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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_s8(skb, type, value) add s8 attribute to skb
102 * nla_put_s16(skb, type, value) add s16 attribute to skb
103 * nla_put_s32(skb, type, value) add s32 attribute to skb
104 * nla_put_s64(skb, type, value) add s64 attribute to skb
105 * nla_put_string(skb, type, str) add string attribute to skb
106 * nla_put_flag(skb, type) add flag attribute to skb
107 * nla_put_msecs(skb, type, jiffies) add msecs attribute to skb
108 *
109 * Nested Attributes Construction:
110 * nla_nest_start(skb, type) start a nested attribute
111 * nla_nest_end(skb, nla) finalize a nested attribute
112 * nla_nest_cancel(skb, nla) cancel nested attribute construction
113 *
114 * Attribute Length Calculations:
115 * nla_attr_size(payload) length of attribute w/o padding
116 * nla_total_size(payload) length of attribute w/ padding
117 * nla_padlen(payload) length of padding
118 *
119 * Attribute Payload Access:
120 * nla_data(nla) head of attribute payload
121 * nla_len(nla) length of attribute payload
122 *
123 * Attribute Payload Access for Basic Types:
124 * nla_get_u8(nla) get payload for a u8 attribute
125 * nla_get_u16(nla) get payload for a u16 attribute
126 * nla_get_u32(nla) get payload for a u32 attribute
127 * nla_get_u64(nla) get payload for a u64 attribute
128 * nla_get_s8(nla) get payload for a s8 attribute
129 * nla_get_s16(nla) get payload for a s16 attribute
130 * nla_get_s32(nla) get payload for a s32 attribute
131 * nla_get_s64(nla) get payload for a s64 attribute
132 * nla_get_flag(nla) return 1 if flag is true
133 * nla_get_msecs(nla) get payload for a msecs attribute
134 *
135 * Attribute Misc:
136 * nla_memcpy(dest, nla, count) copy attribute into memory
137 * nla_memcmp(nla, data, size) compare attribute with memory area
138 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
139 * nla_strcmp(nla, str) compare attribute with string
140 *
141 * Attribute Parsing:
142 * nla_ok(nla, remaining) does nla fit into remaining bytes?
143 * nla_next(nla, remaining) get next netlink attribute
144 * nla_validate() validate a stream of attributes
145 * nla_validate_nested() validate a stream of nested attributes
146 * nla_find() find attribute in stream of attributes
147 * nla_find_nested() find attribute in nested attributes
148 * nla_parse() parse and validate stream of attrs
149 * nla_parse_nested() parse nested attribuets
150 * nla_for_each_attr() loop over all attributes
151 * nla_for_each_nested() loop over the nested attributes
152 *=========================================================================
153 */
154
155 /**
156 * Standard attribute types to specify validation policy
157 */
158enum {
159 NLA_UNSPEC,
160 NLA_U8,
161 NLA_U16,
162 NLA_U32,
163 NLA_U64,
164 NLA_STRING,
165 NLA_FLAG,
166 NLA_MSECS,
167 NLA_NESTED,
168 NLA_NESTED_COMPAT,
169 NLA_NUL_STRING,
170 NLA_BINARY,
171 NLA_S8,
172 NLA_S16,
173 NLA_S32,
174 NLA_S64,
175 __NLA_TYPE_MAX,
176};
177
178#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
179
180/**
181 * struct nla_policy - attribute validation policy
182 * @type: Type of attribute or NLA_UNSPEC
183 * @len: Type specific length of payload
184 *
185 * Policies are defined as arrays of this struct, the array must be
186 * accessible by attribute type up to the highest identifier to be expected.
187 *
188 * Meaning of `len' field:
189 * NLA_STRING Maximum length of string
190 * NLA_NUL_STRING Maximum length of string (excluding NUL)
191 * NLA_FLAG Unused
192 * NLA_BINARY Maximum length of attribute payload
193 * NLA_NESTED Don't use `len' field -- length verification is
194 * done by checking len of nested header (or empty)
195 * NLA_NESTED_COMPAT Minimum length of structure payload
196 * NLA_U8, NLA_U16,
197 * NLA_U32, NLA_U64,
198 * NLA_S8, NLA_S16,
199 * NLA_S32, NLA_S64,
200 * NLA_MSECS Leaving the length field zero will verify the
201 * given type fits, using it verifies minimum length
202 * just like "All other"
203 * All other Minimum length of attribute payload
204 *
205 * Example:
206 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
207 * [ATTR_FOO] = { .type = NLA_U16 },
208 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
209 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
210 * };
211 */
212struct nla_policy {
213 u16 type;
214 u16 len;
215};
216
217/**
218 * struct nl_info - netlink source information
219 * @nlh: Netlink message header of original request
220 * @portid: Netlink PORTID of requesting application
221 */
222struct nl_info {
223 struct nlmsghdr *nlh;
224 struct net *nl_net;
225 u32 portid;
226};
227
228int netlink_rcv_skb(struct sk_buff *skb,
229 int (*cb)(struct sk_buff *, struct nlmsghdr *));
230int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
231 unsigned int group, int report, gfp_t flags);
232
233int nla_validate(const struct nlattr *head, int len, int maxtype,
234 const struct nla_policy *policy);
235int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
236 int len, const struct nla_policy *policy);
237int nla_policy_len(const struct nla_policy *, int);
238struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
239size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
240int nla_memcpy(void *dest, const struct nlattr *src, int count);
241int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
242int nla_strcmp(const struct nlattr *nla, const char *str);
243struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
244void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
245struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
246void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
247void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
248 const void *data);
249void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
250int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
251int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
252int nla_append(struct sk_buff *skb, int attrlen, const void *data);
253
254/**************************************************************************
255 * Netlink Messages
256 **************************************************************************/
257
258/**
259 * nlmsg_msg_size - length of netlink message not including padding
260 * @payload: length of message payload
261 */
262static inline int nlmsg_msg_size(int payload)
263{
264 return NLMSG_HDRLEN + payload;
265}
266
267/**
268 * nlmsg_total_size - length of netlink message including padding
269 * @payload: length of message payload
270 */
271static inline int nlmsg_total_size(int payload)
272{
273 return NLMSG_ALIGN(nlmsg_msg_size(payload));
274}
275
276/**
277 * nlmsg_padlen - length of padding at the message's tail
278 * @payload: length of message payload
279 */
280static inline int nlmsg_padlen(int payload)
281{
282 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
283}
284
285/**
286 * nlmsg_data - head of message payload
287 * @nlh: netlink message header
288 */
289static inline void *nlmsg_data(const struct nlmsghdr *nlh)
290{
291 return (unsigned char *) nlh + NLMSG_HDRLEN;
292}
293
294/**
295 * nlmsg_len - length of message payload
296 * @nlh: netlink message header
297 */
298static inline int nlmsg_len(const struct nlmsghdr *nlh)
299{
300 return nlh->nlmsg_len - NLMSG_HDRLEN;
301}
302
303/**
304 * nlmsg_attrdata - head of attributes data
305 * @nlh: netlink message header
306 * @hdrlen: length of family specific header
307 */
308static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
309 int hdrlen)
310{
311 unsigned char *data = nlmsg_data(nlh);
312 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
313}
314
315/**
316 * nlmsg_attrlen - length of attributes data
317 * @nlh: netlink message header
318 * @hdrlen: length of family specific header
319 */
320static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
321{
322 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
323}
324
325/**
326 * nlmsg_ok - check if the netlink message fits into the remaining bytes
327 * @nlh: netlink message header
328 * @remaining: number of bytes remaining in message stream
329 */
330static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
331{
332 return (remaining >= (int) sizeof(struct nlmsghdr) &&
333 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
334 nlh->nlmsg_len <= remaining);
335}
336
337/**
338 * nlmsg_next - next netlink message in message stream
339 * @nlh: netlink message header
340 * @remaining: number of bytes remaining in message stream
341 *
342 * Returns the next netlink message in the message stream and
343 * decrements remaining by the size of the current message.
344 */
345static inline struct nlmsghdr *
346nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
347{
348 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
349
350 *remaining -= totlen;
351
352 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
353}
354
355/**
356 * nlmsg_parse - parse attributes of a netlink message
357 * @nlh: netlink message header
358 * @hdrlen: length of family specific header
359 * @tb: destination array with maxtype+1 elements
360 * @maxtype: maximum attribute type to be expected
361 * @policy: validation policy
362 *
363 * See nla_parse()
364 */
365static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
366 struct nlattr *tb[], int maxtype,
367 const struct nla_policy *policy)
368{
369 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
370 return -EINVAL;
371
372 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
373 nlmsg_attrlen(nlh, hdrlen), policy);
374}
375
376/**
377 * nlmsg_find_attr - find a specific attribute in a netlink message
378 * @nlh: netlink message header
379 * @hdrlen: length of familiy specific header
380 * @attrtype: type of attribute to look for
381 *
382 * Returns the first attribute which matches the specified type.
383 */
384static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
385 int hdrlen, int attrtype)
386{
387 return nla_find(nlmsg_attrdata(nlh, hdrlen),
388 nlmsg_attrlen(nlh, hdrlen), attrtype);
389}
390
391/**
392 * nlmsg_validate - validate a netlink message including attributes
393 * @nlh: netlinket message header
394 * @hdrlen: length of familiy specific header
395 * @maxtype: maximum attribute type to be expected
396 * @policy: validation policy
397 */
398static inline int nlmsg_validate(const struct nlmsghdr *nlh,
399 int hdrlen, int maxtype,
400 const struct nla_policy *policy)
401{
402 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
403 return -EINVAL;
404
405 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
406 nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
407}
408
409/**
410 * nlmsg_report - need to report back to application?
411 * @nlh: netlink message header
412 *
413 * Returns 1 if a report back to the application is requested.
414 */
415static inline int nlmsg_report(const struct nlmsghdr *nlh)
416{
417 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
418}
419
420/**
421 * nlmsg_for_each_attr - iterate over a stream of attributes
422 * @pos: loop counter, set to current attribute
423 * @nlh: netlink message header
424 * @hdrlen: length of familiy specific header
425 * @rem: initialized to len, holds bytes currently remaining in stream
426 */
427#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
428 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
429 nlmsg_attrlen(nlh, hdrlen), rem)
430
431/**
432 * nlmsg_put - Add a new netlink message to an skb
433 * @skb: socket buffer to store message in
434 * @portid: netlink process id
435 * @seq: sequence number of message
436 * @type: message type
437 * @payload: length of message payload
438 * @flags: message flags
439 *
440 * Returns NULL if the tailroom of the skb is insufficient to store
441 * the message header and payload.
442 */
443static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
444 int type, int payload, int flags)
445{
446 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
447 return NULL;
448
449 return __nlmsg_put(skb, portid, seq, type, payload, flags);
450}
451
452/**
453 * nlmsg_put_answer - Add a new callback based netlink message to an skb
454 * @skb: socket buffer to store message in
455 * @cb: netlink callback
456 * @type: message type
457 * @payload: length of message payload
458 * @flags: message flags
459 *
460 * Returns NULL if the tailroom of the skb is insufficient to store
461 * the message header and payload.
462 */
463static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
464 struct netlink_callback *cb,
465 int type, int payload,
466 int flags)
467{
468 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
469 type, payload, flags);
470}
471
472/**
473 * nlmsg_new - Allocate a new netlink message
474 * @payload: size of the message payload
475 * @flags: the type of memory to allocate.
476 *
477 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
478 * and a good default is needed.
479 */
480static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
481{
482 return alloc_skb(nlmsg_total_size(payload), flags);
483}
484
485/**
486 * nlmsg_end - Finalize a netlink message
487 * @skb: socket buffer the message is stored in
488 * @nlh: netlink message header
489 *
490 * Corrects the netlink message header to include the appeneded
491 * attributes. Only necessary if attributes have been added to
492 * the message.
