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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 | ||
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 | */ | |
151 | enum { | |
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 | */ | |
181 | struct nla_policy { | |
182 | u16 type; | |
183 | u16 minlen; | |
184 | }; | |
185 | ||
186 | extern int nla_validate(struct nlattr *head, int len, int maxtype, | |
187 | struct nla_policy *policy); | |
188 | extern int nla_parse(struct nlattr *tb[], int maxtype, | |
189 | struct nlattr *head, int len, | |
190 | struct nla_policy *policy); | |
191 | extern struct nlattr * nla_find(struct nlattr *head, int len, int attrtype); | |
192 | extern size_t nla_strlcpy(char *dst, const struct nlattr *nla, | |
193 | size_t dstsize); | |
194 | extern int nla_memcpy(void *dest, struct nlattr *src, int count); | |
195 | extern int nla_memcmp(const struct nlattr *nla, const void *data, | |
196 | size_t size); | |
197 | extern int nla_strcmp(const struct nlattr *nla, const char *str); | |
198 | extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype, | |
199 | int attrlen); | |
200 | extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype, | |
201 | int attrlen); | |
202 | extern void __nla_put(struct sk_buff *skb, int attrtype, | |
203 | int attrlen, const void *data); | |
204 | extern int nla_put(struct sk_buff *skb, int attrtype, | |
205 | int attrlen, const void *data); | |
206 | ||
207 | /************************************************************************** | |
208 | * Netlink Messages | |
209 | **************************************************************************/ | |
210 | ||
211 | /** | |
212 | * nlmsg_msg_size - length of netlink message not including padding | |
213 | * @payload: length of message payload | |
214 | */ | |
215 | static inline int nlmsg_msg_size(int payload) | |
216 | { | |
217 | return NLMSG_HDRLEN + payload; | |
218 | } | |
219 | ||
220 | /** | |
221 | * nlmsg_total_size - length of netlink message including padding | |
222 | * @payload: length of message payload | |
223 | */ | |
224 | static inline int nlmsg_total_size(int payload) | |
225 | { | |
226 | return NLMSG_ALIGN(nlmsg_msg_size(payload)); | |
227 | } | |
228 | ||
229 | /** | |
230 | * nlmsg_padlen - length of padding at the message's tail | |
231 | * @payload: length of message payload | |
232 | */ | |
233 | static inline int nlmsg_padlen(int payload) | |
234 | { | |
235 | return nlmsg_total_size(payload) - nlmsg_msg_size(payload); | |
236 | } | |
237 | ||
238 | /** | |
239 | * nlmsg_data - head of message payload | |
240 | * @nlh: netlink messsage header | |
241 | */ | |
242 | static inline void *nlmsg_data(const struct nlmsghdr *nlh) | |
243 | { | |
244 | return (unsigned char *) nlh + NLMSG_HDRLEN; | |
245 | } | |
246 | ||
247 | /** | |
248 | * nlmsg_len - length of message payload | |
249 | * @nlh: netlink message header | |
250 | */ | |
251 | static inline int nlmsg_len(const struct nlmsghdr *nlh) | |
252 | { | |
253 | return nlh->nlmsg_len - NLMSG_HDRLEN; | |
254 | } | |
255 | ||
256 | /** | |
257 | * nlmsg_attrdata - head of attributes data | |
258 | * @nlh: netlink message header | |
259 | * @hdrlen: length of family specific header | |
260 | */ | |
261 | static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, | |
262 | int hdrlen) | |
263 | { | |
264 | unsigned char *data = nlmsg_data(nlh); | |
265 | return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); | |
266 | } | |
267 | ||
268 | /** | |
269 | * nlmsg_attrlen - length of attributes data | |
270 | * @nlh: netlink message header | |
271 | * @hdrlen: length of family specific header | |
272 | */ | |
273 | static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) | |
274 | { | |
275 | return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); | |
276 | } | |
277 | ||
278 | /** | |
279 | * nlmsg_ok - check if the netlink message fits into the remaining bytes | |
280 | * @nlh: netlink message header | |
281 | * @remaining: number of bytes remaining in message stream | |
282 | */ | |
283 | static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) | |
