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1 | /* | |
2 | * NETLINK Netlink attributes | |
3 | * | |
4 | * Authors: Thomas Graf <tgraf@suug.ch> | |
5 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> | |
6 | */ | |
7 | ||
8 | #include <linux/export.h> | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/errno.h> | |
11 | #include <linux/jiffies.h> | |
12 | #include <linux/skbuff.h> | |
13 | #include <linux/string.h> | |
14 | #include <linux/types.h> | |
15 | #include <net/netlink.h> | |
16 | ||
17 | static const u16 nla_attr_minlen[NLA_TYPE_MAX+1] = { | |
18 | [NLA_U8] = sizeof(u8), | |
19 | [NLA_U16] = sizeof(u16), | |
20 | [NLA_U32] = sizeof(u32), | |
21 | [NLA_U64] = sizeof(u64), | |
22 | [NLA_MSECS] = sizeof(u64), | |
23 | [NLA_NESTED] = NLA_HDRLEN, | |
24 | [NLA_S8] = sizeof(s8), | |
25 | [NLA_S16] = sizeof(s16), | |
26 | [NLA_S32] = sizeof(s32), | |
27 | [NLA_S64] = sizeof(s64), | |
28 | }; | |
29 | ||
30 | static int validate_nla(const struct nlattr *nla, int maxtype, | |
31 | const struct nla_policy *policy) | |
32 | { | |
33 | const struct nla_policy *pt; | |
34 | int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla); | |
35 | ||
36 | if (type <= 0 || type > maxtype) | |
37 | return 0; | |
38 | ||
39 | pt = &policy[type]; | |
40 | ||
41 | BUG_ON(pt->type > NLA_TYPE_MAX); | |
42 | ||
43 | switch (pt->type) { | |
44 | case NLA_FLAG: | |
45 | if (attrlen > 0) | |
46 | return -ERANGE; | |
47 | break; | |
48 | ||
49 | case NLA_NUL_STRING: | |
50 | if (pt->len) | |
51 | minlen = min_t(int, attrlen, pt->len + 1); | |
52 | else | |
53 | minlen = attrlen; | |
54 | ||
55 | if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) | |
56 | return -EINVAL; | |
57 | /* fall through */ | |
58 | ||
59 | case NLA_STRING: | |
60 | if (attrlen < 1) | |
61 | return -ERANGE; | |
62 | ||
63 | if (pt->len) { | |
64 | char *buf = nla_data(nla); | |
65 | ||
66 | if (buf[attrlen - 1] == '\0') | |
67 | attrlen--; | |
68 | ||
69 | if (attrlen > pt->len) | |
70 | return -ERANGE; | |
71 | } | |
72 | break; | |
73 | ||
74 | case NLA_BINARY: | |
75 | if (pt->len && attrlen > pt->len) | |
76 | return -ERANGE; | |
77 | break; | |
78 | ||
79 | case NLA_NESTED_COMPAT: | |
80 | if (attrlen < pt->len) | |
81 | return -ERANGE; | |
82 | if (attrlen < NLA_ALIGN(pt->len)) | |
83 | break; | |
84 | if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN) | |
85 | return -ERANGE; | |
86 | nla = nla_data(nla) + NLA_ALIGN(pt->len); | |
87 | if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN + nla_len(nla)) | |
88 | return -ERANGE; | |
89 | break; | |
90 | case NLA_NESTED: | |
91 | /* a nested attributes is allowed to be empty; if its not, | |
92 | * it must have a size of at least NLA_HDRLEN. | |
93 | */ | |
94 | if (attrlen == 0) | |
95 | break; | |
96 | default: | |
97 | if (pt->len) | |
98 | minlen = pt->len; | |
99 | else if (pt->type != NLA_UNSPEC) | |
100 | minlen = nla_attr_minlen[pt->type]; | |
101 | ||
102 | if (attrlen < minlen) | |
103 | return -ERANGE; | |
104 | } | |
105 | ||
106 | return 0; | |
107 | } | |
108 | ||
109 | /** | |
110 | * nla_validate - Validate a stream of attributes | |
111 | * @head: head of attribute stream | |
112 | * @len: length of attribute stream | |
113 | * @maxtype: maximum attribute type to be expected | |
114 | * @policy: validation policy | |
115 | * | |
116 | * Validates all attributes in the specified attribute stream against the | |
117 | * specified policy. Attributes with a type exceeding maxtype will be | |
