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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
bfa83a9e TG |
2 | /* |
3 | * NETLINK Netlink attributes | |
4 | * | |
5 | * Authors: Thomas Graf <tgraf@suug.ch> | |
6 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> | |
7 | */ | |
8 | ||
8bc3bcc9 | 9 | #include <linux/export.h> |
bfa83a9e TG |
10 | #include <linux/kernel.h> |
11 | #include <linux/errno.h> | |
12 | #include <linux/jiffies.h> | |
bfa83a9e TG |
13 | #include <linux/skbuff.h> |
14 | #include <linux/string.h> | |
15 | #include <linux/types.h> | |
16 | #include <net/netlink.h> | |
17 | ||
6e237d09 DA |
18 | /* For these data types, attribute length should be exactly the given |
19 | * size. However, to maintain compatibility with broken commands, if the | |
20 | * attribute length does not match the expected size a warning is emitted | |
21 | * to the user that the command is sending invalid data and needs to be fixed. | |
22 | */ | |
28033ae4 | 23 | static const u8 nla_attr_len[NLA_TYPE_MAX+1] = { |
bfa83a9e TG |
24 | [NLA_U8] = sizeof(u8), |
25 | [NLA_U16] = sizeof(u16), | |
26 | [NLA_U32] = sizeof(u32), | |
27 | [NLA_U64] = sizeof(u64), | |
9eca2eb9 JA |
28 | [NLA_S8] = sizeof(s8), |
29 | [NLA_S16] = sizeof(s16), | |
30 | [NLA_S32] = sizeof(s32), | |
31 | [NLA_S64] = sizeof(s64), | |
bfa83a9e TG |
32 | }; |
33 | ||
28033ae4 | 34 | static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = { |
6e237d09 DA |
35 | [NLA_U8] = sizeof(u8), |
36 | [NLA_U16] = sizeof(u16), | |
37 | [NLA_U32] = sizeof(u32), | |
38 | [NLA_U64] = sizeof(u64), | |
28033ae4 DA |
39 | [NLA_MSECS] = sizeof(u64), |
40 | [NLA_NESTED] = NLA_HDRLEN, | |
6e237d09 DA |
41 | [NLA_S8] = sizeof(s8), |
42 | [NLA_S16] = sizeof(s16), | |
43 | [NLA_S32] = sizeof(s32), | |
44 | [NLA_S64] = sizeof(s64), | |
28033ae4 DA |
45 | }; |
46 | ||
64c83d83 | 47 | static int validate_nla_bitfield32(const struct nlattr *nla, |
48fde90a | 48 | const u32 *valid_flags_mask) |
64c83d83 JHS |
49 | { |
50 | const struct nla_bitfield32 *bf = nla_data(nla); | |
64c83d83 | 51 | |
48fde90a | 52 | if (!valid_flags_mask) |
64c83d83 JHS |
53 | return -EINVAL; |
54 | ||
55 | /*disallow invalid bit selector */ | |
56 | if (bf->selector & ~*valid_flags_mask) | |
57 | return -EINVAL; | |
58 | ||
59 | /*disallow invalid bit values */ | |
60 | if (bf->value & ~*valid_flags_mask) | |
61 | return -EINVAL; | |
62 | ||
63 | /*disallow valid bit values that are not selected*/ | |
64 | if (bf->value & ~bf->selector) | |
65 | return -EINVAL; | |
66 | ||
67 | return 0; | |
68 | } | |
69 | ||
1501d135 JB |
70 | static int nla_validate_array(const struct nlattr *head, int len, int maxtype, |
71 | const struct nla_policy *policy, | |
8cb08174 JB |
72 | struct netlink_ext_ack *extack, |
73 | unsigned int validate) | |
1501d135 JB |
74 | { |
75 | const struct nlattr *entry; | |
76 | int rem; | |
77 | ||
78 | nla_for_each_attr(entry, head, len, rem) { | |
79 | int ret; | |
80 | ||
81 | if (nla_len(entry) == 0) | |
82 | continue; | |
83 | ||
84 | if (nla_len(entry) < NLA_HDRLEN) { | |
85 | NL_SET_ERR_MSG_ATTR(extack, entry, | |
86 | "Array element too short"); | |
87 | return -ERANGE; | |
88 | } | |
89 | ||
8cb08174 JB |
90 | ret = __nla_validate(nla_data(entry), nla_len(entry), |
91 | maxtype, policy, validate, extack); | |
1501d135 JB |
92 | if (ret < 0) |
93 | return ret; | |
94 | } | |
95 | ||
96 | return 0; | |
97 | } | |
98 | ||
3e48be05 JB |
99 | static int nla_validate_int_range(const struct nla_policy *pt, |
100 | const struct nlattr *nla, | |
101 | struct netlink_ext_ack *extack) | |
102 | { | |
103 | bool validate_min, validate_max; | |
104 | s64 value; | |
105 | ||
106 | validate_min = pt->validation_type == NLA_VALIDATE_RANGE || | |
107 | pt->validation_type == NLA_VALIDATE_MIN; | |
108 | validate_max = pt->validation_type == NLA_VALIDATE_RANGE || | |
109 | pt->validation_type == NLA_VALIDATE_MAX; | |
110 | ||
111 | switch (pt->type) { | |
112 | case NLA_U8: | |
113 | value = nla_get_u8(nla); | |
114 | break; | |
115 | case NLA_U16: | |
116 | value = nla_get_u16(nla); | |
117 | break; | |
