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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#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_64bits(skb, type,
102 * value, padattr) add u64 attribute to skb
103 * nla_put_s8(skb, type, value) add s8 attribute to skb
104 * nla_put_s16(skb, type, value) add s16 attribute to skb
105 * nla_put_s32(skb, type, value) add s32 attribute to skb
106 * nla_put_s64(skb, type, value,
107 * padattr) add s64 attribute to skb
108 * nla_put_string(skb, type, str) add string attribute to skb
109 * nla_put_flag(skb, type) add flag attribute to skb
110 * nla_put_msecs(skb, type, jiffies,
111 * padattr) add msecs attribute to skb
112 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb
113 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb
114 *
115 * Nested Attributes Construction:
116 * nla_nest_start(skb, type) start a nested attribute
117 * nla_nest_end(skb, nla) finalize a nested attribute
118 * nla_nest_cancel(skb, nla) cancel nested attribute construction
119 *
120 * Attribute Length Calculations:
121 * nla_attr_size(payload) length of attribute w/o padding
122 * nla_total_size(payload) length of attribute w/ padding
123 * nla_padlen(payload) length of padding
124 *
125 * Attribute Payload Access:
126 * nla_data(nla) head of attribute payload
127 * nla_len(nla) length of attribute payload
128 *
129 * Attribute Payload Access for Basic Types:
130 * nla_get_u8(nla) get payload for a u8 attribute
131 * nla_get_u16(nla) get payload for a u16 attribute
132 * nla_get_u32(nla) get payload for a u32 attribute
133 * nla_get_u64(nla) get payload for a u64 attribute
134 * nla_get_s8(nla) get payload for a s8 attribute
135 * nla_get_s16(nla) get payload for a s16 attribute
136 * nla_get_s32(nla) get payload for a s32 attribute
137 * nla_get_s64(nla) get payload for a s64 attribute
138 * nla_get_flag(nla) return 1 if flag is true
139 * nla_get_msecs(nla) get payload for a msecs attribute
140 *
141 * Attribute Misc:
142 * nla_memcpy(dest, nla, count) copy attribute into memory
143 * nla_memcmp(nla, data, size) compare attribute with memory area
144 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
145 * nla_strcmp(nla, str) compare attribute with string
146 *
147 * Attribute Parsing:
148 * nla_ok(nla, remaining) does nla fit into remaining bytes?
149 * nla_next(nla, remaining) get next netlink attribute
150 * nla_validate() validate a stream of attributes
151 * nla_validate_nested() validate a stream of nested attributes
152 * nla_find() find attribute in stream of attributes
153 * nla_find_nested() find attribute in nested attributes
154 * nla_parse() parse and validate stream of attrs
155 * nla_parse_nested() parse nested attribuets
156 * nla_for_each_attr() loop over all attributes
157 * nla_for_each_nested() loop over the nested attributes
158 *=========================================================================
159 */
160
161 /**
162 * Standard attribute types to specify validation policy
163 */
164enum {
165 NLA_UNSPEC,
166 NLA_U8,
167 NLA_U16,
168 NLA_U32,
169 NLA_U64,
170 NLA_STRING,
171 NLA_FLAG,
172 NLA_MSECS,
173 NLA_NESTED,
174 NLA_NESTED_COMPAT,
175 NLA_NUL_STRING,
176 NLA_BINARY,
177 NLA_S8,
178 NLA_S16,
179 NLA_S32,
180 NLA_S64,
181 __NLA_TYPE_MAX,
182};
183
184#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
185
186/**
187 * struct nla_policy - attribute validation policy
188 * @type: Type of attribute or NLA_UNSPEC
189 * @len: Type specific length of payload
190 *
191 * Policies are defined as arrays of this struct, the array must be
192 * accessible by attribute type up to the highest identifier to be expected.
