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1#ifndef __NET_NETLINK_H
2#define __NET_NETLINK_H
3
4#include <linux/types.h>
5#include <linux/netlink.h>
6#include <linux/jiffies.h>
7
8/* ========================================================================
9 * Netlink Messages and Attributes Interface (As Seen On TV)
10 * ------------------------------------------------------------------------
11 * Messages Interface
12 * ------------------------------------------------------------------------
13 *
14 * Message Format:
15 * <--- nlmsg_total_size(payload) --->
16 * <-- nlmsg_msg_size(payload) ->
17 * +----------+- - -+-------------+- - -+-------- - -
18 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr
19 * +----------+- - -+-------------+- - -+-------- - -
20 * nlmsg_data(nlh)---^ ^
21 * nlmsg_next(nlh)-----------------------+
22 *
23 * Payload Format:
24 * <---------------------- nlmsg_len(nlh) --------------------->
25 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
26 * +----------------------+- - -+--------------------------------+
27 * | Family Header | Pad | Attributes |
28 * +----------------------+- - -+--------------------------------+
29 * nlmsg_attrdata(nlh, hdrlen)---^
30 *
31 * Data Structures:
32 * struct nlmsghdr netlink message header
33 *
34 * Message Construction:
35 * nlmsg_new() create a new netlink message
36 * nlmsg_put() add a netlink message to an skb
37 * nlmsg_put_answer() callback based nlmsg_put()
38 * nlmsg_end() finalize netlink message
39 * nlmsg_get_pos() return current position in message
40 * nlmsg_trim() trim part of message
41 * nlmsg_cancel() cancel message construction
42 * nlmsg_free() free a netlink message
43 *
44 * Message Sending:
45 * nlmsg_multicast() multicast message to several groups
46 * nlmsg_unicast() unicast a message to a single socket
47 * nlmsg_notify() send notification message
48 *
49 * Message Length Calculations:
50 * nlmsg_msg_size(payload) length of message w/o padding
51 * nlmsg_total_size(payload) length of message w/ padding
52 * nlmsg_padlen(payload) length of padding at tail
53 *
54 * Message Payload Access:
55 * nlmsg_data(nlh) head of message payload
56 * nlmsg_len(nlh) length of message payload
57 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
58 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
59 *
60 * Message Parsing:
61 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
62 * nlmsg_next(nlh, remaining) get next netlink message
63 * nlmsg_parse() parse attributes of a message
64 * nlmsg_find_attr() find an attribute in a message
65 * nlmsg_for_each_msg() loop over all messages
66 * nlmsg_validate() validate netlink message incl. attrs
67 * nlmsg_for_each_attr() loop over all attributes
68 *
69 * Misc:
70 * nlmsg_report() report back to application?
71 *
72 * ------------------------------------------------------------------------
73 * Attributes Interface
74 * ------------------------------------------------------------------------
75 *
76 * Attribute Format:
77 * <------- nla_total_size(payload) ------->
78 * <---- nla_attr_size(payload) ----->
79 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
80 * | Header | Pad | Payload | Pad | Header
81 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
82 * <- nla_len(nla) -> ^
83 * nla_data(nla)----^ |
84 * nla_next(nla)-----------------------------'
85 *
86 * Data Structures:
87 * struct nlattr netlink attribute header
88 *
89 * Attribute Construction:
90 * nla_reserve(skb, type, len) reserve room for an attribute
91 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
92 * nla_put(skb, type, len, data) add attribute to skb
93 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
94 * nla_append(skb, len, data) append data to skb
95 *
96 * Attribute Construction for Basic Types:
97 * nla_put_u8(skb, type, value) add u8 attribute to skb
98 * nla_put_u16(skb, type, value) add u16 attribute to skb
99 * nla_put_u32(skb, type, value) add u32 attribute to skb
100 * nla_put_u64(skb, type, value) add u64 attribute to skb
101 * nla_put_string(skb, type, str) add string attribute to skb
102 * nla_put_flag(skb, type) add flag attribute to skb
103 * nla_put_msecs(skb, type, jiffies) add msecs attribute to skb
104 *
105 * Exceptions Based Attribute Construction:
106 * NLA_PUT(skb, type, len, data) add attribute to skb
107 * NLA_PUT_U8(skb, type, value) add u8 attribute to skb
108 * NLA_PUT_U16(skb, type, value) add u16 attribute to skb
109 * NLA_PUT_U32(skb, type, value) add u32 attribute to skb
110 * NLA_PUT_U64(skb, type, value) add u64 attribute to skb
111 * NLA_PUT_STRING(skb, type, str) add string attribute to skb
112 * NLA_PUT_FLAG(skb, type) add flag attribute to skb
113 * NLA_PUT_MSECS(skb, type, jiffies) add msecs attribute to skb
114 *
115 * The meaning of these functions is equal to their lower case
116 * variants but they jump to the label nla_put_failure in case
117 * of a failure.
118 *
119 * Nested Attributes Construction:
120 * nla_nest_start(skb, type) start a nested attribute
121 * nla_nest_end(skb, nla) finalize a nested attribute
122 * nla_nest_cancel(skb, nla) cancel nested attribute construction
123 *
124 * Attribute Length Calculations:
125 * nla_attr_size(payload) length of attribute w/o padding
126 * nla_total_size(payload) length of attribute w/ padding
127 * nla_padlen(payload) length of padding
128 *
129 * Attribute Payload Access:
130 * nla_data(nla) head of attribute payload
131 * nla_len(nla) length of attribute payload
132 *
133 * Attribute Payload Access for Basic Types:
134 * nla_get_u8(nla) get payload for a u8 attribute
135 * nla_get_u16(nla) get payload for a u16 attribute
136 * nla_get_u32(nla) get payload for a u32 attribute
137 * nla_get_u64(nla) get payload for a u64 attribute
138 * nla_get_flag(nla) return 1 if flag is true
139 * nla_get_msecs(nla) get payload for a msecs attribute
140 *
141 * Attribute Misc:
142 * nla_memcpy(dest, nla, count) copy attribute into memory
143 * nla_memcmp(nla, data, size) compare attribute with memory area
144 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
145 * nla_strcmp(nla, str) compare attribute with string
146 *
147 * Attribute Parsing:
148 * nla_ok(nla, remaining) does nla fit into remaining bytes?
149 * nla_next(nla, remaining) get next netlink attribute
150 * nla_validate() validate a stream of attributes
151 * nla_validate_nested() validate a stream of nested attributes
152 * nla_find() find attribute in stream of attributes
153 * nla_find_nested() find attribute in nested attributes
154 * nla_parse() parse and validate stream of attrs
155 * nla_parse_nested() parse nested attribuets
156 * nla_for_each_attr() loop over all attributes
157 * nla_for_each_nested() loop over the nested attributes
158 *=========================================================================
159 */
160
161 /**
162 * Standard attribute types to specify validation policy
163 */
164enum {
165 NLA_UNSPEC,
166 NLA_U8,
167 NLA_U16,
168 NLA_U32,
169 NLA_U64,
170 NLA_STRING,
171 NLA_FLAG,
172 NLA_MSECS,
173 NLA_NESTED,
174 NLA_NESTED_COMPAT,
175 NLA_NUL_STRING,
176 NLA_BINARY,
177 __NLA_TYPE_MAX,
178};
179
180#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
181
182/**
183 * struct nla_policy - attribute validation policy
184 * @type: Type of attribute or NLA_UNSPEC
185 * @len: Type specific length of payload
186 *
187 * Policies are defined as arrays of this struct, the array must be
188 * accessible by attribute type up to the highest identifier to be expected.
