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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/netdevice.h>
13#include <linux/skbuff.h>
14#include <linux/string.h>
15#include <linux/types.h>
16#include <net/netlink.h>
17
18static const u16 nla_attr_minlen[NLA_TYPE_MAX+1] = {
19 [NLA_U8] = sizeof(u8),
20 [NLA_U16] = sizeof(u16),
21 [NLA_U32] = sizeof(u32),
22 [NLA_U64] = sizeof(u64),
23 [NLA_MSECS] = sizeof(u64),
24 [NLA_NESTED] = NLA_HDRLEN,
25 [NLA_S8] = sizeof(s8),
26 [NLA_S16] = sizeof(s16),
27 [NLA_S32] = sizeof(s32),
28 [NLA_S64] = sizeof(s64),
29};
30
31static int validate_nla(const struct nlattr *nla, int maxtype,
32 const struct nla_policy *policy)
33{
34 const struct nla_policy *pt;
35 int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla);
36
37 if (type <= 0 || type > maxtype)
38 return 0;
39
40 pt = &policy[type];
41
42 BUG_ON(pt->type > NLA_TYPE_MAX);
43
44 switch (pt->type) {
45 case NLA_FLAG:
46 if (attrlen > 0)
47 return -ERANGE;
48 break;
49
50 case NLA_NUL_STRING:
51 if (pt->len)
52 minlen = min_t(int, attrlen, pt->len + 1);
53 else
54 minlen = attrlen;
55
56 if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL)
57 return -EINVAL;
58 /* fall through */
59
60 case NLA_STRING:
61 if (attrlen < 1)
62 return -ERANGE;
63
64 if (pt->len) {
65 char *buf = nla_data(nla);
66
67 if (buf[attrlen - 1] == '\0')
68 attrlen--;
69
70 if (attrlen > pt->len)
71 return -ERANGE;
72 }
73 break;
74
75 case NLA_BINARY:
76 if (pt->len && attrlen > pt->len)
77 return -ERANGE;
78 break;
79
80 case NLA_NESTED_COMPAT:
81 if (attrlen < pt->len)
82 return -ERANGE;
83 if (attrlen < NLA_ALIGN(pt->len))
84 break;
85 if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN)
86 return -ERANGE;
87 nla = nla_data(nla) + NLA_ALIGN(pt->len);
88 if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN + nla_len(nla))
89 return -ERANGE;
90 break;
91 case NLA_NESTED:
92 /* a nested attributes is allowed to be empty; if its not,
93 * it must have a size of at least NLA_HDRLEN.
94 */
95 if (attrlen == 0)
96 break;
97 default:
98 if (pt->len)
99 minlen = pt->len;
100 else if (pt->type != NLA_UNSPEC)
101 minlen = nla_attr_minlen[pt->type];
102
103 if (attrlen < minlen)
104 return -ERANGE;
105 }
106
107 return 0;
108}
109
110/**
111 * nla_validate - Validate a stream of attributes
112 * @head: head of attribute stream
113 * @len: length of attribute stream
114 * @maxtype: maximum attribute type to be expected
115 * @policy: validation policy
116 *
117 * Validates all attributes in the specified attribute stream against the
118 * specified policy. Attributes with a type exceeding maxtype will be
119 * ignored. See documenation of struct nla_policy for more details.
120 *
121 * Returns 0 on success or a negative error code.
122 */
123int nla_validate(const struct nlattr *head, int len, int maxtype,
124 const struct nla_policy *policy)
125{
126 const struct nlattr *nla;
127 int rem, err;
128
129 nla_for_each_attr(nla, head, len, rem) {
130 err = validate_nla(nla, maxtype, policy);
131 if (err < 0)
132 goto errout;
133 }
134
135 err = 0;
136errout:
137 return err;
138}
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 */
151int
152nla_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
166/**
167 * nla_parse - Parse a stream of attributes into a tb buffer
168 * @tb: destination array with maxtype+1 elements
169 * @maxtype: maximum attribute type to be expected
170 * @head: head of attribute stream
171 * @len: length of attribute stream
172 * @policy: validation policy
173 *
174 * Parses a stream of attributes and stores a pointer to each attribute in
175 * the tb array accessible via the attribute type. Attributes with a type
176 * exceeding maxtype will be silently ignored for backwards compatibility
177 * reasons. policy may be set to NULL if no validation is required.
178 *
179 * Returns 0 on success or a negative error code.
180 */
181int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
182 int len, const struct nla_policy *policy)
183{
184 const struct nlattr *nla;
185 int rem, err;
186
187 memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
188
189 nla_for_each_attr(nla, head, len, rem) {
190 u16 type = nla_type(nla);
191
192 if (type > 0 && type <= maxtype) {
193 if (policy) {
194 err = validate_nla(nla, maxtype, policy);
195 if (err < 0)
196 goto errout;
197 }
198
199 tb[type] = (struct nlattr *)nla;
200 }
201 }
202
203 if (unlikely(rem > 0))
204 pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n",
205 rem, current->comm);
206
207 err = 0;
208errout:
209 return err;
210}
211
212/**
213 * nla_find - Find a specific attribute in a stream of attributes
214 * @head: head of attribute stream
215 * @len: length of attribute stream
216 * @attrtype: type of attribute to look for
217 *
218 * Returns the first attribute in the stream matching the specified type.
219 */
220struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype)
221{
222 const struct nlattr *nla;
223 int rem;
224
225 nla_for_each_attr(nla, head, len, rem)
226 if (nla_type(nla) == attrtype)
227 return (struct nlattr *)nla;
228
229 return NULL;
230}
231
232/**
233 * nla_strlcpy - Copy string attribute payload into a sized buffer
234 * @dst: where to copy the string to
235 * @nla: attribute to copy the string from
236 * @dstsize: size of destination buffer
237 *
238 * Copies at most dstsize - 1 bytes into the destination buffer.
239 * The result is always a valid NUL-terminated string. Unlike
240 * strlcpy the destination buffer is always padded out.
241 *
242 * Returns the length of the source buffer.
