in stream
1250 */
1251#define nla_for_each_nested(pos, nla, rem) \
1252 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1253
1254/**
1255 * nla_is_last - Test if attribute is last in stream
1256 * @nla: attribute to test
1257 * @rem: bytes remaining in stream
1258 */
1259static inline bool nla_is_last(const struct nlattr *nla, int rem)
1260{
1261 return nla->nla_len == rem;
1262}
1263
1264#endif
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __NET_NETLINK_H
3#define __NET_NETLINK_H
4
5#include <linux/types.h>
6#include <linux/netlink.h>
7#include <linux/jiffies.h>
8#include <linux/in6.h>
9
10/* ========================================================================
11 * Netlink Messages and Attributes Interface (As Seen On TV)
12 * ------------------------------------------------------------------------
13 * Messages Interface
14 * ------------------------------------------------------------------------
15 *
16 * Message Format:
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)-----------------------+
24 *
25 * Payload Format:
26 * <---------------------- nlmsg_len(nlh) --------------------->
27 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
28 * +----------------------+- - -+--------------------------------+
29 * | Family Header | Pad | Attributes |
30 * +----------------------+- - -+--------------------------------+
31 * nlmsg_attrdata(nlh, hdrlen)---^
32 *
33 * Data Structures:
34 * struct nlmsghdr netlink message header
35 *
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
45 *
46 * Message Sending:
47 * nlmsg_multicast() multicast message to several groups
48 * nlmsg_unicast() unicast a message to a single socket
49 * nlmsg_notify() send notification message
50 *
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
55 *
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
61 *
62 * Message Parsing:
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
70 *
71 * Misc:
72 * nlmsg_report() report back to application?
73 *
74 * ------------------------------------------------------------------------
75 * Attributes Interface
76 * ------------------------------------------------------------------------
77 *
78 * Attribute Format:
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)-----------------------------'
87 *
88 * Data Structures:
89 * struct nlattr netlink attribute header
90 *
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
97 *
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
115 *
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
120 *
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
125 *
126 * Attribute Payload Access:
127 * nla_data(nla) head of attribute payload
128 * nla_len(nla) length of attribute payload
129 *
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
141 *
142 * Attribute Misc:
143 * nla_memcpy(dest, nla, count) copy attribute into memory
144 * nla_memcmp(nla, data, size) compare attribute with memory area
145 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
146 * nla_strcmp(nla, str) compare attribute with string
147 *
148 * Attribute Parsing:
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 attribuets
157 * nla_for_each_attr() loop over all attributes
158 * nla_for_each_nested() loop over the nested attributes
159 *=========================================================================
160 */
161
162 /**
163 * Standard attribute types to specify validation policy
164 */
165enum {
166 NLA_UNSPEC,
167 NLA_U8,
168 NLA_U16,
169 NLA_U32,
170 NLA_U64,
171 NLA_STRING,
172 NLA_FLAG,
173 NLA_MSECS,
174 NLA_NESTED,
175 NLA_NESTED_COMPAT,
176 NLA_NUL_STRING,
177 NLA_BINARY,
178 NLA_S8,
179 NLA_S16,
180 NLA_S32,
181 NLA_S64,
182 NLA_BITFIELD32,
183 __NLA_TYPE_MAX,
184};
185
186#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
187
188/**
189 * struct nla_policy - attribute validation policy
190 * @type: Type of attribute or NLA_UNSPEC
191 * @len: Type specific length of payload
192 *
193 * Policies are defined as arrays of this struct, the array must be
194 * accessible by attribute type up to the highest identifier to be expected.