193 *
194 * Meaning of `len' field:
195 * NLA_STRING Maximum length of string
196 * NLA_NUL_STRING Maximum length of string (excluding NUL)
197 * NLA_FLAG Unused
198 * NLA_BINARY Maximum length of attribute payload
199 * NLA_NESTED Don't use `len' field -- length verification is
200 * done by checking len of nested header (or empty)
201 * NLA_NESTED_COMPAT Minimum length of structure payload
202 * NLA_U8, NLA_U16,
203 * NLA_U32, NLA_U64,
204 * NLA_S8, NLA_S16,
205 * NLA_S32, NLA_S64,
206 * NLA_MSECS Leaving the length field zero will verify the
207 * given type fits, using it verifies minimum length
208 * just like "All other"
209 * All other Minimum length of attribute payload
210 *
211 * Example:
212 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
213 * [ATTR_FOO] = { .type = NLA_U16 },
214 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
215 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
216 * };
217 */
218struct nla_policy {
219 u16 type;
220 u16 len;
221};
222
223/**
224 * struct nl_info - netlink source information
225 * @nlh: Netlink message header of original request
226 * @portid: Netlink PORTID of requesting application
227 */
228struct nl_info {
229 struct nlmsghdr *nlh;
230 struct net *nl_net;
231 u32 portid;
232};
233
234int netlink_rcv_skb(struct sk_buff *skb,
235 int (*cb)(struct sk_buff *, struct nlmsghdr *));
236int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
237 unsigned int group, int report, gfp_t flags);
238
239int nla_validate(const struct nlattr *head, int len, int maxtype,
240 const struct nla_policy *policy);
241int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
242 int len, const struct nla_policy *policy);
243int nla_policy_len(const struct nla_policy *, int);
244struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
245size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
246int nla_memcpy(void *dest, const struct nlattr *src, int count);
247int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
248int nla_strcmp(const struct nlattr *nla, const char *str);
249struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
250struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
251 int attrlen, int padattr);
252void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
253struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
254struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
255 int attrlen, int padattr);
256void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
257void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
258 const void *data);
259void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
260 const void *data, int padattr);
261void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
262int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
263int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
264 const void *data, int padattr);
265int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
266int nla_append(struct sk_buff *skb, int attrlen, const void *data);
267
268/**************************************************************************
269 * Netlink Messages
270 **************************************************************************/
271
272/**
273 * nlmsg_msg_size - length of netlink message not including padding
274 * @payload: length of message payload
275 */
276static inline int nlmsg_msg_size(int payload)
277{
278 return NLMSG_HDRLEN + payload;
279}
280
281/**
282 * nlmsg_total_size - length of netlink message including padding
283 * @payload: length of message payload
284 */
285static inline int nlmsg_total_size(int payload)
286{
287 return NLMSG_ALIGN(nlmsg_msg_size(payload));
288}
289
290/**
291 * nlmsg_padlen - length of padding at the message's tail
292 * @payload: length of message payload
293 */
294static inline int nlmsg_padlen(int payload)
295{
296 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
297}
298
299/**
300 * nlmsg_data - head of message payload
301 * @nlh: netlink message header
302 */
303static inline void *nlmsg_data(const struct nlmsghdr *nlh)
304{
305 return (unsigned char *) nlh + NLMSG_HDRLEN;
306}
307
308/**
309 * nlmsg_len - length of message payload
310 * @nlh: netlink message header
311 */
312static inline int nlmsg_len(const struct nlmsghdr *nlh)
313{
314 return nlh->nlmsg_len - NLMSG_HDRLEN;
315}
316
317/**
318 * nlmsg_attrdata - head of attributes data
319 * @nlh: netlink message header
320 * @hdrlen: length of family specific header
321 */
322static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
323 int hdrlen)
324{
325 unsigned char *data = nlmsg_data(nlh);
326 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
327}
328
329/**
330 * nlmsg_attrlen - length of attributes data
331 * @nlh: netlink message header
332 * @hdrlen: length of family specific header
333 */
334static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
335{
336 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
337}
338
339/**
340 * nlmsg_ok - check if the netlink message fits into the remaining bytes
341 * @nlh: netlink message header
342 * @remaining: number of bytes remaining in message stream
343 */
344static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
345{
346 return (remaining >= (int) sizeof(struct nlmsghdr) &&
347 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
348 nlh->nlmsg_len <= remaining);
349}
350
351/**
352 * nlmsg_next - next netlink message in message stream
353 * @nlh: netlink message header
354 * @remaining: number of bytes remaining in message stream
355 *
356 * Returns the next netlink message in the message stream and
357 * decrements remaining by the size of the current message.