493 *
494 * Returns the total data length of the skb.
495 */
496static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
497{
498 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
499
500 return skb->len;
501}
502
503/**
504 * nlmsg_get_pos - return current position in netlink message
505 * @skb: socket buffer the message is stored in
506 *
507 * Returns a pointer to the current tail of the message.
508 */
509static inline void *nlmsg_get_pos(struct sk_buff *skb)
510{
511 return skb_tail_pointer(skb);
512}
513
514/**
515 * nlmsg_trim - Trim message to a mark
516 * @skb: socket buffer the message is stored in
517 * @mark: mark to trim to
518 *
519 * Trims the message to the provided mark.
520 */
521static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
522{
523 if (mark)
524 skb_trim(skb, (unsigned char *) mark - skb->data);
525}
526
527/**
528 * nlmsg_cancel - Cancel construction of a netlink message
529 * @skb: socket buffer the message is stored in
530 * @nlh: netlink message header
531 *
532 * Removes the complete netlink message including all
533 * attributes from the socket buffer again.
534 */
535static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
536{
537 nlmsg_trim(skb, nlh);
538}
539
540/**
541 * nlmsg_free - free a netlink message
542 * @skb: socket buffer of netlink message
543 */
544static inline void nlmsg_free(struct sk_buff *skb)
545{
546 kfree_skb(skb);
547}
548
549/**
550 * nlmsg_multicast - multicast a netlink message
551 * @sk: netlink socket to spread messages to
552 * @skb: netlink message as socket buffer
553 * @portid: own netlink portid to avoid sending to yourself
554 * @group: multicast group id
555 * @flags: allocation flags
556 */
557static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
558 u32 portid, unsigned int group, gfp_t flags)
559{
560 int err;
561
562 NETLINK_CB(skb).dst_group = group;
563
564 err = netlink_broadcast(sk, skb, portid, group, flags);
565 if (err > 0)
566 err = 0;
567
568 return err;
569}
570
571/**
572 * nlmsg_unicast - unicast a netlink message
573 * @sk: netlink socket to spread message to
574 * @skb: netlink message as socket buffer
575 * @portid: netlink portid of the destination socket
576 */
577static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
578{
579 int err;
580
581 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
582 if (err > 0)
583 err = 0;
584
585 return err;
586}
587
588/**
589 * nlmsg_for_each_msg - iterate over a stream of messages
590 * @pos: loop counter, set to current message
591 * @head: head of message stream
592 * @len: length of message stream
593 * @rem: initialized to len, holds bytes currently remaining in stream
594 */
595#define nlmsg_for_each_msg(pos, head, len, rem) \
596 for (pos = head, rem = len; \
597 nlmsg_ok(pos, rem); \
598 pos = nlmsg_next(pos, &(rem)))
599
600/**
601 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
602 * @cb: netlink callback structure that stores the sequence number
603 * @nlh: netlink message header to write the flag to
604 *
605 * This function checks if the sequence (generation) number changed during dump
606 * and if it did, advertises it in the netlink message header.
607 *
608 * The correct way to use it is to set cb->seq to the generation counter when
609 * all locks for dumping have been acquired, and then call this function for
610 * each message that is generated.
611 *
612 * Note that due to initialisation concerns, 0 is an invalid sequence number
613 * and must not be used by code that uses this functionality.
614 */
615static inline void
616nl_dump_check_consistent(struct netlink_callback *cb,
617 struct nlmsghdr *nlh)
618{
619 if (cb->prev_seq && cb->seq != cb->prev_seq)
620 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
621 cb->prev_seq = cb->seq;
622}
623
624/**************************************************************************
625 * Netlink Attributes
626 **************************************************************************/
627
628/**
629 * nla_attr_size - length of attribute not including padding
630 * @payload: length of payload
631 */
632static inline int nla_attr_size(int payload)
633{
634 return NLA_HDRLEN + payload;
635}
636
637/**
638 * nla_total_size - total length of attribute including padding
639 * @payload: length of payload
640 */
641static inline int nla_total_size(int payload)
642{
643 return NLA_ALIGN(nla_attr_size(payload));
644}
645
646/**
647 * nla_padlen - length of padding at the tail of attribute
648 * @payload: length of payload
649 */
650static inline int nla_padlen(int payload)
651{
652 return nla_total_size(payload) - nla_attr_size(payload);
653}
654
655/**
656 * nla_type - attribute type
657 * @nla: netlink attribute
658 */
659static inline int nla_type(const struct nlattr *nla)
660{
661 return nla->nla_type & NLA_TYPE_MASK;
662}
663
664/**
665 * nla_data - head of payload
666 * @nla: netlink attribute
667 */
668static inline void *nla_data(const struct nlattr *nla)
669{
670 return (char *) nla + NLA_HDRLEN;
671}
672
673/**
674 * nla_len - length of payload
675 * @nla: netlink attribute
676 */
677static inline int nla_len(const struct nlattr *nla)
678{
679 return nla->nla_len - NLA_HDRLEN;
680}
681
682/**
683 * nla_ok - check if the netlink attribute fits into the remaining bytes
684 * @nla: netlink attribute
685 * @remaining: number of bytes remaining in attribute stream
686 */
687static inline int nla_ok(const struct nlattr *nla, int remaining)
688{
689 return remaining >= (int) sizeof(*nla) &&
690 nla->nla_len >= sizeof(*nla) &&
691 nla->nla_len <= remaining;
692}
693
694/**
695 * nla_next - next netlink attribute in attribute stream
696 * @nla: netlink attribute
697 * @remaining: number of bytes remaining in attribute stream
698 *
699 * Returns the next netlink attribute in the attribute stream and
700 * decrements remaining by the size of the current attribute.
701 */
702static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
703{
704 int totlen = NLA_ALIGN(nla->nla_len);
705
706 *remaining -= totlen;
707 return (struct nlattr *) ((char *) nla + totlen);
708}
709
710/**
711 * nla_find_nested - find attribute in a set of nested attributes
712 * @nla: attribute containing the nested attributes
713 * @attrtype: type of attribute to look for
714 *
715 * Returns the first attribute which matches the specified type.
716 */
717static inline struct nlattr *
718nla_find_nested(const struct nlattr *nla, int attrtype)
719{
720 return nla_find(nla_data(nla), nla_len(nla), attrtype);
721}
722
723/**
724 * nla_parse_nested - parse nested attributes
725 * @tb: destination array with maxtype+1 elements
726 * @maxtype: maximum attribute type to be expected
727 * @nla: attribute containing the nested attributes
728 * @policy: validation policy
729 *
730 * See nla_parse()
731 */
732static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
733 const struct nlattr *nla,
734 const struct nla_policy *policy)
735{
736 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
737}
738
739/**
740 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
741 * @skb: socket buffer to add attribute to
742 * @attrtype: attribute type
743 * @value: numeric value
744 */
745static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
746{
747 return nla_put(skb, attrtype, sizeof(u8), &value);
748}
749
750/**
751 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
752 * @skb: socket buffer to add attribute to
753 * @attrtype: attribute type
754 * @value: numeric value
755 */
756static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
757{
758 return nla_put(skb, attrtype, sizeof(u16), &value);
759}
760
761/**
762 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
763 * @skb: socket buffer to add attribute to
764 * @attrtype: attribute type
765 * @value: numeric value
766 */
767static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
768{
769 return nla_put(skb, attrtype, sizeof(__be16), &value);
770}
771
772/**
773 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
774 * @skb: socket buffer to add attribute to
775 * @attrtype: attribute type
776 * @value: numeric value
777 */
778static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
779{
780 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, value);
781}
782
783/**
784 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
785 * @skb: socket buffer to add attribute to
786 * @attrtype: attribute type
787 * @value: numeric value
788 */
789static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
790{
791 return nla_put(skb, attrtype, sizeof(__le16), &value);
792}
793
794/**
795 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
796 * @skb: socket buffer to add attribute to
797 * @attrtype: attribute type
798 * @value: numeric value
799 */
800static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
801{
802 return nla_put(skb, attrtype, sizeof(u32), &value);
803}
804
805/**
806 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
807 * @skb: socket buffer to add attribute to
808 * @attrtype: attribute type
809 * @value: numeric value
810 */
811static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
812{
813 return nla_put(skb, attrtype, sizeof(__be32), &value);
814}
815
816/**
817 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
818 * @skb: socket buffer to add attribute to
819 * @attrtype: attribute type
820 * @value: numeric value
821 */
822static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
823{
824 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, value);
825}
826
827/**
828 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
829 * @skb: socket buffer to add attribute to
830 * @attrtype: attribute type
831 * @value: numeric value
832 */
833static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
834{
835 return nla_put(skb, attrtype, sizeof(__le32), &value);
836}
837
838/**
839 * nla_put_u64 - Add a u64 netlink attribute to a socket buffer
840 * @skb: socket buffer to add attribute to
841 * @attrtype: attribute type
842 * @value: numeric value
843 */
844static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
845{
846 return nla_put(skb, attrtype, sizeof(u64), &value);
847}
848
849/**
850 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer
851 * @skb: socket buffer to add attribute to
852 * @attrtype: attribute type
853 * @value: numeric value
854 */
855static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value)
856{
857 return nla_put(skb, attrtype, sizeof(__be64), &value);
858}
859
860/**
861 * nla_put_net64 - Add 64-bit network byte order netlink attribute to a socket buffer
862 * @skb: socket buffer to add attribute to
863 * @attrtype: attribute type
864 * @value: numeric value
865 */
866static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value)
867{
868 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, value);
869}
870
871/**
872 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer
873 * @skb: socket buffer to add attribute to
874 * @attrtype: attribute type
875 * @value: numeric value
876 */
877static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value)
878{
879 return nla_put(skb, attrtype, sizeof(__le64), &value);
880}
881
882/**
883 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
884 * @skb: socket buffer to add attribute to
885 * @attrtype: attribute type
886 * @value: numeric value
887 */
888static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
889{
890 return nla_put(skb, attrtype, sizeof(s8), &value);
891}
892
893/**
894 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
895 * @skb: socket buffer to add attribute to
896 * @attrtype: attribute type
897 * @value: numeric value
898 */
899static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
900{
901 return nla_put(skb, attrtype, sizeof(s16), &value);
902}
903
904/**
905 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
906 * @skb: socket buffer to add attribute to
907 * @attrtype: attribute type
908 * @value: numeric value
909 */
910static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
911{
912 return nla_put(skb, attrtype, sizeof(s32), &value);
913}
914
915/**
916 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer
917 * @skb: socket buffer to add attribute to
918 * @attrtype: attribute type
919 * @value: numeric value
920 */
921static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value)
922{
923 return nla_put(skb, attrtype, sizeof(s64), &value);
924}
925
926/**
927 * nla_put_string - Add a string netlink attribute to a socket buffer
928 * @skb: socket buffer to add attribute to
929 * @attrtype: attribute type
930 * @str: NUL terminated string
931 */
932static inline int nla_put_string(struct sk_buff *skb, int attrtype,
933 const char *str)
934{
935 return nla_put(skb, attrtype, strlen(str) + 1, str);
936}
937
938/**
939 * nla_put_flag - Add a flag netlink attribute to a socket buffer
940 * @skb: socket buffer to add attribute to
941 * @attrtype: attribute type