118 | case NLA_U32: | |
119 | value = nla_get_u32(nla); | |
120 | break; | |
121 | case NLA_S8: | |
122 | value = nla_get_s8(nla); | |
123 | break; | |
124 | case NLA_S16: | |
125 | value = nla_get_s16(nla); | |
126 | break; | |
127 | case NLA_S32: | |
128 | value = nla_get_s32(nla); | |
129 | break; | |
130 | case NLA_S64: | |
131 | value = nla_get_s64(nla); | |
132 | break; | |
133 | case NLA_U64: | |
134 | /* treat this one specially, since it may not fit into s64 */ | |
135 | if ((validate_min && nla_get_u64(nla) < pt->min) || | |
136 | (validate_max && nla_get_u64(nla) > pt->max)) { | |
137 | NL_SET_ERR_MSG_ATTR(extack, nla, | |
138 | "integer out of range"); | |
139 | return -ERANGE; | |
140 | } | |
141 | return 0; | |
142 | default: | |
143 | WARN_ON(1); | |
144 | return -EINVAL; | |
145 | } | |
146 | ||
147 | if ((validate_min && value < pt->min) || | |
148 | (validate_max && value > pt->max)) { | |
149 | NL_SET_ERR_MSG_ATTR(extack, nla, | |
150 | "integer out of range"); | |
151 | return -ERANGE; | |
152 | } | |
153 | ||
154 | return 0; | |
155 | } | |
156 | ||
3654654f | 157 | static int validate_nla(const struct nlattr *nla, int maxtype, |
8cb08174 | 158 | const struct nla_policy *policy, unsigned int validate, |
c29f1845 | 159 | struct netlink_ext_ack *extack) |
bfa83a9e | 160 | { |
56738f46 | 161 | u16 strict_start_type = policy[0].strict_start_type; |
ef7c79ed | 162 | const struct nla_policy *pt; |
8f4c1f9b | 163 | int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla); |
c29f1845 | 164 | int err = -ERANGE; |
bfa83a9e | 165 | |
56738f46 JB |
166 | if (strict_start_type && type >= strict_start_type) |
167 | validate |= NL_VALIDATE_STRICT; | |
168 | ||
8f4c1f9b | 169 | if (type <= 0 || type > maxtype) |
bfa83a9e TG |
170 | return 0; |
171 | ||
8f4c1f9b | 172 | pt = &policy[type]; |
bfa83a9e TG |
173 | |
174 | BUG_ON(pt->type > NLA_TYPE_MAX); | |
175 | ||
b60b87fc JB |
176 | if ((nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) || |
177 | (pt->type == NLA_EXACT_LEN_WARN && attrlen != pt->len)) { | |
6e237d09 DA |
178 | pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n", |
179 | current->comm, type); | |
8cb08174 JB |
180 | if (validate & NL_VALIDATE_STRICT_ATTRS) { |
181 | NL_SET_ERR_MSG_ATTR(extack, nla, | |
182 | "invalid attribute length"); | |
183 | return -EINVAL; | |
184 | } | |
28033ae4 DA |
185 | } |
186 | ||
b424e432 MK |
187 | if (validate & NL_VALIDATE_NESTED) { |
188 | if ((pt->type == NLA_NESTED || pt->type == NLA_NESTED_ARRAY) && | |
189 | !(nla->nla_type & NLA_F_NESTED)) { | |
190 | NL_SET_ERR_MSG_ATTR(extack, nla, | |
191 | "NLA_F_NESTED is missing"); | |
192 | return -EINVAL; | |
193 | } | |
194 | if (pt->type != NLA_NESTED && pt->type != NLA_NESTED_ARRAY && | |
195 | pt->type != NLA_UNSPEC && (nla->nla_type & NLA_F_NESTED)) { | |
196 | NL_SET_ERR_MSG_ATTR(extack, nla, | |
197 | "NLA_F_NESTED not expected"); | |
198 | return -EINVAL; | |
199 | } | |
200 | } | |
201 | ||
a5531a5d | 202 | switch (pt->type) { |
b60b87fc JB |
203 | case NLA_EXACT_LEN: |
204 | if (attrlen != pt->len) | |
c29f1845 | 205 | goto out_err; |
b60b87fc JB |
206 | break; |
207 | ||
568b742a | 208 | case NLA_REJECT: |
c29f1845 JB |
209 | if (extack && pt->validation_data) { |
210 | NL_SET_BAD_ATTR(extack, nla); | |
211 | extack->_msg = pt->validation_data; | |
212 | return -EINVAL; | |
213 | } | |
214 | err = -EINVAL; | |
215 | goto out_err; | |
568b742a | 216 | |
a5531a5d TG |
217 | case NLA_FLAG: |
218 | if (attrlen > 0) | |
c29f1845 | 219 | goto out_err; |
a5531a5d | 220 | break; |
bfa83a9e | 221 | |
64c83d83 JHS |
222 | case NLA_BITFIELD32: |
223 | if (attrlen != sizeof(struct nla_bitfield32)) | |
c29f1845 | 224 | goto out_err; |
64c83d83 | 225 | |
c29f1845 JB |
226 | err = validate_nla_bitfield32(nla, pt->validation_data); |
227 | if (err) | |
228 | goto out_err; | |
229 | break; | |
64c83d83 | 230 | |
a5531a5d TG |
231 | case NLA_NUL_STRING: |
232 | if (pt->len) | |
233 | minlen = min_t(int, attrlen, pt->len + 1); | |
234 | else | |
235 | minlen = attrlen; | |
bfa83a9e | 236 | |
c29f1845 JB |
