summaryrefslogtreecommitdiffstats
path: root/package/libs/libnl-tiny/src/include/netlink/attr.h
blob: 3b56a82dc66e21376a6466f16ca37ff57569d969 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
/*
 * netlink/attr.h		Netlink Attributes
 *
 *	This library is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU Lesser General Public
 *	License as published by the Free Software Foundation version 2.1
 *	of the License.
 *
 * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
 */

#ifndef NETLINK_ATTR_H_
#define NETLINK_ATTR_H_

#include <netlink/netlink.h>
#include <netlink/object.h>
#include <netlink/addr.h>
#include <netlink/data.h>
#include <netlink/msg.h>

#ifdef __cplusplus
extern "C" {
#endif

struct nl_msg;

/**
 * @name Basic Attribute Data Types
 * @{
 */

 /**
  * @ingroup attr
  * Basic attribute data types
  *
  * See \ref attr_datatypes for more details.
  */
enum {
	NLA_UNSPEC,	/**< Unspecified type, binary data chunk */
	NLA_U8,		/**< 8 bit integer */
	NLA_U16,	/**< 16 bit integer */
	NLA_U32,	/**< 32 bit integer */
	NLA_U64,	/**< 64 bit integer */
	NLA_STRING,	/**< NUL terminated character string */
	NLA_FLAG,	/**< Flag */
	NLA_MSECS,	/**< Micro seconds (64bit) */
	NLA_NESTED,	/**< Nested attributes */
	__NLA_TYPE_MAX,
};

#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)

/** @} */

/**
 * @ingroup attr
 * Attribute validation policy.
 *
 * See \ref attr_datatypes for more details.
 */
struct nla_policy {
	/** Type of attribute or NLA_UNSPEC */
	uint16_t	type;

	/** Minimal length of payload required */
	uint16_t	minlen;

	/** Maximal length of payload allowed */
	uint16_t	maxlen;
};

/* Attribute parsing */
extern int		nla_ok(const struct nlattr *, int);
extern struct nlattr *	nla_next(const struct nlattr *, int *);
extern int		nla_parse(struct nlattr **, int, struct nlattr *,
				  int, struct nla_policy *);
extern int		nla_validate(struct nlattr *, int, int,
				     struct nla_policy *);
extern struct nlattr *	nla_find(struct nlattr *, int, int);

/* Unspecific attribute */
extern struct nlattr *	nla_reserve(struct nl_msg *, int, int);
extern int		nla_put(struct nl_msg *, int, int, const void *);

/**
 * nlmsg_find_attr - find a specific attribute in a netlink message
 * @arg nlh		netlink message header
 * @arg hdrlen		length of familiy specific header
 * @arg attrtype	type of attribute to look for
 *
 * Returns the first attribute which matches the specified type.
 */
static inline struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh, int hdrlen, int attrtype)
{
	return nla_find(nlmsg_attrdata(nlh, hdrlen),
			nlmsg_attrlen(nlh, hdrlen), attrtype);
}


/**
 * Return size of attribute whithout padding.
 * @arg payload		Payload length of attribute.
 *
 * @code
 *    <-------- nla_attr_size(payload) --------->
 *   +------------------+- - -+- - - - - - - - - +- - -+
 *   | Attribute Header | Pad |     Payload      | Pad |
 *   +------------------+- - -+- - - - - - - - - +- - -+
 * @endcode
 *
 * @return Size of attribute in bytes without padding.
 */
static inline int nla_attr_size(int payload)
{
	return NLA_HDRLEN + payload;
}

/**
 * Return size of attribute including padding.
 * @arg payload		Payload length of attribute.
 *
 * @code
 *    <----------- nla_total_size(payload) ----------->
 *   +------------------+- - -+- - - - - - - - - +- - -+
 *   | Attribute Header | Pad |     Payload      | Pad |
 *   +------------------+- - -+- - - - - - - - - +- - -+
 * @endcode
 *
 * @return Size of attribute in bytes.
 */
static inline int nla_total_size(int payload)
{
	return NLA_ALIGN(nla_attr_size(payload));
}

/**
 * Return length of padding at the tail of the attribute.
 * @arg payload		Payload length of attribute.
 *
 * @code
 *   +------------------+- - -+- - - - - - - - - +- - -+
 *   | Attribute Header | Pad |     Payload      | Pad |
 *   +------------------+- - -+- - - - - - - - - +- - -+
 *                                                <--->  
 * @endcode
 *
 * @return Length of padding in bytes.
 */
static inline int nla_padlen(int payload)
{
	return nla_total_size(payload) - nla_attr_size(payload);
}

/**
 * Return type of the attribute.
 * @arg nla		Attribute.
 *
 * @return Type of attribute.
 */
static inline int nla_type(const struct nlattr *nla)
{
	return nla->nla_type & NLA_TYPE_MASK;
}

