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 || tp == NLA_U64)
380 #define __NLA_IS_SINT_TYPE(tp)						\
381 	(tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64)
382 #define __NLA_IS_BEINT_TYPE(tp)						\
383 	(tp == NLA_BE16 || tp == NLA_BE32)
384 
385 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
386 #define NLA_ENSURE_UINT_TYPE(tp)			\
387 	(__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
388 #define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp)		\
389 	(__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) ||	\
390 		      tp == NLA_MSECS ||		\
391 		      tp == NLA_BINARY) + tp)
392 #define NLA_ENSURE_SINT_TYPE(tp)			\
393 	(__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
394 #define NLA_ENSURE_INT_OR_BINARY_TYPE(tp)		\
395 	(__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) ||		\
396 		      __NLA_IS_SINT_TYPE(tp) ||		\
397 		      __NLA_IS_BEINT_TYPE(tp) ||	\
398 		      tp == NLA_MSECS ||		\
399 		      tp == NLA_BINARY) + tp)
400 #define NLA_ENSURE_NO_VALIDATION_PTR(tp)		\
401 	(__NLA_ENSURE(tp != NLA_BITFIELD32 &&		\
402 		      tp != NLA_REJECT &&		\
403 		      tp != NLA_NESTED &&		\
404 		      tp != NLA_NESTED_ARRAY) + tp)
405 #define NLA_ENSURE_BEINT_TYPE(tp)			\
406 	(__NLA_ENSURE(__NLA_IS_BEINT_TYPE(tp)) + tp)
407 
408 #define NLA_POLICY_RANGE(tp, _min, _max) {		\
409 	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
410 	.validation_type = NLA_VALIDATE_RANGE,		\
411 	.min = _min,					\
412 	.max = _max					\
413 }
414 
415 #define NLA_POLICY_FULL_RANGE(tp, _range) {		\
416 	.type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp),	\
417 	.validation_type = NLA_VALIDATE_RANGE_PTR,	\
418 	.range = _range,				\
419 }
420 
421 #define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) {	\
422 	.type = NLA_ENSURE_SINT_TYPE(tp),		\
423 	.validation_type = NLA_VALIDATE_RANGE_PTR,	\
424 	.range_signed = _range,				\
425 }
426 
427 #define NLA_POLICY_MIN(tp, _min) {			\
428 	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
429 	.validation_type = NLA_VALIDATE_MIN,		\
430 	.min = _min,					\
431 }
432 
433 #define NLA_POLICY_MAX(tp, _max) {			\
434 	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
435 	.validation_type = NLA_VALIDATE_MAX,		\
436 	.max = _max,					\
437 }
438 
439 #define NLA_POLICY_MASK(tp, _mask) {			\
440 	.type = NLA_ENSURE_UINT_TYPE(tp),		\
441 	.validation_type = NLA_VALIDATE_MASK,		\
442 	.mask = _mask,					\
443 }
444 
445 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) {		\
446 	.type = NLA_ENSURE_NO_VALIDATION_PTR(tp),	\
447 	.validation_type = NLA_VALIDATE_FUNCTION,	\
448 	.validate = fn,					\
449 	.len = __VA_ARGS__ + 0,				\
450 }
451 
452 #define NLA_POLICY_EXACT_LEN(_len)	NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
453 #define NLA_POLICY_EXACT_LEN_WARN(_len) {			\
454 	.type = NLA_BINARY,					\
455 	.validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG,	\
456 	.min = _len,						\
457 	.max = _len						\
458 }
459 #define NLA_POLICY_MIN_LEN(_len)	NLA_POLICY_MIN(NLA_BINARY, _len)
460 
461 /**
462  * struct nl_info - netlink source information
463  * @nlh: Netlink message header of original request
464  * @nl_net: Network namespace
465  * @portid: Netlink PORTID of requesting application
466  * @skip_notify: Skip netlink notifications to user space
467  * @skip_notify_kernel: Skip selected in-kernel notifications
468  */
469 struct nl_info {
470 	struct nlmsghdr		*nlh;
471 	struct net		*nl_net;
472 	u32			portid;
473 	u8			skip_notify:1,
474 				skip_notify_kernel:1;
475 };
476 
477 /**
478  * enum netlink_validation - netlink message/attribute validation levels
479  * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
480  *	extra data at the end of the message, attributes being longer than
481  *	they should be, or unknown attributes being present.
482  * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
483  * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
484  *	this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
485  * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
486  *	This can safely be set by the kernel when the given policy has no
487  *	NLA_UNSPEC anymore, and can thus be used to ensure policy entries
488  *	are enforced going forward.
489  * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
490  *	U8, U16, U32 must have exact size, etc.)
491  * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
492  *	and unset for other policies.
