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bfa83a9e TG |
1 | #ifndef __NET_NETLINK_H |
2 | #define __NET_NETLINK_H | |
3 | ||
4 | #include <linux/types.h> | |
5 | #include <linux/netlink.h> | |
d7fe0f24 | 6 | #include <linux/jiffies.h> |
bfa83a9e TG |
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() finanlize netlink message | |
fe4944e5 TG |
39 | * nlmsg_get_pos() return current position in message |
40 | * nlmsg_trim() trim part of message | |
bfa83a9e TG |
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 | |
d387f6ad | 47 | * nlmsg_notify() send notification message |
bfa83a9e TG |
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 | * | |
97676b6b TG |
69 | * Misc: |
70 | * nlmsg_report() report back to application? | |
71 | * | |
bfa83a9e TG |
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 attribtue header | |
88 | * | |
89 | * Attribute Construction: | |
fe4944e5 TG |
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 | |
bfa83a9e | 92 | * nla_put(skb, type, len, data) add attribute to skb |
fe4944e5 | 93 | * nla_put_nohdr(skb, len, data) add attribute w/o hdr |
bfa83a9e TG |
94 | * |
95 | * Attribute Construction for Basic Types: | |
96 | * nla_put_u8(skb, type, value) add u8 attribute to skb | |
97 | * nla_put_u16(skb, type, value) add u16 attribute to skb | |
98 | * nla_put_u32(skb, type, value) add u32 attribute to skb | |
99 | * nla_put_u64(skb, type, value) add u64 attribute to skb | |
100 | * nla_put_string(skb, type, str) add string attribute to skb | |
101 | * nla_put_flag(skb, type) add flag attribute to skb | |
102 | * nla_put_msecs(skb, type, jiffies) add msecs attribute to skb | |
103 | * | |
104 | * Exceptions Based Attribute Construction: | |
105 | * NLA_PUT(skb, type, len, data) add attribute to skb | |
106 | * NLA_PUT_U8(skb, type, value) add u8 attribute to skb | |
107 | * NLA_PUT_U16(skb, type, value) add u16 attribute to skb | |
108 | * NLA_PUT_U32(skb, type, value) add u32 attribute to skb | |
109 | * NLA_PUT_U64(skb, type, value) add u64 attribute to skb | |
110 | * NLA_PUT_STRING(skb, type, str) add string attribute to skb | |
111 | * NLA_PUT_FLAG(skb, type) add flag attribute to skb | |
112 | * NLA_PUT_MSECS(skb, type, jiffies) add msecs attribute to skb | |
113 | * | |
114 | * The meaning of these functions is equal to their lower case | |
115 | * variants but they jump to the label nla_put_failure in case | |
116 | * of a failure. | |
117 | * | |
118 | * Nested Attributes Construction: | |
119 | * nla_nest_start(skb, type) start a nested attribute | |
120 | * nla_nest_end(skb, nla) finalize a nested attribute | |
121 | * nla_nest_cancel(skb, nla) cancel nested attribute construction | |
122 | * | |
123 | * Attribute Length Calculations: | |
124 | * nla_attr_size(payload) length of attribute w/o padding | |
125 | * nla_total_size(payload) length of attribute w/ padding | |
126 | * nla_padlen(payload) length of padding | |
127 | * | |
128 | * Attribute Payload Access: | |
129 | * nla_data(nla) head of attribute payload | |
130 | * nla_len(nla) length of attribute payload | |
131 | * | |
132 | * Attribute Payload Access for Basic Types: | |
133 | * nla_get_u8(nla) get payload for a u8 attribute | |
134 | * nla_get_u16(nla) get payload for a u16 attribute | |
135 | * nla_get_u32(nla) get payload for a u32 attribute | |
136 | * nla_get_u64(nla) get payload for a u64 attribute | |
137 | * nla_get_flag(nla) return 1 if flag is true | |
138 | * nla_get_msecs(nla) get payload for a msecs attribute | |
139 | * | |
140 | * Attribute Misc: | |
141 | * nla_memcpy(dest, nla, count) copy attribute into memory | |
142 | * nla_memcmp(nla, data, size) compare attribute with memory area | |
143 | * nla_strlcpy(dst, nla, size) copy attribute to a sized string | |
144 | * nla_strcmp(nla, str) compare attribute with string | |
145 | * | |
146 | * Attribute Parsing: | |
147 | * nla_ok(nla, remaining) does nla fit into remaining bytes? | |
148 | * nla_next(nla, remaining) get next netlink attribute | |
149 | * nla_validate() validate a stream of attributes | |
4fe5d5c0 | 150 | * nla_validate_nested() validate a stream of nested attributes |
bfa83a9e | 151 | * nla_find() find attribute in stream of attributes |
fe4944e5 | 152 | * nla_find_nested() find attribute in nested attributes |
bfa83a9e TG |
153 | * nla_parse() parse and validate stream of attrs |
154 | * nla_parse_nested() parse nested attribuets | |