118 | * ignored. See documenation of struct nla_policy for more details. | |
119 | * | |
120 | * Returns 0 on success or a negative error code. | |
121 | */ | |
122 | int nla_validate(const struct nlattr *head, int len, int maxtype, | |
123 | const struct nla_policy *policy) | |
124 | { | |
125 | const struct nlattr *nla; | |
126 | int rem, err; | |
127 | ||
128 | nla_for_each_attr(nla, head, len, rem) { | |
129 | err = validate_nla(nla, maxtype, policy); | |
130 | if (err < 0) | |
131 | goto errout; | |
132 | } | |
133 | ||
134 | err = 0; | |
135 | errout: | |
136 | return err; | |
137 | } | |
138 | EXPORT_SYMBOL(nla_validate); | |
139 | ||
140 | /** | |
141 | * nla_policy_len - Determin the max. length of a policy | |
142 | * @policy: policy to use | |
143 | * @n: number of policies | |
144 | * | |
145 | * Determines the max. length of the policy. It is currently used | |
146 | * to allocated Netlink buffers roughly the size of the actual | |
147 | * message. | |
148 | * | |
149 | * Returns 0 on success or a negative error code. | |
150 | */ | |
151 | int | |
152 | nla_policy_len(const struct nla_policy *p, int n) | |
153 | { | |
154 | int i, len = 0; | |
155 | ||
156 | for (i = 0; i < n; i++, p++) { | |
157 | if (p->len) | |
158 | len += nla_total_size(p->len); | |
159 | else if (nla_attr_minlen[p->type]) | |
160 | len += nla_total_size(nla_attr_minlen[p->type]); | |
161 | } | |
162 | ||
163 | return len; | |
164 | } | |
165 | EXPORT_SYMBOL(nla_policy_len); | |
166 | ||
167 | /** | |
168 | * nla_parse - Parse a stream of attributes into a tb buffer | |
169 | * @tb: destination array with maxtype+1 elements | |
170 | * @maxtype: maximum attribute type to be expected | |
171 | * @head: head of attribute stream | |
172 | * @len: length of attribute stream | |
173 | * @policy: validation policy | |
174 | * | |
175 | * Parses a stream of attributes and stores a pointer to each attribute in | |
176 | * the tb array accessible via the attribute type. Attributes with a type | |
177 | * exceeding maxtype will be silently ignored for backwards compatibility | |
178 | * reasons. policy may be set to NULL if no validation is required. | |
179 | * | |
180 | * Returns 0 on success or a negative error code. | |
181 | */ | |
182 | int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, | |
183 | int len, const struct nla_policy *policy) | |
184 | { | |
185 | const struct nlattr *nla; | |
186 | int rem, err; | |
187 | ||
188 | memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); | |
189 | ||
190 | nla_for_each_attr(nla, head, len, rem) { | |
191 | u16 type = nla_type(nla); | |
192 | ||
193 | if (type > 0 && type <= maxtype) { | |
194 | if (policy) { | |
195 | err = validate_nla(nla, maxtype, policy); | |
196 | if (err < 0) | |
197 | goto errout; | |
198 | } | |
199 | ||
200 | tb[type] = (struct nlattr *)nla; | |
201 | } | |
202 | } | |
203 | ||
204 | if (unlikely(rem > 0)) | |
205 | pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n", | |
206 | rem, current->comm); | |
207 | ||
208 | err = 0; | |
209 | errout: | |
210 | return err; | |
211 | } | |
212 | EXPORT_SYMBOL(nla_parse); | |
213 | ||
214 | /** | |
215 | * nla_find - Find a specific attribute in a stream of attributes | |
216 | * @head: head of attribute stream | |
217 | * @len: length of attribute stream | |
218 | * @attrtype: type of attribute to look for | |
219 | * | |
220 | * Returns the first attribute in the stream matching the specified type. | |
221 | */ | |
222 | struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype) | |
