1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __NET_NETLINK_H
3 #define __NET_NETLINK_H
4
5 #include <linux/types.h>
6 #include <linux/netlink.h>
7 #include <linux/jiffies.h>
8 #include <linux/in6.h>
9
10 /* ========================================================================
11 * Netlink Messages and Attributes Interface (As Seen On TV)
12 * ------------------------------------------------------------------------
13 * Messages Interface
14 * ------------------------------------------------------------------------
15 *
16 * Message Format:
17 * <--- nlmsg_total_size(payload) --->
18 * <-- nlmsg_msg_size(payload) ->
19 * +----------+- - -+-------------+- - -+-------- - -
20 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr
21 * +----------+- - -+-------------+- - -+-------- - -
22 * nlmsg_data(nlh)---^ ^
23 * nlmsg_next(nlh)-----------------------+
24 *
25 * Payload Format:
26 * <---------------------- nlmsg_len(nlh) --------------------->
27 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
28 * +----------------------+- - -+--------------------------------+
29 * | Family Header | Pad | Attributes |
30 * +----------------------+- - -+--------------------------------+
31 * nlmsg_attrdata(nlh, hdrlen)---^
32 *
33 * Data Structures:
34 * struct nlmsghdr netlink message header
35 *
36 * Message Construction:
37 * nlmsg_new() create a new netlink message
38 * nlmsg_put() add a netlink message to an skb
39 * nlmsg_put_answer() callback based nlmsg_put()
40 * nlmsg_end() finalize netlink message
41 * nlmsg_get_pos() return current position in message
42 * nlmsg_trim() trim part of message
43 * nlmsg_cancel() cancel message construction
44 * nlmsg_consume() free a netlink message (expected)
45 * nlmsg_free() free a netlink message (drop)
46 *
47 * Message Sending:
48 * nlmsg_multicast() multicast message to several groups
49 * nlmsg_unicast() unicast a message to a single socket
50 * nlmsg_notify() send notification message
51 *
52 * Message Length Calculations:
53 * nlmsg_msg_size(payload) length of message w/o padding
54 * nlmsg_total_size(payload) length of message w/ padding
55 * nlmsg_padlen(payload) length of padding at tail
56 *
57 * Message Payload Access:
58 * nlmsg_data(nlh) head of message payload
59 * nlmsg_len(nlh) length of message payload
60 * nlmsg_attrdata(nlh, hdrlen) head of attributes data
61 * nlmsg_attrlen(nlh, hdrlen) length of attributes data
62 *
63 * Message Parsing:
64 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
65 * nlmsg_next(nlh, remaining) get next netlink message
66 * nlmsg_parse() parse attributes of a message
67 * nlmsg_find_attr() find an attribute in a message
68 * nlmsg_for_each_msg() loop over all messages
69 * nlmsg_validate() validate netlink message incl. attrs
70 * nlmsg_for_each_attr() loop over all attributes
71 *
72 * Misc:
73 * nlmsg_report() report back to application?
74 *
75 * ------------------------------------------------------------------------
76 * Attributes Interface
77 * ------------------------------------------------------------------------
78 *
79 * Attribute Format:
80 * <------- nla_total_size(payload) ------->
81 * <---- nla_attr_size(payload) ----->
82 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
83 * | Header | Pad | Payload | Pad | Header
84 * +----------+- - -+- - - - - - - - - +- - -+-------- - -
85 * <- nla_len(nla) -> ^
86 * nla_data(nla)----^ |
87 * nla_next(nla)-----------------------------'
88 *
89 * Data Structures:
90 * struct nlattr netlink attribute header
91 *
92 * Attribute Construction:
93 * nla_reserve(skb, type, len) reserve room for an attribute
94 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
95 * nla_put(skb, type, len, data) add attribute to skb
96 * nla_put_nohdr(skb, len, data) add attribute w/o hdr
97 * nla_append(skb, len, data) append data to skb
98 *
99 * Attribute Construction for Basic Types:
100 * nla_put_u8(skb, type, value) add u8 attribute to skb
101 * nla_put_u16(skb, type, value) add u16 attribute to skb
102 * nla_put_u32(skb, type, value) add u32 attribute to skb
103 * nla_put_u64_64bit(skb, type,
104 * value, padattr) add u64 attribute to skb
105 * nla_put_s8(skb, type, value) add s8 attribute to skb
106 * nla_put_s16(skb, type, value) add s16 attribute to skb
107 * nla_put_s32(skb, type, value) add s32 attribute to skb
108 * nla_put_s64(skb, type, value,
109 * padattr) add s64 attribute to skb
110 * nla_put_string(skb, type, str) add string attribute to skb
111 * nla_put_flag(skb, type) add flag attribute to skb
112 * nla_put_msecs(skb, type, jiffies,
113 * padattr) add msecs attribute to skb
114 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb
115 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb
116 *
117 * Nested Attributes Construction:
118 * nla_nest_start(skb, type) start a nested attribute
119 * nla_nest_end(skb, nla) finalize a nested attribute
120 * nla_nest_cancel(skb, nla) cancel nested attribute construction
121 *
122 * Attribute Length Calculations:
123 * nla_attr_size(payload) length of attribute w/o padding
124 * nla_total_size(payload) length of attribute w/ padding
125 * nla_padlen(payload) length of padding
126 *
127 * Attribute Payload Access:
128 * nla_data(nla) head of attribute payload
129 * nla_len(nla) length of attribute payload
130 *
131 * Attribute Payload Access for Basic Types:
132 * nla_get_uint(nla) get payload for a uint attribute
133 * nla_get_sint(nla) get payload for a sint attribute
134 * nla_get_u8(nla) get payload for a u8 attribute
135 * nla_get_u16(nla) get payload for a u16 attribute
136 * nla_get_u32(nla) get payload for a u32 attribute
137 * nla_get_u64(nla) get payload for a u64 attribute
138 * nla_get_s8(nla) get payload for a s8 attribute
139 * nla_get_s16(nla) get payload for a s16 attribute
140 * nla_get_s32(nla) get payload for a s32 attribute
141 * nla_get_s64(nla) get payload for a s64 attribute
142 * nla_get_flag(nla) return 1 if flag is true
143 * nla_get_msecs(nla) get payload for a msecs attribute
144 *
145 * Attribute Misc:
146 * nla_memcpy(dest, nla, count) copy attribute into memory
147 * nla_memcmp(nla, data, size) compare attribute with memory area
148 * nla_strscpy(dst, nla, size) copy attribute to a sized string
149 * nla_strcmp(nla, str) compare attribute with string
150 *
151 * Attribute Parsing:
152 * nla_ok(nla, remaining) does nla fit into remaining bytes?
153 * nla_next(nla, remaining) get next netlink attribute
154 * nla_validate() validate a stream of attributes
155 * nla_validate_nested() validate a stream of nested attributes
156 * nla_find() find attribute in stream of attributes
157 * nla_find_nested() find attribute in nested attributes
158 * nla_parse() parse and validate stream of attrs
159 * nla_parse_nested() parse nested attributes
160 * nla_for_each_attr() loop over all attributes
161 * nla_for_each_attr_type() loop over all attributes with the
162 * given type
163 * nla_for_each_nested() loop over the nested attributes
164 * nla_for_each_nested_type() loop over the nested attributes with
165 * the given type
166 *=========================================================================
167 */
168
169 /**
170 * Standard attribute types to specify validation policy
171 */
172 enum {
173 NLA_UNSPEC,
174 NLA_U8,
175 NLA_U16,
176 NLA_U32,
177 NLA_U64,
178 NLA_STRING,
179 NLA_FLAG,
180 NLA_MSECS,
181 NLA_NESTED,
182 NLA_NESTED_ARRAY,
183 NLA_NUL_STRING,
184 NLA_BINARY,
185 NLA_S8,
186 NLA_S16,
187 NLA_S32,
188 NLA_S64,
189 NLA_BITFIELD32,
190 NLA_REJECT,
191 NLA_BE16,
192 NLA_BE32,
193 NLA_SINT,
194 NLA_UINT,
195 __NLA_TYPE_MAX,
196 };
197
198 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
199
200 struct netlink_range_validation {
201 u64 min, max;
202 };
203
204 struct netlink_range_validation_signed {
205 s64 min, max;
206 };
207
208 enum nla_policy_validation {
209 NLA_VALIDATE_NONE,
210 NLA_VALIDATE_RANGE,
211 NLA_VALIDATE_RANGE_WARN_TOO_LONG,
212 NLA_VALIDATE_MIN,
213 NLA_VALIDATE_MAX,
214 NLA_VALIDATE_MASK,
215 NLA_VALIDATE_RANGE_PTR,
216 NLA_VALIDATE_FUNCTION,
217 };
218
219 /**
220 * struct nla_policy - attribute validation policy
221 * @type: Type of attribute or NLA_UNSPEC
222 * @validation_type: type of attribute validation done in addition to
223 * type-specific validation (e.g. range, function call), see
224 * &enum nla_policy_validation
225 * @len: Type specific length of payload
226 *
227 * Policies are defined as arrays of this struct, the array must be
228 * accessible by attribute type up to the highest identifier to be expected.
