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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
Patrick McHardy01480e12008-01-22 22:10:59 -080094 * nla_append(skb, len, data) append data to skb
Thomas Grafbfa83a92005-11-10 02:25:51 +010095 *
96 * Attribute Construction for Basic Types:
97 * nla_put_u8(skb, type, value) add u8 attribute to skb
98 * nla_put_u16(skb, type, value) add u16 attribute to skb
99 * nla_put_u32(skb, type, value) add u32 attribute to skb
100 * nla_put_u64(skb, type, value) add u64 attribute to skb
101 * nla_put_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 * Exceptions Based Attribute Construction:
106 * NLA_PUT(skb, type, len, data) add attribute to skb
107 * NLA_PUT_U8(skb, type, value) add u8 attribute to skb
108 * NLA_PUT_U16(skb, type, value) add u16 attribute to skb
109 * NLA_PUT_U32(skb, type, value) add u32 attribute to skb
110 * NLA_PUT_U64(skb, type, value) add u64 attribute to skb
111 * NLA_PUT_STRING(skb, type, str) add string attribute to skb
112 * NLA_PUT_FLAG(skb, type) add flag attribute to skb
113 * NLA_PUT_MSECS(skb, type, jiffies) add msecs attribute to skb
114 *
115 * The meaning of these functions is equal to their lower case
116 * variants but they jump to the label nla_put_failure in case
117 * of a failure.
118 *
119 * Nested Attributes Construction:
120 * nla_nest_start(skb, type) start a nested attribute
121 * nla_nest_end(skb, nla) finalize a nested attribute
Patrick McHardy1092cb22007-06-25 13:49:35 -0700122 * nla_nest_compat_start(skb, type, start a nested compat attribute
123 * len, data)
124 * nla_nest_compat_end(skb, type) finalize a nested compat attribute
Thomas Grafbfa83a92005-11-10 02:25:51 +0100125 * nla_nest_cancel(skb, nla) cancel nested attribute construction
126 *
127 * Attribute Length Calculations:
128 * nla_attr_size(payload) length of attribute w/o padding
129 * nla_total_size(payload) length of attribute w/ padding
130 * nla_padlen(payload) length of padding
131 *
132 * Attribute Payload Access:
133 * nla_data(nla) head of attribute payload
134 * nla_len(nla) length of attribute payload
135 *
136 * Attribute Payload Access for Basic Types:
137 * nla_get_u8(nla) get payload for a u8 attribute
138 * nla_get_u16(nla) get payload for a u16 attribute
139 * nla_get_u32(nla) get payload for a u32 attribute
140 * nla_get_u64(nla) get payload for a u64 attribute
141 * nla_get_flag(nla) return 1 if flag is true
142 * nla_get_msecs(nla) get payload for a msecs attribute
143 *
144 * Attribute Misc:
145 * nla_memcpy(dest, nla, count) copy attribute into memory
146 * nla_memcmp(nla, data, size) compare attribute with memory area
147 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
148 * nla_strcmp(nla, str) compare attribute with string
149 *
150 * Attribute Parsing:
151 * nla_ok(nla, remaining) does nla fit into remaining bytes?
152 * nla_next(nla, remaining) get next netlink attribute
153 * nla_validate() validate a stream of attributes
Paul Moore4fe5d5c2006-09-25 15:54:03 -0700154 * nla_validate_nested() validate a stream of nested attributes
Thomas Grafbfa83a92005-11-10 02:25:51 +0100155 * nla_find() find attribute in stream of attributes
Thomas Graffe4944e2006-08-04 23:03:05 -0700156 * nla_find_nested() find attribute in nested attributes
Thomas Grafbfa83a92005-11-10 02:25:51 +0100157 * nla_parse() parse and validate stream of attrs
158 * nla_parse_nested() parse nested attribuets
Patrick McHardy1092cb22007-06-25 13:49:35 -0700159 * nla_parse_nested_compat() parse nested compat attributes
Thomas Grafbfa83a92005-11-10 02:25:51 +0100160 * nla_for_each_attr() loop over all attributes
Paul Moore22acb192006-09-25 15:53:37 -0700161 * nla_for_each_nested() loop over the nested attributes
Thomas Grafbfa83a92005-11-10 02:25:51 +0100162 *=========================================================================
163 */
164
165 /**
166 * Standard attribute types to specify validation policy
167 */
168enum {
169 NLA_UNSPEC,
170 NLA_U8,
171 NLA_U16,
172 NLA_U32,
173 NLA_U64,
174 NLA_STRING,
175 NLA_FLAG,
176 NLA_MSECS,
177 NLA_NESTED,
Patrick McHardy1092cb22007-06-25 13:49:35 -0700178 NLA_NESTED_COMPAT,
Thomas Grafa5531a52006-08-26 20:11:47 -0700179 NLA_NUL_STRING,
Johannes Bergd30045a2007-03-23 11:37:48 -0700180 NLA_BINARY,
Thomas Grafbfa83a92005-11-10 02:25:51 +0100181 __NLA_TYPE_MAX,
182};
183
184#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
185
186/**
187 * struct nla_policy - attribute validation policy
188 * @type: Type of attribute or NLA_UNSPEC
Thomas Grafa5531a52006-08-26 20:11:47 -0700189 * @len: Type specific length of payload
Thomas Grafbfa83a92005-11-10 02:25:51 +0100190 *
191 * Policies are defined as arrays of this struct, the array must be
192 * accessible by attribute type up to the highest identifier to be expected.