358 */
359static inline struct nlmsghdr *
360nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
361{
362 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
363
364 *remaining -= totlen;
365
366 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
367}
368
369/**
370 * nlmsg_parse - parse attributes of a netlink message
371 * @nlh: netlink message header
372 * @hdrlen: length of family specific header
373 * @tb: destination array with maxtype+1 elements
374 * @maxtype: maximum attribute type to be expected
375 * @policy: validation policy
376 *
377 * See nla_parse()
378 */
379static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
380 struct nlattr *tb[], int maxtype,
381 const struct nla_policy *policy)
382{
383 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
384 return -EINVAL;
385
386 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
387 nlmsg_attrlen(nlh, hdrlen), policy);
388}
389
390/**
391 * nlmsg_find_attr - find a specific attribute in a netlink message
392 * @nlh: netlink message header
393 * @hdrlen: length of familiy specific header
394 * @attrtype: type of attribute to look for
395 *
396 * Returns the first attribute which matches the specified type.
397 */
398static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
399 int hdrlen, int attrtype)
400{
401 return nla_find(nlmsg_attrdata(nlh, hdrlen),
402 nlmsg_attrlen(nlh, hdrlen), attrtype);
403}
404
405/**
406 * nlmsg_validate - validate a netlink message including attributes
407 * @nlh: netlinket message header
408 * @hdrlen: length of familiy specific header
409 * @maxtype: maximum attribute type to be expected
410 * @policy: validation policy
411 */
412static inline int nlmsg_validate(const struct nlmsghdr *nlh,
413 int hdrlen, int maxtype,
414 const struct nla_policy *policy)
415{
416 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
417 return -EINVAL;
418
419 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
420 nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
421}
422
423/**
424 * nlmsg_report - need to report back to application?
425 * @nlh: netlink message header
426 *
427 * Returns 1 if a report back to the application is requested.
428 */
429static inline int nlmsg_report(const struct nlmsghdr *nlh)
430{
431 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
432}
433
434/**
435 * nlmsg_for_each_attr - iterate over a stream of attributes
436 * @pos: loop counter, set to current attribute
437 * @nlh: netlink message header
438 * @hdrlen: length of familiy specific header
439 * @rem: initialized to len, holds bytes currently remaining in stream
440 */
441#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
442 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
443 nlmsg_attrlen(nlh, hdrlen), rem)
444
445/**
446 * nlmsg_put - Add a new netlink message to an skb
447 * @skb: socket buffer to store message in
448 * @portid: netlink PORTID of requesting application
449 * @seq: sequence number of message
450 * @type: message type
451 * @payload: length of message payload
452 * @flags: message flags
453 *
454 * Returns NULL if the tailroom of the skb is insufficient to store
455 * the message header and payload.
456 */
457static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
458 int type, int payload, int flags)
459{
460 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
461 return NULL;
462
463 return __nlmsg_put(skb, portid, seq, type, payload, flags);
464}
465
466/**
467 * nlmsg_put_answer - Add a new callback based netlink message to an skb
468 * @skb: socket buffer to store message in
469 * @cb: netlink callback
470 * @type: message type
471 * @payload: length of message payload
472 * @flags: message flags
473 *
474 * Returns NULL if the tailroom of the skb is insufficient to store
475 * the message header and payload.
476 */
477static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
478 struct netlink_callback *cb,
479 int type, int payload,
480 int flags)
481{
482 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
483 type, payload, flags);
484}
485
486/**
487 * nlmsg_new - Allocate a new netlink message
488 * @payload: size of the message payload
489 * @flags: the type of memory to allocate.
490 *
491 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
492 * and a good default is needed.
493 */
494static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
495{
496 return alloc_skb(nlmsg_total_size(payload), flags);
497}
498
499/**
500 * nlmsg_end - Finalize a netlink message
501 * @skb: socket buffer the message is stored in
502 * @nlh: netlink message header
503 *
504 * Corrects the netlink message header to include the appeneded
505 * attributes. Only necessary if attributes have been added to
506 * the message.
507 */
508static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
509{
510 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
511}
512
513/**
514 * nlmsg_get_pos - return current position in netlink message
515 * @skb: socket buffer the message is stored in
516 *
517 * Returns a pointer to the current tail of the message.
518 */
519static inline void *nlmsg_get_pos(struct sk_buff *skb)
520{
521 return skb_tail_pointer(skb);
522}
523
524/**
525 * nlmsg_trim - Trim message to a mark
526 * @skb: socket buffer the message is stored in
527 * @mark: mark to trim to
528 *
529 * Trims the message to the provided mark.