223 | { | |
224 | const struct nlattr *nla; | |
225 | int rem; | |
226 | ||
227 | nla_for_each_attr(nla, head, len, rem) | |
228 | if (nla_type(nla) == attrtype) | |
229 | return (struct nlattr *)nla; | |
230 | ||
231 | return NULL; | |
232 | } | |
233 | EXPORT_SYMBOL(nla_find); | |
234 | ||
235 | /** | |
236 | * nla_strlcpy - Copy string attribute payload into a sized buffer | |
237 | * @dst: where to copy the string to | |
238 | * @nla: attribute to copy the string from | |
239 | * @dstsize: size of destination buffer | |
240 | * | |
241 | * Copies at most dstsize - 1 bytes into the destination buffer. | |
242 | * The result is always a valid NUL-terminated string. Unlike | |
243 | * strlcpy the destination buffer is always padded out. | |
244 | * | |
245 | * Returns the length of the source buffer. | |
246 | */ | |
247 | size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize) | |
248 | { | |
249 | size_t srclen = nla_len(nla); | |
250 | char *src = nla_data(nla); | |
251 | ||
252 | if (srclen > 0 && src[srclen - 1] == '\0') | |
253 | srclen--; | |
254 | ||
255 | if (dstsize > 0) { | |
256 | size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen; | |
257 | ||
258 | memset(dst, 0, dstsize); | |
259 | memcpy(dst, src, len); | |
260 | } | |
261 | ||
262 | return srclen; | |
263 | } | |
264 | EXPORT_SYMBOL(nla_strlcpy); | |
265 | ||
266 | /** | |
267 | * nla_memcpy - Copy a netlink attribute into another memory area | |
268 | * @dest: where to copy to memcpy | |
269 | * @src: netlink attribute to copy from | |
270 | * @count: size of the destination area | |
271 | * | |
272 | * Note: The number of bytes copied is limited by the length of | |
273 | * attribute's payload. memcpy | |
274 | * | |
275 | * Returns the number of bytes copied. | |
276 | */ | |
277 | int nla_memcpy(void *dest, const struct nlattr *src, int count) | |
278 | { | |
279 | int minlen = min_t(int, count, nla_len(src)); | |
280 | ||
281 | memcpy(dest, nla_data(src), minlen); | |
282 | if (count > minlen) | |
283 | memset(dest + minlen, 0, count - minlen); | |
284 | ||
285 | return minlen; | |
286 | } | |
287 | EXPORT_SYMBOL(nla_memcpy); | |
288 | ||
289 | /** | |
290 | * nla_memcmp - Compare an attribute with sized memory area | |
291 | * @nla: netlink attribute | |
292 | * @data: memory area | |
293 | * @size: size of memory area | |
294 | */ | |
295 | int nla_memcmp(const struct nlattr *nla, const void *data, | |
296 | size_t size) | |
297 | { | |
298 | int d = nla_len(nla) - size; | |
299 | ||
300 | if (d == 0) | |
301 | d = memcmp(nla_data(nla), data, size); | |
302 | ||
303 | return d; | |
304 | } | |
305 | EXPORT_SYMBOL(nla_memcmp); | |
306 | ||
307 | /** | |
308 | * nla_strcmp - Compare a string attribute against a string | |
309 | * @nla: netlink string attribute | |
310 | * @str: another string | |
311 | */ | |
312 | int nla_strcmp(const struct nlattr *nla, const char *str) | |
313 | { | |
314 | int len = strlen(str); | |
315 | char *buf = nla_data(nla); | |
316 | int attrlen = nla_len(nla); | |
317 | int d; | |
318 | ||
319 | if (attrlen > 0 && buf[attrlen - 1] == '\0') | |
320 | attrlen--; | |
321 | ||
322 | d = attrlen - len; | |
323 | if (d == 0) | |
324 | d = memcmp(nla_data(nla), str, len); | |
325 | ||
326 | return d; | |
327 | } | |
328 | EXPORT_SYMBOL(nla_strcmp); | |
329 | ||
330 | #ifdef CONFIG_NET | |
331 | /** | |
332 | * __nla_reserve - reserve room for attribute on the skb | |
333 | * @skb: socket buffer to reserve room on | |
334 | * @attrtype: attribute type | |
