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