530 */
531static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
532{
533 if (mark) {
534 WARN_ON((unsigned char *) mark < skb->data);
535 skb_trim(skb, (unsigned char *) mark - skb->data);
536 }
537}
538
539/**
540 * nlmsg_cancel - Cancel construction of a netlink message
541 * @skb: socket buffer the message is stored in
542 * @nlh: netlink message header
543 *
544 * Removes the complete netlink message including all
545 * attributes from the socket buffer again.
546 */
547static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
548{
549 nlmsg_trim(skb, nlh);
550}
551
552/**
553 * nlmsg_free - free a netlink message
554 * @skb: socket buffer of netlink message
555 */
556static inline void nlmsg_free(struct sk_buff *skb)
557{
558 kfree_skb(skb);
559}
560
561/**
562 * nlmsg_multicast - multicast a netlink message
563 * @sk: netlink socket to spread messages to
564 * @skb: netlink message as socket buffer
565 * @portid: own netlink portid to avoid sending to yourself
566 * @group: multicast group id
567 * @flags: allocation flags
568 */
569static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
570 u32 portid, unsigned int group, gfp_t flags)
571{
572 int err;
573
574 NETLINK_CB(skb).dst_group = group;
575
576 err = netlink_broadcast(sk, skb, portid, group, flags);
577 if (err > 0)
578 err = 0;
579
580 return err;
581}
582
583/**
584 * nlmsg_unicast - unicast a netlink message
585 * @sk: netlink socket to spread message to
586 * @skb: netlink message as socket buffer
587 * @portid: netlink portid of the destination socket
588 */
589static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
590{
591 int err;
592
593 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
594 if (err > 0)
595 err = 0;
596
597 return err;
598}
599
600/**
601 * nlmsg_for_each_msg - iterate over a stream of messages
602 * @pos: loop counter, set to current message
603 * @head: head of message stream
604 * @len: length of message stream
605 * @rem: initialized to len, holds bytes currently remaining in stream
606 */
607#define nlmsg_for_each_msg(pos, head, len, rem) \
608 for (pos = head, rem = len; \
609 nlmsg_ok(pos, rem); \
610 pos = nlmsg_next(pos, &(rem)))
611
612/**
613 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
614 * @cb: netlink callback structure that stores the sequence number
615 * @nlh: netlink message header to write the flag to
616 *
617 * This function checks if the sequence (generation) number changed during dump
618 * and if it did, advertises it in the netlink message header.
619 *
620 * The correct way to use it is to set cb->seq to the generation counter when
621 * all locks for dumping have been acquired, and then call this function for
622 * each message that is generated.
623 *
624 * Note that due to initialisation concerns, 0 is an invalid sequence number
625 * and must not be used by code that uses this functionality.
626 */
627static inline void
628nl_dump_check_consistent(struct netlink_callback *cb,
629 struct nlmsghdr *nlh)
630{
631 if (cb->prev_seq && cb->seq != cb->prev_seq)
632 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
633 cb->prev_seq = cb->seq;
634}
635
636/**************************************************************************
637 * Netlink Attributes
638 **************************************************************************/
639
640/**
641 * nla_attr_size - length of attribute not including padding
642 * @payload: length of payload
643 */
644static inline int nla_attr_size(int payload)
645{
646 return NLA_HDRLEN + payload;
647}
648
649/**
650 * nla_total_size - total length of attribute including padding
651 * @payload: length of payload
652 */
653static inline int nla_total_size(int payload)
654{
655 return NLA_ALIGN(nla_attr_size(payload));
656}
657
658/**
659 * nla_padlen - length of padding at the tail of attribute
660 * @payload: length of payload
661 */
662static inline int nla_padlen(int payload)
663{
664 return nla_total_size(payload) - nla_attr_size(payload);
665}
666
667/**
668 * nla_type - attribute type
669 * @nla: netlink attribute
670 */
671static inline int nla_type(const struct nlattr *nla)
672{
673 return nla->nla_type & NLA_TYPE_MASK;
674}
675
676/**
677 * nla_data - head of payload
678 * @nla: netlink attribute
679 */
680static inline void *nla_data(const struct nlattr *nla)
681{
682 return (char *) nla + NLA_HDRLEN;
683}
684
685/**
686 * nla_len - length of payload
687 * @nla: netlink attribute
688 */
689static inline int nla_len(const struct nlattr *nla)
690{
691 return nla->nla_len - NLA_HDRLEN;
692}
693
694/**
695 * nla_ok - check if the netlink attribute fits into the remaining bytes
696 * @nla: netlink attribute
697 * @remaining: number of bytes remaining in attribute stream
698 */
699static inline int nla_ok(const struct nlattr *nla, int remaining)
700{
701 return remaining >= (int) sizeof(*nla) &&
702 nla->nla_len >= sizeof(*nla) &&
703 nla->nla_len <= remaining;
704}
705
706/**
707 * nla_next - next netlink attribute in attribute stream
708 * @nla: netlink attribute
709 * @remaining: number of bytes remaining in attribute stream
710 *
711 * Returns the next netlink attribute in the attribute stream and
712 * decrements remaining by the size of the current attribute.
