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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>
Al Virod7fe0f22006-12-03 23:15:30 -05006#include <linux/jiffies.h>
Thomas Grafbfa83a92005-11-10 02:25:51 +01007
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
Thomas Graffe4944e2006-08-04 23:03:05 -070039 * nlmsg_get_pos() return current position in message
40 * nlmsg_trim() trim part of message
Thomas Grafbfa83a92005-11-10 02:25:51 +010041 * 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
Thomas Grafd387f6a2006-08-15 00:31:06 -070047 * nlmsg_notify() send notification message
Thomas Grafbfa83a92005-11-10 02:25:51 +010048 *
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 *
Thomas Graf97676b62006-08-15 00:31:41 -070069 * Misc:
70 * nlmsg_report() report back to application?
71 *
Thomas Grafbfa83a92005-11-10 02:25:51 +010072 * ------------------------------------------------------------------------
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:
Pierre Ynardd1ec3b72007-10-10 21:09:48 -070087 * struct nlattr netlink attribute header
Thomas Grafbfa83a92005-11-10 02:25:51 +010088 *
89 * Attribute Construction:
Thomas Graffe4944e2006-08-04 23:03:05 -070090 * nla_reserve(skb, type, len) reserve room for an attribute
91 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
Thomas Grafbfa83a92005-11-10 02:25:51 +010092 * nla_put(skb, type, len, data) add attribute to skb
Thomas Graffe4944e2006-08-04 23:03:05 -070093 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
Thomas Grafbfa83a92005-11-10 02:25:51 +010094 *
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
Patrick McHardy1092cb22007-06-25 13:49:35 -0700121 * nla_nest_compat_start(skb, type, start a nested compat attribute
122 * len, data)
123 * nla_nest_compat_end(skb, type) finalize a nested compat attribute
Thomas Grafbfa83a92005-11-10 02:25:51 +0100124 * nla_nest_cancel(skb, nla) cancel nested attribute construction
125 *
126 * Attribute Length Calculations:
127 * nla_attr_size(payload) length of attribute w/o padding
128 * nla_total_size(payload) length of attribute w/ padding
129 * nla_padlen(payload) length of padding
130 *
131 * Attribute Payload Access:
132 * nla_data(nla) head of attribute payload
133 * nla_len(nla) length of attribute payload
134 *
135 * Attribute Payload Access for Basic Types:
136 * nla_get_u8(nla) get payload for a u8 attribute
137 * nla_get_u16(nla) get payload for a u16 attribute
138 * nla_get_u32(nla) get payload for a u32 attribute
139 * nla_get_u64(nla) get payload for a u64 attribute
140 * nla_get_flag(nla) return 1 if flag is true
141 * nla_get_msecs(nla) get payload for a msecs attribute
142 *
143 * Attribute Misc:
144 * nla_memcpy(dest, nla, count) copy attribute into memory
145 * nla_memcmp(nla, data, size) compare attribute with memory area
146 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
147 * nla_strcmp(nla, str) compare attribute with string
148 *
149 * Attribute Parsing:
150 * nla_ok(nla, remaining) does nla fit into remaining bytes?
151 * nla_next(nla, remaining) get next netlink attribute
152 * nla_validate() validate a stream of attributes
Paul Moore4fe5d5c2006-09-25 15:54:03 -0700153 * nla_validate_nested() validate a stream of nested attributes
Thomas Grafbfa83a92005-11-10 02:25:51 +0100154 * nla_find() find attribute in stream of attributes
Thomas Graffe4944e2006-08-04 23:03:05 -0700155 * nla_find_nested() find attribute in nested attributes
Thomas Grafbfa83a92005-11-10 02:25:51 +0100156 * nla_parse() parse and validate stream of attrs
157 * nla_parse_nested() parse nested attribuets
Patrick McHardy1092cb22007-06-25 13:49:35 -0700158 * nla_parse_nested_compat() parse nested compat attributes
Thomas Grafbfa83a92005-11-10 02:25:51 +0100159 * nla_for_each_attr() loop over all attributes
Paul Moore22acb192006-09-25 15:53:37 -0700160 * nla_for_each_nested() loop over the nested attributes
Thomas Grafbfa83a92005-11-10 02:25:51 +0100161 *=========================================================================
162 */
163
164 /**
165 * Standard attribute types to specify validation policy
166 */
167enum {
168 NLA_UNSPEC,
169 NLA_U8,
170 NLA_U16,
171 NLA_U32,
172 NLA_U64,
173 NLA_STRING,
174 NLA_FLAG,
175 NLA_MSECS,
176 NLA_NESTED,
Patrick McHardy1092cb22007-06-25 13:49:35 -0700177 NLA_NESTED_COMPAT,
Thomas Grafa5531a52006-08-26 20:11:47 -0700178 NLA_NUL_STRING,
Johannes Bergd30045a2007-03-23 11:37:48 -0700179 NLA_BINARY,
Thomas Grafbfa83a92005-11-10 02:25:51 +0100180 __NLA_TYPE_MAX,
181};
182
183#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
184
185/**
186 * struct nla_policy - attribute validation policy
187 * @type: Type of attribute or NLA_UNSPEC
Thomas Grafa5531a52006-08-26 20:11:47 -0700188 * @len: Type specific length of payload
Thomas Grafbfa83a92005-11-10 02:25:51 +0100189 *
190 * Policies are defined as arrays of this struct, the array must be
191 * accessible by attribute type up to the highest identifier to be expected.