229 *
230 * Meaning of `len' field:
231 * NLA_STRING Maximum length of string
232 * NLA_NUL_STRING Maximum length of string (excluding NUL)
233 * NLA_FLAG Unused
234 * NLA_BINARY Maximum length of attribute payload
235 * (but see also below with the validation type)
236 * NLA_NESTED,
237 * NLA_NESTED_ARRAY Length verification is done by checking len of
238 * nested header (or empty); len field is used if
239 * nested_policy is also used, for the max attr
240 * number in the nested policy.
241 * NLA_SINT, NLA_UINT,
242 * NLA_U8, NLA_U16,
243 * NLA_U32, NLA_U64,
244 * NLA_S8, NLA_S16,
245 * NLA_S32, NLA_S64,
246 * NLA_BE16, NLA_BE32,
247 * NLA_MSECS Leaving the length field zero will verify the
248 * given type fits, using it verifies minimum length
249 * just like "All other"
250 * NLA_BITFIELD32 Unused
251 * NLA_REJECT Unused
252 * All other Minimum length of attribute payload
253 *
254 * Meaning of validation union:
255 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and
256 * `bitfield32_valid' is the u32 value of valid flags
257 * NLA_REJECT This attribute is always rejected and `reject_message'
258 * may point to a string to report as the error instead
259 * of the generic one in extended ACK.
260 * NLA_NESTED `nested_policy' to a nested policy to validate, must
261 * also set `len' to the max attribute number. Use the
262 * provided NLA_POLICY_NESTED() macro.
263 * Note that nla_parse() will validate, but of course not
264 * parse, the nested sub-policies.
265 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate,
266 * must also set `len' to the max attribute number. Use
267 * the provided NLA_POLICY_NESTED_ARRAY() macro.
268 * The difference to NLA_NESTED is the structure:
269 * NLA_NESTED has the nested attributes directly inside
270 * while an array has the nested attributes at another
271 * level down and the attribute types directly in the
272 * nesting don't matter.
273 * NLA_UINT,
274 * NLA_U8,
275 * NLA_U16,
276 * NLA_U32,
277 * NLA_U64,
278 * NLA_BE16,
279 * NLA_BE32,
280 * NLA_SINT,
281 * NLA_S8,
282 * NLA_S16,
283 * NLA_S32,
284 * NLA_S64 The `min' and `max' fields are used depending on the
285 * validation_type field, if that is min/max/range then
286 * the min, max or both are used (respectively) to check
287 * the value of the integer attribute.
288 * Note that in the interest of code simplicity and
289 * struct size both limits are s16, so you cannot
290 * enforce a range that doesn't fall within the range
291 * of s16 - do that using the NLA_POLICY_FULL_RANGE()
292 * or NLA_POLICY_FULL_RANGE_SIGNED() macros instead.
293 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
294 * NLA_POLICY_RANGE() macros.
295 * NLA_UINT,
296 * NLA_U8,
297 * NLA_U16,
298 * NLA_U32,
299 * NLA_U64 If the validation_type field instead is set to
300 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
301 * to a struct netlink_range_validation that indicates
302 * the min/max values.
303 * Use NLA_POLICY_FULL_RANGE().
304 * NLA_SINT,
305 * NLA_S8,
306 * NLA_S16,
307 * NLA_S32,
308 * NLA_S64 If the validation_type field instead is set to
309 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
310 * pointer to a struct netlink_range_validation_signed
311 * that indicates the min/max values.
312 * Use NLA_POLICY_FULL_RANGE_SIGNED().
313 *
314 * NLA_BINARY If the validation type is like the ones for integers
315 * above, then the min/max length (not value like for
316 * integers) of the attribute is enforced.
317 *
318 * All other Unused - but note that it's a union
319 *
320 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
321 * NLA_BINARY Validation function called for the attribute.
322 * All other Unused - but note that it's a union
323 *
324 * Example:
325 *
326 * static const u32 myvalidflags = 0xff231023;
327 *
328 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
329 * [ATTR_FOO] = { .type = NLA_U16 },
330 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
331 * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)),
332 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
333 * };
334 */
335 struct nla_policy {
336 u8 type;
337 u8 validation_type;
338 u16 len;
339 union {
340 /**
341 * @strict_start_type: first attribute to validate strictly
342 *
343 * This entry is special, and used for the attribute at index 0
344 * only, and specifies special data about the policy, namely it
345 * specifies the "boundary type" where strict length validation
346 * starts for any attribute types >= this value, also, strict
347 * nesting validation starts here.
348 *
349 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
350 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to
351 * get the previous pure { .len = xyz } behaviour. The advantage
352 * of this is that types not specified in the policy will be
353 * rejected.
354 *
355 * For completely new families it should be set to 1 so that the
356 * validation is enforced for all attributes. For existing ones
357 * it should be set at least when new attributes are added to
358 * the enum used by the policy, and be set to the new value that
359 * was added to enforce strict validation from thereon.
360 */
361 u16 strict_start_type;
362
363 /* private: use NLA_POLICY_*() to set */
364 const u32 bitfield32_valid;
365 const u32 mask;
366 const char *reject_message;
367 const struct nla_policy *nested_policy;
368 const struct netlink_range_validation *range;
369 const struct netlink_range_validation_signed *range_signed;
370 struct {
371 s16 min, max;
372 };
373 int (*validate)(const struct nlattr *attr,
374 struct netlink_ext_ack *extack);
375 };
376 };
377
378 #define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN)
379 #define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
380
381 #define _NLA_POLICY_NESTED(maxattr, policy) \
382 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
383 #define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
384 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
385 #define NLA_POLICY_NESTED(policy) \
386 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
387 #define NLA_POLICY_NESTED_ARRAY(policy) \
388 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
389 #define NLA_POLICY_BITFIELD32(valid) \
390 { .type = NLA_BITFIELD32, .bitfield32_valid = valid }
391
392 #define __NLA_IS_UINT_TYPE(tp) \
393 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || \
394 tp == NLA_U64 || tp == NLA_UINT || \
395 tp == NLA_BE16 || tp == NLA_BE32)
396 #define __NLA_IS_SINT_TYPE(tp) \
397 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64 || \
398 tp == NLA_SINT)
399
400 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
401 #define NLA_ENSURE_UINT_TYPE(tp) \
402 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
403 #define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \
404 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
405 tp == NLA_MSECS || \
406 tp == NLA_BINARY) + tp)
407 #define NLA_ENSURE_SINT_TYPE(tp) \
408 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
409 #define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \
410 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
411 __NLA_IS_SINT_TYPE(tp) || \
412 tp == NLA_MSECS || \
413 tp == NLA_BINARY) + tp)
414 #define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
415 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \
416 tp != NLA_REJECT && \
417 tp != NLA_NESTED && \
418 tp != NLA_NESTED_ARRAY) + tp)
419
420 #define NLA_POLICY_RANGE(tp, _min, _max) { \
421 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
422 .validation_type = NLA_VALIDATE_RANGE, \
423 .min = _min, \
424 .max = _max \
425 }
426
427 #define NLA_POLICY_FULL_RANGE(tp, _range) { \
428 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \
429 .validation_type = NLA_VALIDATE_RANGE_PTR, \
430 .range = _range, \
431 }
432
433 #define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \
434 .type = NLA_ENSURE_SINT_TYPE(tp), \
435 .validation_type = NLA_VALIDATE_RANGE_PTR, \
436 .range_signed = _range, \
437 }
438
439 #define NLA_POLICY_MIN(tp, _min) { \
440 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
441 .validation_type = NLA_VALIDATE_MIN, \
442 .min = _min, \
443 }
444
445 #define NLA_POLICY_MAX(tp, _max) { \
446 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
447 .validation_type = NLA_VALIDATE_MAX, \
448 .max = _max, \
449 }
450
451 #define NLA_POLICY_MASK(tp, _mask) { \
452 .type = NLA_ENSURE_UINT_TYPE(tp), \
453 .validation_type = NLA_VALIDATE_MASK, \
454 .mask = _mask, \
455 }
456
457 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \
458 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \
459 .validation_type = NLA_VALIDATE_FUNCTION, \
460 .validate = fn, \
461 .len = __VA_ARGS__ + 0, \
462 }
463
464 #define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
465 #define NLA_POLICY_EXACT_LEN_WARN(_len) { \
466 .type = NLA_BINARY, \
467 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \
468 .min = _len, \
469 .max = _len \
470 }
471 #define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len)
472
473 /**
474 * struct nl_info - netlink source information
475 * @nlh: Netlink message header of original request
476 * @nl_net: Network namespace
477 * @portid: Netlink PORTID of requesting application
478 * @skip_notify: Skip netlink notifications to user space
479 * @skip_notify_kernel: Skip selected in-kernel notifications
480 */
481 struct nl_info {
482 struct nlmsghdr *nlh;
483 struct net *nl_net;
484 u32 portid;
485 u8 skip_notify:1,
486 skip_notify_kernel:1;
487 };
488
489 /**
490 * enum netlink_validation - netlink message/attribute validation levels
491 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
492 * extra data at the end of the message, attributes being longer than
493 * they should be, or unknown attributes being present.
