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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
122 * nla_nest_cancel(skb, nla) cancel nested attribute construction
123 *
124 * Attribute Length Calculations:
125 * nla_attr_size(payload) length of attribute w/o padding
126 * nla_total_size(payload) length of attribute w/ padding
127 * nla_padlen(payload) length of padding
128 *
129 * Attribute Payload Access:
130 * nla_data(nla) head of attribute payload
131 * nla_len(nla) length of attribute payload
132 *
133 * Attribute Payload Access for Basic Types:
134 * nla_get_u8(nla) get payload for a u8 attribute
135 * nla_get_u16(nla) get payload for a u16 attribute
136 * nla_get_u32(nla) get payload for a u32 attribute
137 * nla_get_u64(nla) get payload for a u64 attribute
138 * nla_get_flag(nla) return 1 if flag is true
139 * nla_get_msecs(nla) get payload for a msecs attribute
140 *
141 * Attribute Misc:
142 * nla_memcpy(dest, nla, count) copy attribute into memory
143 * nla_memcmp(nla, data, size) compare attribute with memory area
144 * nla_strlcpy(dst, nla, size) copy attribute to a sized string
145 * nla_strcmp(nla, str) compare attribute with string
146 *
147 * Attribute Parsing:
148 * nla_ok(nla, remaining) does nla fit into remaining bytes?
149 * nla_next(nla, remaining) get next netlink attribute
150 * nla_validate() validate a stream of attributes
Paul Moore4fe5d5c2006-09-25 15:54:03 -0700151 * nla_validate_nested() validate a stream of nested attributes
Thomas Grafbfa83a92005-11-10 02:25:51 +0100152 * nla_find() find attribute in stream of attributes
Thomas Graffe4944e2006-08-04 23:03:05 -0700153 * nla_find_nested() find attribute in nested attributes
Thomas Grafbfa83a92005-11-10 02:25:51 +0100154 * nla_parse() parse and validate stream of attrs
155 * nla_parse_nested() parse nested attribuets
156 * nla_for_each_attr() loop over all attributes
Paul Moore22acb192006-09-25 15:53:37 -0700157 * nla_for_each_nested() loop over the nested attributes
Thomas Grafbfa83a92005-11-10 02:25:51 +0100158 *=========================================================================
159 */
160
161 /**
162 * Standard attribute types to specify validation policy
163 */
164enum {
165 NLA_UNSPEC,
166 NLA_U8,
167 NLA_U16,
168 NLA_U32,
169 NLA_U64,
170 NLA_STRING,
171 NLA_FLAG,
172 NLA_MSECS,
173 NLA_NESTED,
Patrick McHardy1092cb22007-06-25 13:49:35 -0700174 NLA_NESTED_COMPAT,
Thomas Grafa5531a52006-08-26 20:11:47 -0700175 NLA_NUL_STRING,
Johannes Bergd30045a2007-03-23 11:37:48 -0700176 NLA_BINARY,
Thomas Grafbfa83a92005-11-10 02:25:51 +0100177 __NLA_TYPE_MAX,
178};
179
180#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
181
182/**
183 * struct nla_policy - attribute validation policy
184 * @type: Type of attribute or NLA_UNSPEC
Thomas Grafa5531a52006-08-26 20:11:47 -0700185 * @len: Type specific length of payload
Thomas Grafbfa83a92005-11-10 02:25:51 +0100186 *
187 * Policies are defined as arrays of this struct, the array must be
188 * accessible by attribute type up to the highest identifier to be expected.