284 | { | |
285 | return (remaining >= sizeof(struct nlmsghdr) && | |
286 | nlh->nlmsg_len >= sizeof(struct nlmsghdr) && | |
287 | nlh->nlmsg_len <= remaining); | |
288 | } | |
289 | ||
290 | /** | |
291 | * nlmsg_next - next netlink message in message stream | |
292 | * @nlh: netlink message header | |
293 | * @remaining: number of bytes remaining in message stream | |
294 | * | |
295 | * Returns the next netlink message in the message stream and | |
296 | * decrements remaining by the size of the current message. | |
297 | */ | |
298 | static inline struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining) | |
299 | { | |
300 | int totlen = NLMSG_ALIGN(nlh->nlmsg_len); | |
301 | ||
302 | *remaining -= totlen; | |
303 | ||
304 | return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); | |
305 | } | |
306 | ||
307 | /** | |
308 | * nlmsg_parse - parse attributes of a netlink message | |
309 | * @nlh: netlink message header | |
310 | * @hdrlen: length of family specific header | |
311 | * @tb: destination array with maxtype+1 elements | |
312 | * @maxtype: maximum attribute type to be expected | |
313 | * @policy: validation policy | |
314 | * | |
315 | * See nla_parse() | |
316 | */ | |
317 | static inline int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen, | |
318 | struct nlattr *tb[], int maxtype, | |
319 | struct nla_policy *policy) | |
320 | { | |
321 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | |
322 | return -EINVAL; | |
323 | ||
324 | return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), | |
325 | nlmsg_attrlen(nlh, hdrlen), policy); | |
326 | } | |
327 | ||
328 | /** | |
329 | * nlmsg_find_attr - find a specific attribute in a netlink message | |
330 | * @nlh: netlink message header | |
331 | * @hdrlen: length of familiy specific header | |
332 | * @attrtype: type of attribute to look for | |
333 | * | |
334 | * Returns the first attribute which matches the specified type. | |
335 | */ | |
336 | static inline struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh, | |
337 | int hdrlen, int attrtype) | |
338 | { | |
339 | return nla_find(nlmsg_attrdata(nlh, hdrlen), | |
340 | nlmsg_attrlen(nlh, hdrlen), attrtype); | |
341 | } | |
342 | ||
343 | /** | |
344 | * nlmsg_validate - validate a netlink message including attributes | |
345 | * @nlh: netlinket message header | |
346 | * @hdrlen: length of familiy specific header | |
347 | * @maxtype: maximum attribute type to be expected | |
348 | * @policy: validation policy | |
349 | */ | |
350 | static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype, | |
351 | struct nla_policy *policy) | |
352 | { | |
353 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | |
354 | return -EINVAL; | |
355 | ||
356 | return nla_validate(nlmsg_attrdata(nlh, hdrlen), | |
357 | nlmsg_attrlen(nlh, hdrlen), maxtype, policy); | |
358 | } | |
359 | ||
360 | /** | |
361 | * nlmsg_for_each_attr - iterate over a stream of attributes | |
362 | * @pos: loop counter, set to current attribute | |
363 | * @nlh: netlink message header | |
364 | * @hdrlen: length of familiy specific header | |
365 | * @rem: initialized to len, holds bytes currently remaining in stream | |
366 | */ | |
367 | #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ | |
368 | nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ | |
369 | nlmsg_attrlen(nlh, hdrlen), rem) | |
370 | ||
371 | #if 0 | |
372 | /* FIXME: Enable once all users have been converted */ | |
373 | ||
374 | /** | |
375 | * __nlmsg_put - Add a new netlink message to an skb | |
376 | * @skb: socket buffer to store message in | |
377 | * @pid: netlink process id | |
378 | * @seq: sequence number of message | |
379 | * @type: message type | |
380 | * @payload: length of message payload | |
381 | * @flags: message flags | |
382 | * | |
383 | * The caller is responsible to ensure that the skb provides enough | |
384 | * tailroom for both the netlink header and payload. | |
385 | */ | |
386 | static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid, | |
387 | u32 seq, int type, int payload, | |
388 | int flags) | |
389 | { | |