195 *
196 * Meaning of `len' field:
197 * NLA_STRING Maximum length of string
198 * NLA_NUL_STRING Maximum length of string (excluding NUL)
199 * NLA_FLAG Unused
200 * NLA_BINARY Maximum length of attribute payload
201 * NLA_NESTED Don't use `len' field -- length verification is
202 * done by checking len of nested header (or empty)
203 * NLA_NESTED_COMPAT Minimum length of structure payload
204 * NLA_U8, NLA_U16,
205 * NLA_U32, NLA_U64,
206 * NLA_S8, NLA_S16,
207 * NLA_S32, NLA_S64,
208 * NLA_MSECS Leaving the length field zero will verify the
209 * given type fits, using it verifies minimum length
210 * just like "All other"
211 * NLA_BITFIELD32 A 32-bit bitmap/bitselector attribute
212 * All other Minimum length of attribute payload
213 *
214 * Example:
215 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
216 * [ATTR_FOO] = { .type = NLA_U16 },
217 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
218 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
219 * [ATTR_GOO] = { .type = NLA_BITFIELD32, .validation_data = &myvalidflags },
220 * };
221 */
222struct nla_policy {
223 u16 type;
224 u16 len;
225 void *validation_data;
226};
227
228/**
229 * struct nl_info - netlink source information
230 * @nlh: Netlink message header of original request
231 * @portid: Netlink PORTID of requesting application
232 */
233struct nl_info {
234 struct nlmsghdr *nlh;
235 struct net *nl_net;
236 u32 portid;
237 bool skip_notify;
238};
239
240int netlink_rcv_skb(struct sk_buff *skb,
241 int (*cb)(struct sk_buff *, struct nlmsghdr *,
242 struct netlink_ext_ack *));
243int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
244 unsigned int group, int report, gfp_t flags);
245
246int nla_validate(const struct nlattr *head, int len, int maxtype,
247 const struct nla_policy *policy,
248 struct netlink_ext_ack *extack);
249int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
250 int len, const struct nla_policy *policy,
251 struct netlink_ext_ack *extack);
252int nla_policy_len(const struct nla_policy *, int);
253struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
254size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
255char *nla_strdup(const struct nlattr *nla, gfp_t flags);
256int nla_memcpy(void *dest, const struct nlattr *src, int count);
257int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
258int nla_strcmp(const struct nlattr *nla, const char *str);
259struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
260struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
261 int attrlen, int padattr);
262void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
263struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
264struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
265 int attrlen, int padattr);
266void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
267void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
268 const void *data);
269void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
270 const void *data, int padattr);
271void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
272int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
273int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
274 const void *data, int padattr);
275int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
276int nla_append(struct sk_buff *skb, int attrlen, const void *data);
277
278/**************************************************************************
279 * Netlink Messages
280 **************************************************************************/
281
282/**
283 * nlmsg_msg_size - length of netlink message not including padding
284 * @payload: length of message payload
285 */
286static inline int nlmsg_msg_size(int payload)
287{
288 return NLMSG_HDRLEN + payload;
289}
290
291/**
292 * nlmsg_total_size - length of netlink message including padding
293 * @payload: length of message payload
294 */
295static inline int nlmsg_total_size(int payload)
296{
297 return NLMSG_ALIGN(nlmsg_msg_size(payload));
298}
299
300/**
301 * nlmsg_padlen - length of padding at the message's tail
302 * @payload: length of message payload
303 */
304static inline int nlmsg_padlen(int payload)
305{
306 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
307}
308
309/**
310 * nlmsg_data - head of message payload
311 * @nlh: netlink message header
312 */
313static inline void *nlmsg_data(const struct nlmsghdr *nlh)
314{
315 return (unsigned char *) nlh + NLMSG_HDRLEN;
316}
317
318/**
319 * nlmsg_len - length of message payload
320 * @nlh: netlink message header
321 */
322static inline int nlmsg_len(const struct nlmsghdr *nlh)
323{
324 return nlh->nlmsg_len - NLMSG_HDRLEN;
325}
326
327/**
328 * nlmsg_attrdata - head of attributes data
329 * @nlh: netlink message header
330 * @hdrlen: length of family specific header
331 */
332static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
333 int hdrlen)
334{
335 unsigned char *data = nlmsg_data(nlh);
336 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
337}
338
339/**
340 * nlmsg_attrlen - length of attributes data
341 * @nlh: netlink message header
342 * @hdrlen: length of family specific header
343 */
344static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
345{
346 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
347}
348
349/**
350 * nlmsg_ok - check if the netlink message fits into the remaining bytes
351 * @nlh: netlink message header
352 * @remaining: number of bytes remaining in message stream
353 */
354static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
355{
356 return (remaining >= (int) sizeof(struct nlmsghdr) &&
357 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
358 nlh->nlmsg_len <= remaining);
359}
360
361/**
362 * nlmsg_next - next netlink message in message stream
363 * @nlh: netlink message header
364 * @remaining: number of bytes remaining in message stream
365 *
366 * Returns the next netlink message in the message stream and
367 * decrements remaining by the size of the current message.