494 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
495 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
496 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
497 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
498 * This can safely be set by the kernel when the given policy has no
499 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
500 * are enforced going forward.
501 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
502 * U8, U16, U32 must have exact size, etc.)
503 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
504 * and unset for other policies.
505 */
506 enum netlink_validation {
507 NL_VALIDATE_LIBERAL = 0,
508 NL_VALIDATE_TRAILING = BIT(0),
509 NL_VALIDATE_MAXTYPE = BIT(1),
510 NL_VALIDATE_UNSPEC = BIT(2),
511 NL_VALIDATE_STRICT_ATTRS = BIT(3),
512 NL_VALIDATE_NESTED = BIT(4),
513 };
514
515 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
516 NL_VALIDATE_MAXTYPE)
517 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
518 NL_VALIDATE_MAXTYPE |\
519 NL_VALIDATE_UNSPEC |\
520 NL_VALIDATE_STRICT_ATTRS |\
521 NL_VALIDATE_NESTED)
522
523 int netlink_rcv_skb(struct sk_buff *skb,
524 int (*cb)(struct sk_buff *, struct nlmsghdr *,
525 struct netlink_ext_ack *));
526 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
527 unsigned int group, int report, gfp_t flags);
528
529 int __nla_validate(const struct nlattr *head, int len, int maxtype,
530 const struct nla_policy *policy, unsigned int validate,
531 struct netlink_ext_ack *extack);
532 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
533 int len, const struct nla_policy *policy, unsigned int validate,
534 struct netlink_ext_ack *extack);
535 int nla_policy_len(const struct nla_policy *, int);
536 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
537 ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
538 char *nla_strdup(const struct nlattr *nla, gfp_t flags);
539 int nla_memcpy(void *dest, const struct nlattr *src, int count);
540 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
541 int nla_strcmp(const struct nlattr *nla, const char *str);
542 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
543 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
544 int attrlen, int padattr);
545 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
546 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
547 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
548 int attrlen, int padattr);
549 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
550 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
551 const void *data);
552 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
553 const void *data, int padattr);
554 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
555 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
556 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
557 const void *data, int padattr);
558 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
559 int nla_append(struct sk_buff *skb, int attrlen, const void *data);
560
561 /**************************************************************************
562 * Netlink Messages
563 **************************************************************************/
564
565 /**
566 * nlmsg_msg_size - length of netlink message not including padding
567 * @payload: length of message payload
568 */
569 static inline int nlmsg_msg_size(int payload)
570 {
571 return NLMSG_HDRLEN + payload;
572 }
573
574 /**
575 * nlmsg_total_size - length of netlink message including padding
576 * @payload: length of message payload
577 */
578 static inline int nlmsg_total_size(int payload)
579 {
580 return NLMSG_ALIGN(nlmsg_msg_size(payload));
581 }
582
583 /**
584 * nlmsg_padlen - length of padding at the message's tail
585 * @payload: length of message payload
586 */
587 static inline int nlmsg_padlen(int payload)
588 {
589 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
590 }
591
592 /**
593 * nlmsg_data - head of message payload
594 * @nlh: netlink message header
595 */
596 static inline void *nlmsg_data(const struct nlmsghdr *nlh)
597 {
598 return (unsigned char *) nlh + NLMSG_HDRLEN;
599 }
600
601 /**
602 * nlmsg_len - length of message payload
603 * @nlh: netlink message header
604 */
605 static inline int nlmsg_len(const struct nlmsghdr *nlh)
606 {
607 return nlh->nlmsg_len - NLMSG_HDRLEN;
608 }
609
610 /**
611 * nlmsg_attrdata - head of attributes data
612 * @nlh: netlink message header
613 * @hdrlen: length of family specific header
614 */
615 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
616 int hdrlen)
617 {
618 unsigned char *data = nlmsg_data(nlh);
619 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
620 }
621
622 /**
623 * nlmsg_attrlen - length of attributes data
624 * @nlh: netlink message header
625 * @hdrlen: length of family specific header
626 */
627 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
628 {
629 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
630 }
631
632 /**
633 * nlmsg_ok - check if the netlink message fits into the remaining bytes
634 * @nlh: netlink message header
635 * @remaining: number of bytes remaining in message stream
636 */
637 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
638 {
639 return (remaining >= (int) sizeof(struct nlmsghdr) &&
640 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
641 nlh->nlmsg_len <= remaining);
642 }
643
644 /**
645 * nlmsg_next - next netlink message in message stream
646 * @nlh: netlink message header
647 * @remaining: number of bytes remaining in message stream
648 *
649 * Returns the next netlink message in the message stream and
650 * decrements remaining by the size of the current message.
651 */
652 static inline struct nlmsghdr *
653 nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
654 {
655 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
656
657 *remaining -= totlen;
658
659 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
660 }
661
662 /**
663 * nla_parse - Parse a stream of attributes into a tb buffer
664 * @tb: destination array with maxtype+1 elements
665 * @maxtype: maximum attribute type to be expected
666 * @head: head of attribute stream
667 * @len: length of attribute stream
668 * @policy: validation policy
669 * @extack: extended ACK pointer
670 *
671 * Parses a stream of attributes and stores a pointer to each attribute in
672 * the tb array accessible via the attribute type. Attributes with a type
673 * exceeding maxtype will be rejected, policy must be specified, attributes
674 * will be validated in the strictest way possible.
675 *
676 * Returns 0 on success or a negative error code.
677 */
678 static inline int nla_parse(struct nlattr **tb, int maxtype,
679 const struct nlattr *head, int len,
680 const struct nla_policy *policy,
681 struct netlink_ext_ack *extack)
682 {
683 return __nla_parse(tb, maxtype, head, len, policy,
684 NL_VALIDATE_STRICT, extack);
685 }
686
687 /**
688 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
689 * @tb: destination array with maxtype+1 elements
690 * @maxtype: maximum attribute type to be expected
691 * @head: head of attribute stream
692 * @len: length of attribute stream
693 * @policy: validation policy
694 * @extack: extended ACK pointer
695 *
696 * Parses a stream of attributes and stores a pointer to each attribute in
697 * the tb array accessible via the attribute type. Attributes with a type
698 * exceeding maxtype will be ignored and attributes from the policy are not
699 * always strictly validated (only for new attributes).
700 *
701 * Returns 0 on success or a negative error code.
702 */
703 static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
704 const struct nlattr *head, int len,
705 const struct nla_policy *policy,
706 struct netlink_ext_ack *extack)
707 {
708 return __nla_parse(tb, maxtype, head, len, policy,
709 NL_VALIDATE_LIBERAL, extack);
710 }
711
712 /**
713 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
714 * @tb: destination array with maxtype+1 elements
715 * @maxtype: maximum attribute type to be expected
716 * @head: head of attribute stream
717 * @len: length of attribute stream
718 * @policy: validation policy
719 * @extack: extended ACK pointer
720 *
721 * Parses a stream of attributes and stores a pointer to each attribute in
722 * the tb array accessible via the attribute type. Attributes with a type
723 * exceeding maxtype will be rejected as well as trailing data, but the
724 * policy is not completely strictly validated (only for new attributes).