493  */
494 enum netlink_validation {
495 	NL_VALIDATE_LIBERAL = 0,
496 	NL_VALIDATE_TRAILING = BIT(0),
497 	NL_VALIDATE_MAXTYPE = BIT(1),
498 	NL_VALIDATE_UNSPEC = BIT(2),
499 	NL_VALIDATE_STRICT_ATTRS = BIT(3),
500 	NL_VALIDATE_NESTED = BIT(4),
501 };
502 
503 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
504 				       NL_VALIDATE_MAXTYPE)
505 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
506 			    NL_VALIDATE_MAXTYPE |\
507 			    NL_VALIDATE_UNSPEC |\
508 			    NL_VALIDATE_STRICT_ATTRS |\
509 			    NL_VALIDATE_NESTED)
510 
511 int netlink_rcv_skb(struct sk_buff *skb,
512 		    int (*cb)(struct sk_buff *, struct nlmsghdr *,
513 			      struct netlink_ext_ack *));
514 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
515 		 unsigned int group, int report, gfp_t flags);
516 
517 int __nla_validate(const struct nlattr *head, int len, int maxtype,
518 		   const struct nla_policy *policy, unsigned int validate,
519 		   struct netlink_ext_ack *extack);
520 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
521 		int len, const struct nla_policy *policy, unsigned int validate,
522 		struct netlink_ext_ack *extack);
523 int nla_policy_len(const struct nla_policy *, int);
524 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
525 ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
526 char *nla_strdup(const struct nlattr *nla, gfp_t flags);
527 int nla_memcpy(void *dest, const struct nlattr *src, int count);
528 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
529 int nla_strcmp(const struct nlattr *nla, const char *str);
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 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
535 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
536 				 int attrlen, int padattr);
537 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
538 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
539 	       const void *data);
540 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
541 		     const void *data, int padattr);
542 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
543 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
544 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
545 		  const void *data, int padattr);
546 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
547 int nla_append(struct sk_buff *skb, int attrlen, const void *data);
548 
549 /**************************************************************************
550  * Netlink Messages
551  **************************************************************************/
552 
553 /**
554  * nlmsg_msg_size - length of netlink message not including padding
555  * @payload: length of message payload
556  */
nlmsg_msg_size(int payload)557 static inline int nlmsg_msg_size(int payload)
558 {
559 	return NLMSG_HDRLEN + payload;
560 }
561 
562 /**
563  * nlmsg_total_size - length of netlink message including padding
564  * @payload: length of message payload
565  */
nlmsg_total_size(int payload)566 static inline int nlmsg_total_size(int payload)
567 {
568 	return NLMSG_ALIGN(nlmsg_msg_size(payload));
569 }
570 
571 /**
572  * nlmsg_padlen - length of padding at the message's tail
573  * @payload: length of message payload
574  */
nlmsg_padlen(int payload)575 static inline int nlmsg_padlen(int payload)
576 {
577 	return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
578 }
579 
580 /**
581  * nlmsg_data - head of message payload
582  * @nlh: netlink message header
583  */
nlmsg_data(const struct nlmsghdr * nlh)584 static inline void *nlmsg_data(const struct nlmsghdr *nlh)
585 {
586 	return (unsigned char *) nlh + NLMSG_HDRLEN;
587 }
588 
589 /**
590  * nlmsg_len - length of message payload
591  * @nlh: netlink message header
592  */
nlmsg_len(const struct nlmsghdr * nlh)593 static inline int nlmsg_len(const struct nlmsghdr *nlh)
594 {
595 	return nlh->nlmsg_len - NLMSG_HDRLEN;
596 }
597 
598 /**
599  * nlmsg_attrdata - head of attributes data
600  * @nlh: netlink message header
601  * @hdrlen: length of family specific header
602  */
nlmsg_attrdata(const struct nlmsghdr * nlh,int hdrlen)603 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
604 					    int hdrlen)
605 {
606 	unsigned char *data = nlmsg_data(nlh);
607 	return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
608 }
609 
610 /**
611  * nlmsg_attrlen - length of attributes data
612  * @nlh: netlink message header
613  * @hdrlen: length of family specific header
614  */
nlmsg_attrlen(const struct nlmsghdr * nlh,int hdrlen)615 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
616 {
617 	return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
618 }
619 
620 /**
621  * nlmsg_ok - check if the netlink message fits into the remaining bytes
622  * @nlh: netlink message header
623  * @remaining: number of bytes remaining in message stream
624  */
nlmsg_ok(const struct nlmsghdr * nlh,int remaining)625 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
626 {
627 	return (remaining >= (int) sizeof(struct nlmsghdr) &&
628 		nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
629 		nlh->nlmsg_len <= remaining);
630 }
631 
632 /**
633  * nlmsg_next - next netlink message in message stream
634  * @nlh: netlink message header
635  * @remaining: number of bytes remaining in message stream
636  *
637  * Returns the next netlink message in the message stream and
638  * decrements remaining by the size of the current message.
639  */
640 static inline struct nlmsghdr *
nlmsg_next(const struct nlmsghdr * nlh,int * remaining)641 nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
642 {
643 	int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
644 
645 	*remaining -= totlen;
646 
647 	return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
648 }
649 
650 /**
651  * nla_parse - Parse a stream of attributes into a tb buffer
652  * @tb: destination array with maxtype+1 elements
653  * @maxtype: maximum attribute type to be expected
654  * @head: head of attribute stream
655  * @len: length of attribute stream
656  * @policy: validation policy
657  * @extack: extended ACK pointer
658  *
659  * Parses a stream of attributes and stores a pointer to each attribute in
660  * the tb array accessible via the attribute type. Attributes with a type
661  * exceeding maxtype will be rejected, policy must be specified, attributes
662  * will be validated in the strictest way possible.