189 *
Thomas Grafa5531a52006-08-26 20:11:47 -0700190 * Meaning of `len' field:
191 * NLA_STRING Maximum length of string
192 * NLA_NUL_STRING Maximum length of string (excluding NUL)
193 * NLA_FLAG Unused
Johannes Bergd30045a2007-03-23 11:37:48 -0700194 * NLA_BINARY Maximum length of attribute payload
Patrick McHardy1092cb22007-06-25 13:49:35 -0700195 * NLA_NESTED_COMPAT Exact length of structure payload
Thomas Grafa5531a52006-08-26 20:11:47 -0700196 * All other Exact length of attribute payload
197 *
Thomas Grafbfa83a92005-11-10 02:25:51 +0100198 * Example:
Alexey Dobriyanb54452b2010-02-18 08:14:31 +0000199 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
Thomas Grafbfa83a92005-11-10 02:25:51 +0100200 * [ATTR_FOO] = { .type = NLA_U16 },
Johannes Bergd30045a2007-03-23 11:37:48 -0700201 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
Thomas Grafa5531a52006-08-26 20:11:47 -0700202 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
Thomas Grafbfa83a92005-11-10 02:25:51 +0100203 * };
204 */
205struct nla_policy {
206 u16 type;
Thomas Grafa5531a52006-08-26 20:11:47 -0700207 u16 len;
Thomas Grafbfa83a92005-11-10 02:25:51 +0100208};
209
Thomas Graf4e902c52006-08-17 18:14:52 -0700210/**
211 * struct nl_info - netlink source information
212 * @nlh: Netlink message header of original request
213 * @pid: Netlink PID of requesting application
214 */
215struct nl_info {
216 struct nlmsghdr *nlh;
Denis V. Lunev4d1169c2008-01-10 03:26:13 -0800217 struct net *nl_net;
Thomas Graf4e902c52006-08-17 18:14:52 -0700218 u32 pid;
219};
220
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700221extern int netlink_rcv_skb(struct sk_buff *skb,
222 int (*cb)(struct sk_buff *,
223 struct nlmsghdr *));
Thomas Graf97676b62006-08-15 00:31:41 -0700224extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb,
225 u32 pid, unsigned int group, int report,
226 gfp_t flags);
Thomas Graf82ace472005-11-10 02:25:53 +0100227
Thomas Grafbfa83a92005-11-10 02:25:51 +0100228extern int nla_validate(struct nlattr *head, int len, int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700229 const struct nla_policy *policy);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100230extern int nla_parse(struct nlattr *tb[], int maxtype,
231 struct nlattr *head, int len,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700232 const struct nla_policy *policy);
Holger Eitzenbergere487eb92009-03-25 18:26:30 +0100233extern int nla_policy_len(const struct nla_policy *, int);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100234extern struct nlattr * nla_find(struct nlattr *head, int len, int attrtype);
235extern size_t nla_strlcpy(char *dst, const struct nlattr *nla,
236 size_t dstsize);
Patrick McHardyb057efd2008-10-28 11:59:11 -0700237extern int nla_memcpy(void *dest, const struct nlattr *src, int count);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100238extern int nla_memcmp(const struct nlattr *nla, const void *data,
239 size_t size);
240extern int nla_strcmp(const struct nlattr *nla, const char *str);
241extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype,
242 int attrlen);
Thomas Graffe4944e2006-08-04 23:03:05 -0700243extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100244extern 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 void __nla_put(struct sk_buff *skb, int attrtype,
248 int attrlen, const void *data);
Thomas Graffe4944e2006-08-04 23:03:05 -0700249extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen,
250 const void *data);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100251extern int nla_put(struct sk_buff *skb, int attrtype,
252 int attrlen, const void *data);
Thomas Graffe4944e2006-08-04 23:03:05 -0700253extern int nla_put_nohdr(struct sk_buff *skb, int attrlen,
254 const void *data);
Patrick McHardy01480e12008-01-22 22:10:59 -0800255extern int nla_append(struct sk_buff *skb, int attrlen,
256 const void *data);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100257
258/**************************************************************************
259 * Netlink Messages
260 **************************************************************************/
261
262/**
263 * nlmsg_msg_size - length of netlink message not including padding
264 * @payload: length of message payload
265 */
266static inline int nlmsg_msg_size(int payload)
267{
268 return NLMSG_HDRLEN + payload;
269}
270
271/**
272 * nlmsg_total_size - length of netlink message including padding
273 * @payload: length of message payload
274 */
275static inline int nlmsg_total_size(int payload)
276{
277 return NLMSG_ALIGN(nlmsg_msg_size(payload));
278}
279
280/**
281 * nlmsg_padlen - length of padding at the message's tail
282 * @payload: length of message payload
283 */
284static inline int nlmsg_padlen(int payload)
285{
286 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
287}
288
289/**
290 * nlmsg_data - head of message payload
291 * @nlh: netlink messsage header
292 */
293static inline void *nlmsg_data(const struct nlmsghdr *nlh)
294{
295 return (unsigned char *) nlh + NLMSG_HDRLEN;
296}
297
298/**
299 * nlmsg_len - length of message payload
300 * @nlh: netlink message header
301 */
302static inline int nlmsg_len(const struct nlmsghdr *nlh)
303{
304 return nlh->nlmsg_len - NLMSG_HDRLEN;
305}
306
307/**
308 * nlmsg_attrdata - head of attributes data
309 * @nlh: netlink message header
310 * @hdrlen: length of family specific header
311 */
312static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
313 int hdrlen)
314{
315 unsigned char *data = nlmsg_data(nlh);
316 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
317}
318
319/**
320 * nlmsg_attrlen - length of attributes data
321 * @nlh: netlink message header
322 * @hdrlen: length of family specific header
323 */
324static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
325{
326 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
327}
328
329/**
330 * nlmsg_ok - check if the netlink message fits into the remaining bytes
331 * @nlh: netlink message header
332 * @remaining: number of bytes remaining in message stream
333 */
334static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
335{
Vegard Nossum619e8032008-12-25 17:21:17 -0800336 return (remaining >= (int) sizeof(struct nlmsghdr) &&
Thomas Grafbfa83a92005-11-10 02:25:51 +0100337 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
338 nlh->nlmsg_len <= remaining);
339}
340
341/**
342 * nlmsg_next - next netlink message in message stream
343 * @nlh: netlink message header
344 * @remaining: number of bytes remaining in message stream
345 *
346 * Returns the next netlink message in the message stream and
347 * decrements remaining by the size of the current message.