713 */
714static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
715{
716 unsigned int totlen = NLA_ALIGN(nla->nla_len);
717
718 *remaining -= totlen;
719 return (struct nlattr *) ((char *) nla + totlen);
720}
721
722/**
723 * nla_find_nested - find attribute in a set of nested attributes
724 * @nla: attribute containing the nested attributes
725 * @attrtype: type of attribute to look for
726 *
727 * Returns the first attribute which matches the specified type.
728 */
729static inline struct nlattr *
730nla_find_nested(const struct nlattr *nla, int attrtype)
731{
732 return nla_find(nla_data(nla), nla_len(nla), attrtype);
733}
734
735/**
736 * nla_parse_nested - parse nested attributes
737 * @tb: destination array with maxtype+1 elements
738 * @maxtype: maximum attribute type to be expected
739 * @nla: attribute containing the nested attributes
740 * @policy: validation policy
741 *
742 * See nla_parse()
743 */
744static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
745 const struct nlattr *nla,
746 const struct nla_policy *policy)
747{
748 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
749}
750
751/**
752 * nla_put_u8 - Add a u8 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_u8(struct sk_buff *skb, int attrtype, u8 value)
758{
759 return nla_put(skb, attrtype, sizeof(u8), &value);
760}
761
762/**
763 * nla_put_u16 - Add a u16 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_u16(struct sk_buff *skb, int attrtype, u16 value)
769{
770 return nla_put(skb, attrtype, sizeof(u16), &value);
771}
772
773/**
774 * nla_put_be16 - Add a __be16 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_be16(struct sk_buff *skb, int attrtype, __be16 value)
780{
781 return nla_put(skb, attrtype, sizeof(__be16), &value);
782}
783
784/**
785 * nla_put_net16 - Add 16-bit network byte order 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_net16(struct sk_buff *skb, int attrtype, __be16 value)
791{
792 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, value);
793}
794
795/**
796 * nla_put_le16 - Add a __le16 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_le16(struct sk_buff *skb, int attrtype, __le16 value)
802{
803 return nla_put(skb, attrtype, sizeof(__le16), &value);
804}
805
806/**
807 * nla_put_u32 - Add a u32 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_u32(struct sk_buff *skb, int attrtype, u32 value)
813{
814 return nla_put(skb, attrtype, sizeof(u32), &value);
815}
816
817/**
818 * nla_put_be32 - Add a __be32 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_be32(struct sk_buff *skb, int attrtype, __be32 value)
824{
825 return nla_put(skb, attrtype, sizeof(__be32), &value);
826}
827
828/**
829 * nla_put_net32 - Add 32-bit network byte order 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_net32(struct sk_buff *skb, int attrtype, __be32 value)
835{
836 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, value);
837}
838
839/**
840 * nla_put_le32 - Add a __le32 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_le32(struct sk_buff *skb, int attrtype, __le32 value)
846{
847 return nla_put(skb, attrtype, sizeof(__le32), &value);
848}
849
850/**
851 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
852 * @skb: socket buffer to add attribute to
853 * @attrtype: attribute type
854 * @value: numeric value
855 * @padattr: attribute type for the padding
856 */
857static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
858 u64 value, int padattr)
859{
860 return nla_put_64bit(skb, attrtype, sizeof(u64), &value, padattr);
861}
862
863/**
864 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
865 * @skb: socket buffer to add attribute to
866 * @attrtype: attribute type
867 * @value: numeric value
868 * @padattr: attribute type for the padding
869 */
870static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
871 int padattr)
872{
873 return nla_put_64bit(skb, attrtype, sizeof(__be64), &value, padattr);
874}
875
876/**
877 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
878 * @skb: socket buffer to add attribute to
879 * @attrtype: attribute type
880 * @value: numeric value
881 * @padattr: attribute type for the padding
882 */
883static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
884 int padattr)
885{
886 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, value,
887 padattr);
888}
889
890/**
891 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
