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