/**
 * Return pointer to the payload section.
 * @arg nla		Attribute.
 *
 * @return Pointer to start of payload section.
 */
static inline void *nla_data(const struct nlattr *nla)
{
	return (char *) nla + NLA_HDRLEN;
}

/**
 * Return length of the payload .
 * @arg nla		Attribute
 *
 * @return Length of payload in bytes.
 */
static inline int nla_len(const struct nlattr *nla)
{
	return nla->nla_len - NLA_HDRLEN;
}

/**
 * Copy attribute payload to another memory area.
 * @arg dest		Pointer to destination memory area.
 * @arg src		Attribute
 * @arg count		Number of bytes to copy at most.
 *
 * Note: The number of bytes copied is limited by the length of
 *       the attribute payload.
 *
 * @return The number of bytes copied to dest.
 */
static inline int nla_memcpy(void *dest, struct nlattr *src, int count)
{
	int minlen;

	if (!src)
		return 0;
	
	minlen = min_t(int, count, nla_len(src));
	memcpy(dest, nla_data(src), minlen);

	return minlen;
}


/**
 * Add abstract data as unspecific attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg data		Abstract data object.
 *
 * Equivalent to nla_put() except that the length of the payload is
 * derived from the abstract data object.
 *
 * @see nla_put
 * @return 0 on success or a negative error code.
 */
static inline int nla_put_data(struct nl_msg *msg, int attrtype, struct nl_data *data)
{
	return nla_put(msg, attrtype, nl_data_get_size(data),
		       nl_data_get(data));
}

/**
 * Add abstract address as unspecific attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg addr		Abstract address object.
 *
 * @see nla_put
 * @return 0 on success or a negative error code.
 */
static inline int nla_put_addr(struct nl_msg *msg, int attrtype, struct nl_addr *addr)
{
	return nla_put(msg, attrtype, nl_addr_get_len(addr),
		       nl_addr_get_binary_addr(addr));
}

/** @} */

/**
 * @name Integer Attributes
 */

/**
 * Add 8 bit integer attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg value		Numeric value to store as payload.
 *
 * @see nla_put
 * @return 0 on success or a negative error code.
 */
static inline int nla_put_u8(struct nl_msg *msg, int attrtype, uint8_t value)
{
	return nla_put(msg, attrtype, sizeof(uint8_t), &value);
}

/**
 * Return value of 8 bit integer attribute.
 * @arg nla		8 bit integer attribute
 *
 * @return Payload as 8 bit integer.
 */
static inline uint8_t nla_get_u8(struct nlattr *nla)
{
	return *(uint8_t *) nla_data(nla);
}

/**
 * Add 16 bit integer attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg value		Numeric value to store as payload.
 *
 * @see nla_put
 * @return 0 on success or a negative error code.
 */
static inline int nla_put_u16(struct nl_msg *msg, int attrtype, uint16_t value)
{
	return nla_put(msg, attrtype, sizeof(uint16_t), &value);
}

/**
 * Return payload of 16 bit integer attribute.
 * @arg nla		16 bit integer attribute
 *
 * @return Payload as 16 bit integer.
 */
static inline uint16_t nla_get_u16(struct nlattr *nla)
{
	return *(uint16_t *) nla_data(nla);
}

/**
 * Add 32 bit integer attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg value		Numeric value to store as payload.
 *
 * @see nla_put
 * @return 0 on success or a negative error code.
 */
static inline int nla_put_u32(struct nl_msg *msg, int attrtype, uint32_t value)
{
	return nla_put(msg, attrtype, sizeof(uint32_t), &value);
}

/**
 * Return payload of 32 bit integer attribute.
 * @arg nla		32 bit integer attribute.
 *
 * @return Payload as 32 bit integer.
 */
static inline uint32_t nla_get_u32(struct nlattr *nla)
{
	return *(uint32_t *) nla_data(nla);
}

/**
 * Add 64 bit integer attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg value		Numeric value to store as payload.
 *
 * @see nla_put
 * @return 0 on success or a negative error code.
 */
static inline int nla_put_u64(struct nl_msg *msg, int attrtype, uint64_t value)
{
	return nla_put(msg, attrtype, sizeof(uint64_t), &value);
}

/**
 * Return payload of u64 attribute
 * @arg nla		u64 netlink attribute
 *
 * @return Payload as 64 bit integer.
 */
static inline uint64_t nla_get_u64(struct nlattr *nla)
{
	uint64_t tmp;

	nla_memcpy(&tmp, nla, sizeof(tmp));

	return tmp;
}

/**
 * Add string attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg str		NUL terminated string.
 *
 * @see nla_put
 * @return 0 on success or a negative error code.
 */
static inline int nla_put_string(struct nl_msg *msg, int attrtype, const char *str)
{
	return nla_put(msg, attrtype, strlen(str) + 1, str);
}