192 *
Thomas Grafa5531a52006-08-26 20:11:47 -0700193 * Meaning of `len' field:
194 * NLA_STRING Maximum length of string
195 * NLA_NUL_STRING Maximum length of string (excluding NUL)
196 * NLA_FLAG Unused
Johannes Bergd30045a2007-03-23 11:37:48 -0700197 * NLA_BINARY Maximum length of attribute payload
Patrick McHardy1092cb22007-06-25 13:49:35 -0700198 * NLA_NESTED_COMPAT Exact length of structure payload
Thomas Grafa5531a52006-08-26 20:11:47 -0700199 * All other Exact length of attribute payload
200 *
Thomas Grafbfa83a92005-11-10 02:25:51 +0100201 * Example:
202 * static struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = {
203 * [ATTR_FOO] = { .type = NLA_U16 },
Johannes Bergd30045a2007-03-23 11:37:48 -0700204 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
Thomas Grafa5531a52006-08-26 20:11:47 -0700205 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
Thomas Grafbfa83a92005-11-10 02:25:51 +0100206 * };
207 */
208struct nla_policy {
209 u16 type;
Thomas Grafa5531a52006-08-26 20:11:47 -0700210 u16 len;
Thomas Grafbfa83a92005-11-10 02:25:51 +0100211};
212
Thomas Graf4e902c52006-08-17 18:14:52 -0700213/**
214 * struct nl_info - netlink source information
215 * @nlh: Netlink message header of original request
216 * @pid: Netlink PID of requesting application
217 */
218struct nl_info {
219 struct nlmsghdr *nlh;
220 u32 pid;
221};
222
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700223extern int netlink_rcv_skb(struct sk_buff *skb,
224 int (*cb)(struct sk_buff *,
225 struct nlmsghdr *));
Thomas Graf97676b62006-08-15 00:31:41 -0700226extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb,
227 u32 pid, unsigned int group, int report,
228 gfp_t flags);
Thomas Graf82ace472005-11-10 02:25:53 +0100229
Thomas Grafbfa83a92005-11-10 02:25:51 +0100230extern int nla_validate(struct nlattr *head, int len, int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700231 const struct nla_policy *policy);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100232extern int nla_parse(struct nlattr *tb[], int maxtype,
233 struct nlattr *head, int len,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700234 const struct nla_policy *policy);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100235extern struct nlattr * nla_find(struct nlattr *head, int len, int attrtype);
236extern size_t nla_strlcpy(char *dst, const struct nlattr *nla,
237 size_t dstsize);
238extern int nla_memcpy(void *dest, struct nlattr *src, int count);
239extern int nla_memcmp(const struct nlattr *nla, const void *data,
240 size_t size);
241extern int nla_strcmp(const struct nlattr *nla, const char *str);
242extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype,
243 int attrlen);
Thomas Graffe4944e2006-08-04 23:03:05 -0700244extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100245extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype,
246 int attrlen);
Thomas Graffe4944e2006-08-04 23:03:05 -0700247extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100248extern void __nla_put(struct sk_buff *skb, int attrtype,
249 int attrlen, const void *data);
Thomas Graffe4944e2006-08-04 23:03:05 -0700250extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen,
251 const void *data);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100252extern int nla_put(struct sk_buff *skb, int attrtype,
253 int attrlen, const void *data);
Thomas Graffe4944e2006-08-04 23:03:05 -0700254extern int nla_put_nohdr(struct sk_buff *skb, int attrlen,
255 const void *data);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100256
257/**************************************************************************
258 * Netlink Messages
259 **************************************************************************/
260
261/**
262 * nlmsg_msg_size - length of netlink message not including padding
263 * @payload: length of message payload
264 */
265static inline int nlmsg_msg_size(int payload)
266{
267 return NLMSG_HDRLEN + payload;
268}
269
270/**
271 * nlmsg_total_size - length of netlink message including padding
272 * @payload: length of message payload
273 */
274static inline int nlmsg_total_size(int payload)
275{
276 return NLMSG_ALIGN(nlmsg_msg_size(payload));
277}
278
279/**
280 * nlmsg_padlen - length of padding at the message's tail
281 * @payload: length of message payload
282 */
283static inline int nlmsg_padlen(int payload)
284{
285 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
286}
287
288/**
289 * nlmsg_data - head of message payload
290 * @nlh: netlink messsage header
291 */
292static inline void *nlmsg_data(const struct nlmsghdr *nlh)
293{
294 return (unsigned char *) nlh + NLMSG_HDRLEN;
295}
296
297/**
298 * nlmsg_len - length of message payload
299 * @nlh: netlink message header
300 */
301static inline int nlmsg_len(const struct nlmsghdr *nlh)
302{