237 | if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) { |
238 | err = -EINVAL; | |
239 | goto out_err; | |
240 | } | |
a5531a5d TG |
241 | /* fall through */ |
242 | ||
243 | case NLA_STRING: | |
244 | if (attrlen < 1) | |
c29f1845 | 245 | goto out_err; |
a5531a5d TG |
246 | |
247 | if (pt->len) { | |
248 | char *buf = nla_data(nla); | |
249 | ||
250 | if (buf[attrlen - 1] == '\0') | |
251 | attrlen--; | |
252 | ||
253 | if (attrlen > pt->len) | |
c29f1845 | 254 | goto out_err; |
a5531a5d TG |
255 | } |
256 | break; | |
257 | ||
d30045a0 JB |
258 | case NLA_BINARY: |
259 | if (pt->len && attrlen > pt->len) | |
c29f1845 | 260 | goto out_err; |
d30045a0 JB |
261 | break; |
262 | ||
ea5693cc PM |
263 | case NLA_NESTED: |
264 | /* a nested attributes is allowed to be empty; if its not, | |
265 | * it must have a size of at least NLA_HDRLEN. | |
266 | */ | |
267 | if (attrlen == 0) | |
268 | break; | |
9a659a35 JB |
269 | if (attrlen < NLA_HDRLEN) |
270 | goto out_err; | |
271 | if (pt->validation_data) { | |
8cb08174 JB |
272 | err = __nla_validate(nla_data(nla), nla_len(nla), pt->len, |
273 | pt->validation_data, validate, | |
274 | extack); | |
9a659a35 JB |
275 | if (err < 0) { |
276 | /* | |
277 | * return directly to preserve the inner | |
278 | * error message/attribute pointer | |
279 | */ | |
280 | return err; | |
281 | } | |
282 | } | |
283 | break; | |
1501d135 JB |
284 | case NLA_NESTED_ARRAY: |
285 | /* a nested array attribute is allowed to be empty; if its not, | |
286 | * it must have a size of at least NLA_HDRLEN. | |
287 | */ | |
288 | if (attrlen == 0) | |
289 | break; | |
290 | if (attrlen < NLA_HDRLEN) | |
291 | goto out_err; | |
292 | if (pt->validation_data) { | |
293 | int err; | |
294 | ||
295 | err = nla_validate_array(nla_data(nla), nla_len(nla), | |
296 | pt->len, pt->validation_data, | |
8cb08174 | 297 | extack, validate); |
1501d135 JB |
298 | if (err < 0) { |
299 | /* | |
300 | * return directly to preserve the inner | |
301 | * error message/attribute pointer | |
302 | */ | |
303 | return err; | |
304 | } | |
305 | } | |
306 | break; | |
6f455f5f JB |
307 | |
308 | case NLA_UNSPEC: | |
8cb08174 JB |
309 | if (validate & NL_VALIDATE_UNSPEC) { |
310 | NL_SET_ERR_MSG_ATTR(extack, nla, | |
311 | "Unsupported attribute"); | |
312 | return -EINVAL; | |
313 | } | |
314 | /* fall through */ | |
6f455f5f JB |
315 | case NLA_MIN_LEN: |
316 | if (attrlen < pt->len) | |
317 | goto out_err; | |
318 | break; | |
319 | ||
a5531a5d TG |
320 | default: |
321 | if (pt->len) | |
322 | minlen = pt->len; | |
6f455f5f | 323 | else |
a5531a5d TG |
324 | minlen = nla_attr_minlen[pt->type]; |
325 | ||
326 | if (attrlen < minlen) | |
c29f1845 | 327 | goto out_err; |
a5531a5d | 328 | } |
bfa83a9e | 329 | |
3e48be05 JB |
330 | /* further validation */ |
331 | switch (pt->validation_type) { | |
332 | case NLA_VALIDATE_NONE: | |
333 | /* nothing to do */ | |
334 | break; | |
335 | case NLA_VALIDATE_RANGE: | |
336 | case NLA_VALIDATE_MIN: | |
337 | case NLA_VALIDATE_MAX: | |
338 | err = nla_validate_int_range(pt, nla, extack); | |
339 | if (err) | |
340 | return err; | |
341 | break; | |
33188bd6 JB |
342 | case NLA_VALIDATE_FUNCTION: |
343 | if (pt->validate) { | |
344 | err = pt->validate(nla, extack); | |
345 | if (err) | |
346 | return err; | |
347 | } | |
348 | break; | |
3e48be05 JB |
349 | } |
350 | ||
bfa83a9e | 351 | return 0; |
c29f1845 JB |
352 | out_err: |
353 | NL_SET_ERR_MSG_ATTR(extack, nla, "Attribute failed policy validation"); | |
354 | return err; | |
bfa83a9e TG |
355 | } |
356 | ||
8cb08174 JB |
357 | static int __nla_validate_parse(const struct nlattr *head, int len, int maxtype, |
358 | const struct nla_policy *policy, | |
359 | unsigned int validate, | |
360 | struct netlink_ext_ack *extack, | |
361 | struct nlattr **tb) | |
362 | { | |
363 | const struct nlattr *nla; | |
364 | int rem; | |
365 | ||
366 | if (tb) | |
367 | memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); | |
368 | ||
369 | nla_for_each_attr(nla, head, len, rem) { | |
370 | u16 type = nla_type(nla); | |
371 | ||
372 | if (type == 0 || type > maxtype) { | |