368 */
369static inline struct nlmsghdr *
370nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
371{
372 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
373
374 *remaining -= totlen;
375
376 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
377}
378
379/**
380 * nlmsg_parse - parse attributes of a netlink message
381 * @nlh: netlink message header
382 * @hdrlen: length of family specific header
383 * @tb: destination array with maxtype+1 elements
384 * @maxtype: maximum attribute type to be expected
385 * @policy: validation policy
386 * @extack: extended ACK report struct
387 *
388 * See nla_parse()
389 */
390static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
391 struct nlattr *tb[], int maxtype,
392 const struct nla_policy *policy,
393 struct netlink_ext_ack *extack)
394{
395 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
396 return -EINVAL;
397
398 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
399 nlmsg_attrlen(nlh, hdrlen), policy, extack);
400}
401
402/**
403 * nlmsg_find_attr - find a specific attribute in a netlink message
404 * @nlh: netlink message header
405 * @hdrlen: length of familiy specific header
406 * @attrtype: type of attribute to look for
407 *
408 * Returns the first attribute which matches the specified type.
409 */
410static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
411 int hdrlen, int attrtype)
412{
413 return nla_find(nlmsg_attrdata(nlh, hdrlen),
414 nlmsg_attrlen(nlh, hdrlen), attrtype);
415}
416
417/**
418 * nlmsg_validate - validate a netlink message including attributes
419 * @nlh: netlinket message header
420 * @hdrlen: length of familiy specific header
421 * @maxtype: maximum attribute type to be expected
422 * @policy: validation policy
423 * @extack: extended ACK report struct
424 */
425static inline int nlmsg_validate(const struct nlmsghdr *nlh,
426 int hdrlen, int maxtype,
427 const struct nla_policy *policy,
428 struct netlink_ext_ack *extack)
429{
430 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
431 return -EINVAL;
432
433 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
434 nlmsg_attrlen(nlh, hdrlen), maxtype, policy,
435 extack);
436}
437
438/**
439 * nlmsg_report - need to report back to application?
440 * @nlh: netlink message header
441 *
442 * Returns 1 if a report back to the application is requested.
443 */
444static inline int nlmsg_report(const struct nlmsghdr *nlh)
445{
446 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
447}
448
449/**
450 * nlmsg_for_each_attr - iterate over a stream of attributes
451 * @pos: loop counter, set to current attribute
452 * @nlh: netlink message header
453 * @hdrlen: length of familiy specific header
454 * @rem: initialized to len, holds bytes currently remaining in stream
455 */
456#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
457 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
458 nlmsg_attrlen(nlh, hdrlen), rem)
459
460/**
461 * nlmsg_put - Add a new netlink message to an skb
462 * @skb: socket buffer to store message in
463 * @portid: netlink PORTID of requesting application
464 * @seq: sequence number of message
465 * @type: message type
466 * @payload: length of message payload
467 * @flags: message flags
468 *
469 * Returns NULL if the tailroom of the skb is insufficient to store
470 * the message header and payload.
471 */
472static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
473 int type, int payload, int flags)
474{
475 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
476 return NULL;
477
478 return __nlmsg_put(skb, portid, seq, type, payload, flags);
479}
480
481/**
482 * nlmsg_put_answer - Add a new callback based netlink message to an skb
483 * @skb: socket buffer to store message in
484 * @cb: netlink callback
485 * @type: message type
486 * @payload: length of message payload
487 * @flags: message flags
488 *
489 * Returns NULL if the tailroom of the skb is insufficient to store
490 * the message header and payload.
491 */
492static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
493 struct netlink_callback *cb,
494 int type, int payload,
495 int flags)
496{
497 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
498 type, payload, flags);
499}
500
501/**
502 * nlmsg_new - Allocate a new netlink message
503 * @payload: size of the message payload
504 * @flags: the type of memory to allocate.
505 *
506 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
507 * and a good default is needed.
508 */
509static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
510{
511 return alloc_skb(nlmsg_total_size(payload), flags);
512}
513
514/**
515 * nlmsg_end - Finalize a netlink message
516 * @skb: socket buffer the message is stored in
517 * @nlh: netlink message header
518 *
519 * Corrects the netlink message header to include the appeneded
520 * attributes. Only necessary if attributes have been added to
521 * the message.
522 */
523static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
524{
525 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
526}
527
528/**
529 * nlmsg_get_pos - return current position in netlink message
530 * @skb: socket buffer the message is stored in
531 *
532 * Returns a pointer to the current tail of the message.
533 */
534static inline void *nlmsg_get_pos(struct sk_buff *skb)
535{
536 return skb_tail_pointer(skb);
537}
538
539/**
540 * nlmsg_trim - Trim message to a mark
541 * @skb: socket buffer the message is stored in
542 * @mark: mark to trim to
543 *
544 * Trims the message to the provided mark.