243 */
244size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize)
245{
246 size_t srclen = nla_len(nla);
247 char *src = nla_data(nla);
248
249 if (srclen > 0 && src[srclen - 1] == '\0')
250 srclen--;
251
252 if (dstsize > 0) {
253 size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen;
254
255 memset(dst, 0, dstsize);
256 memcpy(dst, src, len);
257 }
258
259 return srclen;
260}
261
262/**
263 * nla_memcpy - Copy a netlink attribute into another memory area
264 * @dest: where to copy to memcpy
265 * @src: netlink attribute to copy from
266 * @count: size of the destination area
267 *
268 * Note: The number of bytes copied is limited by the length of
269 * attribute's payload. memcpy
270 *
271 * Returns the number of bytes copied.
272 */
273int nla_memcpy(void *dest, const struct nlattr *src, int count)
274{
275 int minlen = min_t(int, count, nla_len(src));
276
277 memcpy(dest, nla_data(src), minlen);
278
279 return minlen;
280}
281
282/**
283 * nla_memcmp - Compare an attribute with sized memory area
284 * @nla: netlink attribute
285 * @data: memory area
286 * @size: size of memory area
287 */
288int nla_memcmp(const struct nlattr *nla, const void *data,
289 size_t size)
290{
291 int d = nla_len(nla) - size;
292
293 if (d == 0)
294 d = memcmp(nla_data(nla), data, size);
295
296 return d;
297}
298
299/**
300 * nla_strcmp - Compare a string attribute against a string
301 * @nla: netlink string attribute
302 * @str: another string
303 */
304int nla_strcmp(const struct nlattr *nla, const char *str)
305{
306 int len = strlen(str);
307 char *buf = nla_data(nla);
308 int attrlen = nla_len(nla);
309 int d;
310
311 if (attrlen > 0 && buf[attrlen - 1] == '\0')
312 attrlen--;
313
314 d = attrlen - len;
315 if (d == 0)
316 d = memcmp(nla_data(nla), str, len);
317
318 return d;
319}
320
321#ifdef CONFIG_NET
322/**
323 * __nla_reserve - reserve room for attribute on the skb
324 * @skb: socket buffer to reserve room on
325 * @attrtype: attribute type
326 * @attrlen: length of attribute payload
327 *
328 * Adds a netlink attribute header to a socket buffer and reserves
329 * room for the payload but does not copy it.
330 *
331 * The caller is responsible to ensure that the skb provides enough
332 * tailroom for the attribute header and payload.
333 */
334struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
335{
336 struct nlattr *nla;
337
338 nla = (struct nlattr *) skb_put(skb, nla_total_size(attrlen));
339 nla->nla_type = attrtype;
340 nla->nla_len = nla_attr_size(attrlen);
341
342 memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen));
343
344 return nla;
345}
346EXPORT_SYMBOL(__nla_reserve);
347
348/**
349 * __nla_reserve_nohdr - reserve room for attribute without header
350 * @skb: socket buffer to reserve room on
351 * @attrlen: length of attribute payload
352 *
353 * Reserves room for attribute payload without a header.
354 *
355 * The caller is responsible to ensure that the skb provides enough
356 * tailroom for the payload.
357 */
358void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
359{
360 void *start;
361
362 start = skb_put(skb, NLA_ALIGN(attrlen));
363 memset(start, 0, NLA_ALIGN(attrlen));
364
365 return start;
366}
367EXPORT_SYMBOL(__nla_reserve_nohdr);
368
369/**
370 * nla_reserve - reserve room for attribute on the skb
371 * @skb: socket buffer to reserve room on
372 * @attrtype: attribute type
373 * @attrlen: length of attribute payload
374 *
375 * Adds a netlink attribute header to a socket buffer and reserves
376 * room for the payload but does not copy it.
377 *
378 * Returns NULL if the tailroom of the skb is insufficient to store
379 * the attribute header and payload.
380 */
381struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
382{
383 if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
384 return NULL;
385
386 return __nla_reserve(skb, attrtype, attrlen);
387}
388EXPORT_SYMBOL(nla_reserve);
389
390/**
391 * nla_reserve_nohdr - reserve room for attribute without header
392 * @skb: socket buffer to reserve room on
393 * @attrlen: length of attribute payload
394 *
395 * Reserves room for attribute payload without a header.
396 *
397 * Returns NULL if the tailroom of the skb is insufficient to store
398 * the attribute payload.
399 */
400void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
401{
402 if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
403 return NULL;
404
405 return __nla_reserve_nohdr(skb, attrlen);
406}
407EXPORT_SYMBOL(nla_reserve_nohdr);
408
409/**
410 * __nla_put - Add a netlink attribute to a socket buffer
411 * @skb: socket buffer to add attribute to
412 * @attrtype: attribute type
413 * @attrlen: length of attribute payload
414 * @data: head of attribute payload
415 *
416 * The caller is responsible to ensure that the skb provides enough
417 * tailroom for the attribute header and payload.
418 */
419void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
420 const void *data)
421{
422 struct nlattr *nla;
423
424 nla = __nla_reserve(skb, attrtype, attrlen);
425 memcpy(nla_data(nla), data, attrlen);
426}
427EXPORT_SYMBOL(__nla_put);
428
429/**
430 * __nla_put_nohdr - Add a netlink attribute without header
431 * @skb: socket buffer to add attribute to
432 * @attrlen: length of attribute payload
433 * @data: head of attribute payload
434 *
435 * The caller is responsible to ensure that the skb provides enough
436 * tailroom for the attribute payload.
437 */
438void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
439{
440 void *start;
441
442 start = __nla_reserve_nohdr(skb, attrlen);
443 memcpy(start, data, attrlen);
444}
445EXPORT_SYMBOL(__nla_put_nohdr);
446
447/**
448 * nla_put - Add a netlink attribute to a socket buffer
449 * @skb: socket buffer to add attribute to
450 * @attrtype: attribute type
451 * @attrlen: length of attribute payload
452 * @data: head of attribute payload
453 *
454 * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
455 * the attribute header and payload.