189 *
190 * Meaning of `len' field:
191 * NLA_STRING Maximum length of string
192 * NLA_NUL_STRING Maximum length of string (excluding NUL)
193 * NLA_FLAG Unused
194 * NLA_BINARY Maximum length of attribute payload
195 * NLA_NESTED_COMPAT Exact length of structure payload
196 * All other Exact length of attribute payload
197 *
198 * Example:
199 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
200 * [ATTR_FOO] = { .type = NLA_U16 },
201 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
202 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
203 * };
204 */
205struct nla_policy {
206 u16 type;
207 u16 len;
208};
209
210/**
211 * struct nl_info - netlink source information
212 * @nlh: Netlink message header of original request
213 * @pid: Netlink PID of requesting application
214 */
215struct nl_info {
216 struct nlmsghdr *nlh;
217 struct net *nl_net;
218 u32 pid;
219};
220
221extern int netlink_rcv_skb(struct sk_buff *skb,
222 int (*cb)(struct sk_buff *,
223 struct nlmsghdr *));
224extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb,
225 u32 pid, unsigned int group, int report,
226 gfp_t flags);
227
228extern int nla_validate(const struct nlattr *head,
229 int len, int maxtype,
230 const struct nla_policy *policy);
231extern int nla_parse(struct nlattr **tb, int maxtype,
232 const struct nlattr *head, int len,
233 const struct nla_policy *policy);
234extern int nla_policy_len(const struct nla_policy *, int);
235extern struct nlattr * nla_find(const struct nlattr *head,
236 int len, int attrtype);
237extern size_t nla_strlcpy(char *dst, const struct nlattr *nla,
238 size_t dstsize);
239extern int nla_memcpy(void *dest, const struct nlattr *src, int count);
240extern int nla_memcmp(const struct nlattr *nla, const void *data,
241 size_t size);
242extern int nla_strcmp(const struct nlattr *nla, const char *str);
243extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype,
244 int attrlen);
245extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
246extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype,
247 int attrlen);
248extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
249extern void __nla_put(struct sk_buff *skb, int attrtype,
250 int attrlen, const void *data);
251extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen,
252 const void *data);
253extern int nla_put(struct sk_buff *skb, int attrtype,
254 int attrlen, const void *data);
255extern int nla_put_nohdr(struct sk_buff *skb, int attrlen,
256 const void *data);
257extern int nla_append(struct sk_buff *skb, int attrlen,
258 const void *data);
259
260/**************************************************************************
261 * Netlink Messages
262 **************************************************************************/
263
264/**
265 * nlmsg_msg_size - length of netlink message not including padding
266 * @payload: length of message payload
267 */
268static inline int nlmsg_msg_size(int payload)
269{
270 return NLMSG_HDRLEN + payload;
271}
272
273/**
274 * nlmsg_total_size - length of netlink message including padding
275 * @payload: length of message payload
276 */
277static inline int nlmsg_total_size(int payload)
278{
279 return NLMSG_ALIGN(nlmsg_msg_size(payload));
280}
281
282/**
283 * nlmsg_padlen - length of padding at the message's tail
284 * @payload: length of message payload
285 */
286static inline int nlmsg_padlen(int payload)
287{
288 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
289}
290
291/**
292 * nlmsg_data - head of message payload
293 * @nlh: netlink message header
294 */
295static inline void *nlmsg_data(const struct nlmsghdr *nlh)
296{
297 return (unsigned char *) nlh + NLMSG_HDRLEN;
298}
299
300/**
301 * nlmsg_len - length of message payload
302 * @nlh: netlink message header
303 */
304static inline int nlmsg_len(const struct nlmsghdr *nlh)
305{
306 return nlh->nlmsg_len - NLMSG_HDRLEN;
307}
308
309/**
310 * nlmsg_attrdata - head of attributes data
311 * @nlh: netlink message header
312 * @hdrlen: length of family specific header
313 */
314static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
315 int hdrlen)
316{
317 unsigned char *data = nlmsg_data(nlh);
318 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
319}
320
321/**
322 * nlmsg_attrlen - length of attributes data
323 * @nlh: netlink message header
324 * @hdrlen: length of family specific header
325 */
326static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
327{
328 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
329}
330
331/**
332 * nlmsg_ok - check if the netlink message fits into the remaining bytes
333 * @nlh: netlink message header
334 * @remaining: number of bytes remaining in message stream
335 */
336static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
337{
338 return (remaining >= (int) sizeof(struct nlmsghdr) &&
339 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
340 nlh->nlmsg_len <= remaining);
341}
342
343/**
344 * nlmsg_next - next netlink message in message stream
345 * @nlh: netlink message header
346 * @remaining: number of bytes remaining in message stream
347 *
348 * Returns the next netlink message in the message stream and
349 * decrements remaining by the size of the current message.
350 */
351static inline struct nlmsghdr *
352nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
353{
354 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
355
356 *remaining -= totlen;
357
358 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
359}
360
361/**
362 * nlmsg_parse - parse attributes of a netlink message
363 * @nlh: netlink message header
364 * @hdrlen: length of family specific header
365 * @tb: destination array with maxtype+1 elements
366 * @maxtype: maximum attribute type to be expected
367 * @policy: validation policy
368 *
369 * See nla_parse()
370 */
371static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
372 struct nlattr *tb[], int maxtype,
373 const struct nla_policy *policy)
374{
375 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
376 return -EINVAL;
377
378 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
379 nlmsg_attrlen(nlh, hdrlen), policy);
380}
381
382/**
383 * nlmsg_find_attr - find a specific attribute in a netlink message
384 * @nlh: netlink message header
385 * @hdrlen: length of familiy specific header
386 * @attrtype: type of attribute to look for
387 *
388 * Returns the first attribute which matches the specified type.
389 */
390static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
391 int hdrlen, int attrtype)
392{
393 return nla_find(nlmsg_attrdata(nlh, hdrlen),
394 nlmsg_attrlen(nlh, hdrlen), attrtype);
395}
396
397/**
398 * nlmsg_validate - validate a netlink message including attributes
399 * @nlh: netlinket message header
400 * @hdrlen: length of familiy specific header
401 * @maxtype: maximum attribute type to be expected
402 * @policy: validation policy
403 */
404static inline int nlmsg_validate(const struct nlmsghdr *nlh,
405 int hdrlen, int maxtype,
406 const struct nla_policy *policy)
407{
408 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
409 return -EINVAL;
410
411 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
412 nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
413}
414
415/**
416 * nlmsg_report - need to report back to application?
417 * @nlh: netlink message header
418 *
419 * Returns 1 if a report back to the application is requested.
420 */
421static inline int nlmsg_report(const struct nlmsghdr *nlh)
422{
423 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
424}
425
426/**
427 * nlmsg_for_each_attr - iterate over a stream of attributes
428 * @pos: loop counter, set to current attribute
429 * @nlh: netlink message header
430 * @hdrlen: length of familiy specific header
431 * @rem: initialized to len, holds bytes currently remaining in stream
432 */
433#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
434 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
435 nlmsg_attrlen(nlh, hdrlen), rem)
436
437#if 0
438/* FIXME: Enable once all users have been converted */
439
440/**
441 * __nlmsg_put - Add a new netlink message to an skb
442 * @skb: socket buffer to store message in
443 * @pid: netlink process id
444 * @seq: sequence number of message
445 * @type: message type
446 * @payload: length of message payload
447 * @flags: message flags
448 *
449 * The caller is responsible to ensure that the skb provides enough
450 * tailroom for both the netlink header and payload.
451 */
452static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid,
453 u32 seq, int type, int payload,
454 int flags)
455{
456 struct nlmsghdr *nlh;
457
458 nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload));
459 nlh->nlmsg_type = type;
460 nlh->nlmsg_len = nlmsg_msg_size(payload);
461 nlh->nlmsg_flags = flags;
462 nlh->nlmsg_pid = pid;
463 nlh->nlmsg_seq = seq;
464
465 memset((unsigned char *) nlmsg_data(nlh) + payload, 0,
466 nlmsg_padlen(payload));
467
468 return nlh;
469}
470#endif
471
472/**
473 * nlmsg_put - Add a new netlink message to an skb
474 * @skb: socket buffer to store message in
475 * @pid: netlink process id
476 * @seq: sequence number of message
477 * @type: message type
478 * @payload: length of message payload
479 * @flags: message flags
480 *
481 * Returns NULL if the tailroom of the skb is insufficient to store
482 * the message header and payload.
483 */
484static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
485 int type, int payload, int flags)
486{
487 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
488 return NULL;
489
490 return __nlmsg_put(skb, pid, seq, type, payload, flags);
491}
492
493/**
494 * nlmsg_put_answer - Add a new callback based netlink message to an skb
495 * @skb: socket buffer to store message in
496 * @cb: netlink callback
497 * @type: message type
498 * @payload: length of message payload
499 * @flags: message flags
500 *
501 * Returns NULL if the tailroom of the skb is insufficient to store
502 * the message header and payload.
503 */
504static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
505 struct netlink_callback *cb,
506 int type, int payload,
507 int flags)
508{
509 return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
510 type, payload, flags);
511}
512
513/**
514 * nlmsg_new - Allocate a new netlink message
515 * @payload: size of the message payload
516 * @flags: the type of memory to allocate.
517 *
518 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
519 * and a good default is needed.
520 */
521static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
522{
523 return alloc_skb(nlmsg_total_size(payload), flags);
524}
525
526/**
527 * nlmsg_end - Finalize a netlink message
528 * @skb: socket buffer the message is stored in
529 * @nlh: netlink message header
530 *
531 * Corrects the netlink message header to include the appeneded
532 * attributes. Only necessary if attributes have been added to
533 * the message.
534 *
535 * Returns the total data length of the skb.
536 */
537static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
538{
539 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
540
541 return skb->len;
542}
543
544/**
545 * nlmsg_get_pos - return current position in netlink message
546 * @skb: socket buffer the message is stored in
547 *
548 * Returns a pointer to the current tail of the message.
549 */
550static inline void *nlmsg_get_pos(struct sk_buff *skb)
551{
552 return skb_tail_pointer(skb);
553}
554
555/**
556 * nlmsg_trim - Trim message to a mark
557 * @skb: socket buffer the message is stored in
558 * @mark: mark to trim to
559 *
560 * Trims the message to the provided mark.
561 */
562static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
563{
564 if (mark)
565 skb_trim(skb, (unsigned char *) mark - skb->data);
566}
567
568/**
569 * nlmsg_cancel - Cancel construction of a netlink message
570 * @skb: socket buffer the message is stored in
571 * @nlh: netlink message header
572 *
573 * Removes the complete netlink message including all
574 * attributes from the socket buffer again.
