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_strlcpy(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_EXACT_LEN,
185 NLA_EXACT_LEN_WARN,
186 NLA_MIN_LEN,
187 __NLA_TYPE_MAX,
188 };
189
190 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
191
192 enum nla_policy_validation {
193 NLA_VALIDATE_NONE,
194 NLA_VALIDATE_RANGE,
195 NLA_VALIDATE_MIN,
196 NLA_VALIDATE_MAX,
197 NLA_VALIDATE_FUNCTION,
198 };
199
200 /**
201 * struct nla_policy - attribute validation policy
202 * @type: Type of attribute or NLA_UNSPEC
203 * @validation_type: type of attribute validation done in addition to
204 * type-specific validation (e.g. range, function call), see
205 * &enum nla_policy_validation
206 * @len: Type specific length of payload
207 *
208 * Policies are defined as arrays of this struct, the array must be
209 * accessible by attribute type up to the highest identifier to be expected.
210 *
211 * Meaning of `len' field:
212 * NLA_STRING Maximum length of string
213 * NLA_NUL_STRING Maximum length of string (excluding NUL)
214 * NLA_FLAG Unused
215 * NLA_BINARY Maximum length of attribute payload
216 * NLA_MIN_LEN Minimum length of attribute payload
217 * NLA_NESTED,
218 * NLA_NESTED_ARRAY Length verification is done by checking len of
219 * nested header (or empty); len field is used if
220 * validation_data is also used, for the max attr
221 * number in the nested policy.
222 * NLA_U8, NLA_U16,
223 * NLA_U32, NLA_U64,
224 * NLA_S8, NLA_S16,
225 * NLA_S32, NLA_S64,
226 * NLA_MSECS Leaving the length field zero will verify the
227 * given type fits, using it verifies minimum length
228 * just like "All other"
229 * NLA_BITFIELD32 Unused
230 * NLA_REJECT Unused
231 * NLA_EXACT_LEN Attribute must have exactly this length, otherwise
232 * it is rejected.
233 * NLA_EXACT_LEN_WARN Attribute should have exactly this length, a warning
234 * is logged if it is longer, shorter is rejected.
235 * NLA_MIN_LEN Minimum length of attribute payload
236 * All other Minimum length of attribute payload
237 *
238 * Meaning of `validation_data' field:
239 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and
240 * validation data must point to a u32 value of valid
241 * flags
242 * NLA_REJECT This attribute is always rejected and validation data
243 * may point to a string to report as the error instead
244 * of the generic one in extended ACK.
245 * NLA_NESTED Points to a nested policy to validate, must also set
246 * `len' to the max attribute number.
247 * Note that nla_parse() will validate, but of course not
248 * parse, the nested sub-policies.
249 * NLA_NESTED_ARRAY Points to a nested policy to validate, must also set
250 * `len' to the max attribute number. The difference to
251 * NLA_NESTED is the structure - NLA_NESTED has the
252 * nested attributes directly inside, while an array has
253 * the nested attributes at another level down and the
254 * attributes directly in the nesting don't matter.
255 * All other Unused - but note that it's a union
256 *
257 * Meaning of `min' and `max' fields, use via NLA_POLICY_MIN, NLA_POLICY_MAX
258 * and NLA_POLICY_RANGE:
259 * NLA_U8,
260 * NLA_U16,
261 * NLA_U32,
262 * NLA_U64,
263 * NLA_S8,
264 * NLA_S16,
265 * NLA_S32,
266 * NLA_S64 These are used depending on the validation_type
267 * field, if that is min/max/range then the minimum,
268 * maximum and both are used (respectively) to check
269 * the value of the integer attribute.
270 * Note that in the interest of code simplicity and
271 * struct size both limits are s16, so you cannot
272 * enforce a range that doesn't fall within the range
273 * of s16 - do that as usual in the code instead.
274 * All other Unused - but note that it's a union
275 *
276 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
277 * NLA_BINARY Validation function called for the attribute,
278 * not compatible with use of the validation_data
279 * as in NLA_BITFIELD32, NLA_REJECT, NLA_NESTED and
280 * NLA_NESTED_ARRAY.
281 * All other Unused - but note that it's a union
282 *
283 * Example:
284 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
285 * [ATTR_FOO] = { .type = NLA_U16 },
286 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
287 * [ATTR_BAZ] = { .type = NLA_EXACT_LEN, .len = sizeof(struct mystruct) },
288 * [ATTR_GOO] = { .type = NLA_BITFIELD32, .validation_data = &myvalidflags },
289 * };
290 */
291 struct nla_policy {
292 u8 type;
293 u8 validation_type;
294 u16 len;
295 union {
296 const void *validation_data;
297 struct {
298 s16 min, max;
299 };
300 int (*validate)(const struct nlattr *attr,
301 struct netlink_ext_ack *extack);
302 /* This entry is special, and used for the attribute at index 0
303 * only, and specifies special data about the policy, namely it
304 * specifies the "boundary type" where strict length validation
305 * starts for any attribute types >= this value, also, strict
306 * nesting validation starts here.
307 *
308 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
309 * for any types >= this, so need to use NLA_MIN_LEN to get the
310 * previous pure { .len = xyz } behaviour. The advantage of this
311 * is that types not specified in the policy will be rejected.
312 *
313 * For completely new families it should be set to 1 so that the
314 * validation is enforced for all attributes. For existing ones
315 * it should be set at least when new attributes are added to
316 * the enum used by the policy, and be set to the new value that
317 * was added to enforce strict validation from thereon.
