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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
8/* ========================================================================
9 * Netlink Messages and Attributes Interface (As Seen On TV)
10 * ------------------------------------------------------------------------
11 * Messages Interface
12 * ------------------------------------------------------------------------
13 *
14 * Message Format:
15 * <--- nlmsg_total_size(payload) --->
16 * <-- nlmsg_msg_size(payload) ->
17 * +----------+- - -+-------------+- - -+-------- - -
18 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr
19 * +----------+- - -+-------------+- - -+-------- - -
20 * nlmsg_data(nlh)---^ ^
21 * nlmsg_next(nlh)-----------------------+
22 *
23 * Payload Format:
24 * <---------------------- nlmsg_len(nlh) --------------------->
25 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
26 * +----------------------+- - -+--------------------------------+
27 * | Family Header | Pad | Attributes |
28 * +----------------------+- - -+--------------------------------+
29 * nlmsg_attrdata(nlh, hdrlen)---^
30 *
31 * Data Structures:
32 * struct nlmsghdr netlink message header
33 *
34 * Message Construction:
35 * nlmsg_new() create a new netlink message
36 * nlmsg_put() add a netlink message to an skb
37 * nlmsg_put_answer() callback based nlmsg_put()
38 * nlmsg_end() finalize netlink message
39 * nlmsg_get_pos() return current position in message
40 * nlmsg_trim() trim part of message
41 * nlmsg_cancel() cancel message construction
42 * nlmsg_free() free a netlink message
43 *
44 * Message Sending:
45 * nlmsg_multicast() multicast message to several groups
46 * nlmsg_unicast() unicast a message to a single socket
47 * nlmsg_notify() send notification message
48 *
49 * Message Length Calculations:
50 * nlmsg_msg_size(payload) length of message w/o padding
51 * nlmsg_total_size(payload) length of message w/ padding
52 * nlmsg_padlen(payload) length of padding at tail
53 *
54 * Message Payload Access:
55 * nlmsg_data(nlh) head of message payload
56 * nlmsg_len(nlh) length of message payload
57 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
58 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
59 *
60 * Message Parsing:
61 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
62 * nlmsg_next(nlh, remaining) get next netlink message
63 * nlmsg_parse() parse attributes of a message
64 * nlmsg_find_attr() find an attribute in a message
65 * nlmsg_for_each_msg() loop over all messages
66 * nlmsg_validate() validate netlink message incl. attrs
67 * nlmsg_for_each_attr() loop over all attributes
68 *
69 * Misc:
70 * nlmsg_report() report back to application?
71 *
72 * ------------------------------------------------------------------------
73 * Attributes Interface
74 * ------------------------------------------------------------------------
75 *
76 * Attribute Format:
77 * <------- nla_total_size(payload) ------->
78 * <---- nla_attr_size(payload) ----->
79 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
80 * | Header | Pad | Payload | Pad | Header
81 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
82 * <- nla_len(nla) -> ^
83 * nla_data(nla)----^ |
84 * nla_next(nla)-----------------------------'
85 *
86 * Data Structures:
87 * struct nlattr netlink attribute header
88 *
89 * Attribute Construction:
90 * nla_reserve(skb, type, len) reserve room for an attribute
91 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
92 * nla_put(skb, type, len, data) add attribute to skb
93 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
94 * nla_append(skb, len, data) append data to skb
95 *
96 * Attribute Construction for Basic Types:
97 * nla_put_u8(skb, type, value) add u8 attribute to skb
98 * nla_put_u16(skb, type, value) add u16 attribute to skb
99 * nla_put_u32(skb, type, value) add u32 attribute to skb
100 * nla_put_u64(skb, type, value) add u64 attribute to skb
101 * nla_put_string(skb, type, str) add string attribute to skb
102 * nla_put_flag(skb, type) add flag attribute to skb
103 * nla_put_msecs(skb, type, jiffies) add msecs attribute to skb
104 *
105 * Exceptions Based Attribute Construction:
106 * NLA_PUT(skb, type, len, data) add attribute to skb
107 * NLA_PUT_U8(skb, type, value) add u8 attribute to skb
108 * NLA_PUT_U16(skb, type, value) add u16 attribute to skb
109 * NLA_PUT_U32(skb, type, value) add u32 attribute to skb
110 * NLA_PUT_U64(skb, type, value) add u64 attribute to skb
111 * NLA_PUT_STRING(skb, type, str) add string attribute to skb
112 * NLA_PUT_FLAG(skb, type) add flag attribute to skb
113 * NLA_PUT_MSECS(skb, type, jiffies) add msecs attribute to skb
114 *
115 * The meaning of these functions is equal to their lower case
116 * variants but they jump to the label nla_put_failure in case
117 * of a failure.
118 *
119 * Nested Attributes Construction:
120 * nla_nest_start(skb, type) start a nested attribute
121 * nla_nest_end(skb, nla) finalize a nested attribute
122 * nla_nest_cancel(skb, nla) cancel nested attribute construction
123 *
124 * Attribute Length Calculations:
125 * nla_attr_size(payload) length of attribute w/o padding
126 * nla_total_size(payload) length of attribute w/ padding
127 * nla_padlen(payload) length of padding
128 *
129 * Attribute Payload Access:
130 * nla_data(nla) head of attribute payload
131 * nla_len(nla) length of attribute payload
132 *
133 * Attribute Payload Access for Basic Types:
134 * nla_get_u8(nla) get payload for a u8 attribute
135 * nla_get_u16(nla) get payload for a u16 attribute
136 * nla_get_u32(nla) get payload for a u32 attribute
137 * nla_get_u64(nla) get payload for a u64 attribute
138 * nla_get_flag(nla) return 1 if flag is true
139 * nla_get_msecs(nla) get payload for a msecs attribute
140 *
141 * Attribute Misc:
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
146 *
147 * Attribute Parsing:
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 *=========================================================================
159 */
160
161 /**
162 * Standard attribute types to specify validation policy
163 */
164enum {
165 NLA_UNSPEC,
166 NLA_U8,
167 NLA_U16,
168 NLA_U32,
169 NLA_U64,
170 NLA_STRING,
171 NLA_FLAG,
172 NLA_MSECS,
173 NLA_NESTED,
174 NLA_NESTED_COMPAT,
175 NLA_NUL_STRING,
176 NLA_BINARY,
177 __NLA_TYPE_MAX,
178};
179
180#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
181
182/**
183 * struct nla_policy - attribute validation policy
184 * @type: Type of attribute or NLA_UNSPEC
185 * @len: Type specific length of payload
186 *
187 * Policies are defined as arrays of this struct, the array must be
188 * accessible by attribute type up to the highest identifier to be expected.
189 *
190 * Meaning of `len' field:
191 * NLA_STRING Maximum length of string
192 * NLA_NUL_STRING Maximum length of string (excluding NUL)
193 * NLA_FLAG Unused
194 * NLA_BINARY Maximum length of attribute payload
195 * NLA_NESTED_COMPAT Exact length of structure payload
196 * All other Exact length of attribute payload
197 *
198 * Example:
199 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
200 * [ATTR_FOO] = { .type = NLA_U16 },
201 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
202 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
203 * };
204 */
205struct nla_policy {
206 u16 type;
207 u16 len;
208};
209
210/**
211 * struct nl_info - netlink source information
212 * @nlh: Netlink message header of original request
213 * @pid: Netlink PID of requesting application
214 */
215struct nl_info {
216 struct nlmsghdr *nlh;
217 struct net *nl_net;
218 u32 pid;
219};
220
221extern int netlink_rcv_skb(struct sk_buff *skb,
222 int (*cb)(struct sk_buff *,
223 struct nlmsghdr *));
224extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb,
225 u32 pid, unsigned int group, int report,
226 gfp_t flags);
227
228extern int nla_validate(const struct nlattr *head,
229 int len, int maxtype,
230 const struct nla_policy *policy);
231extern int nla_parse(struct nlattr **tb, int maxtype,
232 const struct nlattr *head, int len,
233 const struct nla_policy *policy);
234extern int nla_policy_len(const struct nla_policy *, int);
235extern struct nlattr * nla_find(const struct nlattr *head,
236 int len, int attrtype);
237extern size_t nla_strlcpy(char *dst, const struct nlattr *nla,
238 size_t dstsize);
239extern int nla_memcpy(void *dest, const struct nlattr *src, int count);
240extern int nla_memcmp(const struct nlattr *nla, const void *data,
241 size_t size);
242extern int nla_strcmp(const struct nlattr *nla, const char *str);
243extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype,
244 int attrlen);
245extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
246extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype,
247 int attrlen);
248extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
249extern void __nla_put(struct sk_buff *skb, int attrtype,
250 int attrlen, const void *data);
251extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen,
252 const void *data);
253extern int nla_put(struct sk_buff *skb, int attrtype,
254 int attrlen, const void *data);
255extern int nla_put_nohdr(struct sk_buff *skb, int attrlen,
256 const void *data);
257extern int nla_append(struct sk_buff *skb, int attrlen,
258 const void *data);
259
260/**************************************************************************
261 * Netlink Messages
262 **************************************************************************/
263
264/**
265 * nlmsg_msg_size - length of netlink message not including padding
266 * @payload: length of message payload
267 */
268static inline int nlmsg_msg_size(int payload)
269{
270 return NLMSG_HDRLEN + payload;
271}
272
273/**
274 * nlmsg_total_size - length of netlink message including padding
275 * @payload: length of message payload
276 */
277static inline int nlmsg_total_size(int payload)
278{
279 return NLMSG_ALIGN(nlmsg_msg_size(payload));
280}
281
282/**
283 * nlmsg_padlen - length of padding at the message's tail
284 * @payload: length of message payload
285 */
286static inline int nlmsg_padlen(int payload)
287{
288 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
289}
290
291/**
292 * nlmsg_data - head of message payload
293 * @nlh: netlink message header
294 */
295static inline void *nlmsg_data(const struct nlmsghdr *nlh)
296{
297 return (unsigned char *) nlh + NLMSG_HDRLEN;
298}
299
300/**
301 * nlmsg_len - length of message payload
302 * @nlh: netlink message header
303 */
304static inline int nlmsg_len(const struct nlmsghdr *nlh)
305{
306 return nlh->nlmsg_len - NLMSG_HDRLEN;
307}
308
309/**
310 * nlmsg_attrdata - head of attributes data
311 * @nlh: netlink message header
312 * @hdrlen: length of family specific header
313 */
314static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
315 int hdrlen)
316{
317 unsigned char *data = nlmsg_data(nlh);
318 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
319}
320
321/**
322 * nlmsg_attrlen - length of attributes data
323 * @nlh: netlink message header
324 * @hdrlen: length of family specific header
325 */
326static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
327{
328 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
329}
330
331/**
332 * nlmsg_ok - check if the netlink message fits into the remaining bytes
333 * @nlh: netlink message header
334 * @remaining: number of bytes remaining in message stream
335 */
336static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
337{
338 return (remaining >= (int) sizeof(struct nlmsghdr) &&
339 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
340 nlh->nlmsg_len <= remaining);
341}
342
343/**
344 * nlmsg_next - next netlink message in message stream
345 * @nlh: netlink message header
346 * @remaining: number of bytes remaining in message stream
347 *
348 * Returns the next netlink message in the message stream and
349 * decrements remaining by the size of the current message.
350 */
351static inline struct nlmsghdr *
352nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
353{
354 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
355
356 *remaining -= totlen;
357
358 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
359}
360
361/**
362 * nlmsg_parse - parse attributes of a netlink message
363 * @nlh: netlink message header
364 * @hdrlen: length of family specific header
365 * @tb: destination array with maxtype+1 elements
366 * @maxtype: maximum attribute type to be expected
367 * @policy: validation policy
368 *
369 * See nla_parse()
370 */
371static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
372 struct nlattr *tb[], int maxtype,
373 const struct nla_policy *policy)
374{
375 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
376 return -EINVAL;
377
378 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
379 nlmsg_attrlen(nlh, hdrlen), policy);
380}
381
382/**
383 * nlmsg_find_attr - find a specific attribute in a netlink message
384 * @nlh: netlink message header
385 * @hdrlen: length of familiy specific header
386 * @attrtype: type of attribute to look for
387 *
388 * Returns the first attribute which matches the specified type.
389 */
390static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
391 int hdrlen, int attrtype)
392{
393 return nla_find(nlmsg_attrdata(nlh, hdrlen),
394 nlmsg_attrlen(nlh, hdrlen), attrtype);
395}
396
397/**
398 * nlmsg_validate - validate a netlink message including attributes
399 * @nlh: netlinket message header
400 * @hdrlen: length of familiy specific header
401 * @maxtype: maximum attribute type to be expected
402 * @policy: validation policy
403 */
404static inline int nlmsg_validate(const struct nlmsghdr *nlh,
405 int hdrlen, int maxtype,
406 const struct nla_policy *policy)
407{
408 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
409 return -EINVAL;
410
411 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
412 nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
413}
414
415/**
416 * nlmsg_report - need to report back to application?
417 * @nlh: netlink message header
418 *
419 * Returns 1 if a report back to the application is requested.