725 *
726 * Returns 0 on success or a negative error code.
727 */
728 static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
729 const struct nlattr *head,
730 int len,
731 const struct nla_policy *policy,
732 struct netlink_ext_ack *extack)
733 {
734 return __nla_parse(tb, maxtype, head, len, policy,
735 NL_VALIDATE_DEPRECATED_STRICT, extack);
736 }
737
738 /**
739 * __nlmsg_parse - parse attributes of a netlink message
740 * @nlh: netlink message header
741 * @hdrlen: length of family specific header
742 * @tb: destination array with maxtype+1 elements
743 * @maxtype: maximum attribute type to be expected
744 * @policy: validation policy
745 * @validate: validation strictness
746 * @extack: extended ACK report struct
747 *
748 * See nla_parse()
749 */
750 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
751 struct nlattr *tb[], int maxtype,
752 const struct nla_policy *policy,
753 unsigned int validate,
754 struct netlink_ext_ack *extack)
755 {
756 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
757 NL_SET_ERR_MSG(extack, "Invalid header length");
758 return -EINVAL;
759 }
760
761 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
762 nlmsg_attrlen(nlh, hdrlen), policy, validate,
763 extack);
764 }
765
766 /**
767 * nlmsg_parse - parse attributes of a netlink message
768 * @nlh: netlink message header
769 * @hdrlen: length of family specific header
770 * @tb: destination array with maxtype+1 elements
771 * @maxtype: maximum attribute type to be expected
772 * @policy: validation policy
773 * @extack: extended ACK report struct
774 *
775 * See nla_parse()
776 */
777 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
778 struct nlattr *tb[], int maxtype,
779 const struct nla_policy *policy,
780 struct netlink_ext_ack *extack)
781 {
782 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
783 NL_VALIDATE_STRICT, extack);
784 }
785
786 /**
787 * nlmsg_parse_deprecated - parse attributes of a netlink message
788 * @nlh: netlink message header
789 * @hdrlen: length of family specific header
790 * @tb: destination array with maxtype+1 elements
791 * @maxtype: maximum attribute type to be expected
792 * @policy: validation policy
793 * @extack: extended ACK report struct
794 *
795 * See nla_parse_deprecated()
796 */
797 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
798 struct nlattr *tb[], int maxtype,
799 const struct nla_policy *policy,
800 struct netlink_ext_ack *extack)
801 {
802 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
803 NL_VALIDATE_LIBERAL, extack);
804 }
805
806 /**
807 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
808 * @nlh: netlink message header
809 * @hdrlen: length of family specific header
810 * @tb: destination array with maxtype+1 elements
811 * @maxtype: maximum attribute type to be expected
812 * @policy: validation policy
813 * @extack: extended ACK report struct
814 *
815 * See nla_parse_deprecated_strict()
816 */
817 static inline int
818 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
819 struct nlattr *tb[], int maxtype,
820 const struct nla_policy *policy,
821 struct netlink_ext_ack *extack)
822 {
823 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
824 NL_VALIDATE_DEPRECATED_STRICT, extack);
825 }
826
827 /**
828 * nlmsg_find_attr - find a specific attribute in a netlink message
829 * @nlh: netlink message header
830 * @hdrlen: length of familiy specific header
831 * @attrtype: type of attribute to look for
832 *
833 * Returns the first attribute which matches the specified type.
834 */
835 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
836 int hdrlen, int attrtype)
837 {
838 return nla_find(nlmsg_attrdata(nlh, hdrlen),
839 nlmsg_attrlen(nlh, hdrlen), attrtype);
840 }
841
842 /**
843 * nla_validate_deprecated - Validate a stream of attributes
844 * @head: head of attribute stream
845 * @len: length of attribute stream
846 * @maxtype: maximum attribute type to be expected
847 * @policy: validation policy
848 * @extack: extended ACK report struct
849 *
850 * Validates all attributes in the specified attribute stream against the
851 * specified policy. Validation is done in liberal mode.
852 * See documenation of struct nla_policy for more details.
853 *
854 * Returns 0 on success or a negative error code.
855 */
856 static inline int nla_validate_deprecated(const struct nlattr *head, int len,
857 int maxtype,
858 const struct nla_policy *policy,
859 struct netlink_ext_ack *extack)
860 {
861 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
862 extack);
863 }
864
865 /**
866 * nla_validate - Validate a stream of attributes
867 * @head: head of attribute stream
868 * @len: length of attribute stream
869 * @maxtype: maximum attribute type to be expected
870 * @policy: validation policy
871 * @extack: extended ACK report struct
872 *
873 * Validates all attributes in the specified attribute stream against the
874 * specified policy. Validation is done in strict mode.
875 * See documenation of struct nla_policy for more details.
876 *
877 * Returns 0 on success or a negative error code.
878 */
879 static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
880 const struct nla_policy *policy,
881 struct netlink_ext_ack *extack)
882 {
883 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
884 extack);
885 }
886
887 /**
888 * nlmsg_validate_deprecated - validate a netlink message including attributes
889 * @nlh: netlinket message header
890 * @hdrlen: length of familiy specific header
891 * @maxtype: maximum attribute type to be expected
892 * @policy: validation policy
893 * @extack: extended ACK report struct
894 */
895 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
896 int hdrlen, int maxtype,
897 const struct nla_policy *policy,
898 struct netlink_ext_ack *extack)
899 {
900 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
901 return -EINVAL;
902
903 return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
904 nlmsg_attrlen(nlh, hdrlen), maxtype,
905 policy, NL_VALIDATE_LIBERAL, extack);
906 }
907
908
909
910 /**
911 * nlmsg_report - need to report back to application?
912 * @nlh: netlink message header
913 *
914 * Returns 1 if a report back to the application is requested.
915 */
916 static inline int nlmsg_report(const struct nlmsghdr *nlh)
917 {
918 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
919 }
920
921 /**
922 * nlmsg_seq - return the seq number of netlink message
923 * @nlh: netlink message header
924 *
925 * Returns 0 if netlink message is NULL
926 */
927 static inline u32 nlmsg_seq(const struct nlmsghdr *nlh)
928 {
929 return nlh ? nlh->nlmsg_seq : 0;
930 }
931
932 /**
933 * nlmsg_for_each_attr - iterate over a stream of attributes
934 * @pos: loop counter, set to current attribute
935 * @nlh: netlink message header
936 * @hdrlen: length of familiy specific header
937 * @rem: initialized to len, holds bytes currently remaining in stream
938 */
939 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
940 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
941 nlmsg_attrlen(nlh, hdrlen), rem)
942
943 /**
944 * nlmsg_put - Add a new netlink message to an skb
945 * @skb: socket buffer to store message in
946 * @portid: netlink PORTID of requesting application
947 * @seq: sequence number of message
948 * @type: message type
949 * @payload: length of message payload
950 * @flags: message flags
951 *
952 * Returns NULL if the tailroom of the skb is insufficient to store
953 * the message header and payload.
954 */
955 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
956 int type, int payload, int flags)
957 {
958 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
959 return NULL;
960
961 return __nlmsg_put(skb, portid, seq, type, payload, flags);
962 }
963
964 /**
965 * nlmsg_append - Add more data to a nlmsg in a skb
966 * @skb: socket buffer to store message in
967 * @size: length of message payload
968 *
969 * Append data to an existing nlmsg, used when constructing a message
970 * with multiple fixed-format headers (which is rare).
971 * Returns NULL if the tailroom of the skb is insufficient to store
972 * the extra payload.
973 */
974 static inline void *nlmsg_append(struct sk_buff *skb, u32 size)
975 {
976 if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size)))
977 return NULL;
978
979 if (NLMSG_ALIGN(size) - size)
980 memset(skb_tail_pointer(skb) + size, 0,
981 NLMSG_ALIGN(size) - size);
982 return __skb_put(skb, NLMSG_ALIGN(size));
983 }
984
985 /**
986 * nlmsg_put_answer - Add a new callback based netlink message to an skb
987 * @skb: socket buffer to store message in
988 * @cb: netlink callback
989 * @type: message type
990 * @payload: length of message payload
991 * @flags: message flags
992 *
993 * Returns NULL if the tailroom of the skb is insufficient to store
994 * the message header and payload.