155 | * nla_for_each_attr() loop over all attributes | |
22acb19a | 156 | * nla_for_each_nested() loop over the nested attributes |
bfa83a9e TG |
157 | *========================================================================= |
158 | */ | |
159 | ||
160 | /** | |
161 | * Standard attribute types to specify validation policy | |
162 | */ | |
163 | enum { | |
164 | NLA_UNSPEC, | |
165 | NLA_U8, | |
166 | NLA_U16, | |
167 | NLA_U32, | |
168 | NLA_U64, | |
169 | NLA_STRING, | |
170 | NLA_FLAG, | |
171 | NLA_MSECS, | |
172 | NLA_NESTED, | |
a5531a5d | 173 | NLA_NUL_STRING, |
d30045a0 | 174 | NLA_BINARY, |
bfa83a9e TG |
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 | |
a5531a5d | 183 | * @len: Type specific length of payload |
bfa83a9e TG |
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 | * | |
a5531a5d TG |
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 | |
d30045a0 | 192 | * NLA_BINARY Maximum length of attribute payload |
a5531a5d TG |
193 | * All other Exact length of attribute payload |
194 | * | |
bfa83a9e TG |
195 | * Example: |
196 | * static struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = { | |
197 | * [ATTR_FOO] = { .type = NLA_U16 }, | |
d30045a0 | 198 | * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, |
a5531a5d | 199 | * [ATTR_BAZ] = { .len = sizeof(struct mystruct) }, |
bfa83a9e TG |
200 | * }; |
201 | */ | |
202 | struct nla_policy { | |
203 | u16 type; | |
a5531a5d | 204 | u16 len; |
bfa83a9e TG |
205 | }; |
206 | ||
4e902c57 TG |
207 | /** |
208 | * struct nl_info - netlink source information | |
209 | * @nlh: Netlink message header of original request | |
210 | * @pid: Netlink PID of requesting application | |
211 | */ | |
212 | struct nl_info { | |
213 | struct nlmsghdr *nlh; | |
214 | u32 pid; | |
215 | }; | |
216 | ||
82ace47a TG |
217 | extern void netlink_run_queue(struct sock *sk, unsigned int *qlen, |
218 | int (*cb)(struct sk_buff *, | |
1d00a4eb | 219 | struct nlmsghdr *)); |
82ace47a TG |
220 | extern void netlink_queue_skip(struct nlmsghdr *nlh, |
221 | struct sk_buff *skb); | |
97676b6b TG |
222 | extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb, |
223 | u32 pid, unsigned int group, int report, | |
224 | gfp_t flags); | |
82ace47a | 225 | |
bfa83a9e TG |
226 | extern int nla_validate(struct nlattr *head, int len, int maxtype, |
227 | struct nla_policy *policy); | |
228 | extern int nla_parse(struct nlattr *tb[], int maxtype, | |
229 | struct nlattr *head, int len, | |
230 | struct nla_policy *policy); | |
231 | extern struct nlattr * nla_find(struct nlattr *head, int len, int attrtype); | |
232 | extern size_t nla_strlcpy(char *dst, const struct nlattr *nla, | |
233 | size_t dstsize); | |
234 | extern int nla_memcpy(void *dest, struct nlattr *src, int count); | |
235 | extern int nla_memcmp(const struct nlattr *nla, const void *data, | |
236 | size_t size); | |
237 | extern int nla_strcmp(const struct nlattr *nla, const char *str); | |
238 | extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype, | |
239 | int attrlen); | |
fe4944e5 | 240 | extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen); |
bfa83a9e TG |
241 | extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype, |
242 | int attrlen); | |
fe4944e5 | 243 | extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen); |
bfa83a9e TG |
244 | extern void __nla_put(struct sk_buff *skb, int attrtype, |
245 | int attrlen, const void *data); | |
fe4944e5 TG |
246 | extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen, |
247 | const void *data); | |
bfa83a9e TG |
248 | extern int nla_put(struct sk_buff *skb, int attrtype, |
249 | int attrlen, const void *data); | |
fe4944e5 TG |
250 | extern int nla_put_nohdr(struct sk_buff *skb, int attrlen, |
251 | const void *data); | |
bfa83a9e TG |
252 | |
253 | /************************************************************************** | |
254 | * Netlink Messages | |
255 | **************************************************************************/ | |
256 | ||
257 | /** | |
258 | * nlmsg_msg_size - length of netlink message not including padding | |
259 | * @payload: length of message payload | |
260 | */ | |
261 | static inline int nlmsg_msg_size(int payload) | |
262 | { | |
263 | return NLMSG_HDRLEN + payload; | |
264 | } | |
265 | ||
266 | /** | |
267 | * nlmsg_total_size - length of netlink message including padding | |
268 | * @payload: length of message payload | |