545 */
546static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
547{
548 if (mark) {
549 WARN_ON((unsigned char *) mark < skb->data);
550 skb_trim(skb, (unsigned char *) mark - skb->data);
551 }
552}
553
554/**
555 * nlmsg_cancel - Cancel construction of a netlink message
556 * @skb: socket buffer the message is stored in
557 * @nlh: netlink message header
558 *
559 * Removes the complete netlink message including all
560 * attributes from the socket buffer again.
561 */
562static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
563{
564 nlmsg_trim(skb, nlh);
565}
566
567/**
568 * nlmsg_free - free a netlink message
569 * @skb: socket buffer of netlink message
570 */
571static inline void nlmsg_free(struct sk_buff *skb)
572{
573 kfree_skb(skb);
574}
575
576/**
577 * nlmsg_multicast - multicast a netlink message
578 * @sk: netlink socket to spread messages to
579 * @skb: netlink message as socket buffer
580 * @portid: own netlink portid to avoid sending to yourself
581 * @group: multicast group id
582 * @flags: allocation flags
583 */
584static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
585 u32 portid, unsigned int group, gfp_t flags)
586{
587 int err;
588
589 NETLINK_CB(skb).dst_group = group;
590
591 err = netlink_broadcast(sk, skb, portid, group, flags);
592 if (err > 0)
593 err = 0;
594
595 return err;
596}
597
598/**
599 * nlmsg_unicast - unicast a netlink message
600 * @sk: netlink socket to spread message to
601 * @skb: netlink message as socket buffer
602 * @portid: netlink portid of the destination socket
603 */
604static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
605{
606 int err;
607
608 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
609 if (err > 0)
610 err = 0;
611
612 return err;
613}
614
615/**
616 * nlmsg_for_each_msg - iterate over a stream of messages
617 * @pos: loop counter, set to current message
618 * @head: head of message stream
619 * @len: length of message stream
620 * @rem: initialized to len, holds bytes currently remaining in stream
621 */
622#define nlmsg_for_each_msg(pos, head, len, rem) \
623 for (pos = head, rem = len; \
624 nlmsg_ok(pos, rem); \
625 pos = nlmsg_next(pos, &(rem)))
626
627/**
628 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
629 * @cb: netlink callback structure that stores the sequence number
630 * @nlh: netlink message header to write the flag to
631 *
632 * This function checks if the sequence (generation) number changed during dump
633 * and if it did, advertises it in the netlink message header.
634 *
635 * The correct way to use it is to set cb->seq to the generation counter when
636 * all locks for dumping have been acquired, and then call this function for
637 * each message that is generated.
638 *
639 * Note that due to initialisation concerns, 0 is an invalid sequence number
640 * and must not be used by code that uses this functionality.
641 */
642static inline void
643nl_dump_check_consistent(struct netlink_callback *cb,
644 struct nlmsghdr *nlh)
645{
646 if (cb->prev_seq && cb->seq != cb->prev_seq)
647 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
648 cb->prev_seq = cb->seq;
649}
650
651/**************************************************************************
652 * Netlink Attributes
653 **************************************************************************/
654
655/**
656 * nla_attr_size - length of attribute not including padding
657 * @payload: length of payload
658 */
659static inline int nla_attr_size(int payload)
660{
661 return NLA_HDRLEN + payload;
662}
663
664/**
665 * nla_total_size - total length of attribute including padding
666 * @payload: length of payload
667 */
668static inline int nla_total_size(int payload)
669{
670 return NLA_ALIGN(nla_attr_size(payload));
671}
672
673/**
674 * nla_padlen - length of padding at the tail of attribute
675 * @payload: length of payload
676 */
677static inline int nla_padlen(int payload)
678{
679 return nla_total_size(payload) - nla_attr_size(payload);
680}
681
682/**
683 * nla_type - attribute type
684 * @nla: netlink attribute
685 */
686static inline int nla_type(const struct nlattr *nla)
687{
688 return nla->nla_type & NLA_TYPE_MASK;
689}
690
691/**
692 * nla_data - head of payload
693 * @nla: netlink attribute
694 */
695static inline void *nla_data(const struct nlattr *nla)
696{
697 return (char *) nla + NLA_HDRLEN;
698}
699
700/**
701 * nla_len - length of payload
702 * @nla: netlink attribute
703 */
704static inline int nla_len(const struct nlattr *nla)
705{
706 return nla->nla_len - NLA_HDRLEN;
707}
708
709/**
710 * nla_ok - check if the netlink attribute fits into the remaining bytes
711 * @nla: netlink attribute
712 * @remaining: number of bytes remaining in attribute stream
713 */
714static inline int nla_ok(const struct nlattr *nla, int remaining)
715{
716 return remaining >= (int) sizeof(*nla) &&
717 nla->nla_len >= sizeof(*nla) &&
718 nla->nla_len <= remaining;
719}
720
721/**
722 * nla_next - next netlink attribute in attribute stream
723 * @nla: netlink attribute
724 * @remaining: number of bytes remaining in attribute stream
725 *
726 * Returns the next netlink attribute in the attribute stream and
727 * decrements remaining by the size of the current attribute.