456 */
457int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
458{
459 if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
460 return -EMSGSIZE;
461
462 __nla_put(skb, attrtype, attrlen, data);
463 return 0;
464}
465EXPORT_SYMBOL(nla_put);
466
467/**
468 * nla_put_nohdr - Add a netlink attribute without header
469 * @skb: socket buffer to add attribute to
470 * @attrlen: length of attribute payload
471 * @data: head of attribute payload
472 *
473 * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
474 * the attribute payload.
475 */
476int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
477{
478 if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
479 return -EMSGSIZE;
480
481 __nla_put_nohdr(skb, attrlen, data);
482 return 0;
483}
484EXPORT_SYMBOL(nla_put_nohdr);
485
486/**
487 * nla_append - Add a netlink attribute without header or padding
488 * @skb: socket buffer to add attribute to
489 * @attrlen: length of attribute payload
490 * @data: head of attribute payload
491 *
492 * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
493 * the attribute payload.
494 */
495int nla_append(struct sk_buff *skb, int attrlen, const void *data)
496{
497 if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
498 return -EMSGSIZE;
499
500 memcpy(skb_put(skb, attrlen), data, attrlen);
501 return 0;
502}
503EXPORT_SYMBOL(nla_append);
504#endif
505
506EXPORT_SYMBOL(nla_validate);
507EXPORT_SYMBOL(nla_policy_len);
508EXPORT_SYMBOL(nla_parse);
509EXPORT_SYMBOL(nla_find);
510EXPORT_SYMBOL(nla_strlcpy);
511EXPORT_SYMBOL(nla_memcpy);
512EXPORT_SYMBOL(nla_memcmp);
513EXPORT_SYMBOL(nla_strcmp);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * NETLINK Netlink attributes
4 *
5 * Authors: Thomas Graf <tgraf@suug.ch>
6 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
7 */
8
9#include <linux/export.h>
10#include <linux/kernel.h>
11#include <linux/errno.h>
12#include <linux/jiffies.h>
13#include <linux/nospec.h>
14#include <linux/skbuff.h>
15#include <linux/string.h>
16#include <linux/types.h>
17#include <net/netlink.h>
18
19/* For these data types, attribute length should be exactly the given
20 * size. However, to maintain compatibility with broken commands, if the
21 * attribute length does not match the expected size a warning is emitted
22 * to the user that the command is sending invalid data and needs to be fixed.
23 */
24static const u8 nla_attr_len[NLA_TYPE_MAX+1] = {
25 [NLA_U8] = sizeof(u8),
26 [NLA_U16] = sizeof(u16),
27 [NLA_U32] = sizeof(u32),
28 [NLA_U64] = sizeof(u64),
29 [NLA_S8] = sizeof(s8),
30 [NLA_S16] = sizeof(s16),
31 [NLA_S32] = sizeof(s32),
32 [NLA_S64] = sizeof(s64),
33};
34
35static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = {
36 [NLA_U8] = sizeof(u8),
37 [NLA_U16] = sizeof(u16),
38 [NLA_U32] = sizeof(u32),
39 [NLA_U64] = sizeof(u64),
40 [NLA_MSECS] = sizeof(u64),
41 [NLA_NESTED] = NLA_HDRLEN,
42 [NLA_S8] = sizeof(s8),
43 [NLA_S16] = sizeof(s16),
44 [NLA_S32] = sizeof(s32),
45 [NLA_S64] = sizeof(s64),
46};
47
48/*
49 * Nested policies might refer back to the original
50 * policy in some cases, and userspace could try to
51 * abuse that and recurse by nesting in the right
52 * ways. Limit recursion to avoid this problem.
53 */
54#define MAX_POLICY_RECURSION_DEPTH 10
55
56static int __nla_validate_parse(const struct nlattr *head, int len, int maxtype,
57 const struct nla_policy *policy,
58 unsigned int validate,
59 struct netlink_ext_ack *extack,
60 struct nlattr **tb, unsigned int depth);
61
62static int validate_nla_bitfield32(const struct nlattr *nla,
63 const u32 valid_flags_mask)
64{
65 const struct nla_bitfield32 *bf = nla_data(nla);
66
67 if (!valid_flags_mask)
68 return -EINVAL;
69
70 /*disallow invalid bit selector */
71 if (bf->selector & ~valid_flags_mask)
72 return -EINVAL;
73
74 /*disallow invalid bit values */
75 if (bf->value & ~valid_flags_mask)
76 return -EINVAL;
77
78 /*disallow valid bit values that are not selected*/
79 if (bf->value & ~bf->selector)
80 return -EINVAL;
81
82 return 0;
83}
84
85static int nla_validate_array(const struct nlattr *head, int len, int maxtype,
86 const struct nla_policy *policy,
87 struct netlink_ext_ack *extack,
88 unsigned int validate, unsigned int depth)
89{
90 const struct nlattr *entry;
91 int rem;
92
93 nla_for_each_attr(entry, head, len, rem) {
94 int ret;
95
96 if (nla_len(entry) == 0)
97 continue;
98
99 if (nla_len(entry) < NLA_HDRLEN) {
100 NL_SET_ERR_MSG_ATTR_POL(extack, entry, policy,
101 "Array element too short");
102 return -ERANGE;
103 }
104
105 ret = __nla_validate_parse(nla_data(entry), nla_len(entry),
106 maxtype, policy, validate, extack,
107 NULL, depth + 1);
108 if (ret < 0)
109 return ret;
110 }
111
112 return 0;
113}
114
115void nla_get_range_unsigned(const struct nla_policy *pt,
116 struct netlink_range_validation *range)
117{
118 WARN_ON_ONCE(pt->validation_type != NLA_VALIDATE_RANGE_PTR &&
119 (pt->min < 0 || pt->max < 0));
120
121 range->min = 0;
122
123 switch (pt->type) {
124 case NLA_U8:
125 range->max = U8_MAX;
126 break;
127 case NLA_U16:
