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Thomas Grafbfa83a92005-11-10 02:25:51 +01001#ifndef __NET_NETLINK_H
2#define __NET_NETLINK_H
3
4#include <linux/types.h>
5#include <linux/netlink.h>
6
7/* ========================================================================
8 * Netlink Messages and Attributes Interface (As Seen On TV)
9 * ------------------------------------------------------------------------
10 * Messages Interface
11 * ------------------------------------------------------------------------
12 *
13 * Message Format:
14 * <--- nlmsg_total_size(payload) --->
15 * <-- nlmsg_msg_size(payload) ->
16 * +----------+- - -+-------------+- - -+-------- - -
17 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr
18 * +----------+- - -+-------------+- - -+-------- - -
19 * nlmsg_data(nlh)---^ ^
20 * nlmsg_next(nlh)-----------------------+
21 *
22 * Payload Format:
23 * <---------------------- nlmsg_len(nlh) --------------------->
24 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
25 * +----------------------+- - -+--------------------------------+
26 * | Family Header | Pad | Attributes |
27 * +----------------------+- - -+--------------------------------+
28 * nlmsg_attrdata(nlh, hdrlen)---^
29 *
30 * Data Structures:
31 * struct nlmsghdr netlink message header
32 *
33 * Message Construction:
34 * nlmsg_new() create a new netlink message
35 * nlmsg_put() add a netlink message to an skb
36 * nlmsg_put_answer() callback based nlmsg_put()
37 * nlmsg_end() finanlize netlink message
38 * nlmsg_cancel() cancel message construction
39 * nlmsg_free() free a netlink message
40 *
41 * Message Sending:
42 * nlmsg_multicast() multicast message to several groups
43 * nlmsg_unicast() unicast a message to a single socket
44 *
45 * Message Length Calculations:
46 * nlmsg_msg_size(payload) length of message w/o padding
47 * nlmsg_total_size(payload) length of message w/ padding
48 * nlmsg_padlen(payload) length of padding at tail
49 *
50 * Message Payload Access:
51 * nlmsg_data(nlh) head of message payload
52 * nlmsg_len(nlh) length of message payload
53 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
54 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
55 *
56 * Message Parsing:
57 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
58 * nlmsg_next(nlh, remaining) get next netlink message
59 * nlmsg_parse() parse attributes of a message
60 * nlmsg_find_attr() find an attribute in a message
61 * nlmsg_for_each_msg() loop over all messages
62 * nlmsg_validate() validate netlink message incl. attrs
63 * nlmsg_for_each_attr() loop over all attributes
64 *
65 * ------------------------------------------------------------------------
66 * Attributes Interface
67 * ------------------------------------------------------------------------
68 *
69 * Attribute Format:
70 * <------- nla_total_size(payload) ------->
71 * <---- nla_attr_size(payload) ----->
72 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
73 * | Header | Pad | Payload | Pad | Header
74 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
75 * <- nla_len(nla) -> ^
76 * nla_data(nla)----^ |
77 * nla_next(nla)-----------------------------'
78 *
79 * Data Structures:
80 * struct nlattr netlink attribtue header
81 *
82 * Attribute Construction:
83 * nla_reserve(skb, type, len) reserve skb tailroom for an attribute
84 * nla_put(skb, type, len, data) add attribute to skb
85 *
86 * Attribute Construction for Basic Types:
87 * nla_put_u8(skb, type, value) add u8 attribute to skb
88 * nla_put_u16(skb, type, value) add u16 attribute to skb
89 * nla_put_u32(skb, type, value) add u32 attribute to skb
90 * nla_put_u64(skb, type, value) add u64 attribute to skb
91 * nla_put_string(skb, type, str) add string attribute to skb
92 * nla_put_flag(skb, type) add flag attribute to skb
93 * nla_put_msecs(skb, type, jiffies) add msecs attribute to skb
94 *
95 * Exceptions Based Attribute Construction:
96 * NLA_PUT(skb, type, len, data) add attribute to skb
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 * The meaning of these functions is equal to their lower case
106 * variants but they jump to the label nla_put_failure in case
107 * of a failure.
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_flag(nla) return 1 if flag is true
129 * nla_get_msecs(nla) get payload for a msecs attribute
130 *
131 * Attribute Misc:
132 * nla_memcpy(dest, nla, count) copy attribute into memory
133 * nla_memcmp(nla, data, size) compare attribute with memory area
134 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
135 * nla_strcmp(nla, str) compare attribute with string
136 *
137 * Attribute Parsing:
138 * nla_ok(nla, remaining) does nla fit into remaining bytes?