193 *
Thomas Grafa5531a52006-08-26 20:11:47 -0700194 * Meaning of `len' field:
195 * NLA_STRING Maximum length of string
196 * NLA_NUL_STRING Maximum length of string (excluding NUL)
197 * NLA_FLAG Unused
Johannes Bergd30045a2007-03-23 11:37:48 -0700198 * NLA_BINARY Maximum length of attribute payload
Patrick McHardy1092cb22007-06-25 13:49:35 -0700199 * NLA_NESTED_COMPAT Exact length of structure payload
Thomas Grafa5531a52006-08-26 20:11:47 -0700200 * All other Exact length of attribute payload
201 *
Thomas Grafbfa83a92005-11-10 02:25:51 +0100202 * Example:
203 * static struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = {
204 * [ATTR_FOO] = { .type = NLA_U16 },
Johannes Bergd30045a2007-03-23 11:37:48 -0700205 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
Thomas Grafa5531a52006-08-26 20:11:47 -0700206 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
Thomas Grafbfa83a92005-11-10 02:25:51 +0100207 * };
208 */
209struct nla_policy {
210 u16 type;
Thomas Grafa5531a52006-08-26 20:11:47 -0700211 u16 len;
Thomas Grafbfa83a92005-11-10 02:25:51 +0100212};
213
Thomas Graf4e902c52006-08-17 18:14:52 -0700214/**
215 * struct nl_info - netlink source information
216 * @nlh: Netlink message header of original request
217 * @pid: Netlink PID of requesting application
218 */
219struct nl_info {
220 struct nlmsghdr *nlh;
Denis V. Lunev4d1169c2008-01-10 03:26:13 -0800221 struct net *nl_net;
Thomas Graf4e902c52006-08-17 18:14:52 -0700222 u32 pid;
223};
224
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700225extern int netlink_rcv_skb(struct sk_buff *skb,
226 int (*cb)(struct sk_buff *,
227 struct nlmsghdr *));
Thomas Graf97676b62006-08-15 00:31:41 -0700228extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb,
229 u32 pid, unsigned int group, int report,
230 gfp_t flags);
Thomas Graf82ace472005-11-10 02:25:53 +0100231
Thomas Grafbfa83a92005-11-10 02:25:51 +0100232extern int nla_validate(struct nlattr *head, int len, int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700233 const struct nla_policy *policy);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100234extern int nla_parse(struct nlattr *tb[], int maxtype,
235 struct nlattr *head, int len,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700236 const struct nla_policy *policy);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100237extern struct nlattr * nla_find(struct nlattr *head, int len, int attrtype);
238extern size_t nla_strlcpy(char *dst, const struct nlattr *nla,
239 size_t dstsize);
240extern int nla_memcpy(void *dest, struct nlattr *src, int count);
241extern int nla_memcmp(const struct nlattr *nla, const void *data,
242 size_t size);
243extern int nla_strcmp(const struct nlattr *nla, const char *str);
244extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype,
245 int attrlen);
Thomas Graffe4944e2006-08-04 23:03:05 -0700246extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100247extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype,
248 int attrlen);
Thomas Graffe4944e2006-08-04 23:03:05 -0700249extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100250extern void __nla_put(struct sk_buff *skb, int attrtype,
251 int attrlen, const void *data);
Thomas Graffe4944e2006-08-04 23:03:05 -0700252extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen,
253 const void *data);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100254extern int nla_put(struct sk_buff *skb, int attrtype,
255 int attrlen, const void *data);
Thomas Graffe4944e2006-08-04 23:03:05 -0700256extern int nla_put_nohdr(struct sk_buff *skb, int attrlen,
257 const void *data);
Patrick McHardy01480e12008-01-22 22:10:59 -0800258extern int nla_append(struct sk_buff *skb, int attrlen,
259 const void *data);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100260
261/**************************************************************************
262 * Netlink Messages
263 **************************************************************************/
264
265/**
266 * nlmsg_msg_size - length of netlink message not including padding
267 * @payload: length of message payload
268 */
269static inline int nlmsg_msg_size(int payload)
270{
271 return NLMSG_HDRLEN + payload;
272}
273
274/**
275 * nlmsg_total_size - length of netlink message including padding
276 * @payload: length of message payload
277 */
278static inline int nlmsg_total_size(int payload)
279{
280 return NLMSG_ALIGN(nlmsg_msg_size(payload));
281}
282
283/**
284 * nlmsg_padlen - length of padding at the message's tail
285 * @payload: length of message payload
286 */
287static inline int nlmsg_padlen(int payload)
288{
289 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
290}
291
292/**
293 * nlmsg_data - head of message payload
294 * @nlh: netlink messsage header
295 */
296static inline void *nlmsg_data(const struct nlmsghdr *nlh)
297{
298 return (unsigned char *) nlh + NLMSG_HDRLEN;
299}
300
301/**
302 * nlmsg_len - length of message payload