318 */
319 u16 strict_start_type;
320 };
321 };
322
323 #define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len }
324 #define NLA_POLICY_EXACT_LEN_WARN(_len) { .type = NLA_EXACT_LEN_WARN, \
325 .len = _len }
326 #define NLA_POLICY_MIN_LEN(_len) { .type = NLA_MIN_LEN, .len = _len }
327
328 #define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN)
329 #define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
330
331 #define _NLA_POLICY_NESTED(maxattr, policy) \
332 { .type = NLA_NESTED, .validation_data = policy, .len = maxattr }
333 #define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
334 { .type = NLA_NESTED_ARRAY, .validation_data = policy, .len = maxattr }
335 #define NLA_POLICY_NESTED(policy) \
336 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
337 #define NLA_POLICY_NESTED_ARRAY(policy) \
338 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
339
340 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
341 #define NLA_ENSURE_INT_TYPE(tp) \
342 (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 || \
343 tp == NLA_S16 || tp == NLA_U16 || \
344 tp == NLA_S32 || tp == NLA_U32 || \
345 tp == NLA_S64 || tp == NLA_U64) + tp)
346 #define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
347 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \
348 tp != NLA_REJECT && \
349 tp != NLA_NESTED && \
350 tp != NLA_NESTED_ARRAY) + tp)
351
352 #define NLA_POLICY_RANGE(tp, _min, _max) { \
353 .type = NLA_ENSURE_INT_TYPE(tp), \
354 .validation_type = NLA_VALIDATE_RANGE, \
355 .min = _min, \
356 .max = _max \
357 }
358
359 #define NLA_POLICY_MIN(tp, _min) { \
360 .type = NLA_ENSURE_INT_TYPE(tp), \
361 .validation_type = NLA_VALIDATE_MIN, \
362 .min = _min, \
363 }
364
365 #define NLA_POLICY_MAX(tp, _max) { \
366 .type = NLA_ENSURE_INT_TYPE(tp), \
367 .validation_type = NLA_VALIDATE_MAX, \
368 .max = _max, \
369 }
370
371 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \
372 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \
373 .validation_type = NLA_VALIDATE_FUNCTION, \
374 .validate = fn, \
375 .len = __VA_ARGS__ + 0, \
376 }
377
378 /**
379 * struct nl_info - netlink source information
380 * @nlh: Netlink message header of original request
381 * @nl_net: Network namespace
382 * @portid: Netlink PORTID of requesting application
383 * @skip_notify: Skip netlink notifications to user space
384 * @skip_notify_kernel: Skip selected in-kernel notifications
385 */
386 struct nl_info {
387 struct nlmsghdr *nlh;
388 struct net *nl_net;
389 u32 portid;
390 u8 skip_notify:1,
391 skip_notify_kernel:1;
392 };
393
394 /**
395 * enum netlink_validation - netlink message/attribute validation levels
396 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
397 * extra data at the end of the message, attributes being longer than
398 * they should be, or unknown attributes being present.
399 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
400 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
401 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
402 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
403 * This can safely be set by the kernel when the given policy has no
404 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
405 * are enforced going forward.
406 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
407 * U8, U16, U32 must have exact size, etc.)
408 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
409 * and unset for other policies.
410 */
411 enum netlink_validation {
412 NL_VALIDATE_LIBERAL = 0,
413 NL_VALIDATE_TRAILING = BIT(0),
414 NL_VALIDATE_MAXTYPE = BIT(1),
415 NL_VALIDATE_UNSPEC = BIT(2),
416 NL_VALIDATE_STRICT_ATTRS = BIT(3),
417 NL_VALIDATE_NESTED = BIT(4),
418 };
419
420 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
421 NL_VALIDATE_MAXTYPE)
422 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
423 NL_VALIDATE_MAXTYPE |\
424 NL_VALIDATE_UNSPEC |\
425 NL_VALIDATE_STRICT_ATTRS |\
426 NL_VALIDATE_NESTED)
427
428 int netlink_rcv_skb(struct sk_buff *skb,
429 int (*cb)(struct sk_buff *, struct nlmsghdr *,
430 struct netlink_ext_ack *));
431 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
432 unsigned int group, int report, gfp_t flags);
433
434 int __nla_validate(const struct nlattr *head, int len, int maxtype,
435 const struct nla_policy *policy, unsigned int validate,
436 struct netlink_ext_ack *extack);
437 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
438 int len, const struct nla_policy *policy, unsigned int validate,
439 struct netlink_ext_ack *extack);
440 int nla_policy_len(const struct nla_policy *, int);
441 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
442 size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
443 char *nla_strdup(const struct nlattr *nla, gfp_t flags);
444 int nla_memcpy(void *dest, const struct nlattr *src, int count);
445 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
446 int nla_strcmp(const struct nlattr *nla, const char *str);
447 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
448 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
449 int attrlen, int padattr);
450 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
451 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
452 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
453 int attrlen, int padattr);
454 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
455 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
456 const void *data);
457 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
458 const void *data, int padattr);
459 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
460 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
461 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
462 const void *data, int padattr);
463 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
464 int nla_append(struct sk_buff *skb, int attrlen, const void *data);
465
466 /**************************************************************************
467 * Netlink Messages
468 **************************************************************************/
469
470 /**
471 * nlmsg_msg_size - length of netlink message not including padding
472 * @payload: length of message payload
473 */
474 static inline int nlmsg_msg_size(int payload)
475 {
476 return NLMSG_HDRLEN + payload;
477 }
478
479 /**
480 * nlmsg_total_size - length of netlink message including padding
481 * @payload: length of message payload
482 */
483 static inline int nlmsg_total_size(int payload)
484 {
485 return NLMSG_ALIGN(nlmsg_msg_size(payload));
486 }
487
488 /**
489 * nlmsg_padlen - length of padding at the message's tail
490 * @payload: length of message payload
491 */
492 static inline int nlmsg_padlen(int payload)
493 {
494 return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
495 }
496
497 /**
498 * nlmsg_data - head of message payload
499 * @nlh: netlink message header
500 */
501 static inline void *nlmsg_data(const struct nlmsghdr *nlh)
502 {
503 return (unsigned char *) nlh + NLMSG_HDRLEN;
504 }
505
506 /**
507 * nlmsg_len - length of message payload
508 * @nlh: netlink message header
509 */
510 static inline int nlmsg_len(const struct nlmsghdr *nlh)
511 {
512 return nlh->nlmsg_len - NLMSG_HDRLEN;
513 }
514
515 /**
516 * nlmsg_attrdata - head of attributes data
517 * @nlh: netlink message header
518 * @hdrlen: length of family specific header
519 */
520 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
521 int hdrlen)
522 {
523 unsigned char *data = nlmsg_data(nlh);
524 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
525 }
526
527 /**
528 * nlmsg_attrlen - length of attributes data
529 * @nlh: netlink message header
530 * @hdrlen: length of family specific header
531 */
532 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
533 {
534 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
535 }
536
537 /**
538 * nlmsg_ok - check if the netlink message fits into the remaining bytes
539 * @nlh: netlink message header
540 * @remaining: number of bytes remaining in message stream
541 */
542 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
543 {
544 return (remaining >= (int) sizeof(struct nlmsghdr) &&
545 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
546 nlh->nlmsg_len <= remaining);
547 }
548
549 /**
550 * nlmsg_next - next netlink message in message stream
551 * @nlh: netlink message header
552 * @remaining: number of bytes remaining in message stream
553 *
554 * Returns the next netlink message in the message stream and
555 * decrements remaining by the size of the current message.