575 */
576static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
577{
578 nlmsg_trim(skb, nlh);
579}
580
581/**
582 * nlmsg_free - free a netlink message
583 * @skb: socket buffer of netlink message
584 */
585static inline void nlmsg_free(struct sk_buff *skb)
586{
587 kfree_skb(skb);
588}
589
590/**
591 * nlmsg_multicast - multicast a netlink message
592 * @sk: netlink socket to spread messages to
593 * @skb: netlink message as socket buffer
594 * @pid: own netlink pid to avoid sending to yourself
595 * @group: multicast group id
596 * @flags: allocation flags
597 */
598static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
599 u32 pid, unsigned int group, gfp_t flags)
600{
601 int err;
602
603 NETLINK_CB(skb).dst_group = group;
604
605 err = netlink_broadcast(sk, skb, pid, group, flags);
606 if (err > 0)
607 err = 0;
608
609 return err;
610}
611
612/**
613 * nlmsg_unicast - unicast a netlink message
614 * @sk: netlink socket to spread message to
615 * @skb: netlink message as socket buffer
616 * @pid: netlink pid of the destination socket
617 */
618static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid)
619{
620 int err;
621
622 err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT);
623 if (err > 0)
624 err = 0;
625
626 return err;
627}
628
629/**
630 * nlmsg_for_each_msg - iterate over a stream of messages
631 * @pos: loop counter, set to current message
632 * @head: head of message stream
633 * @len: length of message stream
634 * @rem: initialized to len, holds bytes currently remaining in stream
635 */
636#define nlmsg_for_each_msg(pos, head, len, rem) \
637 for (pos = head, rem = len; \
638 nlmsg_ok(pos, rem); \
639 pos = nlmsg_next(pos, &(rem)))
640
641/**
642 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
643 * @cb: netlink callback structure that stores the sequence number
644 * @nlh: netlink message header to write the flag to
645 *
646 * This function checks if the sequence (generation) number changed during dump
647 * and if it did, advertises it in the netlink message header.
648 *
649 * The correct way to use it is to set cb->seq to the generation counter when
650 * all locks for dumping have been acquired, and then call this function for
651 * each message that is generated.
652 *
653 * Note that due to initialisation concerns, 0 is an invalid sequence number
654 * and must not be used by code that uses this functionality.
655 */
656static inline void
657nl_dump_check_consistent(struct netlink_callback *cb,
658 struct nlmsghdr *nlh)
659{
660 if (cb->prev_seq && cb->seq != cb->prev_seq)
661 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
662 cb->prev_seq = cb->seq;
663}
664
665/**************************************************************************
666 * Netlink Attributes
667 **************************************************************************/
668
669/**
670 * nla_attr_size - length of attribute not including padding
671 * @payload: length of payload
672 */
673static inline int nla_attr_size(int payload)
674{
675 return NLA_HDRLEN + payload;
676}
677
678/**
679 * nla_total_size - total length of attribute including padding
680 * @payload: length of payload
681 */
682static inline int nla_total_size(int payload)
683{
684 return NLA_ALIGN(nla_attr_size(payload));
685}
686
687/**
688 * nla_padlen - length of padding at the tail of attribute
689 * @payload: length of payload
690 */
691static inline int nla_padlen(int payload)
692{
693 return nla_total_size(payload) - nla_attr_size(payload);
694}
695
696/**
697 * nla_type - attribute type
698 * @nla: netlink attribute
699 */
700static inline int nla_type(const struct nlattr *nla)
701{
702 return nla->nla_type & NLA_TYPE_MASK;
703}
704
705/**
706 * nla_data - head of payload
707 * @nla: netlink attribute
708 */
709static inline void *nla_data(const struct nlattr *nla)
710{
711 return (char *) nla + NLA_HDRLEN;
712}
713
714/**
715 * nla_len - length of payload
716 * @nla: netlink attribute
717 */
718static inline int nla_len(const struct nlattr *nla)
719{
720 return nla->nla_len - NLA_HDRLEN;
721}
722
723/**
724 * nla_ok - check if the netlink attribute fits into the remaining bytes
725 * @nla: netlink attribute
726 * @remaining: number of bytes remaining in attribute stream
727 */
728static inline int nla_ok(const struct nlattr *nla, int remaining)
729{
730 return remaining >= (int) sizeof(*nla) &&
731 nla->nla_len >= sizeof(*nla) &&
732 nla->nla_len <= remaining;
733}
734
735/**
736 * nla_next - next netlink attribute in attribute stream
737 * @nla: netlink attribute
738 * @remaining: number of bytes remaining in attribute stream
739 *
740 * Returns the next netlink attribute in the attribute stream and
741 * decrements remaining by the size of the current attribute.
742 */
743static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
744{
745 int totlen = NLA_ALIGN(nla->nla_len);
746
747 *remaining -= totlen;
748 return (struct nlattr *) ((char *) nla + totlen);
749}
750
751/**
752 * nla_find_nested - find attribute in a set of nested attributes
753 * @nla: attribute containing the nested attributes
754 * @attrtype: type of attribute to look for
755 *
756 * Returns the first attribute which matches the specified type.
757 */
758static inline struct nlattr *
759nla_find_nested(const struct nlattr *nla, int attrtype)
760{
761 return nla_find(nla_data(nla), nla_len(nla), attrtype);
762}
763
764/**
765 * nla_parse_nested - parse nested attributes
766 * @tb: destination array with maxtype+1 elements
767 * @maxtype: maximum attribute type to be expected
768 * @nla: attribute containing the nested attributes
769 * @policy: validation policy
770 *
771 * See nla_parse()
772 */
773static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
774 const struct nlattr *nla,
775 const struct nla_policy *policy)
776{
777 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
778}
779
780/**
781 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
782 * @skb: socket buffer to add attribute to
783 * @attrtype: attribute type
784 * @value: numeric value
785 */
786static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
787{
788 return nla_put(skb, attrtype, sizeof(u8), &value);
789}
790
791/**
792 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
793 * @skb: socket buffer to add attribute to
794 * @attrtype: attribute type
795 * @value: numeric value
796 */
797static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
798{
799 return nla_put(skb, attrtype, sizeof(u16), &value);
800}
801
802/**
803 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
804 * @skb: socket buffer to add attribute to
805 * @attrtype: attribute type
806 * @value: numeric value
807 */
808static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
809{
810 return nla_put(skb, attrtype, sizeof(u32), &value);
811}
812
813/**
814 * nla_put_64 - Add a u64 netlink attribute to a socket buffer
815 * @skb: socket buffer to add attribute to
816 * @attrtype: attribute type
817 * @value: numeric value
818 */
819static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
820{
821 return nla_put(skb, attrtype, sizeof(u64), &value);
822}
823
824/**
825 * nla_put_string - Add a string netlink attribute to a socket buffer
826 * @skb: socket buffer to add attribute to
827 * @attrtype: attribute type
828 * @str: NUL terminated string
829 */
830static inline int nla_put_string(struct sk_buff *skb, int attrtype,
831 const char *str)
832{
833 return nla_put(skb, attrtype, strlen(str) + 1, str);
834}
835
836/**
837 * nla_put_flag - Add a flag netlink attribute to a socket buffer
838 * @skb: socket buffer to add attribute to
839 * @attrtype: attribute type
840 */
841static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
842{
843 return nla_put(skb, attrtype, 0, NULL);
844}
845
846/**
847 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer
848 * @skb: socket buffer to add attribute to
849 * @attrtype: attribute type
850 * @jiffies: number of msecs in jiffies
851 */
852static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
853 unsigned long jiffies)
854{
855 u64 tmp = jiffies_to_msecs(jiffies);
856 return nla_put(skb, attrtype, sizeof(u64), &tmp);
857}
858
859#define NLA_PUT(skb, attrtype, attrlen, data) \
860 do { \
861 if (unlikely(nla_put(skb, attrtype, attrlen, data) < 0)) \
862 goto nla_put_failure; \
863 } while(0)
864
865#define NLA_PUT_TYPE(skb, type, attrtype, value) \
866 do { \
867 type __tmp = value; \
868 NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \
869 } while(0)
870
871#define NLA_PUT_U8(skb, attrtype, value) \
872 NLA_PUT_TYPE(skb, u8, attrtype, value)
873
874#define NLA_PUT_U16(skb, attrtype, value) \
875 NLA_PUT_TYPE(skb, u16, attrtype, value)
876
877#define NLA_PUT_LE16(skb, attrtype, value) \
878 NLA_PUT_TYPE(skb, __le16, attrtype, value)
879
880#define NLA_PUT_BE16(skb, attrtype, value) \
881 NLA_PUT_TYPE(skb, __be16, attrtype, value)
882
883#define NLA_PUT_NET16(skb, attrtype, value) \