420 */
421static inline int nlmsg_report(const struct nlmsghdr *nlh)
422{
423 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
424}
425
426/**
427 * nlmsg_for_each_attr - iterate over a stream of attributes
428 * @pos: loop counter, set to current attribute
429 * @nlh: netlink message header
430 * @hdrlen: length of familiy specific header
431 * @rem: initialized to len, holds bytes currently remaining in stream
432 */
433#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
434 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
435 nlmsg_attrlen(nlh, hdrlen), rem)
436
437#if 0
438/* FIXME: Enable once all users have been converted */
439
440/**
441 * __nlmsg_put - Add a new netlink message to an skb
442 * @skb: socket buffer to store message in
443 * @pid: netlink process id
444 * @seq: sequence number of message
445 * @type: message type
446 * @payload: length of message payload
447 * @flags: message flags
448 *
449 * The caller is responsible to ensure that the skb provides enough
450 * tailroom for both the netlink header and payload.
451 */
452static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid,
453 u32 seq, int type, int payload,
454 int flags)
455{
456 struct nlmsghdr *nlh;
457
458 nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload));
459 nlh->nlmsg_type = type;
460 nlh->nlmsg_len = nlmsg_msg_size(payload);
461 nlh->nlmsg_flags = flags;
462 nlh->nlmsg_pid = pid;
463 nlh->nlmsg_seq = seq;
464
465 memset((unsigned char *) nlmsg_data(nlh) + payload, 0,
466 nlmsg_padlen(payload));
467
468 return nlh;
469}
470#endif
471
472/**
473 * nlmsg_put - Add a new netlink message to an skb
474 * @skb: socket buffer to store message in
475 * @pid: netlink process id
476 * @seq: sequence number of message
477 * @type: message type
478 * @payload: length of message payload
479 * @flags: message flags
480 *
481 * Returns NULL if the tailroom of the skb is insufficient to store
482 * the message header and payload.
483 */
484static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
485 int type, int payload, int flags)
486{
487 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
488 return NULL;
489
490 return __nlmsg_put(skb, pid, seq, type, payload, flags);
491}
492
493/**
494 * nlmsg_put_answer - Add a new callback based netlink message to an skb
495 * @skb: socket buffer to store message in
496 * @cb: netlink callback
497 * @type: message type
498 * @payload: length of message payload
499 * @flags: message flags
500 *
501 * Returns NULL if the tailroom of the skb is insufficient to store
502 * the message header and payload.
503 */
504static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
505 struct netlink_callback *cb,
506 int type, int payload,
507 int flags)
508{
509 return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
510 type, payload, flags);
511}
512
513/**
514 * nlmsg_new - Allocate a new netlink message
515 * @payload: size of the message payload
516 * @flags: the type of memory to allocate.
517 *
518 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
519 * and a good default is needed.
520 */
521static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
522{
523 return alloc_skb(nlmsg_total_size(payload), flags);
524}
525
526/**
527 * nlmsg_end - Finalize a netlink message
528 * @skb: socket buffer the message is stored in
529 * @nlh: netlink message header
530 *
531 * Corrects the netlink message header to include the appeneded
532 * attributes. Only necessary if attributes have been added to
533 * the message.
534 *
535 * Returns the total data length of the skb.
536 */
537static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
538{
539 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
540
541 return skb->len;
542}
543
544/**
545 * nlmsg_get_pos - return current position in netlink message
546 * @skb: socket buffer the message is stored in
547 *
548 * Returns a pointer to the current tail of the message.
549 */
550static inline void *nlmsg_get_pos(struct sk_buff *skb)
551{
552 return skb_tail_pointer(skb);
553}
554
555/**
556 * nlmsg_trim - Trim message to a mark
557 * @skb: socket buffer the message is stored in
558 * @mark: mark to trim to
559 *
560 * Trims the message to the provided mark.
561 */
562static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
563{
564 if (mark)
565 skb_trim(skb, (unsigned char *) mark - skb->data);
566}
567
568/**
569 * nlmsg_cancel - Cancel construction of a netlink message
570 * @skb: socket buffer the message is stored in
571 * @nlh: netlink message header
572 *
573 * Removes the complete netlink message including all
574 * attributes from the socket buffer again.
575 */
576static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
577{
578 nlmsg_trim(skb, nlh);
579}
580
581/**
582 * nlmsg_free - free a netlink message
583 * @skb: socket buffer of netlink message
584 */
585static inline void nlmsg_free(struct sk_buff *skb)
586{
587 kfree_skb(skb);
588}
589
590/**
591 * nlmsg_multicast - multicast a netlink message
592 * @sk: netlink socket to spread messages to
593 * @skb: netlink message as socket buffer
594 * @pid: own netlink pid to avoid sending to yourself
595 * @group: multicast group id
596 * @flags: allocation flags
597 */
598static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
599 u32 pid, unsigned int group, gfp_t flags)
600{
601 int err;
602
603 NETLINK_CB(skb).dst_group = group;
604
605 err = netlink_broadcast(sk, skb, pid, group, flags);
606 if (err > 0)
607 err = 0;
608
609 return err;
610}
611
612/**
613 * nlmsg_unicast - unicast a netlink message
614 * @sk: netlink socket to spread message to
615 * @skb: netlink message as socket buffer
616 * @pid: netlink pid of the destination socket
617 */
618static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid)
619{
620 int err;
621
622 err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT);
623 if (err > 0)
624 err = 0;
625
626 return err;
627}
628
629/**
630 * nlmsg_for_each_msg - iterate over a stream of messages
631 * @pos: loop counter, set to current message
632 * @head: head of message stream
633 * @len: length of message stream
634 * @rem: initialized to len, holds bytes currently remaining in stream
635 */
636#define nlmsg_for_each_msg(pos, head, len, rem) \
637 for (pos = head, rem = len; \
638 nlmsg_ok(pos, rem); \
639 pos = nlmsg_next(pos, &(rem)))
640
641/**
642 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
643 * @cb: netlink callback structure that stores the sequence number
644 * @nlh: netlink message header to write the flag to
645 *
646 * This function checks if the sequence (generation) number changed during dump
647 * and if it did, advertises it in the netlink message header.
648 *
649 * The correct way to use it is to set cb->seq to the generation counter when
650 * all locks for dumping have been acquired, and then call this function for
651 * each message that is generated.
652 *
653 * Note that due to initialisation concerns, 0 is an invalid sequence number
654 * and must not be used by code that uses this functionality.
655 */
656static inline void
657nl_dump_check_consistent(struct netlink_callback *cb,
658 struct nlmsghdr *nlh)
659{
660 if (cb->prev_seq && cb->seq != cb->prev_seq)
661 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
662 cb->prev_seq = cb->seq;
663}
664
665/**************************************************************************
666 * Netlink Attributes
667 **************************************************************************/
668
669/**
670 * nla_attr_size - length of attribute not including padding
671 * @payload: length of payload
672 */
673static inline int nla_attr_size(int payload)
674{
675 return NLA_HDRLEN + payload;
676}
677
678/**
679 * nla_total_size - total length of attribute including padding
680 * @payload: length of payload
681 */
682static inline int nla_total_size(int payload)
683{
684 return NLA_ALIGN(nla_attr_size(payload));
685}
686
687/**
688 * nla_padlen - length of padding at the tail of attribute
689 * @payload: length of payload
690 */
691static inline int nla_padlen(int payload)
692{
693 return nla_total_size(payload) - nla_attr_size(payload);
694}
695
696/**
697 * nla_type - attribute type
698 * @nla: netlink attribute
699 */
700static inline int nla_type(const struct nlattr *nla)
701{
702 return nla->nla_type & NLA_TYPE_MASK;
703}
704
705/**
706 * nla_data - head of payload
707 * @nla: netlink attribute
708 */
709static inline void *nla_data(const struct nlattr *nla)
710{
711 return (char *) nla + NLA_HDRLEN;
712}
713
714/**
715 * nla_len - length of payload
716 * @nla: netlink attribute
717 */
718static inline int nla_len(const struct nlattr *nla)
719{
720 return nla->nla_len - NLA_HDRLEN;
721}
722
723/**
724 * nla_ok - check if the netlink attribute fits into the remaining bytes
725 * @nla: netlink attribute
726 * @remaining: number of bytes remaining in attribute stream
727 */
728static inline int nla_ok(const struct nlattr *nla, int remaining)
729{
730 return remaining >= (int) sizeof(*nla) &&
731 nla->nla_len >= sizeof(*nla) &&
732 nla->nla_len <= remaining;
733}
734
735/**
736 * nla_next - next netlink attribute in attribute stream
737 * @nla: netlink attribute
738 * @remaining: number of bytes remaining in attribute stream
739 *
740 * Returns the next netlink attribute in the attribute stream and
741 * decrements remaining by the size of the current attribute.
742 */
743static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
744{
745 int totlen = NLA_ALIGN(nla->nla_len);
746
747 *remaining -= totlen;
748 return (struct nlattr *) ((char *) nla + totlen);
749}
750
751/**
752 * nla_find_nested - find attribute in a set of nested attributes
753 * @nla: attribute containing the nested attributes
754 * @attrtype: type of attribute to look for
755 *
756 * Returns the first attribute which matches the specified type.
757 */
758static inline struct nlattr *
759nla_find_nested(const struct nlattr *nla, int attrtype)
760{
761 return nla_find(nla_data(nla), nla_len(nla), attrtype);
762}
763
764/**
765 * nla_parse_nested - parse nested attributes
766 * @tb: destination array with maxtype+1 elements
767 * @maxtype: maximum attribute type to be expected
768 * @nla: attribute containing the nested attributes
769 * @policy: validation policy
770 *
771 * See nla_parse()
772 */
773static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
774 const struct nlattr *nla,
775 const struct nla_policy *policy)
776{
777 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
778}
779
780/**
781 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
782 * @skb: socket buffer to add attribute to
783 * @attrtype: attribute type
784 * @value: numeric value
785 */
786static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
787{
788 return nla_put(skb, attrtype, sizeof(u8), &value);
789}
790
791/**
792 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
793 * @skb: socket buffer to add attribute to
794 * @attrtype: attribute type
795 * @value: numeric value
796 */
797static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
798{
799 return nla_put(skb, attrtype, sizeof(u16), &value);
800}
801
802/**
803 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
804 * @skb: socket buffer to add attribute to
805 * @attrtype: attribute type
806 * @value: numeric value
807 */
808static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
809{
810 return nla_put(skb, attrtype, sizeof(u32), &value);
811}
812
813/**
814 * nla_put_64 - Add a u64 netlink attribute to a socket buffer
815 * @skb: socket buffer to add attribute to
816 * @attrtype: attribute type
817 * @value: numeric value
818 */
819static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
820{
821 return nla_put(skb, attrtype, sizeof(u64), &value);
822}
823
824/**
825 * nla_put_string - Add a string netlink attribute to a socket buffer
826 * @skb: socket buffer to add attribute to
827 * @attrtype: attribute type
828 * @str: NUL terminated string
829 */
830static inline int nla_put_string(struct sk_buff *skb, int attrtype,
831 const char *str)
832{
833 return nla_put(skb, attrtype, strlen(str) + 1, str);
834}
835
836/**
837 * nla_put_flag - Add a flag netlink attribute to a socket buffer
838 * @skb: socket buffer to add attribute to
839 * @attrtype: attribute type
840 */
841static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
842{
843 return nla_put(skb, attrtype, 0, NULL);
844}
845
846/**
847 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer
848 * @skb: socket buffer to add attribute to
849 * @attrtype: attribute type
850 * @jiffies: number of msecs in jiffies
851 */
852static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
853 unsigned long jiffies)
854{
855 u64 tmp = jiffies_to_msecs(jiffies);
856 return nla_put(skb, attrtype, sizeof(u64), &tmp);
857}
858
859#define NLA_PUT(skb, attrtype, attrlen, data) \
860 do { \
861 if (unlikely(nla_put(skb, attrtype, attrlen, data) < 0)) \
862 goto nla_put_failure; \
863 } while(0)
864
865#define NLA_PUT_TYPE(skb, type, attrtype, value) \
866 do { \
867 type __tmp = value; \
868 NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \
869 } while(0)
870
871#define NLA_PUT_U8(skb, attrtype, value) \
872 NLA_PUT_TYPE(skb, u8, attrtype, value)
873
874#define NLA_PUT_U16(skb, attrtype, value) \
875 NLA_PUT_TYPE(skb, u16, attrtype, value)
876
877#define NLA_PUT_LE16(skb, attrtype, value) \
878 NLA_PUT_TYPE(skb, __le16, attrtype, value)
879
880#define NLA_PUT_BE16(skb, attrtype, value) \
881 NLA_PUT_TYPE(skb, __be16, attrtype, value)
882
883#define NLA_PUT_NET16(skb, attrtype, value) \
884 NLA_PUT_BE16(skb, attrtype | NLA_F_NET_BYTEORDER, value)
885
886#define NLA_PUT_U32(skb, attrtype, value) \
887 NLA_PUT_TYPE(skb, u32, attrtype, value)
888
889#define NLA_PUT_BE32(skb, attrtype, value) \
890 NLA_PUT_TYPE(skb, __be32, attrtype, value)
891
892#define NLA_PUT_NET32(skb, attrtype, value) \
893 NLA_PUT_BE32(skb, attrtype | NLA_F_NET_BYTEORDER, value)
894
895#define NLA_PUT_U64(skb, attrtype, value) \
896 NLA_PUT_TYPE(skb, u64, attrtype, value)
897
898#define NLA_PUT_BE64(skb, attrtype, value) \
899 NLA_PUT_TYPE(skb, __be64, attrtype, value)
900
901#define NLA_PUT_NET64(skb, attrtype, value) \
902 NLA_PUT_BE64(skb, attrtype | NLA_F_NET_BYTEORDER, value)
903
904#define NLA_PUT_STRING(skb, attrtype, value) \
905 NLA_PUT(skb, attrtype, strlen(value) + 1, value)
906
907#define NLA_PUT_FLAG(skb, attrtype) \
908 NLA_PUT(skb, attrtype, 0, NULL)
909
910#define NLA_PUT_MSECS(skb, attrtype, jiffies) \
911 NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies))
912
913/**
914 * nla_get_u32 - return payload of u32 attribute
915 * @nla: u32 netlink attribute
916 */
917static inline u32 nla_get_u32(const struct nlattr *nla)
918{
919 return *(u32 *) nla_data(nla);
920}
921
922/**
923 * nla_get_be32 - return payload of __be32 attribute
924 * @nla: __be32 netlink attribute
925 */
926static inline __be32 nla_get_be32(const struct nlattr *nla)
927{
928 return *(__be32 *) nla_data(nla);
929}
930
931/**
932 * nla_get_u16 - return payload of u16 attribute
933 * @nla: u16 netlink attribute
934 */
935static inline u16 nla_get_u16(const struct nlattr *nla)
936{
937 return *(u16 *) nla_data(nla);
938}
939
940/**
941 * nla_get_be16 - return payload of __be16 attribute
942 * @nla: __be16 netlink attribute
943 */
944static inline __be16 nla_get_be16(const struct nlattr *nla)
945{
946 return *(__be16 *) nla_data(nla);
947}
948
949/**
950 * nla_get_le16 - return payload of __le16 attribute
951 * @nla: __le16 netlink attribute
952 */
953static inline __le16 nla_get_le16(const struct nlattr *nla)
954{
955 return *(__le16 *) nla_data(nla);
956}
957
958/**
959 * nla_get_u8 - return payload of u8 attribute
960 * @nla: u8 netlink attribute
961 */
962static inline u8 nla_get_u8(const struct nlattr *nla)
963{
964 return *(u8 *) nla_data(nla);
965}
966
967/**
968 * nla_get_u64 - return payload of u64 attribute
969 * @nla: u64 netlink attribute
970 */
971static inline u64 nla_get_u64(const struct nlattr *nla)
972{
973 u64 tmp;
974
975 nla_memcpy(&tmp, nla, sizeof(tmp));
976
977 return tmp;
978}
979
980/**
981 * nla_get_be64 - return payload of __be64 attribute
982 * @nla: __be64 netlink attribute
983 */
984static inline __be64 nla_get_be64(const struct nlattr *nla)
985{
986 __be64 tmp;
987
988 nla_memcpy(&tmp, nla, sizeof(tmp));
989
990 return tmp;
991}
992
993/**
994 * nla_get_flag - return payload of flag attribute
995 * @nla: flag netlink attribute
996 */
997static inline int nla_get_flag(const struct nlattr *nla)
998{
999 return !!nla;
1000}
1001
1002/**
1003 * nla_get_msecs - return payload of msecs attribute
1004 * @nla: msecs netlink attribute
1005 *
1006 * Returns the number of milliseconds in jiffies.