303 * @nlh: netlink message header
304 */
305static inline int nlmsg_len(const struct nlmsghdr *nlh)
306{
307 return nlh->nlmsg_len - NLMSG_HDRLEN;
308}
309
310/**
311 * nlmsg_attrdata - head of attributes data
312 * @nlh: netlink message header
313 * @hdrlen: length of family specific header
314 */
315static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
316 int hdrlen)
317{
318 unsigned char *data = nlmsg_data(nlh);
319 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
320}
321
322/**
323 * nlmsg_attrlen - length of attributes data
324 * @nlh: netlink message header
325 * @hdrlen: length of family specific header
326 */
327static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
328{
329 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
330}
331
332/**
333 * nlmsg_ok - check if the netlink message fits into the remaining bytes
334 * @nlh: netlink message header
335 * @remaining: number of bytes remaining in message stream
336 */
337static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
338{
339 return (remaining >= sizeof(struct nlmsghdr) &&
340 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
341 nlh->nlmsg_len <= remaining);
342}
343
344/**
345 * nlmsg_next - next netlink message in message stream
346 * @nlh: netlink message header
347 * @remaining: number of bytes remaining in message stream
348 *
349 * Returns the next netlink message in the message stream and
350 * decrements remaining by the size of the current message.
351 */
352static inline struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining)
353{
354 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
355
356 *remaining -= totlen;
357
358 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
359}
360
361/**
362 * nlmsg_parse - parse attributes of a netlink message
363 * @nlh: netlink message header
364 * @hdrlen: length of family specific header
365 * @tb: destination array with maxtype+1 elements
366 * @maxtype: maximum attribute type to be expected
367 * @policy: validation policy
368 *
369 * See nla_parse()
370 */
371static inline int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen,
372 struct nlattr *tb[], int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700373 const struct nla_policy *policy)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100374{
375 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
376 return -EINVAL;
377
378 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
379 nlmsg_attrlen(nlh, hdrlen), policy);
380}
381
382/**
383 * nlmsg_find_attr - find a specific attribute in a netlink message
384 * @nlh: netlink message header
385 * @hdrlen: length of familiy specific header
386 * @attrtype: type of attribute to look for
387 *
388 * Returns the first attribute which matches the specified type.
389 */
390static inline struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh,
391 int hdrlen, int attrtype)
392{
393 return nla_find(nlmsg_attrdata(nlh, hdrlen),
394 nlmsg_attrlen(nlh, hdrlen), attrtype);
395}
396
397/**
398 * nlmsg_validate - validate a netlink message including attributes
399 * @nlh: netlinket message header
400 * @hdrlen: length of familiy specific header
401 * @maxtype: maximum attribute type to be expected
402 * @policy: validation policy
403 */
404static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700405 const struct nla_policy *policy)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100406{
407 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
408 return -EINVAL;
409
410 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
411 nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
412}
413
414/**
Thomas Graf97676b62006-08-15 00:31:41 -0700415 * nlmsg_report - need to report back to application?
416 * @nlh: netlink message header
417 *
418 * Returns 1 if a report back to the application is requested.
419 */
420static inline int nlmsg_report(struct nlmsghdr *nlh)
421{
422 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
423}
424
425/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100426 * nlmsg_for_each_attr - iterate over a stream of attributes
427 * @pos: loop counter, set to current attribute
428 * @nlh: netlink message header
429 * @hdrlen: length of familiy specific header
430 * @rem: initialized to len, holds bytes currently remaining in stream
431 */
432#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
433 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
434 nlmsg_attrlen(nlh, hdrlen), rem)
435
436#if 0
437/* FIXME: Enable once all users have been converted */
438
439/**
440 * __nlmsg_put - Add a new netlink message to an skb
441 * @skb: socket buffer to store message in
442 * @pid: netlink process id
443 * @seq: sequence number of message
444 * @type: message type
445 * @payload: length of message payload
446 * @flags: message flags
447 *
448 * The caller is responsible to ensure that the skb provides enough
449 * tailroom for both the netlink header and payload.