884 NLA_PUT_BE16(skb, attrtype | NLA_F_NET_BYTEORDER, value)
885
886#define NLA_PUT_U32(skb, attrtype, value) \
887 NLA_PUT_TYPE(skb, u32, attrtype, value)
888
889#define NLA_PUT_BE32(skb, attrtype, value) \
890 NLA_PUT_TYPE(skb, __be32, attrtype, value)
891
892#define NLA_PUT_NET32(skb, attrtype, value) \
893 NLA_PUT_BE32(skb, attrtype | NLA_F_NET_BYTEORDER, value)
894
895#define NLA_PUT_U64(skb, attrtype, value) \
896 NLA_PUT_TYPE(skb, u64, attrtype, value)
897
898#define NLA_PUT_BE64(skb, attrtype, value) \
899 NLA_PUT_TYPE(skb, __be64, attrtype, value)
900
901#define NLA_PUT_NET64(skb, attrtype, value) \
902 NLA_PUT_BE64(skb, attrtype | NLA_F_NET_BYTEORDER, value)
903
904#define NLA_PUT_STRING(skb, attrtype, value) \
905 NLA_PUT(skb, attrtype, strlen(value) + 1, value)
906
907#define NLA_PUT_FLAG(skb, attrtype) \
908 NLA_PUT(skb, attrtype, 0, NULL)
909
910#define NLA_PUT_MSECS(skb, attrtype, jiffies) \
911 NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies))
912
913/**
914 * nla_get_u32 - return payload of u32 attribute
915 * @nla: u32 netlink attribute
916 */
917static inline u32 nla_get_u32(const struct nlattr *nla)
918{
919 return *(u32 *) nla_data(nla);
920}
921
922/**
923 * nla_get_be32 - return payload of __be32 attribute
924 * @nla: __be32 netlink attribute
925 */
926static inline __be32 nla_get_be32(const struct nlattr *nla)
927{
928 return *(__be32 *) nla_data(nla);
929}
930
931/**
932 * nla_get_u16 - return payload of u16 attribute
933 * @nla: u16 netlink attribute
934 */
935static inline u16 nla_get_u16(const struct nlattr *nla)
936{
937 return *(u16 *) nla_data(nla);
938}
939
940/**
941 * nla_get_be16 - return payload of __be16 attribute
942 * @nla: __be16 netlink attribute
943 */
944static inline __be16 nla_get_be16(const struct nlattr *nla)
945{
946 return *(__be16 *) nla_data(nla);
947}
948
949/**
950 * nla_get_le16 - return payload of __le16 attribute
951 * @nla: __le16 netlink attribute
952 */
953static inline __le16 nla_get_le16(const struct nlattr *nla)
954{
955 return *(__le16 *) nla_data(nla);
956}
957
958/**
959 * nla_get_u8 - return payload of u8 attribute
960 * @nla: u8 netlink attribute
961 */
962static inline u8 nla_get_u8(const struct nlattr *nla)
963{
964 return *(u8 *) nla_data(nla);
965}
966
967/**
968 * nla_get_u64 - return payload of u64 attribute
969 * @nla: u64 netlink attribute
970 */
971static inline u64 nla_get_u64(const struct nlattr *nla)
972{
973 u64 tmp;
974
975 nla_memcpy(&tmp, nla, sizeof(tmp));
976
977 return tmp;
978}
979
980/**
981 * nla_get_be64 - return payload of __be64 attribute
982 * @nla: __be64 netlink attribute
983 */
984static inline __be64 nla_get_be64(const struct nlattr *nla)
985{
986 __be64 tmp;
987
988 nla_memcpy(&tmp, nla, sizeof(tmp));
989
990 return tmp;
991}
992
993/**
994 * nla_get_flag - return payload of flag attribute
995 * @nla: flag netlink attribute
996 */
997static inline int nla_get_flag(const struct nlattr *nla)
998{
999 return !!nla;
1000}
1001
1002/**
1003 * nla_get_msecs - return payload of msecs attribute
1004 * @nla: msecs netlink attribute
1005 *
1006 * Returns the number of milliseconds in jiffies.
1007 */
1008static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1009{
1010 u64 msecs = nla_get_u64(nla);
1011
1012 return msecs_to_jiffies((unsigned long) msecs);
1013}
1014
1015/**
1016 * nla_nest_start - Start a new level of nested attributes
1017 * @skb: socket buffer to add attributes to
1018 * @attrtype: attribute type of container
1019 *
1020 * Returns the container attribute
1021 */
1022static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1023{
1024 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1025
1026 if (nla_put(skb, attrtype, 0, NULL) < 0)
1027 return NULL;
1028
1029 return start;
1030}
1031
1032/**
1033 * nla_nest_end - Finalize nesting of attributes
1034 * @skb: socket buffer the attributes are stored in
1035 * @start: container attribute
1036 *
1037 * Corrects the container attribute header to include the all
1038 * appeneded attributes.
1039 *
1040 * Returns the total data length of the skb.
1041 */
1042static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1043{
1044 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1045 return skb->len;
1046}
1047
1048/**
1049 * nla_nest_cancel - Cancel nesting of attributes
1050 * @skb: socket buffer the message is stored in
1051 * @start: container attribute
1052 *
1053 * Removes the container attribute and including all nested
1054 * attributes. Returns -EMSGSIZE
1055 */
1056static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1057{
1058 nlmsg_trim(skb, start);
1059}
1060
1061/**
1062 * nla_validate_nested - Validate a stream of nested attributes
1063 * @start: container attribute
1064 * @maxtype: maximum attribute type to be expected
1065 * @policy: validation policy
1066 *
1067 * Validates all attributes in the nested attribute stream against the
1068 * specified policy. Attributes with a type exceeding maxtype will be
1069 * ignored. See documenation of struct nla_policy for more details.
1070 *
1071 * Returns 0 on success or a negative error code.
1072 */
1073static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
1074 const struct nla_policy *policy)
1075{
1076 return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
1077}
1078
1079/**
1080 * nla_for_each_attr - iterate over a stream of attributes
1081 * @pos: loop counter, set to current attribute
1082 * @head: head of attribute stream
1083 * @len: length of attribute stream
1084 * @rem: initialized to len, holds bytes currently remaining in stream
1085 */
1086#define nla_for_each_attr(pos, head, len, rem) \
1087 for (pos = head, rem = len; \
1088 nla_ok(pos, rem); \
1089 pos = nla_next(pos, &(rem)))
1090
1091/**
1092 * nla_for_each_nested - iterate over nested attributes
1093 * @pos: loop counter, set to current attribute
1094 * @nla: attribute containing the nested attributes
1095 * @rem: initialized to len, holds bytes currently remaining in stream
1096 */
1097#define nla_for_each_nested(pos, nla, rem) \
1098 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1099
1100#endif
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __NET_NETLINK_H
3#define __NET_NETLINK_H
4
5#include <linux/types.h>
6#include <linux/netlink.h>
7#include <linux/jiffies.h>
8#include <linux/in6.h>
9
10/* ========================================================================
11 * Netlink Messages and Attributes Interface (As Seen On TV)
12 * ------------------------------------------------------------------------
13 * Messages Interface
14 * ------------------------------------------------------------------------
15 *
16 * Message Format:
17 * <--- nlmsg_total_size(payload) --->
18 * <-- nlmsg_msg_size(payload) ->
19 * +----------+- - -+-------------+- - -+-------- - -
20 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr
21 * +----------+- - -+-------------+- - -+-------- - -
22 * nlmsg_data(nlh)---^ ^
23 * nlmsg_next(nlh)-----------------------+
24 *
25 * Payload Format:
26 * <---------------------- nlmsg_len(nlh) --------------------->
27 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
28 * +----------------------+- - -+--------------------------------+
29 * | Family Header | Pad | Attributes |
30 * +----------------------+- - -+--------------------------------+
31 * nlmsg_attrdata(nlh, hdrlen)---^
32 *
33 * Data Structures:
34 * struct nlmsghdr netlink message header
35 *
36 * Message Construction:
37 * nlmsg_new() create a new netlink message
38 * nlmsg_put() add a netlink message to an skb
39 * nlmsg_put_answer() callback based nlmsg_put()
40 * nlmsg_end() finalize netlink message
41 * nlmsg_get_pos() return current position in message
42 * nlmsg_trim() trim part of message
43 * nlmsg_cancel() cancel message construction
44 * nlmsg_free() free a netlink message
45 *
46 * Message Sending:
47 * nlmsg_multicast() multicast message to several groups
48 * nlmsg_unicast() unicast a message to a single socket
49 * nlmsg_notify() send notification message
50 *
51 * Message Length Calculations:
52 * nlmsg_msg_size(payload) length of message w/o padding
53 * nlmsg_total_size(payload) length of message w/ padding
54 * nlmsg_padlen(payload) length of padding at tail
55 *
56 * Message Payload Access:
57 * nlmsg_data(nlh) head of message payload
58 * nlmsg_len(nlh) length of message payload
59 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
60 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
61 *
62 * Message Parsing:
63 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
64 * nlmsg_next(nlh, remaining) get next netlink message
65 * nlmsg_parse() parse attributes of a message
66 * nlmsg_find_attr() find an attribute in a message
67 * nlmsg_for_each_msg() loop over all messages
68 * nlmsg_validate() validate netlink message incl. attrs
69 * nlmsg_for_each_attr() loop over all attributes
70 *
71 * Misc:
72 * nlmsg_report() report back to application?