663  *
664  * Returns 0 on success or a negative error code.
665  */
nla_parse(struct nlattr ** tb,int maxtype,const struct nlattr * head,int len,const struct nla_policy * policy,struct netlink_ext_ack * extack)666 static inline int nla_parse(struct nlattr **tb, int maxtype,
667 			    const struct nlattr *head, int len,
668 			    const struct nla_policy *policy,
669 			    struct netlink_ext_ack *extack)
670 {
671 	return __nla_parse(tb, maxtype, head, len, policy,
672 			   NL_VALIDATE_STRICT, extack);
673 }
674 
675 /**
676  * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
677  * @tb: destination array with maxtype+1 elements
678  * @maxtype: maximum attribute type to be expected
679  * @head: head of attribute stream
680  * @len: length of attribute stream
681  * @policy: validation policy
682  * @extack: extended ACK pointer
683  *
684  * Parses a stream of attributes and stores a pointer to each attribute in
685  * the tb array accessible via the attribute type. Attributes with a type
686  * exceeding maxtype will be ignored and attributes from the policy are not
687  * always strictly validated (only for new attributes).
688  *
689  * Returns 0 on success or a negative error code.
690  */
nla_parse_deprecated(struct nlattr ** tb,int maxtype,const struct nlattr * head,int len,const struct nla_policy * policy,struct netlink_ext_ack * extack)691 static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
692 				       const struct nlattr *head, int len,
693 				       const struct nla_policy *policy,
694 				       struct netlink_ext_ack *extack)
695 {
696 	return __nla_parse(tb, maxtype, head, len, policy,
697 			   NL_VALIDATE_LIBERAL, extack);
698 }
699 
700 /**
701  * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
702  * @tb: destination array with maxtype+1 elements
703  * @maxtype: maximum attribute type to be expected
704  * @head: head of attribute stream
705  * @len: length of attribute stream
706  * @policy: validation policy
707  * @extack: extended ACK pointer
708  *
709  * Parses a stream of attributes and stores a pointer to each attribute in
710  * the tb array accessible via the attribute type. Attributes with a type
711  * exceeding maxtype will be rejected as well as trailing data, but the
712  * policy is not completely strictly validated (only for new attributes).
713  *
714  * Returns 0 on success or a negative error code.
715  */
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)716 static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
717 					      const struct nlattr *head,
718 					      int len,
719 					      const struct nla_policy *policy,
720 					      struct netlink_ext_ack *extack)
721 {
722 	return __nla_parse(tb, maxtype, head, len, policy,
723 			   NL_VALIDATE_DEPRECATED_STRICT, extack);
724 }
725 
726 /**
727  * __nlmsg_parse - parse attributes of a netlink message
728  * @nlh: netlink message header
729  * @hdrlen: length of family specific header
730  * @tb: destination array with maxtype+1 elements
731  * @maxtype: maximum attribute type to be expected
732  * @policy: validation policy
733  * @validate: validation strictness
734  * @extack: extended ACK report struct
735  *
736  * See nla_parse()
737  */
__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)738 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
739 				struct nlattr *tb[], int maxtype,
740 				const struct nla_policy *policy,
741 				unsigned int validate,
742 				struct netlink_ext_ack *extack)
743 {
744 	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
745 		NL_SET_ERR_MSG(extack, "Invalid header length");
746 		return -EINVAL;
747 	}
748 
749 	return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
750 			   nlmsg_attrlen(nlh, hdrlen), policy, validate,
751 			   extack);
752 }
753 
754 /**
755  * nlmsg_parse - parse attributes of a netlink message
756  * @nlh: netlink message header
757  * @hdrlen: length of family specific header
758  * @tb: destination array with maxtype+1 elements
759  * @maxtype: maximum attribute type to be expected
760  * @policy: validation policy
761  * @extack: extended ACK report struct
762  *
763  * See nla_parse()
764  */
nlmsg_parse(const struct nlmsghdr * nlh,int hdrlen,struct nlattr * tb[],int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)765 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
766 			      struct nlattr *tb[], int maxtype,
767 			      const struct nla_policy *policy,
768 			      struct netlink_ext_ack *extack)
769 {
770 	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
771 			     NL_VALIDATE_STRICT, extack);
772 }
773 
774 /**
775  * nlmsg_parse_deprecated - parse attributes of a netlink message
776  * @nlh: netlink message header
777  * @hdrlen: length of family specific header
778  * @tb: destination array with maxtype+1 elements
779  * @maxtype: maximum attribute type to be expected
780  * @policy: validation policy
781  * @extack: extended ACK report struct
782  *
783  * See nla_parse_deprecated()
784  */
nlmsg_parse_deprecated(const struct nlmsghdr * nlh,int hdrlen,struct nlattr * tb[],int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)785 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
786 					 struct nlattr *tb[], int maxtype,
787 					 const struct nla_policy *policy,
788 					 struct netlink_ext_ack *extack)
789 {
790 	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
791 			     NL_VALIDATE_LIBERAL, extack);
792 }
793 
794 /**
795  * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
796  * @nlh: netlink message header
797  * @hdrlen: length of family specific header
798  * @tb: destination array with maxtype+1 elements
799  * @maxtype: maximum attribute type to be expected
800  * @policy: validation policy
801  * @extack: extended ACK report struct
802  *
803  * See nla_parse_deprecated_strict()
804  */
805 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)806 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
807 			      struct nlattr *tb[], int maxtype,
808 			      const struct nla_policy *policy,
809 			      struct netlink_ext_ack *extack)
810 {
811 	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
812 			     NL_VALIDATE_DEPRECATED_STRICT, extack);
813 }
814 
815 /**
816  * nlmsg_find_attr - find a specific attribute in a netlink message
817  * @nlh: netlink message header
818  * @hdrlen: length of familiy specific header
819  * @attrtype: type of attribute to look for
820  *
821  * Returns the first attribute which matches the specified type.