303 return nlh->nlmsg_len - NLMSG_HDRLEN;
304}
305
306/**
307 * nlmsg_attrdata - head of attributes data
308 * @nlh: netlink message header
309 * @hdrlen: length of family specific header
310 */
311static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
312 int hdrlen)
313{
314 unsigned char *data = nlmsg_data(nlh);
315 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
316}
317
318/**
319 * nlmsg_attrlen - length of attributes data
320 * @nlh: netlink message header
321 * @hdrlen: length of family specific header
322 */
323static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
324{
325 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
326}
327
328/**
329 * nlmsg_ok - check if the netlink message fits into the remaining bytes
330 * @nlh: netlink message header
331 * @remaining: number of bytes remaining in message stream
332 */
333static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
334{
335 return (remaining >= sizeof(struct nlmsghdr) &&
336 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
337 nlh->nlmsg_len <= remaining);
338}
339
340/**
341 * nlmsg_next - next netlink message in message stream
342 * @nlh: netlink message header
343 * @remaining: number of bytes remaining in message stream
344 *
345 * Returns the next netlink message in the message stream and
346 * decrements remaining by the size of the current message.
347 */
348static inline struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining)
349{
350 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
351
352 *remaining -= totlen;
353
354 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
355}
356
357/**
358 * nlmsg_parse - parse attributes of a netlink message
359 * @nlh: netlink message header
360 * @hdrlen: length of family specific header
361 * @tb: destination array with maxtype+1 elements
362 * @maxtype: maximum attribute type to be expected
363 * @policy: validation policy
364 *
365 * See nla_parse()
366 */
367static inline int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen,
368 struct nlattr *tb[], int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700369 const struct nla_policy *policy)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100370{
371 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
372 return -EINVAL;
373
374 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
375 nlmsg_attrlen(nlh, hdrlen), policy);
376}
377
378/**
379 * nlmsg_find_attr - find a specific attribute in a netlink message
380 * @nlh: netlink message header
381 * @hdrlen: length of familiy specific header
382 * @attrtype: type of attribute to look for
383 *
384 * Returns the first attribute which matches the specified type.
385 */
386static inline struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh,
387 int hdrlen, int attrtype)
388{
389 return nla_find(nlmsg_attrdata(nlh, hdrlen),
390 nlmsg_attrlen(nlh, hdrlen), attrtype);
391}
392
393/**
394 * nlmsg_validate - validate a netlink message including attributes
395 * @nlh: netlinket message header
396 * @hdrlen: length of familiy specific header
397 * @maxtype: maximum attribute type to be expected
398 * @policy: validation policy
399 */
400static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700401 const struct nla_policy *policy)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100402{
403 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
404 return -EINVAL;
405
406 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
407 nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
408}
409
410/**
Thomas Graf97676b62006-08-15 00:31:41 -0700411 * nlmsg_report - need to report back to application?
412 * @nlh: netlink message header
413 *
414 * Returns 1 if a report back to the application is requested.
415 */
416static inline int nlmsg_report(struct nlmsghdr *nlh)
417{
418 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
419}
420
421/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100422 * nlmsg_for_each_attr - iterate over a stream of attributes
423 * @pos: loop counter, set to current attribute
424 * @nlh: netlink message header
425 * @hdrlen: length of familiy specific header
426 * @rem: initialized to len, holds bytes currently remaining in stream
427 */
428#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
429 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
430 nlmsg_attrlen(nlh, hdrlen), rem)
431
432#if 0
433/* FIXME: Enable once all users have been converted */
434
435/**
436 * __nlmsg_put - Add a new netlink message to an skb
437 * @skb: socket buffer to store message in
438 * @pid: netlink process id
439 * @seq: sequence number of message
440 * @type: message type
441 * @payload: length of message payload
442 * @flags: message flags
443 *
444 * The caller is responsible to ensure that the skb provides enough
445 * tailroom for both the netlink header and payload.