348 */
349static inline struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining)
350{
351 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
352
353 *remaining -= totlen;
354
355 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
356}
357
358/**
359 * nlmsg_parse - parse attributes of a netlink message
360 * @nlh: netlink message header
361 * @hdrlen: length of family specific header
362 * @tb: destination array with maxtype+1 elements
363 * @maxtype: maximum attribute type to be expected
364 * @policy: validation policy
365 *
366 * See nla_parse()
367 */
Patrick McHardy3a6c2b42009-08-25 16:07:40 +0200368static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
Thomas Grafbfa83a92005-11-10 02:25:51 +0100369 struct nlattr *tb[], int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700370 const struct nla_policy *policy)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100371{
372 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
373 return -EINVAL;
374
375 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
376 nlmsg_attrlen(nlh, hdrlen), policy);
377}
378
379/**
380 * nlmsg_find_attr - find a specific attribute in a netlink message
381 * @nlh: netlink message header
382 * @hdrlen: length of familiy specific header
383 * @attrtype: type of attribute to look for
384 *
385 * Returns the first attribute which matches the specified type.
386 */
387static inline struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh,
388 int hdrlen, int attrtype)
389{
390 return nla_find(nlmsg_attrdata(nlh, hdrlen),
391 nlmsg_attrlen(nlh, hdrlen), attrtype);
392}
393
394/**
395 * nlmsg_validate - validate a netlink message including attributes
396 * @nlh: netlinket message header
397 * @hdrlen: length of familiy specific header
398 * @maxtype: maximum attribute type to be expected
399 * @policy: validation policy
400 */
401static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700402 const struct nla_policy *policy)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100403{
404 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
405 return -EINVAL;
406
407 return nla_validate(nlmsg_attrdata(nlh, hdrlen),
408 nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
409}
410
411/**
Thomas Graf97676b62006-08-15 00:31:41 -0700412 * nlmsg_report - need to report back to application?
413 * @nlh: netlink message header
414 *
415 * Returns 1 if a report back to the application is requested.
416 */
Patrick McHardy3a6c2b42009-08-25 16:07:40 +0200417static inline int nlmsg_report(const struct nlmsghdr *nlh)
Thomas Graf97676b62006-08-15 00:31:41 -0700418{
419 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
420}
421
422/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100423 * nlmsg_for_each_attr - iterate over a stream of attributes
424 * @pos: loop counter, set to current attribute
425 * @nlh: netlink message header
426 * @hdrlen: length of familiy specific header
427 * @rem: initialized to len, holds bytes currently remaining in stream
428 */
429#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
430 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
431 nlmsg_attrlen(nlh, hdrlen), rem)
432
433#if 0
434/* FIXME: Enable once all users have been converted */
435
436/**
437 * __nlmsg_put - Add a new netlink message to an skb
438 * @skb: socket buffer to store message in
439 * @pid: netlink process id
440 * @seq: sequence number of message
441 * @type: message type
442 * @payload: length of message payload
443 * @flags: message flags
444 *
445 * The caller is responsible to ensure that the skb provides enough
446 * tailroom for both the netlink header and payload.
447 */
448static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid,
449 u32 seq, int type, int payload,
450 int flags)
451{
452 struct nlmsghdr *nlh;
453
454 nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload));
455 nlh->nlmsg_type = type;
456 nlh->nlmsg_len = nlmsg_msg_size(payload);
457 nlh->nlmsg_flags = flags;
458 nlh->nlmsg_pid = pid;
459 nlh->nlmsg_seq = seq;
460
461 memset((unsigned char *) nlmsg_data(nlh) + payload, 0,
462 nlmsg_padlen(payload));
463
464 return nlh;
465}
466#endif
467
468/**
469 * nlmsg_put - Add a new netlink message to an skb
470 * @skb: socket buffer to store message in
471 * @pid: netlink process id
472 * @seq: sequence number of message
473 * @type: message type
474 * @payload: length of message payload
475 * @flags: message flags
476 *
477 * Returns NULL if the tailroom of the skb is insufficient to store
478 * the message header and payload.