128 case NLA_BE16:
129 case NLA_BINARY:
130 range->max = U16_MAX;
131 break;
132 case NLA_U32:
133 case NLA_BE32:
134 range->max = U32_MAX;
135 break;
136 case NLA_U64:
137 case NLA_MSECS:
138 range->max = U64_MAX;
139 break;
140 default:
141 WARN_ON_ONCE(1);
142 return;
143 }
144
145 switch (pt->validation_type) {
146 case NLA_VALIDATE_RANGE:
147 case NLA_VALIDATE_RANGE_WARN_TOO_LONG:
148 range->min = pt->min;
149 range->max = pt->max;
150 break;
151 case NLA_VALIDATE_RANGE_PTR:
152 *range = *pt->range;
153 break;
154 case NLA_VALIDATE_MIN:
155 range->min = pt->min;
156 break;
157 case NLA_VALIDATE_MAX:
158 range->max = pt->max;
159 break;
160 default:
161 break;
162 }
163}
164
165static int nla_validate_range_unsigned(const struct nla_policy *pt,
166 const struct nlattr *nla,
167 struct netlink_ext_ack *extack,
168 unsigned int validate)
169{
170 struct netlink_range_validation range;
171 u64 value;
172
173 switch (pt->type) {
174 case NLA_U8:
175 value = nla_get_u8(nla);
176 break;
177 case NLA_U16:
178 value = nla_get_u16(nla);
179 break;
180 case NLA_U32:
181 value = nla_get_u32(nla);
182 break;
183 case NLA_U64:
184 value = nla_get_u64(nla);
185 break;
186 case NLA_MSECS:
187 value = nla_get_u64(nla);
188 break;
189 case NLA_BINARY:
190 value = nla_len(nla);
191 break;
192 case NLA_BE16:
193 value = ntohs(nla_get_be16(nla));
194 break;
195 case NLA_BE32:
196 value = ntohl(nla_get_be32(nla));
197 break;
198 default:
199 return -EINVAL;
200 }
201
202 nla_get_range_unsigned(pt, &range);
203
204 if (pt->validation_type == NLA_VALIDATE_RANGE_WARN_TOO_LONG &&
205 pt->type == NLA_BINARY && value > range.max) {
206 pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
207 current->comm, pt->type);
208 if (validate & NL_VALIDATE_STRICT_ATTRS) {
209 NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
210 "invalid attribute length");
211 return -EINVAL;
212 }
213
214 /* this assumes min <= max (don't validate against min) */
215 return 0;
216 }
217
218 if (value < range.min || value > range.max) {
219 bool binary = pt->type == NLA_BINARY;
220
221 if (binary)
222 NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
223 "binary attribute size out of range");
224 else
225 NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
226 "integer out of range");
227
228 return -ERANGE;
229 }
230
231 return 0;
232}
233
234void nla_get_range_signed(const struct nla_policy *pt,
235 struct netlink_range_validation_signed *range)
236{
237 switch (pt->type) {
238 case NLA_S8:
239 range->min = S8_MIN;
240 range->max = S8_MAX;
241 break;
242 case NLA_S16:
243 range->min = S16_MIN;
244 range->max = S16_MAX;
245 break;
246 case NLA_S32:
247 range->min = S32_MIN;
248 range->max = S32_MAX;
249 break;
250 case NLA_S64:
251 range->min = S64_MIN;
252 range->max = S64_MAX;
253 break;
254 default:
255 WARN_ON_ONCE(1);
256 return;
257 }
258
259 switch (pt->validation_type) {
260 case NLA_VALIDATE_RANGE:
261 range->min = pt->min;
262 range->max = pt->max;
263 break;
264 case NLA_VALIDATE_RANGE_PTR:
265 *range = *pt->range_signed;
266 break;
267 case NLA_VALIDATE_MIN:
268 range->min = pt->min;
269 break;
270 case NLA_VALIDATE_MAX:
271 range->max = pt->max;
272 break;
273 default:
274 break;
275 }
276}
277
278static int nla_validate_int_range_signed(const struct nla_policy *pt,
279 const struct nlattr *nla,
280 struct netlink_ext_ack *extack)
281{
282 struct netlink_range_validation_signed range;
283 s64 value;
284
285 switch (pt->type) {
286 case NLA_S8:
287 value = nla_get_s8(nla);
288 break;
289 case NLA_S16:
290 value = nla_get_s16(nla);
291 break;
292 case NLA_S32:
293 value = nla_get_s32(nla);
294 break;
295 case NLA_S64:
296 value = nla_get_s64(nla);
297 break;
298 default:
299 return -EINVAL;
300 }
301
302 nla_get_range_signed(pt, &range);
303
304 if (value < range.min || value > range.max) {
305 NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
306 "integer out of range");
307 return -ERANGE;
308 }
309
310 return 0;
311}
312
313static int nla_validate_int_range(const struct nla_policy *pt,
314 const struct nlattr *nla,
315 struct netlink_ext_ack *extack,
316 unsigned int validate)
317{
318 switch (pt->type) {
319 case NLA_U8:
320 case NLA_U16:
321 case NLA_U32:
322 case NLA_U64:
323 case NLA_MSECS:
324 case NLA_BINARY:
325 case NLA_BE16:
326 case NLA_BE32:
327 return nla_validate_range_unsigned(pt, nla, extack, validate);
328 case NLA_S8:
329 case NLA_S16:
330 case NLA_S32:
331 case NLA_S64:
332 return nla_validate_int_range_signed(pt, nla, extack);
333 default:
334 WARN_ON(1);
335 return -EINVAL;
336 }
337}
338
339static int nla_validate_mask(const struct nla_policy *pt,
340 const struct nlattr *nla,
341 struct netlink_ext_ack *extack)
342{
343 u64 value;
344
345 switch (pt->type) {
346 case NLA_U8:
347 value = nla_get_u8(nla);
348 break;
349 case NLA_U16:
350 value = nla_get_u16(nla);
351 break;
352 case NLA_U32:
353 value = nla_get_u32(nla);
354 break;
355 case NLA_U64:
356 value = nla_get_u64(nla);
357 break;
358 default:
359 return -EINVAL;
360 }
361