269 | */ | |
270 | static inline int nlmsg_total_size(int payload) | |
271 | { | |
272 | return NLMSG_ALIGN(nlmsg_msg_size(payload)); | |
273 | } | |
274 | ||
275 | /** | |
276 | * nlmsg_padlen - length of padding at the message's tail | |
277 | * @payload: length of message payload | |
278 | */ | |
279 | static inline int nlmsg_padlen(int payload) | |
280 | { | |
281 | return nlmsg_total_size(payload) - nlmsg_msg_size(payload); | |
282 | } | |
283 | ||
284 | /** | |
285 | * nlmsg_data - head of message payload | |
286 | * @nlh: netlink messsage header | |
287 | */ | |
288 | static inline void *nlmsg_data(const struct nlmsghdr *nlh) | |
289 | { | |
290 | return (unsigned char *) nlh + NLMSG_HDRLEN; | |
291 | } | |
292 | ||
293 | /** | |
294 | * nlmsg_len - length of message payload | |
295 | * @nlh: netlink message header | |
296 | */ | |
297 | static inline int nlmsg_len(const struct nlmsghdr *nlh) | |
298 | { | |
299 | return nlh->nlmsg_len - NLMSG_HDRLEN; | |
300 | } | |
301 | ||
302 | /** | |
303 | * nlmsg_attrdata - head of attributes data | |
304 | * @nlh: netlink message header | |
305 | * @hdrlen: length of family specific header | |
306 | */ | |
307 | static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, | |
308 | int hdrlen) | |
309 | { | |
310 | unsigned char *data = nlmsg_data(nlh); | |
311 | return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); | |
312 | } | |
313 | ||
314 | /** | |
315 | * nlmsg_attrlen - length of attributes data | |
316 | * @nlh: netlink message header | |
317 | * @hdrlen: length of family specific header | |
318 | */ | |
319 | static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) | |
320 | { | |
321 | return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); | |
322 | } | |
323 | ||
324 | /** | |
325 | * nlmsg_ok - check if the netlink message fits into the remaining bytes | |
326 | * @nlh: netlink message header | |
327 | * @remaining: number of bytes remaining in message stream | |
328 | */ | |
329 | static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) | |
330 | { | |
331 | return (remaining >= sizeof(struct nlmsghdr) && | |
332 | nlh->nlmsg_len >= sizeof(struct nlmsghdr) && | |
333 | nlh->nlmsg_len <= remaining); | |
334 | } | |
335 | ||
336 | /** | |
337 | * nlmsg_next - next netlink message in message stream | |
338 | * @nlh: netlink message header | |
339 | * @remaining: number of bytes remaining in message stream | |
340 | * | |
341 | * Returns the next netlink message in the message stream and | |
342 | * decrements remaining by the size of the current message. | |
343 | */ | |
344 | static inline struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining) | |
345 | { | |
346 | int totlen = NLMSG_ALIGN(nlh->nlmsg_len); | |
347 | ||
348 | *remaining -= totlen; | |
349 | ||
350 | return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); | |
351 | } | |
352 | ||
353 | /** | |
354 | * nlmsg_parse - parse attributes of a netlink message | |
355 | * @nlh: netlink message header | |
356 | * @hdrlen: length of family specific header | |
357 | * @tb: destination array with maxtype+1 elements | |
358 | * @maxtype: maximum attribute type to be expected | |
359 | * @policy: validation policy | |
360 | * | |
361 | * See nla_parse() | |
362 | */ | |
363 | static inline int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen, | |
364 | struct nlattr *tb[], int maxtype, | |
365 | struct nla_policy *policy) | |
366 | { | |
367 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | |
368 | return -EINVAL; | |
369 | ||
370 | return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), | |
371 | nlmsg_attrlen(nlh, hdrlen), policy); | |
372 | } | |
373 | ||
374 | /** | |
375 | * nlmsg_find_attr - find a specific attribute in a netlink message | |
376 | * @nlh: netlink message header | |
377 | * @hdrlen: length of familiy specific header | |
378 | * @attrtype: type of attribute to look for | |
379 | * | |
380 | * Returns the first attribute which matches the specified type. | |
381 | */ | |
382 | static inline struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh, | |
383 | int hdrlen, int attrtype) | |
384 | { | |
385 | return nla_find(nlmsg_attrdata(nlh, hdrlen), | |
386 | nlmsg_attrlen(nlh, hdrlen), attrtype); | |
387 | } | |
388 | ||
389 | /** | |
390 | * nlmsg_validate - validate a netlink message including attributes | |
391 | * @nlh: netlinket message header | |