450 */
451static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid,
452 u32 seq, int type, int payload,
453 int flags)
454{
455 struct nlmsghdr *nlh;
456
457 nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload));
458 nlh->nlmsg_type = type;
459 nlh->nlmsg_len = nlmsg_msg_size(payload);
460 nlh->nlmsg_flags = flags;
461 nlh->nlmsg_pid = pid;
462 nlh->nlmsg_seq = seq;
463
464 memset((unsigned char *) nlmsg_data(nlh) + payload, 0,
465 nlmsg_padlen(payload));
466
467 return nlh;
468}
469#endif
470
471/**
472 * nlmsg_put - Add a new netlink message to an skb
473 * @skb: socket buffer to store message in
474 * @pid: netlink process id
475 * @seq: sequence number of message
476 * @type: message type
477 * @payload: length of message payload
478 * @flags: message flags
479 *
480 * Returns NULL if the tailroom of the skb is insufficient to store
481 * the message header and payload.
482 */
483static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
484 int type, int payload, int flags)
485{
486 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
487 return NULL;
488
489 return __nlmsg_put(skb, pid, seq, type, payload, flags);
490}
491
492/**
493 * nlmsg_put_answer - Add a new callback based netlink message to an skb
494 * @skb: socket buffer to store message in
495 * @cb: netlink callback
496 * @type: message type
497 * @payload: length of message payload
498 * @flags: message flags
499 *
500 * Returns NULL if the tailroom of the skb is insufficient to store
501 * the message header and payload.
502 */
503static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
504 struct netlink_callback *cb,
505 int type, int payload,
506 int flags)
507{
508 return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
509 type, payload, flags);
510}
511
512/**
513 * nlmsg_new - Allocate a new netlink message
Thomas Graf339bf982006-11-10 14:10:15 -0800514 * @payload: size of the message payload
Thomas Graffe4944e2006-08-04 23:03:05 -0700515 * @flags: the type of memory to allocate.
Thomas Grafbfa83a92005-11-10 02:25:51 +0100516 *
Thomas Graf339bf982006-11-10 14:10:15 -0800517 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
518 * and a good default is needed.
Thomas Grafbfa83a92005-11-10 02:25:51 +0100519 */
Thomas Graf339bf982006-11-10 14:10:15 -0800520static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100521{
Thomas Graf339bf982006-11-10 14:10:15 -0800522 return alloc_skb(nlmsg_total_size(payload), flags);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100523}
524
525/**
526 * nlmsg_end - Finalize a netlink message
527 * @skb: socket buffer the message is stored in
528 * @nlh: netlink message header
529 *
530 * Corrects the netlink message header to include the appeneded
531 * attributes. Only necessary if attributes have been added to
532 * the message.
533 *
534 * Returns the total data length of the skb.
535 */
536static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
537{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700538 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
Thomas Grafbfa83a92005-11-10 02:25:51 +0100539
540 return skb->len;
541}
542
543/**
Thomas Graffe4944e2006-08-04 23:03:05 -0700544 * nlmsg_get_pos - return current position in netlink message
545 * @skb: socket buffer the message is stored in
546 *
547 * Returns a pointer to the current tail of the message.
548 */
549static inline void *nlmsg_get_pos(struct sk_buff *skb)
550{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700551 return skb_tail_pointer(skb);
Thomas Graffe4944e2006-08-04 23:03:05 -0700552}
553
554/**
555 * nlmsg_trim - Trim message to a mark
556 * @skb: socket buffer the message is stored in
557 * @mark: mark to trim to
558 *
559 * Trims the message to the provided mark. Returns -1.
560 */
Arnaldo Carvalho de Melodc5fc572007-03-25 23:06:12 -0700561static inline int nlmsg_trim(struct sk_buff *skb, const void *mark)
Thomas Graffe4944e2006-08-04 23:03:05 -0700562{
563 if (mark)
564 skb_trim(skb, (unsigned char *) mark - skb->data);
565
566 return -1;
567}
568
569/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100570 * nlmsg_cancel - Cancel construction of a netlink message
571 * @skb: socket buffer the message is stored in
572 * @nlh: netlink message header
573 *
574 * Removes the complete netlink message including all
575 * attributes from the socket buffer again. Returns -1.