335 | * @attrlen: length of attribute payload | |
336 | * | |
337 | * Adds a netlink attribute header to a socket buffer and reserves | |
338 | * room for the payload but does not copy it. | |
339 | * | |
340 | * The caller is responsible to ensure that the skb provides enough | |
341 | * tailroom for the attribute header and payload. | |
342 | */ | |
343 | struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) | |
344 | { | |
345 | struct nlattr *nla; | |
346 | ||
347 | nla = (struct nlattr *) skb_put(skb, nla_total_size(attrlen)); | |
348 | nla->nla_type = attrtype; | |
349 | nla->nla_len = nla_attr_size(attrlen); | |
350 | ||
351 | memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen)); | |
352 | ||
353 | return nla; | |
354 | } | |
355 | EXPORT_SYMBOL(__nla_reserve); | |
356 | ||
357 | /** | |
358 | * __nla_reserve_64bit - reserve room for attribute on the skb and align it | |
359 | * @skb: socket buffer to reserve room on | |
360 | * @attrtype: attribute type | |
361 | * @attrlen: length of attribute payload | |
362 | * @padattr: attribute type for the padding | |
363 | * | |
364 | * Adds a netlink attribute header to a socket buffer and reserves | |
365 | * room for the payload but does not copy it. It also ensure that this | |
366 | * attribute will have a 64-bit aligned nla_data() area. | |
367 | * | |
368 | * The caller is responsible to ensure that the skb provides enough | |
369 | * tailroom for the attribute header and payload. | |
370 | */ | |
371 | struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, | |
372 | int attrlen, int padattr) | |
373 | { | |
374 | if (nla_need_padding_for_64bit(skb)) | |
375 | nla_align_64bit(skb, padattr); | |
376 | ||
377 | return __nla_reserve(skb, attrtype, attrlen); | |
378 | } | |
379 | EXPORT_SYMBOL(__nla_reserve_64bit); | |
380 | ||
381 | /** | |
382 | * __nla_reserve_nohdr - reserve room for attribute without header | |
383 | * @skb: socket buffer to reserve room on | |
384 | * @attrlen: length of attribute payload | |
385 | * | |
386 | * Reserves room for attribute payload without a header. | |
387 | * | |
388 | * The caller is responsible to ensure that the skb provides enough | |
389 | * tailroom for the payload. | |
390 | */ | |
391 | void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen) | |
392 | { | |
393 | void *start; | |
394 | ||
395 | start = skb_put(skb, NLA_ALIGN(attrlen)); | |
396 | memset(start, 0, NLA_ALIGN(attrlen)); | |
397 | ||
398 | return start; | |
399 | } | |
400 | EXPORT_SYMBOL(__nla_reserve_nohdr); | |
401 | ||
402 | /** | |
403 | * nla_reserve - reserve room for attribute on the skb | |
404 | * @skb: socket buffer to reserve room on | |
405 | * @attrtype: attribute type | |
406 | * @attrlen: length of attribute payload | |
407 | * | |
408 | * Adds a netlink attribute header to a socket buffer and reserves | |
409 | * room for the payload but does not copy it. | |
410 | * | |
411 | * Returns NULL if the tailroom of the skb is insufficient to store | |
412 | * the attribute header and payload. | |
413 | */ | |
414 | struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) | |
415 | { | |
416 | if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen))) | |
417 | return NULL; | |
418 | ||
419 | return __nla_reserve(skb, attrtype, attrlen); | |
420 | } | |
421 | EXPORT_SYMBOL(nla_reserve); | |
422 | ||
423 | /** | |
424 | * nla_reserve_64bit - reserve room for attribute on the skb and align it | |
425 | * @skb: socket buffer to reserve room on | |