556 */
557 static inline struct nlmsghdr *
558 nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
559 {
560 int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
561
562 *remaining -= totlen;
563
564 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
565 }
566
567 /**
568 * nla_parse - Parse a stream of attributes into a tb buffer
569 * @tb: destination array with maxtype+1 elements
570 * @maxtype: maximum attribute type to be expected
571 * @head: head of attribute stream
572 * @len: length of attribute stream
573 * @policy: validation policy
574 * @extack: extended ACK pointer
575 *
576 * Parses a stream of attributes and stores a pointer to each attribute in
577 * the tb array accessible via the attribute type. Attributes with a type
578 * exceeding maxtype will be rejected, policy must be specified, attributes
579 * will be validated in the strictest way possible.
580 *
581 * Returns 0 on success or a negative error code.
582 */
583 static inline int nla_parse(struct nlattr **tb, int maxtype,
584 const struct nlattr *head, int len,
585 const struct nla_policy *policy,
586 struct netlink_ext_ack *extack)
587 {
588 return __nla_parse(tb, maxtype, head, len, policy,
589 NL_VALIDATE_STRICT, extack);
590 }
591
592 /**
593 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
594 * @tb: destination array with maxtype+1 elements
595 * @maxtype: maximum attribute type to be expected
596 * @head: head of attribute stream
597 * @len: length of attribute stream
598 * @policy: validation policy
599 * @extack: extended ACK pointer
600 *
601 * Parses a stream of attributes and stores a pointer to each attribute in
602 * the tb array accessible via the attribute type. Attributes with a type
603 * exceeding maxtype will be ignored and attributes from the policy are not
604 * always strictly validated (only for new attributes).
605 *
606 * Returns 0 on success or a negative error code.
607 */
608 static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
609 const struct nlattr *head, int len,
610 const struct nla_policy *policy,
611 struct netlink_ext_ack *extack)
612 {
613 return __nla_parse(tb, maxtype, head, len, policy,
614 NL_VALIDATE_LIBERAL, extack);
615 }
616
617 /**
618 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
619 * @tb: destination array with maxtype+1 elements
620 * @maxtype: maximum attribute type to be expected
621 * @head: head of attribute stream
622 * @len: length of attribute stream
623 * @policy: validation policy
624 * @extack: extended ACK pointer
625 *
626 * Parses a stream of attributes and stores a pointer to each attribute in
627 * the tb array accessible via the attribute type. Attributes with a type
628 * exceeding maxtype will be rejected as well as trailing data, but the
629 * policy is not completely strictly validated (only for new attributes).
630 *
631 * Returns 0 on success or a negative error code.
632 */
633 static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
634 const struct nlattr *head,
635 int len,
636 const struct nla_policy *policy,
637 struct netlink_ext_ack *extack)
638 {
639 return __nla_parse(tb, maxtype, head, len, policy,
640 NL_VALIDATE_DEPRECATED_STRICT, extack);
641 }
642
643 /**
644 * __nlmsg_parse - parse attributes of a netlink message
645 * @nlh: netlink message header
646 * @hdrlen: length of family specific header
647 * @tb: destination array with maxtype+1 elements
648 * @maxtype: maximum attribute type to be expected
649 * @policy: validation policy
650 * @validate: validation strictness
651 * @extack: extended ACK report struct
652 *
653 * See nla_parse()
654 */
655 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
656 struct nlattr *tb[], int maxtype,
657 const struct nla_policy *policy,
658 unsigned int validate,
659 struct netlink_ext_ack *extack)
660 {
661 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
662 NL_SET_ERR_MSG(extack, "Invalid header length");
663 return -EINVAL;
664 }
665
666 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
667 nlmsg_attrlen(nlh, hdrlen), policy, validate,
668 extack);
669 }
670
671 /**
672 * nlmsg_parse - parse attributes of a netlink message
673 * @nlh: netlink message header
674 * @hdrlen: length of family specific header
675 * @tb: destination array with maxtype+1 elements
676 * @maxtype: maximum attribute type to be expected
677 * @validate: validation strictness
678 * @extack: extended ACK report struct
679 *
680 * See nla_parse()
681 */
682 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
683 struct nlattr *tb[], int maxtype,
684 const struct nla_policy *policy,
685 struct netlink_ext_ack *extack)
686 {
687 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
688 NL_VALIDATE_STRICT, extack);
689 }
690
691 /**
692 * nlmsg_parse_deprecated - parse attributes of a netlink message
693 * @nlh: netlink message header
694 * @hdrlen: length of family specific header
695 * @tb: destination array with maxtype+1 elements
696 * @maxtype: maximum attribute type to be expected
697 * @extack: extended ACK report struct
698 *
699 * See nla_parse_deprecated()
700 */
701 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
702 struct nlattr *tb[], int maxtype,
703 const struct nla_policy *policy,
704 struct netlink_ext_ack *extack)
705 {
706 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
707 NL_VALIDATE_LIBERAL, extack);
708 }
709
710 /**
711 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
712 * @nlh: netlink message header
713 * @hdrlen: length of family specific header
714 * @tb: destination array with maxtype+1 elements
715 * @maxtype: maximum attribute type to be expected
716 * @extack: extended ACK report struct
717 *
718 * See nla_parse_deprecated_strict()
719 */
720 static inline int
721 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
722 struct nlattr *tb[], int maxtype,
723 const struct nla_policy *policy,
724 struct netlink_ext_ack *extack)
725 {
726 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
727 NL_VALIDATE_DEPRECATED_STRICT, extack);
728 }
729
730 /**
731 * nlmsg_find_attr - find a specific attribute in a netlink message
732 * @nlh: netlink message header
733 * @hdrlen: length of familiy specific header
734 * @attrtype: type of attribute to look for
735 *
736 * Returns the first attribute which matches the specified type.