942 */
943static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
944{
945 return nla_put(skb, attrtype, 0, NULL);
946}
947
948/**
949 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer
950 * @skb: socket buffer to add attribute to
951 * @attrtype: attribute type
952 * @jiffies: number of msecs in jiffies
953 */
954static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
955 unsigned long jiffies)
956{
957 u64 tmp = jiffies_to_msecs(jiffies);
958 return nla_put(skb, attrtype, sizeof(u64), &tmp);
959}
960
961/**
962 * nla_get_u32 - return payload of u32 attribute
963 * @nla: u32 netlink attribute
964 */
965static inline u32 nla_get_u32(const struct nlattr *nla)
966{
967 return *(u32 *) nla_data(nla);
968}
969
970/**
971 * nla_get_be32 - return payload of __be32 attribute
972 * @nla: __be32 netlink attribute
973 */
974static inline __be32 nla_get_be32(const struct nlattr *nla)
975{
976 return *(__be32 *) nla_data(nla);
977}
978
979/**
980 * nla_get_u16 - return payload of u16 attribute
981 * @nla: u16 netlink attribute
982 */
983static inline u16 nla_get_u16(const struct nlattr *nla)
984{
985 return *(u16 *) nla_data(nla);
986}
987
988/**
989 * nla_get_be16 - return payload of __be16 attribute
990 * @nla: __be16 netlink attribute
991 */
992static inline __be16 nla_get_be16(const struct nlattr *nla)
993{
994 return *(__be16 *) nla_data(nla);
995}
996
997/**
998 * nla_get_le16 - return payload of __le16 attribute
999 * @nla: __le16 netlink attribute
1000 */
1001static inline __le16 nla_get_le16(const struct nlattr *nla)
1002{
1003 return *(__le16 *) nla_data(nla);
1004}
1005
1006/**
1007 * nla_get_u8 - return payload of u8 attribute
1008 * @nla: u8 netlink attribute
1009 */
1010static inline u8 nla_get_u8(const struct nlattr *nla)
1011{
1012 return *(u8 *) nla_data(nla);
1013}
1014
1015/**
1016 * nla_get_u64 - return payload of u64 attribute
1017 * @nla: u64 netlink attribute
1018 */
1019static inline u64 nla_get_u64(const struct nlattr *nla)
1020{
1021 u64 tmp;
1022
1023 nla_memcpy(&tmp, nla, sizeof(tmp));
1024
1025 return tmp;
1026}
1027
1028/**
1029 * nla_get_be64 - return payload of __be64 attribute
1030 * @nla: __be64 netlink attribute
1031 */
1032static inline __be64 nla_get_be64(const struct nlattr *nla)
1033{
1034 __be64 tmp;
1035
1036 nla_memcpy(&tmp, nla, sizeof(tmp));
1037
1038 return tmp;
1039}
1040
1041/**
1042 * nla_get_s32 - return payload of s32 attribute
1043 * @nla: s32 netlink attribute
1044 */
1045static inline s32 nla_get_s32(const struct nlattr *nla)
1046{
1047 return *(s32 *) nla_data(nla);
1048}
1049
1050/**
1051 * nla_get_s16 - return payload of s16 attribute
1052 * @nla: s16 netlink attribute
1053 */
1054static inline s16 nla_get_s16(const struct nlattr *nla)
1055{
1056 return *(s16 *) nla_data(nla);
1057}
1058
1059/**
1060 * nla_get_s8 - return payload of s8 attribute
1061 * @nla: s8 netlink attribute
1062 */
1063static inline s8 nla_get_s8(const struct nlattr *nla)
1064{
1065 return *(s8 *) nla_data(nla);
1066}
1067
1068/**
1069 * nla_get_s64 - return payload of s64 attribute
1070 * @nla: s64 netlink attribute
1071 */
1072static inline s64 nla_get_s64(const struct nlattr *nla)
1073{
1074 s64 tmp;
1075
1076 nla_memcpy(&tmp, nla, sizeof(tmp));
1077
1078 return tmp;
1079}
1080
1081/**
1082 * nla_get_flag - return payload of flag attribute
1083 * @nla: flag netlink attribute
1084 */
1085static inline int nla_get_flag(const struct nlattr *nla)
1086{
1087 return !!nla;
1088}
1089
1090/**
1091 * nla_get_msecs - return payload of msecs attribute
1092 * @nla: msecs netlink attribute
1093 *
1094 * Returns the number of milliseconds in jiffies.
1095 */
1096static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1097{
1098 u64 msecs = nla_get_u64(nla);
1099
1100 return msecs_to_jiffies((unsigned long) msecs);
1101}
1102
1103/**
1104 * nla_nest_start - Start a new level of nested attributes
1105 * @skb: socket buffer to add attributes to
1106 * @attrtype: attribute type of container
1107 *
1108 * Returns the container attribute
1109 */
1110static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1111{
1112 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1113
1114 if (nla_put(skb, attrtype, 0, NULL) < 0)
1115 return NULL;
1116
1117 return start;
1118}
1119
1120/**
1121 * nla_nest_end - Finalize nesting of attributes
1122 * @skb: socket buffer the attributes are stored in
1123 * @start: container attribute
1124 *
1125 * Corrects the container attribute header to include the all
1126 * appeneded attributes.
1127 *
1128 * Returns the total data length of the skb.
1129 */
1130static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1131{
1132 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1133 return skb->len;
1134}
1135
1136/**
1137 * nla_nest_cancel - Cancel nesting of attributes
1138 * @skb: socket buffer the message is stored in
1139 * @start: container attribute
1140 *
1141 * Removes the container attribute and including all nested
1142 * attributes. Returns -EMSGSIZE
1143 */
1144static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1145{
1146 nlmsg_trim(skb, start);
1147}
1148
1149/**
1150 * nla_validate_nested - Validate a stream of nested attributes
1151 * @start: container attribute
1152 * @maxtype: maximum attribute type to be expected
1153 * @policy: validation policy
1154 *
1155 * Validates all attributes in the nested attribute stream against the
1156 * specified policy. Attributes with a type exceeding maxtype will be
1157 * ignored. See documenation of struct nla_policy for more details.
1158 *
1159 * Returns 0 on success or a negative error code.
1160 */
1161static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
1162 const struct nla_policy *policy)
1163{
1164 return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
1165}
1166
1167/**
1168 * nla_for_each_attr - iterate over a stream of attributes
1169 * @pos: loop counter, set to current attribute
1170 * @head: head of attribute stream
1171 * @len: length of attribute stream
1172 * @rem: initialized to len, holds bytes currently remaining in stream
1173 */
1174#define nla_for_each_attr(pos, head, len, rem) \
1175 for (pos = head, rem = len; \
1176 nla_ok(pos, rem); \
1177 pos = nla_next(pos, &(rem)))
1178
1179/**
1180 * nla_for_each_nested - iterate over nested attributes
1181 * @pos: loop counter, set to current attribute
1182 * @nla: attribute containing the nested attributes
1183 * @rem: initialized to len, holds bytes currently remaining in stream
1184 */
1185#define nla_for_each_nested(pos, nla, rem) \
1186 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1187
1188#endif
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __NET_NETLINK_H
3#define __NET_NETLINK_H
4
5#include <linux/types.h>
6#include <linux/netlink.h>
7#include <linux/jiffies.h>
8#include <linux/in6.h>
9
10/* ========================================================================
11 * Netlink Messages and Attributes Interface (As Seen On TV)
12 * ------------------------------------------------------------------------
13 * Messages Interface
14 * ------------------------------------------------------------------------
15 *
16 * Message Format:
17 * <--- nlmsg_total_size(payload) --->
18 * <-- nlmsg_msg_size(payload) ->
19 * +----------+- - -+-------------+- - -+-------- - -
20 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr
21 * +----------+- - -+-------------+- - -+-------- - -
22 * nlmsg_data(nlh)---^ ^
23 * nlmsg_next(nlh)-----------------------+
24 *
25 * Payload Format:
26 * <---------------------- nlmsg_len(nlh) --------------------->
27 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
28 * +----------------------+- - -+--------------------------------+
29 * | Family Header | Pad | Attributes |
30 * +----------------------+- - -+--------------------------------+
31 * nlmsg_attrdata(nlh, hdrlen)---^
32 *
33 * Data Structures:
34 * struct nlmsghdr netlink message header
35 *
36 * Message Construction:
37 * nlmsg_new() create a new netlink message
38 * nlmsg_put() add a netlink message to an skb
39 * nlmsg_put_answer() callback based nlmsg_put()
40 * nlmsg_end() finalize netlink message
41 * nlmsg_get_pos() return current position in message
42 * nlmsg_trim() trim part of message
43 * nlmsg_cancel() cancel message construction
44 * nlmsg_free() free a netlink message
45 *
46 * Message Sending:
47 * nlmsg_multicast() multicast message to several groups
48 * nlmsg_unicast() unicast a message to a single socket
49 * nlmsg_notify() send notification message
50 *
51 * Message Length Calculations:
52 * nlmsg_msg_size(payload) length of message w/o padding
53 * nlmsg_total_size(payload) length of message w/ padding
54 * nlmsg_padlen(payload) length of padding at tail
55 *
56 * Message Payload Access:
57 * nlmsg_data(nlh) head of message payload
58 * nlmsg_len(nlh) length of message payload
59 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
60 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
61 *
62 * Message Parsing:
63 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
64 * nlmsg_next(nlh, remaining) get next netlink message
65 * nlmsg_parse() parse attributes of a message
66 * nlmsg_find_attr() find an attribute in a message
67 * nlmsg_for_each_msg() loop over all messages
68 * nlmsg_validate() validate netlink message incl. attrs
69 * nlmsg_for_each_attr() loop over all attributes
70 *
71 * Misc:
72 * nlmsg_report() report back to application?
73 *
74 * ------------------------------------------------------------------------
75 * Attributes Interface
76 * ------------------------------------------------------------------------
77 *
78 * Attribute Format:
79 * <------- nla_total_size(payload) ------->
80 * <---- nla_attr_size(payload) ----->
81 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
82 * | Header | Pad | Payload | Pad | Header
83 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
84 * <- nla_len(nla) -> ^
85 * nla_data(nla)----^ |
86 * nla_next(nla)-----------------------------'
87 *
88 * Data Structures:
89 * struct nlattr netlink attribute header
90 *
91 * Attribute Construction:
92 * nla_reserve(skb, type, len) reserve room for an attribute
93 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
94 * nla_put(skb, type, len, data) add attribute to skb
95 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
96 * nla_append(skb, len, data) append data to skb
97 *
98 * Attribute Construction for Basic Types:
99 * nla_put_u8(skb, type, value) add u8 attribute to skb
100 * nla_put_u16(skb, type, value) add u16 attribute to skb
101 * nla_put_u32(skb, type, value) add u32 attribute to skb
102 * nla_put_u64_64bit(skb, type,
103 * value, padattr) add u64 attribute to skb
104 * nla_put_s8(skb, type, value) add s8 attribute to skb
105 * nla_put_s16(skb, type, value) add s16 attribute to skb
106 * nla_put_s32(skb, type, value) add s32 attribute to skb
107 * nla_put_s64(skb, type, value,
108 * padattr) add s64 attribute to skb
109 * nla_put_string(skb, type, str) add string attribute to skb
110 * nla_put_flag(skb, type) add flag attribute to skb
111 * nla_put_msecs(skb, type, jiffies,
112 * padattr) add msecs attribute to skb
113 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb
114 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb
115 *
116 * Nested Attributes Construction:
117 * nla_nest_start(skb, type) start a nested attribute
118 * nla_nest_end(skb, nla) finalize a nested attribute
119 * nla_nest_cancel(skb, nla) cancel nested attribute construction
120 *
121 * Attribute Length Calculations:
122 * nla_attr_size(payload) length of attribute w/o padding
123 * nla_total_size(payload) length of attribute w/ padding
124 * nla_padlen(payload) length of padding
125 *
126 * Attribute Payload Access:
127 * nla_data(nla) head of attribute payload
128 * nla_len(nla) length of attribute payload
129 *
130 * Attribute Payload Access for Basic Types:
131 * nla_get_uint(nla) get payload for a uint attribute
132 * nla_get_sint(nla) get payload for a sint attribute
133 * nla_get_u8(nla) get payload for a u8 attribute
134 * nla_get_u16(nla) get payload for a u16 attribute
135 * nla_get_u32(nla) get payload for a u32 attribute
136 * nla_get_u64(nla) get payload for a u64 attribute
137 * nla_get_s8(nla) get payload for a s8 attribute
138 * nla_get_s16(nla) get payload for a s16 attribute
139 * nla_get_s32(nla) get payload for a s32 attribute
140 * nla_get_s64(nla) get payload for a s64 attribute
141 * nla_get_flag(nla) return 1 if flag is true
142 * nla_get_msecs(nla) get payload for a msecs attribute
143 *
144 * Attribute Misc:
145 * nla_memcpy(dest, nla, count) copy attribute into memory
146 * nla_memcmp(nla, data, size) compare attribute with memory area
147 * nla_strscpy(dst, nla, size) copy attribute to a sized string
148 * nla_strcmp(nla, str) compare attribute with string
149 *
150 * Attribute Parsing:
151 * nla_ok(nla, remaining) does nla fit into remaining bytes?