/**
 * Return payload of string attribute.
 * @arg nla		String attribute.
 *
 * @return Pointer to attribute payload.
 */
static inline char *nla_get_string(struct nlattr *nla)
{
	return (char *) nla_data(nla);
}

static inline char *nla_strdup(struct nlattr *nla)
{
	return strdup(nla_get_string(nla));
}

/** @} */

/**
 * @name Flag Attribute
 */

/**
 * Add flag netlink attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 *
 * @see nla_put
 * @return 0 on success or a negative error code.
 */
static inline int nla_put_flag(struct nl_msg *msg, int attrtype)
{
	return nla_put(msg, attrtype, 0, NULL);
}

/**
 * Return true if flag attribute is set.
 * @arg nla		Flag netlink attribute.
 *
 * @return True if flag is set, otherwise false.
 */
static inline int nla_get_flag(struct nlattr *nla)
{
	return !!nla;
}

/** @} */

/**
 * @name Microseconds Attribute
 */

/**
 * Add a msecs netlink attribute to a netlink message
 * @arg n		netlink message
 * @arg attrtype	attribute type
 * @arg msecs 		number of msecs
 */
static inline int nla_put_msecs(struct nl_msg *n, int attrtype, unsigned long msecs)
{
	return nla_put_u64(n, attrtype, msecs);
}

/**
 * Return payload of msecs attribute
 * @arg nla		msecs netlink attribute
 *
 * @return the number of milliseconds.
 */
static inline unsigned long nla_get_msecs(struct nlattr *nla)
{
	return nla_get_u64(nla);
}

/**
 * Add nested attributes to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg nested		Message containing attributes to be nested.
 *
 * Takes the attributes found in the \a nested message and appends them
 * to the message \a msg nested in a container of the type \a attrtype.
 * The \a nested message may not have a family specific header.
 *
 * @see nla_put
 * @return 0 on success or a negative error code.
 */
static inline int nla_put_nested(struct nl_msg *msg, int attrtype, struct nl_msg *nested)
{
	return nla_put(msg, attrtype, nlmsg_len(nested->nm_nlh),
		       nlmsg_data(nested->nm_nlh));
}

/**
 * Start a new level of nested attributes.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type of container.
 *
 * @return Pointer to container attribute.
 */
static inline struct nlattr *nla_nest_start(struct nl_msg *msg, int attrtype)
{
	struct nlattr *start = (struct nlattr *) nlmsg_tail(msg->nm_nlh);

	if (nla_put(msg, attrtype, 0, NULL) < 0)
		return NULL;

	return start;
}

/**
 * Finalize nesting of attributes.
 * @arg msg		Netlink message.
 * @arg start		Container attribute as returned from nla_nest_start().
 *
 * Corrects the container attribute header to include the appeneded attributes.
 *
 * @return 0
 */
static inline int nla_nest_end(struct nl_msg *msg, struct nlattr *start)
{
	start->nla_len = (unsigned char *) nlmsg_tail(msg->nm_nlh) -
				(unsigned char *) start;
	return 0;
}

/**
 * Create attribute index based on nested attribute
 * @arg tb		Index array to be filled (maxtype+1 elements).
 * @arg maxtype		Maximum attribute type expected and accepted.
 * @arg nla		Nested Attribute.
 * @arg policy		Attribute validation policy.
 *
 * Feeds the stream of attributes nested into the specified attribute
 * to nla_parse().
 *
 * @see nla_parse
 * @return 0 on success or a negative error code.
 */
static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, struct nlattr *nla,
		     struct nla_policy *policy)
{
	return nla_parse(tb, maxtype, (struct nlattr *)nla_data(nla), nla_len(nla), policy);
}

/**
 * Compare attribute payload with memory area.
 * @arg nla		Attribute.
 * @arg data		Memory area to compare to.
 * @arg size		Number of bytes to compare.
 *
 * @see memcmp(3)
 * @return An integer less than, equal to, or greater than zero.
 */
static inline int nla_memcmp(const struct nlattr *nla, const void *data, size_t size)
{
	int d = nla_len(nla) - size;

	if (d == 0)
		d = memcmp(nla_data(nla), data, size);

	return d;
}

/**
 * Compare string attribute payload with string
 * @arg nla		Attribute of type NLA_STRING.
 * @arg str		NUL terminated string.
 *
 * @see strcmp(3)
 * @return An integer less than, equal to, or greater than zero.
 */
static inline int nla_strcmp(const struct nlattr *nla, const char *str)
{
	int len = strlen(str) + 1;
	int d = nla_len(nla) - len;