995 */
996 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
997 struct netlink_callback *cb,
998 int type, int payload,
999 int flags)
1000 {
1001 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1002 type, payload, flags);
1003 }
1004
1005 /**
1006 * nlmsg_new - Allocate a new netlink message
1007 * @payload: size of the message payload
1008 * @flags: the type of memory to allocate.
1009 *
1010 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
1011 * and a good default is needed.
1012 */
1013 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
1014 {
1015 return alloc_skb(nlmsg_total_size(payload), flags);
1016 }
1017
1018 /**
1019 * nlmsg_new_large - Allocate a new netlink message with non-contiguous
1020 * physical memory
1021 * @payload: size of the message payload
1022 *
1023 * The allocated skb is unable to have frag page for shinfo->frags*,
1024 * as the NULL setting for skb->head in netlink_skb_destructor() will
1025 * bypass most of the handling in skb_release_data()
1026 */
1027 static inline struct sk_buff *nlmsg_new_large(size_t payload)
1028 {
1029 return netlink_alloc_large_skb(nlmsg_total_size(payload), 0);
1030 }
1031
1032 /**
1033 * nlmsg_end - Finalize a netlink message
1034 * @skb: socket buffer the message is stored in
1035 * @nlh: netlink message header
1036 *
1037 * Corrects the netlink message header to include the appeneded
1038 * attributes. Only necessary if attributes have been added to
1039 * the message.
1040 */
1041 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
1042 {
1043 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
1044 }
1045
1046 /**
1047 * nlmsg_get_pos - return current position in netlink message
1048 * @skb: socket buffer the message is stored in
1049 *
1050 * Returns a pointer to the current tail of the message.
1051 */
1052 static inline void *nlmsg_get_pos(struct sk_buff *skb)
1053 {
1054 return skb_tail_pointer(skb);
1055 }
1056
1057 /**
1058 * nlmsg_trim - Trim message to a mark
1059 * @skb: socket buffer the message is stored in
1060 * @mark: mark to trim to
1061 *
1062 * Trims the message to the provided mark.
1063 */
1064 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1065 {
1066 if (mark) {
1067 WARN_ON((unsigned char *) mark < skb->data);
1068 skb_trim(skb, (unsigned char *) mark - skb->data);
1069 }
1070 }
1071
1072 /**
1073 * nlmsg_cancel - Cancel construction of a netlink message
1074 * @skb: socket buffer the message is stored in
1075 * @nlh: netlink message header
1076 *
1077 * Removes the complete netlink message including all
1078 * attributes from the socket buffer again.
1079 */
1080 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1081 {
1082 nlmsg_trim(skb, nlh);
1083 }
1084
1085 /**
1086 * nlmsg_free - drop a netlink message
1087 * @skb: socket buffer of netlink message
1088 */
1089 static inline void nlmsg_free(struct sk_buff *skb)
1090 {
1091 kfree_skb(skb);
1092 }
1093
1094 /**
1095 * nlmsg_consume - free a netlink message
1096 * @skb: socket buffer of netlink message
1097 */
1098 static inline void nlmsg_consume(struct sk_buff *skb)
1099 {
1100 consume_skb(skb);
1101 }
1102
1103 /**
1104 * nlmsg_multicast_filtered - multicast a netlink message with filter function
1105 * @sk: netlink socket to spread messages to
1106 * @skb: netlink message as socket buffer
1107 * @portid: own netlink portid to avoid sending to yourself
1108 * @group: multicast group id
1109 * @flags: allocation flags
1110 * @filter: filter function
1111 * @filter_data: filter function private data
1112 *
1113 * Return: 0 on success, negative error code for failure.
1114 */
1115 static inline int nlmsg_multicast_filtered(struct sock *sk, struct sk_buff *skb,
1116 u32 portid, unsigned int group,
1117 gfp_t flags,
1118 netlink_filter_fn filter,
1119 void *filter_data)
1120 {
1121 int err;
1122
1123 NETLINK_CB(skb).dst_group = group;
1124
1125 err = netlink_broadcast_filtered(sk, skb, portid, group, flags,
1126 filter, filter_data);
1127 if (err > 0)
1128 err = 0;
1129
1130 return err;
1131 }
1132
1133 /**
1134 * nlmsg_multicast - multicast a netlink message
1135 * @sk: netlink socket to spread messages to
1136 * @skb: netlink message as socket buffer
1137 * @portid: own netlink portid to avoid sending to yourself
1138 * @group: multicast group id
1139 * @flags: allocation flags
1140 */
1141 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1142 u32 portid, unsigned int group, gfp_t flags)
1143 {
1144 return nlmsg_multicast_filtered(sk, skb, portid, group, flags,
1145 NULL, NULL);
1146 }
1147
1148 /**
1149 * nlmsg_unicast - unicast a netlink message
1150 * @sk: netlink socket to spread message to
1151 * @skb: netlink message as socket buffer
1152 * @portid: netlink portid of the destination socket
1153 */
1154 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1155 {
1156 int err;
1157
1158 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1159 if (err > 0)
1160 err = 0;
1161
1162 return err;
1163 }
1164
1165 /**
1166 * nlmsg_for_each_msg - iterate over a stream of messages
1167 * @pos: loop counter, set to current message
1168 * @head: head of message stream
1169 * @len: length of message stream
1170 * @rem: initialized to len, holds bytes currently remaining in stream
1171 */
1172 #define nlmsg_for_each_msg(pos, head, len, rem) \
1173 for (pos = head, rem = len; \
1174 nlmsg_ok(pos, rem); \
1175 pos = nlmsg_next(pos, &(rem)))
1176
1177 /**
1178 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1179 * @cb: netlink callback structure that stores the sequence number
1180 * @nlh: netlink message header to write the flag to
1181 *
1182 * This function checks if the sequence (generation) number changed during dump
1183 * and if it did, advertises it in the netlink message header.
1184 *
1185 * The correct way to use it is to set cb->seq to the generation counter when
1186 * all locks for dumping have been acquired, and then call this function for
1187 * each message that is generated.
1188 *
1189 * Note that due to initialisation concerns, 0 is an invalid sequence number
1190 * and must not be used by code that uses this functionality.
1191 */
1192 static inline void
1193 nl_dump_check_consistent(struct netlink_callback *cb,
1194 struct nlmsghdr *nlh)
1195 {
1196 if (cb->prev_seq && cb->seq != cb->prev_seq)
1197 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1198 cb->prev_seq = cb->seq;
1199 }
1200
1201 /**************************************************************************
1202 * Netlink Attributes
1203 **************************************************************************/
1204
1205 /**
1206 * nla_attr_size - length of attribute not including padding
1207 * @payload: length of payload
1208 */
1209 static inline int nla_attr_size(int payload)
1210 {
1211 return NLA_HDRLEN + payload;
1212 }
1213
1214 /**
1215 * nla_total_size - total length of attribute including padding
1216 * @payload: length of payload
1217 */
1218 static inline int nla_total_size(int payload)
1219 {
1220 return NLA_ALIGN(nla_attr_size(payload));
1221 }
1222
1223 /**
1224 * nla_padlen - length of padding at the tail of attribute
1225 * @payload: length of payload
1226 */
1227 static inline int nla_padlen(int payload)
1228 {
1229 return nla_total_size(payload) - nla_attr_size(payload);
1230 }
1231
1232 /**
1233 * nla_type - attribute type
1234 * @nla: netlink attribute
1235 */
1236 static inline int nla_type(const struct nlattr *nla)
1237 {
1238 return nla->nla_type & NLA_TYPE_MASK;
1239 }
1240
1241 /**
1242 * nla_data - head of payload
1243 * @nla: netlink attribute
1244 */
1245 static inline void *nla_data(const struct nlattr *nla)
1246 {
1247 return (char *) nla + NLA_HDRLEN;
1248 }
1249
1250 /**
1251 * nla_len - length of payload
1252 * @nla: netlink attribute
1253 */
1254 static inline u16 nla_len(const struct nlattr *nla)
1255 {
1256 return nla->nla_len - NLA_HDRLEN;
1257 }
1258
1259 /**
1260 * nla_ok - check if the netlink attribute fits into the remaining bytes
1261 * @nla: netlink attribute
1262 * @remaining: number of bytes remaining in attribute stream
1263 */
1264 static inline int nla_ok(const struct nlattr *nla, int remaining)
1265 {
1266 return remaining >= (int) sizeof(*nla) &&
1267 nla->nla_len >= sizeof(*nla) &&
1268 nla->nla_len <= remaining;
1269 }
1270
1271 /**
1272 * nla_next - next netlink attribute in attribute stream
1273 * @nla: netlink attribute
1274 * @remaining: number of bytes remaining in attribute stream
1275 *
1276 * Returns the next netlink attribute in the attribute stream and
1277 * decrements remaining by the size of the current attribute.