822  */
nlmsg_find_attr(const struct nlmsghdr * nlh,int hdrlen,int attrtype)823 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
824 					     int hdrlen, int attrtype)
825 {
826 	return nla_find(nlmsg_attrdata(nlh, hdrlen),
827 			nlmsg_attrlen(nlh, hdrlen), attrtype);
828 }
829 
830 /**
831  * nla_validate_deprecated - Validate a stream of attributes
832  * @head: head of attribute stream
833  * @len: length of attribute stream
834  * @maxtype: maximum attribute type to be expected
835  * @policy: validation policy
836  * @extack: extended ACK report struct
837  *
838  * Validates all attributes in the specified attribute stream against the
839  * specified policy. Validation is done in liberal mode.
840  * See documenation of struct nla_policy for more details.
841  *
842  * Returns 0 on success or a negative error code.
843  */
nla_validate_deprecated(const struct nlattr * head,int len,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)844 static inline int nla_validate_deprecated(const struct nlattr *head, int len,
845 					  int maxtype,
846 					  const struct nla_policy *policy,
847 					  struct netlink_ext_ack *extack)
848 {
849 	return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
850 			      extack);
851 }
852 
853 /**
854  * nla_validate - Validate a stream of attributes
855  * @head: head of attribute stream
856  * @len: length of attribute stream
857  * @maxtype: maximum attribute type to be expected
858  * @policy: validation policy
859  * @extack: extended ACK report struct
860  *
861  * Validates all attributes in the specified attribute stream against the
862  * specified policy. Validation is done in strict mode.
863  * See documenation of struct nla_policy for more details.
864  *
865  * Returns 0 on success or a negative error code.
866  */
nla_validate(const struct nlattr * head,int len,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)867 static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
868 			       const struct nla_policy *policy,
869 			       struct netlink_ext_ack *extack)
870 {
871 	return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
872 			      extack);
873 }
874 
875 /**
876  * nlmsg_validate_deprecated - validate a netlink message including attributes
877  * @nlh: netlinket message header
878  * @hdrlen: length of familiy specific header
879  * @maxtype: maximum attribute type to be expected
880  * @policy: validation policy
881  * @extack: extended ACK report struct
882  */
nlmsg_validate_deprecated(const struct nlmsghdr * nlh,int hdrlen,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)883 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
884 					    int hdrlen, int maxtype,
885 					    const struct nla_policy *policy,
886 					    struct netlink_ext_ack *extack)
887 {
888 	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
889 		return -EINVAL;
890 
891 	return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
892 			      nlmsg_attrlen(nlh, hdrlen), maxtype,
893 			      policy, NL_VALIDATE_LIBERAL, extack);
894 }
895 
896 
897 
898 /**
899  * nlmsg_report - need to report back to application?
900  * @nlh: netlink message header
901  *
902  * Returns 1 if a report back to the application is requested.
903  */
nlmsg_report(const struct nlmsghdr * nlh)904 static inline int nlmsg_report(const struct nlmsghdr *nlh)
905 {
906 	return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
907 }
908 
909 /**
910  * nlmsg_seq - return the seq number of netlink message
911  * @nlh: netlink message header
912  *
913  * Returns 0 if netlink message is NULL
914  */
nlmsg_seq(const struct nlmsghdr * nlh)915 static inline u32 nlmsg_seq(const struct nlmsghdr *nlh)
916 {
917 	return nlh ? nlh->nlmsg_seq : 0;
918 }
919 
920 /**
921  * nlmsg_for_each_attr - iterate over a stream of attributes
922  * @pos: loop counter, set to current attribute
923  * @nlh: netlink message header
924  * @hdrlen: length of familiy specific header
925  * @rem: initialized to len, holds bytes currently remaining in stream
926  */
927 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
928 	nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
929 			  nlmsg_attrlen(nlh, hdrlen), rem)
930 
931 /**
932  * nlmsg_put - Add a new netlink message to an skb
933  * @skb: socket buffer to store message in
934  * @portid: netlink PORTID of requesting application
935  * @seq: sequence number of message
936  * @type: message type
937  * @payload: length of message payload
938  * @flags: message flags
939  *
940  * Returns NULL if the tailroom of the skb is insufficient to store
941  * the message header and payload.