728 */
729static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
730{
731 unsigned int totlen = NLA_ALIGN(nla->nla_len);
732
733 *remaining -= totlen;
734 return (struct nlattr *) ((char *) nla + totlen);
735}
736
737/**
738 * nla_find_nested - find attribute in a set of nested attributes
739 * @nla: attribute containing the nested attributes
740 * @attrtype: type of attribute to look for
741 *
742 * Returns the first attribute which matches the specified type.
743 */
744static inline struct nlattr *
745nla_find_nested(const struct nlattr *nla, int attrtype)
746{
747 return nla_find(nla_data(nla), nla_len(nla), attrtype);
748}
749
750/**
751 * nla_parse_nested - parse nested attributes
752 * @tb: destination array with maxtype+1 elements
753 * @maxtype: maximum attribute type to be expected
754 * @nla: attribute containing the nested attributes
755 * @policy: validation policy
756 * @extack: extended ACK report struct
757 *
758 * See nla_parse()
759 */
760static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
761 const struct nlattr *nla,
762 const struct nla_policy *policy,
763 struct netlink_ext_ack *extack)
764{
765 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
766 extack);
767}
768
769/**
770 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
771 * @skb: socket buffer to add attribute to
772 * @attrtype: attribute type
773 * @value: numeric value
774 */
775static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
776{
777 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
778 u8 tmp = value;
779
780 return nla_put(skb, attrtype, sizeof(u8), &tmp);
781}
782
783/**
784 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
785 * @skb: socket buffer to add attribute to
786 * @attrtype: attribute type
787 * @value: numeric value
788 */
789static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
790{
791 u16 tmp = value;
792
793 return nla_put(skb, attrtype, sizeof(u16), &tmp);
794}
795
796/**
797 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
798 * @skb: socket buffer to add attribute to
799 * @attrtype: attribute type
800 * @value: numeric value
801 */
802static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
803{
804 __be16 tmp = value;
805
806 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
807}
808
809/**
810 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
811 * @skb: socket buffer to add attribute to
812 * @attrtype: attribute type
813 * @value: numeric value
814 */
815static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
816{
817 __be16 tmp = value;
818
819 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
820}
821
822/**
823 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
824 * @skb: socket buffer to add attribute to
825 * @attrtype: attribute type
826 * @value: numeric value
827 */
828static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
829{
830 __le16 tmp = value;
831
832 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
833}
834
835/**
836 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
837 * @skb: socket buffer to add attribute to
838 * @attrtype: attribute type
839 * @value: numeric value
840 */
841static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
842{
843 u32 tmp = value;
844
845 return nla_put(skb, attrtype, sizeof(u32), &tmp);
846}
847
848/**
849 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
850 * @skb: socket buffer to add attribute to
851 * @attrtype: attribute type
852 * @value: numeric value
853 */
854static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
855{
856 __be32 tmp = value;
857
858 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
859}
860
861/**
862 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
863 * @skb: socket buffer to add attribute to
864 * @attrtype: attribute type
865 * @value: numeric value
866 */
867static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
868{
869 __be32 tmp = value;
870
871 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
872}
873
874/**
875 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
876 * @skb: socket buffer to add attribute to
877 * @attrtype: attribute type
878 * @value: numeric value
879 */
880static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
881{
882 __le32 tmp = value;
883
884 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
885}
886
887/**
888 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
889 * @skb: socket buffer to add attribute to
890 * @attrtype: attribute type
891 * @value: numeric value
892 * @padattr: attribute type for the padding
893 */
894static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
895 u64 value, int padattr)
896{
897 u64 tmp = value;
898
899 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
900}
901
902/**
903 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
904 * @skb: socket buffer to add attribute to
905 * @attrtype: attribute type
906 * @value: numeric value
907 * @padattr: attribute type for the padding