479 */
480static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
481 int type, int payload, int flags)
482{
483 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
484 return NULL;
485
486 return __nlmsg_put(skb, pid, seq, type, payload, flags);
487}
488
489/**
490 * nlmsg_put_answer - Add a new callback based netlink message to an skb
491 * @skb: socket buffer to store message in
492 * @cb: netlink callback
493 * @type: message type
494 * @payload: length of message payload
495 * @flags: message flags
496 *
497 * Returns NULL if the tailroom of the skb is insufficient to store
498 * the message header and payload.
499 */
500static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
501 struct netlink_callback *cb,
502 int type, int payload,
503 int flags)
504{
505 return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
506 type, payload, flags);
507}
508
509/**
510 * nlmsg_new - Allocate a new netlink message
Thomas Graf339bf982006-11-10 14:10:15 -0800511 * @payload: size of the message payload
Thomas Graffe4944e2006-08-04 23:03:05 -0700512 * @flags: the type of memory to allocate.
Thomas Grafbfa83a92005-11-10 02:25:51 +0100513 *
Thomas Graf339bf982006-11-10 14:10:15 -0800514 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
515 * and a good default is needed.
Thomas Grafbfa83a92005-11-10 02:25:51 +0100516 */
Thomas Graf339bf982006-11-10 14:10:15 -0800517static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100518{
Thomas Graf339bf982006-11-10 14:10:15 -0800519 return alloc_skb(nlmsg_total_size(payload), flags);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100520}
521
522/**
523 * nlmsg_end - Finalize a netlink message
524 * @skb: socket buffer the message is stored in
525 * @nlh: netlink message header
526 *
527 * Corrects the netlink message header to include the appeneded
528 * attributes. Only necessary if attributes have been added to
529 * the message.
530 *
531 * Returns the total data length of the skb.
532 */
533static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
534{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700535 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
Thomas Grafbfa83a92005-11-10 02:25:51 +0100536
537 return skb->len;
538}
539
540/**
Thomas Graffe4944e2006-08-04 23:03:05 -0700541 * nlmsg_get_pos - return current position in netlink message
542 * @skb: socket buffer the message is stored in
543 *
544 * Returns a pointer to the current tail of the message.
545 */
546static inline void *nlmsg_get_pos(struct sk_buff *skb)
547{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700548 return skb_tail_pointer(skb);
Thomas Graffe4944e2006-08-04 23:03:05 -0700549}
550
551/**
552 * nlmsg_trim - Trim message to a mark
553 * @skb: socket buffer the message is stored in
554 * @mark: mark to trim to
555 *
Thomas Grafbc3ed282008-06-03 16:36:54 -0700556 * Trims the message to the provided mark.
Thomas Graffe4944e2006-08-04 23:03:05 -0700557 */
Thomas Grafbc3ed282008-06-03 16:36:54 -0700558static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
Thomas Graffe4944e2006-08-04 23:03:05 -0700559{
560 if (mark)
561 skb_trim(skb, (unsigned char *) mark - skb->data);
Thomas Graffe4944e2006-08-04 23:03:05 -0700562}
563
564/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100565 * nlmsg_cancel - Cancel construction of a netlink message
566 * @skb: socket buffer the message is stored in
567 * @nlh: netlink message header
568 *
569 * Removes the complete netlink message including all
Thomas Grafbc3ed282008-06-03 16:36:54 -0700570 * attributes from the socket buffer again.