737 */
738 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
739 int hdrlen, int attrtype)
740 {
741 return nla_find(nlmsg_attrdata(nlh, hdrlen),
742 nlmsg_attrlen(nlh, hdrlen), attrtype);
743 }
744
745 /**
746 * nla_validate_deprecated - Validate a stream of attributes
747 * @head: head of attribute stream
748 * @len: length of attribute stream
749 * @maxtype: maximum attribute type to be expected
750 * @policy: validation policy
751 * @validate: validation strictness
752 * @extack: extended ACK report struct
753 *
754 * Validates all attributes in the specified attribute stream against the
755 * specified policy. Validation is done in liberal mode.
756 * See documenation of struct nla_policy for more details.
757 *
758 * Returns 0 on success or a negative error code.
759 */
760 static inline int nla_validate_deprecated(const struct nlattr *head, int len,
761 int maxtype,
762 const struct nla_policy *policy,
763 struct netlink_ext_ack *extack)
764 {
765 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
766 extack);
767 }
768
769 /**
770 * nla_validate - Validate a stream of attributes
771 * @head: head of attribute stream
772 * @len: length of attribute stream
773 * @maxtype: maximum attribute type to be expected
774 * @policy: validation policy
775 * @validate: validation strictness
776 * @extack: extended ACK report struct
777 *
778 * Validates all attributes in the specified attribute stream against the
779 * specified policy. Validation is done in strict mode.
780 * See documenation of struct nla_policy for more details.
781 *
782 * Returns 0 on success or a negative error code.
783 */
784 static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
785 const struct nla_policy *policy,
786 struct netlink_ext_ack *extack)
787 {
788 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
789 extack);
790 }
791
792 /**
793 * nlmsg_validate_deprecated - validate a netlink message including attributes
794 * @nlh: netlinket message header
795 * @hdrlen: length of familiy specific header
796 * @maxtype: maximum attribute type to be expected
797 * @policy: validation policy
798 * @extack: extended ACK report struct
799 */
800 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
801 int hdrlen, int maxtype,
802 const struct nla_policy *policy,
803 struct netlink_ext_ack *extack)
804 {
805 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
806 return -EINVAL;
807
808 return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
809 nlmsg_attrlen(nlh, hdrlen), maxtype,
810 policy, NL_VALIDATE_LIBERAL, extack);
811 }
812
813
814
815 /**
816 * nlmsg_report - need to report back to application?
817 * @nlh: netlink message header
818 *
819 * Returns 1 if a report back to the application is requested.
820 */
821 static inline int nlmsg_report(const struct nlmsghdr *nlh)
822 {
823 return !!(nlh->nlmsg_flags & NLM_F_ECHO);
824 }
825
826 /**
827 * nlmsg_for_each_attr - iterate over a stream of attributes
828 * @pos: loop counter, set to current attribute
829 * @nlh: netlink message header
830 * @hdrlen: length of familiy specific header
831 * @rem: initialized to len, holds bytes currently remaining in stream
832 */
833 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
834 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
835 nlmsg_attrlen(nlh, hdrlen), rem)
836
837 /**
838 * nlmsg_put - Add a new netlink message to an skb
839 * @skb: socket buffer to store message in
840 * @portid: netlink PORTID of requesting application
841 * @seq: sequence number of message
842 * @type: message type
843 * @payload: length of message payload
844 * @flags: message flags
845 *
846 * Returns NULL if the tailroom of the skb is insufficient to store
847 * the message header and payload.
848 */
849 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
850 int type, int payload, int flags)
851 {
852 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
853 return NULL;
854
855 return __nlmsg_put(skb, portid, seq, type, payload, flags);
856 }
857
858 /**
859 * nlmsg_put_answer - Add a new callback based netlink message to an skb
860 * @skb: socket buffer to store message in
861 * @cb: netlink callback
862 * @type: message type
863 * @payload: length of message payload
864 * @flags: message flags
865 *
866 * Returns NULL if the tailroom of the skb is insufficient to store
867 * the message header and payload.
868 */
869 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
870 struct netlink_callback *cb,
871 int type, int payload,
872 int flags)
873 {
874 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
875 type, payload, flags);
876 }
877
878 /**
879 * nlmsg_new - Allocate a new netlink message
880 * @payload: size of the message payload
881 * @flags: the type of memory to allocate.
882 *
883 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
884 * and a good default is needed.
885 */
886 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
887 {
888 return alloc_skb(nlmsg_total_size(payload), flags);
889 }
890
891 /**
892 * nlmsg_end - Finalize a netlink message
893 * @skb: socket buffer the message is stored in
894 * @nlh: netlink message header
895 *
896 * Corrects the netlink message header to include the appeneded
897 * attributes. Only necessary if attributes have been added to
898 * the message.
899 */
900 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
901 {
902 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
903 }
904
905 /**
906 * nlmsg_get_pos - return current position in netlink message
907 * @skb: socket buffer the message is stored in
908 *
909 * Returns a pointer to the current tail of the message.
910 */
911 static inline void *nlmsg_get_pos(struct sk_buff *skb)
912 {
913 return skb_tail_pointer(skb);
914 }
915
916 /**
917 * nlmsg_trim - Trim message to a mark
918 * @skb: socket buffer the message is stored in
919 * @mark: mark to trim to
920 *
921 * Trims the message to the provided mark.
922 */
923 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
924 {
925 if (mark) {
926 WARN_ON((unsigned char *) mark < skb->data);
927 skb_trim(skb, (unsigned char *) mark - skb->data);
928 }
929 }
930
931 /**
932 * nlmsg_cancel - Cancel construction of a netlink message
933 * @skb: socket buffer the message is stored in
934 * @nlh: netlink message header
935 *
936 * Removes the complete netlink message including all
937 * attributes from the socket buffer again.