390 | struct nlmsghdr *nlh; | |
391 | ||
392 | nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload)); | |
393 | nlh->nlmsg_type = type; | |
394 | nlh->nlmsg_len = nlmsg_msg_size(payload); | |
395 | nlh->nlmsg_flags = flags; | |
396 | nlh->nlmsg_pid = pid; | |
397 | nlh->nlmsg_seq = seq; | |
398 | ||
399 | memset((unsigned char *) nlmsg_data(nlh) + payload, 0, | |
400 | nlmsg_padlen(payload)); | |
401 | ||
402 | return nlh; | |
403 | } | |
404 | #endif | |
405 | ||
406 | /** | |
407 | * nlmsg_put - Add a new netlink message to an skb | |
408 | * @skb: socket buffer to store message in | |
409 | * @pid: netlink process id | |
410 | * @seq: sequence number of message | |
411 | * @type: message type | |
412 | * @payload: length of message payload | |
413 | * @flags: message flags | |
414 | * | |
415 | * Returns NULL if the tailroom of the skb is insufficient to store | |
416 | * the message header and payload. | |
417 | */ | |
418 | static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, | |
419 | int type, int payload, int flags) | |
420 | { | |
421 | if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) | |
422 | return NULL; | |
423 | ||
424 | return __nlmsg_put(skb, pid, seq, type, payload, flags); | |
425 | } | |
426 | ||
427 | /** | |
428 | * nlmsg_put_answer - Add a new callback based netlink message to an skb | |
429 | * @skb: socket buffer to store message in | |
430 | * @cb: netlink callback | |
431 | * @type: message type | |
432 | * @payload: length of message payload | |
433 | * @flags: message flags | |
434 | * | |
435 | * Returns NULL if the tailroom of the skb is insufficient to store | |
436 | * the message header and payload. | |
437 | */ | |
438 | static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, | |
439 | struct netlink_callback *cb, | |
440 | int type, int payload, | |
441 | int flags) | |
442 | { | |
443 | return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, | |
444 | type, payload, flags); | |
445 | } | |
446 | ||
447 | /** | |
448 | * nlmsg_new - Allocate a new netlink message | |
449 | * @size: maximum size of message | |
450 | * | |
451 | * Use NLMSG_GOODSIZE if size isn't know and you need a good default size. | |
452 | */ | |
453 | static inline struct sk_buff *nlmsg_new(int size) | |
454 | { | |
455 | return alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); | |
456 | } | |
457 | ||
458 | /** | |
459 | * nlmsg_end - Finalize a netlink message | |
460 | * @skb: socket buffer the message is stored in | |
461 | * @nlh: netlink message header | |
462 | * | |
463 | * Corrects the netlink message header to include the appeneded | |
464 | * attributes. Only necessary if attributes have been added to | |
465 | * the message. | |
466 | * | |
467 | * Returns the total data length of the skb. | |
468 | */ | |
469 | static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) | |
470 | { | |
471 | nlh->nlmsg_len = skb->tail - (unsigned char *) nlh; | |
472 | ||
473 | return skb->len; | |
474 | } | |
475 | ||
476 | /** | |
477 | * nlmsg_cancel - Cancel construction of a netlink message | |
478 | * @skb: socket buffer the message is stored in | |
479 | * @nlh: netlink message header | |
480 | * | |
481 | * Removes the complete netlink message including all | |
482 | * attributes from the socket buffer again. Returns -1. | |
483 | */ | |
484 | static inline int nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) | |
485 | { | |
486 | skb_trim(skb, (unsigned char *) nlh - skb->data); | |
487 | ||
488 | return -1; | |
489 | } | |
490 | ||
491 | /** | |
492 | * nlmsg_free - free a netlink message | |
493 | * @skb: socket buffer of netlink message | |
494 | */ | |
495 | static inline void nlmsg_free(struct sk_buff *skb) | |
496 | { | |
497 | kfree_skb(skb); | |
498 | } | |
499 | ||
500 | /** | |
501 | * nlmsg_multicast - multicast a netlink message | |
502 | * @sk: netlink socket to spread messages to | |
503 | * @skb: netlink message as socket buffer | |
504 | * @pid: own netlink pid to avoid sending to yourself | |
505 | * @group: multicast group id | |
506 | */ | |
507 | static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, | |