Thomas Grafbfa83a92005-11-10 02:25:51 +0100571 */
Thomas Grafbc3ed282008-06-03 16:36:54 -0700572static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100573{
Thomas Grafbc3ed282008-06-03 16:36:54 -0700574 nlmsg_trim(skb, nlh);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100575}
576
577/**
578 * nlmsg_free - free a netlink message
579 * @skb: socket buffer of netlink message
580 */
581static inline void nlmsg_free(struct sk_buff *skb)
582{
583 kfree_skb(skb);
584}
585
586/**
587 * nlmsg_multicast - multicast a netlink message
588 * @sk: netlink socket to spread messages to
589 * @skb: netlink message as socket buffer
590 * @pid: own netlink pid to avoid sending to yourself
591 * @group: multicast group id
Thomas Grafd387f6a2006-08-15 00:31:06 -0700592 * @flags: allocation flags
Thomas Grafbfa83a92005-11-10 02:25:51 +0100593 */
594static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
Thomas Grafd387f6a2006-08-15 00:31:06 -0700595 u32 pid, unsigned int group, gfp_t flags)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100596{
597 int err;
598
599 NETLINK_CB(skb).dst_group = group;
600
Thomas Grafd387f6a2006-08-15 00:31:06 -0700601 err = netlink_broadcast(sk, skb, pid, group, flags);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100602 if (err > 0)
603 err = 0;
604
605 return err;
606}
607
608/**
609 * nlmsg_unicast - unicast a netlink message
610 * @sk: netlink socket to spread message to
611 * @skb: netlink message as socket buffer
612 * @pid: netlink pid of the destination socket
613 */
614static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid)
615{
616 int err;
617
618 err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT);
619 if (err > 0)
620 err = 0;
621
622 return err;
623}
624
625/**
626 * nlmsg_for_each_msg - iterate over a stream of messages
627 * @pos: loop counter, set to current message
628 * @head: head of message stream
629 * @len: length of message stream
630 * @rem: initialized to len, holds bytes currently remaining in stream
631 */
632#define nlmsg_for_each_msg(pos, head, len, rem) \
633 for (pos = head, rem = len; \
634 nlmsg_ok(pos, rem); \
635 pos = nlmsg_next(pos, &(rem)))
636
637/**************************************************************************
638 * Netlink Attributes
639 **************************************************************************/
640
641/**
642 * nla_attr_size - length of attribute not including padding
643 * @payload: length of payload
644 */
645static inline int nla_attr_size(int payload)
646{
647 return NLA_HDRLEN + payload;
648}
649
650/**
651 * nla_total_size - total length of attribute including padding
652 * @payload: length of payload
653 */
654static inline int nla_total_size(int payload)
655{
656 return NLA_ALIGN(nla_attr_size(payload));
657}
658
659/**
660 * nla_padlen - length of padding at the tail of attribute
661 * @payload: length of payload
662 */
663static inline int nla_padlen(int payload)
664{
665 return nla_total_size(payload) - nla_attr_size(payload);
666}
667
668/**
Thomas Graf8f4c1f92007-09-12 14:44:36 +0200669 * nla_type - attribute type
670 * @nla: netlink attribute
671 */
672static inline int nla_type(const struct nlattr *nla)
673{
674 return nla->nla_type & NLA_TYPE_MASK;
675}
676
677/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100678 * nla_data - head of payload
679 * @nla: netlink attribute
680 */
681static inline void *nla_data(const struct nlattr *nla)
682{
683 return (char *) nla + NLA_HDRLEN;
684}
685
686/**
687 * nla_len - length of payload
688 * @nla: netlink attribute
689 */
690static inline int nla_len(const struct nlattr *nla)
691{
692 return nla->nla_len - NLA_HDRLEN;
693}
694
695/**
696 * nla_ok - check if the netlink attribute fits into the remaining bytes
697 * @nla: netlink attribute
698 * @remaining: number of bytes remaining in attribute stream
699 */
700static inline int nla_ok(const struct nlattr *nla, int remaining)
701{
Vegard Nossum1045b032008-09-11 19:05:29 -0700702 return remaining >= (int) sizeof(*nla) &&
Thomas Grafbfa83a92005-11-10 02:25:51 +0100703 nla->nla_len >= sizeof(*nla) &&
704 nla->nla_len <= remaining;
705}
706
707/**
Pierre Ynardd1ec3b72007-10-10 21:09:48 -0700708 * nla_next - next netlink attribute in attribute stream
Thomas Grafbfa83a92005-11-10 02:25:51 +0100709 * @nla: netlink attribute
710 * @remaining: number of bytes remaining in attribute stream
711 *
712 * Returns the next netlink attribute in the attribute stream and
713 * decrements remaining by the size of the current attribute.
714 */
715static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
716{
717 int totlen = NLA_ALIGN(nla->nla_len);
718
719 *remaining -= totlen;
720 return (struct nlattr *) ((char *) nla + totlen);
721}
722
723/**
Thomas Graffe4944e2006-08-04 23:03:05 -0700724 * nla_find_nested - find attribute in a set of nested attributes
725 * @nla: attribute containing the nested attributes
726 * @attrtype: type of attribute to look for
727 *
728 * Returns the first attribute which matches the specified type.