1007 */
1008static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1009{
1010 u64 msecs = nla_get_u64(nla);
1011
1012 return msecs_to_jiffies((unsigned long) msecs);
1013}
1014
1015/**
1016 * nla_nest_start - Start a new level of nested attributes
1017 * @skb: socket buffer to add attributes to
1018 * @attrtype: attribute type of container
1019 *
1020 * Returns the container attribute
1021 */
1022static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1023{
1024 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1025
1026 if (nla_put(skb, attrtype, 0, NULL) < 0)
1027 return NULL;
1028
1029 return start;
1030}
1031
1032/**
1033 * nla_nest_end - Finalize nesting of attributes
1034 * @skb: socket buffer the attributes are stored in
1035 * @start: container attribute
1036 *
1037 * Corrects the container attribute header to include the all
1038 * appeneded attributes.
1039 *
1040 * Returns the total data length of the skb.
1041 */
1042static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1043{
1044 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1045 return skb->len;
1046}
1047
1048/**
1049 * nla_nest_cancel - Cancel nesting of attributes
1050 * @skb: socket buffer the message is stored in
1051 * @start: container attribute
1052 *
1053 * Removes the container attribute and including all nested
1054 * attributes. Returns -EMSGSIZE
1055 */
1056static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1057{
1058 nlmsg_trim(skb, start);
1059}
1060
1061/**
1062 * nla_validate_nested - Validate a stream of nested attributes
1063 * @start: container attribute
1064 * @maxtype: maximum attribute type to be expected
1065 * @policy: validation policy
1066 *
1067 * Validates all attributes in the nested attribute stream against the
1068 * specified policy. Attributes with a type exceeding maxtype will be
1069 * ignored. See documenation of struct nla_policy for more details.
1070 *
1071 * Returns 0 on success or a negative error code.
1072 */
1073static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
1074 const struct nla_policy *policy)
1075{
1076 return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
1077}
1078
1079/**
1080 * nla_for_each_attr - iterate over a stream of attributes
1081 * @pos: loop counter, set to current attribute
1082 * @head: head of attribute stream
1083 * @len: length of attribute stream
1084 * @rem: initialized to len, holds bytes currently remaining in stream
1085 */
1086#define nla_for_each_attr(pos, head, len, rem) \
1087 for (pos = head, rem = len; \
1088 nla_ok(pos, rem); \
1089 pos = nla_next(pos, &(rem)))
1090
1091/**
1092 * nla_for_each_nested - iterate over nested attributes
1093 * @pos: loop counter, set to current attribute
1094 * @nla: attribute containing the nested attributes
1095 * @rem: initialized to len, holds bytes currently remaining in stream
1096 */
1097#define nla_for_each_nested(pos, nla, rem) \
1098 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1099
1100#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_consume() free a netlink message (expected)
45 * nlmsg_free() free a netlink message (drop)
46 *
47 * Message Sending:
48 * nlmsg_multicast() multicast message to several groups
49 * nlmsg_unicast() unicast a message to a single socket
50 * nlmsg_notify() send notification message
51 *
52 * Message Length Calculations:
53 * nlmsg_msg_size(payload) length of message w/o padding
54 * nlmsg_total_size(payload) length of message w/ padding
55 * nlmsg_padlen(payload) length of padding at tail
56 *
57 * Message Payload Access:
58 * nlmsg_data(nlh) head of message payload
59 * nlmsg_len(nlh) length of message payload
60 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
61 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
62 *
63 * Message Parsing:
64 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
65 * nlmsg_next(nlh, remaining) get next netlink message
66 * nlmsg_parse() parse attributes of a message
67 * nlmsg_find_attr() find an attribute in a message
68 * nlmsg_for_each_msg() loop over all messages
69 * nlmsg_validate() validate netlink message incl. attrs
70 * nlmsg_for_each_attr() loop over all attributes
71 *
72 * Misc:
73 * nlmsg_report() report back to application?
74 *
75 * ------------------------------------------------------------------------
76 * Attributes Interface
77 * ------------------------------------------------------------------------
78 *
79 * Attribute Format:
80 * <------- nla_total_size(payload) ------->
81 * <---- nla_attr_size(payload) ----->
82 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
83 * | Header | Pad | Payload | Pad | Header
84 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
85 * <- nla_len(nla) -> ^
86 * nla_data(nla)----^ |
87 * nla_next(nla)-----------------------------'
88 *
89 * Data Structures:
90 * struct nlattr netlink attribute header
91 *
92 * Attribute Construction:
93 * nla_reserve(skb, type, len) reserve room for an attribute
94 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
95 * nla_put(skb, type, len, data) add attribute to skb
96 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
97 * nla_append(skb, len, data) append data to skb
98 *
99 * Attribute Construction for Basic Types:
100 * nla_put_u8(skb, type, value) add u8 attribute to skb
101 * nla_put_u16(skb, type, value) add u16 attribute to skb
102 * nla_put_u32(skb, type, value) add u32 attribute to skb
103 * nla_put_u64_64bit(skb, type,
104 * value, padattr) add u64 attribute to skb
105 * nla_put_s8(skb, type, value) add s8 attribute to skb
106 * nla_put_s16(skb, type, value) add s16 attribute to skb
107 * nla_put_s32(skb, type, value) add s32 attribute to skb
108 * nla_put_s64(skb, type, value,
109 * padattr) add s64 attribute to skb
110 * nla_put_string(skb, type, str) add string attribute to skb
111 * nla_put_flag(skb, type) add flag attribute to skb
112 * nla_put_msecs(skb, type, jiffies,
113 * padattr) add msecs attribute to skb
114 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb
115 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb
116 *
117 * Nested Attributes Construction:
118 * nla_nest_start(skb, type) start a nested attribute
119 * nla_nest_end(skb, nla) finalize a nested attribute
120 * nla_nest_cancel(skb, nla) cancel nested attribute construction
121 *
122 * Attribute Length Calculations:
123 * nla_attr_size(payload) length of attribute w/o padding
124 * nla_total_size(payload) length of attribute w/ padding
125 * nla_padlen(payload) length of padding
126 *
127 * Attribute Payload Access:
128 * nla_data(nla) head of attribute payload
129 * nla_len(nla) length of attribute payload
130 *
131 * Attribute Payload Access for Basic Types:
132 * nla_get_uint(nla) get payload for a uint attribute
133 * nla_get_sint(nla) get payload for a sint attribute
134 * nla_get_u8(nla) get payload for a u8 attribute
135 * nla_get_u16(nla) get payload for a u16 attribute
136 * nla_get_u32(nla) get payload for a u32 attribute
137 * nla_get_u64(nla) get payload for a u64 attribute
138 * nla_get_s8(nla) get payload for a s8 attribute
139 * nla_get_s16(nla) get payload for a s16 attribute
140 * nla_get_s32(nla) get payload for a s32 attribute
141 * nla_get_s64(nla) get payload for a s64 attribute
142 * nla_get_flag(nla) return 1 if flag is true
143 * nla_get_msecs(nla) get payload for a msecs attribute
144 *
145 * The same functions also exist with _default().
146 *
147 * Attribute Misc:
148 * nla_memcpy(dest, nla, count) copy attribute into memory
149 * nla_memcmp(nla, data, size) compare attribute with memory area
150 * nla_strscpy(dst, nla, size) copy attribute to a sized string
151 * nla_strcmp(nla, str) compare attribute with string
152 *
153 * Attribute Parsing:
154 * nla_ok(nla, remaining) does nla fit into remaining bytes?
155 * nla_next(nla, remaining) get next netlink attribute
156 * nla_validate() validate a stream of attributes
157 * nla_validate_nested() validate a stream of nested attributes
158 * nla_find() find attribute in stream of attributes
159 * nla_find_nested() find attribute in nested attributes
160 * nla_parse() parse and validate stream of attrs
161 * nla_parse_nested() parse nested attributes
162 * nla_for_each_attr() loop over all attributes
163 * nla_for_each_attr_type() loop over all attributes with the
164 * given type
165 * nla_for_each_nested() loop over the nested attributes
166 * nla_for_each_nested_type() loop over the nested attributes with
167 * the given type
168 *=========================================================================
169 */
170
171 /**
172 * Standard attribute types to specify validation policy
173 */
174enum {
175 NLA_UNSPEC,
176 NLA_U8,
177 NLA_U16,
178 NLA_U32,
179 NLA_U64,
180 NLA_STRING,
181 NLA_FLAG,
182 NLA_MSECS,
183 NLA_NESTED,
184 NLA_NESTED_ARRAY,
185 NLA_NUL_STRING,
186 NLA_BINARY,
187 NLA_S8,
188 NLA_S16,
189 NLA_S32,
190 NLA_S64,
191 NLA_BITFIELD32,
192 NLA_REJECT,
193 NLA_BE16,
194 NLA_BE32,
195 NLA_SINT,
196 NLA_UINT,
197 __NLA_TYPE_MAX,
198};
199
200#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
201
202struct netlink_range_validation {
203 u64 min, max;
204};
205
206struct netlink_range_validation_signed {
207 s64 min, max;
208};
209
210enum nla_policy_validation {
211 NLA_VALIDATE_NONE,
212 NLA_VALIDATE_RANGE,
213 NLA_VALIDATE_RANGE_WARN_TOO_LONG,
214 NLA_VALIDATE_MIN,
215 NLA_VALIDATE_MAX,
216 NLA_VALIDATE_MASK,
217 NLA_VALIDATE_RANGE_PTR,
218 NLA_VALIDATE_FUNCTION,
219};
220
221/**
222 * struct nla_policy - attribute validation policy
223 * @type: Type of attribute or NLA_UNSPEC
224 * @validation_type: type of attribute validation done in addition to
225 * type-specific validation (e.g. range, function call), see
226 * &enum nla_policy_validation
227 * @len: Type specific length of payload
228 *
229 * Policies are defined as arrays of this struct, the array must be
230 * accessible by attribute type up to the highest identifier to be expected.