139 * nla_next(nla, remaining) get next netlink attribute
140 * nla_validate() validate a stream of attributes
141 * nla_find() find attribute in stream of attributes
142 * nla_parse() parse and validate stream of attrs
143 * nla_parse_nested() parse nested attribuets
144 * nla_for_each_attr() loop over all attributes
145 *=========================================================================
146 */
147
148 /**
149 * Standard attribute types to specify validation policy
150 */
151enum {
152 NLA_UNSPEC,
153 NLA_U8,
154 NLA_U16,
155 NLA_U32,
156 NLA_U64,
157 NLA_STRING,
158 NLA_FLAG,
159 NLA_MSECS,
160 NLA_NESTED,
161 __NLA_TYPE_MAX,
162};
163
164#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
165
166/**
167 * struct nla_policy - attribute validation policy
168 * @type: Type of attribute or NLA_UNSPEC
169 * @minlen: Minimal length of payload required to be available
170 *
171 * Policies are defined as arrays of this struct, the array must be
172 * accessible by attribute type up to the highest identifier to be expected.
173 *
174 * Example:
175 * static struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = {
176 * [ATTR_FOO] = { .type = NLA_U16 },
177 * [ATTR_BAR] = { .type = NLA_STRING },
178 * [ATTR_BAZ] = { .minlen = sizeof(struct mystruct) },
179 * };
180 */
181struct nla_policy {
182 u16 type;
183 u16 minlen;
184};
185
Thomas Graf82ace472005-11-10 02:25:53 +0100186extern void netlink_run_queue(struct sock *sk, unsigned int *qlen,
187 int (*cb)(struct sk_buff *,
188 struct nlmsghdr *, int *));
189extern void netlink_queue_skip(struct nlmsghdr *nlh,
190 struct sk_buff *skb);
191
Thomas Grafbfa83a92005-11-10 02:25:51 +0100192extern int nla_validate(struct nlattr *head, int len, int maxtype,
193 struct nla_policy *policy);
194extern int nla_parse(struct nlattr *tb[], int maxtype,
195 struct nlattr *head, int len,
196 struct nla_policy *policy);
197extern struct nlattr * nla_find(struct nlattr *head, int len, int attrtype);
198extern size_t nla_strlcpy(char *dst, const struct nlattr *nla,
199 size_t dstsize);
200extern int nla_memcpy(void *dest, struct nlattr *src, int count);
201extern int nla_memcmp(const struct nlattr *nla, const void *data,
202 size_t size);
203extern int nla_strcmp(const struct nlattr *nla, const char *str);
204extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype,
205 int attrlen);
206extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype,
207 int attrlen);
208extern void __nla_put(struct sk_buff *skb, int attrtype,
209 int attrlen, const void *data);
210extern int nla_put(struct sk_buff *skb, int attrtype,
211 int attrlen, const void *data);
212
213/**************************************************************************
214 * Netlink Messages
215 **************************************************************************/
216
217/**
218 * nlmsg_msg_size - length of netlink message not including padding
219 * @payload: length of message payload
220 */
221static inline int nlmsg_msg_size(int payload)
222{
223 return NLMSG_HDRLEN + payload;
224}
225
226/**
227 * nlmsg_total_size - length of netlink message including padding
228 * @payload: length of message payload
229 */
230static inline int nlmsg_total_size(int payload)
231{
232 return NLMSG_ALIGN(nlmsg_msg_size(payload));
233}
234
235/**
236 * nlmsg_padlen - length of padding at the message's tail
237 * @payload: length of message payload
238 */
239static inline int nlmsg_padlen(int payload)
240{
241 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
242}
243
244/**
245 * nlmsg_data - head of message payload
246 * @nlh: netlink messsage header
247 */
248static inline void *nlmsg_data(const struct nlmsghdr *nlh)
249{
250 return (unsigned char *) nlh + NLMSG_HDRLEN;
251}
252
253/**
254 * nlmsg_len - length of message payload
255 * @nlh: netlink message header
256 */
257static inline int nlmsg_len(const struct nlmsghdr *nlh)
258{
259 return nlh->nlmsg_len - NLMSG_HDRLEN;
260}
261
262/**
263 * nlmsg_attrdata - head of attributes data
264 * @nlh: netlink message header
265 * @hdrlen: length of family specific header
266 */
267static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
268 int hdrlen)
269{
270 unsigned char *data = nlmsg_data(nlh);
271 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
272}
273
274/**
275 * nlmsg_attrlen - length of attributes data
276 * @nlh: netlink message header
277 * @hdrlen: length of family specific header
278 */
279static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
280{
281 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
282}
283
284/**
285 * nlmsg_ok - check if the netlink message fits into the remaining bytes
286 * @nlh: netlink message header
287 * @remaining: number of bytes remaining in message stream
288 */
289static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
290{
291 return (remaining >= sizeof(struct nlmsghdr) &&
292 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
293 nlh->nlmsg_len <= remaining);
294}
295
296/**
297 * nlmsg_next - next netlink message in message stream
298 * @nlh: netlink message header
299 * @remaining: number of bytes remaining in message stream
300 *
301 * Returns the next netlink message in the message stream and
302 * decrements remaining by the size of the current message.