392 | * @hdrlen: length of familiy specific header | |
393 | * @maxtype: maximum attribute type to be expected | |
394 | * @policy: validation policy | |
395 | */ | |
396 | static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype, | |
397 | struct nla_policy *policy) | |
398 | { | |
399 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | |
400 | return -EINVAL; | |
401 | ||
402 | return nla_validate(nlmsg_attrdata(nlh, hdrlen), | |
403 | nlmsg_attrlen(nlh, hdrlen), maxtype, policy); | |
404 | } | |
405 | ||
97676b6b TG |
406 | /** |
407 | * nlmsg_report - need to report back to application? | |
408 | * @nlh: netlink message header | |
409 | * | |
410 | * Returns 1 if a report back to the application is requested. | |
411 | */ | |
412 | static inline int nlmsg_report(struct nlmsghdr *nlh) | |
413 | { | |
414 | return !!(nlh->nlmsg_flags & NLM_F_ECHO); | |
415 | } | |
416 | ||
bfa83a9e TG |
417 | /** |
418 | * nlmsg_for_each_attr - iterate over a stream of attributes | |
419 | * @pos: loop counter, set to current attribute | |
420 | * @nlh: netlink message header | |
421 | * @hdrlen: length of familiy specific header | |
422 | * @rem: initialized to len, holds bytes currently remaining in stream | |
423 | */ | |
424 | #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ | |
425 | nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ | |
426 | nlmsg_attrlen(nlh, hdrlen), rem) | |
427 | ||
428 | #if 0 | |
429 | /* FIXME: Enable once all users have been converted */ | |
430 | ||
431 | /** | |
432 | * __nlmsg_put - Add a new netlink message to an skb | |
433 | * @skb: socket buffer to store message in | |
434 | * @pid: 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 | * The caller is responsible to ensure that the skb provides enough | |
441 | * tailroom for both the netlink header and payload. | |
442 | */ | |
443 | static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid, | |
444 | u32 seq, int type, int payload, | |
445 | int flags) | |
446 | { | |
447 | struct nlmsghdr *nlh; | |
448 | ||
449 | nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload)); | |
450 | nlh->nlmsg_type = type; | |
451 | nlh->nlmsg_len = nlmsg_msg_size(payload); | |
452 | nlh->nlmsg_flags = flags; | |
453 | nlh->nlmsg_pid = pid; | |
454 | nlh->nlmsg_seq = seq; | |
455 | ||
456 | memset((unsigned char *) nlmsg_data(nlh) + payload, 0, | |
457 | nlmsg_padlen(payload)); | |
458 | ||
459 | return nlh; | |
460 | } | |
461 | #endif | |
462 | ||
463 | /** | |
464 | * nlmsg_put - Add a new netlink message to an skb | |
465 | * @skb: socket buffer to store message in | |
466 | * @pid: netlink process id | |
467 | * @seq: sequence number of message | |
468 | * @type: message type | |
469 | * @payload: length of message payload | |
470 | * @flags: message flags | |
471 | * | |
472 | * Returns NULL if the tailroom of the skb is insufficient to store | |
473 | * the message header and payload. | |
474 | */ | |
475 | static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, | |
476 | int type, int payload, int flags) | |
477 | { | |
478 | if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) | |
479 | return NULL; | |
480 | ||
481 | return __nlmsg_put(skb, pid, seq, type, payload, flags); | |
482 | } | |
483 | ||
484 | /** | |
485 | * nlmsg_put_answer - Add a new callback based netlink message to an skb | |
486 | * @skb: socket buffer to store message in | |
487 | * @cb: netlink callback | |
488 | * @type: message type | |
489 | * @payload: length of message payload | |
490 | * @flags: message flags | |
491 | * | |
492 | * Returns NULL if the tailroom of the skb is insufficient to store | |
493 | * the message header and payload. | |
494 | */ | |
495 | static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, | |
496 | struct netlink_callback *cb, | |
497 | int type, int payload, | |
498 | int flags) | |
499 | { | |
500 | return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, | |
501 | type, payload, flags); | |
502 | } | |
503 | ||
504 | /** | |
505 | * nlmsg_new - Allocate a new netlink message | |
339bf98f | 506 | * @payload: size of the message payload |
fe4944e5 | 507 | * @flags: the type of memory to allocate. |
bfa83a9e | 508 | * |
339bf98f TG |
509 | * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known |
510 | * and a good default is needed. | |
bfa83a9e | 511 | */ |
339bf98f | 512 | static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) |