231 *
232 * Meaning of `len' field:
233 * NLA_STRING Maximum length of string
234 * NLA_NUL_STRING Maximum length of string (excluding NUL)
235 * NLA_FLAG Unused
236 * NLA_BINARY Maximum length of attribute payload
237 * (but see also below with the validation type)
238 * NLA_NESTED,
239 * NLA_NESTED_ARRAY Length verification is done by checking len of
240 * nested header (or empty); len field is used if
241 * nested_policy is also used, for the max attr
242 * number in the nested policy.
243 * NLA_SINT, NLA_UINT,
244 * NLA_U8, NLA_U16,
245 * NLA_U32, NLA_U64,
246 * NLA_S8, NLA_S16,
247 * NLA_S32, NLA_S64,
248 * NLA_BE16, NLA_BE32,
249 * NLA_MSECS Leaving the length field zero will verify the
250 * given type fits, using it verifies minimum length
251 * just like "All other"
252 * NLA_BITFIELD32 Unused
253 * NLA_REJECT Unused
254 * All other Minimum length of attribute payload
255 *
256 * Meaning of validation union:
257 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and
258 * `bitfield32_valid' is the u32 value of valid flags
259 * NLA_REJECT This attribute is always rejected and `reject_message'
260 * may point to a string to report as the error instead
261 * of the generic one in extended ACK.
262 * NLA_NESTED `nested_policy' to a nested policy to validate, must
263 * also set `len' to the max attribute number. Use the
264 * provided NLA_POLICY_NESTED() macro.
265 * Note that nla_parse() will validate, but of course not
266 * parse, the nested sub-policies.
267 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate,
268 * must also set `len' to the max attribute number. Use
269 * the provided NLA_POLICY_NESTED_ARRAY() macro.
270 * The difference to NLA_NESTED is the structure:
271 * NLA_NESTED has the nested attributes directly inside
272 * while an array has the nested attributes at another
273 * level down and the attribute types directly in the
274 * nesting don't matter.
275 * NLA_UINT,
276 * NLA_U8,
277 * NLA_U16,
278 * NLA_U32,
279 * NLA_U64,
280 * NLA_BE16,
281 * NLA_BE32,
282 * NLA_SINT,
283 * NLA_S8,
284 * NLA_S16,
285 * NLA_S32,
286 * NLA_S64 The `min' and `max' fields are used depending on the
287 * validation_type field, if that is min/max/range then
288 * the min, max or both are used (respectively) to check
289 * the value of the integer attribute.
290 * Note that in the interest of code simplicity and
291 * struct size both limits are s16, so you cannot
292 * enforce a range that doesn't fall within the range
293 * of s16 - do that using the NLA_POLICY_FULL_RANGE()
294 * or NLA_POLICY_FULL_RANGE_SIGNED() macros instead.
295 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
296 * NLA_POLICY_RANGE() macros.
297 * NLA_UINT,
298 * NLA_U8,
299 * NLA_U16,
300 * NLA_U32,
301 * NLA_U64 If the validation_type field instead is set to
302 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
303 * to a struct netlink_range_validation that indicates
304 * the min/max values.
305 * Use NLA_POLICY_FULL_RANGE().
306 * NLA_SINT,
307 * NLA_S8,
308 * NLA_S16,
309 * NLA_S32,
310 * NLA_S64 If the validation_type field instead is set to
311 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
312 * pointer to a struct netlink_range_validation_signed
313 * that indicates the min/max values.
314 * Use NLA_POLICY_FULL_RANGE_SIGNED().
315 *
316 * NLA_BINARY If the validation type is like the ones for integers
317 * above, then the min/max length (not value like for
318 * integers) of the attribute is enforced.
319 *
320 * All other Unused - but note that it's a union
321 *
322 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
323 * NLA_BINARY Validation function called for the attribute.
324 * All other Unused - but note that it's a union
325 *
326 * Example:
327 *
328 * static const u32 myvalidflags = 0xff231023;
329 *
330 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
331 * [ATTR_FOO] = { .type = NLA_U16 },
332 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
333 * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)),
334 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
335 * };
336 */
337struct nla_policy {
338 u8 type;
339 u8 validation_type;
340 u16 len;
341 union {
342 /**
343 * @strict_start_type: first attribute to validate strictly
344 *
345 * This entry is special, and used for the attribute at index 0
346 * only, and specifies special data about the policy, namely it
347 * specifies the "boundary type" where strict length validation
348 * starts for any attribute types >= this value, also, strict
349 * nesting validation starts here.
350 *
351 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
352 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to
353 * get the previous pure { .len = xyz } behaviour. The advantage
354 * of this is that types not specified in the policy will be
355 * rejected.
356 *
357 * For completely new families it should be set to 1 so that the
358 * validation is enforced for all attributes. For existing ones
359 * it should be set at least when new attributes are added to
360 * the enum used by the policy, and be set to the new value that
361 * was added to enforce strict validation from thereon.
362 */
363 u16 strict_start_type;
364
365 /* private: use NLA_POLICY_*() to set */
366 const u32 bitfield32_valid;
367 const u32 mask;
368 const char *reject_message;
369 const struct nla_policy *nested_policy;
370 const struct netlink_range_validation *range;
371 const struct netlink_range_validation_signed *range_signed;
372 struct {
373 s16 min, max;
374 };
375 int (*validate)(const struct nlattr *attr,
376 struct netlink_ext_ack *extack);
377 };
378};
379
380#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN)
381#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
382
383#define _NLA_POLICY_NESTED(maxattr, policy) \
384 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
385#define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
386 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
387#define NLA_POLICY_NESTED(policy) \
388 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
389#define NLA_POLICY_NESTED_ARRAY(policy) \
390 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
391#define NLA_POLICY_BITFIELD32(valid) \
392 { .type = NLA_BITFIELD32, .bitfield32_valid = valid }
393
394#define __NLA_IS_UINT_TYPE(tp) \
395 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || \
396 tp == NLA_U64 || tp == NLA_UINT || \
397 tp == NLA_BE16 || tp == NLA_BE32)
398#define __NLA_IS_SINT_TYPE(tp) \
399 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64 || \
400 tp == NLA_SINT)
401
402#define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
403#define NLA_ENSURE_UINT_TYPE(tp) \
404 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
405#define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \
406 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
407 tp == NLA_MSECS || \
408 tp == NLA_BINARY) + tp)
409#define NLA_ENSURE_SINT_TYPE(tp) \
410 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
411#define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \
412 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
413 __NLA_IS_SINT_TYPE(tp) || \
414 tp == NLA_MSECS || \
415 tp == NLA_BINARY) + tp)
416#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
417 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \
418 tp != NLA_REJECT && \
419 tp != NLA_NESTED && \
420 tp != NLA_NESTED_ARRAY) + tp)
421
422#define NLA_POLICY_RANGE(tp, _min, _max) { \
423 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
424 .validation_type = NLA_VALIDATE_RANGE, \
425 .min = _min, \
426 .max = _max \
427}
428
429#define NLA_POLICY_FULL_RANGE(tp, _range) { \
430 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \
431 .validation_type = NLA_VALIDATE_RANGE_PTR, \
432 .range = _range, \
433}
434
435#define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \
436 .type = NLA_ENSURE_SINT_TYPE(tp), \
437 .validation_type = NLA_VALIDATE_RANGE_PTR, \
438 .range_signed = _range, \
439}
440
441#define NLA_POLICY_MIN(tp, _min) { \
442 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
443 .validation_type = NLA_VALIDATE_MIN, \
444 .min = _min, \
445}
446
447#define NLA_POLICY_MAX(tp, _max) { \
448 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
449 .validation_type = NLA_VALIDATE_MAX, \
450 .max = _max, \
451}
452
453#define NLA_POLICY_MASK(tp, _mask) { \
454 .type = NLA_ENSURE_UINT_TYPE(tp), \
455 .validation_type = NLA_VALIDATE_MASK, \
456 .mask = _mask, \
457}
458
459#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \
460 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \
461 .validation_type = NLA_VALIDATE_FUNCTION, \
462 .validate = fn, \
463 .len = __VA_ARGS__ + 0, \
464}
465
466#define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
467#define NLA_POLICY_EXACT_LEN_WARN(_len) { \
468 .type = NLA_BINARY, \
469 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \
470 .min = _len, \
471 .max = _len \
472}
473#define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len)
474#define NLA_POLICY_MAX_LEN(_len) NLA_POLICY_MAX(NLA_BINARY, _len)
475
476/**
477 * struct nl_info - netlink source information
478 * @nlh: Netlink message header of original request
479 * @nl_net: Network namespace
480 * @portid: Netlink PORTID of requesting application
481 * @skip_notify: Skip netlink notifications to user space
482 * @skip_notify_kernel: Skip selected in-kernel notifications
483 */
484struct nl_info {
485 struct nlmsghdr *nlh;
486 struct net *nl_net;
487 u32 portid;
488 u8 skip_notify:1,
489 skip_notify_kernel:1;
490};
491
492/**
493 * enum netlink_validation - netlink message/attribute validation levels
494 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
495 * extra data at the end of the message, attributes being longer than
496 * they should be, or unknown attributes being present.
497 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
498 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
499 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
500 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
501 * This can safely be set by the kernel when the given policy has no
502 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
503 * are enforced going forward.
504 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
505 * U8, U16, U32 must have exact size, etc.)
506 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
507 * and unset for other policies.
508 */
509enum netlink_validation {
510 NL_VALIDATE_LIBERAL = 0,
511 NL_VALIDATE_TRAILING = BIT(0),
512 NL_VALIDATE_MAXTYPE = BIT(1),
513 NL_VALIDATE_UNSPEC = BIT(2),
514 NL_VALIDATE_STRICT_ATTRS = BIT(3),
515 NL_VALIDATE_NESTED = BIT(4),
516};
517
518#define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
519 NL_VALIDATE_MAXTYPE)
520#define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
521 NL_VALIDATE_MAXTYPE |\
522 NL_VALIDATE_UNSPEC |\
523 NL_VALIDATE_STRICT_ATTRS |\
524 NL_VALIDATE_NESTED)
525
526int netlink_rcv_skb(struct sk_buff *skb,
527 int (*cb)(struct sk_buff *, struct nlmsghdr *,
528 struct netlink_ext_ack *));
529int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
530 unsigned int group, int report, gfp_t flags);
531
532int __nla_validate(const struct nlattr *head, int len, int maxtype,
533 const struct nla_policy *policy, unsigned int validate,
534 struct netlink_ext_ack *extack);
535int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
536 int len, const struct nla_policy *policy, unsigned int validate,
537 struct netlink_ext_ack *extack);
538int nla_policy_len(const struct nla_policy *, int);
539struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
540ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
541char *nla_strdup(const struct nlattr *nla, gfp_t flags);
542int nla_memcpy(void *dest, const struct nlattr *src, int count);
543int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
544int nla_strcmp(const struct nlattr *nla, const char *str);
545struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
546struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
547 int attrlen, int padattr);
548void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
549struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
550struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
551 int attrlen, int padattr);
552void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
553void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
554 const void *data);
555void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
556 const void *data, int padattr);
557void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
558int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
559int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
560 const void *data, int padattr);
561int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
562int nla_append(struct sk_buff *skb, int attrlen, const void *data);
563
564/**************************************************************************
565 * Netlink Messages
566 **************************************************************************/
567
568/**
569 * nlmsg_msg_size - length of netlink message not including padding
570 * @payload: length of message payload
571 */
572static inline int nlmsg_msg_size(int payload)
573{
574 return NLMSG_HDRLEN + payload;
575}
576
577/**
578 * nlmsg_total_size - length of netlink message including padding
579 * @payload: length of message payload
580 */
581static inline int nlmsg_total_size(int payload)
582{
583 return NLMSG_ALIGN(nlmsg_msg_size(payload));
584}
585
586/**
587 * nlmsg_padlen - length of padding at the message's tail
588 * @payload: length of message payload
589 */
590static inline int nlmsg_padlen(int payload)
591{
592 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
593}
594
595/**
596 * nlmsg_data - head of message payload
597 * @nlh: netlink message header
598 */
599static inline void *nlmsg_data(const struct nlmsghdr *nlh)
600{
601 return (unsigned char *) nlh + NLMSG_HDRLEN;
602}
603
604/**
605 * nlmsg_len - length of message payload
606 * @nlh: netlink message header
607 */
608static inline int nlmsg_len(const struct nlmsghdr *nlh)
609{
610 return nlh->nlmsg_len - NLMSG_HDRLEN;
611}
612
613/**
614 * nlmsg_attrdata - head of attributes data
615 * @nlh: netlink message header
616 * @hdrlen: length of family specific header
617 */
618static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
619 int hdrlen)
620{
621 unsigned char *data = nlmsg_data(nlh);
622 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
623}
624
625/**
626 * nlmsg_attrlen - length of attributes data
627 * @nlh: netlink message header
628 * @hdrlen: length of family specific header
629 */
630static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
631{
632 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
633}
634
635/**
636 * nlmsg_ok - check if the netlink message fits into the remaining bytes
637 * @nlh: netlink message header
638 * @remaining: number of bytes remaining in message stream
639 */
640static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
641{
642 return (remaining >= (int) sizeof(struct nlmsghdr) &&
643 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
644 nlh->nlmsg_len <= remaining);
645}
646
647/**
648 * nlmsg_next - next netlink message in message stream
649 * @nlh: netlink message header
650 * @remaining: number of bytes remaining in message stream
651 *
652 * Returns the next netlink message in the message stream and
653 * decrements remaining by the size of the current message.