446 */
447static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid,
448 u32 seq, int type, int payload,
449 int flags)
450{
451 struct nlmsghdr *nlh;
452
453 nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload));
454 nlh->nlmsg_type = type;
455 nlh->nlmsg_len = nlmsg_msg_size(payload);
456 nlh->nlmsg_flags = flags;
457 nlh->nlmsg_pid = pid;
458 nlh->nlmsg_seq = seq;
459
460 memset((unsigned char *) nlmsg_data(nlh) + payload, 0,
461 nlmsg_padlen(payload));
462
463 return nlh;
464}
465#endif
466
467/**
468 * nlmsg_put - Add a new netlink message to an skb
469 * @skb: socket buffer to store message in
470 * @pid: netlink process id
471 * @seq: sequence number of message
472 * @type: message type
473 * @payload: length of message payload
474 * @flags: message flags
475 *
476 * Returns NULL if the tailroom of the skb is insufficient to store
477 * the message header and payload.
478 */
479static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
480 int type, int payload, int flags)
481{
482 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
483 return NULL;
484
485 return __nlmsg_put(skb, pid, seq, type, payload, flags);
486}
487
488/**
489 * nlmsg_put_answer - Add a new callback based netlink message to an skb
490 * @skb: socket buffer to store message in
491 * @cb: netlink callback
492 * @type: message type
493 * @payload: length of message payload
494 * @flags: message flags
495 *
496 * Returns NULL if the tailroom of the skb is insufficient to store
497 * the message header and payload.
498 */
499static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
500 struct netlink_callback *cb,
501 int type, int payload,
502 int flags)
503{
504 return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
505 type, payload, flags);
506}
507
508/**
509 * nlmsg_new - Allocate a new netlink message
Thomas Graf339bf982006-11-10 14:10:15 -0800510 * @payload: size of the message payload
Thomas Graffe4944e2006-08-04 23:03:05 -0700511 * @flags: the type of memory to allocate.
Thomas Grafbfa83a92005-11-10 02:25:51 +0100512 *
Thomas Graf339bf982006-11-10 14:10:15 -0800513 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
514 * and a good default is needed.
Thomas Grafbfa83a92005-11-10 02:25:51 +0100515 */
Thomas Graf339bf982006-11-10 14:10:15 -0800516static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100517{
Thomas Graf339bf982006-11-10 14:10:15 -0800518 return alloc_skb(nlmsg_total_size(payload), flags);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100519}
520
521/**
522 * nlmsg_end - Finalize a netlink message
523 * @skb: socket buffer the message is stored in
524 * @nlh: netlink message header
525 *
526 * Corrects the netlink message header to include the appeneded
527 * attributes. Only necessary if attributes have been added to
528 * the message.
529 *
530 * Returns the total data length of the skb.
531 */
532static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
533{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700534 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
Thomas Grafbfa83a92005-11-10 02:25:51 +0100535
536 return skb->len;
537}
538
539/**
Thomas Graffe4944e2006-08-04 23:03:05 -0700540 * nlmsg_get_pos - return current position in netlink message
541 * @skb: socket buffer the message is stored in
542 *
543 * Returns a pointer to the current tail of the message.
544 */
545static inline void *nlmsg_get_pos(struct sk_buff *skb)
546{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700547 return skb_tail_pointer(skb);
Thomas Graffe4944e2006-08-04 23:03:05 -0700548}
549
550/**
551 * nlmsg_trim - Trim message to a mark
552 * @skb: socket buffer the message is stored in
553 * @mark: mark to trim to
554 *
555 * Trims the message to the provided mark. Returns -1.
556 */
Arnaldo Carvalho de Melodc5fc572007-03-25 23:06:12 -0700557static inline int nlmsg_trim(struct sk_buff *skb, const void *mark)
Thomas Graffe4944e2006-08-04 23:03:05 -0700558{
559 if (mark)
560 skb_trim(skb, (unsigned char *) mark - skb->data);
561
562 return -1;
563}
564
565/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100566 * nlmsg_cancel - Cancel construction of a netlink message
567 * @skb: socket buffer the message is stored in
568 * @nlh: netlink message header
569 *
570 * Removes the complete netlink message including all
571 * attributes from the socket buffer again. Returns -1.