508 | u32 pid, unsigned int group) | |
509 | { | |
510 | int err; | |
511 | ||
512 | NETLINK_CB(skb).dst_group = group; | |
513 | ||
514 | err = netlink_broadcast(sk, skb, pid, group, GFP_KERNEL); | |
515 | if (err > 0) | |
516 | err = 0; | |
517 | ||
518 | return err; | |
519 | } | |
520 | ||
521 | /** | |
522 | * nlmsg_unicast - unicast a netlink message | |
523 | * @sk: netlink socket to spread message to | |
524 | * @skb: netlink message as socket buffer | |
525 | * @pid: netlink pid of the destination socket | |
526 | */ | |
527 | static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid) | |
528 | { | |
529 | int err; | |
530 | ||
531 | err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT); | |
532 | if (err > 0) | |
533 | err = 0; | |
534 | ||
535 | return err; | |
536 | } | |
537 | ||
538 | /** | |
539 | * nlmsg_for_each_msg - iterate over a stream of messages | |
540 | * @pos: loop counter, set to current message | |
541 | * @head: head of message stream | |
542 | * @len: length of message stream | |
543 | * @rem: initialized to len, holds bytes currently remaining in stream | |
544 | */ | |
545 | #define nlmsg_for_each_msg(pos, head, len, rem) \ | |
546 | for (pos = head, rem = len; \ | |
547 | nlmsg_ok(pos, rem); \ | |
548 | pos = nlmsg_next(pos, &(rem))) | |
549 | ||
550 | /************************************************************************** | |
551 | * Netlink Attributes | |
552 | **************************************************************************/ | |
553 | ||
554 | /** | |
555 | * nla_attr_size - length of attribute not including padding | |
556 | * @payload: length of payload | |
557 | */ | |
558 | static inline int nla_attr_size(int payload) | |
559 | { | |
560 | return NLA_HDRLEN + payload; | |
561 | } | |
562 | ||
563 | /** | |
564 | * nla_total_size - total length of attribute including padding | |
565 | * @payload: length of payload | |
566 | */ | |
567 | static inline int nla_total_size(int payload) | |
568 | { | |
569 | return NLA_ALIGN(nla_attr_size(payload)); | |
570 | } | |
571 | ||
572 | /** | |
573 | * nla_padlen - length of padding at the tail of attribute | |
574 | * @payload: length of payload | |
575 | */ | |
576 | static inline int nla_padlen(int payload) | |
577 | { | |
578 | return nla_total_size(payload) - nla_attr_size(payload); | |
579 | } | |
580 | ||
581 | /** | |
582 | * nla_data - head of payload | |
583 | * @nla: netlink attribute | |
584 | */ | |
585 | static inline void *nla_data(const struct nlattr *nla) | |
586 | { | |
587 | return (char *) nla + NLA_HDRLEN; | |
588 | } | |
589 | ||
590 | /** | |
591 | * nla_len - length of payload | |
592 | * @nla: netlink attribute | |
593 | */ | |
594 | static inline int nla_len(const struct nlattr *nla) | |
595 | { | |
596 | return nla->nla_len - NLA_HDRLEN; | |
597 | } | |
598 | ||
599 | /** | |
600 | * nla_ok - check if the netlink attribute fits into the remaining bytes | |
601 | * @nla: netlink attribute | |
602 | * @remaining: number of bytes remaining in attribute stream | |
603 | */ | |
604 | static inline int nla_ok(const struct nlattr *nla, int remaining) | |
605 | { | |
606 | return remaining >= sizeof(*nla) && | |
607 | nla->nla_len >= sizeof(*nla) && | |
608 | nla->nla_len <= remaining; | |
609 | } | |
610 | ||
611 | /** | |
612 | * nla_next - next netlink attribte in attribute stream | |
613 | * @nla: netlink attribute | |
614 | * @remaining: number of bytes remaining in attribute stream | |
615 | * | |
616 | * Returns the next netlink attribute in the attribute stream and | |
617 | * decrements remaining by the size of the current attribute. | |
618 | */ | |
619 | static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) | |
620 | { | |
621 | int totlen = NLA_ALIGN(nla->nla_len); | |
622 | ||
623 | *remaining -= totlen; | |
624 | return (struct nlattr *) ((char *) nla + totlen); | |
625 | } | |
626 | ||
627 | /** | |
628 | * nla_parse_nested - parse nested attributes | |
629 | * @tb: destination array with maxtype+1 elements | |
630 | * @maxtype: maximum attribute type to be expected | |
631 | * @nla: attribute containing the nested attributes | |