	if (d == 0)
		d = memcmp(nla_data(nla), str, len);

	return d;
}

/**
 * Copy string attribute payload to a buffer.
 * @arg dst		Pointer to destination buffer.
 * @arg nla		Attribute of type NLA_STRING.
 * @arg dstsize		Size of destination buffer in bytes.
 *
 * Copies at most dstsize - 1 bytes to the destination buffer.
 * The result is always a valid NUL terminated string. Unlike
 * strlcpy the destination buffer is always padded out.
 *
 * @return The length of string attribute without the terminating NUL.
 */
static inline size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize)
{
	size_t srclen = (size_t)nla_len(nla);
	char *src = (char*)nla_data(nla);

	if (srclen > 0 && src[srclen - 1] == '\0')
		srclen--;

	if (dstsize > 0) {
		size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen;

		memset(dst, 0, dstsize);
		memcpy(dst, src, len);
	}

	return srclen;
}


/**
 * @name Attribute Construction (Exception Based)
 * @{
 */

/**
 * @ingroup attr
 * Add unspecific attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg attrlen		Length of attribute payload.
 * @arg data		Head of attribute payload.
 */
#define NLA_PUT(msg, attrtype, attrlen, data) \
	do { \
		if (nla_put(msg, attrtype, attrlen, data) < 0) \
			goto nla_put_failure; \
	} while(0)

/**
 * @ingroup attr
 * Add atomic type attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg type		Atomic type.
 * @arg attrtype	Attribute type.
 * @arg value		Head of attribute payload.
 */
#define NLA_PUT_TYPE(msg, type, attrtype, value) \
	do { \
		type __tmp = value; \
		NLA_PUT(msg, attrtype, sizeof(type), &__tmp); \
	} while(0)

/**
 * Add 8 bit integer attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg value		Numeric value.
 */
#define NLA_PUT_U8(msg, attrtype, value) \
	NLA_PUT_TYPE(msg, uint8_t, attrtype, value)

/**
 * Add 16 bit integer attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg value		Numeric value.
 */
#define NLA_PUT_U16(msg, attrtype, value) \
	NLA_PUT_TYPE(msg, uint16_t, attrtype, value)

/**
 * Add 32 bit integer attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg value		Numeric value.
 */
#define NLA_PUT_U32(msg, attrtype, value) \
	NLA_PUT_TYPE(msg, uint32_t, attrtype, value)

/**
 * Add 64 bit integer attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg value		Numeric value.
 */
#define NLA_PUT_U64(msg, attrtype, value) \
	NLA_PUT_TYPE(msg, uint64_t, attrtype, value)

/**
 * Add string attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg value		NUL terminated character string.
 */
#define NLA_PUT_STRING(msg, attrtype, value) \
	NLA_PUT(msg, attrtype, strlen(value) + 1, value)

/**
 * Add flag attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 */
#define NLA_PUT_FLAG(msg, attrtype) \
	NLA_PUT(msg, attrtype, 0, NULL)

/**
 * Add msecs attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg msecs		Numeric value in micro seconds.
 */
#define NLA_PUT_MSECS(msg, attrtype, msecs) \
	NLA_PUT_U64(msg, attrtype, msecs)

/**
 * Add address attribute to netlink message.
 * @arg msg		Netlink message.
 * @arg attrtype	Attribute type.
 * @arg addr		Abstract address object.
 */
#define NLA_PUT_ADDR(msg, attrtype, addr) \
	NLA_PUT(msg, attrtype, nl_addr_get_len(addr), \
		nl_addr_get_binary_addr(addr))

/** @} */

/**
 * @name Iterators
 * @{
 */

/**
 * @ingroup attr
 * Iterate over a stream of attributes
 * @arg pos	loop counter, set to current attribute
 * @arg head	head of attribute stream
 * @arg len	length of attribute stream
 * @arg rem	initialized to len, holds bytes currently remaining in stream
 */
#define nla_for_each_attr(pos, head, len, rem) \
	for (pos = head, rem = len; \
	     nla_ok(pos, rem); \
	     pos = nla_next(pos, &(rem)))

/**
 * @ingroup attr
 * Iterate over a stream of nested attributes
 * @arg pos	loop counter, set to current attribute
 * @arg nla	attribute containing the nested attributes
 * @arg rem	initialized to len, holds bytes currently remaining in stream
 */
#define nla_for_each_nested(pos, nla, rem) \
	for (pos = (struct nlattr *)nla_data(nla), rem = nla_len(nla); \
	     nla_ok(pos, rem); \
	     pos = nla_next(pos, &(rem)))

/** @} */

#ifdef __cplusplus
}
#endif

#endif