152 * nla_next(nla, remaining) get next netlink attribute
153 * nla_validate() validate a stream of attributes
154 * nla_validate_nested() validate a stream of nested attributes
155 * nla_find() find attribute in stream of attributes
156 * nla_find_nested() find attribute in nested attributes
157 * nla_parse() parse and validate stream of attrs
158 * nla_parse_nested() parse nested attributes
159 * nla_for_each_attr() loop over all attributes
160 * nla_for_each_nested() loop over the nested attributes
161 *=========================================================================
162 */
163
164 /**
165 * Standard attribute types to specify validation policy
166 */
167enum {
168 NLA_UNSPEC,
169 NLA_U8,
170 NLA_U16,
171 NLA_U32,
172 NLA_U64,
173 NLA_STRING,
174 NLA_FLAG,
175 NLA_MSECS,
176 NLA_NESTED,
177 NLA_NESTED_ARRAY,
178 NLA_NUL_STRING,
179 NLA_BINARY,
180 NLA_S8,
181 NLA_S16,
182 NLA_S32,
183 NLA_S64,
184 NLA_BITFIELD32,
185 NLA_REJECT,
186 NLA_BE16,
187 NLA_BE32,
188 NLA_SINT,
189 NLA_UINT,
190 __NLA_TYPE_MAX,
191};
192
193#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
194
195struct netlink_range_validation {
196 u64 min, max;
197};
198
199struct netlink_range_validation_signed {
200 s64 min, max;
201};
202
203enum nla_policy_validation {
204 NLA_VALIDATE_NONE,
205 NLA_VALIDATE_RANGE,
206 NLA_VALIDATE_RANGE_WARN_TOO_LONG,
207 NLA_VALIDATE_MIN,
208 NLA_VALIDATE_MAX,
209 NLA_VALIDATE_MASK,
210 NLA_VALIDATE_RANGE_PTR,
211 NLA_VALIDATE_FUNCTION,
212};
213
214/**
215 * struct nla_policy - attribute validation policy
216 * @type: Type of attribute or NLA_UNSPEC
217 * @validation_type: type of attribute validation done in addition to
218 * type-specific validation (e.g. range, function call), see
219 * &enum nla_policy_validation
220 * @len: Type specific length of payload
221 *
222 * Policies are defined as arrays of this struct, the array must be
223 * accessible by attribute type up to the highest identifier to be expected.
224 *
225 * Meaning of `len' field:
226 * NLA_STRING Maximum length of string
227 * NLA_NUL_STRING Maximum length of string (excluding NUL)
228 * NLA_FLAG Unused
229 * NLA_BINARY Maximum length of attribute payload
230 * (but see also below with the validation type)
231 * NLA_NESTED,
232 * NLA_NESTED_ARRAY Length verification is done by checking len of
233 * nested header (or empty); len field is used if
234 * nested_policy is also used, for the max attr
235 * number in the nested policy.
236 * NLA_SINT, NLA_UINT,
237 * NLA_U8, NLA_U16,
238 * NLA_U32, NLA_U64,
239 * NLA_S8, NLA_S16,
240 * NLA_S32, NLA_S64,
241 * NLA_BE16, NLA_BE32,
242 * NLA_MSECS Leaving the length field zero will verify the
243 * given type fits, using it verifies minimum length
244 * just like "All other"
245 * NLA_BITFIELD32 Unused
246 * NLA_REJECT Unused
247 * All other Minimum length of attribute payload
248 *
249 * Meaning of validation union:
250 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and
251 * `bitfield32_valid' is the u32 value of valid flags
252 * NLA_REJECT This attribute is always rejected and `reject_message'
253 * may point to a string to report as the error instead
254 * of the generic one in extended ACK.
255 * NLA_NESTED `nested_policy' to a nested policy to validate, must
256 * also set `len' to the max attribute number. Use the
257 * provided NLA_POLICY_NESTED() macro.
258 * Note that nla_parse() will validate, but of course not
259 * parse, the nested sub-policies.
260 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate,
261 * must also set `len' to the max attribute number. Use
262 * the provided NLA_POLICY_NESTED_ARRAY() macro.
263 * The difference to NLA_NESTED is the structure:
264 * NLA_NESTED has the nested attributes directly inside
265 * while an array has the nested attributes at another
266 * level down and the attribute types directly in the
267 * nesting don't matter.
268 * NLA_UINT,
269 * NLA_U8,
270 * NLA_U16,
271 * NLA_U32,
272 * NLA_U64,
273 * NLA_BE16,
274 * NLA_BE32,
275 * NLA_SINT,
276 * NLA_S8,
277 * NLA_S16,
278 * NLA_S32,
279 * NLA_S64 The `min' and `max' fields are used depending on the
280 * validation_type field, if that is min/max/range then
281 * the min, max or both are used (respectively) to check
282 * the value of the integer attribute.
283 * Note that in the interest of code simplicity and
284 * struct size both limits are s16, so you cannot
285 * enforce a range that doesn't fall within the range
286 * of s16 - do that using the NLA_POLICY_FULL_RANGE()
287 * or NLA_POLICY_FULL_RANGE_SIGNED() macros instead.
288 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
289 * NLA_POLICY_RANGE() macros.
290 * NLA_UINT,
291 * NLA_U8,
292 * NLA_U16,
293 * NLA_U32,
294 * NLA_U64 If the validation_type field instead is set to
295 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
296 * to a struct netlink_range_validation that indicates
297 * the min/max values.
298 * Use NLA_POLICY_FULL_RANGE().
299 * NLA_SINT,
300 * NLA_S8,
301 * NLA_S16,
302 * NLA_S32,
303 * NLA_S64 If the validation_type field instead is set to
304 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
305 * pointer to a struct netlink_range_validation_signed
306 * that indicates the min/max values.
307 * Use NLA_POLICY_FULL_RANGE_SIGNED().
308 *
309 * NLA_BINARY If the validation type is like the ones for integers
310 * above, then the min/max length (not value like for
311 * integers) of the attribute is enforced.
312 *
313 * All other Unused - but note that it's a union
314 *
315 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
316 * NLA_BINARY Validation function called for the attribute.
317 * All other Unused - but note that it's a union
318 *
319 * Example:
320 *
321 * static const u32 myvalidflags = 0xff231023;
322 *
323 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
324 * [ATTR_FOO] = { .type = NLA_U16 },
325 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
326 * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)),
327 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
328 * };
329 */
330struct nla_policy {
331 u8 type;
332 u8 validation_type;
333 u16 len;
334 union {
335 /**
336 * @strict_start_type: first attribute to validate strictly
337 *
338 * This entry is special, and used for the attribute at index 0
339 * only, and specifies special data about the policy, namely it
340 * specifies the "boundary type" where strict length validation
341 * starts for any attribute types >= this value, also, strict
342 * nesting validation starts here.
343 *
344 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
345 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to
346 * get the previous pure { .len = xyz } behaviour. The advantage
347 * of this is that types not specified in the policy will be
348 * rejected.
349 *
350 * For completely new families it should be set to 1 so that the
351 * validation is enforced for all attributes. For existing ones
352 * it should be set at least when new attributes are added to
353 * the enum used by the policy, and be set to the new value that
354 * was added to enforce strict validation from thereon.
355 */
356 u16 strict_start_type;
357
358 /* private: use NLA_POLICY_*() to set */
359 const u32 bitfield32_valid;
360 const u32 mask;
361 const char *reject_message;
362 const struct nla_policy *nested_policy;
363 const struct netlink_range_validation *range;
364 const struct netlink_range_validation_signed *range_signed;
365 struct {
366 s16 min, max;
367 };
368 int (*validate)(const struct nlattr *attr,
369 struct netlink_ext_ack *extack);
370 };
371};
372
373#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN)
374#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
375
376#define _NLA_POLICY_NESTED(maxattr, policy) \
377 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
378#define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
379 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
380#define NLA_POLICY_NESTED(policy) \
381 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
382#define NLA_POLICY_NESTED_ARRAY(policy) \
383 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
384#define NLA_POLICY_BITFIELD32(valid) \
385 { .type = NLA_BITFIELD32, .bitfield32_valid = valid }
386
387#define __NLA_IS_UINT_TYPE(tp) \
388 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || \
389 tp == NLA_U64 || tp == NLA_UINT || \
390 tp == NLA_BE16 || tp == NLA_BE32)
391#define __NLA_IS_SINT_TYPE(tp) \
392 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64 || \
393 tp == NLA_SINT)
394
395#define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
396#define NLA_ENSURE_UINT_TYPE(tp) \
397 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
398#define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \
399 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
400 tp == NLA_MSECS || \
401 tp == NLA_BINARY) + tp)
402#define NLA_ENSURE_SINT_TYPE(tp) \
403 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
404#define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \
405 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
406 __NLA_IS_SINT_TYPE(tp) || \
407 tp == NLA_MSECS || \
408 tp == NLA_BINARY) + tp)
409#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
410 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \
411 tp != NLA_REJECT && \
412 tp != NLA_NESTED && \
413 tp != NLA_NESTED_ARRAY) + tp)
414
415#define NLA_POLICY_RANGE(tp, _min, _max) { \
416 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
417 .validation_type = NLA_VALIDATE_RANGE, \
418 .min = _min, \
419 .max = _max \
420}
421
422#define NLA_POLICY_FULL_RANGE(tp, _range) { \
423 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \
424 .validation_type = NLA_VALIDATE_RANGE_PTR, \
425 .range = _range, \
426}
427
428#define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \
429 .type = NLA_ENSURE_SINT_TYPE(tp), \
430 .validation_type = NLA_VALIDATE_RANGE_PTR, \
431 .range_signed = _range, \
432}
433
434#define NLA_POLICY_MIN(tp, _min) { \
435 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
436 .validation_type = NLA_VALIDATE_MIN, \
437 .min = _min, \
438}
439
440#define NLA_POLICY_MAX(tp, _max) { \
441 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
442 .validation_type = NLA_VALIDATE_MAX, \
443 .max = _max, \
444}
445
446#define NLA_POLICY_MASK(tp, _mask) { \
447 .type = NLA_ENSURE_UINT_TYPE(tp), \
448 .validation_type = NLA_VALIDATE_MASK, \
449 .mask = _mask, \
450}
451
452#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \
453 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \
454 .validation_type = NLA_VALIDATE_FUNCTION, \
455 .validate = fn, \
456 .len = __VA_ARGS__ + 0, \
457}
458
459#define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
460#define NLA_POLICY_EXACT_LEN_WARN(_len) { \
461 .type = NLA_BINARY, \
462 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \
463 .min = _len, \
464 .max = _len \
465}
466#define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len)
467
468/**
469 * struct nl_info - netlink source information
470 * @nlh: Netlink message header of original request
471 * @nl_net: Network namespace
472 * @portid: Netlink PORTID of requesting application
473 * @skip_notify: Skip netlink notifications to user space
474 * @skip_notify_kernel: Skip selected in-kernel notifications
475 */
476struct nl_info {
477 struct nlmsghdr *nlh;
478 struct net *nl_net;
479 u32 portid;
480 u8 skip_notify:1,
481 skip_notify_kernel:1;
482};
483
484/**
485 * enum netlink_validation - netlink message/attribute validation levels
486 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
487 * extra data at the end of the message, attributes being longer than
488 * they should be, or unknown attributes being present.