572 */
573static inline int nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
574{
Thomas Graffe4944e2006-08-04 23:03:05 -0700575 return nlmsg_trim(skb, nlh);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100576}
577
578/**
579 * nlmsg_free - free a netlink message
580 * @skb: socket buffer of netlink message
581 */
582static inline void nlmsg_free(struct sk_buff *skb)
583{
584 kfree_skb(skb);
585}
586
587/**
588 * nlmsg_multicast - multicast a netlink message
589 * @sk: netlink socket to spread messages to
590 * @skb: netlink message as socket buffer
591 * @pid: own netlink pid to avoid sending to yourself
592 * @group: multicast group id
Thomas Grafd387f6a2006-08-15 00:31:06 -0700593 * @flags: allocation flags
Thomas Grafbfa83a92005-11-10 02:25:51 +0100594 */
595static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
Thomas Grafd387f6a2006-08-15 00:31:06 -0700596 u32 pid, unsigned int group, gfp_t flags)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100597{
598 int err;
599
600 NETLINK_CB(skb).dst_group = group;
601
Thomas Grafd387f6a2006-08-15 00:31:06 -0700602 err = netlink_broadcast(sk, skb, pid, group, flags);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100603 if (err > 0)
604 err = 0;
605
606 return err;
607}
608
609/**
610 * nlmsg_unicast - unicast a netlink message
611 * @sk: netlink socket to spread message to
612 * @skb: netlink message as socket buffer
613 * @pid: netlink pid of the destination socket
614 */
615static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid)
616{
617 int err;
618
619 err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT);
620 if (err > 0)
621 err = 0;
622
623 return err;
624}
625
626/**
627 * nlmsg_for_each_msg - iterate over a stream of messages
628 * @pos: loop counter, set to current message
629 * @head: head of message stream
630 * @len: length of message stream
631 * @rem: initialized to len, holds bytes currently remaining in stream
632 */
633#define nlmsg_for_each_msg(pos, head, len, rem) \
634 for (pos = head, rem = len; \
635 nlmsg_ok(pos, rem); \
636 pos = nlmsg_next(pos, &(rem)))
637
638/**************************************************************************
639 * Netlink Attributes
640 **************************************************************************/
641
642/**
643 * nla_attr_size - length of attribute not including padding
644 * @payload: length of payload
645 */
646static inline int nla_attr_size(int payload)
647{
648 return NLA_HDRLEN + payload;
649}
650
651/**
652 * nla_total_size - total length of attribute including padding
653 * @payload: length of payload
654 */
655static inline int nla_total_size(int payload)
656{
657 return NLA_ALIGN(nla_attr_size(payload));
658}
659
660/**
661 * nla_padlen - length of padding at the tail of attribute
662 * @payload: length of payload
663 */
664static inline int nla_padlen(int payload)
665{
666 return nla_total_size(payload) - nla_attr_size(payload);
667}
668
669/**
Thomas Graf8f4c1f92007-09-12 14:44:36 +0200670 * nla_type - attribute type
671 * @nla: netlink attribute
672 */
673static inline int nla_type(const struct nlattr *nla)
674{
675 return nla->nla_type & NLA_TYPE_MASK;
676}
677
678/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100679 * nla_data - head of payload
680 * @nla: netlink attribute
681 */
682static inline void *nla_data(const struct nlattr *nla)
683{
684 return (char *) nla + NLA_HDRLEN;
685}
686
687/**
688 * nla_len - length of payload
689 * @nla: netlink attribute
690 */
691static inline int nla_len(const struct nlattr *nla)
692{
693 return nla->nla_len - NLA_HDRLEN;
694}
695
696/**
697 * nla_ok - check if the netlink attribute fits into the remaining bytes
698 * @nla: netlink attribute
699 * @remaining: number of bytes remaining in attribute stream
700 */
701static inline int nla_ok(const struct nlattr *nla, int remaining)
702{
703 return remaining >= sizeof(*nla) &&
704 nla->nla_len >= sizeof(*nla) &&
705 nla->nla_len <= remaining;
706}
707
708/**
Pierre Ynardd1ec3b72007-10-10 21:09:48 -0700709 * nla_next - next netlink attribute in attribute stream
Thomas Grafbfa83a92005-11-10 02:25:51 +0100710 * @nla: netlink attribute
711 * @remaining: number of bytes remaining in attribute stream
712 *
713 * Returns the next netlink attribute in the attribute stream and
714 * decrements remaining by the size of the current attribute.
715 */
716static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
717{
718 int totlen = NLA_ALIGN(nla->nla_len);
719
720 *remaining -= totlen;
721 return (struct nlattr *) ((char *) nla + totlen);
722}
723
724/**
Thomas Graffe4944e2006-08-04 23:03:05 -0700725 * nla_find_nested - find attribute in a set of nested attributes
726 * @nla: attribute containing the nested attributes
727 * @attrtype: type of attribute to look for
728 *
729 * Returns the first attribute which matches the specified type.