73 *
74 * ------------------------------------------------------------------------
75 * Attributes Interface
76 * ------------------------------------------------------------------------
77 *
78 * Attribute Format:
79 * <------- nla_total_size(payload) ------->
80 * <---- nla_attr_size(payload) ----->
81 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
82 * | Header | Pad | Payload | Pad | Header
83 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
84 * <- nla_len(nla) -> ^
85 * nla_data(nla)----^ |
86 * nla_next(nla)-----------------------------'
87 *
88 * Data Structures:
89 * struct nlattr netlink attribute header
90 *
91 * Attribute Construction:
92 * nla_reserve(skb, type, len) reserve room for an attribute
93 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
94 * nla_put(skb, type, len, data) add attribute to skb
95 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
96 * nla_append(skb, len, data) append data to skb
97 *
98 * Attribute Construction for Basic Types:
99 * nla_put_u8(skb, type, value) add u8 attribute to skb
100 * nla_put_u16(skb, type, value) add u16 attribute to skb
101 * nla_put_u32(skb, type, value) add u32 attribute to skb
102 * nla_put_u64_64bit(skb, type,
103 * value, padattr) add u64 attribute to skb
104 * nla_put_s8(skb, type, value) add s8 attribute to skb
105 * nla_put_s16(skb, type, value) add s16 attribute to skb
106 * nla_put_s32(skb, type, value) add s32 attribute to skb
107 * nla_put_s64(skb, type, value,
108 * padattr) add s64 attribute to skb
109 * nla_put_string(skb, type, str) add string attribute to skb
110 * nla_put_flag(skb, type) add flag attribute to skb
111 * nla_put_msecs(skb, type, jiffies,
112 * padattr) add msecs attribute to skb
113 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb
114 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb
115 *
116 * Nested Attributes Construction:
117 * nla_nest_start(skb, type) start a nested attribute
118 * nla_nest_end(skb, nla) finalize a nested attribute
119 * nla_nest_cancel(skb, nla) cancel nested attribute construction
120 *
121 * Attribute Length Calculations:
122 * nla_attr_size(payload) length of attribute w/o padding
123 * nla_total_size(payload) length of attribute w/ padding
124 * nla_padlen(payload) length of padding
125 *
126 * Attribute Payload Access:
127 * nla_data(nla) head of attribute payload
128 * nla_len(nla) length of attribute payload
129 *
130 * Attribute Payload Access for Basic Types:
131 * nla_get_u8(nla) get payload for a u8 attribute
132 * nla_get_u16(nla) get payload for a u16 attribute
133 * nla_get_u32(nla) get payload for a u32 attribute
134 * nla_get_u64(nla) get payload for a u64 attribute
135 * nla_get_s8(nla) get payload for a s8 attribute
136 * nla_get_s16(nla) get payload for a s16 attribute
137 * nla_get_s32(nla) get payload for a s32 attribute
138 * nla_get_s64(nla) get payload for a s64 attribute
139 * nla_get_flag(nla) return 1 if flag is true
140 * nla_get_msecs(nla) get payload for a msecs attribute
141 *
142 * Attribute Misc:
143 * nla_memcpy(dest, nla, count) copy attribute into memory
144 * nla_memcmp(nla, data, size) compare attribute with memory area
145 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
146 * nla_strcmp(nla, str) compare attribute with string
147 *
148 * Attribute Parsing:
149 * nla_ok(nla, remaining) does nla fit into remaining bytes?
150 * nla_next(nla, remaining) get next netlink attribute
151 * nla_validate() validate a stream of attributes
152 * nla_validate_nested() validate a stream of nested attributes
153 * nla_find() find attribute in stream of attributes
154 * nla_find_nested() find attribute in nested attributes
155 * nla_parse() parse and validate stream of attrs
156 * nla_parse_nested() parse nested attribuets
157 * nla_for_each_attr() loop over all attributes
158 * nla_for_each_nested() loop over the nested attributes
159 *=========================================================================
160 */
161
162 /**
163 * Standard attribute types to specify validation policy
164 */
165enum {
166 NLA_UNSPEC,
167 NLA_U8,
168 NLA_U16,
169 NLA_U32,
170 NLA_U64,
171 NLA_STRING,
172 NLA_FLAG,
173 NLA_MSECS,
174 NLA_NESTED,
175 NLA_NESTED_COMPAT,
176 NLA_NUL_STRING,
177 NLA_BINARY,
178 NLA_S8,
179 NLA_S16,
180 NLA_S32,
181 NLA_S64,
182 NLA_BITFIELD32,
183 __NLA_TYPE_MAX,
184};
185
186#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
187
188/**
189 * struct nla_policy - attribute validation policy
190 * @type: Type of attribute or NLA_UNSPEC
191 * @len: Type specific length of payload
192 *
193 * Policies are defined as arrays of this struct, the array must be
194 * accessible by attribute type up to the highest identifier to be expected.
195 *
196 * Meaning of `len' field:
197 * NLA_STRING Maximum length of string
198 * NLA_NUL_STRING Maximum length of string (excluding NUL)
199 * NLA_FLAG Unused
200 * NLA_BINARY Maximum length of attribute payload
201 * NLA_NESTED Don't use `len' field -- length verification is
202 * done by checking len of nested header (or empty)
203 * NLA_NESTED_COMPAT Minimum length of structure payload
204 * NLA_U8, NLA_U16,
205 * NLA_U32, NLA_U64,
206 * NLA_S8, NLA_S16,
207 * NLA_S32, NLA_S64,
208 * NLA_MSECS Leaving the length field zero will verify the
209 * given type fits, using it verifies minimum length
210 * just like "All other"
211 * NLA_BITFIELD32 A 32-bit bitmap/bitselector attribute
212 * All other Minimum length of attribute payload
213 *
214 * Example:
215 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
216 * [ATTR_FOO] = { .type = NLA_U16 },
217 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
218 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
219 * [ATTR_GOO] = { .type = NLA_BITFIELD32, .validation_data = &myvalidflags },
220 * };
221 */
222struct nla_policy {
223 u16 type;
224 u16 len;
225 void *validation_data;
226};
227
228/**
229 * struct nl_info - netlink source information
230 * @nlh: Netlink message header of original request
231 * @portid: Netlink PORTID of requesting application
232 */
233struct nl_info {
234 struct nlmsghdr *nlh;
235 struct net *nl_net;
236 u32 portid;
237 bool skip_notify;
238};
239
240int netlink_rcv_skb(struct sk_buff *skb,
241 int (*cb)(struct sk_buff *, struct nlmsghdr *,
242 struct netlink_ext_ack *));
243int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
244 unsigned int group, int report, gfp_t flags);
245
246int nla_validate(const struct nlattr *head, int len, int maxtype,
247 const struct nla_policy *policy,
248 struct netlink_ext_ack *extack);
249int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
250 int len, const struct nla_policy *policy,
251 struct netlink_ext_ack *extack);
252int nla_policy_len(const struct nla_policy *, int);
253struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
254size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
255char *nla_strdup(const struct nlattr *nla, gfp_t flags);
256int nla_memcpy(void *dest, const struct nlattr *src, int count);
257int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
258int nla_strcmp(const struct nlattr *nla, const char *str);
259struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
260struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
261 int attrlen, int padattr);
262void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
263struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
264struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
265 int attrlen, int padattr);
266void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
267void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
268 const void *data);
269void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
270 const void *data, int padattr);
271void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
272int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
273int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
274 const void *data, int padattr);
275int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
276int nla_append(struct sk_buff *skb, int attrlen, const void *data);
277
278/**************************************************************************
279 * Netlink Messages
280 **************************************************************************/
281
282/**
283 * nlmsg_msg_size - length of netlink message not including padding
284 * @payload: length of message payload
285 */
286static inline int nlmsg_msg_size(int payload)
287{
288 return NLMSG_HDRLEN + payload;
289}
290
291/**
292 * nlmsg_total_size - length of netlink message including padding
293 * @payload: length of message payload
294 */
295static inline int nlmsg_total_size(int payload)
296{
297 return NLMSG_ALIGN(nlmsg_msg_size(payload));
298}
299
300/**
301 * nlmsg_padlen - length of padding at the message's tail
302 * @payload: length of message payload
303 */
304static inline int nlmsg_padlen(int payload)
305{
306 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
307}
308
309/**
310 * nlmsg_data - head of message payload
311 * @nlh: netlink message header
312 */
313static inline void *nlmsg_data(const struct nlmsghdr *nlh)
314{
315 return (unsigned char *) nlh + NLMSG_HDRLEN;
316}
317
318/**
319 * nlmsg_len - length of message payload
320 * @nlh: netlink message header
321 */
322static inline int nlmsg_len(const struct nlmsghdr *nlh)
323{
324 return nlh->nlmsg_len - NLMSG_HDRLEN;
325}
326
327/**
328 * nlmsg_attrdata - head of attributes data
329 * @nlh: netlink message header
330 * @hdrlen: length of family specific header
331 */
332static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
333 int hdrlen)
334{
335 unsigned char *data = nlmsg_data(nlh);
336 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
337}
338
339/**
340 * nlmsg_attrlen - length of attributes data
341 * @nlh: netlink message header
342 * @hdrlen: length of family specific header
343 */
344static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
345{
346 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
347}
348
349/**
350 * nlmsg_ok - check if the netlink message fits into the remaining bytes
351 * @nlh: netlink message header
352 * @remaining: number of bytes remaining in message stream
353 */
354static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
355{
356 return (remaining >= (int) sizeof(struct nlmsghdr) &&
357 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
358 nlh->nlmsg_len <= remaining);
359}
360
361/**
362 * nlmsg_next - next netlink message in message stream
363 * @nlh: netlink message header
364 * @remaining: number of bytes remaining in message stream
365 *
366 * Returns the next netlink message in the message stream and
367 * decrements remaining by the size of the current message.
