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