730 */
731static inline struct nlattr *nla_find_nested(struct nlattr *nla, int attrtype)
732{
733 return nla_find(nla_data(nla), nla_len(nla), attrtype);
734}
735
736/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100737 * nla_parse_nested - parse nested attributes
738 * @tb: destination array with maxtype+1 elements
739 * @maxtype: maximum attribute type to be expected
740 * @nla: attribute containing the nested attributes
741 * @policy: validation policy
742 *
743 * See nla_parse()
744 */
745static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
746 struct nlattr *nla,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700747 const struct nla_policy *policy)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100748{
749 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
750}
Patrick McHardy1092cb22007-06-25 13:49:35 -0700751
752/**
753 * nla_parse_nested_compat - parse nested compat attributes
754 * @tb: destination array with maxtype+1 elements
755 * @maxtype: maximum attribute type to be expected
756 * @nla: attribute containing the nested attributes
757 * @data: pointer to point to contained structure
758 * @len: length of contained structure
759 * @policy: validation policy
760 *
761 * Parse a nested compat attribute. The compat attribute contains a structure
762 * and optionally a set of nested attributes. On success the data pointer
763 * points to the nested data and tb contains the parsed attributes
764 * (see nla_parse).
765 */
766static inline int __nla_parse_nested_compat(struct nlattr *tb[], int maxtype,
767 struct nlattr *nla,
768 const struct nla_policy *policy,
769 int len)
770{
771 if (nla_len(nla) < len)
772 return -1;
773 if (nla_len(nla) >= NLA_ALIGN(len) + sizeof(struct nlattr))
774 return nla_parse_nested(tb, maxtype,
775 nla_data(nla) + NLA_ALIGN(len),
776 policy);
777 memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
778 return 0;
779}
780
781#define nla_parse_nested_compat(tb, maxtype, nla, policy, data, len) \
782({ data = nla_len(nla) >= len ? nla_data(nla) : NULL; \
783 __nla_parse_nested_compat(tb, maxtype, nla, policy, len); })
Thomas Grafbfa83a92005-11-10 02:25:51 +0100784/**
Pierre Ynardd1ec3b72007-10-10 21:09:48 -0700785 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
Thomas Grafbfa83a92005-11-10 02:25:51 +0100786 * @skb: socket buffer to add attribute to
787 * @attrtype: attribute type
788 * @value: numeric value
789 */
790static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
791{
792 return nla_put(skb, attrtype, sizeof(u8), &value);
793}
794
795/**
796 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
797 * @skb: socket buffer to add attribute to
798 * @attrtype: attribute type
799 * @value: numeric value
800 */
801static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
802{
803 return nla_put(skb, attrtype, sizeof(u16), &value);
804}
805
806/**
807 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
808 * @skb: socket buffer to add attribute to
809 * @attrtype: attribute type
810 * @value: numeric value
811 */
812static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
813{
814 return nla_put(skb, attrtype, sizeof(u32), &value);
815}
816
817/**
818 * nla_put_64 - Add a u64 netlink attribute to a socket buffer
819 * @skb: socket buffer to add attribute to
820 * @attrtype: attribute type
821 * @value: numeric value
822 */
823static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
824{
825 return nla_put(skb, attrtype, sizeof(u64), &value);
826}
827
828/**
829 * nla_put_string - Add a string netlink attribute to a socket buffer
830 * @skb: socket buffer to add attribute to
831 * @attrtype: attribute type
832 * @str: NUL terminated string
833 */
834static inline int nla_put_string(struct sk_buff *skb, int attrtype,
835 const char *str)
836{
837 return nla_put(skb, attrtype, strlen(str) + 1, str);
838}
839
840/**
841 * nla_put_flag - Add a flag netlink attribute to a socket buffer
842 * @skb: socket buffer to add attribute to
843 * @attrtype: attribute type
844 */
845static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
846{
847 return nla_put(skb, attrtype, 0, NULL);
848}
849
850/**
851 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer
852 * @skb: socket buffer to add attribute to
853 * @attrtype: attribute type
854 * @jiffies: number of msecs in jiffies
855 */
856static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