654 */
655static inline struct nlmsghdr *
656nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
657{
658 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
659
660 *remaining -= totlen;
661
662 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
663}
664
665/**
666 * nla_parse - Parse a stream of attributes into a tb buffer
667 * @tb: destination array with maxtype+1 elements
668 * @maxtype: maximum attribute type to be expected
669 * @head: head of attribute stream
670 * @len: length of attribute stream
671 * @policy: validation policy
672 * @extack: extended ACK pointer
673 *
674 * Parses a stream of attributes and stores a pointer to each attribute in
675 * the tb array accessible via the attribute type. Attributes with a type
676 * exceeding maxtype will be rejected, policy must be specified, attributes
677 * will be validated in the strictest way possible.
678 *
679 * Returns 0 on success or a negative error code.
680 */
681static inline int nla_parse(struct nlattr **tb, int maxtype,
682 const struct nlattr *head, int len,
683 const struct nla_policy *policy,
684 struct netlink_ext_ack *extack)
685{
686 return __nla_parse(tb, maxtype, head, len, policy,
687 NL_VALIDATE_STRICT, extack);
688}
689
690/**
691 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
692 * @tb: destination array with maxtype+1 elements
693 * @maxtype: maximum attribute type to be expected
694 * @head: head of attribute stream
695 * @len: length of attribute stream
696 * @policy: validation policy
697 * @extack: extended ACK pointer
698 *
699 * Parses a stream of attributes and stores a pointer to each attribute in
700 * the tb array accessible via the attribute type. Attributes with a type
701 * exceeding maxtype will be ignored and attributes from the policy are not
702 * always strictly validated (only for new attributes).
703 *
704 * Returns 0 on success or a negative error code.
705 */
706static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
707 const struct nlattr *head, int len,
708 const struct nla_policy *policy,
709 struct netlink_ext_ack *extack)
710{
711 return __nla_parse(tb, maxtype, head, len, policy,
712 NL_VALIDATE_LIBERAL, extack);
713}
714
715/**
716 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
717 * @tb: destination array with maxtype+1 elements
718 * @maxtype: maximum attribute type to be expected
719 * @head: head of attribute stream
720 * @len: length of attribute stream
721 * @policy: validation policy
722 * @extack: extended ACK pointer
723 *
724 * Parses a stream of attributes and stores a pointer to each attribute in
725 * the tb array accessible via the attribute type. Attributes with a type
726 * exceeding maxtype will be rejected as well as trailing data, but the
727 * policy is not completely strictly validated (only for new attributes).
728 *
729 * Returns 0 on success or a negative error code.
730 */
731static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
732 const struct nlattr *head,
733 int len,
734 const struct nla_policy *policy,
735 struct netlink_ext_ack *extack)
736{
737 return __nla_parse(tb, maxtype, head, len, policy,
738 NL_VALIDATE_DEPRECATED_STRICT, extack);
739}
740
741/**
742 * __nlmsg_parse - parse attributes of a netlink message
743 * @nlh: netlink message header
744 * @hdrlen: length of family specific header
745 * @tb: destination array with maxtype+1 elements
746 * @maxtype: maximum attribute type to be expected
747 * @policy: validation policy
748 * @validate: validation strictness
749 * @extack: extended ACK report struct
750 *
751 * See nla_parse()
752 */
753static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
754 struct nlattr *tb[], int maxtype,
755 const struct nla_policy *policy,
756 unsigned int validate,
757 struct netlink_ext_ack *extack)
758{
759 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
760 NL_SET_ERR_MSG(extack, "Invalid header length");
761 return -EINVAL;
762 }
763
764 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
765 nlmsg_attrlen(nlh, hdrlen), policy, validate,
766 extack);
767}
768
769/**
770 * nlmsg_parse - parse attributes of a netlink message
771 * @nlh: netlink message header
772 * @hdrlen: length of family specific header
773 * @tb: destination array with maxtype+1 elements
774 * @maxtype: maximum attribute type to be expected
775 * @policy: validation policy
776 * @extack: extended ACK report struct
777 *
778 * See nla_parse()
779 */
780static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
781 struct nlattr *tb[], int maxtype,
782 const struct nla_policy *policy,
783 struct netlink_ext_ack *extack)
784{
785 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
786 NL_VALIDATE_STRICT, extack);
787}
788
789/**
790 * nlmsg_parse_deprecated - parse attributes of a netlink message
791 * @nlh: netlink message header
792 * @hdrlen: length of family specific header
793 * @tb: destination array with maxtype+1 elements
794 * @maxtype: maximum attribute type to be expected
795 * @policy: validation policy
796 * @extack: extended ACK report struct
797 *
798 * See nla_parse_deprecated()
799 */
800static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
801 struct nlattr *tb[], int maxtype,
802 const struct nla_policy *policy,
803 struct netlink_ext_ack *extack)
804{
805 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
806 NL_VALIDATE_LIBERAL, extack);
807}
808
809/**
810 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
811 * @nlh: netlink message header
812 * @hdrlen: length of family specific header
813 * @tb: destination array with maxtype+1 elements
814 * @maxtype: maximum attribute type to be expected
815 * @policy: validation policy
816 * @extack: extended ACK report struct
817 *
818 * See nla_parse_deprecated_strict()
819 */
820static inline int
821nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
822 struct nlattr *tb[], int maxtype,
823 const struct nla_policy *policy,
824 struct netlink_ext_ack *extack)
825{
826 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
827 NL_VALIDATE_DEPRECATED_STRICT, extack);
828}
829
830/**
831 * nlmsg_find_attr - find a specific attribute in a netlink message
832 * @nlh: netlink message header
833 * @hdrlen: length of family specific header
834 * @attrtype: type of attribute to look for
835 *
836 * Returns the first attribute which matches the specified type.
837 */
838static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
839 int hdrlen, int attrtype)
840{
841 return nla_find(nlmsg_attrdata(nlh, hdrlen),
842 nlmsg_attrlen(nlh, hdrlen), attrtype);
843}
844
845/**
846 * nla_validate_deprecated - Validate a stream of attributes
847 * @head: head of attribute stream
848 * @len: length of attribute stream
849 * @maxtype: maximum attribute type to be expected
850 * @policy: validation policy
851 * @extack: extended ACK report struct
852 *
853 * Validates all attributes in the specified attribute stream against the
854 * specified policy. Validation is done in liberal mode.
855 * See documentation of struct nla_policy for more details.
856 *
857 * Returns 0 on success or a negative error code.
858 */
859static inline int nla_validate_deprecated(const struct nlattr *head, int len,
860 int maxtype,
861 const struct nla_policy *policy,
862 struct netlink_ext_ack *extack)
863{
864 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
865 extack);
866}
867
868/**
869 * nla_validate - Validate a stream of attributes
870 * @head: head of attribute stream
871 * @len: length of attribute stream
872 * @maxtype: maximum attribute type to be expected
873 * @policy: validation policy
874 * @extack: extended ACK report struct
875 *
876 * Validates all attributes in the specified attribute stream against the
877 * specified policy. Validation is done in strict mode.
878 * See documentation of struct nla_policy for more details.
879 *
880 * Returns 0 on success or a negative error code.
881 */
882static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
883 const struct nla_policy *policy,
884 struct netlink_ext_ack *extack)
885{
886 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
887 extack);
888}
889
890/**
891 * nlmsg_validate_deprecated - validate a netlink message including attributes
892 * @nlh: netlinket message header
893 * @hdrlen: length of family specific header
894 * @maxtype: maximum attribute type to be expected
895 * @policy: validation policy
896 * @extack: extended ACK report struct
897 */
898static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
899 int hdrlen, int maxtype,
900 const struct nla_policy *policy,
901 struct netlink_ext_ack *extack)
902{
903 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
904 return -EINVAL;
905
906 return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
907 nlmsg_attrlen(nlh, hdrlen), maxtype,
908 policy, NL_VALIDATE_LIBERAL, extack);
909}
910
911
912
913/**
914 * nlmsg_report - need to report back to application?
915 * @nlh: netlink message header
916 *
917 * Returns 1 if a report back to the application is requested.
918 */
919static inline int nlmsg_report(const struct nlmsghdr *nlh)
920{
921 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
922}
923
924/**
925 * nlmsg_seq - return the seq number of netlink message
926 * @nlh: netlink message header
927 *
928 * Returns 0 if netlink message is NULL
929 */
930static inline u32 nlmsg_seq(const struct nlmsghdr *nlh)
931{
932 return nlh ? nlh->nlmsg_seq : 0;
933}
934
935/**
936 * nlmsg_for_each_attr - iterate over a stream of attributes
937 * @pos: loop counter, set to current attribute
938 * @nlh: netlink message header
939 * @hdrlen: length of family specific header
940 * @rem: initialized to len, holds bytes currently remaining in stream
941 */
942#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
943 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
944 nlmsg_attrlen(nlh, hdrlen), rem)
945
946/**
947 * nlmsg_put - Add a new netlink message to an skb
948 * @skb: socket buffer to store message in
949 * @portid: netlink PORTID of requesting application
950 * @seq: sequence number of message
951 * @type: message type
952 * @payload: length of message payload
953 * @flags: message flags
954 *
955 * Returns NULL if the tailroom of the skb is insufficient to store
956 * the message header and payload.
957 */
958static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
959 int type, int payload, int flags)
960{
961 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
962 return NULL;
963
964 return __nlmsg_put(skb, portid, seq, type, payload, flags);
965}
966
967/**
968 * nlmsg_append - Add more data to a nlmsg in a skb
969 * @skb: socket buffer to store message in
970 * @size: length of message payload
971 *
972 * Append data to an existing nlmsg, used when constructing a message
973 * with multiple fixed-format headers (which is rare).
974 * Returns NULL if the tailroom of the skb is insufficient to store
975 * the extra payload.
976 */
977static inline void *nlmsg_append(struct sk_buff *skb, u32 size)
978{
979 if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size)))
980 return NULL;
981
982 if (NLMSG_ALIGN(size) - size)
983 memset(skb_tail_pointer(skb) + size, 0,
984 NLMSG_ALIGN(size) - size);
985 return __skb_put(skb, NLMSG_ALIGN(size));
986}
987
988/**
989 * nlmsg_put_answer - Add a new callback based netlink message to an skb
990 * @skb: socket buffer to store message in
991 * @cb: netlink callback
992 * @type: message type
993 * @payload: length of message payload
994 * @flags: message flags
995 *
996 * Returns NULL if the tailroom of the skb is insufficient to store
997 * the message header and payload.
998 */
999static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
1000 struct netlink_callback *cb,
1001 int type, int payload,
1002 int flags)
1003{
1004 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1005 type, payload, flags);
1006}
1007
1008/**
1009 * nlmsg_new - Allocate a new netlink message
1010 * @payload: size of the message payload
1011 * @flags: the type of memory to allocate.
1012 *
1013 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
1014 * and a good default is needed.
1015 */
1016static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
1017{
1018 return alloc_skb(nlmsg_total_size(payload), flags);
1019}
1020
1021/**
1022 * nlmsg_new_large - Allocate a new netlink message with non-contiguous
1023 * physical memory
1024 * @payload: size of the message payload
1025 *
1026 * The allocated skb is unable to have frag page for shinfo->frags*,
1027 * as the NULL setting for skb->head in netlink_skb_destructor() will
1028 * bypass most of the handling in skb_release_data()
1029 */
1030static inline struct sk_buff *nlmsg_new_large(size_t payload)
1031{
1032 return netlink_alloc_large_skb(nlmsg_total_size(payload), 0);
1033}
1034
1035/**
1036 * nlmsg_end - Finalize a netlink message
1037 * @skb: socket buffer the message is stored in
1038 * @nlh: netlink message header
1039 *
1040 * Corrects the netlink message header to include the appended
1041 * attributes. Only necessary if attributes have been added to
1042 * the message.
1043 */
1044static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
1045{
1046 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
1047}
1048
1049/**
1050 * nlmsg_get_pos - return current position in netlink message
1051 * @skb: socket buffer the message is stored in
1052 *
1053 * Returns a pointer to the current tail of the message.
1054 */
1055static inline void *nlmsg_get_pos(struct sk_buff *skb)
1056{
1057 return skb_tail_pointer(skb);
1058}
1059
1060/**
1061 * nlmsg_trim - Trim message to a mark
1062 * @skb: socket buffer the message is stored in
1063 * @mark: mark to trim to
1064 *
1065 * Trims the message to the provided mark.
1066 */
1067static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1068{
1069 if (mark) {
1070 WARN_ON((unsigned char *) mark < skb->data);
1071 skb_trim(skb, (unsigned char *) mark - skb->data);
1072 }
1073}
1074
1075/**
1076 * nlmsg_cancel - Cancel construction of a netlink message
1077 * @skb: socket buffer the message is stored in
1078 * @nlh: netlink message header
1079 *
1080 * Removes the complete netlink message including all
1081 * attributes from the socket buffer again.