bfa83a9e | 513 | { |
339bf98f | 514 | return alloc_skb(nlmsg_total_size(payload), flags); |
bfa83a9e TG |
515 | } |
516 | ||
517 | /** | |
518 | * nlmsg_end - Finalize a netlink message | |
519 | * @skb: socket buffer the message is stored in | |
520 | * @nlh: netlink message header | |
521 | * | |
522 | * Corrects the netlink message header to include the appeneded | |
523 | * attributes. Only necessary if attributes have been added to | |
524 | * the message. | |
525 | * | |
526 | * Returns the total data length of the skb. | |
527 | */ | |
528 | static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) | |
529 | { | |
27a884dc | 530 | nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; |
bfa83a9e TG |
531 | |
532 | return skb->len; | |
533 | } | |
534 | ||
fe4944e5 TG |
535 | /** |
536 | * nlmsg_get_pos - return current position in netlink message | |
537 | * @skb: socket buffer the message is stored in | |
538 | * | |
539 | * Returns a pointer to the current tail of the message. | |
540 | */ | |
541 | static inline void *nlmsg_get_pos(struct sk_buff *skb) | |
542 | { | |
27a884dc | 543 | return skb_tail_pointer(skb); |
fe4944e5 TG |
544 | } |
545 | ||
546 | /** | |
547 | * nlmsg_trim - Trim message to a mark | |
548 | * @skb: socket buffer the message is stored in | |
549 | * @mark: mark to trim to | |
550 | * | |
551 | * Trims the message to the provided mark. Returns -1. | |
552 | */ | |
dc5fc579 | 553 | static inline int nlmsg_trim(struct sk_buff *skb, const void *mark) |
fe4944e5 TG |
554 | { |
555 | if (mark) | |
556 | skb_trim(skb, (unsigned char *) mark - skb->data); | |
557 | ||
558 | return -1; | |
559 | } | |
560 | ||
bfa83a9e TG |
561 | /** |
562 | * nlmsg_cancel - Cancel construction of a netlink message | |
563 | * @skb: socket buffer the message is stored in | |
564 | * @nlh: netlink message header | |
565 | * | |
566 | * Removes the complete netlink message including all | |
567 | * attributes from the socket buffer again. Returns -1. | |
568 | */ | |
569 | static inline int nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) | |
570 | { | |
fe4944e5 | 571 | return nlmsg_trim(skb, nlh); |
bfa83a9e TG |
572 | } |
573 | ||
574 | /** | |
575 | * nlmsg_free - free a netlink message | |
576 | * @skb: socket buffer of netlink message | |
577 | */ | |
578 | static inline void nlmsg_free(struct sk_buff *skb) | |
579 | { | |
580 | kfree_skb(skb); | |
581 | } | |
582 | ||
583 | /** | |
584 | * nlmsg_multicast - multicast a netlink message | |
585 | * @sk: netlink socket to spread messages to | |
586 | * @skb: netlink message as socket buffer | |
587 | * @pid: own netlink pid to avoid sending to yourself | |
588 | * @group: multicast group id | |
d387f6ad | 589 | * @flags: allocation flags |
bfa83a9e TG |
590 | */ |
591 | static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, | |
d387f6ad | 592 | u32 pid, unsigned int group, gfp_t flags) |
bfa83a9e TG |
593 | { |
594 | int err; | |
595 | ||
596 | NETLINK_CB(skb).dst_group = group; | |
597 | ||
d387f6ad | 598 | err = netlink_broadcast(sk, skb, pid, group, flags); |
bfa83a9e TG |
599 | if (err > 0) |
600 | err = 0; | |
601 | ||
602 | return err; | |
603 | } | |
604 | ||
605 | /** | |
606 | * nlmsg_unicast - unicast a netlink message | |
607 | * @sk: netlink socket to spread message to | |
608 | * @skb: netlink message as socket buffer | |
609 | * @pid: netlink pid of the destination socket | |
610 | */ | |
611 | static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid) | |
612 | { | |
613 | int err; | |
614 | ||
615 | err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT); | |
616 | if (err > 0) | |
617 | err = 0; | |
618 | ||
619 | return err; | |
620 | } | |
621 | ||
622 | /** | |
623 | * nlmsg_for_each_msg - iterate over a stream of messages | |
624 | * @pos: loop counter, set to current message | |
625 | * @head: head of message stream | |
626 | * @len: length of message stream | |
627 | * @rem: initialized to len, holds bytes currently remaining in stream | |
628 | */ | |
629 | #define nlmsg_for_each_msg(pos, head, len, rem) \ | |
630 | for (pos = head, rem = len; \ | |
631 | nlmsg_ok(pos, rem); \ | |
632 | pos = nlmsg_next(pos, &(rem))) | |
633 | ||
634 | /************************************************************************** | |
635 | * Netlink Attributes | |
636 | **************************************************************************/ | |
637 | ||
638 | /** | |