857 unsigned long jiffies)
858{
859 u64 tmp = jiffies_to_msecs(jiffies);
860 return nla_put(skb, attrtype, sizeof(u64), &tmp);
861}
862
863#define NLA_PUT(skb, attrtype, attrlen, data) \
864 do { \
865 if (nla_put(skb, attrtype, attrlen, data) < 0) \
866 goto nla_put_failure; \
867 } while(0)
868
869#define NLA_PUT_TYPE(skb, type, attrtype, value) \
870 do { \
871 type __tmp = value; \
872 NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \
873 } while(0)
874
875#define NLA_PUT_U8(skb, attrtype, value) \
876 NLA_PUT_TYPE(skb, u8, attrtype, value)
877
878#define NLA_PUT_U16(skb, attrtype, value) \
879 NLA_PUT_TYPE(skb, u16, attrtype, value)
880
Thomas Graf4a89c252006-11-24 17:14:51 -0800881#define NLA_PUT_LE16(skb, attrtype, value) \
882 NLA_PUT_TYPE(skb, __le16, attrtype, value)
883
Thomas Grafbfa83a92005-11-10 02:25:51 +0100884#define NLA_PUT_U32(skb, attrtype, value) \
885 NLA_PUT_TYPE(skb, u32, attrtype, value)
886
Al Viro00012e52006-09-26 22:14:41 -0700887#define NLA_PUT_BE32(skb, attrtype, value) \
888 NLA_PUT_TYPE(skb, __be32, attrtype, value)
889
Thomas Grafbfa83a92005-11-10 02:25:51 +0100890#define NLA_PUT_U64(skb, attrtype, value) \
891 NLA_PUT_TYPE(skb, u64, attrtype, value)
892
893#define NLA_PUT_STRING(skb, attrtype, value) \
894 NLA_PUT(skb, attrtype, strlen(value) + 1, value)
895
Johannes Bergff5dfe72006-08-26 19:17:53 -0700896#define NLA_PUT_FLAG(skb, attrtype) \
Thomas Grafbfa83a92005-11-10 02:25:51 +0100897 NLA_PUT(skb, attrtype, 0, NULL)
898
899#define NLA_PUT_MSECS(skb, attrtype, jiffies) \
900 NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies))
901
902/**
903 * nla_get_u32 - return payload of u32 attribute
904 * @nla: u32 netlink attribute
905 */
906static inline u32 nla_get_u32(struct nlattr *nla)
907{
908 return *(u32 *) nla_data(nla);
909}
910
911/**
Al Viro00012e52006-09-26 22:14:41 -0700912 * nla_get_be32 - return payload of __be32 attribute
913 * @nla: __be32 netlink attribute
914 */
915static inline __be32 nla_get_be32(struct nlattr *nla)
916{
917 return *(__be32 *) nla_data(nla);
918}
919
920/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100921 * nla_get_u16 - return payload of u16 attribute
922 * @nla: u16 netlink attribute
923 */
924static inline u16 nla_get_u16(struct nlattr *nla)
925{
926 return *(u16 *) nla_data(nla);
927}
928
929/**
Thomas Graf4a89c252006-11-24 17:14:51 -0800930 * nla_get_le16 - return payload of __le16 attribute
931 * @nla: __le16 netlink attribute
932 */
933static inline __le16 nla_get_le16(struct nlattr *nla)
934{
935 return *(__le16 *) nla_data(nla);
936}
937
938/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100939 * nla_get_u8 - return payload of u8 attribute
940 * @nla: u8 netlink attribute
941 */
942static inline u8 nla_get_u8(struct nlattr *nla)
943{
944 return *(u8 *) nla_data(nla);
945}
946
947/**
948 * nla_get_u64 - return payload of u64 attribute
949 * @nla: u64 netlink attribute
950 */
951static inline u64 nla_get_u64(struct nlattr *nla)
952{
953 u64 tmp;
954
955 nla_memcpy(&tmp, nla, sizeof(tmp));
956
957 return tmp;
958}
959
960/**
961 * nla_get_flag - return payload of flag attribute
962 * @nla: flag netlink attribute
963 */
964static inline int nla_get_flag(struct nlattr *nla)
965{
966 return !!nla;
967}
968
969/**
970 * nla_get_msecs - return payload of msecs attribute
971 * @nla: msecs netlink attribute
972 *
973 * Returns the number of milliseconds in jiffies.
974 */
975static inline unsigned long nla_get_msecs(struct nlattr *nla)
976{
977 u64 msecs = nla_get_u64(nla);
978
979 return msecs_to_jiffies((unsigned long) msecs);
980}
981
982/**
983 * nla_nest_start - Start a new level of nested attributes
984 * @skb: socket buffer to add attributes to
985 * @attrtype: attribute type of container
986 *
987 * Returns the container attribute
988 */
989static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
990{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700991 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100992
993 if (nla_put(skb, attrtype, 0, NULL) < 0)
994 return NULL;
995
996 return start;
997}
998
999/**
1000 * nla_nest_end - Finalize nesting of attributes
Pierre Ynardd1ec3b72007-10-10 21:09:48 -07001001 * @skb: socket buffer the attributes are stored in
Thomas Grafbfa83a92005-11-10 02:25:51 +01001002 * @start: container attribute
1003 *
1004 * Corrects the container attribute header to include the all
1005 * appeneded attributes.