908 */
909static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
910 int padattr)
911{
912 __be64 tmp = value;
913
914 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
915}
916
917/**
918 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
919 * @skb: socket buffer to add attribute to
920 * @attrtype: attribute type
921 * @value: numeric value
922 * @padattr: attribute type for the padding
923 */
924static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
925 int padattr)
926{
927 __be64 tmp = value;
928
929 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
930 padattr);
931}
932
933/**
934 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
935 * @skb: socket buffer to add attribute to
936 * @attrtype: attribute type
937 * @value: numeric value
938 * @padattr: attribute type for the padding
939 */
940static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
941 int padattr)
942{
943 __le64 tmp = value;
944
945 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
946}
947
948/**
949 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
950 * @skb: socket buffer to add attribute to
951 * @attrtype: attribute type
952 * @value: numeric value
953 */
954static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
955{
956 s8 tmp = value;
957
958 return nla_put(skb, attrtype, sizeof(s8), &tmp);
959}
960
961/**
962 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
963 * @skb: socket buffer to add attribute to
964 * @attrtype: attribute type
965 * @value: numeric value
966 */
967static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
968{
969 s16 tmp = value;
970
971 return nla_put(skb, attrtype, sizeof(s16), &tmp);
972}
973
974/**
975 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
976 * @skb: socket buffer to add attribute to
977 * @attrtype: attribute type
978 * @value: numeric value
979 */
980static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
981{
982 s32 tmp = value;
983
984 return nla_put(skb, attrtype, sizeof(s32), &tmp);
985}
986
987/**
988 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
989 * @skb: socket buffer to add attribute to
990 * @attrtype: attribute type
991 * @value: numeric value
992 * @padattr: attribute type for the padding
993 */
994static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
995 int padattr)
996{
997 s64 tmp = value;
998
999 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1000}
1001
1002/**
1003 * nla_put_string - Add a string netlink attribute to a socket buffer
1004 * @skb: socket buffer to add attribute to
1005 * @attrtype: attribute type
1006 * @str: NUL terminated string
1007 */
1008static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1009 const char *str)
1010{
1011 return nla_put(skb, attrtype, strlen(str) + 1, str);
1012}
1013
1014/**
1015 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1016 * @skb: socket buffer to add attribute to
1017 * @attrtype: attribute type
1018 */
1019static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1020{
1021 return nla_put(skb, attrtype, 0, NULL);
1022}
1023
1024/**
1025 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1026 * @skb: socket buffer to add attribute to
1027 * @attrtype: attribute type
1028 * @njiffies: number of jiffies to convert to msecs
1029 * @padattr: attribute type for the padding
1030 */
1031static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1032 unsigned long njiffies, int padattr)
1033{
1034 u64 tmp = jiffies_to_msecs(njiffies);
1035
1036 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1037}
1038
1039/**
1040 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1041 * buffer
1042 * @skb: socket buffer to add attribute to
1043 * @attrtype: attribute type
1044 * @addr: IPv4 address
1045 */
1046static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1047 __be32 addr)
1048{
1049 __be32 tmp = addr;
1050
1051 return nla_put_be32(skb, attrtype, tmp);
1052}
1053
1054/**
1055 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1056 * buffer
1057 * @skb: socket buffer to add attribute to
1058 * @attrtype: attribute type
1059 * @addr: IPv6 address
1060 */
1061static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1062 const struct in6_addr *addr)
1063{
1064 return nla_put(skb, attrtype, sizeof(*addr), addr);
1065}
1066
1067/**
1068 * nla_get_u32 - return payload of u32 attribute
1069 * @nla: u32 netlink attribute
1070 */
1071static inline u32 nla_get_u32(const struct nlattr *nla)
1072{
1073 return *(u32 *) nla_data(nla);
1074}
1075
1076/**
1077 * nla_get_be32 - return payload of __be32 attribute
1078 * @nla: __be32 netlink attribute
1079 */
1080static inline __be32 nla_get_be32(const struct nlattr *nla)
1081{
1082 return *(__be32 *) nla_data(nla);
1083}
1084
1085/**
1086 * nla_get_le32 - return payload of __le32 attribute
1087 * @nla: __le32 netlink attribute
1088 */
1089static inline __le32 nla_get_le32(const struct nlattr *nla)
1090{
1091 return *(__le32 *) nla_data(nla);