892 * @skb: socket buffer to add attribute to
893 * @attrtype: attribute type
894 * @value: numeric value
895 * @padattr: attribute type for the padding
896 */
897static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
898 int padattr)
899{
900 return nla_put_64bit(skb, attrtype, sizeof(__le64), &value, padattr);
901}
902
903/**
904 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
905 * @skb: socket buffer to add attribute to
906 * @attrtype: attribute type
907 * @value: numeric value
908 */
909static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
910{
911 return nla_put(skb, attrtype, sizeof(s8), &value);
912}
913
914/**
915 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
916 * @skb: socket buffer to add attribute to
917 * @attrtype: attribute type
918 * @value: numeric value
919 */
920static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
921{
922 return nla_put(skb, attrtype, sizeof(s16), &value);
923}
924
925/**
926 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
927 * @skb: socket buffer to add attribute to
928 * @attrtype: attribute type
929 * @value: numeric value
930 */
931static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
932{
933 return nla_put(skb, attrtype, sizeof(s32), &value);
934}
935
936/**
937 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
938 * @skb: socket buffer to add attribute to
939 * @attrtype: attribute type
940 * @value: numeric value
941 * @padattr: attribute type for the padding
942 */
943static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
944 int padattr)
945{
946 return nla_put_64bit(skb, attrtype, sizeof(s64), &value, padattr);
947}
948
949/**
950 * nla_put_string - Add a string netlink attribute to a socket buffer
951 * @skb: socket buffer to add attribute to
952 * @attrtype: attribute type
953 * @str: NUL terminated string
954 */
955static inline int nla_put_string(struct sk_buff *skb, int attrtype,
956 const char *str)
957{
958 return nla_put(skb, attrtype, strlen(str) + 1, str);
959}
960
961/**
962 * nla_put_flag - Add a flag netlink attribute to a socket buffer
963 * @skb: socket buffer to add attribute to
964 * @attrtype: attribute type
965 */
966static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
967{
968 return nla_put(skb, attrtype, 0, NULL);
969}
970
971/**
972 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
973 * @skb: socket buffer to add attribute to
974 * @attrtype: attribute type
975 * @njiffies: number of jiffies to convert to msecs
976 * @padattr: attribute type for the padding
977 */
978static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
979 unsigned long njiffies, int padattr)
980{
981 u64 tmp = jiffies_to_msecs(njiffies);
982
983 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
984}
985
986/**
987 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
988 * buffer
989 * @skb: socket buffer to add attribute to
990 * @attrtype: attribute type
991 * @addr: IPv4 address
992 */
993static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
994 __be32 addr)
995{
996 return nla_put_be32(skb, attrtype, addr);
997}
998
999/**
1000 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1001 * buffer
1002 * @skb: socket buffer to add attribute to
1003 * @attrtype: attribute type
1004 * @addr: IPv6 address
1005 */
1006static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1007 const struct in6_addr *addr)
1008{
1009 return nla_put(skb, attrtype, sizeof(*addr), addr);
1010}
1011
1012/**
1013 * nla_get_u32 - return payload of u32 attribute
1014 * @nla: u32 netlink attribute
1015 */
1016static inline u32 nla_get_u32(const struct nlattr *nla)
1017{
1018 return *(u32 *) nla_data(nla);
1019}
1020
1021/**
1022 * nla_get_be32 - return payload of __be32 attribute
1023 * @nla: __be32 netlink attribute
1024 */
1025static inline __be32 nla_get_be32(const struct nlattr *nla)
1026{
1027 return *(__be32 *) nla_data(nla);
1028}
1029
1030/**
1031 * nla_get_le32 - return payload of __le32 attribute
1032 * @nla: __le32 netlink attribute
1033 */
1034static inline __le32 nla_get_le32(const struct nlattr *nla)
1035{
1036 return *(__le32 *) nla_data(nla);
1037}
1038
1039/**
1040 * nla_get_u16 - return payload of u16 attribute
1041 * @nla: u16 netlink attribute
1042 */
1043static inline u16 nla_get_u16(const struct nlattr *nla)
1044{
1045 return *(u16 *) nla_data(nla);
1046}
1047
1048/**