639 | * nla_attr_size - length of attribute not including padding | |
640 | * @payload: length of payload | |
641 | */ | |
642 | static inline int nla_attr_size(int payload) | |
643 | { | |
644 | return NLA_HDRLEN + payload; | |
645 | } | |
646 | ||
647 | /** | |
648 | * nla_total_size - total length of attribute including padding | |
649 | * @payload: length of payload | |
650 | */ | |
651 | static inline int nla_total_size(int payload) | |
652 | { | |
653 | return NLA_ALIGN(nla_attr_size(payload)); | |
654 | } | |
655 | ||
656 | /** | |
657 | * nla_padlen - length of padding at the tail of attribute | |
658 | * @payload: length of payload | |
659 | */ | |
660 | static inline int nla_padlen(int payload) | |
661 | { | |
662 | return nla_total_size(payload) - nla_attr_size(payload); | |
663 | } | |
664 | ||
665 | /** | |
666 | * nla_data - head of payload | |
667 | * @nla: netlink attribute | |
668 | */ | |
669 | static inline void *nla_data(const struct nlattr *nla) | |
670 | { | |
671 | return (char *) nla + NLA_HDRLEN; | |
672 | } | |
673 | ||
674 | /** | |
675 | * nla_len - length of payload | |
676 | * @nla: netlink attribute | |
677 | */ | |
678 | static inline int nla_len(const struct nlattr *nla) | |
679 | { | |
680 | return nla->nla_len - NLA_HDRLEN; | |
681 | } | |
682 | ||
683 | /** | |
684 | * nla_ok - check if the netlink attribute fits into the remaining bytes | |
685 | * @nla: netlink attribute | |
686 | * @remaining: number of bytes remaining in attribute stream | |
687 | */ | |
688 | static inline int nla_ok(const struct nlattr *nla, int remaining) | |
689 | { | |
690 | return remaining >= sizeof(*nla) && | |
691 | nla->nla_len >= sizeof(*nla) && | |
692 | nla->nla_len <= remaining; | |
693 | } | |
694 | ||
695 | /** | |
696 | * nla_next - next netlink attribte in attribute stream | |
697 | * @nla: netlink attribute | |
698 | * @remaining: number of bytes remaining in attribute stream | |
699 | * | |
700 | * Returns the next netlink attribute in the attribute stream and | |
701 | * decrements remaining by the size of the current attribute. | |
702 | */ | |
703 | static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) | |
704 | { | |
705 | int totlen = NLA_ALIGN(nla->nla_len); | |
706 | ||
707 | *remaining -= totlen; | |
708 | return (struct nlattr *) ((char *) nla + totlen); | |
709 | } | |
710 | ||
fe4944e5 TG |
711 | /** |
712 | * nla_find_nested - find attribute in a set of nested attributes | |
713 | * @nla: attribute containing the nested attributes | |
714 | * @attrtype: type of attribute to look for | |
715 | * | |
716 | * Returns the first attribute which matches the specified type. | |
717 | */ | |
718 | static inline struct nlattr *nla_find_nested(struct nlattr *nla, int attrtype) | |
719 | { | |
720 | return nla_find(nla_data(nla), nla_len(nla), attrtype); | |
721 | } | |
722 | ||
bfa83a9e TG |
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 | */ | |
732 | static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, | |
733 | struct nlattr *nla, | |
734 | struct nla_policy *policy) | |
735 | { | |
736 | return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); | |
737 | } | |
738 | /** | |
739 | * nla_put_u8 - Add a u16 netlink attribute to a socket buffer | |
740 | * @skb: socket buffer to add attribute to | |
741 | * @attrtype: attribute type | |
742 | * @value: numeric value | |
743 | */ | |
744 | static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) | |
745 | { | |
746 | return nla_put(skb, attrtype, sizeof(u8), &value); | |
747 | } | |
748 | ||
749 | /** | |
750 | * nla_put_u16 - Add a u16 netlink attribute to a socket buffer | |
751 | * @skb: socket buffer to add attribute to | |
752 | * @attrtype: attribute type | |
753 | * @value: numeric value | |
754 | */ | |
755 | static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) | |
756 | { | |
757 | return nla_put(skb, attrtype, sizeof(u16), &value); | |
758 | } | |
759 | ||
760 | /** | |
761 | * nla_put_u32 - Add a u32 netlink attribute to a socket buffer | |
762 | * @skb: socket buffer to add attribute to | |
763 | * @attrtype: attribute type | |
764 | * @value: numeric value | |
765 | */ | |
766 | static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) | |
767 | { | |
768 | return nla_put(skb, attrtype, sizeof(u32), &value); | |
769 | } | |
770 | ||
771 | /** | |
772 | * nla_put_64 - Add a u64 netlink attribute to a socket buffer | |