362 if (value & ~(u64)pt->mask) {
363 NL_SET_ERR_MSG_ATTR(extack, nla, "reserved bit set");
364 return -EINVAL;
365 }
366
367 return 0;
368}
369
370static int validate_nla(const struct nlattr *nla, int maxtype,
371 const struct nla_policy *policy, unsigned int validate,
372 struct netlink_ext_ack *extack, unsigned int depth)
373{
374 u16 strict_start_type = policy[0].strict_start_type;
375 const struct nla_policy *pt;
376 int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla);
377 int err = -ERANGE;
378
379 if (strict_start_type && type >= strict_start_type)
380 validate |= NL_VALIDATE_STRICT;
381
382 if (type <= 0 || type > maxtype)
383 return 0;
384
385 type = array_index_nospec(type, maxtype + 1);
386 pt = &policy[type];
387
388 BUG_ON(pt->type > NLA_TYPE_MAX);
389
390 if (nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) {
391 pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
392 current->comm, type);
393 if (validate & NL_VALIDATE_STRICT_ATTRS) {
394 NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
395 "invalid attribute length");
396 return -EINVAL;
397 }
398 }
399
400 if (validate & NL_VALIDATE_NESTED) {
401 if ((pt->type == NLA_NESTED || pt->type == NLA_NESTED_ARRAY) &&
402 !(nla->nla_type & NLA_F_NESTED)) {
403 NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
404 "NLA_F_NESTED is missing");
405 return -EINVAL;
406 }
407 if (pt->type != NLA_NESTED && pt->type != NLA_NESTED_ARRAY &&
408 pt->type != NLA_UNSPEC && (nla->nla_type & NLA_F_NESTED)) {
409 NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
410 "NLA_F_NESTED not expected");
411 return -EINVAL;
412 }
413 }
414
415 switch (pt->type) {
416 case NLA_REJECT:
417 if (extack && pt->reject_message) {
418 NL_SET_BAD_ATTR(extack, nla);
419 extack->_msg = pt->reject_message;
420 return -EINVAL;
421 }
422 err = -EINVAL;
423 goto out_err;
424
425 case NLA_FLAG:
426 if (attrlen > 0)
427 goto out_err;
428 break;
429
430 case NLA_BITFIELD32:
431 if (attrlen != sizeof(struct nla_bitfield32))
432 goto out_err;
433
434 err = validate_nla_bitfield32(nla, pt->bitfield32_valid);
435 if (err)
436 goto out_err;
437 break;
438
439 case NLA_NUL_STRING:
440 if (pt->len)
441 minlen = min_t(int, attrlen, pt->len + 1);
442 else
443 minlen = attrlen;
444
445 if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) {
446 err = -EINVAL;
447 goto out_err;
448 }
449 fallthrough;
450
451 case NLA_STRING:
452 if (attrlen < 1)
453 goto out_err;
454
455 if (pt->len) {
456 char *buf = nla_data(nla);
457
458 if (buf[attrlen - 1] == '\0')
459 attrlen--;
460
461 if (attrlen > pt->len)
462 goto out_err;
463 }
464 break;
465
466 case NLA_BINARY:
467 if (pt->len && attrlen > pt->len)
468 goto out_err;
469 break;
470
471 case NLA_NESTED:
472 /* a nested attributes is allowed to be empty; if its not,
473 * it must have a size of at least NLA_HDRLEN.
474 */
475 if (attrlen == 0)
476 break;
477 if (attrlen < NLA_HDRLEN)
478 goto out_err;
479 if (pt->nested_policy) {
480 err = __nla_validate_parse(nla_data(nla), nla_len(nla),
481 pt->len, pt->nested_policy,
482 validate, extack, NULL,
483 depth + 1);
484 if (err < 0) {
485 /*
486 * return directly to preserve the inner
487 * error message/attribute pointer
488 */
489 return err;
490 }
491 }
492 break;
493 case NLA_NESTED_ARRAY:
494 /* a nested array attribute is allowed to be empty; if its not,
495 * it must have a size of at least NLA_HDRLEN.
496 */
497 if (attrlen == 0)
498 break;
499 if (attrlen < NLA_HDRLEN)
500 goto out_err;
501 if (pt->nested_policy) {
502 int err;
503
504 err = nla_validate_array(nla_data(nla), nla_len(nla),
505 pt->len, pt->nested_policy,
506 extack, validate, depth);
507 if (err < 0) {
508 /*
509 * return directly to preserve the inner
510 * error message/attribute pointer
511 */
512 return err;
513 }
514 }
515 break;
516
517 case NLA_UNSPEC:
518 if (validate & NL_VALIDATE_UNSPEC) {
519 NL_SET_ERR_MSG_ATTR(extack, nla,
520 "Unsupported attribute");
521 return -EINVAL;
522 }
523 if (attrlen < pt->len)
524 goto out_err;
525 break;
526
527 default:
528 if (pt->len)
529 minlen = pt->len;
530 else
531 minlen = nla_attr_minlen[pt->type];
532
533 if (attrlen < minlen)
534 goto out_err;
535 }
536
537 /* further validation */
538 switch (pt->validation_type) {
539 case NLA_VALIDATE_NONE:
540 /* nothing to do */
541 break;
542 case NLA_VALIDATE_RANGE_PTR:
543 case NLA_VALIDATE_RANGE:
544 case NLA_VALIDATE_RANGE_WARN_TOO_LONG:
545 case NLA_VALIDATE_MIN:
546 case NLA_VALIDATE_MAX:
547 err = nla_validate_int_range(pt, nla, extack, validate);
548 if (err)
549 return err;
550 break;
551 case NLA_VALIDATE_MASK:
552 err = nla_validate_mask(pt, nla, extack);
553 if (err)
554 return err;
555 break;
556 case NLA_VALIDATE_FUNCTION:
557 if (pt->validate) {
558 err = pt->validate(nla, extack);
559 if (err)
560 return err;
561 }
562 break;
563 }
564
565 return 0;
566out_err:
567 NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
568 "Attribute failed policy validation");
569 return err;
570}
571
572static int __nla_validate_parse(const struct nlattr *head, int len, int maxtype,