1278 */
1279 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1280 {
1281 unsigned int totlen = NLA_ALIGN(nla->nla_len);
1282
1283 *remaining -= totlen;
1284 return (struct nlattr *) ((char *) nla + totlen);
1285 }
1286
1287 /**
1288 * nla_find_nested - find attribute in a set of nested attributes
1289 * @nla: attribute containing the nested attributes
1290 * @attrtype: type of attribute to look for
1291 *
1292 * Returns the first attribute which matches the specified type.
1293 */
1294 static inline struct nlattr *
1295 nla_find_nested(const struct nlattr *nla, int attrtype)
1296 {
1297 return nla_find(nla_data(nla), nla_len(nla), attrtype);
1298 }
1299
1300 /**
1301 * nla_parse_nested - parse nested attributes
1302 * @tb: destination array with maxtype+1 elements
1303 * @maxtype: maximum attribute type to be expected
1304 * @nla: attribute containing the nested attributes
1305 * @policy: validation policy
1306 * @extack: extended ACK report struct
1307 *
1308 * See nla_parse()
1309 */
1310 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1311 const struct nlattr *nla,
1312 const struct nla_policy *policy,
1313 struct netlink_ext_ack *extack)
1314 {
1315 if (!(nla->nla_type & NLA_F_NESTED)) {
1316 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1317 return -EINVAL;
1318 }
1319
1320 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1321 NL_VALIDATE_STRICT, extack);
1322 }
1323
1324 /**
1325 * nla_parse_nested_deprecated - parse nested attributes
1326 * @tb: destination array with maxtype+1 elements
1327 * @maxtype: maximum attribute type to be expected
1328 * @nla: attribute containing the nested attributes
1329 * @policy: validation policy
1330 * @extack: extended ACK report struct
1331 *
1332 * See nla_parse_deprecated()
1333 */
1334 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1335 const struct nlattr *nla,
1336 const struct nla_policy *policy,
1337 struct netlink_ext_ack *extack)
1338 {
1339 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1340 NL_VALIDATE_LIBERAL, extack);
1341 }
1342
1343 /**
1344 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1345 * @skb: socket buffer to add attribute to
1346 * @attrtype: attribute type
1347 * @value: numeric value
1348 */
1349 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1350 {
1351 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
1352 u8 tmp = value;
1353
1354 return nla_put(skb, attrtype, sizeof(u8), &tmp);
1355 }
1356
1357 /**
1358 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1359 * @skb: socket buffer to add attribute to
1360 * @attrtype: attribute type
1361 * @value: numeric value
1362 */
1363 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1364 {
1365 u16 tmp = value;
1366
1367 return nla_put(skb, attrtype, sizeof(u16), &tmp);
1368 }
1369
1370 /**
1371 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1372 * @skb: socket buffer to add attribute to
1373 * @attrtype: attribute type
1374 * @value: numeric value
1375 */
1376 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1377 {
1378 __be16 tmp = value;
1379
1380 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1381 }
1382
1383 /**
1384 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1385 * @skb: socket buffer to add attribute to
1386 * @attrtype: attribute type
1387 * @value: numeric value
1388 */
1389 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1390 {
1391 __be16 tmp = value;
1392
1393 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1394 }
1395
1396 /**
1397 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1398 * @skb: socket buffer to add attribute to
1399 * @attrtype: attribute type
1400 * @value: numeric value
1401 */
1402 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1403 {
1404 __le16 tmp = value;
1405
1406 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1407 }
1408
1409 /**
1410 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1411 * @skb: socket buffer to add attribute to
1412 * @attrtype: attribute type
1413 * @value: numeric value
1414 */
1415 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1416 {
1417 u32 tmp = value;
1418
1419 return nla_put(skb, attrtype, sizeof(u32), &tmp);
1420 }
1421
1422 /**
1423 * nla_put_uint - Add a variable-size unsigned int to a socket buffer
1424 * @skb: socket buffer to add attribute to
1425 * @attrtype: attribute type
1426 * @value: numeric value
1427 */
1428 static inline int nla_put_uint(struct sk_buff *skb, int attrtype, u64 value)
1429 {
1430 u64 tmp64 = value;
1431 u32 tmp32 = value;
1432
1433 if (tmp64 == tmp32)
1434 return nla_put_u32(skb, attrtype, tmp32);
1435 return nla_put(skb, attrtype, sizeof(u64), &tmp64);
1436 }
1437
1438 /**
1439 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1440 * @skb: socket buffer to add attribute to
1441 * @attrtype: attribute type
1442 * @value: numeric value
1443 */
1444 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1445 {
1446 __be32 tmp = value;
1447
1448 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1449 }
1450
1451 /**
1452 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1453 * @skb: socket buffer to add attribute to
1454 * @attrtype: attribute type
1455 * @value: numeric value
1456 */
1457 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1458 {
1459 __be32 tmp = value;
1460
1461 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1462 }
1463
1464 /**
1465 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1466 * @skb: socket buffer to add attribute to
1467 * @attrtype: attribute type
1468 * @value: numeric value
1469 */
1470 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1471 {
1472 __le32 tmp = value;
1473
1474 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1475 }
1476
1477 /**
1478 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1479 * @skb: socket buffer to add attribute to
1480 * @attrtype: attribute type
1481 * @value: numeric value
1482 * @padattr: attribute type for the padding
1483 */
1484 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1485 u64 value, int padattr)
1486 {
1487 u64 tmp = value;
1488
1489 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1490 }
1491
1492 /**
1493 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1494 * @skb: socket buffer to add attribute to
1495 * @attrtype: attribute type
1496 * @value: numeric value
1497 * @padattr: attribute type for the padding
1498 */
1499 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1500 int padattr)
1501 {
1502 __be64 tmp = value;
1503
1504 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1505 }
1506
1507 /**
1508 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1509 * @skb: socket buffer to add attribute to
1510 * @attrtype: attribute type
1511 * @value: numeric value
1512 * @padattr: attribute type for the padding
1513 */
1514 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1515 int padattr)
1516 {
1517 __be64 tmp = value;
1518
1519 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1520 padattr);
1521 }
1522
1523 /**
1524 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1525 * @skb: socket buffer to add attribute to
1526 * @attrtype: attribute type
1527 * @value: numeric value
1528 * @padattr: attribute type for the padding
1529 */
1530 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1531 int padattr)
1532 {
1533 __le64 tmp = value;
1534
1535 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1536 }
1537
1538 /**
1539 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1540 * @skb: socket buffer to add attribute to
1541 * @attrtype: attribute type
1542 * @value: numeric value
1543 */
1544 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1545 {
1546 s8 tmp = value;
1547
1548 return nla_put(skb, attrtype, sizeof(s8), &tmp);
1549 }
1550
1551 /**
1552 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1553 * @skb: socket buffer to add attribute to
1554 * @attrtype: attribute type
1555 * @value: numeric value
1556 */