938 */
939 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
940 {
941 nlmsg_trim(skb, nlh);
942 }
943
944 /**
945 * nlmsg_free - free a netlink message
946 * @skb: socket buffer of netlink message
947 */
948 static inline void nlmsg_free(struct sk_buff *skb)
949 {
950 kfree_skb(skb);
951 }
952
953 /**
954 * nlmsg_multicast - multicast a netlink message
955 * @sk: netlink socket to spread messages to
956 * @skb: netlink message as socket buffer
957 * @portid: own netlink portid to avoid sending to yourself
958 * @group: multicast group id
959 * @flags: allocation flags
960 */
961 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
962 u32 portid, unsigned int group, gfp_t flags)
963 {
964 int err;
965
966 NETLINK_CB(skb).dst_group = group;
967
968 err = netlink_broadcast(sk, skb, portid, group, flags);
969 if (err > 0)
970 err = 0;
971
972 return err;
973 }
974
975 /**
976 * nlmsg_unicast - unicast a netlink message
977 * @sk: netlink socket to spread message to
978 * @skb: netlink message as socket buffer
979 * @portid: netlink portid of the destination socket
980 */
981 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
982 {
983 int err;
984
985 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
986 if (err > 0)
987 err = 0;
988
989 return err;
990 }
991
992 /**
993 * nlmsg_for_each_msg - iterate over a stream of messages
994 * @pos: loop counter, set to current message
995 * @head: head of message stream
996 * @len: length of message stream
997 * @rem: initialized to len, holds bytes currently remaining in stream
998 */
999 #define nlmsg_for_each_msg(pos, head, len, rem) \
1000 for (pos = head, rem = len; \
1001 nlmsg_ok(pos, rem); \
1002 pos = nlmsg_next(pos, &(rem)))
1003
1004 /**
1005 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1006 * @cb: netlink callback structure that stores the sequence number
1007 * @nlh: netlink message header to write the flag to
1008 *
1009 * This function checks if the sequence (generation) number changed during dump
1010 * and if it did, advertises it in the netlink message header.
1011 *
1012 * The correct way to use it is to set cb->seq to the generation counter when
1013 * all locks for dumping have been acquired, and then call this function for
1014 * each message that is generated.
1015 *
1016 * Note that due to initialisation concerns, 0 is an invalid sequence number
1017 * and must not be used by code that uses this functionality.
1018 */
1019 static inline void
1020 nl_dump_check_consistent(struct netlink_callback *cb,
1021 struct nlmsghdr *nlh)
1022 {
1023 if (cb->prev_seq && cb->seq != cb->prev_seq)
1024 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1025 cb->prev_seq = cb->seq;
1026 }
1027
1028 /**************************************************************************
1029 * Netlink Attributes
1030 **************************************************************************/
1031
1032 /**
1033 * nla_attr_size - length of attribute not including padding
1034 * @payload: length of payload
1035 */
1036 static inline int nla_attr_size(int payload)
1037 {
1038 return NLA_HDRLEN + payload;
1039 }
1040
1041 /**
1042 * nla_total_size - total length of attribute including padding
1043 * @payload: length of payload
1044 */
1045 static inline int nla_total_size(int payload)
1046 {
1047 return NLA_ALIGN(nla_attr_size(payload));
1048 }
1049
1050 /**
1051 * nla_padlen - length of padding at the tail of attribute
1052 * @payload: length of payload
1053 */
1054 static inline int nla_padlen(int payload)
1055 {
1056 return nla_total_size(payload) - nla_attr_size(payload);
1057 }
1058
1059 /**
1060 * nla_type - attribute type
1061 * @nla: netlink attribute
1062 */
1063 static inline int nla_type(const struct nlattr *nla)
1064 {
1065 return nla->nla_type & NLA_TYPE_MASK;
1066 }
1067
1068 /**
1069 * nla_data - head of payload
1070 * @nla: netlink attribute
1071 */
1072 static inline void *nla_data(const struct nlattr *nla)
1073 {
1074 return (char *) nla + NLA_HDRLEN;
1075 }
1076
1077 /**
1078 * nla_len - length of payload
1079 * @nla: netlink attribute
1080 */
1081 static inline int nla_len(const struct nlattr *nla)
1082 {
1083 return nla->nla_len - NLA_HDRLEN;
1084 }
1085
1086 /**
1087 * nla_ok - check if the netlink attribute fits into the remaining bytes
1088 * @nla: netlink attribute
1089 * @remaining: number of bytes remaining in attribute stream
1090 */
1091 static inline int nla_ok(const struct nlattr *nla, int remaining)
1092 {
1093 return remaining >= (int) sizeof(*nla) &&
1094 nla->nla_len >= sizeof(*nla) &&
1095 nla->nla_len <= remaining;
1096 }
1097
1098 /**
1099 * nla_next - next netlink attribute in attribute stream
1100 * @nla: netlink attribute
1101 * @remaining: number of bytes remaining in attribute stream
1102 *
1103 * Returns the next netlink attribute in the attribute stream and
1104 * decrements remaining by the size of the current attribute.
1105 */
1106 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1107 {
1108 unsigned int totlen = NLA_ALIGN(nla->nla_len);
1109
1110 *remaining -= totlen;
1111 return (struct nlattr *) ((char *) nla + totlen);
1112 }
1113
1114 /**
1115 * nla_find_nested - find attribute in a set of nested attributes
1116 * @nla: attribute containing the nested attributes
1117 * @attrtype: type of attribute to look for
1118 *
1119 * Returns the first attribute which matches the specified type.