573 const struct nla_policy *policy,
574 unsigned int validate,
575 struct netlink_ext_ack *extack,
576 struct nlattr **tb, unsigned int depth)
577{
578 const struct nlattr *nla;
579 int rem;
580
581 if (depth >= MAX_POLICY_RECURSION_DEPTH) {
582 NL_SET_ERR_MSG(extack,
583 "allowed policy recursion depth exceeded");
584 return -EINVAL;
585 }
586
587 if (tb)
588 memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
589
590 nla_for_each_attr(nla, head, len, rem) {
591 u16 type = nla_type(nla);
592
593 if (type == 0 || type > maxtype) {
594 if (validate & NL_VALIDATE_MAXTYPE) {
595 NL_SET_ERR_MSG_ATTR(extack, nla,
596 "Unknown attribute type");
597 return -EINVAL;
598 }
599 continue;
600 }
601 type = array_index_nospec(type, maxtype + 1);
602 if (policy) {
603 int err = validate_nla(nla, maxtype, policy,
604 validate, extack, depth);
605
606 if (err < 0)
607 return err;
608 }
609
610 if (tb)
611 tb[type] = (struct nlattr *)nla;
612 }
613
614 if (unlikely(rem > 0)) {
615 pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n",
616 rem, current->comm);
617 NL_SET_ERR_MSG(extack, "bytes leftover after parsing attributes");
618 if (validate & NL_VALIDATE_TRAILING)
619 return -EINVAL;
620 }
621
622 return 0;
623}
624
625/**
626 * __nla_validate - Validate a stream of attributes
627 * @head: head of attribute stream
628 * @len: length of attribute stream
629 * @maxtype: maximum attribute type to be expected
630 * @policy: validation policy
631 * @validate: validation strictness
632 * @extack: extended ACK report struct
633 *
634 * Validates all attributes in the specified attribute stream against the
635 * specified policy. Validation depends on the validate flags passed, see
636 * &enum netlink_validation for more details on that.
637 * See documentation of struct nla_policy for more details.
638 *
639 * Returns 0 on success or a negative error code.
640 */
641int __nla_validate(const struct nlattr *head, int len, int maxtype,
642 const struct nla_policy *policy, unsigned int validate,
643 struct netlink_ext_ack *extack)
644{
645 return __nla_validate_parse(head, len, maxtype, policy, validate,
646 extack, NULL, 0);
647}
648EXPORT_SYMBOL(__nla_validate);
649
650/**
651 * nla_policy_len - Determine the max. length of a policy
652 * @p: policy to use
653 * @n: number of policies
654 *
655 * Determines the max. length of the policy. It is currently used
656 * to allocated Netlink buffers roughly the size of the actual
657 * message.
658 *
659 * Returns 0 on success or a negative error code.
660 */
661int
662nla_policy_len(const struct nla_policy *p, int n)
663{
664 int i, len = 0;
665
666 for (i = 0; i < n; i++, p++) {
667 if (p->len)
668 len += nla_total_size(p->len);
669 else if (nla_attr_len[p->type])
670 len += nla_total_size(nla_attr_len[p->type]);
671 else if (nla_attr_minlen[p->type])
672 len += nla_total_size(nla_attr_minlen[p->type]);
673 }
674
675 return len;
676}
677EXPORT_SYMBOL(nla_policy_len);
678
679/**
680 * __nla_parse - Parse a stream of attributes into a tb buffer
681 * @tb: destination array with maxtype+1 elements
682 * @maxtype: maximum attribute type to be expected
683 * @head: head of attribute stream
684 * @len: length of attribute stream
685 * @policy: validation policy
686 * @validate: validation strictness
687 * @extack: extended ACK pointer
688 *
689 * Parses a stream of attributes and stores a pointer to each attribute in
690 * the tb array accessible via the attribute type.
691 * Validation is controlled by the @validate parameter.
692 *
693 * Returns 0 on success or a negative error code.
694 */
695int __nla_parse(struct nlattr **tb, int maxtype,
696 const struct nlattr *head, int len,
697 const struct nla_policy *policy, unsigned int validate,
698 struct netlink_ext_ack *extack)
699{
700 return __nla_validate_parse(head, len, maxtype, policy, validate,
701 extack, tb, 0);
702}
703EXPORT_SYMBOL(__nla_parse);
704
705/**
706 * nla_find - Find a specific attribute in a stream of attributes
707 * @head: head of attribute stream
708 * @len: length of attribute stream
709 * @attrtype: type of attribute to look for
710 *
711 * Returns the first attribute in the stream matching the specified type.
712 */
713struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype)
714{
715 const struct nlattr *nla;
716 int rem;
717
718 nla_for_each_attr(nla, head, len, rem)
719 if (nla_type(nla) == attrtype)
720 return (struct nlattr *)nla;
721
722 return NULL;
723}
724EXPORT_SYMBOL(nla_find);
725
726/**
727 * nla_strscpy - Copy string attribute payload into a sized buffer
728 * @dst: Where to copy the string to.
729 * @nla: Attribute to copy the string from.
730 * @dstsize: Size of destination buffer.
731 *
732 * Copies at most dstsize - 1 bytes into the destination buffer.
733 * Unlike strlcpy the destination buffer is always padded out.
734 *
735 * Return:
736 * * srclen - Returns @nla length (not including the trailing %NUL).
737 * * -E2BIG - If @dstsize is 0 or greater than U16_MAX or @nla length greater
738 * than @dstsize.