303 */
304static inline struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining)
305{
306 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
307
308 *remaining -= totlen;
309
310 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
311}
312
313/**
314 * nlmsg_parse - parse attributes of a netlink message
315 * @nlh: netlink message header
316 * @hdrlen: length of family specific header
317 * @tb: destination array with maxtype+1 elements
318 * @maxtype: maximum attribute type to be expected
319 * @policy: validation policy
320 *
321 * See nla_parse()
322 */
323static inline int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen,
324 struct nlattr *tb[], int maxtype,
325 struct nla_policy *policy)
326{
327 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
328 return -EINVAL;
329
330 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
331 nlmsg_attrlen(nlh, hdrlen), policy);
332}
333
334/**
335 * nlmsg_find_attr - find a specific attribute in a netlink message
336 * @nlh: netlink message header
337 * @hdrlen: length of familiy specific header
338 * @attrtype: type of attribute to look for
339 *
340 * Returns the first attribute which matches the specified type.
341 */
342static inline struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh,
343 int hdrlen, int attrtype)
344{
345 return nla_find(nlmsg_attrdata(nlh, hdrlen),
346 nlmsg_attrlen(nlh, hdrlen), attrtype);
347}
348
349/**
350 * nlmsg_validate - validate a netlink message including attributes
351 * @nlh: netlinket message header
352 * @hdrlen: length of familiy specific header
353 * @maxtype: maximum attribute type to be expected
354 * @policy: validation policy
355 */
356static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype,
357 struct nla_policy *policy)
358{
359 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
360 return -EINVAL;
361
362 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
363 nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
364}
365
366/**
367 * nlmsg_for_each_attr - iterate over a stream of attributes
368 * @pos: loop counter, set to current attribute
369 * @nlh: netlink message header
370 * @hdrlen: length of familiy specific header
371 * @rem: initialized to len, holds bytes currently remaining in stream
372 */
373#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
374 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
375 nlmsg_attrlen(nlh, hdrlen), rem)
376
377#if 0
378/* FIXME: Enable once all users have been converted */
379
380/**
381 * __nlmsg_put - Add a new netlink message to an skb
382 * @skb: socket buffer to store message in
383 * @pid: netlink process id
384 * @seq: sequence number of message
385 * @type: message type
386 * @payload: length of message payload
387 * @flags: message flags
388 *
389 * The caller is responsible to ensure that the skb provides enough
390 * tailroom for both the netlink header and payload.
391 */
392static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid,
393 u32 seq, int type, int payload,
394 int flags)
395{
396 struct nlmsghdr *nlh;
397
398 nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload));
399 nlh->nlmsg_type = type;
400 nlh->nlmsg_len = nlmsg_msg_size(payload);
401 nlh->nlmsg_flags = flags;
402 nlh->nlmsg_pid = pid;
403 nlh->nlmsg_seq = seq;
404
405 memset((unsigned char *) nlmsg_data(nlh) + payload, 0,
406 nlmsg_padlen(payload));
407
408 return nlh;
409}
410#endif
411
412/**
413 * nlmsg_put - Add a new netlink message to an skb
414 * @skb: socket buffer to store message in
415 * @pid: netlink process id
416 * @seq: sequence number of message
417 * @type: message type
418 * @payload: length of message payload
419 * @flags: message flags
420 *
421 * Returns NULL if the tailroom of the skb is insufficient to store
422 * the message header and payload.