1557 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1558 {
1559 s16 tmp = value;
1560
1561 return nla_put(skb, attrtype, sizeof(s16), &tmp);
1562 }
1563
1564 /**
1565 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1566 * @skb: socket buffer to add attribute to
1567 * @attrtype: attribute type
1568 * @value: numeric value
1569 */
1570 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1571 {
1572 s32 tmp = value;
1573
1574 return nla_put(skb, attrtype, sizeof(s32), &tmp);
1575 }
1576
1577 /**
1578 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1579 * @skb: socket buffer to add attribute to
1580 * @attrtype: attribute type
1581 * @value: numeric value
1582 * @padattr: attribute type for the padding
1583 */
1584 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1585 int padattr)
1586 {
1587 s64 tmp = value;
1588
1589 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1590 }
1591
1592 /**
1593 * nla_put_sint - Add a variable-size signed int to a socket buffer
1594 * @skb: socket buffer to add attribute to
1595 * @attrtype: attribute type
1596 * @value: numeric value
1597 */
1598 static inline int nla_put_sint(struct sk_buff *skb, int attrtype, s64 value)
1599 {
1600 s64 tmp64 = value;
1601 s32 tmp32 = value;
1602
1603 if (tmp64 == tmp32)
1604 return nla_put_s32(skb, attrtype, tmp32);
1605 return nla_put(skb, attrtype, sizeof(s64), &tmp64);
1606 }
1607
1608 /**
1609 * nla_put_string - Add a string netlink attribute to a socket buffer
1610 * @skb: socket buffer to add attribute to
1611 * @attrtype: attribute type
1612 * @str: NUL terminated string
1613 */
1614 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1615 const char *str)
1616 {
1617 return nla_put(skb, attrtype, strlen(str) + 1, str);
1618 }
1619
1620 /**
1621 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1622 * @skb: socket buffer to add attribute to
1623 * @attrtype: attribute type
1624 */
1625 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1626 {
1627 return nla_put(skb, attrtype, 0, NULL);
1628 }
1629
1630 /**
1631 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1632 * @skb: socket buffer to add attribute to
1633 * @attrtype: attribute type
1634 * @njiffies: number of jiffies to convert to msecs
1635 * @padattr: attribute type for the padding
1636 */
1637 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1638 unsigned long njiffies, int padattr)
1639 {
1640 u64 tmp = jiffies_to_msecs(njiffies);
1641
1642 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1643 }
1644
1645 /**
1646 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1647 * buffer
1648 * @skb: socket buffer to add attribute to
1649 * @attrtype: attribute type
1650 * @addr: IPv4 address
1651 */
1652 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1653 __be32 addr)
1654 {
1655 __be32 tmp = addr;
1656
1657 return nla_put_be32(skb, attrtype, tmp);
1658 }
1659
1660 /**
1661 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1662 * buffer
1663 * @skb: socket buffer to add attribute to
1664 * @attrtype: attribute type
1665 * @addr: IPv6 address
1666 */
1667 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1668 const struct in6_addr *addr)
1669 {
1670 return nla_put(skb, attrtype, sizeof(*addr), addr);
1671 }
1672
1673 /**
1674 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1675 * @skb: socket buffer to add attribute to
1676 * @attrtype: attribute type
1677 * @value: value carrying bits
1678 * @selector: selector of valid bits
1679 */
1680 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1681 __u32 value, __u32 selector)
1682 {
1683 struct nla_bitfield32 tmp = { value, selector, };
1684
1685 return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1686 }
1687
1688 /**
1689 * nla_get_u32 - return payload of u32 attribute
1690 * @nla: u32 netlink attribute
1691 */
1692 static inline u32 nla_get_u32(const struct nlattr *nla)
1693 {
1694 return *(u32 *) nla_data(nla);
1695 }
1696
1697 /**
1698 * nla_get_be32 - return payload of __be32 attribute
1699 * @nla: __be32 netlink attribute
1700 */
1701 static inline __be32 nla_get_be32(const struct nlattr *nla)
1702 {
1703 return *(__be32 *) nla_data(nla);
1704 }
1705
1706 /**
1707 * nla_get_le32 - return payload of __le32 attribute
1708 * @nla: __le32 netlink attribute
1709 */
1710 static inline __le32 nla_get_le32(const struct nlattr *nla)
1711 {
1712 return *(__le32 *) nla_data(nla);
1713 }
1714
1715 /**
1716 * nla_get_u16 - return payload of u16 attribute
1717 * @nla: u16 netlink attribute
1718 */
1719 static inline u16 nla_get_u16(const struct nlattr *nla)
1720 {
1721 return *(u16 *) nla_data(nla);
1722 }
1723
1724 /**
1725 * nla_get_be16 - return payload of __be16 attribute
1726 * @nla: __be16 netlink attribute
1727 */
1728 static inline __be16 nla_get_be16(const struct nlattr *nla)
1729 {
1730 return *(__be16 *) nla_data(nla);
1731 }
1732
1733 /**
1734 * nla_get_le16 - return payload of __le16 attribute
1735 * @nla: __le16 netlink attribute
1736 */
1737 static inline __le16 nla_get_le16(const struct nlattr *nla)
1738 {
1739 return *(__le16 *) nla_data(nla);
1740 }
1741
1742 /**
1743 * nla_get_u8 - return payload of u8 attribute
1744 * @nla: u8 netlink attribute
1745 */
1746 static inline u8 nla_get_u8(const struct nlattr *nla)
1747 {
1748 return *(u8 *) nla_data(nla);
1749 }
1750
1751 /**
1752 * nla_get_u64 - return payload of u64 attribute
1753 * @nla: u64 netlink attribute
1754 */
1755 static inline u64 nla_get_u64(const struct nlattr *nla)
1756 {
1757 u64 tmp;
1758
1759 nla_memcpy(&tmp, nla, sizeof(tmp));
1760
1761 return tmp;
1762 }
1763
1764 /**
1765 * nla_get_uint - return payload of uint attribute
1766 * @nla: uint netlink attribute
1767 */
1768 static inline u64 nla_get_uint(const struct nlattr *nla)
1769 {
1770 if (nla_len(nla) == sizeof(u32))
1771 return nla_get_u32(nla);
1772 return nla_get_u64(nla);
1773 }
1774
1775 /**
1776 * nla_get_be64 - return payload of __be64 attribute
1777 * @nla: __be64 netlink attribute
1778 */
1779 static inline __be64 nla_get_be64(const struct nlattr *nla)
1780 {
1781 __be64 tmp;
1782
1783 nla_memcpy(&tmp, nla, sizeof(tmp));
1784
1785 return tmp;
1786 }
1787
1788 /**
1789 * nla_get_le64 - return payload of __le64 attribute
1790 * @nla: __le64 netlink attribute
1791 */
1792 static inline __le64 nla_get_le64(const struct nlattr *nla)
1793 {
1794 return *(__le64 *) nla_data(nla);
1795 }
1796
1797 /**
1798 * nla_get_s32 - return payload of s32 attribute
1799 * @nla: s32 netlink attribute
1800 */
1801 static inline s32 nla_get_s32(const struct nlattr *nla)
1802 {
1803 return *(s32 *) nla_data(nla);
1804 }
1805
1806 /**
1807 * nla_get_s16 - return payload of s16 attribute
1808 * @nla: s16 netlink attribute
1809 */
1810 static inline s16 nla_get_s16(const struct nlattr *nla)
1811 {
1812 return *(s16 *) nla_data(nla);
1813 }
1814
1815 /**
1816 * nla_get_s8 - return payload of s8 attribute
1817 * @nla: s8 netlink attribute
1818 */
1819 static inline s8 nla_get_s8(const struct nlattr *nla)
1820 {
1821 return *(s8 *) nla_data(nla);
1822 }
1823
1824 /**
1825 * nla_get_s64 - return payload of s64 attribute
1826 * @nla: s64 netlink attribute
1827 */
1828 static inline s64 nla_get_s64(const struct nlattr *nla)
1829 {
1830 s64 tmp;
1831
1832 nla_memcpy(&tmp, nla, sizeof(tmp));
1833
1834 return tmp;
1835 }
1836
1837 /**
1838 * nla_get_sint - return payload of uint attribute
1839 * @nla: uint netlink attribute
1840 */
1841 static inline s64 nla_get_sint(const struct nlattr *nla)
1842 {
1843 if (nla_len(nla) == sizeof(s32))
1844 return nla_get_s32(nla);
1845 return nla_get_s64(nla);
1846 }
1847
1848 /**
1849 * nla_get_flag - return payload of flag attribute
1850 * @nla: flag netlink attribute
1851 */
1852 static inline int nla_get_flag(const struct nlattr *nla)
1853 {
1854 return !!nla;
1855 }
1856
1857 /**
1858 * nla_get_msecs - return payload of msecs attribute
1859 * @nla: msecs netlink attribute
1860 *
1861 * Returns the number of milliseconds in jiffies.