368 */
369static inline struct nlmsghdr *
370nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
371{
372 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
373
374 *remaining -= totlen;
375
376 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
377}
378
379/**
380 * nlmsg_parse - parse attributes of a netlink message
381 * @nlh: netlink message header
382 * @hdrlen: length of family specific header
383 * @tb: destination array with maxtype+1 elements
384 * @maxtype: maximum attribute type to be expected
385 * @policy: validation policy
386 * @extack: extended ACK report struct
387 *
388 * See nla_parse()
389 */
390static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
391 struct nlattr *tb[], int maxtype,
392 const struct nla_policy *policy,
393 struct netlink_ext_ack *extack)
394{
395 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
396 return -EINVAL;
397
398 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
399 nlmsg_attrlen(nlh, hdrlen), policy, extack);
400}
401
402/**
403 * nlmsg_find_attr - find a specific attribute in a netlink message
404 * @nlh: netlink message header
405 * @hdrlen: length of familiy specific header
406 * @attrtype: type of attribute to look for
407 *
408 * Returns the first attribute which matches the specified type.
409 */
410static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
411 int hdrlen, int attrtype)
412{
413 return nla_find(nlmsg_attrdata(nlh, hdrlen),
414 nlmsg_attrlen(nlh, hdrlen), attrtype);
415}
416
417/**
418 * nlmsg_validate - validate a netlink message including attributes
419 * @nlh: netlinket message header
420 * @hdrlen: length of familiy specific header
421 * @maxtype: maximum attribute type to be expected
422 * @policy: validation policy
423 * @extack: extended ACK report struct
424 */
425static inline int nlmsg_validate(const struct nlmsghdr *nlh,
426 int hdrlen, int maxtype,
427 const struct nla_policy *policy,
428 struct netlink_ext_ack *extack)
429{
430 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
431 return -EINVAL;
432
433 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
434 nlmsg_attrlen(nlh, hdrlen), maxtype, policy,
435 extack);
436}
437
438/**
439 * nlmsg_report - need to report back to application?
440 * @nlh: netlink message header
441 *
442 * Returns 1 if a report back to the application is requested.
443 */
444static inline int nlmsg_report(const struct nlmsghdr *nlh)
445{
446 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
447}
448
449/**
450 * nlmsg_for_each_attr - iterate over a stream of attributes
451 * @pos: loop counter, set to current attribute
452 * @nlh: netlink message header
453 * @hdrlen: length of familiy specific header
454 * @rem: initialized to len, holds bytes currently remaining in stream
455 */
456#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
457 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
458 nlmsg_attrlen(nlh, hdrlen), rem)
459
460/**
461 * nlmsg_put - Add a new netlink message to an skb
462 * @skb: socket buffer to store message in
463 * @portid: netlink PORTID of requesting application
464 * @seq: sequence number of message
465 * @type: message type
466 * @payload: length of message payload
467 * @flags: message flags
468 *
469 * Returns NULL if the tailroom of the skb is insufficient to store
470 * the message header and payload.
471 */
472static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
473 int type, int payload, int flags)
474{
475 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
476 return NULL;
477
478 return __nlmsg_put(skb, portid, seq, type, payload, flags);
479}
480
481/**
482 * nlmsg_put_answer - Add a new callback based netlink message to an skb
483 * @skb: socket buffer to store message in
484 * @cb: netlink callback
485 * @type: message type
486 * @payload: length of message payload
487 * @flags: message flags
488 *
489 * Returns NULL if the tailroom of the skb is insufficient to store
490 * the message header and payload.
491 */
492static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
493 struct netlink_callback *cb,
494 int type, int payload,
495 int flags)
496{
497 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
498 type, payload, flags);
499}
500
501/**
502 * nlmsg_new - Allocate a new netlink message
503 * @payload: size of the message payload
504 * @flags: the type of memory to allocate.
505 *
506 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
507 * and a good default is needed.
508 */
509static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
510{
511 return alloc_skb(nlmsg_total_size(payload), flags);
512}
513
514/**
515 * nlmsg_end - Finalize a netlink message
516 * @skb: socket buffer the message is stored in
517 * @nlh: netlink message header
518 *
519 * Corrects the netlink message header to include the appeneded
520 * attributes. Only necessary if attributes have been added to
521 * the message.
522 */
523static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
524{
525 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
526}
527
528/**
529 * nlmsg_get_pos - return current position in netlink message
530 * @skb: socket buffer the message is stored in
531 *
532 * Returns a pointer to the current tail of the message.
533 */
534static inline void *nlmsg_get_pos(struct sk_buff *skb)
535{
536 return skb_tail_pointer(skb);
537}
538
539/**
540 * nlmsg_trim - Trim message to a mark
541 * @skb: socket buffer the message is stored in
542 * @mark: mark to trim to
543 *
544 * Trims the message to the provided mark.
545 */
546static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
547{
548 if (mark) {
549 WARN_ON((unsigned char *) mark < skb->data);
550 skb_trim(skb, (unsigned char *) mark - skb->data);
551 }
552}
553
554/**
555 * nlmsg_cancel - Cancel construction of a netlink message
556 * @skb: socket buffer the message is stored in
557 * @nlh: netlink message header
558 *
559 * Removes the complete netlink message including all
560 * attributes from the socket buffer again.
561 */
562static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
563{
564 nlmsg_trim(skb, nlh);
565}
566
567/**
568 * nlmsg_free - free a netlink message
569 * @skb: socket buffer of netlink message
570 */
571static inline void nlmsg_free(struct sk_buff *skb)
572{
573 kfree_skb(skb);
574}
575
576/**
577 * nlmsg_multicast - multicast a netlink message
578 * @sk: netlink socket to spread messages to
579 * @skb: netlink message as socket buffer
580 * @portid: own netlink portid to avoid sending to yourself
581 * @group: multicast group id
582 * @flags: allocation flags
583 */
584static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
585 u32 portid, unsigned int group, gfp_t flags)
586{
587 int err;
588
589 NETLINK_CB(skb).dst_group = group;
590
591 err = netlink_broadcast(sk, skb, portid, group, flags);
592 if (err > 0)
593 err = 0;
594
595 return err;
596}
597
598/**
599 * nlmsg_unicast - unicast a netlink message
600 * @sk: netlink socket to spread message to
601 * @skb: netlink message as socket buffer
602 * @portid: netlink portid of the destination socket
603 */
604static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
605{
606 int err;
607
608 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
609 if (err > 0)
610 err = 0;
611
612 return err;
613}
614
615/**
616 * nlmsg_for_each_msg - iterate over a stream of messages
617 * @pos: loop counter, set to current message
618 * @head: head of message stream
619 * @len: length of message stream
620 * @rem: initialized to len, holds bytes currently remaining in stream
621 */
622#define nlmsg_for_each_msg(pos, head, len, rem) \
623 for (pos = head, rem = len; \
624 nlmsg_ok(pos, rem); \
625 pos = nlmsg_next(pos, &(rem)))
626
627/**
628 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
629 * @cb: netlink callback structure that stores the sequence number
630 * @nlh: netlink message header to write the flag to
631 *
632 * This function checks if the sequence (generation) number changed during dump
633 * and if it did, advertises it in the netlink message header.
634 *
635 * The correct way to use it is to set cb->seq to the generation counter when
636 * all locks for dumping have been acquired, and then call this function for
637 * each message that is generated.
638 *
639 * Note that due to initialisation concerns, 0 is an invalid sequence number
640 * and must not be used by code that uses this functionality.
641 */
642static inline void
643nl_dump_check_consistent(struct netlink_callback *cb,
644 struct nlmsghdr *nlh)
645{
646 if (cb->prev_seq && cb->seq != cb->prev_seq)
647 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
648 cb->prev_seq = cb->seq;
649}
650
651/**************************************************************************
652 * Netlink Attributes
653 **************************************************************************/
654
655/**
656 * nla_attr_size - length of attribute not including padding
657 * @payload: length of payload
658 */
659static inline int nla_attr_size(int payload)
660{
661 return NLA_HDRLEN + payload;
662}
663
664/**
665 * nla_total_size - total length of attribute including padding
666 * @payload: length of payload
667 */
668static inline int nla_total_size(int payload)
669{
670 return NLA_ALIGN(nla_attr_size(payload));
671}
672
673/**
674 * nla_padlen - length of padding at the tail of attribute
675 * @payload: length of payload
676 */
677static inline int nla_padlen(int payload)
678{
679 return nla_total_size(payload) - nla_attr_size(payload);
680}
681
682/**
683 * nla_type - attribute type
684 * @nla: netlink attribute
685 */
686static inline int nla_type(const struct nlattr *nla)
687{
688 return nla->nla_type & NLA_TYPE_MASK;
689}
690
691/**
692 * nla_data - head of payload
693 * @nla: netlink attribute
694 */
695static inline void *nla_data(const struct nlattr *nla)
696{
697 return (char *) nla + NLA_HDRLEN;
698}
699
700/**
701 * nla_len - length of payload
702 * @nla: netlink attribute
703 */
704static inline int nla_len(const struct nlattr *nla)
705{
706 return nla->nla_len - NLA_HDRLEN;
707}
708
709/**
710 * nla_ok - check if the netlink attribute fits into the remaining bytes
711 * @nla: netlink attribute
712 * @remaining: number of bytes remaining in attribute stream
713 */
714static inline int nla_ok(const struct nlattr *nla, int remaining)
715{
716 return remaining >= (int) sizeof(*nla) &&
717 nla->nla_len >= sizeof(*nla) &&
718 nla->nla_len <= remaining;
719}
720
721/**
722 * nla_next - next netlink attribute in attribute stream
723 * @nla: netlink attribute
724 * @remaining: number of bytes remaining in attribute stream
725 *
726 * Returns the next netlink attribute in the attribute stream and
727 * decrements remaining by the size of the current attribute.