942  */
nlmsg_put(struct sk_buff * skb,u32 portid,u32 seq,int type,int payload,int flags)943 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
944 					 int type, int payload, int flags)
945 {
946 	if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
947 		return NULL;
948 
949 	return __nlmsg_put(skb, portid, seq, type, payload, flags);
950 }
951 
952 /**
953  * nlmsg_append - Add more data to a nlmsg in a skb
954  * @skb: socket buffer to store message in
955  * @size: length of message payload
956  *
957  * Append data to an existing nlmsg, used when constructing a message
958  * with multiple fixed-format headers (which is rare).
959  * Returns NULL if the tailroom of the skb is insufficient to store
960  * the extra payload.
961  */
nlmsg_append(struct sk_buff * skb,u32 size)962 static inline void *nlmsg_append(struct sk_buff *skb, u32 size)
963 {
964 	if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size)))
965 		return NULL;
966 
967 	if (NLMSG_ALIGN(size) - size)
968 		memset(skb_tail_pointer(skb) + size, 0,
969 		       NLMSG_ALIGN(size) - size);
970 	return __skb_put(skb, NLMSG_ALIGN(size));
971 }
972 
973 /**
974  * nlmsg_put_answer - Add a new callback based netlink message to an skb
975  * @skb: socket buffer to store message in
976  * @cb: netlink callback
977  * @type: message type
978  * @payload: length of message payload
979  * @flags: message flags
980  *
981  * Returns NULL if the tailroom of the skb is insufficient to store
982  * the message header and payload.
983  */
nlmsg_put_answer(struct sk_buff * skb,struct netlink_callback * cb,int type,int payload,int flags)984 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
985 						struct netlink_callback *cb,
986 						int type, int payload,
987 						int flags)
988 {
989 	return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
990 			 type, payload, flags);
991 }
992 
993 /**
994  * nlmsg_new - Allocate a new netlink message
995  * @payload: size of the message payload
996  * @flags: the type of memory to allocate.
997  *
998  * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
999  * and a good default is needed.
1000  */
nlmsg_new(size_t payload,gfp_t flags)1001 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
1002 {
1003 	return alloc_skb(nlmsg_total_size(payload), flags);
1004 }
1005 
1006 /**
1007  * nlmsg_end - Finalize a netlink message
1008  * @skb: socket buffer the message is stored in
1009  * @nlh: netlink message header
1010  *
1011  * Corrects the netlink message header to include the appeneded
1012  * attributes. Only necessary if attributes have been added to
1013  * the message.
1014  */
nlmsg_end(struct sk_buff * skb,struct nlmsghdr * nlh)1015 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
1016 {
1017 	nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
1018 }
1019 
1020 /**
1021  * nlmsg_get_pos - return current position in netlink message
1022  * @skb: socket buffer the message is stored in
1023  *
1024  * Returns a pointer to the current tail of the message.
1025  */
nlmsg_get_pos(struct sk_buff * skb)1026 static inline void *nlmsg_get_pos(struct sk_buff *skb)
1027 {
1028 	return skb_tail_pointer(skb);
1029 }
1030 
1031 /**
1032  * nlmsg_trim - Trim message to a mark
1033  * @skb: socket buffer the message is stored in
1034  * @mark: mark to trim to
1035  *
1036  * Trims the message to the provided mark.
1037  */
nlmsg_trim(struct sk_buff * skb,const void * mark)1038 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1039 {
1040 	if (mark) {
1041 		WARN_ON((unsigned char *) mark < skb->data);
1042 		skb_trim(skb, (unsigned char *) mark - skb->data);
1043 	}
1044 }
1045 
1046 /**
1047  * nlmsg_cancel - Cancel construction of a netlink message
1048  * @skb: socket buffer the message is stored in
1049  * @nlh: netlink message header
1050  *
1051  * Removes the complete netlink message including all
1052  * attributes from the socket buffer again.