1862 */
1863 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1864 {
1865 u64 msecs = nla_get_u64(nla);
1866
1867 return msecs_to_jiffies((unsigned long) msecs);
1868 }
1869
1870 /**
1871 * nla_get_in_addr - return payload of IPv4 address attribute
1872 * @nla: IPv4 address netlink attribute
1873 */
1874 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1875 {
1876 return *(__be32 *) nla_data(nla);
1877 }
1878
1879 /**
1880 * nla_get_in6_addr - return payload of IPv6 address attribute
1881 * @nla: IPv6 address netlink attribute
1882 */
1883 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1884 {
1885 struct in6_addr tmp;
1886
1887 nla_memcpy(&tmp, nla, sizeof(tmp));
1888 return tmp;
1889 }
1890
1891 /**
1892 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1893 * @nla: nla_bitfield32 attribute
1894 */
1895 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1896 {
1897 struct nla_bitfield32 tmp;
1898
1899 nla_memcpy(&tmp, nla, sizeof(tmp));
1900 return tmp;
1901 }
1902
1903 /**
1904 * nla_memdup - duplicate attribute memory (kmemdup)
1905 * @src: netlink attribute to duplicate from
1906 * @gfp: GFP mask
1907 */
1908 static inline void *nla_memdup_noprof(const struct nlattr *src, gfp_t gfp)
1909 {
1910 return kmemdup_noprof(nla_data(src), nla_len(src), gfp);
1911 }
1912 #define nla_memdup(...) alloc_hooks(nla_memdup_noprof(__VA_ARGS__))
1913
1914 /**
1915 * nla_nest_start_noflag - Start a new level of nested attributes
1916 * @skb: socket buffer to add attributes to
1917 * @attrtype: attribute type of container
1918 *
1919 * This function exists for backward compatibility to use in APIs which never
1920 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1921 * nla_nest_start() which sets the flag.
1922 *
1923 * Returns the container attribute or NULL on error
1924 */
1925 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1926 int attrtype)
1927 {
1928 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1929
1930 if (nla_put(skb, attrtype, 0, NULL) < 0)
1931 return NULL;
1932
1933 return start;
1934 }
1935
1936 /**
1937 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1938 * @skb: socket buffer to add attributes to
1939 * @attrtype: attribute type of container
1940 *
1941 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1942 * flag. This is the preferred function to use in new code.
1943 *
1944 * Returns the container attribute or NULL on error
1945 */
1946 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1947 {
1948 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1949 }
1950
1951 /**
1952 * nla_nest_end - Finalize nesting of attributes
1953 * @skb: socket buffer the attributes are stored in
1954 * @start: container attribute
1955 *
1956 * Corrects the container attribute header to include the all
1957 * appeneded attributes.
1958 *
1959 * Returns the total data length of the skb.
1960 */
1961 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1962 {
1963 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1964 return skb->len;
1965 }
1966
1967 /**
1968 * nla_nest_cancel - Cancel nesting of attributes
1969 * @skb: socket buffer the message is stored in
1970 * @start: container attribute
1971 *
1972 * Removes the container attribute and including all nested
1973 * attributes. Returns -EMSGSIZE
1974 */
1975 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1976 {
1977 nlmsg_trim(skb, start);
1978 }
1979
1980 /**
1981 * __nla_validate_nested - Validate a stream of nested attributes
1982 * @start: container attribute
1983 * @maxtype: maximum attribute type to be expected
1984 * @policy: validation policy
1985 * @validate: validation strictness
1986 * @extack: extended ACK report struct
1987 *
1988 * Validates all attributes in the nested attribute stream against the
1989 * specified policy. Attributes with a type exceeding maxtype will be
1990 * ignored. See documenation of struct nla_policy for more details.
1991 *
1992 * Returns 0 on success or a negative error code.
1993 */
1994 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1995 const struct nla_policy *policy,
1996 unsigned int validate,
1997 struct netlink_ext_ack *extack)
1998 {
1999 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
2000 validate, extack);
2001 }
2002
2003 static inline int
2004 nla_validate_nested(const struct nlattr *start, int maxtype,
2005 const struct nla_policy *policy,
2006 struct netlink_ext_ack *extack)
2007 {
2008 return __nla_validate_nested(start, maxtype, policy,
2009 NL_VALIDATE_STRICT, extack);
2010 }
2011
2012 static inline int
2013 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
2014 const struct nla_policy *policy,
2015 struct netlink_ext_ack *extack)
2016 {
2017 return __nla_validate_nested(start, maxtype, policy,
2018 NL_VALIDATE_LIBERAL, extack);
2019 }
2020
2021 /**
2022 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
2023 * @skb: socket buffer the message is stored in
2024 *
2025 * Return true if padding is needed to align the next attribute (nla_data()) to
2026 * a 64-bit aligned area.
2027 */
2028 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
2029 {
2030 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2031 /* The nlattr header is 4 bytes in size, that's why we test
2032 * if the skb->data _is_ aligned. A NOP attribute, plus
2033 * nlattr header for next attribute, will make nla_data()
2034 * 8-byte aligned.
2035 */
2036 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
2037 return true;
2038 #endif
2039 return false;
2040 }
2041
2042 /**
2043 * nla_align_64bit - 64-bit align the nla_data() of next attribute
2044 * @skb: socket buffer the message is stored in
2045 * @padattr: attribute type for the padding
2046 *
2047 * Conditionally emit a padding netlink attribute in order to make
2048 * the next attribute we emit have a 64-bit aligned nla_data() area.
2049 * This will only be done in architectures which do not have
2050 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
2051 *
2052 * Returns zero on success or a negative error code.
2053 */
2054 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
2055 {
2056 if (nla_need_padding_for_64bit(skb) &&
2057 !nla_reserve(skb, padattr, 0))
2058 return -EMSGSIZE;
2059
2060 return 0;
2061 }
2062
2063 /**
2064 * nla_total_size_64bit - total length of attribute including padding
2065 * @payload: length of payload
2066 */
2067 static inline int nla_total_size_64bit(int payload)
2068 {
2069 return NLA_ALIGN(nla_attr_size(payload))
2070 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2071 + NLA_ALIGN(nla_attr_size(0))
2072 #endif
2073 ;
2074 }
2075
2076 /**
2077 * nla_for_each_attr - iterate over a stream of attributes
2078 * @pos: loop counter, set to current attribute
2079 * @head: head of attribute stream
2080 * @len: length of attribute stream
2081 * @rem: initialized to len, holds bytes currently remaining in stream
2082 */
2083 #define nla_for_each_attr(pos, head, len, rem) \
2084 for (pos = head, rem = len; \
2085 nla_ok(pos, rem); \
2086 pos = nla_next(pos, &(rem)))
2087
2088 /**
2089 * nla_for_each_attr_type - iterate over a stream of attributes
2090 * @pos: loop counter, set to current attribute
2091 * @type: required attribute type for @pos
2092 * @head: head of attribute stream
2093 * @len: length of attribute stream
2094 * @rem: initialized to len, holds bytes currently remaining in stream
2095 */
2096 #define nla_for_each_attr_type(pos, type, head, len, rem) \
2097 nla_for_each_attr(pos, head, len, rem) \
2098 if (nla_type(pos) == type)
2099
2100 /**
2101 * nla_for_each_nested - iterate over nested attributes
2102 * @pos: loop counter, set to current attribute
2103 * @nla: attribute containing the nested attributes
2104 * @rem: initialized to len, holds bytes currently remaining in stream
2105 */
2106 #define nla_for_each_nested(pos, nla, rem) \
2107 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
2108
2109 /**
2110 * nla_for_each_nested_type - iterate over nested attributes
2111 * @pos: loop counter, set to current attribute
2112 * @type: required attribute type for @pos
2113 * @nla: attribute containing the nested attributes
2114 * @rem: initialized to len, holds bytes currently remaining in stream
2115 */
2116 #define nla_for_each_nested_type(pos, type, nla, rem) \
2117 nla_for_each_nested(pos, nla, rem) \
2118 if (nla_type(pos) == type)
2119
2120 /**
2121 * nla_is_last - Test if attribute is last in stream
2122 * @nla: attribute to test
2123 * @rem: bytes remaining in stream
2124 */
2125 static inline bool nla_is_last(const struct nlattr *nla, int rem)
2126 {
2127 return nla->nla_len == rem;
2128 }
2129
2130 void nla_get_range_unsigned(const struct nla_policy *pt,
2131 struct netlink_range_validation *range);
2132 void nla_get_range_signed(const struct nla_policy *pt,
2133 struct netlink_range_validation_signed *range);
2134
2135 struct netlink_policy_dump_state;
2136
2137 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
2138 const struct nla_policy *policy,
2139 unsigned int maxtype);
2140 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
2141 const struct nla_policy *policy,
2142 unsigned int maxtype);
2143 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
2144 int netlink_policy_dump_write(struct sk_buff *skb,
2145 struct netlink_policy_dump_state *state);
2146 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
2147 int netlink_policy_dump_write_attr(struct sk_buff *skb,
2148 const struct nla_policy *pt,
2149 int nestattr);
2150 void netlink_policy_dump_free(struct netlink_policy_dump_state *state);
2151
2152 #endif
2153
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