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