1082 */
1083static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1084{
1085 nlmsg_trim(skb, nlh);
1086}
1087
1088/**
1089 * nlmsg_free - drop a netlink message
1090 * @skb: socket buffer of netlink message
1091 */
1092static inline void nlmsg_free(struct sk_buff *skb)
1093{
1094 kfree_skb(skb);
1095}
1096
1097/**
1098 * nlmsg_consume - free a netlink message
1099 * @skb: socket buffer of netlink message
1100 */
1101static inline void nlmsg_consume(struct sk_buff *skb)
1102{
1103 consume_skb(skb);
1104}
1105
1106/**
1107 * nlmsg_multicast_filtered - multicast a netlink message with filter function
1108 * @sk: netlink socket to spread messages to
1109 * @skb: netlink message as socket buffer
1110 * @portid: own netlink portid to avoid sending to yourself
1111 * @group: multicast group id
1112 * @flags: allocation flags
1113 * @filter: filter function
1114 * @filter_data: filter function private data
1115 *
1116 * Return: 0 on success, negative error code for failure.
1117 */
1118static inline int nlmsg_multicast_filtered(struct sock *sk, struct sk_buff *skb,
1119 u32 portid, unsigned int group,
1120 gfp_t flags,
1121 netlink_filter_fn filter,
1122 void *filter_data)
1123{
1124 int err;
1125
1126 NETLINK_CB(skb).dst_group = group;
1127
1128 err = netlink_broadcast_filtered(sk, skb, portid, group, flags,
1129 filter, filter_data);
1130 if (err > 0)
1131 err = 0;
1132
1133 return err;
1134}
1135
1136/**
1137 * nlmsg_multicast - multicast a netlink message
1138 * @sk: netlink socket to spread messages to
1139 * @skb: netlink message as socket buffer
1140 * @portid: own netlink portid to avoid sending to yourself
1141 * @group: multicast group id
1142 * @flags: allocation flags
1143 */
1144static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1145 u32 portid, unsigned int group, gfp_t flags)
1146{
1147 return nlmsg_multicast_filtered(sk, skb, portid, group, flags,
1148 NULL, NULL);
1149}
1150
1151/**
1152 * nlmsg_unicast - unicast a netlink message
1153 * @sk: netlink socket to spread message to
1154 * @skb: netlink message as socket buffer
1155 * @portid: netlink portid of the destination socket
1156 */
1157static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1158{
1159 int err;
1160
1161 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1162 if (err > 0)
1163 err = 0;
1164
1165 return err;
1166}
1167
1168/**
1169 * nlmsg_for_each_msg - iterate over a stream of messages
1170 * @pos: loop counter, set to current message
1171 * @head: head of message stream
1172 * @len: length of message stream
1173 * @rem: initialized to len, holds bytes currently remaining in stream
1174 */
1175#define nlmsg_for_each_msg(pos, head, len, rem) \
1176 for (pos = head, rem = len; \
1177 nlmsg_ok(pos, rem); \
1178 pos = nlmsg_next(pos, &(rem)))
1179
1180/**
1181 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1182 * @cb: netlink callback structure that stores the sequence number
1183 * @nlh: netlink message header to write the flag to
1184 *
1185 * This function checks if the sequence (generation) number changed during dump
1186 * and if it did, advertises it in the netlink message header.
1187 *
1188 * The correct way to use it is to set cb->seq to the generation counter when
1189 * all locks for dumping have been acquired, and then call this function for
1190 * each message that is generated.
1191 *
1192 * Note that due to initialisation concerns, 0 is an invalid sequence number
1193 * and must not be used by code that uses this functionality.
1194 */
1195static inline void
1196nl_dump_check_consistent(struct netlink_callback *cb,
1197 struct nlmsghdr *nlh)
1198{
1199 if (cb->prev_seq && cb->seq != cb->prev_seq)
1200 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1201 cb->prev_seq = cb->seq;
1202}
1203
1204/**************************************************************************
1205 * Netlink Attributes
1206 **************************************************************************/
1207
1208/**
1209 * nla_attr_size - length of attribute not including padding
1210 * @payload: length of payload
1211 */
1212static inline int nla_attr_size(int payload)
1213{
1214 return NLA_HDRLEN + payload;
1215}
1216
1217/**
1218 * nla_total_size - total length of attribute including padding
1219 * @payload: length of payload
1220 */
1221static inline int nla_total_size(int payload)
1222{
1223 return NLA_ALIGN(nla_attr_size(payload));
1224}
1225
1226/**
1227 * nla_padlen - length of padding at the tail of attribute
1228 * @payload: length of payload
1229 */
1230static inline int nla_padlen(int payload)
1231{
1232 return nla_total_size(payload) - nla_attr_size(payload);
1233}
1234
1235/**
1236 * nla_type - attribute type
1237 * @nla: netlink attribute
1238 */
1239static inline int nla_type(const struct nlattr *nla)
1240{
1241 return nla->nla_type & NLA_TYPE_MASK;
1242}
1243
1244/**
1245 * nla_data - head of payload
1246 * @nla: netlink attribute
1247 */
1248static inline void *nla_data(const struct nlattr *nla)
1249{
1250 return (char *) nla + NLA_HDRLEN;
1251}
1252
1253/**
1254 * nla_len - length of payload
1255 * @nla: netlink attribute
1256 */
1257static inline u16 nla_len(const struct nlattr *nla)
1258{
1259 return nla->nla_len - NLA_HDRLEN;
1260}
1261
1262/**
1263 * nla_ok - check if the netlink attribute fits into the remaining bytes
1264 * @nla: netlink attribute
1265 * @remaining: number of bytes remaining in attribute stream
1266 */
1267static inline int nla_ok(const struct nlattr *nla, int remaining)
1268{
1269 return remaining >= (int) sizeof(*nla) &&
1270 nla->nla_len >= sizeof(*nla) &&
1271 nla->nla_len <= remaining;
1272}
1273
1274/**
1275 * nla_next - next netlink attribute in attribute stream
1276 * @nla: netlink attribute
1277 * @remaining: number of bytes remaining in attribute stream
1278 *
1279 * Returns the next netlink attribute in the attribute stream and
1280 * decrements remaining by the size of the current attribute.
1281 */
1282static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1283{
1284 unsigned int totlen = NLA_ALIGN(nla->nla_len);
1285
1286 *remaining -= totlen;
1287 return (struct nlattr *) ((char *) nla + totlen);
1288}
1289
1290/**
1291 * nla_find_nested - find attribute in a set of nested attributes
1292 * @nla: attribute containing the nested attributes
1293 * @attrtype: type of attribute to look for
1294 *
1295 * Returns the first attribute which matches the specified type.
1296 */
1297static inline struct nlattr *
1298nla_find_nested(const struct nlattr *nla, int attrtype)
1299{
1300 return nla_find(nla_data(nla), nla_len(nla), attrtype);
1301}
1302
1303/**
1304 * nla_parse_nested - parse nested attributes
1305 * @tb: destination array with maxtype+1 elements
1306 * @maxtype: maximum attribute type to be expected
1307 * @nla: attribute containing the nested attributes
1308 * @policy: validation policy
1309 * @extack: extended ACK report struct
1310 *
1311 * See nla_parse()
1312 */
1313static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1314 const struct nlattr *nla,
1315 const struct nla_policy *policy,
1316 struct netlink_ext_ack *extack)
1317{
1318 if (!(nla->nla_type & NLA_F_NESTED)) {
1319 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1320 return -EINVAL;
1321 }
1322
1323 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1324 NL_VALIDATE_STRICT, extack);
1325}
1326
1327/**
1328 * nla_parse_nested_deprecated - parse nested attributes
1329 * @tb: destination array with maxtype+1 elements
1330 * @maxtype: maximum attribute type to be expected
1331 * @nla: attribute containing the nested attributes
1332 * @policy: validation policy
1333 * @extack: extended ACK report struct
1334 *
1335 * See nla_parse_deprecated()
1336 */
1337static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1338 const struct nlattr *nla,
1339 const struct nla_policy *policy,
1340 struct netlink_ext_ack *extack)
1341{
1342 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1343 NL_VALIDATE_LIBERAL, extack);
1344}
1345
1346/**
1347 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1348 * @skb: socket buffer to add attribute to
1349 * @attrtype: attribute type
1350 * @value: numeric value
1351 */
1352static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1353{
1354 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
1355 u8 tmp = value;
1356
1357 return nla_put(skb, attrtype, sizeof(u8), &tmp);
1358}
1359
1360/**
1361 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1362 * @skb: socket buffer to add attribute to
1363 * @attrtype: attribute type
1364 * @value: numeric value
1365 */
1366static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1367{
1368 u16 tmp = value;
1369
1370 return nla_put(skb, attrtype, sizeof(u16), &tmp);
1371}
1372
1373/**
1374 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1375 * @skb: socket buffer to add attribute to
1376 * @attrtype: attribute type
1377 * @value: numeric value
1378 */
1379static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1380{
1381 __be16 tmp = value;
1382
1383 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1384}
1385
1386/**
1387 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1388 * @skb: socket buffer to add attribute to
1389 * @attrtype: attribute type
1390 * @value: numeric value
1391 */
1392static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1393{
1394 __be16 tmp = value;
1395
1396 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1397}
1398
1399/**
1400 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1401 * @skb: socket buffer to add attribute to
1402 * @attrtype: attribute type
1403 * @value: numeric value
1404 */
1405static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1406{
1407 __le16 tmp = value;
1408
1409 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1410}
1411
1412/**
1413 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1414 * @skb: socket buffer to add attribute to
1415 * @attrtype: attribute type
1416 * @value: numeric value
1417 */
1418static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1419{
1420 u32 tmp = value;
1421
1422 return nla_put(skb, attrtype, sizeof(u32), &tmp);
1423}
1424
1425/**
1426 * nla_put_uint - Add a variable-size unsigned int to a socket buffer
1427 * @skb: socket buffer to add attribute to
1428 * @attrtype: attribute type
1429 * @value: numeric value
1430 */
1431static inline int nla_put_uint(struct sk_buff *skb, int attrtype, u64 value)
1432{
1433 u64 tmp64 = value;
1434 u32 tmp32 = value;
1435
1436 if (tmp64 == tmp32)
1437 return nla_put_u32(skb, attrtype, tmp32);
1438 return nla_put(skb, attrtype, sizeof(u64), &tmp64);
1439}
1440
1441/**
1442 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1443 * @skb: socket buffer to add attribute to
1444 * @attrtype: attribute type
1445 * @value: numeric value
1446 */
1447static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1448{
1449 __be32 tmp = value;
1450
1451 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1452}
1453
1454/**
1455 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1456 * @skb: socket buffer to add attribute to
1457 * @attrtype: attribute type
1458 * @value: numeric value
1459 */
1460static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1461{
1462 __be32 tmp = value;
1463
1464 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1465}
1466
1467/**
1468 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1469 * @skb: socket buffer to add attribute to
1470 * @attrtype: attribute type
1471 * @value: numeric value
1472 */
1473static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1474{
1475 __le32 tmp = value;
1476
1477 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1478}
1479
1480/**
1481 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1482 * @skb: socket buffer to add attribute to
1483 * @attrtype: attribute type
1484 * @value: numeric value
1485 * @padattr: attribute type for the padding
1486 */
1487static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1488 u64 value, int padattr)
1489{
1490 u64 tmp = value;
1491
1492 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1493}
1494
1495/**
1496 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1497 * @skb: socket buffer to add attribute to
1498 * @attrtype: attribute type
1499 * @value: numeric value
1500 * @padattr: attribute type for the padding
1501 */
1502static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1503 int padattr)
1504{
1505 __be64 tmp = value;
1506
1507 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1508}
1509
1510/**
1511 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1512 * @skb: socket buffer to add attribute to
1513 * @attrtype: attribute type
1514 * @value: numeric value
1515 * @padattr: attribute type for the padding
1516 */
1517static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1518 int padattr)
1519{
1520 __be64 tmp = value;
1521
1522 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1523 padattr);
1524}
1525
1526/**
1527 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1528 * @skb: socket buffer to add attribute to
1529 * @attrtype: attribute type
1530 * @value: numeric value
1531 * @padattr: attribute type for the padding
1532 */
1533static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1534 int padattr)
1535{
1536 __le64 tmp = value;
1537
1538 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1539}
1540
1541/**
1542 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1543 * @skb: socket buffer to add attribute to
1544 * @attrtype: attribute type
1545 * @value: numeric value
1546 */
1547static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1548{
1549 s8 tmp = value;
1550
1551 return nla_put(skb, attrtype, sizeof(s8), &tmp);
1552}
1553
1554/**
1555 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1556 * @skb: socket buffer to add attribute to
1557 * @attrtype: attribute type
1558 * @value: numeric value
1559 */
1560static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1561{
1562 s16 tmp = value;
1563
1564 return nla_put(skb, attrtype, sizeof(s16), &tmp);
1565}
1566
1567/**
1568 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1569 * @skb: socket buffer to add attribute to
1570 * @attrtype: attribute type
1571 * @value: numeric value
1572 */
1573static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1574{
1575 s32 tmp = value;
1576
1577 return nla_put(skb, attrtype, sizeof(s32), &tmp);
1578}
1579
1580/**
1581 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1582 * @skb: socket buffer to add attribute to