632 | * @policy: validation policy | |
633 | * | |
634 | * See nla_parse() | |
635 | */ | |
636 | static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, | |
637 | struct nlattr *nla, | |
638 | struct nla_policy *policy) | |
639 | { | |
640 | return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); | |
641 | } | |
642 | /** | |
643 | * nla_put_u8 - Add a u16 netlink attribute to a socket buffer | |
644 | * @skb: socket buffer to add attribute to | |
645 | * @attrtype: attribute type | |
646 | * @value: numeric value | |
647 | */ | |
648 | static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) | |
649 | { | |
650 | return nla_put(skb, attrtype, sizeof(u8), &value); | |
651 | } | |
652 | ||
653 | /** | |
654 | * nla_put_u16 - Add a u16 netlink attribute to a socket buffer | |
655 | * @skb: socket buffer to add attribute to | |
656 | * @attrtype: attribute type | |
657 | * @value: numeric value | |
658 | */ | |
659 | static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) | |
660 | { | |
661 | return nla_put(skb, attrtype, sizeof(u16), &value); | |
662 | } | |
663 | ||
664 | /** | |
665 | * nla_put_u32 - Add a u32 netlink attribute to a socket buffer | |
666 | * @skb: socket buffer to add attribute to | |
667 | * @attrtype: attribute type | |
668 | * @value: numeric value | |
669 | */ | |
670 | static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) | |
671 | { | |
672 | return nla_put(skb, attrtype, sizeof(u32), &value); | |
673 | } | |
674 | ||
675 | /** | |
676 | * nla_put_64 - Add a u64 netlink attribute to a socket buffer | |
677 | * @skb: socket buffer to add attribute to | |
678 | * @attrtype: attribute type | |
679 | * @value: numeric value | |
680 | */ | |
681 | static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value) | |
682 | { | |
683 | return nla_put(skb, attrtype, sizeof(u64), &value); | |
684 | } | |
685 | ||
686 | /** | |
687 | * nla_put_string - Add a string netlink attribute to a socket buffer | |
688 | * @skb: socket buffer to add attribute to | |
689 | * @attrtype: attribute type | |
690 | * @str: NUL terminated string | |
691 | */ | |
692 | static inline int nla_put_string(struct sk_buff *skb, int attrtype, | |
693 | const char *str) | |
694 | { | |
695 | return nla_put(skb, attrtype, strlen(str) + 1, str); | |
696 | } | |
697 | ||
698 | /** | |
699 | * nla_put_flag - Add a flag netlink attribute to a socket buffer | |
700 | * @skb: socket buffer to add attribute to | |
701 | * @attrtype: attribute type | |
702 | */ | |
703 | static inline int nla_put_flag(struct sk_buff *skb, int attrtype) | |
704 | { | |
705 | return nla_put(skb, attrtype, 0, NULL); | |
706 | } | |
707 | ||
708 | /** | |
709 | * nla_put_msecs - Add a msecs netlink attribute to a socket buffer | |
710 | * @skb: socket buffer to add attribute to | |
711 | * @attrtype: attribute type | |
712 | * @jiffies: number of msecs in jiffies | |
713 | */ | |
714 | static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, | |
715 | unsigned long jiffies) | |
716 | { | |
717 | u64 tmp = jiffies_to_msecs(jiffies); | |
718 | return nla_put(skb, attrtype, sizeof(u64), &tmp); | |
719 | } | |
720 | ||
721 | #define NLA_PUT(skb, attrtype, attrlen, data) \ | |
722 | do { \ | |
723 | if (nla_put(skb, attrtype, attrlen, data) < 0) \ | |
724 | goto nla_put_failure; \ | |
725 | } while(0) | |
726 | ||
727 | #define NLA_PUT_TYPE(skb, type, attrtype, value) \ | |
728 | do { \ | |
729 | type __tmp = value; \ | |
730 | NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \ | |
731 | } while(0) | |
732 | ||
733 | #define NLA_PUT_U8(skb, attrtype, value) \ | |
734 | NLA_PUT_TYPE(skb, u8, attrtype, value) | |
735 | ||
736 | #define NLA_PUT_U16(skb, attrtype, value) \ | |
737 | NLA_PUT_TYPE(skb, u16, attrtype, value) | |
738 | ||
739 | #define NLA_PUT_U32(skb, attrtype, value) \ | |
740 | NLA_PUT_TYPE(skb, u32, attrtype, value) | |
741 | ||
742 | #define NLA_PUT_U64(skb, attrtype, value) \ | |
743 | NLA_PUT_TYPE(skb, u64, attrtype, value) | |
744 | ||
745 | #define NLA_PUT_STRING(skb, attrtype, value) \ | |
746 | NLA_PUT(skb, attrtype, strlen(value) + 1, value) | |