729 */
730static inline struct nlattr *nla_find_nested(struct nlattr *nla, int attrtype)
731{
732 return nla_find(nla_data(nla), nla_len(nla), attrtype);
733}
734
735/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100736 * nla_parse_nested - parse nested attributes
737 * @tb: destination array with maxtype+1 elements
738 * @maxtype: maximum attribute type to be expected
739 * @nla: attribute containing the nested attributes
740 * @policy: validation policy
741 *
742 * See nla_parse()
743 */
744static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
Patrick McHardyb057efd2008-10-28 11:59:11 -0700745 const struct nlattr *nla,
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700746 const struct nla_policy *policy)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100747{
748 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
749}
Patrick McHardy1092cb22007-06-25 13:49:35 -0700750
751/**
Pierre Ynardd1ec3b72007-10-10 21:09:48 -0700752 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
Thomas Grafbfa83a92005-11-10 02:25:51 +0100753 * @skb: socket buffer to add attribute to
754 * @attrtype: attribute type
755 * @value: numeric value
756 */
757static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
758{
759 return nla_put(skb, attrtype, sizeof(u8), &value);
760}
761
762/**
763 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
764 * @skb: socket buffer to add attribute to
765 * @attrtype: attribute type
766 * @value: numeric value
767 */
768static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
769{
770 return nla_put(skb, attrtype, sizeof(u16), &value);
771}
772
773/**
774 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
775 * @skb: socket buffer to add attribute to
776 * @attrtype: attribute type
777 * @value: numeric value
778 */
779static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
780{
781 return nla_put(skb, attrtype, sizeof(u32), &value);
782}
783
784/**
785 * nla_put_64 - Add a u64 netlink attribute to a socket buffer
786 * @skb: socket buffer to add attribute to
787 * @attrtype: attribute type
788 * @value: numeric value
789 */
790static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
791{
792 return nla_put(skb, attrtype, sizeof(u64), &value);
793}
794
795/**
796 * nla_put_string - Add a string netlink attribute to a socket buffer
797 * @skb: socket buffer to add attribute to
798 * @attrtype: attribute type
799 * @str: NUL terminated string
800 */
801static inline int nla_put_string(struct sk_buff *skb, int attrtype,
802 const char *str)
803{
804 return nla_put(skb, attrtype, strlen(str) + 1, str);
805}
806
807/**
808 * nla_put_flag - Add a flag netlink attribute to a socket buffer
809 * @skb: socket buffer to add attribute to
810 * @attrtype: attribute type
811 */
812static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
813{
814 return nla_put(skb, attrtype, 0, NULL);
815}
816
817/**
818 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer
819 * @skb: socket buffer to add attribute to
820 * @attrtype: attribute type
821 * @jiffies: number of msecs in jiffies
822 */
823static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
824 unsigned long jiffies)
825{
826 u64 tmp = jiffies_to_msecs(jiffies);
827 return nla_put(skb, attrtype, sizeof(u64), &tmp);
828}
829
830#define NLA_PUT(skb, attrtype, attrlen, data) \
831 do { \
Patrick McHardyf4d900a2007-12-05 03:31:53 -0800832 if (unlikely(nla_put(skb, attrtype, attrlen, data) < 0)) \
Thomas Grafbfa83a92005-11-10 02:25:51 +0100833 goto nla_put_failure; \
834 } while(0)
835
836#define NLA_PUT_TYPE(skb, type, attrtype, value) \
837 do { \
838 type __tmp = value; \
839 NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \
840 } while(0)
841
842#define NLA_PUT_U8(skb, attrtype, value) \
843 NLA_PUT_TYPE(skb, u8, attrtype, value)
844
845#define NLA_PUT_U16(skb, attrtype, value) \
846 NLA_PUT_TYPE(skb, u16, attrtype, value)
847
Thomas Graf4a89c252006-11-24 17:14:51 -0800848#define NLA_PUT_LE16(skb, attrtype, value) \
849 NLA_PUT_TYPE(skb, __le16, attrtype, value)
850
Patrick McHardy838965b2007-12-17 22:29:26 -0800851#define NLA_PUT_BE16(skb, attrtype, value) \
852 NLA_PUT_TYPE(skb, __be16, attrtype, value)
853
Thomas Grafbfa83a92005-11-10 02:25:51 +0100854#define NLA_PUT_U32(skb, attrtype, value) \