423 */
424static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
425 int type, int payload, int flags)
426{
427 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
428 return NULL;
429
430 return __nlmsg_put(skb, pid, seq, type, payload, flags);
431}
432
433/**
434 * nlmsg_put_answer - Add a new callback based netlink message to an skb
435 * @skb: socket buffer to store message in
436 * @cb: netlink callback
437 * @type: message type
438 * @payload: length of message payload
439 * @flags: message flags
440 *
441 * Returns NULL if the tailroom of the skb is insufficient to store
442 * the message header and payload.
443 */
444static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
445 struct netlink_callback *cb,
446 int type, int payload,
447 int flags)
448{
449 return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
450 type, payload, flags);
451}
452
453/**
454 * nlmsg_new - Allocate a new netlink message
455 * @size: maximum size of message
456 *
457 * Use NLMSG_GOODSIZE if size isn't know and you need a good default size.
458 */
459static inline struct sk_buff *nlmsg_new(int size)
460{
461 return alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
462}
463
464/**
465 * nlmsg_end - Finalize a netlink message
466 * @skb: socket buffer the message is stored in
467 * @nlh: netlink message header
468 *
469 * Corrects the netlink message header to include the appeneded
470 * attributes. Only necessary if attributes have been added to
471 * the message.
472 *
473 * Returns the total data length of the skb.
474 */
475static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
476{
477 nlh->nlmsg_len = skb->tail - (unsigned char *) nlh;
478
479 return skb->len;
480}
481
482/**
483 * nlmsg_cancel - Cancel construction of a netlink message
484 * @skb: socket buffer the message is stored in
485 * @nlh: netlink message header
486 *
487 * Removes the complete netlink message including all
488 * attributes from the socket buffer again. Returns -1.
489 */
490static inline int nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
491{
492 skb_trim(skb, (unsigned char *) nlh - skb->data);
493
494 return -1;
495}
496
497/**
498 * nlmsg_free - free a netlink message
499 * @skb: socket buffer of netlink message
500 */
501static inline void nlmsg_free(struct sk_buff *skb)
502{
503 kfree_skb(skb);
504}
505
506/**
507 * nlmsg_multicast - multicast a netlink message
508 * @sk: netlink socket to spread messages to
509 * @skb: netlink message as socket buffer
510 * @pid: own netlink pid to avoid sending to yourself
511 * @group: multicast group id
512 */
513static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
514 u32 pid, unsigned int group)
515{
516 int err;
517
518 NETLINK_CB(skb).dst_group = group;
519
520 err = netlink_broadcast(sk, skb, pid, group, GFP_KERNEL);
521 if (err > 0)
522 err = 0;
523
524 return err;
525}
526
527/**
528 * nlmsg_unicast - unicast a netlink message
529 * @sk: netlink socket to spread message to
530 * @skb: netlink message as socket buffer
531 * @pid: netlink pid of the destination socket
532 */
533static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid)
534{
535 int err;
536
537 err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT);
538 if (err > 0)
539 err = 0;
540
541 return err;
542}
543
544/**
545 * nlmsg_for_each_msg - iterate over a stream of messages
546 * @pos: loop counter, set to current message
547 * @head: head of message stream
548 * @len: length of message stream
549 * @rem: initialized to len, holds bytes currently remaining in stream
550 */
551#define nlmsg_for_each_msg(pos, head, len, rem) \
552 for (pos = head, rem = len; \
553 nlmsg_ok(pos, rem); \
554 pos = nlmsg_next(pos, &(rem)))
555
556/**************************************************************************
557 * Netlink Attributes
558 **************************************************************************/
559
560/**
561 * nla_attr_size - length of attribute not including padding
562 * @payload: length of payload
563 */
564static inline int nla_attr_size(int payload)
565{
566 return NLA_HDRLEN + payload;
567}
568
569/**
570 * nla_total_size - total length of attribute including padding
571 * @payload: length of payload
572 */
573static inline int nla_total_size(int payload)
574{
575 return NLA_ALIGN(nla_attr_size(payload));
576}
577
578/**
579 * nla_padlen - length of padding at the tail of attribute
580 * @payload: length of payload
581 */
582static inline int nla_padlen(int payload)
583{
584 return nla_total_size(payload) - nla_attr_size(payload);
585}
586
587/**
588 * nla_data - head of payload
589 * @nla: netlink attribute
590 */
591static inline void *nla_data(const struct nlattr *nla)
592{
593 return (char *) nla + NLA_HDRLEN;
594}
595
596/**
597 * nla_len - length of payload
598 * @nla: netlink attribute
599 */
600static inline int nla_len(const struct nlattr *nla)
601{
602 return nla->nla_len - NLA_HDRLEN;
603}
604
605/**
606 * nla_ok - check if the netlink attribute fits into the remaining bytes
607 * @nla: netlink attribute
608 * @remaining: number of bytes remaining in attribute stream
609 */
610static inline int nla_ok(const struct nlattr *nla, int remaining)
611{
612 return remaining >= sizeof(*nla) &&
613 nla->nla_len >= sizeof(*nla) &&
614 nla->nla_len <= remaining;
615}
616
617/**
618 * nla_next - next netlink attribte in attribute stream
619 * @nla: netlink attribute
620 * @remaining: number of bytes remaining in attribute stream
621 *
622 * Returns the next netlink attribute in the attribute stream and
623 * decrements remaining by the size of the current attribute.