1049 * nla_get_be16 - return payload of __be16 attribute
1050 * @nla: __be16 netlink attribute
1051 */
1052static inline __be16 nla_get_be16(const struct nlattr *nla)
1053{
1054 return *(__be16 *) nla_data(nla);
1055}
1056
1057/**
1058 * nla_get_le16 - return payload of __le16 attribute
1059 * @nla: __le16 netlink attribute
1060 */
1061static inline __le16 nla_get_le16(const struct nlattr *nla)
1062{
1063 return *(__le16 *) nla_data(nla);
1064}
1065
1066/**
1067 * nla_get_u8 - return payload of u8 attribute
1068 * @nla: u8 netlink attribute
1069 */
1070static inline u8 nla_get_u8(const struct nlattr *nla)
1071{
1072 return *(u8 *) nla_data(nla);
1073}
1074
1075/**
1076 * nla_get_u64 - return payload of u64 attribute
1077 * @nla: u64 netlink attribute
1078 */
1079static inline u64 nla_get_u64(const struct nlattr *nla)
1080{
1081 u64 tmp;
1082
1083 nla_memcpy(&tmp, nla, sizeof(tmp));
1084
1085 return tmp;
1086}
1087
1088/**
1089 * nla_get_be64 - return payload of __be64 attribute
1090 * @nla: __be64 netlink attribute
1091 */
1092static inline __be64 nla_get_be64(const struct nlattr *nla)
1093{
1094 __be64 tmp;
1095
1096 nla_memcpy(&tmp, nla, sizeof(tmp));
1097
1098 return tmp;
1099}
1100
1101/**
1102 * nla_get_le64 - return payload of __le64 attribute
1103 * @nla: __le64 netlink attribute
1104 */
1105static inline __le64 nla_get_le64(const struct nlattr *nla)
1106{
1107 return *(__le64 *) nla_data(nla);
1108}
1109
1110/**
1111 * nla_get_s32 - return payload of s32 attribute
1112 * @nla: s32 netlink attribute
1113 */
1114static inline s32 nla_get_s32(const struct nlattr *nla)
1115{
1116 return *(s32 *) nla_data(nla);
1117}
1118
1119/**
1120 * nla_get_s16 - return payload of s16 attribute
1121 * @nla: s16 netlink attribute
1122 */
1123static inline s16 nla_get_s16(const struct nlattr *nla)
1124{
1125 return *(s16 *) nla_data(nla);
1126}
1127
1128/**
1129 * nla_get_s8 - return payload of s8 attribute
1130 * @nla: s8 netlink attribute
1131 */
1132static inline s8 nla_get_s8(const struct nlattr *nla)
1133{
1134 return *(s8 *) nla_data(nla);
1135}
1136
1137/**
1138 * nla_get_s64 - return payload of s64 attribute
1139 * @nla: s64 netlink attribute
1140 */
1141static inline s64 nla_get_s64(const struct nlattr *nla)
1142{
1143 s64 tmp;
1144
1145 nla_memcpy(&tmp, nla, sizeof(tmp));
1146
1147 return tmp;
1148}
1149
1150/**
1151 * nla_get_flag - return payload of flag attribute
1152 * @nla: flag netlink attribute
1153 */
1154static inline int nla_get_flag(const struct nlattr *nla)
1155{
1156 return !!nla;
1157}
1158
1159/**
1160 * nla_get_msecs - return payload of msecs attribute
1161 * @nla: msecs netlink attribute
1162 *
1163 * Returns the number of milliseconds in jiffies.
1164 */
1165static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1166{
1167 u64 msecs = nla_get_u64(nla);
1168
1169 return msecs_to_jiffies((unsigned long) msecs);
1170}
1171
1172/**
1173 * nla_get_in_addr - return payload of IPv4 address attribute
1174 * @nla: IPv4 address netlink attribute
1175 */
1176static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1177{
1178 return *(__be32 *) nla_data(nla);
1179}
1180
1181/**
1182 * nla_get_in6_addr - return payload of IPv6 address attribute
1183 * @nla: IPv6 address netlink attribute
1184 */
1185static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1186{
1187 struct in6_addr tmp;
1188
1189 nla_memcpy(&tmp, nla, sizeof(tmp));
1190 return tmp;
1191}
1192
1193/**
1194 * nla_memdup - duplicate attribute memory (kmemdup)
1195 * @src: netlink attribute to duplicate from
1196 * @gfp: GFP mask
1197 */
1198static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1199{
1200 return kmemdup(nla_data(src), nla_len(src), gfp);
1201}
1202
1203/**
1204 * nla_nest_start - Start a new level of nested attributes
1205 * @skb: socket buffer to add attributes to
1206 * @attrtype: attribute type of container
1207 *
1208 * Returns the container attribute
1209 */
1210static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1211{
1212 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1213
1214 if (nla_put(skb, attrtype, 0, NULL) < 0)
1215 return NULL;
1216
1217 return start;
1218}
1219
1220/**
1221 * nla_nest_end - Finalize nesting of attributes
1222 * @skb: socket buffer the attributes are stored in
1223 * @start: container attribute
1224 *
1225 * Corrects the container attribute header to include the all
1226 * appeneded attributes.