489 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
490 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
491 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
492 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
493 * This can safely be set by the kernel when the given policy has no
494 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
495 * are enforced going forward.
496 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
497 * U8, U16, U32 must have exact size, etc.)
498 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
499 * and unset for other policies.
500 */
501enum netlink_validation {
502 NL_VALIDATE_LIBERAL = 0,
503 NL_VALIDATE_TRAILING = BIT(0),
504 NL_VALIDATE_MAXTYPE = BIT(1),
505 NL_VALIDATE_UNSPEC = BIT(2),
506 NL_VALIDATE_STRICT_ATTRS = BIT(3),
507 NL_VALIDATE_NESTED = BIT(4),
508};
509
510#define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
511 NL_VALIDATE_MAXTYPE)
512#define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
513 NL_VALIDATE_MAXTYPE |\
514 NL_VALIDATE_UNSPEC |\
515 NL_VALIDATE_STRICT_ATTRS |\
516 NL_VALIDATE_NESTED)
517
518int netlink_rcv_skb(struct sk_buff *skb,
519 int (*cb)(struct sk_buff *, struct nlmsghdr *,
520 struct netlink_ext_ack *));
521int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
522 unsigned int group, int report, gfp_t flags);
523
524int __nla_validate(const struct nlattr *head, int len, int maxtype,
525 const struct nla_policy *policy, unsigned int validate,
526 struct netlink_ext_ack *extack);
527int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
528 int len, const struct nla_policy *policy, unsigned int validate,
529 struct netlink_ext_ack *extack);
530int nla_policy_len(const struct nla_policy *, int);
531struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
532ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
533char *nla_strdup(const struct nlattr *nla, gfp_t flags);
534int nla_memcpy(void *dest, const struct nlattr *src, int count);
535int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
536int nla_strcmp(const struct nlattr *nla, const char *str);
537struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
538struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
539 int attrlen, int padattr);
540void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
541struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
542struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
543 int attrlen, int padattr);
544void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
545void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
546 const void *data);
547void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
548 const void *data, int padattr);
549void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
550int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
551int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
552 const void *data, int padattr);
553int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
554int nla_append(struct sk_buff *skb, int attrlen, const void *data);
555
556/**************************************************************************
557 * Netlink Messages
558 **************************************************************************/
559
560/**
561 * nlmsg_msg_size - length of netlink message not including padding
562 * @payload: length of message payload
563 */
564static inline int nlmsg_msg_size(int payload)
565{
566 return NLMSG_HDRLEN + payload;
567}
568
569/**
570 * nlmsg_total_size - length of netlink message including padding
571 * @payload: length of message payload
572 */
573static inline int nlmsg_total_size(int payload)
574{
575 return NLMSG_ALIGN(nlmsg_msg_size(payload));
576}
577
578/**
579 * nlmsg_padlen - length of padding at the message's tail
580 * @payload: length of message payload
581 */
582static inline int nlmsg_padlen(int payload)
583{
584 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
585}
586
587/**
588 * nlmsg_data - head of message payload
589 * @nlh: netlink message header
590 */
591static inline void *nlmsg_data(const struct nlmsghdr *nlh)
592{
593 return (unsigned char *) nlh + NLMSG_HDRLEN;
594}
595
596/**
597 * nlmsg_len - length of message payload
598 * @nlh: netlink message header
599 */
600static inline int nlmsg_len(const struct nlmsghdr *nlh)
601{
602 return nlh->nlmsg_len - NLMSG_HDRLEN;
603}
604
605/**
606 * nlmsg_attrdata - head of attributes data
607 * @nlh: netlink message header
608 * @hdrlen: length of family specific header
609 */
610static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
611 int hdrlen)
612{
613 unsigned char *data = nlmsg_data(nlh);
614 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
615}
616
617/**
618 * nlmsg_attrlen - length of attributes data
619 * @nlh: netlink message header
620 * @hdrlen: length of family specific header
621 */
622static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
623{
624 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
625}
626
627/**
628 * nlmsg_ok - check if the netlink message fits into the remaining bytes
629 * @nlh: netlink message header
630 * @remaining: number of bytes remaining in message stream
631 */
632static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
633{
634 return (remaining >= (int) sizeof(struct nlmsghdr) &&
635 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
636 nlh->nlmsg_len <= remaining);
637}
638
639/**
640 * nlmsg_next - next netlink message in message stream
641 * @nlh: netlink message header
642 * @remaining: number of bytes remaining in message stream
643 *
644 * Returns the next netlink message in the message stream and
645 * decrements remaining by the size of the current message.
646 */
647static inline struct nlmsghdr *
648nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
649{
650 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
651
652 *remaining -= totlen;
653
654 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
655}
656
657/**
658 * nla_parse - Parse a stream of attributes into a tb buffer
659 * @tb: destination array with maxtype+1 elements
660 * @maxtype: maximum attribute type to be expected
661 * @head: head of attribute stream
662 * @len: length of attribute stream
663 * @policy: validation policy
664 * @extack: extended ACK pointer
665 *
666 * Parses a stream of attributes and stores a pointer to each attribute in
667 * the tb array accessible via the attribute type. Attributes with a type
668 * exceeding maxtype will be rejected, policy must be specified, attributes
669 * will be validated in the strictest way possible.
670 *
671 * Returns 0 on success or a negative error code.
672 */
673static inline int nla_parse(struct nlattr **tb, int maxtype,
674 const struct nlattr *head, int len,
675 const struct nla_policy *policy,
676 struct netlink_ext_ack *extack)
677{
678 return __nla_parse(tb, maxtype, head, len, policy,
679 NL_VALIDATE_STRICT, extack);
680}
681
682/**
683 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
684 * @tb: destination array with maxtype+1 elements
685 * @maxtype: maximum attribute type to be expected
686 * @head: head of attribute stream
687 * @len: length of attribute stream
688 * @policy: validation policy
689 * @extack: extended ACK pointer
690 *
691 * Parses a stream of attributes and stores a pointer to each attribute in
692 * the tb array accessible via the attribute type. Attributes with a type
693 * exceeding maxtype will be ignored and attributes from the policy are not
694 * always strictly validated (only for new attributes).
695 *
696 * Returns 0 on success or a negative error code.
697 */
698static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
699 const struct nlattr *head, int len,
700 const struct nla_policy *policy,
701 struct netlink_ext_ack *extack)
702{
703 return __nla_parse(tb, maxtype, head, len, policy,
704 NL_VALIDATE_LIBERAL, extack);
705}
706
707/**
708 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
709 * @tb: destination array with maxtype+1 elements
710 * @maxtype: maximum attribute type to be expected
711 * @head: head of attribute stream
712 * @len: length of attribute stream
713 * @policy: validation policy
714 * @extack: extended ACK pointer
715 *
716 * Parses a stream of attributes and stores a pointer to each attribute in
717 * the tb array accessible via the attribute type. Attributes with a type
718 * exceeding maxtype will be rejected as well as trailing data, but the
719 * policy is not completely strictly validated (only for new attributes).
720 *
721 * Returns 0 on success or a negative error code.
722 */
723static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
724 const struct nlattr *head,
725 int len,
726 const struct nla_policy *policy,
727 struct netlink_ext_ack *extack)
728{
729 return __nla_parse(tb, maxtype, head, len, policy,
730 NL_VALIDATE_DEPRECATED_STRICT, extack);
731}
732
733/**
734 * __nlmsg_parse - parse attributes of a netlink message
735 * @nlh: netlink message header
736 * @hdrlen: length of family specific header
737 * @tb: destination array with maxtype+1 elements
738 * @maxtype: maximum attribute type to be expected
739 * @policy: validation policy
740 * @validate: validation strictness
741 * @extack: extended ACK report struct
742 *
743 * See nla_parse()
744 */
745static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
746 struct nlattr *tb[], int maxtype,
747 const struct nla_policy *policy,
748 unsigned int validate,
749 struct netlink_ext_ack *extack)
750{
751 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
752 NL_SET_ERR_MSG(extack, "Invalid header length");
753 return -EINVAL;
754 }
755
756 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
757 nlmsg_attrlen(nlh, hdrlen), policy, validate,
758 extack);
759}
760
761/**
762 * nlmsg_parse - parse attributes of a netlink message
763 * @nlh: netlink message header
764 * @hdrlen: length of family specific header
765 * @tb: destination array with maxtype+1 elements
766 * @maxtype: maximum attribute type to be expected
767 * @policy: validation policy
768 * @extack: extended ACK report struct
769 *
770 * See nla_parse()
771 */
772static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
773 struct nlattr *tb[], int maxtype,
774 const struct nla_policy *policy,
775 struct netlink_ext_ack *extack)
776{
777 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
778 NL_VALIDATE_STRICT, extack);
779}
780
781/**
782 * nlmsg_parse_deprecated - parse attributes of a netlink message
783 * @nlh: netlink message header
784 * @hdrlen: length of family specific header
785 * @tb: destination array with maxtype+1 elements
786 * @maxtype: maximum attribute type to be expected
787 * @policy: validation policy
788 * @extack: extended ACK report struct
789 *
790 * See nla_parse_deprecated()
791 */
792static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
793 struct nlattr *tb[], int maxtype,
794 const struct nla_policy *policy,
795 struct netlink_ext_ack *extack)
796{
797 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
798 NL_VALIDATE_LIBERAL, extack);
799}
800
801/**
802 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
803 * @nlh: netlink message header
804 * @hdrlen: length of family specific header
805 * @tb: destination array with maxtype+1 elements
806 * @maxtype: maximum attribute type to be expected
807 * @policy: validation policy
808 * @extack: extended ACK report struct
809 *
810 * See nla_parse_deprecated_strict()
811 */
812static inline int
813nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
814 struct nlattr *tb[], int maxtype,
815 const struct nla_policy *policy,
816 struct netlink_ext_ack *extack)
817{
818 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
819 NL_VALIDATE_DEPRECATED_STRICT, extack);
820}
821
822/**
823 * nlmsg_find_attr - find a specific attribute in a netlink message
824 * @nlh: netlink message header
825 * @hdrlen: length of familiy specific header
826 * @attrtype: type of attribute to look for
827 *
828 * Returns the first attribute which matches the specified type.
829 */
830static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
831 int hdrlen, int attrtype)
832{
833 return nla_find(nlmsg_attrdata(nlh, hdrlen),
834 nlmsg_attrlen(nlh, hdrlen), attrtype);
835}
836
837/**
838 * nla_validate_deprecated - Validate a stream of attributes
839 * @head: head of attribute stream
840 * @len: length of attribute stream
841 * @maxtype: maximum attribute type to be expected
842 * @policy: validation policy
843 * @extack: extended ACK report struct
844 *
845 * Validates all attributes in the specified attribute stream against the
846 * specified policy. Validation is done in liberal mode.
847 * See documenation of struct nla_policy for more details.
848 *
849 * Returns 0 on success or a negative error code.