373 | if (validate & NL_VALIDATE_MAXTYPE) { | |
d54a16b2 MK |
374 | NL_SET_ERR_MSG_ATTR(extack, nla, |
375 | "Unknown attribute type"); | |
8cb08174 JB |
376 | return -EINVAL; |
377 | } | |
378 | continue; | |
379 | } | |
380 | if (policy) { | |
381 | int err = validate_nla(nla, maxtype, policy, | |
382 | validate, extack); | |
383 | ||
384 | if (err < 0) | |
385 | return err; | |
386 | } | |
387 | ||
388 | if (tb) | |
389 | tb[type] = (struct nlattr *)nla; | |
390 | } | |
391 | ||
392 | if (unlikely(rem > 0)) { | |
393 | pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n", | |
394 | rem, current->comm); | |
395 | NL_SET_ERR_MSG(extack, "bytes leftover after parsing attributes"); | |
396 | if (validate & NL_VALIDATE_TRAILING) | |
397 | return -EINVAL; | |
398 | } | |
399 | ||
400 | return 0; | |
401 | } | |
402 | ||
bfa83a9e | 403 | /** |
8cb08174 | 404 | * __nla_validate - Validate a stream of attributes |
bfa83a9e TG |
405 | * @head: head of attribute stream |
406 | * @len: length of attribute stream | |
407 | * @maxtype: maximum attribute type to be expected | |
408 | * @policy: validation policy | |
8cb08174 | 409 | * @validate: validation strictness |
fceb6435 | 410 | * @extack: extended ACK report struct |
bfa83a9e TG |
411 | * |
412 | * Validates all attributes in the specified attribute stream against the | |
8cb08174 JB |
413 | * specified policy. Validation depends on the validate flags passed, see |
414 | * &enum netlink_validation for more details on that. | |
415 | * See documenation of struct nla_policy for more details. | |
bfa83a9e TG |
416 | * |
417 | * Returns 0 on success or a negative error code. | |
418 | */ | |
8cb08174 JB |
419 | int __nla_validate(const struct nlattr *head, int len, int maxtype, |
420 | const struct nla_policy *policy, unsigned int validate, | |
421 | struct netlink_ext_ack *extack) | |
bfa83a9e | 422 | { |
8cb08174 JB |
423 | return __nla_validate_parse(head, len, maxtype, policy, validate, |
424 | extack, NULL); | |
bfa83a9e | 425 | } |
8cb08174 | 426 | EXPORT_SYMBOL(__nla_validate); |
bfa83a9e | 427 | |
e487eb99 HE |
428 | /** |
429 | * nla_policy_len - Determin the max. length of a policy | |
430 | * @policy: policy to use | |
431 | * @n: number of policies | |
432 | * | |
433 | * Determines the max. length of the policy. It is currently used | |
434 | * to allocated Netlink buffers roughly the size of the actual | |
435 | * message. | |
436 | * | |
437 | * Returns 0 on success or a negative error code. | |
438 | */ | |
439 | int | |
440 | nla_policy_len(const struct nla_policy *p, int n) | |
441 | { | |
442 | int i, len = 0; | |
443 | ||
e3fa3aff | 444 | for (i = 0; i < n; i++, p++) { |
e487eb99 HE |
445 | if (p->len) |
446 | len += nla_total_size(p->len); | |
28033ae4 DA |
447 | else if (nla_attr_len[p->type]) |
448 | len += nla_total_size(nla_attr_len[p->type]); | |
e487eb99 HE |
449 | else if (nla_attr_minlen[p->type]) |
450 | len += nla_total_size(nla_attr_minlen[p->type]); | |
451 | } | |
452 | ||
453 | return len; | |
454 | } | |
6d6a138f | 455 | EXPORT_SYMBOL(nla_policy_len); |
e487eb99 | 456 | |
bfa83a9e | 457 | /** |
8cb08174 | 458 | * __nla_parse - Parse a stream of attributes into a tb buffer |
bfa83a9e TG |
459 | * @tb: destination array with maxtype+1 elements |
460 | * @maxtype: maximum attribute type to be expected | |
461 | * @head: head of attribute stream | |
462 | * @len: length of attribute stream | |
10b595af | 463 | * @policy: validation policy |
8cb08174 JB |
464 | * @validate: validation strictness |
465 | * @extack: extended ACK pointer | |
bfa83a9e TG |
466 | * |
467 | * Parses a stream of attributes and stores a pointer to each attribute in | |
8cb08174 JB |
468 | * the tb array accessible via the attribute type. |
469 | * Validation is controlled by the @validate parameter. | |
bfa83a9e TG |
470 | * |
471 | * Returns 0 on success or a negative error code. | |
472 | */ | |
8cb08174 JB |
473 | int __nla_parse(struct nlattr **tb, int maxtype, |
474 | const struct nlattr *head, int len, | |
475 | const struct nla_policy *policy, unsigned int validate, | |