773 | * @skb: socket buffer to add attribute to | |
774 | * @attrtype: attribute type | |
775 | * @value: numeric value | |
776 | */ | |
777 | static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value) | |
778 | { | |
779 | return nla_put(skb, attrtype, sizeof(u64), &value); | |
780 | } | |
781 | ||
782 | /** | |
783 | * nla_put_string - Add a string netlink attribute to a socket buffer | |
784 | * @skb: socket buffer to add attribute to | |
785 | * @attrtype: attribute type | |
786 | * @str: NUL terminated string | |
787 | */ | |
788 | static inline int nla_put_string(struct sk_buff *skb, int attrtype, | |
789 | const char *str) | |
790 | { | |
791 | return nla_put(skb, attrtype, strlen(str) + 1, str); | |
792 | } | |
793 | ||
794 | /** | |
795 | * nla_put_flag - Add a flag netlink attribute to a socket buffer | |
796 | * @skb: socket buffer to add attribute to | |
797 | * @attrtype: attribute type | |
798 | */ | |
799 | static inline int nla_put_flag(struct sk_buff *skb, int attrtype) | |
800 | { | |
801 | return nla_put(skb, attrtype, 0, NULL); | |
802 | } | |
803 | ||
804 | /** | |
805 | * nla_put_msecs - Add a msecs netlink attribute to a socket buffer | |
806 | * @skb: socket buffer to add attribute to | |
807 | * @attrtype: attribute type | |
808 | * @jiffies: number of msecs in jiffies | |
809 | */ | |
810 | static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, | |
811 | unsigned long jiffies) | |
812 | { | |
813 | u64 tmp = jiffies_to_msecs(jiffies); | |
814 | return nla_put(skb, attrtype, sizeof(u64), &tmp); | |
815 | } | |
816 | ||
817 | #define NLA_PUT(skb, attrtype, attrlen, data) \ | |
818 | do { \ | |
819 | if (nla_put(skb, attrtype, attrlen, data) < 0) \ | |
820 | goto nla_put_failure; \ | |
821 | } while(0) | |
822 | ||
823 | #define NLA_PUT_TYPE(skb, type, attrtype, value) \ | |
824 | do { \ | |
825 | type __tmp = value; \ | |
826 | NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \ | |
827 | } while(0) | |
828 | ||
829 | #define NLA_PUT_U8(skb, attrtype, value) \ | |
830 | NLA_PUT_TYPE(skb, u8, attrtype, value) | |
831 | ||
832 | #define NLA_PUT_U16(skb, attrtype, value) \ | |
833 | NLA_PUT_TYPE(skb, u16, attrtype, value) | |
834 | ||
4a89c256 TG |
835 | #define NLA_PUT_LE16(skb, attrtype, value) \ |
836 | NLA_PUT_TYPE(skb, __le16, attrtype, value) | |
837 | ||
bfa83a9e TG |
838 | #define NLA_PUT_U32(skb, attrtype, value) \ |
839 | NLA_PUT_TYPE(skb, u32, attrtype, value) | |
840 | ||
00012e5b AV |
841 | #define NLA_PUT_BE32(skb, attrtype, value) \ |
842 | NLA_PUT_TYPE(skb, __be32, attrtype, value) | |
843 | ||
bfa83a9e TG |
844 | #define NLA_PUT_U64(skb, attrtype, value) \ |
845 | NLA_PUT_TYPE(skb, u64, attrtype, value) | |
846 | ||
847 | #define NLA_PUT_STRING(skb, attrtype, value) \ | |
848 | NLA_PUT(skb, attrtype, strlen(value) + 1, value) | |
849 | ||
ff5dfe73 | 850 | #define NLA_PUT_FLAG(skb, attrtype) \ |
bfa83a9e TG |
851 | NLA_PUT(skb, attrtype, 0, NULL) |
852 | ||
853 | #define NLA_PUT_MSECS(skb, attrtype, jiffies) \ | |
854 | NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies)) | |
855 | ||
856 | /** | |
857 | * nla_get_u32 - return payload of u32 attribute | |
858 | * @nla: u32 netlink attribute | |
859 | */ | |
860 | static inline u32 nla_get_u32(struct nlattr *nla) | |
861 | { | |
862 | return *(u32 *) nla_data(nla); | |
863 | } | |
864 | ||
00012e5b AV |
865 | /** |
866 | * nla_get_be32 - return payload of __be32 attribute | |
867 | * @nla: __be32 netlink attribute | |
868 | */ | |
869 | static inline __be32 nla_get_be32(struct nlattr *nla) | |
870 | { | |
871 | return *(__be32 *) nla_data(nla); | |
872 | } | |
873 | ||
bfa83a9e TG |
874 | /** |
875 | * nla_get_u16 - return payload of u16 attribute | |
876 | * @nla: u16 netlink attribute | |
877 | */ | |
878 | static inline u16 nla_get_u16(struct nlattr *nla) | |
879 | { | |
880 | return *(u16 *) nla_data(nla); | |
881 | } | |
882 | ||
4a89c256 TG |
883 | /** |
884 | * nla_get_le16 - return payload of __le16 attribute | |
885 | * @nla: __le16 netlink attribute | |
886 | */ | |
887 | static inline __le16 nla_get_le16(struct nlattr *nla) | |
888 | { | |
889 | return *(__le16 *) nla_data(nla); | |
890 | } | |
891 | ||
bfa83a9e TG |
892 | /** |
893 | * nla_get_u8 - return payload of u8 attribute | |
894 | * @nla: u8 netlink attribute | |
895 | */ | |
896 | static inline u8 nla_get_u8(struct nlattr *nla) | |
897 | { | |
898 | return *(u8 *) nla_data(nla); | |