850 */
851static inline int nla_validate_deprecated(const struct nlattr *head, int len,
852 int maxtype,
853 const struct nla_policy *policy,
854 struct netlink_ext_ack *extack)
855{
856 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
857 extack);
858}
859
860/**
861 * nla_validate - Validate a stream of attributes
862 * @head: head of attribute stream
863 * @len: length of attribute stream
864 * @maxtype: maximum attribute type to be expected
865 * @policy: validation policy
866 * @extack: extended ACK report struct
867 *
868 * Validates all attributes in the specified attribute stream against the
869 * specified policy. Validation is done in strict mode.
870 * See documenation of struct nla_policy for more details.
871 *
872 * Returns 0 on success or a negative error code.
873 */
874static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
875 const struct nla_policy *policy,
876 struct netlink_ext_ack *extack)
877{
878 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
879 extack);
880}
881
882/**
883 * nlmsg_validate_deprecated - validate a netlink message including attributes
884 * @nlh: netlinket message header
885 * @hdrlen: length of familiy specific header
886 * @maxtype: maximum attribute type to be expected
887 * @policy: validation policy
888 * @extack: extended ACK report struct
889 */
890static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
891 int hdrlen, int maxtype,
892 const struct nla_policy *policy,
893 struct netlink_ext_ack *extack)
894{
895 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
896 return -EINVAL;
897
898 return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
899 nlmsg_attrlen(nlh, hdrlen), maxtype,
900 policy, NL_VALIDATE_LIBERAL, extack);
901}
902
903
904
905/**
906 * nlmsg_report - need to report back to application?
907 * @nlh: netlink message header
908 *
909 * Returns 1 if a report back to the application is requested.
910 */
911static inline int nlmsg_report(const struct nlmsghdr *nlh)
912{
913 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
914}
915
916/**
917 * nlmsg_seq - return the seq number of netlink message
918 * @nlh: netlink message header
919 *
920 * Returns 0 if netlink message is NULL
921 */
922static inline u32 nlmsg_seq(const struct nlmsghdr *nlh)
923{
924 return nlh ? nlh->nlmsg_seq : 0;
925}
926
927/**
928 * nlmsg_for_each_attr - iterate over a stream of attributes
929 * @pos: loop counter, set to current attribute
930 * @nlh: netlink message header
931 * @hdrlen: length of familiy specific header
932 * @rem: initialized to len, holds bytes currently remaining in stream
933 */
934#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
935 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
936 nlmsg_attrlen(nlh, hdrlen), rem)
937
938/**
939 * nlmsg_put - Add a new netlink message to an skb
940 * @skb: socket buffer to store message in
941 * @portid: netlink PORTID of requesting application
942 * @seq: sequence number of message
943 * @type: message type
944 * @payload: length of message payload
945 * @flags: message flags
946 *
947 * Returns NULL if the tailroom of the skb is insufficient to store
948 * the message header and payload.
949 */
950static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
951 int type, int payload, int flags)
952{
953 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
954 return NULL;
955
956 return __nlmsg_put(skb, portid, seq, type, payload, flags);
957}
958
959/**
960 * nlmsg_append - Add more data to a nlmsg in a skb
961 * @skb: socket buffer to store message in
962 * @size: length of message payload
963 *
964 * Append data to an existing nlmsg, used when constructing a message
965 * with multiple fixed-format headers (which is rare).
966 * Returns NULL if the tailroom of the skb is insufficient to store
967 * the extra payload.
968 */
969static inline void *nlmsg_append(struct sk_buff *skb, u32 size)
970{
971 if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size)))
972 return NULL;
973
974 if (NLMSG_ALIGN(size) - size)
975 memset(skb_tail_pointer(skb) + size, 0,
976 NLMSG_ALIGN(size) - size);
977 return __skb_put(skb, NLMSG_ALIGN(size));
978}
979
980/**
981 * nlmsg_put_answer - Add a new callback based netlink message to an skb
982 * @skb: socket buffer to store message in
983 * @cb: netlink callback
984 * @type: message type
985 * @payload: length of message payload
986 * @flags: message flags
987 *
988 * Returns NULL if the tailroom of the skb is insufficient to store
989 * the message header and payload.
990 */
991static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
992 struct netlink_callback *cb,
993 int type, int payload,
994 int flags)
995{
996 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
997 type, payload, flags);
998}
999
1000/**
1001 * nlmsg_new - Allocate a new netlink message
1002 * @payload: size of the message payload
1003 * @flags: the type of memory to allocate.
1004 *
1005 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
1006 * and a good default is needed.
1007 */
1008static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
1009{
1010 return alloc_skb(nlmsg_total_size(payload), flags);
1011}
1012
1013/**
1014 * nlmsg_new_large - Allocate a new netlink message with non-contiguous
1015 * physical memory
1016 * @payload: size of the message payload
1017 *
1018 * The allocated skb is unable to have frag page for shinfo->frags*,
1019 * as the NULL setting for skb->head in netlink_skb_destructor() will
1020 * bypass most of the handling in skb_release_data()
1021 */
1022static inline struct sk_buff *nlmsg_new_large(size_t payload)
1023{
1024 return netlink_alloc_large_skb(nlmsg_total_size(payload), 0);
1025}
1026
1027/**
1028 * nlmsg_end - Finalize a netlink message
1029 * @skb: socket buffer the message is stored in
1030 * @nlh: netlink message header
1031 *
1032 * Corrects the netlink message header to include the appeneded
1033 * attributes. Only necessary if attributes have been added to
1034 * the message.
1035 */
1036static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
1037{
1038 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
1039}
1040
1041/**
1042 * nlmsg_get_pos - return current position in netlink message
1043 * @skb: socket buffer the message is stored in
1044 *
1045 * Returns a pointer to the current tail of the message.
1046 */
1047static inline void *nlmsg_get_pos(struct sk_buff *skb)
1048{
1049 return skb_tail_pointer(skb);
1050}
1051
1052/**
1053 * nlmsg_trim - Trim message to a mark
1054 * @skb: socket buffer the message is stored in
1055 * @mark: mark to trim to
1056 *
1057 * Trims the message to the provided mark.
1058 */
1059static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1060{
1061 if (mark) {
1062 WARN_ON((unsigned char *) mark < skb->data);
1063 skb_trim(skb, (unsigned char *) mark - skb->data);
1064 }
1065}
1066
1067/**
1068 * nlmsg_cancel - Cancel construction of a netlink message
1069 * @skb: socket buffer the message is stored in
1070 * @nlh: netlink message header
1071 *
1072 * Removes the complete netlink message including all
1073 * attributes from the socket buffer again.
1074 */
1075static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1076{
1077 nlmsg_trim(skb, nlh);
1078}
1079
1080/**
1081 * nlmsg_free - free a netlink message
1082 * @skb: socket buffer of netlink message
1083 */
1084static inline void nlmsg_free(struct sk_buff *skb)
1085{
1086 kfree_skb(skb);
1087}
1088
1089/**
1090 * nlmsg_multicast_filtered - multicast a netlink message with filter function
1091 * @sk: netlink socket to spread messages to
1092 * @skb: netlink message as socket buffer
1093 * @portid: own netlink portid to avoid sending to yourself
1094 * @group: multicast group id
1095 * @flags: allocation flags
1096 * @filter: filter function
1097 * @filter_data: filter function private data
1098 *
1099 * Return: 0 on success, negative error code for failure.
1100 */
1101static inline int nlmsg_multicast_filtered(struct sock *sk, struct sk_buff *skb,
1102 u32 portid, unsigned int group,
1103 gfp_t flags,
1104 netlink_filter_fn filter,
1105 void *filter_data)
1106{
1107 int err;
1108
1109 NETLINK_CB(skb).dst_group = group;
1110
1111 err = netlink_broadcast_filtered(sk, skb, portid, group, flags,
1112 filter, filter_data);
1113 if (err > 0)
1114 err = 0;
1115
1116 return err;
1117}
1118
1119/**
1120 * nlmsg_multicast - multicast a netlink message
1121 * @sk: netlink socket to spread messages to
1122 * @skb: netlink message as socket buffer
1123 * @portid: own netlink portid to avoid sending to yourself
1124 * @group: multicast group id
1125 * @flags: allocation flags
1126 */
1127static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1128 u32 portid, unsigned int group, gfp_t flags)
1129{
1130 return nlmsg_multicast_filtered(sk, skb, portid, group, flags,
1131 NULL, NULL);
1132}
1133
1134/**
1135 * nlmsg_unicast - unicast a netlink message
1136 * @sk: netlink socket to spread message to
1137 * @skb: netlink message as socket buffer
1138 * @portid: netlink portid of the destination socket
1139 */
1140static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1141{
1142 int err;
1143
1144 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1145 if (err > 0)
1146 err = 0;
1147
1148 return err;
1149}
1150
1151/**
1152 * nlmsg_for_each_msg - iterate over a stream of messages
1153 * @pos: loop counter, set to current message
1154 * @head: head of message stream
1155 * @len: length of message stream
1156 * @rem: initialized to len, holds bytes currently remaining in stream
1157 */
1158#define nlmsg_for_each_msg(pos, head, len, rem) \
1159 for (pos = head, rem = len; \
1160 nlmsg_ok(pos, rem); \
1161 pos = nlmsg_next(pos, &(rem)))
1162
1163/**
1164 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1165 * @cb: netlink callback structure that stores the sequence number
1166 * @nlh: netlink message header to write the flag to
1167 *
1168 * This function checks if the sequence (generation) number changed during dump
1169 * and if it did, advertises it in the netlink message header.
1170 *
1171 * The correct way to use it is to set cb->seq to the generation counter when
1172 * all locks for dumping have been acquired, and then call this function for
1173 * each message that is generated.
1174 *
1175 * Note that due to initialisation concerns, 0 is an invalid sequence number
1176 * and must not be used by code that uses this functionality.
1177 */
1178static inline void
1179nl_dump_check_consistent(struct netlink_callback *cb,
1180 struct nlmsghdr *nlh)
1181{
1182 if (cb->prev_seq && cb->seq != cb->prev_seq)
1183 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1184 cb->prev_seq = cb->seq;
1185}
1186
1187/**************************************************************************
1188 * Netlink Attributes
1189 **************************************************************************/
1190
1191/**
1192 * nla_attr_size - length of attribute not including padding
1193 * @payload: length of payload
1194 */
1195static inline int nla_attr_size(int payload)
1196{
1197 return NLA_HDRLEN + payload;
1198}
1199
1200/**
1201 * nla_total_size - total length of attribute including padding
1202 * @payload: length of payload
1203 */
1204static inline int nla_total_size(int payload)
1205{
1206 return NLA_ALIGN(nla_attr_size(payload));
1207}
1208
1209/**
1210 * nla_padlen - length of padding at the tail of attribute
1211 * @payload: length of payload
1212 */
1213static inline int nla_padlen(int payload)
1214{
1215 return nla_total_size(payload) - nla_attr_size(payload);
1216}
1217
1218/**
1219 * nla_type - attribute type
1220 * @nla: netlink attribute
1221 */
1222static inline int nla_type(const struct nlattr *nla)
1223{
1224 return nla->nla_type & NLA_TYPE_MASK;
1225}
1226
1227/**
1228 * nla_data - head of payload
1229 * @nla: netlink attribute
1230 */
1231static inline void *nla_data(const struct nlattr *nla)
1232{
1233 return (char *) nla + NLA_HDRLEN;
1234}
1235
1236/**
1237 * nla_len - length of payload
1238 * @nla: netlink attribute
1239 */
1240static inline u16 nla_len(const struct nlattr *nla)
1241{
1242 return nla->nla_len - NLA_HDRLEN;
1243}
1244
1245/**
1246 * nla_ok - check if the netlink attribute fits into the remaining bytes
1247 * @nla: netlink attribute
1248 * @remaining: number of bytes remaining in attribute stream
1249 */
1250static inline int nla_ok(const struct nlattr *nla, int remaining)
1251{
1252 return remaining >= (int) sizeof(*nla) &&
1253 nla->nla_len >= sizeof(*nla) &&
1254 nla->nla_len <= remaining;
1255}
1256
1257/**
1258 * nla_next - next netlink attribute in attribute stream
1259 * @nla: netlink attribute
1260 * @remaining: number of bytes remaining in attribute stream
1261 *
1262 * Returns the next netlink attribute in the attribute stream and
1263 * decrements remaining by the size of the current attribute.