747 | ||
748 | #define NLA_PUT_FLAG(skb, attrtype, value) \ | |
749 | NLA_PUT(skb, attrtype, 0, NULL) | |
750 | ||
751 | #define NLA_PUT_MSECS(skb, attrtype, jiffies) \ | |
752 | NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies)) | |
753 | ||
754 | /** | |
755 | * nla_get_u32 - return payload of u32 attribute | |
756 | * @nla: u32 netlink attribute | |
757 | */ | |
758 | static inline u32 nla_get_u32(struct nlattr *nla) | |
759 | { | |
760 | return *(u32 *) nla_data(nla); | |
761 | } | |
762 | ||
763 | /** | |
764 | * nla_get_u16 - return payload of u16 attribute | |
765 | * @nla: u16 netlink attribute | |
766 | */ | |
767 | static inline u16 nla_get_u16(struct nlattr *nla) | |
768 | { | |
769 | return *(u16 *) nla_data(nla); | |
770 | } | |
771 | ||
772 | /** | |
773 | * nla_get_u8 - return payload of u8 attribute | |
774 | * @nla: u8 netlink attribute | |
775 | */ | |
776 | static inline u8 nla_get_u8(struct nlattr *nla) | |
777 | { | |
778 | return *(u8 *) nla_data(nla); | |
779 | } | |
780 | ||
781 | /** | |
782 | * nla_get_u64 - return payload of u64 attribute | |
783 | * @nla: u64 netlink attribute | |
784 | */ | |
785 | static inline u64 nla_get_u64(struct nlattr *nla) | |
786 | { | |
787 | u64 tmp; | |
788 | ||
789 | nla_memcpy(&tmp, nla, sizeof(tmp)); | |
790 | ||
791 | return tmp; | |
792 | } | |
793 | ||
794 | /** | |
795 | * nla_get_flag - return payload of flag attribute | |
796 | * @nla: flag netlink attribute | |
797 | */ | |
798 | static inline int nla_get_flag(struct nlattr *nla) | |
799 | { | |
800 | return !!nla; | |
801 | } | |
802 | ||
803 | /** | |
804 | * nla_get_msecs - return payload of msecs attribute | |
805 | * @nla: msecs netlink attribute | |
806 | * | |
807 | * Returns the number of milliseconds in jiffies. | |
808 | */ | |
809 | static inline unsigned long nla_get_msecs(struct nlattr *nla) | |
810 | { | |
811 | u64 msecs = nla_get_u64(nla); | |
812 | ||
813 | return msecs_to_jiffies((unsigned long) msecs); | |
814 | } | |
815 | ||
816 | /** | |
817 | * nla_nest_start - Start a new level of nested attributes | |
818 | * @skb: socket buffer to add attributes to | |
819 | * @attrtype: attribute type of container | |
820 | * | |
821 | * Returns the container attribute | |
822 | */ | |
823 | static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) | |
824 | { | |
825 | struct nlattr *start = (struct nlattr *) skb->tail; | |
826 | ||
827 | if (nla_put(skb, attrtype, 0, NULL) < 0) | |
828 | return NULL; | |
829 | ||
830 | return start; | |
831 | } | |
832 | ||
833 | /** | |
834 | * nla_nest_end - Finalize nesting of attributes | |
835 | * @skb: socket buffer the attribtues are stored in | |
836 | * @start: container attribute | |
837 | * | |
838 | * Corrects the container attribute header to include the all | |
839 | * appeneded attributes. | |
840 | * | |
841 | * Returns the total data length of the skb. | |
842 | */ | |
843 | static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) | |
844 | { | |
845 | start->nla_len = skb->tail - (unsigned char *) start; | |
846 | return skb->len; | |
847 | } | |
848 | ||
849 | /** | |
850 | * nla_nest_cancel - Cancel nesting of attributes | |
851 | * @skb: socket buffer the message is stored in | |
852 | * @start: container attribute | |
853 | * | |
854 | * Removes the container attribute and including all nested | |
855 | * attributes. Returns -1. | |
856 | */ | |
857 | static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) | |
858 | { | |
859 | if (start) | |
860 | skb_trim(skb, (unsigned char *) start - skb->data); | |
861 | ||
862 | return -1; | |
863 | } | |
864 | ||
865 | /** | |
866 | * nla_for_each_attr - iterate over a stream of attributes | |
867 | * @pos: loop counter, set to current attribute | |
868 | * @head: head of attribute stream | |
869 | * @len: length of attribute stream | |
870 | * @rem: initialized to len, holds bytes currently remaining in stream | |
871 | */ | |
872 | #define nla_for_each_attr(pos, head, len, rem) \ | |
873 | for (pos = head, rem = len; \ | |
874 | nla_ok(pos, rem); \ | |
875 | pos = nla_next(pos, &(rem))) | |
876 | ||
877 | #endif |