576 */
577static inline int nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
578{
Thomas Graffe4944e2006-08-04 23:03:05 -0700579 return nlmsg_trim(skb, nlh);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100580}
581
582/**
583 * nlmsg_free - free a netlink message
584 * @skb: socket buffer of netlink message
585 */
586static inline void nlmsg_free(struct sk_buff *skb)
587{
588 kfree_skb(skb);
589}
590
591/**
592 * nlmsg_multicast - multicast a netlink message
593 * @sk: netlink socket to spread messages to
594 * @skb: netlink message as socket buffer
595 * @pid: own netlink pid to avoid sending to yourself
596 * @group: multicast group id
Thomas Grafd387f6a2006-08-15 00:31:06 -0700597 * @flags: allocation flags
Thomas Grafbfa83a92005-11-10 02:25:51 +0100598 */
599static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
Thomas Grafd387f6a2006-08-15 00:31:06 -0700600 u32 pid, unsigned int group, gfp_t flags)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100601{
602 int err;
603
604 NETLINK_CB(skb).dst_group = group;
605
Thomas Grafd387f6a2006-08-15 00:31:06 -0700606 err = netlink_broadcast(sk, skb, pid, group, flags);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100607 if (err > 0)
608 err = 0;
609
610 return err;
611}
612
613/**
614 * nlmsg_unicast - unicast a netlink message
615 * @sk: netlink socket to spread message to
616 * @skb: netlink message as socket buffer
617 * @pid: netlink pid of the destination socket
618 */
619static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid)
620{
621 int err;
622
623 err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT);
624 if (err > 0)
625 err = 0;
626
627 return err;
628}
629
630/**
631 * nlmsg_for_each_msg - iterate over a stream of messages
632 * @pos: loop counter, set to current message
633 * @head: head of message stream
634 * @len: length of message stream
635 * @rem: initialized to len, holds bytes currently remaining in stream
636 */
637#define nlmsg_for_each_msg(pos, head, len, rem) \
638 for (pos = head, rem = len; \
639 nlmsg_ok(pos, rem); \
640 pos = nlmsg_next(pos, &(rem)))
641
642/**************************************************************************
643 * Netlink Attributes
644 **************************************************************************/
645
646/**
647 * nla_attr_size - length of attribute not including padding
648 * @payload: length of payload
649 */
650static inline int nla_attr_size(int payload)
651{
652 return NLA_HDRLEN + payload;
653}
654
655/**
656 * nla_total_size - total length of attribute including padding
657 * @payload: length of payload
658 */
659static inline int nla_total_size(int payload)
660{
661 return NLA_ALIGN(nla_attr_size(payload));
662}
663
664/**
665 * nla_padlen - length of padding at the tail of attribute
666 * @payload: length of payload
667 */
668static inline int nla_padlen(int payload)
669{
670 return nla_total_size(payload) - nla_attr_size(payload);
671}
672
673/**
Thomas Graf8f4c1f92007-09-12 14:44:36 +0200674 * nla_type - attribute type
675 * @nla: netlink attribute
676 */
677static inline int nla_type(const struct nlattr *nla)
678{
679 return nla->nla_type & NLA_TYPE_MASK;
680}
681
682/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100683 * nla_data - head of payload
684 * @nla: netlink attribute
685 */
686static inline void *nla_data(const struct nlattr *nla)
687{
688 return (char *) nla + NLA_HDRLEN;
689}
690
691/**
692 * nla_len - length of payload
693 * @nla: netlink attribute
694 */
695static inline int nla_len(const struct nlattr *nla)
696{
697 return nla->nla_len - NLA_HDRLEN;
698}
699
700/**
701 * nla_ok - check if the netlink attribute fits into the remaining bytes
702 * @nla: netlink attribute
703 * @remaining: number of bytes remaining in attribute stream
704 */
705static inline int nla_ok(const struct nlattr *nla, int remaining)
706{
707 return remaining >= sizeof(*nla) &&
708 nla->nla_len >= sizeof(*nla) &&
709 nla->nla_len <= remaining;
710}
711
712/**
Pierre Ynardd1ec3b72007-10-10 21:09:48 -0700713 * nla_next - next netlink attribute in attribute stream
Thomas Grafbfa83a92005-11-10 02:25:51 +0100714 * @nla: netlink attribute
715 * @remaining: number of bytes remaining in attribute stream
716 *
717 * Returns the next netlink attribute in the attribute stream and
718 * decrements remaining by the size of the current attribute.
719 */
720static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
721{
722 int totlen = NLA_ALIGN(nla->nla_len);
723
724 *remaining -= totlen;
725 return (struct nlattr *) ((char *) nla + totlen);
726}
727
728/**
Thomas Graffe4944e2006-08-04 23:03:05 -0700729 * nla_find_nested - find attribute in a set of nested attributes
730 * @nla: attribute containing the nested attributes
731 * @attrtype: type of attribute to look for
732 *
733 * Returns the first attribute which matches the specified type.