1264 */
1265static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1266{
1267 unsigned int totlen = NLA_ALIGN(nla->nla_len);
1268
1269 *remaining -= totlen;
1270 return (struct nlattr *) ((char *) nla + totlen);
1271}
1272
1273/**
1274 * nla_find_nested - find attribute in a set of nested attributes
1275 * @nla: attribute containing the nested attributes
1276 * @attrtype: type of attribute to look for
1277 *
1278 * Returns the first attribute which matches the specified type.
1279 */
1280static inline struct nlattr *
1281nla_find_nested(const struct nlattr *nla, int attrtype)
1282{
1283 return nla_find(nla_data(nla), nla_len(nla), attrtype);
1284}
1285
1286/**
1287 * nla_parse_nested - parse nested attributes
1288 * @tb: destination array with maxtype+1 elements
1289 * @maxtype: maximum attribute type to be expected
1290 * @nla: attribute containing the nested attributes
1291 * @policy: validation policy
1292 * @extack: extended ACK report struct
1293 *
1294 * See nla_parse()
1295 */
1296static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1297 const struct nlattr *nla,
1298 const struct nla_policy *policy,
1299 struct netlink_ext_ack *extack)
1300{
1301 if (!(nla->nla_type & NLA_F_NESTED)) {
1302 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1303 return -EINVAL;
1304 }
1305
1306 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1307 NL_VALIDATE_STRICT, extack);
1308}
1309
1310/**
1311 * nla_parse_nested_deprecated - parse nested attributes
1312 * @tb: destination array with maxtype+1 elements
1313 * @maxtype: maximum attribute type to be expected
1314 * @nla: attribute containing the nested attributes
1315 * @policy: validation policy
1316 * @extack: extended ACK report struct
1317 *
1318 * See nla_parse_deprecated()
1319 */
1320static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1321 const struct nlattr *nla,
1322 const struct nla_policy *policy,
1323 struct netlink_ext_ack *extack)
1324{
1325 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1326 NL_VALIDATE_LIBERAL, extack);
1327}
1328
1329/**
1330 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1331 * @skb: socket buffer to add attribute to
1332 * @attrtype: attribute type
1333 * @value: numeric value
1334 */
1335static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1336{
1337 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
1338 u8 tmp = value;
1339
1340 return nla_put(skb, attrtype, sizeof(u8), &tmp);
1341}
1342
1343/**
1344 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1345 * @skb: socket buffer to add attribute to
1346 * @attrtype: attribute type
1347 * @value: numeric value
1348 */
1349static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1350{
1351 u16 tmp = value;
1352
1353 return nla_put(skb, attrtype, sizeof(u16), &tmp);
1354}
1355
1356/**
1357 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1358 * @skb: socket buffer to add attribute to
1359 * @attrtype: attribute type
1360 * @value: numeric value
1361 */
1362static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1363{
1364 __be16 tmp = value;
1365
1366 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1367}
1368
1369/**
1370 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1371 * @skb: socket buffer to add attribute to
1372 * @attrtype: attribute type
1373 * @value: numeric value
1374 */
1375static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1376{
1377 __be16 tmp = value;
1378
1379 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1380}
1381
1382/**
1383 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1384 * @skb: socket buffer to add attribute to
1385 * @attrtype: attribute type
1386 * @value: numeric value
1387 */
1388static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1389{
1390 __le16 tmp = value;
1391
1392 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1393}
1394
1395/**
1396 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1397 * @skb: socket buffer to add attribute to
1398 * @attrtype: attribute type
1399 * @value: numeric value
1400 */
1401static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1402{
1403 u32 tmp = value;
1404
1405 return nla_put(skb, attrtype, sizeof(u32), &tmp);
1406}
1407
1408/**
1409 * nla_put_uint - Add a variable-size unsigned int to a socket buffer
1410 * @skb: socket buffer to add attribute to
1411 * @attrtype: attribute type
1412 * @value: numeric value
1413 */
1414static inline int nla_put_uint(struct sk_buff *skb, int attrtype, u64 value)
1415{
1416 u64 tmp64 = value;
1417 u32 tmp32 = value;
1418
1419 if (tmp64 == tmp32)
1420 return nla_put_u32(skb, attrtype, tmp32);
1421 return nla_put(skb, attrtype, sizeof(u64), &tmp64);
1422}
1423
1424/**
1425 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1426 * @skb: socket buffer to add attribute to
1427 * @attrtype: attribute type
1428 * @value: numeric value
1429 */
1430static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1431{
1432 __be32 tmp = value;
1433
1434 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1435}
1436
1437/**
1438 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1439 * @skb: socket buffer to add attribute to
1440 * @attrtype: attribute type
1441 * @value: numeric value
1442 */
1443static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1444{
1445 __be32 tmp = value;
1446
1447 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1448}
1449
1450/**
1451 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1452 * @skb: socket buffer to add attribute to
1453 * @attrtype: attribute type
1454 * @value: numeric value
1455 */
1456static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1457{
1458 __le32 tmp = value;
1459
1460 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1461}
1462
1463/**
1464 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1465 * @skb: socket buffer to add attribute to
1466 * @attrtype: attribute type
1467 * @value: numeric value
1468 * @padattr: attribute type for the padding
1469 */
1470static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1471 u64 value, int padattr)
1472{
1473 u64 tmp = value;
1474
1475 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1476}
1477
1478/**
1479 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1480 * @skb: socket buffer to add attribute to
1481 * @attrtype: attribute type
1482 * @value: numeric value
1483 * @padattr: attribute type for the padding
1484 */
1485static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1486 int padattr)
1487{
1488 __be64 tmp = value;
1489
1490 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1491}
1492
1493/**
1494 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1495 * @skb: socket buffer to add attribute to
1496 * @attrtype: attribute type
1497 * @value: numeric value
1498 * @padattr: attribute type for the padding
1499 */
1500static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1501 int padattr)
1502{
1503 __be64 tmp = value;
1504
1505 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1506 padattr);
1507}
1508
1509/**
1510 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1511 * @skb: socket buffer to add attribute to
1512 * @attrtype: attribute type
1513 * @value: numeric value
1514 * @padattr: attribute type for the padding
1515 */
1516static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1517 int padattr)
1518{
1519 __le64 tmp = value;
1520
1521 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1522}
1523
1524/**
1525 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1526 * @skb: socket buffer to add attribute to
1527 * @attrtype: attribute type
1528 * @value: numeric value
1529 */
1530static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1531{
1532 s8 tmp = value;
1533
1534 return nla_put(skb, attrtype, sizeof(s8), &tmp);
1535}
1536
1537/**
1538 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1539 * @skb: socket buffer to add attribute to
1540 * @attrtype: attribute type
1541 * @value: numeric value
1542 */
1543static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1544{
1545 s16 tmp = value;
1546
1547 return nla_put(skb, attrtype, sizeof(s16), &tmp);
1548}
1549
1550/**
1551 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1552 * @skb: socket buffer to add attribute to
1553 * @attrtype: attribute type
1554 * @value: numeric value
1555 */
1556static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1557{
1558 s32 tmp = value;
1559
1560 return nla_put(skb, attrtype, sizeof(s32), &tmp);
1561}
1562
1563/**
1564 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1565 * @skb: socket buffer to add attribute to
1566 * @attrtype: attribute type
1567 * @value: numeric value
1568 * @padattr: attribute type for the padding
1569 */
1570static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1571 int padattr)
1572{
1573 s64 tmp = value;
1574
1575 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1576}
1577
1578/**
1579 * nla_put_sint - Add a variable-size signed int to a socket buffer
1580 * @skb: socket buffer to add attribute to
1581 * @attrtype: attribute type
1582 * @value: numeric value
1583 */
1584static inline int nla_put_sint(struct sk_buff *skb, int attrtype, s64 value)
1585{
1586 s64 tmp64 = value;
1587 s32 tmp32 = value;
1588
1589 if (tmp64 == tmp32)
1590 return nla_put_s32(skb, attrtype, tmp32);
1591 return nla_put(skb, attrtype, sizeof(s64), &tmp64);
1592}
1593
1594/**
1595 * nla_put_string - Add a string netlink attribute to a socket buffer
1596 * @skb: socket buffer to add attribute to
1597 * @attrtype: attribute type
1598 * @str: NUL terminated string
1599 */
1600static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1601 const char *str)
1602{
1603 return nla_put(skb, attrtype, strlen(str) + 1, str);
1604}
1605
1606/**
1607 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1608 * @skb: socket buffer to add attribute to
1609 * @attrtype: attribute type
1610 */
1611static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1612{
1613 return nla_put(skb, attrtype, 0, NULL);
1614}
1615
1616/**
1617 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1618 * @skb: socket buffer to add attribute to
1619 * @attrtype: attribute type
1620 * @njiffies: number of jiffies to convert to msecs
1621 * @padattr: attribute type for the padding
1622 */
1623static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1624 unsigned long njiffies, int padattr)
1625{
1626 u64 tmp = jiffies_to_msecs(njiffies);
1627
1628 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1629}
1630
1631/**
1632 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1633 * buffer
1634 * @skb: socket buffer to add attribute to
1635 * @attrtype: attribute type
1636 * @addr: IPv4 address
1637 */
1638static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1639 __be32 addr)
1640{
1641 __be32 tmp = addr;
1642
1643 return nla_put_be32(skb, attrtype, tmp);
1644}
1645
1646/**
1647 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1648 * buffer
1649 * @skb: socket buffer to add attribute to
1650 * @attrtype: attribute type
1651 * @addr: IPv6 address
1652 */
1653static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1654 const struct in6_addr *addr)
1655{
1656 return nla_put(skb, attrtype, sizeof(*addr), addr);
1657}
1658
1659/**
1660 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1661 * @skb: socket buffer to add attribute to
1662 * @attrtype: attribute type
1663 * @value: value carrying bits
1664 * @selector: selector of valid bits
1665 */
1666static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1667 __u32 value, __u32 selector)
1668{
1669 struct nla_bitfield32 tmp = { value, selector, };
1670
1671 return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1672}
1673
1674/**
1675 * nla_get_u32 - return payload of u32 attribute
1676 * @nla: u32 netlink attribute
1677 */
1678static inline u32 nla_get_u32(const struct nlattr *nla)
1679{
1680 return *(u32 *) nla_data(nla);
1681}
1682
1683/**
1684 * nla_get_be32 - return payload of __be32 attribute
1685 * @nla: __be32 netlink attribute
1686 */
1687static inline __be32 nla_get_be32(const struct nlattr *nla)
1688{
1689 return *(__be32 *) nla_data(nla);
1690}
1691
1692/**
1693 * nla_get_le32 - return payload of __le32 attribute