1583 * @attrtype: attribute type
1584 * @value: numeric value
1585 * @padattr: attribute type for the padding
1586 */
1587static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1588 int padattr)
1589{
1590 s64 tmp = value;
1591
1592 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1593}
1594
1595/**
1596 * nla_put_sint - Add a variable-size signed int to a socket buffer
1597 * @skb: socket buffer to add attribute to
1598 * @attrtype: attribute type
1599 * @value: numeric value
1600 */
1601static inline int nla_put_sint(struct sk_buff *skb, int attrtype, s64 value)
1602{
1603 s64 tmp64 = value;
1604 s32 tmp32 = value;
1605
1606 if (tmp64 == tmp32)
1607 return nla_put_s32(skb, attrtype, tmp32);
1608 return nla_put(skb, attrtype, sizeof(s64), &tmp64);
1609}
1610
1611/**
1612 * nla_put_string - Add a string netlink attribute to a socket buffer
1613 * @skb: socket buffer to add attribute to
1614 * @attrtype: attribute type
1615 * @str: NUL terminated string
1616 */
1617static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1618 const char *str)
1619{
1620 return nla_put(skb, attrtype, strlen(str) + 1, str);
1621}
1622
1623/**
1624 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1625 * @skb: socket buffer to add attribute to
1626 * @attrtype: attribute type
1627 */
1628static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1629{
1630 return nla_put(skb, attrtype, 0, NULL);
1631}
1632
1633/**
1634 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1635 * @skb: socket buffer to add attribute to
1636 * @attrtype: attribute type
1637 * @njiffies: number of jiffies to convert to msecs
1638 * @padattr: attribute type for the padding
1639 */
1640static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1641 unsigned long njiffies, int padattr)
1642{
1643 u64 tmp = jiffies_to_msecs(njiffies);
1644
1645 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1646}
1647
1648/**
1649 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1650 * buffer
1651 * @skb: socket buffer to add attribute to
1652 * @attrtype: attribute type
1653 * @addr: IPv4 address
1654 */
1655static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1656 __be32 addr)
1657{
1658 __be32 tmp = addr;
1659
1660 return nla_put_be32(skb, attrtype, tmp);
1661}
1662
1663/**
1664 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1665 * buffer
1666 * @skb: socket buffer to add attribute to
1667 * @attrtype: attribute type
1668 * @addr: IPv6 address
1669 */
1670static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1671 const struct in6_addr *addr)
1672{
1673 return nla_put(skb, attrtype, sizeof(*addr), addr);
1674}
1675
1676/**
1677 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1678 * @skb: socket buffer to add attribute to
1679 * @attrtype: attribute type
1680 * @value: value carrying bits
1681 * @selector: selector of valid bits
1682 */
1683static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1684 __u32 value, __u32 selector)
1685{
1686 struct nla_bitfield32 tmp = { value, selector, };
1687
1688 return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1689}
1690
1691/**
1692 * nla_get_u32 - return payload of u32 attribute
1693 * @nla: u32 netlink attribute
1694 */
1695static inline u32 nla_get_u32(const struct nlattr *nla)
1696{
1697 return *(u32 *) nla_data(nla);
1698}
1699
1700/**
1701 * nla_get_u32_default - return payload of u32 attribute or default
1702 * @nla: u32 netlink attribute, may be %NULL
1703 * @defvalue: default value to use if @nla is %NULL
1704 *
1705 * Return: the value of the attribute, or the default value if not present
1706 */
1707static inline u32 nla_get_u32_default(const struct nlattr *nla, u32 defvalue)
1708{
1709 if (!nla)
1710 return defvalue;
1711 return nla_get_u32(nla);
1712}
1713
1714/**
1715 * nla_get_be32 - return payload of __be32 attribute
1716 * @nla: __be32 netlink attribute
1717 */
1718static inline __be32 nla_get_be32(const struct nlattr *nla)
1719{
1720 return *(__be32 *) nla_data(nla);
1721}
1722
1723/**
1724 * nla_get_be32_default - return payload of be32 attribute or default
1725 * @nla: __be32 netlink attribute, may be %NULL
1726 * @defvalue: default value to use if @nla is %NULL
1727 *
1728 * Return: the value of the attribute, or the default value if not present
1729 */
1730static inline __be32 nla_get_be32_default(const struct nlattr *nla,
1731 __be32 defvalue)
1732{
1733 if (!nla)
1734 return defvalue;
1735 return nla_get_be32(nla);
1736}
1737
1738/**
1739 * nla_get_le32 - return payload of __le32 attribute
1740 * @nla: __le32 netlink attribute
1741 */
1742static inline __le32 nla_get_le32(const struct nlattr *nla)
1743{
1744 return *(__le32 *) nla_data(nla);
1745}
1746
1747/**
1748 * nla_get_le32_default - return payload of le32 attribute or default
1749 * @nla: __le32 netlink attribute, may be %NULL
1750 * @defvalue: default value to use if @nla is %NULL
1751 *
1752 * Return: the value of the attribute, or the default value if not present
1753 */
1754static inline __le32 nla_get_le32_default(const struct nlattr *nla,
1755 __le32 defvalue)
1756{
1757 if (!nla)
1758 return defvalue;
1759 return nla_get_le32(nla);
1760}
1761
1762/**
1763 * nla_get_u16 - return payload of u16 attribute
1764 * @nla: u16 netlink attribute
1765 */
1766static inline u16 nla_get_u16(const struct nlattr *nla)
1767{
1768 return *(u16 *) nla_data(nla);
1769}
1770
1771/**
1772 * nla_get_u16_default - return payload of u16 attribute or default
1773 * @nla: u16 netlink attribute, may be %NULL
1774 * @defvalue: default value to use if @nla is %NULL
1775 *
1776 * Return: the value of the attribute, or the default value if not present
1777 */
1778static inline u16 nla_get_u16_default(const struct nlattr *nla, u16 defvalue)
1779{
1780 if (!nla)
1781 return defvalue;
1782 return nla_get_u16(nla);
1783}
1784
1785/**
1786 * nla_get_be16 - return payload of __be16 attribute
1787 * @nla: __be16 netlink attribute
1788 */
1789static inline __be16 nla_get_be16(const struct nlattr *nla)
1790{
1791 return *(__be16 *) nla_data(nla);
1792}
1793
1794/**
1795 * nla_get_be16_default - return payload of be16 attribute or default
1796 * @nla: __be16 netlink attribute, may be %NULL
1797 * @defvalue: default value to use if @nla is %NULL
1798 *
1799 * Return: the value of the attribute, or the default value if not present
1800 */
1801static inline __be16 nla_get_be16_default(const struct nlattr *nla,
1802 __be16 defvalue)
1803{
1804 if (!nla)
1805 return defvalue;
1806 return nla_get_be16(nla);
1807}
1808
1809/**
1810 * nla_get_le16 - return payload of __le16 attribute
1811 * @nla: __le16 netlink attribute
1812 */
1813static inline __le16 nla_get_le16(const struct nlattr *nla)
1814{
1815 return *(__le16 *) nla_data(nla);
1816}
1817
1818/**
1819 * nla_get_le16_default - return payload of le16 attribute or default
1820 * @nla: __le16 netlink attribute, may be %NULL
1821 * @defvalue: default value to use if @nla is %NULL
1822 *
1823 * Return: the value of the attribute, or the default value if not present
1824 */
1825static inline __le16 nla_get_le16_default(const struct nlattr *nla,
1826 __le16 defvalue)
1827{
1828 if (!nla)
1829 return defvalue;
1830 return nla_get_le16(nla);
1831}
1832
1833/**
1834 * nla_get_u8 - return payload of u8 attribute
1835 * @nla: u8 netlink attribute
1836 */
1837static inline u8 nla_get_u8(const struct nlattr *nla)
1838{
1839 return *(u8 *) nla_data(nla);
1840}
1841
1842/**
1843 * nla_get_u8_default - return payload of u8 attribute or default
1844 * @nla: u8 netlink attribute, may be %NULL
1845 * @defvalue: default value to use if @nla is %NULL
1846 *
1847 * Return: the value of the attribute, or the default value if not present
1848 */
1849static inline u8 nla_get_u8_default(const struct nlattr *nla, u8 defvalue)
1850{
1851 if (!nla)
1852 return defvalue;
1853 return nla_get_u8(nla);
1854}
1855
1856/**
1857 * nla_get_u64 - return payload of u64 attribute
1858 * @nla: u64 netlink attribute
1859 */
1860static inline u64 nla_get_u64(const struct nlattr *nla)
1861{
1862 u64 tmp;
1863
1864 nla_memcpy(&tmp, nla, sizeof(tmp));
1865
1866 return tmp;
1867}
1868
1869/**
1870 * nla_get_u64_default - return payload of u64 attribute or default
1871 * @nla: u64 netlink attribute, may be %NULL
1872 * @defvalue: default value to use if @nla is %NULL
1873 *
1874 * Return: the value of the attribute, or the default value if not present
1875 */
1876static inline u64 nla_get_u64_default(const struct nlattr *nla, u64 defvalue)
1877{
1878 if (!nla)
1879 return defvalue;
1880 return nla_get_u64(nla);
1881}
1882
1883/**
1884 * nla_get_uint - return payload of uint attribute
1885 * @nla: uint netlink attribute
1886 */
1887static inline u64 nla_get_uint(const struct nlattr *nla)
1888{
1889 if (nla_len(nla) == sizeof(u32))
1890 return nla_get_u32(nla);
1891 return nla_get_u64(nla);
1892}
1893
1894/**
1895 * nla_get_uint_default - return payload of uint attribute or default
1896 * @nla: uint netlink attribute, may be %NULL
1897 * @defvalue: default value to use if @nla is %NULL
1898 *
1899 * Return: the value of the attribute, or the default value if not present
1900 */
1901static inline u64 nla_get_uint_default(const struct nlattr *nla, u64 defvalue)
1902{
1903 if (!nla)
1904 return defvalue;
1905 return nla_get_uint(nla);
1906}
1907
1908/**
1909 * nla_get_be64 - return payload of __be64 attribute
1910 * @nla: __be64 netlink attribute
1911 */
1912static inline __be64 nla_get_be64(const struct nlattr *nla)
1913{
1914 __be64 tmp;
1915
1916 nla_memcpy(&tmp, nla, sizeof(tmp));
1917
1918 return tmp;
1919}
1920
1921/**
1922 * nla_get_be64_default - return payload of be64 attribute or default
1923 * @nla: __be64 netlink attribute, may be %NULL
1924 * @defvalue: default value to use if @nla is %NULL
1925 *
1926 * Return: the value of the attribute, or the default value if not present
1927 */
1928static inline __be64 nla_get_be64_default(const struct nlattr *nla,
1929 __be64 defvalue)
1930{
1931 if (!nla)
1932 return defvalue;
1933 return nla_get_be64(nla);
1934}
1935
1936/**
1937 * nla_get_le64 - return payload of __le64 attribute
1938 * @nla: __le64 netlink attribute
1939 */
1940static inline __le64 nla_get_le64(const struct nlattr *nla)
1941{
1942 return *(__le64 *) nla_data(nla);
1943}
1944
1945/**
1946 * nla_get_le64_default - return payload of le64 attribute or default
1947 * @nla: __le64 netlink attribute, may be %NULL
1948 * @defvalue: default value to use if @nla is %NULL
1949 *
1950 * Return: the value of the attribute, or the default value if not present
1951 */
1952static inline __le64 nla_get_le64_default(const struct nlattr *nla,
1953 __le64 defvalue)
1954{
1955 if (!nla)
1956 return defvalue;
1957 return nla_get_le64(nla);
1958}
1959
1960/**
1961 * nla_get_s32 - return payload of s32 attribute
1962 * @nla: s32 netlink attribute
1963 */
1964static inline s32 nla_get_s32(const struct nlattr *nla)
1965{
1966 return *(s32 *) nla_data(nla);
1967}
1968
1969/**
1970 * nla_get_s32_default - return payload of s32 attribute or default
1971 * @nla: s32 netlink attribute, may be %NULL
1972 * @defvalue: default value to use if @nla is %NULL
1973 *
1974 * Return: the value of the attribute, or the default value if not present
1975 */
1976static inline s32 nla_get_s32_default(const struct nlattr *nla, s32 defvalue)
1977{
1978 if (!nla)
1979 return defvalue;
1980 return nla_get_s32(nla);
1981}
1982
1983/**
1984 * nla_get_s16 - return payload of s16 attribute
1985 * @nla: s16 netlink attribute
1986 */
1987static inline s16 nla_get_s16(const struct nlattr *nla)
1988{
1989 return *(s16 *) nla_data(nla);
1990}
1991
1992/**
1993 * nla_get_s16_default - return payload of s16 attribute or default
1994 * @nla: s16 netlink attribute, may be %NULL
1995 * @defvalue: default value to use if @nla is %NULL
1996 *
1997 * Return: the value of the attribute, or the default value if not present
1998 */
1999static inline s16 nla_get_s16_default(const struct nlattr *nla, s16 defvalue)
2000{
2001 if (!nla)
2002 return defvalue;
2003 return nla_get_s16(nla);
2004}
2005
2006/**
2007 * nla_get_s8 - return payload of s8 attribute
2008 * @nla: s8 netlink attribute
2009 */
2010static inline s8 nla_get_s8(const struct nlattr *nla)
2011{
2012 return *(s8 *) nla_data(nla);
2013}
2014
2015/**
2016 * nla_get_s8_default - return payload of s8 attribute or default
2017 * @nla: s8 netlink attribute, may be %NULL
2018 * @defvalue: default value to use if @nla is %NULL
2019 *
2020 * Return: the value of the attribute, or the default value if not present
2021 */
2022static inline s8 nla_get_s8_default(const struct nlattr *nla, s8 defvalue)
2023{
2024 if (!nla)
2025 return defvalue;
2026 return nla_get_s8(nla);
2027}
2028
2029/**
2030 * nla_get_s64 - return payload of s64 attribute
2031 * @nla: s64 netlink attribute
2032 */
2033static inline s64 nla_get_s64(const struct nlattr *nla)
2034{
2035 s64 tmp;
2036
2037 nla_memcpy(&tmp, nla, sizeof(tmp));
2038
2039 return tmp;
2040}
2041
2042/**
2043 * nla_get_s64_default - return payload of s64 attribute or default
2044 * @nla: s64 netlink attribute, may be %NULL
2045 * @defvalue: default value to use if @nla is %NULL
2046 *
2047 * Return: the value of the attribute, or the default value if not present
2048 */
2049static inline s64 nla_get_s64_default(const struct nlattr *nla, s64 defvalue)
2050{
2051 if (!nla)
2052 return defvalue;
2053 return nla_get_s64(nla);
2054}
2055
2056/**
2057 * nla_get_sint - return payload of uint attribute
2058 * @nla: uint netlink attribute
2059 */
2060static inline s64 nla_get_sint(const struct nlattr *nla)
2061{
2062 if (nla_len(nla) == sizeof(s32))
2063 return nla_get_s32(nla);
2064 return nla_get_s64(nla);
2065}
2066
2067/**
2068 * nla_get_sint_default - return payload of sint attribute or default
2069 * @nla: sint netlink attribute, may be %NULL
2070 * @defvalue: default value to use if @nla is %NULL
2071 *
2072 * Return: the value of the attribute, or the default value if not present
2073 */
2074static inline s64 nla_get_sint_default(const struct nlattr *nla, s64 defvalue)
2075{
2076 if (!nla)
2077 return defvalue;
2078 return nla_get_sint(nla);
2079}
2080
2081/**
2082 * nla_get_flag - return payload of flag attribute
2083 * @nla: flag netlink attribute
2084 */
2085static inline int nla_get_flag(const struct nlattr *nla)
2086{
2087 return !!nla;
2088}
2089
2090/**
2091 * nla_get_msecs - return payload of msecs attribute
2092 * @nla: msecs netlink attribute
2093 *
2094 * Returns the number of milliseconds in jiffies.