734 */
735static inline struct nlattr *nla_find_nested(struct nlattr *nla, int attrtype)
736{
737 return nla_find(nla_data(nla), nla_len(nla), attrtype);
738}
739
740/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100741 * nla_parse_nested - parse nested attributes
742 * @tb: destination array with maxtype+1 elements
743 * @maxtype: maximum attribute type to be expected
744 * @nla: attribute containing the nested attributes
745 * @policy: validation policy
746 *
747 * See nla_parse()
748 */
749static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
750 struct nlattr *nla,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700751 const struct nla_policy *policy)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100752{
753 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
754}
Patrick McHardy1092cb22007-06-25 13:49:35 -0700755
756/**
757 * nla_parse_nested_compat - parse nested compat attributes
758 * @tb: destination array with maxtype+1 elements
759 * @maxtype: maximum attribute type to be expected
760 * @nla: attribute containing the nested attributes
761 * @data: pointer to point to contained structure
762 * @len: length of contained structure
763 * @policy: validation policy
764 *
765 * Parse a nested compat attribute. The compat attribute contains a structure
766 * and optionally a set of nested attributes. On success the data pointer
767 * points to the nested data and tb contains the parsed attributes
768 * (see nla_parse).
769 */
770static inline int __nla_parse_nested_compat(struct nlattr *tb[], int maxtype,
771 struct nlattr *nla,
772 const struct nla_policy *policy,
773 int len)
774{
775 if (nla_len(nla) < len)
776 return -1;
777 if (nla_len(nla) >= NLA_ALIGN(len) + sizeof(struct nlattr))
778 return nla_parse_nested(tb, maxtype,
779 nla_data(nla) + NLA_ALIGN(len),
780 policy);
781 memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
782 return 0;
783}
784
785#define nla_parse_nested_compat(tb, maxtype, nla, policy, data, len) \
786({ data = nla_len(nla) >= len ? nla_data(nla) : NULL; \
787 __nla_parse_nested_compat(tb, maxtype, nla, policy, len); })
Thomas Grafbfa83a92005-11-10 02:25:51 +0100788/**
Pierre Ynardd1ec3b72007-10-10 21:09:48 -0700789 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
Thomas Grafbfa83a92005-11-10 02:25:51 +0100790 * @skb: socket buffer to add attribute to
791 * @attrtype: attribute type
792 * @value: numeric value
793 */
794static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
795{
796 return nla_put(skb, attrtype, sizeof(u8), &value);
797}
798
799/**
800 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
801 * @skb: socket buffer to add attribute to
802 * @attrtype: attribute type
803 * @value: numeric value
804 */
805static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
806{
807 return nla_put(skb, attrtype, sizeof(u16), &value);
808}
809
810/**
811 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
812 * @skb: socket buffer to add attribute to
813 * @attrtype: attribute type
814 * @value: numeric value
815 */
816static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
817{
818 return nla_put(skb, attrtype, sizeof(u32), &value);
819}
820
821/**
822 * nla_put_64 - Add a u64 netlink attribute to a socket buffer
823 * @skb: socket buffer to add attribute to
824 * @attrtype: attribute type
825 * @value: numeric value
826 */
827static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
828{
829 return nla_put(skb, attrtype, sizeof(u64), &value);
830}
831
832/**
833 * nla_put_string - Add a string netlink attribute to a socket buffer
834 * @skb: socket buffer to add attribute to
835 * @attrtype: attribute type
836 * @str: NUL terminated string
837 */
838static inline int nla_put_string(struct sk_buff *skb, int attrtype,
839 const char *str)
840{
841 return nla_put(skb, attrtype, strlen(str) + 1, str);
842}
843
844/**
845 * nla_put_flag - Add a flag netlink attribute to a socket buffer
846 * @skb: socket buffer to add attribute to
847 * @attrtype: attribute type
848 */
849static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
850{
851 return nla_put(skb, attrtype, 0, NULL);
852}
853
854/**
855 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer
856 * @skb: socket buffer to add attribute to
857 * @attrtype: attribute type
858 * @jiffies: number of msecs in jiffies
859 */
860static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
861 unsigned long jiffies)
862{
863 u64 tmp = jiffies_to_msecs(jiffies);
864 return nla_put(skb, attrtype, sizeof(u64), &tmp);
865}
866
867#define NLA_PUT(skb, attrtype, attrlen, data) \
868 do { \
Patrick McHardyf4d900a2007-12-05 03:31:53 -0800869 if (unlikely(nla_put(skb, attrtype, attrlen, data) < 0)) \