739 */
740ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize)
741{
742 size_t srclen = nla_len(nla);
743 char *src = nla_data(nla);
744 ssize_t ret;
745 size_t len;
746
747 if (dstsize == 0 || WARN_ON_ONCE(dstsize > U16_MAX))
748 return -E2BIG;
749
750 if (srclen > 0 && src[srclen - 1] == '\0')
751 srclen--;
752
753 if (srclen >= dstsize) {
754 len = dstsize - 1;
755 ret = -E2BIG;
756 } else {
757 len = srclen;
758 ret = len;
759 }
760
761 memcpy(dst, src, len);
762 /* Zero pad end of dst. */
763 memset(dst + len, 0, dstsize - len);
764
765 return ret;
766}
767EXPORT_SYMBOL(nla_strscpy);
768
769/**
770 * nla_strdup - Copy string attribute payload into a newly allocated buffer
771 * @nla: attribute to copy the string from
772 * @flags: the type of memory to allocate (see kmalloc).
773 *
774 * Returns a pointer to the allocated buffer or NULL on error.
775 */
776char *nla_strdup(const struct nlattr *nla, gfp_t flags)
777{
778 size_t srclen = nla_len(nla);
779 char *src = nla_data(nla), *dst;
780
781 if (srclen > 0 && src[srclen - 1] == '\0')
782 srclen--;
783
784 dst = kmalloc(srclen + 1, flags);
785 if (dst != NULL) {
786 memcpy(dst, src, srclen);
787 dst[srclen] = '\0';
788 }
789 return dst;
790}
791EXPORT_SYMBOL(nla_strdup);
792
793/**
794 * nla_memcpy - Copy a netlink attribute into another memory area
795 * @dest: where to copy to memcpy
796 * @src: netlink attribute to copy from
797 * @count: size of the destination area
798 *
799 * Note: The number of bytes copied is limited by the length of
800 * attribute's payload. memcpy
801 *
802 * Returns the number of bytes copied.
803 */
804int nla_memcpy(void *dest, const struct nlattr *src, int count)
805{
806 int minlen = min_t(int, count, nla_len(src));
807
808 memcpy(dest, nla_data(src), minlen);
809 if (count > minlen)
810 memset(dest + minlen, 0, count - minlen);
811
812 return minlen;
813}
814EXPORT_SYMBOL(nla_memcpy);
815
816/**
817 * nla_memcmp - Compare an attribute with sized memory area
818 * @nla: netlink attribute
819 * @data: memory area
820 * @size: size of memory area
821 */
822int nla_memcmp(const struct nlattr *nla, const void *data,
823 size_t size)
824{
825 int d = nla_len(nla) - size;
826
827 if (d == 0)
828 d = memcmp(nla_data(nla), data, size);
829
830 return d;
831}
832EXPORT_SYMBOL(nla_memcmp);
833
834/**
835 * nla_strcmp - Compare a string attribute against a string
836 * @nla: netlink string attribute
837 * @str: another string
838 */
839int nla_strcmp(const struct nlattr *nla, const char *str)
840{
841 int len = strlen(str);
842 char *buf = nla_data(nla);
843 int attrlen = nla_len(nla);
844 int d;
845
846 while (attrlen > 0 && buf[attrlen - 1] == '\0')
847 attrlen--;
848
849 d = attrlen - len;
850 if (d == 0)
851 d = memcmp(nla_data(nla), str, len);
852
853 return d;
854}
855EXPORT_SYMBOL(nla_strcmp);
856
857#ifdef CONFIG_NET
858/**
859 * __nla_reserve - reserve room for attribute on the skb
860 * @skb: socket buffer to reserve room on
861 * @attrtype: attribute type
862 * @attrlen: length of attribute payload
863 *
864 * Adds a netlink attribute header to a socket buffer and reserves
865 * room for the payload but does not copy it.
866 *
867 * The caller is responsible to ensure that the skb provides enough
868 * tailroom for the attribute header and payload.
869 */
870struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
871{
872 struct nlattr *nla;
873
874 nla = skb_put(skb, nla_total_size(attrlen));
875 nla->nla_type = attrtype;
876 nla->nla_len = nla_attr_size(attrlen);
877
878 memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen));
879
880 return nla;
881}
882EXPORT_SYMBOL(__nla_reserve);
883
884/**
885 * __nla_reserve_64bit - reserve room for attribute on the skb and align it
886 * @skb: socket buffer to reserve room on
887 * @attrtype: attribute type
888 * @attrlen: length of attribute payload
889 * @padattr: attribute type for the padding
890 *
891 * Adds a netlink attribute header to a socket buffer and reserves
892 * room for the payload but does not copy it. It also ensure that this
893 * attribute will have a 64-bit aligned nla_data() area.
894 *
895 * The caller is responsible to ensure that the skb provides enough
896 * tailroom for the attribute header and payload.
897 */
898struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
899 int attrlen, int padattr)
900{
901 nla_align_64bit(skb, padattr);
902
903 return __nla_reserve(skb, attrtype, attrlen);
904}
905EXPORT_SYMBOL(__nla_reserve_64bit);
906
907/**
908 * __nla_reserve_nohdr - reserve room for attribute without header
909 * @skb: socket buffer to reserve room on
910 * @attrlen: length of attribute payload
911 *
912 * Reserves room for attribute payload without a header.
913 *
914 * The caller is responsible to ensure that the skb provides enough
915 * tailroom for the payload.
916 */
917void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
918{
919 return skb_put_zero(skb, NLA_ALIGN(attrlen));
920}
921EXPORT_SYMBOL(__nla_reserve_nohdr);
922
923/**
924 * nla_reserve - reserve room for attribute on the skb
925 * @skb: socket buffer to reserve room on
926 * @attrtype: attribute type
927 * @attrlen: length of attribute payload
928 *
929 * Adds a netlink attribute header to a socket buffer and reserves
930 * room for the payload but does not copy it.
931 *
932 * Returns NULL if the tailroom of the skb is insufficient to store
933 * the attribute header and payload.
934 */
935struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
936{
937 if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
938 return NULL;
939
940 return __nla_reserve(skb, attrtype, attrlen);
941}
942EXPORT_SYMBOL(nla_reserve);
943
944/**
945 * nla_reserve_64bit - reserve room for attribute on the skb and align it
946 * @skb: socket buffer to reserve room on
947 * @attrtype: attribute type
948 * @attrlen: length of attribute payload
949 * @padattr: attribute type for the padding
950 *
951 * Adds a netlink attribute header to a socket buffer and reserves
952 * room for the payload but does not copy it. It also ensure that this
953 * attribute will have a 64-bit aligned nla_data() area.