855 NLA_PUT_TYPE(skb, u32, attrtype, value)
856
Al Viro00012e52006-09-26 22:14:41 -0700857#define NLA_PUT_BE32(skb, attrtype, value) \
858 NLA_PUT_TYPE(skb, __be32, attrtype, value)
859
Thomas Grafbfa83a92005-11-10 02:25:51 +0100860#define NLA_PUT_U64(skb, attrtype, value) \
861 NLA_PUT_TYPE(skb, u64, attrtype, value)
862
Krzysztof Piotr Oledzki07a7c102008-07-21 10:01:14 -0700863#define NLA_PUT_BE64(skb, attrtype, value) \
864 NLA_PUT_TYPE(skb, __be64, attrtype, value)
865
Thomas Grafbfa83a92005-11-10 02:25:51 +0100866#define NLA_PUT_STRING(skb, attrtype, value) \
867 NLA_PUT(skb, attrtype, strlen(value) + 1, value)
868
Johannes Bergff5dfe72006-08-26 19:17:53 -0700869#define NLA_PUT_FLAG(skb, attrtype) \
Thomas Grafbfa83a92005-11-10 02:25:51 +0100870 NLA_PUT(skb, attrtype, 0, NULL)
871
872#define NLA_PUT_MSECS(skb, attrtype, jiffies) \
873 NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies))
874
875/**
876 * nla_get_u32 - return payload of u32 attribute
877 * @nla: u32 netlink attribute
878 */
Patrick McHardyb057efd2008-10-28 11:59:11 -0700879static inline u32 nla_get_u32(const struct nlattr *nla)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100880{
881 return *(u32 *) nla_data(nla);
882}
883
884/**
Al Viro00012e52006-09-26 22:14:41 -0700885 * nla_get_be32 - return payload of __be32 attribute
886 * @nla: __be32 netlink attribute
887 */
Patrick McHardyb057efd2008-10-28 11:59:11 -0700888static inline __be32 nla_get_be32(const struct nlattr *nla)
Al Viro00012e52006-09-26 22:14:41 -0700889{
890 return *(__be32 *) nla_data(nla);
891}
892
893/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100894 * nla_get_u16 - return payload of u16 attribute
895 * @nla: u16 netlink attribute
896 */
Patrick McHardyb057efd2008-10-28 11:59:11 -0700897static inline u16 nla_get_u16(const struct nlattr *nla)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100898{
899 return *(u16 *) nla_data(nla);
900}
901
902/**
Patrick McHardy838965b2007-12-17 22:29:26 -0800903 * nla_get_be16 - return payload of __be16 attribute
904 * @nla: __be16 netlink attribute
905 */
Patrick McHardyb057efd2008-10-28 11:59:11 -0700906static inline __be16 nla_get_be16(const struct nlattr *nla)
Patrick McHardy838965b2007-12-17 22:29:26 -0800907{
908 return *(__be16 *) nla_data(nla);
909}
910
911/**
Thomas Graf4a89c252006-11-24 17:14:51 -0800912 * nla_get_le16 - return payload of __le16 attribute
913 * @nla: __le16 netlink attribute
914 */
Patrick McHardyb057efd2008-10-28 11:59:11 -0700915static inline __le16 nla_get_le16(const struct nlattr *nla)
Thomas Graf4a89c252006-11-24 17:14:51 -0800916{
917 return *(__le16 *) nla_data(nla);
918}
919
920/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100921 * nla_get_u8 - return payload of u8 attribute
922 * @nla: u8 netlink attribute
923 */
Patrick McHardyb057efd2008-10-28 11:59:11 -0700924static inline u8 nla_get_u8(const struct nlattr *nla)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100925{
926 return *(u8 *) nla_data(nla);
927}
928
929/**
930 * nla_get_u64 - return payload of u64 attribute
931 * @nla: u64 netlink attribute
932 */
Patrick McHardyb057efd2008-10-28 11:59:11 -0700933static inline u64 nla_get_u64(const struct nlattr *nla)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100934{
935 u64 tmp;
936
937 nla_memcpy(&tmp, nla, sizeof(tmp));
938
939 return tmp;
940}
941
942/**
Pablo Neira Ayusoa17c8592009-05-27 17:50:35 +0200943 * nla_get_be64 - return payload of __be64 attribute
944 * @nla: __be64 netlink attribute
945 */
946static inline __be64 nla_get_be64(const struct nlattr *nla)
947{
Pablo Neira Ayusof5d410f2010-03-16 13:30:44 +0000948 __be64 tmp;
949
950 nla_memcpy(&tmp, nla, sizeof(tmp));
951
952 return tmp;
Pablo Neira Ayusoa17c8592009-05-27 17:50:35 +0200953}
954
955/**
Thomas Grafbfa83a92005-11-10 02:25:51 +0100956 * nla_get_flag - return payload of flag attribute
957 * @nla: flag netlink attribute
958 */
Patrick McHardyb057efd2008-10-28 11:59:11 -0700959static inline int nla_get_flag(const struct nlattr *nla)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100960{
961 return !!nla;
962}
963
964/**
965 * nla_get_msecs - return payload of msecs attribute
966 * @nla: msecs netlink attribute
967 *
968 * Returns the number of milliseconds in jiffies.