1092}
1093
1094/**
1095 * nla_get_u16 - return payload of u16 attribute
1096 * @nla: u16 netlink attribute
1097 */
1098static inline u16 nla_get_u16(const struct nlattr *nla)
1099{
1100 return *(u16 *) nla_data(nla);
1101}
1102
1103/**
1104 * nla_get_be16 - return payload of __be16 attribute
1105 * @nla: __be16 netlink attribute
1106 */
1107static inline __be16 nla_get_be16(const struct nlattr *nla)
1108{
1109 return *(__be16 *) nla_data(nla);
1110}
1111
1112/**
1113 * nla_get_le16 - return payload of __le16 attribute
1114 * @nla: __le16 netlink attribute
1115 */
1116static inline __le16 nla_get_le16(const struct nlattr *nla)
1117{
1118 return *(__le16 *) nla_data(nla);
1119}
1120
1121/**
1122 * nla_get_u8 - return payload of u8 attribute
1123 * @nla: u8 netlink attribute
1124 */
1125static inline u8 nla_get_u8(const struct nlattr *nla)
1126{
1127 return *(u8 *) nla_data(nla);
1128}
1129
1130/**
1131 * nla_get_u64 - return payload of u64 attribute
1132 * @nla: u64 netlink attribute
1133 */
1134static inline u64 nla_get_u64(const struct nlattr *nla)
1135{
1136 u64 tmp;
1137
1138 nla_memcpy(&tmp, nla, sizeof(tmp));
1139
1140 return tmp;
1141}
1142
1143/**
1144 * nla_get_be64 - return payload of __be64 attribute
1145 * @nla: __be64 netlink attribute
1146 */
1147static inline __be64 nla_get_be64(const struct nlattr *nla)
1148{
1149 __be64 tmp;
1150
1151 nla_memcpy(&tmp, nla, sizeof(tmp));
1152
1153 return tmp;
1154}
1155
1156/**
1157 * nla_get_le64 - return payload of __le64 attribute
1158 * @nla: __le64 netlink attribute
1159 */
1160static inline __le64 nla_get_le64(const struct nlattr *nla)
1161{
1162 return *(__le64 *) nla_data(nla);
1163}
1164
1165/**
1166 * nla_get_s32 - return payload of s32 attribute
1167 * @nla: s32 netlink attribute
1168 */
1169static inline s32 nla_get_s32(const struct nlattr *nla)
1170{
1171 return *(s32 *) nla_data(nla);
1172}
1173
1174/**
1175 * nla_get_s16 - return payload of s16 attribute
1176 * @nla: s16 netlink attribute
1177 */
1178static inline s16 nla_get_s16(const struct nlattr *nla)
1179{
1180 return *(s16 *) nla_data(nla);
1181}
1182
1183/**
1184 * nla_get_s8 - return payload of s8 attribute
1185 * @nla: s8 netlink attribute
1186 */
1187static inline s8 nla_get_s8(const struct nlattr *nla)
1188{
1189 return *(s8 *) nla_data(nla);
1190}
1191
1192/**
1193 * nla_get_s64 - return payload of s64 attribute
1194 * @nla: s64 netlink attribute
1195 */
1196static inline s64 nla_get_s64(const struct nlattr *nla)
1197{
1198 s64 tmp;
1199
1200 nla_memcpy(&tmp, nla, sizeof(tmp));
1201
1202 return tmp;
1203}
1204
1205/**
1206 * nla_get_flag - return payload of flag attribute
1207 * @nla: flag netlink attribute
1208 */
1209static inline int nla_get_flag(const struct nlattr *nla)
1210{
1211 return !!nla;
1212}
1213
1214/**
1215 * nla_get_msecs - return payload of msecs attribute
1216 * @nla: msecs netlink attribute
1217 *
1218 * Returns the number of milliseconds in jiffies.
1219 */
1220static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1221{
1222 u64 msecs = nla_get_u64(nla);
1223
1224 return msecs_to_jiffies((unsigned long) msecs);
1225}
1226
1227/**
1228 * nla_get_in_addr - return payload of IPv4 address attribute
1229 * @nla: IPv4 address netlink attribute
1230 */
1231static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1232{
1233 return *(__be32 *) nla_data(nla);
1234}
1235
1236/**
1237 * nla_get_in6_addr - return payload of IPv6 address attribute
1238 * @nla: IPv6 address netlink attribute
1239 */
1240static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1241{
1242 struct in6_addr tmp;
1243
1244 nla_memcpy(&tmp, nla, sizeof(tmp));
1245 return tmp;
1246}
1247
1248/**
1249 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1250 * @nla: nla_bitfield32 attribute
1251 */
1252static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1253{
1254 struct nla_bitfield32 tmp;
1255
1256 nla_memcpy(&tmp, nla, sizeof(tmp));
1257 return tmp;
1258}
1259
1260/**
1261 * nla_memdup - duplicate attribute memory (kmemdup)
1262 * @src: netlink attribute to duplicate from
1263 * @gfp: GFP mask
1264 */
1265static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1266{
1267 return kmemdup(nla_data(src), nla_len(src), gfp);
1268}
1269
1270/**
1271 * nla_nest_start - Start a new level of nested attributes
1272 * @skb: socket buffer to add attributes to
1273 * @attrtype: attribute type of container
1274 *
1275 * Returns the container attribute
1276 */
1277static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1278{
1279 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1280
1281 if (nla_put(skb, attrtype, 0, NULL) < 0)
1282 return NULL;
1283
1284 return start;
1285}
1286
1287/**
1288 * nla_nest_end - Finalize nesting of attributes
1289 * @skb: socket buffer the attributes are stored in
1290 * @start: container attribute
1291 *
1292 * Corrects the container attribute header to include the all
1293 * appeneded attributes.