1120 */
1121 static inline struct nlattr *
1122 nla_find_nested(const struct nlattr *nla, int attrtype)
1123 {
1124 return nla_find(nla_data(nla), nla_len(nla), attrtype);
1125 }
1126
1127 /**
1128 * nla_parse_nested - parse nested attributes
1129 * @tb: destination array with maxtype+1 elements
1130 * @maxtype: maximum attribute type to be expected
1131 * @nla: attribute containing the nested attributes
1132 * @policy: validation policy
1133 * @extack: extended ACK report struct
1134 *
1135 * See nla_parse()
1136 */
1137 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1138 const struct nlattr *nla,
1139 const struct nla_policy *policy,
1140 struct netlink_ext_ack *extack)
1141 {
1142 if (!(nla->nla_type & NLA_F_NESTED)) {
1143 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1144 return -EINVAL;
1145 }
1146
1147 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1148 NL_VALIDATE_STRICT, extack);
1149 }
1150
1151 /**
1152 * nla_parse_nested_deprecated - parse nested attributes
1153 * @tb: destination array with maxtype+1 elements
1154 * @maxtype: maximum attribute type to be expected
1155 * @nla: attribute containing the nested attributes
1156 * @policy: validation policy
1157 * @extack: extended ACK report struct
1158 *
1159 * See nla_parse_deprecated()
1160 */
1161 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1162 const struct nlattr *nla,
1163 const struct nla_policy *policy,
1164 struct netlink_ext_ack *extack)
1165 {
1166 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1167 NL_VALIDATE_LIBERAL, extack);
1168 }
1169
1170 /**
1171 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1172 * @skb: socket buffer to add attribute to
1173 * @attrtype: attribute type
1174 * @value: numeric value
1175 */
1176 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1177 {
1178 /* temporary variables to work around GCC PR81715 with asan-stack=1 */
1179 u8 tmp = value;
1180
1181 return nla_put(skb, attrtype, sizeof(u8), &tmp);
1182 }
1183
1184 /**
1185 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1186 * @skb: socket buffer to add attribute to
1187 * @attrtype: attribute type
1188 * @value: numeric value
1189 */
1190 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1191 {
1192 u16 tmp = value;
1193
1194 return nla_put(skb, attrtype, sizeof(u16), &tmp);
1195 }
1196
1197 /**
1198 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1199 * @skb: socket buffer to add attribute to
1200 * @attrtype: attribute type
1201 * @value: numeric value
1202 */
1203 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1204 {
1205 __be16 tmp = value;
1206
1207 return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1208 }
1209
1210 /**
1211 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1212 * @skb: socket buffer to add attribute to
1213 * @attrtype: attribute type
1214 * @value: numeric value
1215 */
1216 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1217 {
1218 __be16 tmp = value;
1219
1220 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1221 }
1222
1223 /**
1224 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1225 * @skb: socket buffer to add attribute to
1226 * @attrtype: attribute type
1227 * @value: numeric value
1228 */
1229 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1230 {
1231 __le16 tmp = value;
1232
1233 return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1234 }
1235
1236 /**
1237 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1238 * @skb: socket buffer to add attribute to
1239 * @attrtype: attribute type
1240 * @value: numeric value
1241 */
1242 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1243 {
1244 u32 tmp = value;
1245
1246 return nla_put(skb, attrtype, sizeof(u32), &tmp);
1247 }
1248
1249 /**
1250 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1251 * @skb: socket buffer to add attribute to
1252 * @attrtype: attribute type
1253 * @value: numeric value
1254 */
1255 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1256 {
1257 __be32 tmp = value;
1258
1259 return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1260 }
1261
1262 /**
1263 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1264 * @skb: socket buffer to add attribute to
1265 * @attrtype: attribute type
1266 * @value: numeric value
1267 */
1268 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1269 {
1270 __be32 tmp = value;
1271
1272 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1273 }
1274
1275 /**
1276 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1277 * @skb: socket buffer to add attribute to
1278 * @attrtype: attribute type
1279 * @value: numeric value
1280 */
1281 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1282 {
1283 __le32 tmp = value;
1284
1285 return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1286 }
1287
1288 /**
1289 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1290 * @skb: socket buffer to add attribute to
1291 * @attrtype: attribute type
1292 * @value: numeric value
1293 * @padattr: attribute type for the padding
1294 */
1295 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1296 u64 value, int padattr)
1297 {
1298 u64 tmp = value;
1299
1300 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1301 }
1302
1303 /**
1304 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1305 * @skb: socket buffer to add attribute to
1306 * @attrtype: attribute type
1307 * @value: numeric value
1308 * @padattr: attribute type for the padding
1309 */
1310 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1311 int padattr)
1312 {
1313 __be64 tmp = value;
1314
1315 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1316 }
1317
1318 /**
1319 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1320 * @skb: socket buffer to add attribute to
1321 * @attrtype: attribute type
1322 * @value: numeric value
1323 * @padattr: attribute type for the padding
1324 */
1325 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1326 int padattr)
1327 {
1328 __be64 tmp = value;
1329
1330 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1331 padattr);
1332 }
1333
1334 /**
1335 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1336 * @skb: socket buffer to add attribute to
1337 * @attrtype: attribute type
1338 * @value: numeric value
1339 * @padattr: attribute type for the padding
1340 */
1341 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1342 int padattr)
1343 {
1344 __le64 tmp = value;
1345
1346 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1347 }
1348
1349 /**
1350 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1351 * @skb: socket buffer to add attribute to
1352 * @attrtype: attribute type
1353 * @value: numeric value
1354 */
1355 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1356 {