1053  */
nlmsg_cancel(struct sk_buff * skb,struct nlmsghdr * nlh)1054 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1055 {
1056 	nlmsg_trim(skb, nlh);
1057 }
1058 
1059 /**
1060  * nlmsg_free - free a netlink message
1061  * @skb: socket buffer of netlink message
1062  */
nlmsg_free(struct sk_buff * skb)1063 static inline void nlmsg_free(struct sk_buff *skb)
1064 {
1065 	kfree_skb(skb);
1066 }
1067 
1068 /**
1069  * nlmsg_multicast - multicast a netlink message
1070  * @sk: netlink socket to spread messages to
1071  * @skb: netlink message as socket buffer
1072  * @portid: own netlink portid to avoid sending to yourself
1073  * @group: multicast group id
1074  * @flags: allocation flags
1075  */
nlmsg_multicast(struct sock * sk,struct sk_buff * skb,u32 portid,unsigned int group,gfp_t flags)1076 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1077 				  u32 portid, unsigned int group, gfp_t flags)
1078 {
1079 	int err;
1080 
1081 	NETLINK_CB(skb).dst_group = group;
1082 
1083 	err = netlink_broadcast(sk, skb, portid, group, flags);
1084 	if (err > 0)
1085 		err = 0;
1086 
1087 	return err;
1088 }
1089 
1090 /**
1091  * nlmsg_unicast - unicast a netlink message
1092  * @sk: netlink socket to spread message to
1093  * @skb: netlink message as socket buffer
1094  * @portid: netlink portid of the destination socket
1095  */
nlmsg_unicast(struct sock * sk,struct sk_buff * skb,u32 portid)1096 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1097 {
1098 	int err;
1099 
1100 	err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1101 	if (err > 0)
1102 		err = 0;
1103 
1104 	return err;
1105 }
1106 
1107 /**
1108  * nlmsg_for_each_msg - iterate over a stream of messages
1109  * @pos: loop counter, set to current message
1110  * @head: head of message stream
1111  * @len: length of message stream
1112  * @rem: initialized to len, holds bytes currently remaining in stream
1113  */
1114 #define nlmsg_for_each_msg(pos, head, len, rem) \
1115 	for (pos = head, rem = len; \
1116 	     nlmsg_ok(pos, rem); \
1117 	     pos = nlmsg_next(pos, &(rem)))
1118 
1119 /**
1120  * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1121  * @cb: netlink callback structure that stores the sequence number
1122  * @nlh: netlink message header to write the flag to
1123  *
1124  * This function checks if the sequence (generation) number changed during dump
1125  * and if it did, advertises it in the netlink message header.
1126  *
1127  * The correct way to use it is to set cb->seq to the generation counter when
1128  * all locks for dumping have been acquired, and then call this function for
1129  * each message that is generated.
1130  *
1131  * Note that due to initialisation concerns, 0 is an invalid sequence number
1132  * and must not be used by code that uses this functionality.
1133  */
1134 static inline void
nl_dump_check_consistent(struct netlink_callback * cb,struct nlmsghdr * nlh)1135 nl_dump_check_consistent(struct netlink_callback *cb,
1136 			 struct nlmsghdr *nlh)
1137 {
1138 	if (cb->prev_seq && cb->seq != cb->prev_seq)
1139 		nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1140 	cb->prev_seq = cb->seq;
1141 }
1142 
1143 /**************************************************************************
1144  * Netlink Attributes
1145  **************************************************************************/
1146 
1147 /**
1148  * nla_attr_size - length of attribute not including padding
1149  * @payload: length of payload
1150  */
nla_attr_size(int payload)1151 static inline int nla_attr_size(int payload)
1152 {
1153 	return NLA_HDRLEN + payload;
1154 }
1155 
1156 /**
1157  * nla_total_size - total length of attribute including padding
1158  * @payload: length of payload
1159  */
nla_total_size(int payload)1160 static inline int nla_total_size(int payload)
1161 {
1162 	return NLA_ALIGN(nla_attr_size(payload));
1163 }
1164 
1165 /**
1166  * nla_padlen - length of padding at the tail of attribute
1167  * @payload: length of payload
1168  */
nla_padlen(int payload)1169 static inline int nla_padlen(int payload)
1170 {
1171 	return nla_total_size(payload) - nla_attr_size(payload);
1172 }
1173 
1174 /**
1175  * nla_type - attribute type
1176  * @nla: netlink attribute
1177  */
nla_type(const struct nlattr * nla)1178 static inline int nla_type(const struct nlattr *nla)
1179 {
1180 	return nla->nla_type & NLA_TYPE_MASK;
1181 }
1182 
1183 /**
1184  * nla_data - head of payload
1185  * @nla: netlink attribute
1186  */
nla_data(const struct nlattr * nla)1187 static inline void *nla_data(const struct nlattr *nla)
1188 {
1189 	return (char *) nla + NLA_HDRLEN;
1190 }
1191 
1192 /**
1193  * nla_len - length of payload
1194  * @nla: netlink attribute
1195  */
nla_len(const struct nlattr * nla)1196 static inline int nla_len(const struct nlattr *nla)
1197 {
1198 	return nla->nla_len - NLA_HDRLEN;
1199 }
1200 
1201 /**
1202  * nla_ok - check if the netlink attribute fits into the remaining bytes
1203  * @nla: netlink attribute
1204  * @remaining: number of bytes remaining in attribute stream
1205  */
nla_ok(const struct nlattr * nla,int remaining)1206 static inline int nla_ok(const struct nlattr *nla, int remaining)
1207 {
1208 	return remaining >= (int) sizeof(*nla) &&
1209 	       nla->nla_len >= sizeof(*nla) &&
1210 	       nla->nla_len <= remaining;
1211 }
1212 
1213 /**
1214  * nla_next - next netlink attribute in attribute stream
1215  * @nla: netlink attribute
1216  * @remaining: number of bytes remaining in attribute stream
1217  *
1218  * Returns the next netlink attribute in the attribute stream and
1219  * decrements remaining by the size of the current attribute.
1220  */
nla_next(const struct nlattr * nla,int * remaining)1221 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1222 {
1223 	unsigned int totlen = NLA_ALIGN(nla->nla_len);
1224 
1225 	*remaining -= totlen;
1226 	return (struct nlattr *) ((char *) nla + totlen);
1227 }
1228 
1229 /**
1230  * nla_find_nested - find attribute in a set of nested attributes
1231  * @nla: attribute containing the nested attributes
1232  * @attrtype: type of attribute to look for
1233  *
1234  * Returns the first attribute which matches the specified type.