1227 *
1228 * Returns the total data length of the skb.
1229 */
1230static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1231{
1232 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1233 return skb->len;
1234}
1235
1236/**
1237 * nla_nest_cancel - Cancel nesting of attributes
1238 * @skb: socket buffer the message is stored in
1239 * @start: container attribute
1240 *
1241 * Removes the container attribute and including all nested
1242 * attributes. Returns -EMSGSIZE
1243 */
1244static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1245{
1246 nlmsg_trim(skb, start);
1247}
1248
1249/**
1250 * nla_validate_nested - Validate a stream of nested attributes
1251 * @start: container attribute
1252 * @maxtype: maximum attribute type to be expected
1253 * @policy: validation policy
1254 *
1255 * Validates all attributes in the nested attribute stream against the
1256 * specified policy. Attributes with a type exceeding maxtype will be
1257 * ignored. See documenation of struct nla_policy for more details.
1258 *
1259 * Returns 0 on success or a negative error code.
1260 */
1261static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
1262 const struct nla_policy *policy)
1263{
1264 return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
1265}
1266
1267/**
1268 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1269 * @skb: socket buffer the message is stored in
1270 *
1271 * Return true if padding is needed to align the next attribute (nla_data()) to
1272 * a 64-bit aligned area.
1273 */
1274static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1275{
1276#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1277 /* The nlattr header is 4 bytes in size, that's why we test
1278 * if the skb->data _is_ aligned. A NOP attribute, plus
1279 * nlattr header for next attribute, will make nla_data()
1280 * 8-byte aligned.
1281 */
1282 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1283 return true;
1284#endif
1285 return false;
1286}
1287
1288/**
1289 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1290 * @skb: socket buffer the message is stored in
1291 * @padattr: attribute type for the padding
1292 *
1293 * Conditionally emit a padding netlink attribute in order to make
1294 * the next attribute we emit have a 64-bit aligned nla_data() area.
1295 * This will only be done in architectures which do not have
1296 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1297 *
1298 * Returns zero on success or a negative error code.
1299 */
1300static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1301{
1302 if (nla_need_padding_for_64bit(skb) &&
1303 !nla_reserve(skb, padattr, 0))
1304 return -EMSGSIZE;
1305
1306 return 0;
1307}
1308
1309/**
1310 * nla_total_size_64bit - total length of attribute including padding
1311 * @payload: length of payload
1312 */
1313static inline int nla_total_size_64bit(int payload)
1314{
1315 return NLA_ALIGN(nla_attr_size(payload))
1316#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1317 + NLA_ALIGN(nla_attr_size(0))
1318#endif
1319 ;
1320}
1321
1322/**
1323 * nla_for_each_attr - iterate over a stream of attributes
1324 * @pos: loop counter, set to current attribute
1325 * @head: head of attribute stream
1326 * @len: length of attribute stream
1327 * @rem: initialized to len, holds bytes currently remaining in stream
1328 */
1329#define nla_for_each_attr(pos, head, len, rem) \
1330 for (pos = head, rem = len; \
1331 nla_ok(pos, rem); \
1332 pos = nla_next(pos, &(rem)))
1333
1334/**
1335 * nla_for_each_nested - iterate over nested attributes
1336 * @pos: loop counter, set to current attribute
1337 * @nla: attribute containing the nested attributes
1338 * @rem: initialized to len, holds bytes currently remaining in stream
1339 */
1340#define nla_for_each_nested(pos, nla, rem) \
1341 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1342
1343/**
1344 * nla_is_last - Test if attribute is last in stream
1345 * @nla: attribute to test
1346 * @rem: bytes remaining in stream
1347 */
1348static inline bool nla_is_last(const struct nlattr *nla, int rem)
1349{
1350 return nla->nla_len == rem;
1351}
1352
1353#endif