728 */
729static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
730{
731 unsigned int totlen = NLA_ALIGN(nla->nla_len);
732
733 *remaining -= totlen;
734 return (struct nlattr *) ((char *) nla + totlen);
735}
736
737/**
738 * nla_find_nested - find attribute in a set of nested attributes
739 * @nla: attribute containing the nested attributes
740 * @attrtype: type of attribute to look for
741 *
742 * Returns the first attribute which matches the specified type.
743 */
744static inline struct nlattr *
745nla_find_nested(const struct nlattr *nla, int attrtype)
746{
747 return nla_find(nla_data(nla), nla_len(nla), attrtype);
748}
749
750/**
751 * nla_parse_nested - parse nested attributes
752 * @tb: destination array with maxtype+1 elements
753 * @maxtype: maximum attribute type to be expected
754 * @nla: attribute containing the nested attributes
755 * @policy: validation policy
756 * @extack: extended ACK report struct
757 *
758 * See nla_parse()
759 */
760static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
761 const struct nlattr *nla,
762 const struct nla_policy *policy,
763 struct netlink_ext_ack *extack)
764{
765 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
766 extack);
767}
768
769/**
770 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
771 * @skb: socket buffer to add attribute to
772 * @attrtype: attribute type
773 * @value: numeric value
774 */
775static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
776{
777 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
778 u8 tmp = value;
779
780 return nla_put(skb, attrtype, sizeof(u8), &tmp);
781}
782
783/**
784 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
785 * @skb: socket buffer to add attribute to
786 * @attrtype: attribute type
787 * @value: numeric value
788 */
789static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
790{
791 u16 tmp = value;
792
793 return nla_put(skb, attrtype, sizeof(u16), &tmp);
794}
795
796/**
797 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
798 * @skb: socket buffer to add attribute to
799 * @attrtype: attribute type
800 * @value: numeric value
801 */
802static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
803{
804 __be16 tmp = value;
805
806 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
807}
808
809/**
810 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
811 * @skb: socket buffer to add attribute to
812 * @attrtype: attribute type
813 * @value: numeric value
814 */
815static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
816{
817 __be16 tmp = value;
818
819 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
820}
821
822/**
823 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
824 * @skb: socket buffer to add attribute to
825 * @attrtype: attribute type
826 * @value: numeric value
827 */
828static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
829{
830 __le16 tmp = value;
831
832 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
833}
834
835/**
836 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
837 * @skb: socket buffer to add attribute to
838 * @attrtype: attribute type
839 * @value: numeric value
840 */
841static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
842{
843 u32 tmp = value;
844
845 return nla_put(skb, attrtype, sizeof(u32), &tmp);
846}
847
848/**
849 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
850 * @skb: socket buffer to add attribute to
851 * @attrtype: attribute type
852 * @value: numeric value
853 */
854static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
855{
856 __be32 tmp = value;
857
858 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
859}
860
861/**
862 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
863 * @skb: socket buffer to add attribute to
864 * @attrtype: attribute type
865 * @value: numeric value
866 */
867static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
868{
869 __be32 tmp = value;
870
871 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
872}
873
874/**
875 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
876 * @skb: socket buffer to add attribute to
877 * @attrtype: attribute type
878 * @value: numeric value
879 */
880static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
881{
882 __le32 tmp = value;
883
884 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
885}
886
887/**
888 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
889 * @skb: socket buffer to add attribute to
890 * @attrtype: attribute type
891 * @value: numeric value
892 * @padattr: attribute type for the padding
893 */
894static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
895 u64 value, int padattr)
896{
897 u64 tmp = value;
898
899 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
900}
901
902/**
903 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
904 * @skb: socket buffer to add attribute to
905 * @attrtype: attribute type
906 * @value: numeric value
907 * @padattr: attribute type for the padding
908 */
909static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
910 int padattr)
911{
912 __be64 tmp = value;
913
914 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
915}
916
917/**
918 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
919 * @skb: socket buffer to add attribute to
920 * @attrtype: attribute type
921 * @value: numeric value
922 * @padattr: attribute type for the padding
923 */
924static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
925 int padattr)
926{
927 __be64 tmp = value;
928
929 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
930 padattr);
931}
932
933/**
934 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
935 * @skb: socket buffer to add attribute to
936 * @attrtype: attribute type
937 * @value: numeric value
938 * @padattr: attribute type for the padding
939 */
940static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
941 int padattr)
942{
943 __le64 tmp = value;
944
945 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
946}
947
948/**
949 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
950 * @skb: socket buffer to add attribute to
951 * @attrtype: attribute type
952 * @value: numeric value
953 */
954static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
955{
956 s8 tmp = value;
957
958 return nla_put(skb, attrtype, sizeof(s8), &tmp);
959}
960
961/**
962 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
963 * @skb: socket buffer to add attribute to
964 * @attrtype: attribute type
965 * @value: numeric value
966 */
967static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
968{
969 s16 tmp = value;
970
971 return nla_put(skb, attrtype, sizeof(s16), &tmp);
972}
973
974/**
975 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
976 * @skb: socket buffer to add attribute to
977 * @attrtype: attribute type
978 * @value: numeric value
979 */
980static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
981{
982 s32 tmp = value;
983
984 return nla_put(skb, attrtype, sizeof(s32), &tmp);
985}
986
987/**
988 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
989 * @skb: socket buffer to add attribute to
990 * @attrtype: attribute type
991 * @value: numeric value
992 * @padattr: attribute type for the padding
993 */
994static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
995 int padattr)
996{
997 s64 tmp = value;
998
999 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1000}
1001
1002/**
1003 * nla_put_string - Add a string netlink attribute to a socket buffer
1004 * @skb: socket buffer to add attribute to
1005 * @attrtype: attribute type
1006 * @str: NUL terminated string
1007 */
1008static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1009 const char *str)
1010{
1011 return nla_put(skb, attrtype, strlen(str) + 1, str);
1012}
1013
1014/**
1015 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1016 * @skb: socket buffer to add attribute to
1017 * @attrtype: attribute type
1018 */
1019static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1020{
1021 return nla_put(skb, attrtype, 0, NULL);
1022}
1023
1024/**
1025 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1026 * @skb: socket buffer to add attribute to
1027 * @attrtype: attribute type
1028 * @njiffies: number of jiffies to convert to msecs
1029 * @padattr: attribute type for the padding
1030 */
1031static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1032 unsigned long njiffies, int padattr)
1033{
1034 u64 tmp = jiffies_to_msecs(njiffies);
1035
1036 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1037}
1038
1039/**
1040 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1041 * buffer
1042 * @skb: socket buffer to add attribute to
1043 * @attrtype: attribute type
1044 * @addr: IPv4 address
1045 */
1046static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1047 __be32 addr)
1048{
1049 __be32 tmp = addr;
1050
1051 return nla_put_be32(skb, attrtype, tmp);
1052}
1053
1054/**
1055 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1056 * buffer
1057 * @skb: socket buffer to add attribute to
1058 * @attrtype: attribute type
1059 * @addr: IPv6 address
1060 */
1061static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1062 const struct in6_addr *addr)
1063{
1064 return nla_put(skb, attrtype, sizeof(*addr), addr);
1065}
1066
1067/**
1068 * nla_get_u32 - return payload of u32 attribute
1069 * @nla: u32 netlink attribute
1070 */
1071static inline u32 nla_get_u32(const struct nlattr *nla)
1072{
1073 return *(u32 *) nla_data(nla);
1074}
1075
1076/**
1077 * nla_get_be32 - return payload of __be32 attribute
1078 * @nla: __be32 netlink attribute