1357 s8 tmp = value;
1358
1359 return nla_put(skb, attrtype, sizeof(s8), &tmp);
1360 }
1361
1362 /**
1363 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1364 * @skb: socket buffer to add attribute to
1365 * @attrtype: attribute type
1366 * @value: numeric value
1367 */
1368 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1369 {
1370 s16 tmp = value;
1371
1372 return nla_put(skb, attrtype, sizeof(s16), &tmp);
1373 }
1374
1375 /**
1376 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1377 * @skb: socket buffer to add attribute to
1378 * @attrtype: attribute type
1379 * @value: numeric value
1380 */
1381 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1382 {
1383 s32 tmp = value;
1384
1385 return nla_put(skb, attrtype, sizeof(s32), &tmp);
1386 }
1387
1388 /**
1389 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1390 * @skb: socket buffer to add attribute to
1391 * @attrtype: attribute type
1392 * @value: numeric value
1393 * @padattr: attribute type for the padding
1394 */
1395 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1396 int padattr)
1397 {
1398 s64 tmp = value;
1399
1400 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1401 }
1402
1403 /**
1404 * nla_put_string - Add a string netlink attribute to a socket buffer
1405 * @skb: socket buffer to add attribute to
1406 * @attrtype: attribute type
1407 * @str: NUL terminated string
1408 */
1409 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1410 const char *str)
1411 {
1412 return nla_put(skb, attrtype, strlen(str) + 1, str);
1413 }
1414
1415 /**
1416 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1417 * @skb: socket buffer to add attribute to
1418 * @attrtype: attribute type
1419 */
1420 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1421 {
1422 return nla_put(skb, attrtype, 0, NULL);
1423 }
1424
1425 /**
1426 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1427 * @skb: socket buffer to add attribute to
1428 * @attrtype: attribute type
1429 * @njiffies: number of jiffies to convert to msecs
1430 * @padattr: attribute type for the padding
1431 */
1432 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1433 unsigned long njiffies, int padattr)
1434 {
1435 u64 tmp = jiffies_to_msecs(njiffies);
1436
1437 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1438 }
1439
1440 /**
1441 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1442 * buffer
1443 * @skb: socket buffer to add attribute to
1444 * @attrtype: attribute type
1445 * @addr: IPv4 address
1446 */
1447 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1448 __be32 addr)
1449 {
1450 __be32 tmp = addr;
1451
1452 return nla_put_be32(skb, attrtype, tmp);
1453 }
1454
1455 /**
1456 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1457 * buffer
1458 * @skb: socket buffer to add attribute to
1459 * @attrtype: attribute type
1460 * @addr: IPv6 address
1461 */
1462 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1463 const struct in6_addr *addr)
1464 {
1465 return nla_put(skb, attrtype, sizeof(*addr), addr);
1466 }
1467
1468 /**
1469 * nla_get_u32 - return payload of u32 attribute
1470 * @nla: u32 netlink attribute
1471 */
1472 static inline u32 nla_get_u32(const struct nlattr *nla)
1473 {
1474 return *(u32 *) nla_data(nla);
1475 }
1476
1477 /**
1478 * nla_get_be32 - return payload of __be32 attribute
1479 * @nla: __be32 netlink attribute
1480 */
1481 static inline __be32 nla_get_be32(const struct nlattr *nla)
1482 {
1483 return *(__be32 *) nla_data(nla);
1484 }
1485
1486 /**
1487 * nla_get_le32 - return payload of __le32 attribute
1488 * @nla: __le32 netlink attribute
1489 */
1490 static inline __le32 nla_get_le32(const struct nlattr *nla)
1491 {
1492 return *(__le32 *) nla_data(nla);
1493 }
1494
1495 /**
1496 * nla_get_u16 - return payload of u16 attribute
1497 * @nla: u16 netlink attribute
1498 */
1499 static inline u16 nla_get_u16(const struct nlattr *nla)
1500 {
1501 return *(u16 *) nla_data(nla);
1502 }
1503
1504 /**
1505 * nla_get_be16 - return payload of __be16 attribute
1506 * @nla: __be16 netlink attribute
1507 */
1508 static inline __be16 nla_get_be16(const struct nlattr *nla)
1509 {
1510 return *(__be16 *) nla_data(nla);
1511 }
1512
1513 /**
1514 * nla_get_le16 - return payload of __le16 attribute
1515 * @nla: __le16 netlink attribute
1516 */
1517 static inline __le16 nla_get_le16(const struct nlattr *nla)
1518 {
1519 return *(__le16 *) nla_data(nla);
1520 }
1521
1522 /**
1523 * nla_get_u8 - return payload of u8 attribute
1524 * @nla: u8 netlink attribute
1525 */
1526 static inline u8 nla_get_u8(const struct nlattr *nla)
1527 {
1528 return *(u8 *) nla_data(nla);
1529 }
1530
1531 /**
1532 * nla_get_u64 - return payload of u64 attribute
1533 * @nla: u64 netlink attribute
1534 */
1535 static inline u64 nla_get_u64(const struct nlattr *nla)
1536 {
1537 u64 tmp;
1538
1539 nla_memcpy(&tmp, nla, sizeof(tmp));
1540
1541 return tmp;
1542 }
1543
1544 /**
1545 * nla_get_be64 - return payload of __be64 attribute
1546 * @nla: __be64 netlink attribute
1547 */
1548 static inline __be64 nla_get_be64(const struct nlattr *nla)
1549 {
1550 __be64 tmp;
1551
1552 nla_memcpy(&tmp, nla, sizeof(tmp));
1553
1554 return tmp;
1555 }
1556
1557 /**
1558 * nla_get_le64 - return payload of __le64 attribute
1559 * @nla: __le64 netlink attribute
1560 */
1561 static inline __le64 nla_get_le64(const struct nlattr *nla)
1562 {
1563 return *(__le64 *) nla_data(nla);
1564 }
1565
1566 /**
1567 * nla_get_s32 - return payload of s32 attribute
1568 * @nla: s32 netlink attribute
1569 */
1570 static inline s32 nla_get_s32(const struct nlattr *nla)
1571 {
1572 return *(s32 *) nla_data(nla);
1573 }
1574
1575 /**
1576 * nla_get_s16 - return payload of s16 attribute
1577 * @nla: s16 netlink attribute
1578 */
1579 static inline s16 nla_get_s16(const struct nlattr *nla)
1580 {
1581 return *(s16 *) nla_data(nla);
1582 }
1583
1584 /**
1585 * nla_get_s8 - return payload of s8 attribute
1586 * @nla: s8 netlink attribute
1587 */
1588 static inline s8 nla_get_s8(const struct nlattr *nla)
1589 {
1590 return *(s8 *) nla_data(nla);
1591 }
1592
1593 /**
1594 * nla_get_s64 - return payload of s64 attribute
1595 * @nla: s64 netlink attribute
1596 */
1597 static inline s64 nla_get_s64(const struct nlattr *nla)
1598 {
1599 s64 tmp;
1600
1601 nla_memcpy(&tmp, nla, sizeof(tmp));
1602
1603 return tmp;
1604 }
1605
1606 /**
1607 * nla_get_flag - return payload of flag attribute
1608 * @nla: flag netlink attribute
1609 */
1610 static inline int nla_get_flag(const struct nlattr *nla)
1611 {
1612 return !!nla;
1613 }
1614
1615 /**
1616 * nla_get_msecs - return payload of msecs attribute
1617 * @nla: msecs netlink attribute
1618 *
1619 * Returns the number of milliseconds in jiffies.