1694 * @nla: __le32 netlink attribute
1695 */
1696static inline __le32 nla_get_le32(const struct nlattr *nla)
1697{
1698 return *(__le32 *) nla_data(nla);
1699}
1700
1701/**
1702 * nla_get_u16 - return payload of u16 attribute
1703 * @nla: u16 netlink attribute
1704 */
1705static inline u16 nla_get_u16(const struct nlattr *nla)
1706{
1707 return *(u16 *) nla_data(nla);
1708}
1709
1710/**
1711 * nla_get_be16 - return payload of __be16 attribute
1712 * @nla: __be16 netlink attribute
1713 */
1714static inline __be16 nla_get_be16(const struct nlattr *nla)
1715{
1716 return *(__be16 *) nla_data(nla);
1717}
1718
1719/**
1720 * nla_get_le16 - return payload of __le16 attribute
1721 * @nla: __le16 netlink attribute
1722 */
1723static inline __le16 nla_get_le16(const struct nlattr *nla)
1724{
1725 return *(__le16 *) nla_data(nla);
1726}
1727
1728/**
1729 * nla_get_u8 - return payload of u8 attribute
1730 * @nla: u8 netlink attribute
1731 */
1732static inline u8 nla_get_u8(const struct nlattr *nla)
1733{
1734 return *(u8 *) nla_data(nla);
1735}
1736
1737/**
1738 * nla_get_u64 - return payload of u64 attribute
1739 * @nla: u64 netlink attribute
1740 */
1741static inline u64 nla_get_u64(const struct nlattr *nla)
1742{
1743 u64 tmp;
1744
1745 nla_memcpy(&tmp, nla, sizeof(tmp));
1746
1747 return tmp;
1748}
1749
1750/**
1751 * nla_get_uint - return payload of uint attribute
1752 * @nla: uint netlink attribute
1753 */
1754static inline u64 nla_get_uint(const struct nlattr *nla)
1755{
1756 if (nla_len(nla) == sizeof(u32))
1757 return nla_get_u32(nla);
1758 return nla_get_u64(nla);
1759}
1760
1761/**
1762 * nla_get_be64 - return payload of __be64 attribute
1763 * @nla: __be64 netlink attribute
1764 */
1765static inline __be64 nla_get_be64(const struct nlattr *nla)
1766{
1767 __be64 tmp;
1768
1769 nla_memcpy(&tmp, nla, sizeof(tmp));
1770
1771 return tmp;
1772}
1773
1774/**
1775 * nla_get_le64 - return payload of __le64 attribute
1776 * @nla: __le64 netlink attribute
1777 */
1778static inline __le64 nla_get_le64(const struct nlattr *nla)
1779{
1780 return *(__le64 *) nla_data(nla);
1781}
1782
1783/**
1784 * nla_get_s32 - return payload of s32 attribute
1785 * @nla: s32 netlink attribute
1786 */
1787static inline s32 nla_get_s32(const struct nlattr *nla)
1788{
1789 return *(s32 *) nla_data(nla);
1790}
1791
1792/**
1793 * nla_get_s16 - return payload of s16 attribute
1794 * @nla: s16 netlink attribute
1795 */
1796static inline s16 nla_get_s16(const struct nlattr *nla)
1797{
1798 return *(s16 *) nla_data(nla);
1799}
1800
1801/**
1802 * nla_get_s8 - return payload of s8 attribute
1803 * @nla: s8 netlink attribute
1804 */
1805static inline s8 nla_get_s8(const struct nlattr *nla)
1806{
1807 return *(s8 *) nla_data(nla);
1808}
1809
1810/**
1811 * nla_get_s64 - return payload of s64 attribute
1812 * @nla: s64 netlink attribute
1813 */
1814static inline s64 nla_get_s64(const struct nlattr *nla)
1815{
1816 s64 tmp;
1817
1818 nla_memcpy(&tmp, nla, sizeof(tmp));
1819
1820 return tmp;
1821}
1822
1823/**
1824 * nla_get_sint - return payload of uint attribute
1825 * @nla: uint netlink attribute
1826 */
1827static inline s64 nla_get_sint(const struct nlattr *nla)
1828{
1829 if (nla_len(nla) == sizeof(s32))
1830 return nla_get_s32(nla);
1831 return nla_get_s64(nla);
1832}
1833
1834/**
1835 * nla_get_flag - return payload of flag attribute
1836 * @nla: flag netlink attribute
1837 */
1838static inline int nla_get_flag(const struct nlattr *nla)
1839{
1840 return !!nla;
1841}
1842
1843/**
1844 * nla_get_msecs - return payload of msecs attribute
1845 * @nla: msecs netlink attribute
1846 *
1847 * Returns the number of milliseconds in jiffies.
1848 */
1849static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1850{
1851 u64 msecs = nla_get_u64(nla);
1852
1853 return msecs_to_jiffies((unsigned long) msecs);
1854}
1855
1856/**
1857 * nla_get_in_addr - return payload of IPv4 address attribute
1858 * @nla: IPv4 address netlink attribute
1859 */
1860static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1861{
1862 return *(__be32 *) nla_data(nla);
1863}
1864
1865/**
1866 * nla_get_in6_addr - return payload of IPv6 address attribute
1867 * @nla: IPv6 address netlink attribute
1868 */
1869static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1870{
1871 struct in6_addr tmp;
1872
1873 nla_memcpy(&tmp, nla, sizeof(tmp));
1874 return tmp;
1875}
1876
1877/**
1878 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1879 * @nla: nla_bitfield32 attribute
1880 */
1881static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1882{
1883 struct nla_bitfield32 tmp;
1884
1885 nla_memcpy(&tmp, nla, sizeof(tmp));
1886 return tmp;
1887}
1888
1889/**
1890 * nla_memdup - duplicate attribute memory (kmemdup)
1891 * @src: netlink attribute to duplicate from
1892 * @gfp: GFP mask
1893 */
1894static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1895{
1896 return kmemdup(nla_data(src), nla_len(src), gfp);
1897}
1898
1899/**
1900 * nla_nest_start_noflag - Start a new level of nested attributes
1901 * @skb: socket buffer to add attributes to
1902 * @attrtype: attribute type of container
1903 *
1904 * This function exists for backward compatibility to use in APIs which never
1905 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1906 * nla_nest_start() which sets the flag.
1907 *
1908 * Returns the container attribute or NULL on error
1909 */
1910static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1911 int attrtype)
1912{
1913 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1914
1915 if (nla_put(skb, attrtype, 0, NULL) < 0)
1916 return NULL;
1917
1918 return start;
1919}
1920
1921/**
1922 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1923 * @skb: socket buffer to add attributes to
1924 * @attrtype: attribute type of container
1925 *
1926 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1927 * flag. This is the preferred function to use in new code.
1928 *
1929 * Returns the container attribute or NULL on error
1930 */
1931static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1932{
1933 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1934}
1935
1936/**
1937 * nla_nest_end - Finalize nesting of attributes
1938 * @skb: socket buffer the attributes are stored in
1939 * @start: container attribute
1940 *
1941 * Corrects the container attribute header to include the all
1942 * appeneded attributes.
1943 *
1944 * Returns the total data length of the skb.
1945 */
1946static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1947{
1948 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1949 return skb->len;
1950}
1951
1952/**
1953 * nla_nest_cancel - Cancel nesting of attributes
1954 * @skb: socket buffer the message is stored in
1955 * @start: container attribute
1956 *
1957 * Removes the container attribute and including all nested
1958 * attributes. Returns -EMSGSIZE
1959 */
1960static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1961{
1962 nlmsg_trim(skb, start);
1963}
1964
1965/**
1966 * __nla_validate_nested - Validate a stream of nested attributes
1967 * @start: container attribute
1968 * @maxtype: maximum attribute type to be expected
1969 * @policy: validation policy
1970 * @validate: validation strictness
1971 * @extack: extended ACK report struct
1972 *
1973 * Validates all attributes in the nested attribute stream against the
1974 * specified policy. Attributes with a type exceeding maxtype will be
1975 * ignored. See documenation of struct nla_policy for more details.
1976 *
1977 * Returns 0 on success or a negative error code.
1978 */
1979static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1980 const struct nla_policy *policy,
1981 unsigned int validate,
1982 struct netlink_ext_ack *extack)
1983{
1984 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1985 validate, extack);
1986}
1987
1988static inline int
1989nla_validate_nested(const struct nlattr *start, int maxtype,
1990 const struct nla_policy *policy,
1991 struct netlink_ext_ack *extack)
1992{
1993 return __nla_validate_nested(start, maxtype, policy,
1994 NL_VALIDATE_STRICT, extack);
1995}
1996
1997static inline int
1998nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1999 const struct nla_policy *policy,
2000 struct netlink_ext_ack *extack)
2001{
2002 return __nla_validate_nested(start, maxtype, policy,
2003 NL_VALIDATE_LIBERAL, extack);
2004}
2005
2006/**
2007 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
2008 * @skb: socket buffer the message is stored in
2009 *
2010 * Return true if padding is needed to align the next attribute (nla_data()) to
2011 * a 64-bit aligned area.
2012 */
2013static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
2014{
2015#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2016 /* The nlattr header is 4 bytes in size, that's why we test
2017 * if the skb->data _is_ aligned. A NOP attribute, plus
2018 * nlattr header for next attribute, will make nla_data()
2019 * 8-byte aligned.
2020 */
2021 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
2022 return true;
2023#endif
2024 return false;
2025}
2026
2027/**
2028 * nla_align_64bit - 64-bit align the nla_data() of next attribute
2029 * @skb: socket buffer the message is stored in
2030 * @padattr: attribute type for the padding
2031 *
2032 * Conditionally emit a padding netlink attribute in order to make
2033 * the next attribute we emit have a 64-bit aligned nla_data() area.
2034 * This will only be done in architectures which do not have
2035 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
2036 *
2037 * Returns zero on success or a negative error code.
2038 */
2039static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
2040{
2041 if (nla_need_padding_for_64bit(skb) &&
2042 !nla_reserve(skb, padattr, 0))
2043 return -EMSGSIZE;
2044
2045 return 0;
2046}
2047
2048/**
2049 * nla_total_size_64bit - total length of attribute including padding
2050 * @payload: length of payload
2051 */
2052static inline int nla_total_size_64bit(int payload)
2053{
2054 return NLA_ALIGN(nla_attr_size(payload))
2055#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2056 + NLA_ALIGN(nla_attr_size(0))
2057#endif
2058 ;
2059}
2060
2061/**
2062 * nla_for_each_attr - iterate over a stream of attributes
2063 * @pos: loop counter, set to current attribute
2064 * @head: head of attribute stream
2065 * @len: length of attribute stream
2066 * @rem: initialized to len, holds bytes currently remaining in stream
2067 */
2068#define nla_for_each_attr(pos, head, len, rem) \
2069 for (pos = head, rem = len; \
2070 nla_ok(pos, rem); \
2071 pos = nla_next(pos, &(rem)))
2072
2073/**
2074 * nla_for_each_nested - iterate over nested attributes
2075 * @pos: loop counter, set to current attribute
2076 * @nla: attribute containing the nested attributes
2077 * @rem: initialized to len, holds bytes currently remaining in stream
2078 */
2079#define nla_for_each_nested(pos, nla, rem) \
2080 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
2081
2082/**
2083 * nla_is_last - Test if attribute is last in stream
2084 * @nla: attribute to test
2085 * @rem: bytes remaining in stream
2086 */
2087static inline bool nla_is_last(const struct nlattr *nla, int rem)
2088{
2089 return nla->nla_len == rem;
2090}
2091
2092void nla_get_range_unsigned(const struct nla_policy *pt,
2093 struct netlink_range_validation *range);
2094void nla_get_range_signed(const struct nla_policy *pt,
2095 struct netlink_range_validation_signed *range);
2096
2097struct netlink_policy_dump_state;
2098
2099int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
2100 const struct nla_policy *policy,
2101 unsigned int maxtype);
2102int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
2103 const struct nla_policy *policy,
2104 unsigned int maxtype);
2105bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
2106int netlink_policy_dump_write(struct sk_buff *skb,
2107 struct netlink_policy_dump_state *state);
2108int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
2109int netlink_policy_dump_write_attr(struct sk_buff *skb,
2110 const struct nla_policy *pt,
2111 int nestattr);
2112void netlink_policy_dump_free(struct netlink_policy_dump_state *state);
2113
2114#endif