1079 */
1080static inline __be32 nla_get_be32(const struct nlattr *nla)
1081{
1082 return *(__be32 *) nla_data(nla);
1083}
1084
1085/**
1086 * nla_get_le32 - return payload of __le32 attribute
1087 * @nla: __le32 netlink attribute
1088 */
1089static inline __le32 nla_get_le32(const struct nlattr *nla)
1090{
1091 return *(__le32 *) nla_data(nla);
1092}
1093
1094/**
1095 * nla_get_u16 - return payload of u16 attribute
1096 * @nla: u16 netlink attribute
1097 */
1098static inline u16 nla_get_u16(const struct nlattr *nla)
1099{
1100 return *(u16 *) nla_data(nla);
1101}
1102
1103/**
1104 * nla_get_be16 - return payload of __be16 attribute
1105 * @nla: __be16 netlink attribute
1106 */
1107static inline __be16 nla_get_be16(const struct nlattr *nla)
1108{
1109 return *(__be16 *) nla_data(nla);
1110}
1111
1112/**
1113 * nla_get_le16 - return payload of __le16 attribute
1114 * @nla: __le16 netlink attribute
1115 */
1116static inline __le16 nla_get_le16(const struct nlattr *nla)
1117{
1118 return *(__le16 *) nla_data(nla);
1119}
1120
1121/**
1122 * nla_get_u8 - return payload of u8 attribute
1123 * @nla: u8 netlink attribute
1124 */
1125static inline u8 nla_get_u8(const struct nlattr *nla)
1126{
1127 return *(u8 *) nla_data(nla);
1128}
1129
1130/**
1131 * nla_get_u64 - return payload of u64 attribute
1132 * @nla: u64 netlink attribute
1133 */
1134static inline u64 nla_get_u64(const struct nlattr *nla)
1135{
1136 u64 tmp;
1137
1138 nla_memcpy(&tmp, nla, sizeof(tmp));
1139
1140 return tmp;
1141}
1142
1143/**
1144 * nla_get_be64 - return payload of __be64 attribute
1145 * @nla: __be64 netlink attribute
1146 */
1147static inline __be64 nla_get_be64(const struct nlattr *nla)
1148{
1149 __be64 tmp;
1150
1151 nla_memcpy(&tmp, nla, sizeof(tmp));
1152
1153 return tmp;
1154}
1155
1156/**
1157 * nla_get_le64 - return payload of __le64 attribute
1158 * @nla: __le64 netlink attribute
1159 */
1160static inline __le64 nla_get_le64(const struct nlattr *nla)
1161{
1162 return *(__le64 *) nla_data(nla);
1163}
1164
1165/**
1166 * nla_get_s32 - return payload of s32 attribute
1167 * @nla: s32 netlink attribute
1168 */
1169static inline s32 nla_get_s32(const struct nlattr *nla)
1170{
1171 return *(s32 *) nla_data(nla);
1172}
1173
1174/**
1175 * nla_get_s16 - return payload of s16 attribute
1176 * @nla: s16 netlink attribute
1177 */
1178static inline s16 nla_get_s16(const struct nlattr *nla)
1179{
1180 return *(s16 *) nla_data(nla);
1181}
1182
1183/**
1184 * nla_get_s8 - return payload of s8 attribute
1185 * @nla: s8 netlink attribute
1186 */
1187static inline s8 nla_get_s8(const struct nlattr *nla)
1188{
1189 return *(s8 *) nla_data(nla);
1190}
1191
1192/**
1193 * nla_get_s64 - return payload of s64 attribute
1194 * @nla: s64 netlink attribute
1195 */
1196static inline s64 nla_get_s64(const struct nlattr *nla)
1197{
1198 s64 tmp;
1199
1200 nla_memcpy(&tmp, nla, sizeof(tmp));
1201
1202 return tmp;
1203}
1204
1205/**
1206 * nla_get_flag - return payload of flag attribute
1207 * @nla: flag netlink attribute
1208 */
1209static inline int nla_get_flag(const struct nlattr *nla)
1210{
1211 return !!nla;
1212}
1213
1214/**
1215 * nla_get_msecs - return payload of msecs attribute
1216 * @nla: msecs netlink attribute
1217 *
1218 * Returns the number of milliseconds in jiffies.
1219 */
1220static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1221{
1222 u64 msecs = nla_get_u64(nla);
1223
1224 return msecs_to_jiffies((unsigned long) msecs);
1225}
1226
1227/**
1228 * nla_get_in_addr - return payload of IPv4 address attribute
1229 * @nla: IPv4 address netlink attribute
1230 */
1231static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1232{
1233 return *(__be32 *) nla_data(nla);
1234}
1235
1236/**
1237 * nla_get_in6_addr - return payload of IPv6 address attribute
1238 * @nla: IPv6 address netlink attribute
1239 */
1240static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1241{
1242 struct in6_addr tmp;
1243
1244 nla_memcpy(&tmp, nla, sizeof(tmp));
1245 return tmp;
1246}
1247
1248/**
1249 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1250 * @nla: nla_bitfield32 attribute
1251 */
1252static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1253{
1254 struct nla_bitfield32 tmp;
1255
1256 nla_memcpy(&tmp, nla, sizeof(tmp));
1257 return tmp;
1258}
1259
1260/**
1261 * nla_memdup - duplicate attribute memory (kmemdup)
1262 * @src: netlink attribute to duplicate from
1263 * @gfp: GFP mask
1264 */
1265static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1266{
1267 return kmemdup(nla_data(src), nla_len(src), gfp);
1268}
1269
1270/**
1271 * nla_nest_start - Start a new level of nested attributes
1272 * @skb: socket buffer to add attributes to
1273 * @attrtype: attribute type of container
1274 *
1275 * Returns the container attribute
1276 */
1277static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1278{
1279 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1280
1281 if (nla_put(skb, attrtype, 0, NULL) < 0)
1282 return NULL;
1283
1284 return start;
1285}
1286
1287/**
1288 * nla_nest_end - Finalize nesting of attributes
1289 * @skb: socket buffer the attributes are stored in
1290 * @start: container attribute
1291 *
1292 * Corrects the container attribute header to include the all
1293 * appeneded attributes.
1294 *
1295 * Returns the total data length of the skb.
1296 */
1297static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1298{
1299 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1300 return skb->len;
1301}
1302
1303/**
1304 * nla_nest_cancel - Cancel nesting of attributes
1305 * @skb: socket buffer the message is stored in
1306 * @start: container attribute
1307 *
1308 * Removes the container attribute and including all nested
1309 * attributes. Returns -EMSGSIZE
1310 */
1311static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1312{
1313 nlmsg_trim(skb, start);
1314}
1315
1316/**
1317 * nla_validate_nested - Validate a stream of nested attributes
1318 * @start: container attribute
1319 * @maxtype: maximum attribute type to be expected
1320 * @policy: validation policy
1321 * @extack: extended ACK report struct
1322 *
1323 * Validates all attributes in the nested attribute stream against the
1324 * specified policy. Attributes with a type exceeding maxtype will be
1325 * ignored. See documenation of struct nla_policy for more details.
1326 *
1327 * Returns 0 on success or a negative error code.
1328 */
1329static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
1330 const struct nla_policy *policy,
1331 struct netlink_ext_ack *extack)
1332{
1333 return nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1334 extack);
1335}
1336
1337/**
1338 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1339 * @skb: socket buffer the message is stored in
1340 *
1341 * Return true if padding is needed to align the next attribute (nla_data()) to
1342 * a 64-bit aligned area.
1343 */
1344static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1345{
1346#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1347 /* The nlattr header is 4 bytes in size, that's why we test
1348 * if the skb->data _is_ aligned. A NOP attribute, plus
1349 * nlattr header for next attribute, will make nla_data()
1350 * 8-byte aligned.
1351 */
1352 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1353 return true;
1354#endif
1355 return false;
1356}
1357
1358/**
1359 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1360 * @skb: socket buffer the message is stored in
1361 * @padattr: attribute type for the padding
1362 *
1363 * Conditionally emit a padding netlink attribute in order to make
1364 * the next attribute we emit have a 64-bit aligned nla_data() area.
1365 * This will only be done in architectures which do not have
1366 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1367 *
1368 * Returns zero on success or a negative error code.
1369 */
1370static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1371{
1372 if (nla_need_padding_for_64bit(skb) &&
1373 !nla_reserve(skb, padattr, 0))
1374 return -EMSGSIZE;
1375
1376 return 0;
1377}
1378
1379/**
1380 * nla_total_size_64bit - total length of attribute including padding
1381 * @payload: length of payload
1382 */
1383static inline int nla_total_size_64bit(int payload)
1384{
1385 return NLA_ALIGN(nla_attr_size(payload))
1386#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1387 + NLA_ALIGN(nla_attr_size(0))
1388#endif
1389 ;
1390}
1391
1392/**
1393 * nla_for_each_attr - iterate over a stream of attributes
1394 * @pos: loop counter, set to current attribute
1395 * @head: head of attribute stream
1396 * @len: length of attribute stream
1397 * @rem: initialized to len, holds bytes currently remaining in stream
1398 */
1399#define nla_for_each_attr(pos, head, len, rem) \
1400 for (pos = head, rem = len; \
1401 nla_ok(pos, rem); \
1402 pos = nla_next(pos, &(rem)))
1403
1404/**
1405 * nla_for_each_nested - iterate over nested attributes
1406 * @pos: loop counter, set to current attribute
1407 * @nla: attribute containing the nested attributes
1408 * @rem: initialized to len, holds bytes currently remaining in stream
1409 */
1410#define nla_for_each_nested(pos, nla, rem) \
1411 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1412
1413/**
1414 * nla_is_last - Test if attribute is last in stream
1415 * @nla: attribute to test
1416 * @rem: bytes remaining in stream
1417 */
1418static inline bool nla_is_last(const struct nlattr *nla, int rem)
1419{
1420 return nla->nla_len == rem;
1421}
1422
1423#endif