1620 */
1621 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1622 {
1623 u64 msecs = nla_get_u64(nla);
1624
1625 return msecs_to_jiffies((unsigned long) msecs);
1626 }
1627
1628 /**
1629 * nla_get_in_addr - return payload of IPv4 address attribute
1630 * @nla: IPv4 address netlink attribute
1631 */
1632 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1633 {
1634 return *(__be32 *) nla_data(nla);
1635 }
1636
1637 /**
1638 * nla_get_in6_addr - return payload of IPv6 address attribute
1639 * @nla: IPv6 address netlink attribute
1640 */
1641 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1642 {
1643 struct in6_addr tmp;
1644
1645 nla_memcpy(&tmp, nla, sizeof(tmp));
1646 return tmp;
1647 }
1648
1649 /**
1650 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1651 * @nla: nla_bitfield32 attribute
1652 */
1653 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1654 {
1655 struct nla_bitfield32 tmp;
1656
1657 nla_memcpy(&tmp, nla, sizeof(tmp));
1658 return tmp;
1659 }
1660
1661 /**
1662 * nla_memdup - duplicate attribute memory (kmemdup)
1663 * @src: netlink attribute to duplicate from
1664 * @gfp: GFP mask
1665 */
1666 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1667 {
1668 return kmemdup(nla_data(src), nla_len(src), gfp);
1669 }
1670
1671 /**
1672 * nla_nest_start_noflag - Start a new level of nested attributes
1673 * @skb: socket buffer to add attributes to
1674 * @attrtype: attribute type of container
1675 *
1676 * This function exists for backward compatibility to use in APIs which never
1677 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1678 * nla_nest_start() which sets the flag.
1679 *
1680 * Returns the container attribute or NULL on error
1681 */
1682 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1683 int attrtype)
1684 {
1685 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1686
1687 if (nla_put(skb, attrtype, 0, NULL) < 0)
1688 return NULL;
1689
1690 return start;
1691 }
1692
1693 /**
1694 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1695 * @skb: socket buffer to add attributes to
1696 * @attrtype: attribute type of container
1697 *
1698 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1699 * flag. This is the preferred function to use in new code.
1700 *
1701 * Returns the container attribute or NULL on error
1702 */
1703 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1704 {
1705 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1706 }
1707
1708 /**
1709 * nla_nest_end - Finalize nesting of attributes
1710 * @skb: socket buffer the attributes are stored in
1711 * @start: container attribute
1712 *
1713 * Corrects the container attribute header to include the all
1714 * appeneded attributes.
1715 *
1716 * Returns the total data length of the skb.
1717 */
1718 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1719 {
1720 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1721 return skb->len;
1722 }
1723
1724 /**
1725 * nla_nest_cancel - Cancel nesting of attributes
1726 * @skb: socket buffer the message is stored in
1727 * @start: container attribute
1728 *
1729 * Removes the container attribute and including all nested
1730 * attributes. Returns -EMSGSIZE
1731 */
1732 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1733 {
1734 nlmsg_trim(skb, start);
1735 }
1736
1737 /**
1738 * nla_validate_nested - Validate a stream of nested attributes
1739 * @start: container attribute
1740 * @maxtype: maximum attribute type to be expected
1741 * @policy: validation policy
1742 * @validate: validation strictness
1743 * @extack: extended ACK report struct
1744 *
1745 * Validates all attributes in the nested attribute stream against the
1746 * specified policy. Attributes with a type exceeding maxtype will be
1747 * ignored. See documenation of struct nla_policy for more details.
1748 *
1749 * Returns 0 on success or a negative error code.
1750 */
1751 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1752 const struct nla_policy *policy,
1753 unsigned int validate,
1754 struct netlink_ext_ack *extack)
1755 {
1756 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1757 validate, extack);
1758 }
1759
1760 static inline int
1761 nl80211_validate_nested(const struct nlattr *start, int maxtype,
1762 const struct nla_policy *policy,
1763 struct netlink_ext_ack *extack)
1764 {
1765 return __nla_validate_nested(start, maxtype, policy,
1766 NL_VALIDATE_STRICT, extack);
1767 }
1768
1769 static inline int
1770 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1771 const struct nla_policy *policy,
1772 struct netlink_ext_ack *extack)
1773 {
1774 return __nla_validate_nested(start, maxtype, policy,
1775 NL_VALIDATE_LIBERAL, extack);
1776 }
1777
1778 /**
1779 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1780 * @skb: socket buffer the message is stored in
1781 *
1782 * Return true if padding is needed to align the next attribute (nla_data()) to
1783 * a 64-bit aligned area.
1784 */
1785 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1786 {
1787 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1788 /* The nlattr header is 4 bytes in size, that's why we test
1789 * if the skb->data _is_ aligned. A NOP attribute, plus
1790 * nlattr header for next attribute, will make nla_data()
1791 * 8-byte aligned.
1792 */
1793 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1794 return true;
1795 #endif
1796 return false;
1797 }
1798
1799 /**
1800 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1801 * @skb: socket buffer the message is stored in
1802 * @padattr: attribute type for the padding
1803 *
1804 * Conditionally emit a padding netlink attribute in order to make
1805 * the next attribute we emit have a 64-bit aligned nla_data() area.
1806 * This will only be done in architectures which do not have
1807 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1808 *
1809 * Returns zero on success or a negative error code.
1810 */
1811 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1812 {
1813 if (nla_need_padding_for_64bit(skb) &&
1814 !nla_reserve(skb, padattr, 0))
1815 return -EMSGSIZE;
1816
1817 return 0;
1818 }
1819
1820 /**
1821 * nla_total_size_64bit - total length of attribute including padding
1822 * @payload: length of payload
1823 */
1824 static inline int nla_total_size_64bit(int payload)
1825 {
1826 return NLA_ALIGN(nla_attr_size(payload))
1827 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1828 + NLA_ALIGN(nla_attr_size(0))
1829 #endif
1830 ;
1831 }
1832
1833 /**
1834 * nla_for_each_attr - iterate over a stream of attributes
1835 * @pos: loop counter, set to current attribute
1836 * @head: head of attribute stream
1837 * @len: length of attribute stream
1838 * @rem: initialized to len, holds bytes currently remaining in stream
1839 */
1840 #define nla_for_each_attr(pos, head, len, rem) \
1841 for (pos = head, rem = len; \
1842 nla_ok(pos, rem); \
1843 pos = nla_next(pos, &(rem)))
1844
1845 /**
1846 * nla_for_each_nested - iterate over nested attributes
1847 * @pos: loop counter, set to current attribute
1848 * @nla: attribute containing the nested attributes
1849 * @rem: initialized to len, holds bytes currently remaining in stream
1850 */
1851 #define nla_for_each_nested(pos, nla, rem) \
1852 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1853
1854 /**
1855 * nla_is_last - Test if attribute is last in stream
1856 * @nla: attribute to test
1857 * @rem: bytes remaining in stream
1858 */
1859 static inline bool nla_is_last(const struct nlattr *nla, int rem)
1860 {
1861 return nla->nla_len == rem;
1862 }
1863
1864 #endif