476 | struct netlink_ext_ack *extack) | |
a5f6cba2 | 477 | { |
8cb08174 JB |
478 | return __nla_validate_parse(head, len, maxtype, policy, validate, |
479 | extack, tb); | |
a5f6cba2 | 480 | } |
8cb08174 | 481 | EXPORT_SYMBOL(__nla_parse); |
a5f6cba2 | 482 | |
bfa83a9e TG |
483 | /** |
484 | * nla_find - Find a specific attribute in a stream of attributes | |
485 | * @head: head of attribute stream | |
486 | * @len: length of attribute stream | |
487 | * @attrtype: type of attribute to look for | |
488 | * | |
489 | * Returns the first attribute in the stream matching the specified type. | |
490 | */ | |
3654654f | 491 | struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype) |
bfa83a9e | 492 | { |
3654654f | 493 | const struct nlattr *nla; |
bfa83a9e TG |
494 | int rem; |
495 | ||
496 | nla_for_each_attr(nla, head, len, rem) | |
8f4c1f9b | 497 | if (nla_type(nla) == attrtype) |
3654654f | 498 | return (struct nlattr *)nla; |
bfa83a9e TG |
499 | |
500 | return NULL; | |
501 | } | |
6d6a138f | 502 | EXPORT_SYMBOL(nla_find); |
bfa83a9e TG |
503 | |
504 | /** | |
505 | * nla_strlcpy - Copy string attribute payload into a sized buffer | |
506 | * @dst: where to copy the string to | |
10b595af | 507 | * @nla: attribute to copy the string from |
bfa83a9e TG |
508 | * @dstsize: size of destination buffer |
509 | * | |
510 | * Copies at most dstsize - 1 bytes into the destination buffer. | |
511 | * The result is always a valid NUL-terminated string. Unlike | |
512 | * strlcpy the destination buffer is always padded out. | |
513 | * | |
514 | * Returns the length of the source buffer. | |
515 | */ | |
516 | size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize) | |
517 | { | |
518 | size_t srclen = nla_len(nla); | |
519 | char *src = nla_data(nla); | |
520 | ||
521 | if (srclen > 0 && src[srclen - 1] == '\0') | |
522 | srclen--; | |
523 | ||
524 | if (dstsize > 0) { | |
525 | size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen; | |
526 | ||
527 | memset(dst, 0, dstsize); | |
528 | memcpy(dst, src, len); | |
529 | } | |
530 | ||
531 | return srclen; | |
532 | } | |
6d6a138f | 533 | EXPORT_SYMBOL(nla_strlcpy); |
bfa83a9e | 534 | |
2cf0c8b3 PS |
535 | /** |
536 | * nla_strdup - Copy string attribute payload into a newly allocated buffer | |
537 | * @nla: attribute to copy the string from | |
538 | * @flags: the type of memory to allocate (see kmalloc). | |
539 | * | |
540 | * Returns a pointer to the allocated buffer or NULL on error. | |
541 | */ | |
542 | char *nla_strdup(const struct nlattr *nla, gfp_t flags) | |
543 | { | |
544 | size_t srclen = nla_len(nla); | |
545 | char *src = nla_data(nla), *dst; | |
546 | ||
547 | if (srclen > 0 && src[srclen - 1] == '\0') | |
548 | srclen--; | |
549 | ||
550 | dst = kmalloc(srclen + 1, flags); | |
551 | if (dst != NULL) { | |
552 | memcpy(dst, src, srclen); | |
553 | dst[srclen] = '\0'; | |
554 | } | |
555 | return dst; | |
556 | } | |
557 | EXPORT_SYMBOL(nla_strdup); | |
558 | ||
bfa83a9e TG |
559 | /** |
560 | * nla_memcpy - Copy a netlink attribute into another memory area | |
561 | * @dest: where to copy to memcpy | |
562 | * @src: netlink attribute to copy from | |
563 | * @count: size of the destination area | |
564 | * | |
565 | * Note: The number of bytes copied is limited by the length of | |
566 | * attribute's payload. memcpy | |
567 | * | |
568 | * Returns the number of bytes copied. | |
569 | */ | |
b057efd4 | 570 | int nla_memcpy(void *dest, const struct nlattr *src, int count) |
bfa83a9e TG |
571 | { |
572 | int minlen = min_t(int, count, nla_len(src)); | |
573 | ||
574 | memcpy(dest, nla_data(src), minlen); | |
5899f047 JB |
575 | if (count > minlen) |
576 | memset(dest + minlen, 0, count - minlen); | |
bfa83a9e TG |
577 | |
578 | return minlen; | |
579 | } | |
6d6a138f | 580 | EXPORT_SYMBOL(nla_memcpy); |
bfa83a9e TG |
581 | |
582 | /** | |
583 | * nla_memcmp - Compare an attribute with sized memory area | |
584 | * @nla: netlink attribute | |
585 | * @data: memory area | |
586 | * @size: size of memory area | |
587 | */ | |
588 | int nla_memcmp(const struct nlattr *nla, const void *data, | |