1294 *
1295 * Returns the total data length of the skb.
1296 */
1297static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1298{
1299 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1300 return skb->len;
1301}
1302
1303/**
1304 * nla_nest_cancel - Cancel nesting of attributes
1305 * @skb: socket buffer the message is stored in
1306 * @start: container attribute
1307 *
1308 * Removes the container attribute and including all nested
1309 * attributes. Returns -EMSGSIZE
1310 */
1311static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1312{
1313 nlmsg_trim(skb, start);
1314}
1315
1316/**
1317 * nla_validate_nested - Validate a stream of nested attributes
1318 * @start: container attribute
1319 * @maxtype: maximum attribute type to be expected
1320 * @policy: validation policy
1321 * @extack: extended ACK report struct
1322 *
1323 * Validates all attributes in the nested attribute stream against the
1324 * specified policy. Attributes with a type exceeding maxtype will be
1325 * ignored. See documenation of struct nla_policy for more details.
1326 *
1327 * Returns 0 on success or a negative error code.
1328 */
1329static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
1330 const struct nla_policy *policy,
1331 struct netlink_ext_ack *extack)
1332{
1333 return nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1334 extack);
1335}
1336
1337/**
1338 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1339 * @skb: socket buffer the message is stored in
1340 *
1341 * Return true if padding is needed to align the next attribute (nla_data()) to
1342 * a 64-bit aligned area.
1343 */
1344static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1345{
1346#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1347 /* The nlattr header is 4 bytes in size, that's why we test
1348 * if the skb->data _is_ aligned. A NOP attribute, plus
1349 * nlattr header for next attribute, will make nla_data()
1350 * 8-byte aligned.
1351 */
1352 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1353 return true;
1354#endif
1355 return false;
1356}
1357
1358/**
1359 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1360 * @skb: socket buffer the message is stored in
1361 * @padattr: attribute type for the padding
1362 *
1363 * Conditionally emit a padding netlink attribute in order to make
1364 * the next attribute we emit have a 64-bit aligned nla_data() area.
1365 * This will only be done in architectures which do not have
1366 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1367 *
1368 * Returns zero on success or a negative error code.
1369 */
1370static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1371{
1372 if (nla_need_padding_for_64bit(skb) &&
1373 !nla_reserve(skb, padattr, 0))
1374 return -EMSGSIZE;
1375
1376 return 0;
1377}
1378
1379/**
1380 * nla_total_size_64bit - total length of attribute including padding
1381 * @payload: length of payload
1382 */
1383static inline int nla_total_size_64bit(int payload)
1384{
1385 return NLA_ALIGN(nla_attr_size(payload))
1386#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1387 + NLA_ALIGN(nla_attr_size(0))
1388#endif
1389 ;
1390}
1391
1392/**
1393 * nla_for_each_attr - iterate over a stream of attributes
1394 * @pos: loop counter, set to current attribute
1395 * @head: head of attribute stream
1396 * @len: length of attribute stream
1397 * @rem: initialized to len, holds bytes currently remaining in stream
1398 */
1399#define nla_for_each_attr(pos, head, len, rem) \
1400 for (pos = head, rem = len; \
1401 nla_ok(pos, rem); \
1402 pos = nla_next(pos, &(rem)))
1403
1404/**
1405 * nla_for_each_nested - iterate over nested attributes
1406 * @pos: loop counter, set to current attribute
1407 * @nla: attribute containing the nested attributes
1408 * @rem: initialized to len, holds bytes currently remaining in stream
1409 */
1410#define nla_for_each_nested(pos, nla, rem) \
1411 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1412
1413/**
1414 * nla_is_last - Test if attribute is last in stream
1415 * @nla: attribute to test
1416 * @rem: bytes remaining in stream
1417 */
1418static inline bool nla_is_last(const struct nlattr *nla, int rem)
1419{
1420 return nla->nla_len == rem;
1421}
1422
1423#endif