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