589 | size_t size) | |
590 | { | |
591 | int d = nla_len(nla) - size; | |
592 | ||
593 | if (d == 0) | |
594 | d = memcmp(nla_data(nla), data, size); | |
595 | ||
596 | return d; | |
597 | } | |
6d6a138f | 598 | EXPORT_SYMBOL(nla_memcmp); |
bfa83a9e TG |
599 | |
600 | /** | |
601 | * nla_strcmp - Compare a string attribute against a string | |
602 | * @nla: netlink string attribute | |
603 | * @str: another string | |
604 | */ | |
605 | int nla_strcmp(const struct nlattr *nla, const char *str) | |
606 | { | |
8b7b9324 PN |
607 | int len = strlen(str); |
608 | char *buf = nla_data(nla); | |
609 | int attrlen = nla_len(nla); | |
610 | int d; | |
bfa83a9e | 611 | |
8b7b9324 PN |
612 | if (attrlen > 0 && buf[attrlen - 1] == '\0') |
613 | attrlen--; | |
614 | ||
615 | d = attrlen - len; | |
bfa83a9e TG |
616 | if (d == 0) |
617 | d = memcmp(nla_data(nla), str, len); | |
618 | ||
619 | return d; | |
620 | } | |
6d6a138f | 621 | EXPORT_SYMBOL(nla_strcmp); |
bfa83a9e | 622 | |
90800216 | 623 | #ifdef CONFIG_NET |
bfa83a9e TG |
624 | /** |
625 | * __nla_reserve - reserve room for attribute on the skb | |
626 | * @skb: socket buffer to reserve room on | |
627 | * @attrtype: attribute type | |
628 | * @attrlen: length of attribute payload | |
629 | * | |
630 | * Adds a netlink attribute header to a socket buffer and reserves | |
631 | * room for the payload but does not copy it. | |
632 | * | |
633 | * The caller is responsible to ensure that the skb provides enough | |
634 | * tailroom for the attribute header and payload. | |
635 | */ | |
636 | struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) | |
637 | { | |
638 | struct nlattr *nla; | |
639 | ||
4df864c1 | 640 | nla = skb_put(skb, nla_total_size(attrlen)); |
bfa83a9e TG |
641 | nla->nla_type = attrtype; |
642 | nla->nla_len = nla_attr_size(attrlen); | |
643 | ||
644 | memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen)); | |
645 | ||
646 | return nla; | |
647 | } | |
90800216 | 648 | EXPORT_SYMBOL(__nla_reserve); |
bfa83a9e | 649 | |
089bf1a6 ND |
650 | /** |
651 | * __nla_reserve_64bit - reserve room for attribute on the skb and align it | |
652 | * @skb: socket buffer to reserve room on | |
653 | * @attrtype: attribute type | |
654 | * @attrlen: length of attribute payload | |
11a99573 | 655 | * @padattr: attribute type for the padding |
089bf1a6 ND |
656 | * |
657 | * Adds a netlink attribute header to a socket buffer and reserves | |
658 | * room for the payload but does not copy it. It also ensure that this | |
11a99573 | 659 | * attribute will have a 64-bit aligned nla_data() area. |
089bf1a6 ND |
660 | * |
661 | * The caller is responsible to ensure that the skb provides enough | |
662 | * tailroom for the attribute header and payload. | |
663 | */ | |
664 | struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, | |
665 | int attrlen, int padattr) | |
666 | { | |
667 | if (nla_need_padding_for_64bit(skb)) | |
668 | nla_align_64bit(skb, padattr); | |
669 | ||
670 | return __nla_reserve(skb, attrtype, attrlen); | |
671 | } | |
672 | EXPORT_SYMBOL(__nla_reserve_64bit); | |
673 | ||
fe4944e5 TG |
674 | /** |
675 | * __nla_reserve_nohdr - reserve room for attribute without header | |
676 | * @skb: socket buffer to reserve room on | |
677 | * @attrlen: length of attribute payload | |
678 | * | |
679 | * Reserves room for attribute payload without a header. | |
680 | * | |
681 | * The caller is responsible to ensure that the skb provides enough | |
682 | * tailroom for the payload. | |
683 | */ | |
684 | void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen) | |
685 | { | |
b952f4df | 686 | return skb_put_zero(skb, NLA_ALIGN(attrlen)); |
fe4944e5 | 687 | } |
90800216 | 688 | EXPORT_SYMBOL(__nla_reserve_nohdr); |
fe4944e5 | 689 | |
bfa83a9e TG |
690 | /** |
691 | * nla_reserve - reserve room for attribute on the skb | |
692 | * @skb: socket buffer to reserve room on | |
693 | * @attrtype: attribute type | |
694 | * @attrlen: length of attribute payload | |
695 | * | |
696 | * Adds a netlink attribute header to a socket buffer and reserves | |