624 */
625static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
626{
627 int totlen = NLA_ALIGN(nla->nla_len);
628
629 *remaining -= totlen;
630 return (struct nlattr *) ((char *) nla + totlen);
631}
632
633/**
634 * nla_parse_nested - parse nested attributes
635 * @tb: destination array with maxtype+1 elements
636 * @maxtype: maximum attribute type to be expected
637 * @nla: attribute containing the nested attributes
638 * @policy: validation policy
639 *
640 * See nla_parse()
641 */
642static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
643 struct nlattr *nla,
644 struct nla_policy *policy)
645{
646 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
647}
648/**
649 * nla_put_u8 - Add a u16 netlink attribute to a socket buffer
650 * @skb: socket buffer to add attribute to
651 * @attrtype: attribute type
652 * @value: numeric value
653 */
654static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
655{
656 return nla_put(skb, attrtype, sizeof(u8), &value);
657}
658
659/**
660 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
661 * @skb: socket buffer to add attribute to
662 * @attrtype: attribute type
663 * @value: numeric value
664 */
665static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
666{
667 return nla_put(skb, attrtype, sizeof(u16), &value);
668}
669
670/**
671 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
672 * @skb: socket buffer to add attribute to
673 * @attrtype: attribute type
674 * @value: numeric value
675 */
676static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
677{
678 return nla_put(skb, attrtype, sizeof(u32), &value);
679}
680
681/**
682 * nla_put_64 - Add a u64 netlink attribute to a socket buffer
683 * @skb: socket buffer to add attribute to
684 * @attrtype: attribute type
685 * @value: numeric value
686 */
687static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
688{
689 return nla_put(skb, attrtype, sizeof(u64), &value);
690}
691
692/**
693 * nla_put_string - Add a string netlink attribute to a socket buffer
694 * @skb: socket buffer to add attribute to
695 * @attrtype: attribute type
696 * @str: NUL terminated string
697 */
698static inline int nla_put_string(struct sk_buff *skb, int attrtype,
699 const char *str)
700{
701 return nla_put(skb, attrtype, strlen(str) + 1, str);
702}
703
704/**
705 * nla_put_flag - Add a flag netlink attribute to a socket buffer
706 * @skb: socket buffer to add attribute to
707 * @attrtype: attribute type
708 */
709static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
710{
711 return nla_put(skb, attrtype, 0, NULL);
712}
713
714/**
715 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer
716 * @skb: socket buffer to add attribute to
717 * @attrtype: attribute type
718 * @jiffies: number of msecs in jiffies
719 */
720static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
721 unsigned long jiffies)
722{
723 u64 tmp = jiffies_to_msecs(jiffies);
724 return nla_put(skb, attrtype, sizeof(u64), &tmp);
725}
726
727#define NLA_PUT(skb, attrtype, attrlen, data) \
728 do { \
729 if (nla_put(skb, attrtype, attrlen, data) < 0) \
730 goto nla_put_failure; \
731 } while(0)
732
733#define NLA_PUT_TYPE(skb, type, attrtype, value) \
734 do { \
735 type __tmp = value; \
736 NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \
737 } while(0)
738
739#define NLA_PUT_U8(skb, attrtype, value) \
740 NLA_PUT_TYPE(skb, u8, attrtype, value)
741
742#define NLA_PUT_U16(skb, attrtype, value) \
743 NLA_PUT_TYPE(skb, u16, attrtype, value)
744
745#define NLA_PUT_U32(skb, attrtype, value) \