2095 */
2096static inline unsigned long nla_get_msecs(const struct nlattr *nla)
2097{
2098 u64 msecs = nla_get_u64(nla);
2099
2100 return msecs_to_jiffies((unsigned long) msecs);
2101}
2102
2103/**
2104 * nla_get_msecs_default - return payload of msecs attribute or default
2105 * @nla: msecs netlink attribute, may be %NULL
2106 * @defvalue: default value to use if @nla is %NULL
2107 *
2108 * Return: the value of the attribute, or the default value if not present
2109 */
2110static inline unsigned long nla_get_msecs_default(const struct nlattr *nla,
2111 unsigned long defvalue)
2112{
2113 if (!nla)
2114 return defvalue;
2115 return nla_get_msecs(nla);
2116}
2117
2118/**
2119 * nla_get_in_addr - return payload of IPv4 address attribute
2120 * @nla: IPv4 address netlink attribute
2121 */
2122static inline __be32 nla_get_in_addr(const struct nlattr *nla)
2123{
2124 return *(__be32 *) nla_data(nla);
2125}
2126
2127/**
2128 * nla_get_in_addr_default - return payload of be32 attribute or default
2129 * @nla: IPv4 address netlink attribute, may be %NULL
2130 * @defvalue: default value to use if @nla is %NULL
2131 *
2132 * Return: the value of the attribute, or the default value if not present
2133 */
2134static inline __be32 nla_get_in_addr_default(const struct nlattr *nla,
2135 __be32 defvalue)
2136{
2137 if (!nla)
2138 return defvalue;
2139 return nla_get_in_addr(nla);
2140}
2141
2142/**
2143 * nla_get_in6_addr - return payload of IPv6 address attribute
2144 * @nla: IPv6 address netlink attribute
2145 */
2146static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
2147{
2148 struct in6_addr tmp;
2149
2150 nla_memcpy(&tmp, nla, sizeof(tmp));
2151 return tmp;
2152}
2153
2154/**
2155 * nla_get_bitfield32 - return payload of 32 bitfield attribute
2156 * @nla: nla_bitfield32 attribute
2157 */
2158static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
2159{
2160 struct nla_bitfield32 tmp;
2161
2162 nla_memcpy(&tmp, nla, sizeof(tmp));
2163 return tmp;
2164}
2165
2166/**
2167 * nla_memdup - duplicate attribute memory (kmemdup)
2168 * @src: netlink attribute to duplicate from
2169 * @gfp: GFP mask
2170 */
2171static inline void *nla_memdup_noprof(const struct nlattr *src, gfp_t gfp)
2172{
2173 return kmemdup_noprof(nla_data(src), nla_len(src), gfp);
2174}
2175#define nla_memdup(...) alloc_hooks(nla_memdup_noprof(__VA_ARGS__))
2176
2177/**
2178 * nla_nest_start_noflag - Start a new level of nested attributes
2179 * @skb: socket buffer to add attributes to
2180 * @attrtype: attribute type of container
2181 *
2182 * This function exists for backward compatibility to use in APIs which never
2183 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
2184 * nla_nest_start() which sets the flag.
2185 *
2186 * Returns the container attribute or NULL on error
2187 */
2188static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
2189 int attrtype)
2190{
2191 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
2192
2193 if (nla_put(skb, attrtype, 0, NULL) < 0)
2194 return NULL;
2195
2196 return start;
2197}
2198
2199/**
2200 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
2201 * @skb: socket buffer to add attributes to
2202 * @attrtype: attribute type of container
2203 *
2204 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
2205 * flag. This is the preferred function to use in new code.
2206 *
2207 * Returns the container attribute or NULL on error
2208 */
2209static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
2210{
2211 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
2212}
2213
2214/**
2215 * nla_nest_end - Finalize nesting of attributes
2216 * @skb: socket buffer the attributes are stored in
2217 * @start: container attribute
2218 *
2219 * Corrects the container attribute header to include the all
2220 * appended attributes.
2221 *
2222 * Returns the total data length of the skb.
2223 */
2224static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
2225{
2226 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
2227 return skb->len;
2228}
2229
2230/**
2231 * nla_nest_cancel - Cancel nesting of attributes
2232 * @skb: socket buffer the message is stored in
2233 * @start: container attribute
2234 *
2235 * Removes the container attribute and including all nested
2236 * attributes. Returns -EMSGSIZE
2237 */
2238static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
2239{
2240 nlmsg_trim(skb, start);
2241}
2242
2243/**
2244 * __nla_validate_nested - Validate a stream of nested attributes
2245 * @start: container attribute
2246 * @maxtype: maximum attribute type to be expected
2247 * @policy: validation policy
2248 * @validate: validation strictness
2249 * @extack: extended ACK report struct
2250 *
2251 * Validates all attributes in the nested attribute stream against the
2252 * specified policy. Attributes with a type exceeding maxtype will be
2253 * ignored. See documentation of struct nla_policy for more details.
2254 *
2255 * Returns 0 on success or a negative error code.
2256 */
2257static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
2258 const struct nla_policy *policy,
2259 unsigned int validate,
2260 struct netlink_ext_ack *extack)
2261{
2262 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
2263 validate, extack);
2264}
2265
2266static inline int
2267nla_validate_nested(const struct nlattr *start, int maxtype,
2268 const struct nla_policy *policy,
2269 struct netlink_ext_ack *extack)
2270{
2271 return __nla_validate_nested(start, maxtype, policy,
2272 NL_VALIDATE_STRICT, extack);
2273}
2274
2275static inline int
2276nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
2277 const struct nla_policy *policy,
2278 struct netlink_ext_ack *extack)
2279{
2280 return __nla_validate_nested(start, maxtype, policy,
2281 NL_VALIDATE_LIBERAL, extack);
2282}
2283
2284/**
2285 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
2286 * @skb: socket buffer the message is stored in
2287 *
2288 * Return true if padding is needed to align the next attribute (nla_data()) to
2289 * a 64-bit aligned area.
2290 */
2291static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
2292{
2293#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2294 /* The nlattr header is 4 bytes in size, that's why we test
2295 * if the skb->data _is_ aligned. A NOP attribute, plus
2296 * nlattr header for next attribute, will make nla_data()
2297 * 8-byte aligned.
2298 */
2299 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
2300 return true;
2301#endif
2302 return false;
2303}
2304
2305/**
2306 * nla_align_64bit - 64-bit align the nla_data() of next attribute
2307 * @skb: socket buffer the message is stored in
2308 * @padattr: attribute type for the padding
2309 *
2310 * Conditionally emit a padding netlink attribute in order to make
2311 * the next attribute we emit have a 64-bit aligned nla_data() area.
2312 * This will only be done in architectures which do not have
2313 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
2314 *
2315 * Returns zero on success or a negative error code.
2316 */
2317static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
2318{
2319 if (nla_need_padding_for_64bit(skb) &&
2320 !nla_reserve(skb, padattr, 0))
2321 return -EMSGSIZE;
2322
2323 return 0;
2324}
2325
2326/**
2327 * nla_total_size_64bit - total length of attribute including padding
2328 * @payload: length of payload
2329 */
2330static inline int nla_total_size_64bit(int payload)
2331{
2332 return NLA_ALIGN(nla_attr_size(payload))
2333#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2334 + NLA_ALIGN(nla_attr_size(0))
2335#endif
2336 ;
2337}
2338
2339/**
2340 * nla_for_each_attr - iterate over a stream of attributes
2341 * @pos: loop counter, set to current attribute
2342 * @head: head of attribute stream
2343 * @len: length of attribute stream
2344 * @rem: initialized to len, holds bytes currently remaining in stream
2345 */
2346#define nla_for_each_attr(pos, head, len, rem) \
2347 for (pos = head, rem = len; \
2348 nla_ok(pos, rem); \
2349 pos = nla_next(pos, &(rem)))
2350
2351/**
2352 * nla_for_each_attr_type - iterate over a stream of attributes
2353 * @pos: loop counter, set to current attribute
2354 * @type: required attribute type for @pos
2355 * @head: head of attribute stream
2356 * @len: length of attribute stream
2357 * @rem: initialized to len, holds bytes currently remaining in stream
2358 */
2359#define nla_for_each_attr_type(pos, type, head, len, rem) \
2360 nla_for_each_attr(pos, head, len, rem) \
2361 if (nla_type(pos) == type)
2362
2363/**
2364 * nla_for_each_nested - iterate over nested attributes
2365 * @pos: loop counter, set to current attribute
2366 * @nla: attribute containing the nested attributes
2367 * @rem: initialized to len, holds bytes currently remaining in stream
2368 */
2369#define nla_for_each_nested(pos, nla, rem) \
2370 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
2371
2372/**
2373 * nla_for_each_nested_type - iterate over nested attributes
2374 * @pos: loop counter, set to current attribute
2375 * @type: required attribute type for @pos
2376 * @nla: attribute containing the nested attributes
2377 * @rem: initialized to len, holds bytes currently remaining in stream
2378 */
2379#define nla_for_each_nested_type(pos, type, nla, rem) \
2380 nla_for_each_nested(pos, nla, rem) \
2381 if (nla_type(pos) == type)
2382
2383/**
2384 * nla_is_last - Test if attribute is last in stream
2385 * @nla: attribute to test
2386 * @rem: bytes remaining in stream
2387 */
2388static inline bool nla_is_last(const struct nlattr *nla, int rem)
2389{
2390 return nla->nla_len == rem;
2391}
2392
2393void nla_get_range_unsigned(const struct nla_policy *pt,
2394 struct netlink_range_validation *range);
2395void nla_get_range_signed(const struct nla_policy *pt,
2396 struct netlink_range_validation_signed *range);
2397
2398struct netlink_policy_dump_state;
2399
2400int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
2401 const struct nla_policy *policy,
2402 unsigned int maxtype);
2403int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
2404 const struct nla_policy *policy,
2405 unsigned int maxtype);
2406bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
2407int netlink_policy_dump_write(struct sk_buff *skb,
2408 struct netlink_policy_dump_state *state);
2409int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
2410int netlink_policy_dump_write_attr(struct sk_buff *skb,
2411 const struct nla_policy *pt,
2412 int nestattr);
2413void netlink_policy_dump_free(struct netlink_policy_dump_state *state);
2414
2415#endif