426 | * @attrtype: attribute type | |
427 | * @attrlen: length of attribute payload | |
428 | * @padattr: attribute type for the padding | |
429 | * | |
430 | * Adds a netlink attribute header to a socket buffer and reserves | |
431 | * room for the payload but does not copy it. It also ensure that this | |
432 | * attribute will have a 64-bit aligned nla_data() area. | |
433 | * | |
434 | * Returns NULL if the tailroom of the skb is insufficient to store | |
435 | * the attribute header and payload. | |
436 | */ | |
437 | struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, int attrlen, | |
438 | int padattr) | |
439 | { | |
440 | size_t len; | |
441 | ||
442 | if (nla_need_padding_for_64bit(skb)) | |
443 | len = nla_total_size_64bit(attrlen); | |
444 | else | |
445 | len = nla_total_size(attrlen); | |
446 | if (unlikely(skb_tailroom(skb) < len)) | |
447 | return NULL; | |
448 | ||
449 | return __nla_reserve_64bit(skb, attrtype, attrlen, padattr); | |
450 | } | |
451 | EXPORT_SYMBOL(nla_reserve_64bit); | |
452 | ||
453 | /** | |
454 | * nla_reserve_nohdr - reserve room for attribute without header | |
455 | * @skb: socket buffer to reserve room on | |
456 | * @attrlen: length of attribute payload | |
457 | * | |
458 | * Reserves room for attribute payload without a header. | |
459 | * | |
460 | * Returns NULL if the tailroom of the skb is insufficient to store | |
461 | * the attribute payload. | |
462 | */ | |
463 | void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen) | |
464 | { | |
465 | if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) | |
466 | return NULL; | |
467 | ||
468 | return __nla_reserve_nohdr(skb, attrlen); | |
469 | } | |
470 | EXPORT_SYMBOL(nla_reserve_nohdr); | |
471 | ||
472 | /** | |
473 | * __nla_put - Add a netlink attribute to a socket buffer | |
474 | * @skb: socket buffer to add attribute to | |
475 | * @attrtype: attribute type | |
476 | * @attrlen: length of attribute payload | |
477 | * @data: head of attribute payload | |
478 | * | |
479 | * The caller is responsible to ensure that the skb provides enough | |
480 | * tailroom for the attribute header and payload. | |
481 | */ | |
482 | void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, | |
483 | const void *data) | |
484 | { | |
485 | struct nlattr *nla; | |
486 | ||
487 | nla = __nla_reserve(skb, attrtype, attrlen); | |
488 | memcpy(nla_data(nla), data, attrlen); | |
489 | } | |
490 | EXPORT_SYMBOL(__nla_put); | |
491 | ||
492 | /** | |
493 | * __nla_put_64bit - Add a netlink attribute to a socket buffer and align it | |
494 | * @skb: socket buffer to add attribute to | |
495 | * @attrtype: attribute type | |
496 | * @attrlen: length of attribute payload | |
497 | * @data: head of attribute payload | |
498 | * @padattr: attribute type for the padding | |
499 | * | |
500 | * The caller is responsible to ensure that the skb provides enough | |
501 | * tailroom for the attribute header and payload. | |
502 | */ | |
503 | void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, | |
504 | const void *data, int padattr) | |
505 | { | |
506 | struct nlattr *nla; | |
507 | ||
508 | nla = __nla_reserve_64bit(skb, attrtype, attrlen, padattr); | |
509 | memcpy(nla_data(nla), data, attrlen); | |
510 | } | |
511 | EXPORT_SYMBOL(__nla_put_64bit); | |
512 | ||
513 | /** | |
514 | * __nla_put_nohdr - Add a netlink attribute without header | |
515 | * @skb: socket buffer to add attribute to | |
516 | * @attrlen: length of attribute payload | |
517 | * @data: head of attribute payload | |