969 */
Patrick McHardyb057efd2008-10-28 11:59:11 -0700970static inline unsigned long nla_get_msecs(const struct nlattr *nla)
Thomas Grafbfa83a92005-11-10 02:25:51 +0100971{
972 u64 msecs = nla_get_u64(nla);
973
974 return msecs_to_jiffies((unsigned long) msecs);
975}
976
977/**
978 * nla_nest_start - Start a new level of nested attributes
979 * @skb: socket buffer to add attributes to
980 * @attrtype: attribute type of container
981 *
982 * Returns the container attribute
983 */
984static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
985{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700986 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
Thomas Grafbfa83a92005-11-10 02:25:51 +0100987
988 if (nla_put(skb, attrtype, 0, NULL) < 0)
989 return NULL;
990
991 return start;
992}
993
994/**
995 * nla_nest_end - Finalize nesting of attributes
Pierre Ynardd1ec3b72007-10-10 21:09:48 -0700996 * @skb: socket buffer the attributes are stored in
Thomas Grafbfa83a92005-11-10 02:25:51 +0100997 * @start: container attribute
998 *
999 * Corrects the container attribute header to include the all
1000 * appeneded attributes.
1001 *
1002 * Returns the total data length of the skb.
1003 */
1004static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1005{
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001006 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
Thomas Grafbfa83a92005-11-10 02:25:51 +01001007 return skb->len;
1008}
1009
1010/**
1011 * nla_nest_cancel - Cancel nesting of attributes
1012 * @skb: socket buffer the message is stored in
1013 * @start: container attribute
1014 *
1015 * Removes the container attribute and including all nested
Thomas Grafbc3ed282008-06-03 16:36:54 -07001016 * attributes. Returns -EMSGSIZE
Thomas Grafbfa83a92005-11-10 02:25:51 +01001017 */
Thomas Grafbc3ed282008-06-03 16:36:54 -07001018static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
Thomas Grafbfa83a92005-11-10 02:25:51 +01001019{
Thomas Grafbc3ed282008-06-03 16:36:54 -07001020 nlmsg_trim(skb, start);
Thomas Grafbfa83a92005-11-10 02:25:51 +01001021}
1022
1023/**
Paul Moore4fe5d5c2006-09-25 15:54:03 -07001024 * nla_validate_nested - Validate a stream of nested attributes
1025 * @start: container attribute
1026 * @maxtype: maximum attribute type to be expected
1027 * @policy: validation policy
1028 *
1029 * Validates all attributes in the nested attribute stream against the
1030 * specified policy. Attributes with a type exceeding maxtype will be
1031 * ignored. See documenation of struct nla_policy for more details.
1032 *
1033 * Returns 0 on success or a negative error code.
1034 */
1035static inline int nla_validate_nested(struct nlattr *start, int maxtype,
Patrick McHardyef7c79e2007-06-05 12:38:30 -07001036 const struct nla_policy *policy)
Paul Moore4fe5d5c2006-09-25 15:54:03 -07001037{
1038 return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
1039}
1040
1041/**
Thomas Grafbfa83a92005-11-10 02:25:51 +01001042 * nla_for_each_attr - iterate over a stream of attributes
1043 * @pos: loop counter, set to current attribute
1044 * @head: head of attribute stream
1045 * @len: length of attribute stream
1046 * @rem: initialized to len, holds bytes currently remaining in stream
1047 */
1048#define nla_for_each_attr(pos, head, len, rem) \
1049 for (pos = head, rem = len; \
1050 nla_ok(pos, rem); \
1051 pos = nla_next(pos, &(rem)))
1052
Thomas Graffe4944e2006-08-04 23:03:05 -07001053/**
1054 * nla_for_each_nested - iterate over nested attributes
1055 * @pos: loop counter, set to current attribute
1056 * @nla: attribute containing the nested attributes
1057 * @rem: initialized to len, holds bytes currently remaining in stream
1058 */
1059#define nla_for_each_nested(pos, nla, rem) \
1060 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1061
Thomas Grafbfa83a92005-11-10 02:25:51 +01001062#endif