1235  */
1236 static inline struct nlattr *
nla_find_nested(const struct nlattr * nla,int attrtype)1237 nla_find_nested(const struct nlattr *nla, int attrtype)
1238 {
1239 	return nla_find(nla_data(nla), nla_len(nla), attrtype);
1240 }
1241 
1242 /**
1243  * nla_parse_nested - parse nested attributes
1244  * @tb: destination array with maxtype+1 elements
1245  * @maxtype: maximum attribute type to be expected
1246  * @nla: attribute containing the nested attributes
1247  * @policy: validation policy
1248  * @extack: extended ACK report struct
1249  *
1250  * See nla_parse()
1251  */
nla_parse_nested(struct nlattr * tb[],int maxtype,const struct nlattr * nla,const struct nla_policy * policy,struct netlink_ext_ack * extack)1252 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1253 				   const struct nlattr *nla,
1254 				   const struct nla_policy *policy,
1255 				   struct netlink_ext_ack *extack)
1256 {
1257 	if (!(nla->nla_type & NLA_F_NESTED)) {
1258 		NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1259 		return -EINVAL;
1260 	}
1261 
1262 	return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1263 			   NL_VALIDATE_STRICT, extack);
1264 }
1265 
1266 /**
1267  * nla_parse_nested_deprecated - parse nested attributes
1268  * @tb: destination array with maxtype+1 elements
1269  * @maxtype: maximum attribute type to be expected
1270  * @nla: attribute containing the nested attributes
1271  * @policy: validation policy
1272  * @extack: extended ACK report struct
1273  *
1274  * See nla_parse_deprecated()
1275  */
nla_parse_nested_deprecated(struct nlattr * tb[],int maxtype,const struct nlattr * nla,const struct nla_policy * policy,struct netlink_ext_ack * extack)1276 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1277 					      const struct nlattr *nla,
1278 					      const struct nla_policy *policy,
1279 					      struct netlink_ext_ack *extack)
1280 {
1281 	return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1282 			   NL_VALIDATE_LIBERAL, extack);
1283 }
1284 
1285 /**
1286  * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1287  * @skb: socket buffer to add attribute to
1288  * @attrtype: attribute type
1289  * @value: numeric value
1290  */
nla_put_u8(struct sk_buff * skb,int attrtype,u8 value)1291 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1292 {
1293 	/* temporary variables to work around GCC PR81715 with asan-stack=1 */
1294 	u8 tmp = value;
1295 
1296 	return nla_put(skb, attrtype, sizeof(u8), &tmp);
1297 }
1298 
1299 /**
1300  * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1301  * @skb: socket buffer to add attribute to
1302  * @attrtype: attribute type
1303  * @value: numeric value
1304  */
nla_put_u16(struct sk_buff * skb,int attrtype,u16 value)1305 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1306 {
1307 	u16 tmp = value;
1308 
1309 	return nla_put(skb, attrtype, sizeof(u16), &tmp);
1310 }
1311 
1312 /**
1313  * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1314  * @skb: socket buffer to add attribute to
1315  * @attrtype: attribute type
1316  * @value: numeric value
1317  */
nla_put_be16(struct sk_buff * skb,int attrtype,__be16 value)1318 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1319 {
1320 	__be16 tmp = value;
1321 
1322 	return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1323 }
1324 
1325 /**
1326  * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1327  * @skb: socket buffer to add attribute to
1328  * @attrtype: attribute type
1329  * @value: numeric value
1330  */
nla_put_net16(struct sk_buff * skb,int attrtype,__be16 value)1331 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1332 {
1333 	__be16 tmp = value;
1334 
1335 	return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1336 }
1337 
1338 /**
1339  * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1340  * @skb: socket buffer to add attribute to
1341  * @attrtype: attribute type
1342  * @value: numeric value
1343  */
nla_put_le16(struct sk_buff * skb,int attrtype,__le16 value)1344 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1345 {
1346 	__le16 tmp = value;
1347 
1348 	return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1349 }
1350 
1351 /**
1352  * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1353  * @skb: socket buffer to add attribute to
1354  * @attrtype: attribute type
1355  * @value: numeric value
1356  */
nla_put_u32(struct sk_buff * skb,int attrtype,u32 value)1357 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1358 {
1359 	u32 tmp = value;
1360 
1361 	return nla_put(skb, attrtype, sizeof(u32), &tmp);
1362 }
1363 
1364 /**
1365  * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1366  * @skb: socket buffer to add attribute to
1367  * @attrtype: attribute type
1368  * @value: numeric value
1369  */
nla_put_be32(struct sk_buff * skb,int attrtype,__be32 value)1370 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1371 {
1372 	__be32 tmp = value;
1373 
1374 	return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1375 }
1376 
1377 /**
1378  * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1379  * @skb: socket buffer to add attribute to
1380  * @attrtype: attribute type
1381  * @value: numeric value
1382  */
nla_put_net32(struct sk_buff * skb,int attrtype,__be32 value)1383 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1384 {
1385 	__be32 tmp = value;
1386 
1387 	return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1388 }
1389 
1390 /**