Thomas Grafbfa83a92005-11-10 02:25:51 +0100870 goto nla_put_failure; \
871 } while(0)
872
873#define NLA_PUT_TYPE(skb, type, attrtype, value) \
874 do { \
875 type __tmp = value; \
876 NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \
877 } while(0)
878
879#define NLA_PUT_U8(skb, attrtype, value) \
880 NLA_PUT_TYPE(skb, u8, attrtype, value)
881
882#define NLA_PUT_U16(skb, attrtype, value) \
883 NLA_PUT_TYPE(skb, u16, attrtype, value)
884
Thomas Graf4a89c252006-11-24 17:14:51 -0800885#define NLA_PUT_LE16(skb, attrtype, value) \
886 NLA_PUT_TYPE(skb, __le16, attrtype, value)
887
Patrick McHardy838965b2007-12-17 22:29:26 -0800888#define NLA_PUT_BE16(skb, attrtype, value) \
889 NLA_PUT_TYPE(skb, __be16, attrtype, value)
890
Thomas Grafbfa83a92005-11-10 02:25:51 +0100891#define NLA_PUT_U32(skb, attrtype, value) \
892 NLA_PUT_TYPE(skb, u32, attrtype, value)
893
Al Viro00012e52006-09-26 22:14:41 -0700894#define NLA_PUT_BE32(skb, attrtype, value) \
895 NLA_PUT_TYPE(skb, __be32, attrtype, value)
896
Thomas Grafbfa83a92005-11-10 02:25:51 +0100897#define NLA_PUT_U64(skb, attrtype, value) \
898 NLA_PUT_TYPE(skb, u64, attrtype, value)
899
900#define NLA_PUT_STRING(skb, attrtype, value) \
901 NLA_PUT(skb, attrtype, strlen(value) + 1, value)
902
Johannes Bergff5dfe72006-08-26 19:17:53 -0700903#define NLA_PUT_FLAG(skb, attrtype) \
Thomas Grafbfa83a92005-11-10 02:25:51 +0100904 NLA_PUT(skb, attrtype, 0, NULL)
905
906#define NLA_PUT_MSECS(skb, attrtype, jiffies) \
907 NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies))
908
909/**
910 * nla_get_u32 - return payload of u32 attribute
911 * @nla: u32 netlink attribute
912 */
913static inline u32 nla_get_u32(struct nlattr *nla)
914{
915 return *(u32 *) nla_data(nla);
916}
917
918/**
Al Viro00012e52006-09-26 22:14:41 -0700919 * nla_get_be32 - return payload of __be32 attribute
920 * @nla: __be32 netlink attribute
921 */
922static inline __be32 nla_get_be32(struct nlattr *nla)
923{
924 return *(__be32 *) nla_data(nla);
925}
926
927/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100928 * nla_get_u16 - return payload of u16 attribute
929 * @nla: u16 netlink attribute
930 */
931static inline u16 nla_get_u16(struct nlattr *nla)
932{
933 return *(u16 *) nla_data(nla);
934}
935
936/**
Patrick McHardy838965b2007-12-17 22:29:26 -0800937 * nla_get_be16 - return payload of __be16 attribute
938 * @nla: __be16 netlink attribute
939 */
940static inline __be16 nla_get_be16(struct nlattr *nla)
941{
942 return *(__be16 *) nla_data(nla);
943}
944
945/**
Thomas Graf4a89c252006-11-24 17:14:51 -0800946 * nla_get_le16 - return payload of __le16 attribute
947 * @nla: __le16 netlink attribute
948 */
949static inline __le16 nla_get_le16(struct nlattr *nla)
950{
951 return *(__le16 *) nla_data(nla);
952}
953
954/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100955 * nla_get_u8 - return payload of u8 attribute
956 * @nla: u8 netlink attribute
957 */
958static inline u8 nla_get_u8(struct nlattr *nla)
959{
960 return *(u8 *) nla_data(nla);
961}
962
963/**
964 * nla_get_u64 - return payload of u64 attribute
965 * @nla: u64 netlink attribute
966 */
967static inline u64 nla_get_u64(struct nlattr *nla)
968{
969 u64 tmp;
970
971 nla_memcpy(&tmp, nla, sizeof(tmp));
972
973 return tmp;
974}
975
976/**
977 * nla_get_flag - return payload of flag attribute
978 * @nla: flag netlink attribute
979 */
980static inline int nla_get_flag(struct nlattr *nla)
981{
982 return !!nla;
983}
984
985/**
986 * nla_get_msecs - return payload of msecs attribute
987 * @nla: msecs netlink attribute
988 *
989 * Returns the number of milliseconds in jiffies.
990 */
991static inline unsigned long nla_get_msecs(struct nlattr *nla)
992{
993 u64 msecs = nla_get_u64(nla);
994
995 return msecs_to_jiffies((unsigned long) msecs);
996}
997
998/**
999 * nla_nest_start - Start a new level of nested attributes
1000 * @skb: socket buffer to add attributes to
1001 * @attrtype: attribute type of container
1002 *
1003 * Returns the container attribute
1004 */
1005static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1006{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001007 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
Thomas Grafbfa83a92005-11-10 02:25:51 +01001008
1009 if (nla_put(skb, attrtype, 0, NULL) < 0)
1010 return NULL;
1011
1012 return start;
1013}
1014
1015/**
1016 * nla_nest_end - Finalize nesting of attributes
Pierre Ynardd1ec3b72007-10-10 21:09:48 -07001017 * @skb: socket buffer the attributes are stored in
Thomas Grafbfa83a92005-11-10 02:25:51 +01001018 * @start: container attribute
1019 *
1020 * Corrects the container attribute header to include the all
1021 * appeneded attributes.