697 | * room for the payload but does not copy it. | |
698 | * | |
699 | * Returns NULL if the tailroom of the skb is insufficient to store | |
700 | * the attribute header and payload. | |
701 | */ | |
702 | struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) | |
703 | { | |
704 | if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen))) | |
705 | return NULL; | |
706 | ||
707 | return __nla_reserve(skb, attrtype, attrlen); | |
708 | } | |
90800216 | 709 | EXPORT_SYMBOL(nla_reserve); |
bfa83a9e | 710 | |
089bf1a6 ND |
711 | /** |
712 | * nla_reserve_64bit - reserve room for attribute on the skb and align it | |
713 | * @skb: socket buffer to reserve room on | |
714 | * @attrtype: attribute type | |
715 | * @attrlen: length of attribute payload | |
11a99573 | 716 | * @padattr: attribute type for the padding |
089bf1a6 ND |
717 | * |
718 | * Adds a netlink attribute header to a socket buffer and reserves | |
719 | * room for the payload but does not copy it. It also ensure that this | |
11a99573 | 720 | * attribute will have a 64-bit aligned nla_data() area. |
089bf1a6 ND |
721 | * |
722 | * Returns NULL if the tailroom of the skb is insufficient to store | |
723 | * the attribute header and payload. | |
724 | */ | |
725 | struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, int attrlen, | |
726 | int padattr) | |
727 | { | |
728 | size_t len; | |
729 | ||
730 | if (nla_need_padding_for_64bit(skb)) | |
731 | len = nla_total_size_64bit(attrlen); | |
732 | else | |
733 | len = nla_total_size(attrlen); | |
734 | if (unlikely(skb_tailroom(skb) < len)) | |
735 | return NULL; | |
736 | ||
737 | return __nla_reserve_64bit(skb, attrtype, attrlen, padattr); | |
738 | } | |
739 | EXPORT_SYMBOL(nla_reserve_64bit); | |
740 | ||
fe4944e5 | 741 | /** |
10b595af | 742 | * nla_reserve_nohdr - reserve room for attribute without header |
fe4944e5 | 743 | * @skb: socket buffer to reserve room on |
10b595af | 744 | * @attrlen: length of attribute payload |
fe4944e5 TG |
745 | * |
746 | * Reserves room for attribute payload without a header. | |
747 | * | |
748 | * Returns NULL if the tailroom of the skb is insufficient to store | |
749 | * the attribute payload. | |
750 | */ | |
751 | void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen) | |
752 | { | |
753 | if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) | |
754 | return NULL; | |
755 | ||
756 | return __nla_reserve_nohdr(skb, attrlen); | |
757 | } | |
90800216 | 758 | EXPORT_SYMBOL(nla_reserve_nohdr); |
fe4944e5 | 759 | |
bfa83a9e TG |
760 | /** |
761 | * __nla_put - Add a netlink attribute to a socket buffer | |
762 | * @skb: socket buffer to add attribute to | |
763 | * @attrtype: attribute type | |
764 | * @attrlen: length of attribute payload | |
765 | * @data: head of attribute payload | |
766 | * | |
767 | * The caller is responsible to ensure that the skb provides enough | |
768 | * tailroom for the attribute header and payload. | |
769 | */ | |
770 | void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, | |
771 | const void *data) | |
772 | { | |
773 | struct nlattr *nla; | |
774 | ||
775 | nla = __nla_reserve(skb, attrtype, attrlen); | |
776 | memcpy(nla_data(nla), data, attrlen); | |
777 | } | |
90800216 | 778 | EXPORT_SYMBOL(__nla_put); |
bfa83a9e | 779 | |
089bf1a6 ND |
780 | /** |
781 | * __nla_put_64bit - Add a netlink attribute to a socket buffer and align it | |
782 | * @skb: socket buffer to add attribute to | |
783 | * @attrtype: attribute type | |
784 | * @attrlen: length of attribute payload | |
785 | * @data: head of attribute payload | |
11a99573 | 786 | * @padattr: attribute type for the padding |
089bf1a6 ND |
787 | * |
788 | * The caller is responsible to ensure that the skb provides enough | |
789 | * tailroom for the attribute header and payload. | |
790 | */ | |
791 | void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, | |
792 | const void *data, int padattr) | |
793 | { | |
794 | struct nlattr *nla; | |
795 | ||
796 | nla = __nla_reserve_64bit(skb, attrtype, attrlen, padattr); | |
797 | memcpy(nla_data(nla), data, attrlen); | |