746 NLA_PUT_TYPE(skb, u32, attrtype, value)
747
748#define NLA_PUT_U64(skb, attrtype, value) \
749 NLA_PUT_TYPE(skb, u64, attrtype, value)
750
751#define NLA_PUT_STRING(skb, attrtype, value) \
752 NLA_PUT(skb, attrtype, strlen(value) + 1, value)
753
754#define NLA_PUT_FLAG(skb, attrtype, value) \
755 NLA_PUT(skb, attrtype, 0, NULL)
756
757#define NLA_PUT_MSECS(skb, attrtype, jiffies) \
758 NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies))
759
760/**
761 * nla_get_u32 - return payload of u32 attribute
762 * @nla: u32 netlink attribute
763 */
764static inline u32 nla_get_u32(struct nlattr *nla)
765{
766 return *(u32 *) nla_data(nla);
767}
768
769/**
770 * nla_get_u16 - return payload of u16 attribute
771 * @nla: u16 netlink attribute
772 */
773static inline u16 nla_get_u16(struct nlattr *nla)
774{
775 return *(u16 *) nla_data(nla);
776}
777
778/**
779 * nla_get_u8 - return payload of u8 attribute
780 * @nla: u8 netlink attribute
781 */
782static inline u8 nla_get_u8(struct nlattr *nla)
783{
784 return *(u8 *) nla_data(nla);
785}
786
787/**
788 * nla_get_u64 - return payload of u64 attribute
789 * @nla: u64 netlink attribute
790 */
791static inline u64 nla_get_u64(struct nlattr *nla)
792{
793 u64 tmp;
794
795 nla_memcpy(&tmp, nla, sizeof(tmp));
796
797 return tmp;
798}
799
800/**
801 * nla_get_flag - return payload of flag attribute
802 * @nla: flag netlink attribute
803 */
804static inline int nla_get_flag(struct nlattr *nla)
805{
806 return !!nla;
807}
808
809/**
810 * nla_get_msecs - return payload of msecs attribute
811 * @nla: msecs netlink attribute
812 *
813 * Returns the number of milliseconds in jiffies.
814 */
815static inline unsigned long nla_get_msecs(struct nlattr *nla)
816{
817 u64 msecs = nla_get_u64(nla);
818
819 return msecs_to_jiffies((unsigned long) msecs);
820}
821
822/**
823 * nla_nest_start - Start a new level of nested attributes
824 * @skb: socket buffer to add attributes to
825 * @attrtype: attribute type of container
826 *
827 * Returns the container attribute
828 */
829static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
830{
831 struct nlattr *start = (struct nlattr *) skb->tail;
832
833 if (nla_put(skb, attrtype, 0, NULL) < 0)
834 return NULL;
835
836 return start;
837}
838
839/**
840 * nla_nest_end - Finalize nesting of attributes
841 * @skb: socket buffer the attribtues are stored in
842 * @start: container attribute
843 *
844 * Corrects the container attribute header to include the all
845 * appeneded attributes.
846 *
847 * Returns the total data length of the skb.
848 */
849static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
850{
851 start->nla_len = skb->tail - (unsigned char *) start;
852 return skb->len;
853}
854
855/**
856 * nla_nest_cancel - Cancel nesting of attributes
857 * @skb: socket buffer the message is stored in
858 * @start: container attribute
859 *
860 * Removes the container attribute and including all nested
861 * attributes. Returns -1.
862 */
863static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
864{
865 if (start)
866 skb_trim(skb, (unsigned char *) start - skb->data);
867
868 return -1;
869}
870
871/**
872 * nla_for_each_attr - iterate over a stream of attributes
873 * @pos: loop counter, set to current attribute
874 * @head: head of attribute stream
875 * @len: length of attribute stream
876 * @rem: initialized to len, holds bytes currently remaining in stream
877 */
878#define nla_for_each_attr(pos, head, len, rem) \
879 for (pos = head, rem = len; \
880 nla_ok(pos, rem); \
881 pos = nla_next(pos, &(rem)))
882
883#endif