1022 *
1023 * Returns the total data length of the skb.
1024 */
1025static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1026{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001027 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
Thomas Grafbfa83a92005-11-10 02:25:51 +01001028 return skb->len;
1029}
1030
1031/**
Patrick McHardy1092cb22007-06-25 13:49:35 -07001032 * nla_nest_compat_start - Start a new level of nested compat attributes
1033 * @skb: socket buffer to add attributes to
1034 * @attrtype: attribute type of container
1035 * @attrlen: length of structure
1036 * @data: pointer to structure
1037 *
1038 * Start a nested compat attribute that contains both a structure and
1039 * a set of nested attributes.
1040 *
1041 * Returns the container attribute
1042 */
1043static inline struct nlattr *nla_nest_compat_start(struct sk_buff *skb,
1044 int attrtype, int attrlen,
1045 const void *data)
1046{
1047 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1048
1049 if (nla_put(skb, attrtype, attrlen, data) < 0)
1050 return NULL;
1051 if (nla_nest_start(skb, attrtype) == NULL) {
1052 nlmsg_trim(skb, start);
1053 return NULL;
1054 }
1055 return start;
1056}
1057
1058/**
1059 * nla_nest_compat_end - Finalize nesting of compat attributes
Pierre Ynardd1ec3b72007-10-10 21:09:48 -07001060 * @skb: socket buffer the attributes are stored in
Patrick McHardy1092cb22007-06-25 13:49:35 -07001061 * @start: container attribute
1062 *
1063 * Corrects the container attribute header to include the all
1064 * appeneded attributes.
1065 *
1066 * Returns the total data length of the skb.
1067 */
1068static inline int nla_nest_compat_end(struct sk_buff *skb, struct nlattr *start)
1069{
1070 struct nlattr *nest = (void *)start + NLMSG_ALIGN(start->nla_len);
1071
1072 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1073 return nla_nest_end(skb, nest);
1074}
1075
1076/**
Thomas Grafbfa83a92005-11-10 02:25:51 +01001077 * nla_nest_cancel - Cancel nesting of attributes
1078 * @skb: socket buffer the message is stored in
1079 * @start: container attribute
1080 *
1081 * Removes the container attribute and including all nested
1082 * attributes. Returns -1.
1083 */
1084static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1085{
Thomas Graffe4944e2006-08-04 23:03:05 -07001086 return nlmsg_trim(skb, start);
Thomas Grafbfa83a92005-11-10 02:25:51 +01001087}
1088
1089/**
Paul Moore4fe5d5c2006-09-25 15:54:03 -07001090 * nla_validate_nested - Validate a stream of nested attributes
1091 * @start: container attribute
1092 * @maxtype: maximum attribute type to be expected
1093 * @policy: validation policy
1094 *
1095 * Validates all attributes in the nested attribute stream against the
1096 * specified policy. Attributes with a type exceeding maxtype will be
1097 * ignored. See documenation of struct nla_policy for more details.
1098 *
1099 * Returns 0 on success or a negative error code.
1100 */
1101static inline int nla_validate_nested(struct nlattr *start, int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -07001102 const struct nla_policy *policy)
Paul Moore4fe5d5c2006-09-25 15:54:03 -07001103{
1104 return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
1105}
1106
1107/**
Thomas Grafbfa83a92005-11-10 02:25:51 +01001108 * nla_for_each_attr - iterate over a stream of attributes
1109 * @pos: loop counter, set to current attribute
1110 * @head: head of attribute stream
1111 * @len: length of attribute stream
1112 * @rem: initialized to len, holds bytes currently remaining in stream
1113 */
1114#define nla_for_each_attr(pos, head, len, rem) \
1115 for (pos = head, rem = len; \
1116 nla_ok(pos, rem); \
1117 pos = nla_next(pos, &(rem)))
1118
Thomas Graffe4944e2006-08-04 23:03:05 -07001119/**
1120 * nla_for_each_nested - iterate over nested attributes
1121 * @pos: loop counter, set to current attribute
1122 * @nla: attribute containing the nested attributes
1123 * @rem: initialized to len, holds bytes currently remaining in stream
1124 */
1125#define nla_for_each_nested(pos, nla, rem) \
1126 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1127
Thomas Grafbfa83a92005-11-10 02:25:51 +01001128#endif