954 *
955 * Returns NULL if the tailroom of the skb is insufficient to store
956 * the attribute header and payload.
957 */
958struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, int attrlen,
959 int padattr)
960{
961 size_t len;
962
963 if (nla_need_padding_for_64bit(skb))
964 len = nla_total_size_64bit(attrlen);
965 else
966 len = nla_total_size(attrlen);
967 if (unlikely(skb_tailroom(skb) < len))
968 return NULL;
969
970 return __nla_reserve_64bit(skb, attrtype, attrlen, padattr);
971}
972EXPORT_SYMBOL(nla_reserve_64bit);
973
974/**
975 * nla_reserve_nohdr - reserve room for attribute without header
976 * @skb: socket buffer to reserve room on
977 * @attrlen: length of attribute payload
978 *
979 * Reserves room for attribute payload without a header.
980 *
981 * Returns NULL if the tailroom of the skb is insufficient to store
982 * the attribute payload.
983 */
984void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
985{
986 if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
987 return NULL;
988
989 return __nla_reserve_nohdr(skb, attrlen);
990}
991EXPORT_SYMBOL(nla_reserve_nohdr);
992
993/**
994 * __nla_put - Add a netlink attribute to a socket buffer
995 * @skb: socket buffer to add attribute to
996 * @attrtype: attribute type
997 * @attrlen: length of attribute payload
998 * @data: head of attribute payload
999 *
1000 * The caller is responsible to ensure that the skb provides enough
1001 * tailroom for the attribute header and payload.
1002 */
1003void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
1004 const void *data)
1005{
1006 struct nlattr *nla;
1007
1008 nla = __nla_reserve(skb, attrtype, attrlen);
1009 memcpy(nla_data(nla), data, attrlen);
1010}
1011EXPORT_SYMBOL(__nla_put);
1012
1013/**
1014 * __nla_put_64bit - Add a netlink attribute to a socket buffer and align it
1015 * @skb: socket buffer to add attribute to
1016 * @attrtype: attribute type
1017 * @attrlen: length of attribute payload
1018 * @data: head of attribute payload
1019 * @padattr: attribute type for the padding
1020 *
1021 * The caller is responsible to ensure that the skb provides enough
1022 * tailroom for the attribute header and payload.
1023 */
1024void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
1025 const void *data, int padattr)
1026{
1027 struct nlattr *nla;
1028
1029 nla = __nla_reserve_64bit(skb, attrtype, attrlen, padattr);
1030 memcpy(nla_data(nla), data, attrlen);
1031}
1032EXPORT_SYMBOL(__nla_put_64bit);
1033
1034/**
1035 * __nla_put_nohdr - Add a netlink attribute without header
1036 * @skb: socket buffer to add attribute to
1037 * @attrlen: length of attribute payload
1038 * @data: head of attribute payload
1039 *
1040 * The caller is responsible to ensure that the skb provides enough
1041 * tailroom for the attribute payload.
1042 */
1043void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
1044{
1045 void *start;
1046
1047 start = __nla_reserve_nohdr(skb, attrlen);
1048 memcpy(start, data, attrlen);
1049}
1050EXPORT_SYMBOL(__nla_put_nohdr);
1051
1052/**
1053 * nla_put - Add a netlink attribute to a socket buffer
1054 * @skb: socket buffer to add attribute to
1055 * @attrtype: attribute type
1056 * @attrlen: length of attribute payload
1057 * @data: head of attribute payload
1058 *
1059 * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
1060 * the attribute header and payload.
1061 */
1062int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
1063{
1064 if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
1065 return -EMSGSIZE;
1066
1067 __nla_put(skb, attrtype, attrlen, data);
1068 return 0;
1069}
1070EXPORT_SYMBOL(nla_put);
1071
1072/**
1073 * nla_put_64bit - Add a netlink attribute to a socket buffer and align it
1074 * @skb: socket buffer to add attribute to
1075 * @attrtype: attribute type
1076 * @attrlen: length of attribute payload
1077 * @data: head of attribute payload
1078 * @padattr: attribute type for the padding
1079 *
1080 * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
1081 * the attribute header and payload.
1082 */
1083int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
1084 const void *data, int padattr)
1085{
1086 size_t len;
1087
1088 if (nla_need_padding_for_64bit(skb))
1089 len = nla_total_size_64bit(attrlen);
1090 else
1091 len = nla_total_size(attrlen);
1092 if (unlikely(skb_tailroom(skb) < len))
1093 return -EMSGSIZE;
1094
1095 __nla_put_64bit(skb, attrtype, attrlen, data, padattr);
1096 return 0;
1097}
1098EXPORT_SYMBOL(nla_put_64bit);
1099
1100/**
1101 * nla_put_nohdr - Add a netlink attribute without header
1102 * @skb: socket buffer to add attribute to
1103 * @attrlen: length of attribute payload
1104 * @data: head of attribute payload
1105 *
1106 * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
1107 * the attribute payload.
1108 */
1109int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
1110{
1111 if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
1112 return -EMSGSIZE;
1113
1114 __nla_put_nohdr(skb, attrlen, data);
1115 return 0;
1116}
1117EXPORT_SYMBOL(nla_put_nohdr);
1118
1119/**
1120 * nla_append - Add a netlink attribute without header or padding
1121 * @skb: socket buffer to add attribute to
1122 * @attrlen: length of attribute payload
1123 * @data: head of attribute payload
1124 *
1125 * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
1126 * the attribute payload.
1127 */
1128int nla_append(struct sk_buff *skb, int attrlen, const void *data)
1129{
1130 if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
1131 return -EMSGSIZE;
1132
1133 skb_put_data(skb, data, attrlen);
1134 return 0;
1135}
1136EXPORT_SYMBOL(nla_append);
1137#endif