798 | } | |
799 | EXPORT_SYMBOL(__nla_put_64bit); | |
800 | ||
fe4944e5 TG |
801 | /** |
802 | * __nla_put_nohdr - Add a netlink attribute without header | |
803 | * @skb: socket buffer to add attribute to | |
804 | * @attrlen: length of attribute payload | |
805 | * @data: head of attribute payload | |
806 | * | |
807 | * The caller is responsible to ensure that the skb provides enough | |
808 | * tailroom for the attribute payload. | |
809 | */ | |
810 | void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data) | |
811 | { | |
812 | void *start; | |
813 | ||
814 | start = __nla_reserve_nohdr(skb, attrlen); | |
815 | memcpy(start, data, attrlen); | |
816 | } | |
90800216 | 817 | EXPORT_SYMBOL(__nla_put_nohdr); |
bfa83a9e TG |
818 | |
819 | /** | |
820 | * nla_put - Add a netlink attribute to a socket buffer | |
821 | * @skb: socket buffer to add attribute to | |
822 | * @attrtype: attribute type | |
823 | * @attrlen: length of attribute payload | |
824 | * @data: head of attribute payload | |
825 | * | |
bc3ed28c | 826 | * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store |
bfa83a9e TG |
827 | * the attribute header and payload. |
828 | */ | |
829 | int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data) | |
830 | { | |
831 | if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen))) | |
bc3ed28c | 832 | return -EMSGSIZE; |
bfa83a9e TG |
833 | |
834 | __nla_put(skb, attrtype, attrlen, data); | |
835 | return 0; | |
836 | } | |
90800216 | 837 | EXPORT_SYMBOL(nla_put); |
bfa83a9e | 838 | |
089bf1a6 ND |
839 | /** |
840 | * nla_put_64bit - Add a netlink attribute to a socket buffer and align it | |
841 | * @skb: socket buffer to add attribute to | |
842 | * @attrtype: attribute type | |
843 | * @attrlen: length of attribute payload | |
844 | * @data: head of attribute payload | |
11a99573 | 845 | * @padattr: attribute type for the padding |
089bf1a6 ND |
846 | * |
847 | * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store | |
848 | * the attribute header and payload. | |
849 | */ | |
850 | int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, | |
851 | const void *data, int padattr) | |
852 | { | |
853 | size_t len; | |
854 | ||
855 | if (nla_need_padding_for_64bit(skb)) | |
856 | len = nla_total_size_64bit(attrlen); | |
857 | else | |
858 | len = nla_total_size(attrlen); | |
859 | if (unlikely(skb_tailroom(skb) < len)) | |
860 | return -EMSGSIZE; | |
861 | ||
862 | __nla_put_64bit(skb, attrtype, attrlen, data, padattr); | |
863 | return 0; | |
864 | } | |
865 | EXPORT_SYMBOL(nla_put_64bit); | |
866 | ||
fe4944e5 TG |
867 | /** |
868 | * nla_put_nohdr - Add a netlink attribute without header | |
869 | * @skb: socket buffer to add attribute to | |
870 | * @attrlen: length of attribute payload | |
871 | * @data: head of attribute payload | |
872 | * | |
bc3ed28c | 873 | * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store |
fe4944e5 TG |
874 | * the attribute payload. |
875 | */ | |
876 | int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data) | |
877 | { | |
878 | if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) | |
bc3ed28c | 879 | return -EMSGSIZE; |
fe4944e5 TG |
880 | |
881 | __nla_put_nohdr(skb, attrlen, data); | |
882 | return 0; | |
883 | } | |
90800216 | 884 | EXPORT_SYMBOL(nla_put_nohdr); |
bfa83a9e | 885 | |
01480e1c PM |
886 | /** |
887 | * nla_append - Add a netlink attribute without header or padding | |
888 | * @skb: socket buffer to add attribute to | |
889 | * @attrlen: length of attribute payload | |
890 | * @data: head of attribute payload | |
891 | * | |
bc3ed28c | 892 | * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store |
01480e1c PM |
893 | * the attribute payload. |
894 | */ | |
895 | int nla_append(struct sk_buff *skb, int attrlen, const void *data) | |
896 | { | |
897 | if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen))) | |
bc3ed28c | 898 | return -EMSGSIZE; |
01480e1c | 899 | |
59ae1d12 | 900 | skb_put_data(skb, data, attrlen); |
01480e1c PM |
901 | return 0; |
902 | } | |
90800216 HX |
903 | EXPORT_SYMBOL(nla_append); |
904 | #endif |