518 | * | |
519 | * The caller is responsible to ensure that the skb provides enough | |
520 | * tailroom for the attribute payload. | |
521 | */ | |
522 | void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data) | |
523 | { | |
524 | void *start; | |
525 | ||
526 | start = __nla_reserve_nohdr(skb, attrlen); | |
527 | memcpy(start, data, attrlen); | |
528 | } | |
529 | EXPORT_SYMBOL(__nla_put_nohdr); | |
530 | ||
531 | /** | |
532 | * nla_put - Add a netlink attribute to a socket buffer | |
533 | * @skb: socket buffer to add attribute to | |
534 | * @attrtype: attribute type | |
535 | * @attrlen: length of attribute payload | |
536 | * @data: head of attribute payload | |
537 | * | |
538 | * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store | |
539 | * the attribute header and payload. | |
540 | */ | |
541 | int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data) | |
542 | { | |
543 | if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen))) | |
544 | return -EMSGSIZE; | |
545 | ||
546 | __nla_put(skb, attrtype, attrlen, data); | |
547 | return 0; | |
548 | } | |
549 | EXPORT_SYMBOL(nla_put); | |
550 | ||
551 | /** | |
552 | * nla_put_64bit - Add a netlink attribute to a socket buffer and align it | |
553 | * @skb: socket buffer to add attribute to | |
554 | * @attrtype: attribute type | |
555 | * @attrlen: length of attribute payload | |
556 | * @data: head of attribute payload | |
557 | * @padattr: attribute type for the padding | |
558 | * | |
559 | * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store | |
560 | * the attribute header and payload. | |
561 | */ | |
562 | int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, | |
563 | const void *data, int padattr) | |
564 | { | |
565 | size_t len; | |
566 | ||
567 | if (nla_need_padding_for_64bit(skb)) | |
568 | len = nla_total_size_64bit(attrlen); | |
569 | else | |
570 | len = nla_total_size(attrlen); | |
571 | if (unlikely(skb_tailroom(skb) < len)) | |
572 | return -EMSGSIZE; | |
573 | ||
574 | __nla_put_64bit(skb, attrtype, attrlen, data, padattr); | |
575 | return 0; | |
576 | } | |
577 | EXPORT_SYMBOL(nla_put_64bit); | |
578 | ||
579 | /** | |
580 | * nla_put_nohdr - Add a netlink attribute without header | |
581 | * @skb: socket buffer to add attribute to | |
582 | * @attrlen: length of attribute payload | |
583 | * @data: head of attribute payload | |
584 | * | |
585 | * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store | |
586 | * the attribute payload. | |
587 | */ | |
588 | int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data) | |
589 | { | |
590 | if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) | |
591 | return -EMSGSIZE; | |
592 | ||
593 | __nla_put_nohdr(skb, attrlen, data); | |
594 | return 0; | |
595 | } | |
596 | EXPORT_SYMBOL(nla_put_nohdr); | |
597 | ||
598 | /** | |
599 | * nla_append - Add a netlink attribute without header or padding | |
600 | * @skb: socket buffer to add attribute to | |
601 | * @attrlen: length of attribute payload | |
602 | * @data: head of attribute payload | |
603 | * | |
604 | * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store | |
605 | * the attribute payload. | |
606 | */ | |
607 | int nla_append(struct sk_buff *skb, int attrlen, const void *data) | |
608 | { | |
609 | if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) | |
610 | return -EMSGSIZE; | |
611 | ||
612 | memcpy(skb_put(skb, attrlen), data, attrlen); | |
613 | return 0; | |
614 | } | |
615 | EXPORT_SYMBOL(nla_append); | |
616 | #endif |