1006 *
1007 * Returns the total data length of the skb.
1008 */
1009static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1010{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001011 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
Thomas Grafbfa83a92005-11-10 02:25:51 +01001012 return skb->len;
1013}
1014
1015/**
Patrick McHardy1092cb22007-06-25 13:49:35 -07001016 * nla_nest_compat_start - Start a new level of nested compat attributes
1017 * @skb: socket buffer to add attributes to
1018 * @attrtype: attribute type of container
1019 * @attrlen: length of structure
1020 * @data: pointer to structure
1021 *
1022 * Start a nested compat attribute that contains both a structure and
1023 * a set of nested attributes.
1024 *
1025 * Returns the container attribute
1026 */
1027static inline struct nlattr *nla_nest_compat_start(struct sk_buff *skb,
1028 int attrtype, int attrlen,
1029 const void *data)
1030{
1031 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1032
1033 if (nla_put(skb, attrtype, attrlen, data) < 0)
1034 return NULL;
1035 if (nla_nest_start(skb, attrtype) == NULL) {
1036 nlmsg_trim(skb, start);
1037 return NULL;
1038 }
1039 return start;
1040}
1041
1042/**
1043 * nla_nest_compat_end - Finalize nesting of compat attributes
Pierre Ynardd1ec3b72007-10-10 21:09:48 -07001044 * @skb: socket buffer the attributes are stored in
Patrick McHardy1092cb22007-06-25 13:49:35 -07001045 * @start: container attribute
1046 *
1047 * Corrects the container attribute header to include the all
1048 * appeneded attributes.
1049 *
1050 * Returns the total data length of the skb.
1051 */
1052static inline int nla_nest_compat_end(struct sk_buff *skb, struct nlattr *start)
1053{
1054 struct nlattr *nest = (void *)start + NLMSG_ALIGN(start->nla_len);
1055
1056 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1057 return nla_nest_end(skb, nest);
1058}
1059
1060/**
Thomas Grafbfa83a92005-11-10 02:25:51 +01001061 * nla_nest_cancel - Cancel nesting of attributes
1062 * @skb: socket buffer the message is stored in
1063 * @start: container attribute
1064 *
1065 * Removes the container attribute and including all nested
1066 * attributes. Returns -1.
1067 */
1068static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1069{
Thomas Graffe4944e2006-08-04 23:03:05 -07001070 return nlmsg_trim(skb, start);
Thomas Grafbfa83a92005-11-10 02:25:51 +01001071}
1072
1073/**
Paul Moore4fe5d5c2006-09-25 15:54:03 -07001074 * nla_validate_nested - Validate a stream of nested attributes
1075 * @start: container attribute
1076 * @maxtype: maximum attribute type to be expected
1077 * @policy: validation policy
1078 *
1079 * Validates all attributes in the nested attribute stream against the
1080 * specified policy. Attributes with a type exceeding maxtype will be
1081 * ignored. See documenation of struct nla_policy for more details.
1082 *
1083 * Returns 0 on success or a negative error code.
1084 */
1085static inline int nla_validate_nested(struct nlattr *start, int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -07001086 const struct nla_policy *policy)
Paul Moore4fe5d5c2006-09-25 15:54:03 -07001087{
1088 return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
1089}
1090
1091/**
Thomas Grafbfa83a92005-11-10 02:25:51 +01001092 * nla_for_each_attr - iterate over a stream of attributes
1093 * @pos: loop counter, set to current attribute
1094 * @head: head of attribute stream
1095 * @len: length of attribute stream
1096 * @rem: initialized to len, holds bytes currently remaining in stream
1097 */
1098#define nla_for_each_attr(pos, head, len, rem) \
1099 for (pos = head, rem = len; \
1100 nla_ok(pos, rem); \
1101 pos = nla_next(pos, &(rem)))
1102
Thomas Graffe4944e2006-08-04 23:03:05 -07001103/**
1104 * nla_for_each_nested - iterate over nested attributes
1105 * @pos: loop counter, set to current attribute
1106 * @nla: attribute containing the nested attributes
1107 * @rem: initialized to len, holds bytes currently remaining in stream
1108 */
1109#define nla_for_each_nested(pos, nla, rem) \
1110 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1111
Thomas Grafbfa83a92005-11-10 02:25:51 +01001112#endif