899 | } | |
900 | ||
901 | /** | |
902 | * nla_get_u64 - return payload of u64 attribute | |
903 | * @nla: u64 netlink attribute | |
904 | */ | |
905 | static inline u64 nla_get_u64(struct nlattr *nla) | |
906 | { | |
907 | u64 tmp; | |
908 | ||
909 | nla_memcpy(&tmp, nla, sizeof(tmp)); | |
910 | ||
911 | return tmp; | |
912 | } | |
913 | ||
914 | /** | |
915 | * nla_get_flag - return payload of flag attribute | |
916 | * @nla: flag netlink attribute | |
917 | */ | |
918 | static inline int nla_get_flag(struct nlattr *nla) | |
919 | { | |
920 | return !!nla; | |
921 | } | |
922 | ||
923 | /** | |
924 | * nla_get_msecs - return payload of msecs attribute | |
925 | * @nla: msecs netlink attribute | |
926 | * | |
927 | * Returns the number of milliseconds in jiffies. | |
928 | */ | |
929 | static inline unsigned long nla_get_msecs(struct nlattr *nla) | |
930 | { | |
931 | u64 msecs = nla_get_u64(nla); | |
932 | ||
933 | return msecs_to_jiffies((unsigned long) msecs); | |
934 | } | |
935 | ||
936 | /** | |
937 | * nla_nest_start - Start a new level of nested attributes | |
938 | * @skb: socket buffer to add attributes to | |
939 | * @attrtype: attribute type of container | |
940 | * | |
941 | * Returns the container attribute | |
942 | */ | |
943 | static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) | |
944 | { | |
27a884dc | 945 | struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); |
bfa83a9e TG |
946 | |
947 | if (nla_put(skb, attrtype, 0, NULL) < 0) | |
948 | return NULL; | |
949 | ||
950 | return start; | |
951 | } | |
952 | ||
953 | /** | |
954 | * nla_nest_end - Finalize nesting of attributes | |
955 | * @skb: socket buffer the attribtues are stored in | |
956 | * @start: container attribute | |
957 | * | |
958 | * Corrects the container attribute header to include the all | |
959 | * appeneded attributes. | |
960 | * | |
961 | * Returns the total data length of the skb. | |
962 | */ | |
963 | static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) | |
964 | { | |
27a884dc | 965 | start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; |
bfa83a9e TG |
966 | return skb->len; |
967 | } | |
968 | ||
969 | /** | |
970 | * nla_nest_cancel - Cancel nesting of attributes | |
971 | * @skb: socket buffer the message is stored in | |
972 | * @start: container attribute | |
973 | * | |
974 | * Removes the container attribute and including all nested | |
975 | * attributes. Returns -1. | |
976 | */ | |
977 | static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) | |
978 | { | |
fe4944e5 | 979 | return nlmsg_trim(skb, start); |
bfa83a9e TG |
980 | } |
981 | ||
4fe5d5c0 PM |
982 | /** |
983 | * nla_validate_nested - Validate a stream of nested attributes | |
984 | * @start: container attribute | |
985 | * @maxtype: maximum attribute type to be expected | |
986 | * @policy: validation policy | |
987 | * | |
988 | * Validates all attributes in the nested attribute stream against the | |
989 | * specified policy. Attributes with a type exceeding maxtype will be | |
990 | * ignored. See documenation of struct nla_policy for more details. | |
991 | * | |
992 | * Returns 0 on success or a negative error code. | |
993 | */ | |
994 | static inline int nla_validate_nested(struct nlattr *start, int maxtype, | |
995 | struct nla_policy *policy) | |
996 | { | |
997 | return nla_validate(nla_data(start), nla_len(start), maxtype, policy); | |
998 | } | |
999 | ||
bfa83a9e TG |
1000 | /** |
1001 | * nla_for_each_attr - iterate over a stream of attributes | |
1002 | * @pos: loop counter, set to current attribute | |
1003 | * @head: head of attribute stream | |
1004 | * @len: length of attribute stream | |
1005 | * @rem: initialized to len, holds bytes currently remaining in stream | |
1006 | */ | |
1007 | #define nla_for_each_attr(pos, head, len, rem) \ | |
1008 | for (pos = head, rem = len; \ | |
1009 | nla_ok(pos, rem); \ | |
1010 | pos = nla_next(pos, &(rem))) | |
1011 | ||
fe4944e5 TG |
1012 | /** |
1013 | * nla_for_each_nested - iterate over nested attributes | |
1014 | * @pos: loop counter, set to current attribute | |
1015 | * @nla: attribute containing the nested attributes | |
1016 | * @rem: initialized to len, holds bytes currently remaining in stream | |
1017 | */ | |
1018 | #define nla_for_each_nested(pos, nla, rem) \ | |
1019 | nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) | |
1020 | ||
bfa83a9e | 1021 | #endif |