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