1391  * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1392  * @skb: socket buffer to add attribute to
1393  * @attrtype: attribute type
1394  * @value: numeric value
1395  */
nla_put_le32(struct sk_buff * skb,int attrtype,__le32 value)1396 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1397 {
1398 	__le32 tmp = value;
1399 
1400 	return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1401 }
1402 
1403 /**
1404  * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1405  * @skb: socket buffer to add attribute to
1406  * @attrtype: attribute type
1407  * @value: numeric value
1408  * @padattr: attribute type for the padding
1409  */
nla_put_u64_64bit(struct sk_buff * skb,int attrtype,u64 value,int padattr)1410 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1411 				    u64 value, int padattr)
1412 {
1413 	u64 tmp = value;
1414 
1415 	return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1416 }
1417 
1418 /**
1419  * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1420  * @skb: socket buffer to add attribute to
1421  * @attrtype: attribute type
1422  * @value: numeric value
1423  * @padattr: attribute type for the padding
1424  */
nla_put_be64(struct sk_buff * skb,int attrtype,__be64 value,int padattr)1425 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1426 			       int padattr)
1427 {
1428 	__be64 tmp = value;
1429 
1430 	return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1431 }
1432 
1433 /**
1434  * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1435  * @skb: socket buffer to add attribute to
1436  * @attrtype: attribute type
1437  * @value: numeric value
1438  * @padattr: attribute type for the padding
1439  */
nla_put_net64(struct sk_buff * skb,int attrtype,__be64 value,int padattr)1440 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1441 				int padattr)
1442 {
1443 	__be64 tmp = value;
1444 
1445 	return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1446 			    padattr);
1447 }
1448 
1449 /**
1450  * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1451  * @skb: socket buffer to add attribute to
1452  * @attrtype: attribute type
1453  * @value: numeric value
1454  * @padattr: attribute type for the padding
1455  */
nla_put_le64(struct sk_buff * skb,int attrtype,__le64 value,int padattr)1456 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1457 			       int padattr)
1458 {
1459 	__le64 tmp = value;
1460 
1461 	return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1462 }
1463 
1464 /**
1465  * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1466  * @skb: socket buffer to add attribute to
1467  * @attrtype: attribute type
1468  * @value: numeric value
1469  */
nla_put_s8(struct sk_buff * skb,int attrtype,s8 value)1470 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1471 {
1472 	s8 tmp = value;
1473 
1474 	return nla_put(skb, attrtype, sizeof(s8), &tmp);
1475 }
1476 
1477 /**
1478  * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1479  * @skb: socket buffer to add attribute to
1480  * @attrtype: attribute type
1481  * @value: numeric value
1482  */
nla_put_s16(struct sk_buff * skb,int attrtype,s16 value)1483 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1484 {
1485 	s16 tmp = value;
1486 
1487 	return nla_put(skb, attrtype, sizeof(s16), &tmp);
1488 }
1489 
1490 /**
1491  * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1492  * @skb: socket buffer to add attribute to
1493  * @attrtype: attribute type
1494  * @value: numeric value
1495  */
nla_put_s32(struct sk_buff * skb,int attrtype,s32 value)1496 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1497 {
1498 	s32 tmp = value;
1499 
1500 	return nla_put(skb, attrtype, sizeof(s32), &tmp);
1501 }
1502 
1503 /**
1504  * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1505  * @skb: socket buffer to add attribute to
1506  * @attrtype: attribute type
1507  * @value: numeric value
1508  * @padattr: attribute type for the padding
1509  */
nla_put_s64(struct sk_buff * skb,int attrtype,s64 value,int padattr)1510 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1511 			      int padattr)
1512 {
1513 	s64 tmp = value;
1514 
1515 	return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1516 }
1517 
1518 /**
1519  * nla_put_string - Add a string netlink attribute to a socket buffer
1520  * @skb: socket buffer to add attribute to
1521  * @attrtype: attribute type
1522  * @str: NUL terminated string
1523  */
nla_put_string(struct sk_buff * skb,int attrtype,const char * str)1524 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1525 				 const char *str)
1526 {
1527 	return nla_put(skb, attrtype, strlen(str) + 1, str);
1528 }
1529 
1530 /**
1531  * nla_put_flag - Add a flag netlink attribute to a socket buffer
1532  * @skb: socket buffer to add attribute to
1533  * @attrtype: attribute type
1534  */
nla_put_flag(struct sk_buff * skb,int attrtype)1535 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1536 {
1537 	return nla_put(skb, attrtype, 0, NULL);
1538 }
1539 
1540 /**
1541  * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1542  * @skb: socket buffer to add attribute to
1543  * @attrtype: attribute type
1544  * @njiffies: number of jiffies to convert to msecs
1545  * @padattr: attribute type for the padding
1546  */
nla_put_msecs(struct sk_buff * skb,int attrtype,unsigned long njiffies,int padattr)1547 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1548 				unsigned long njiffies, int padattr)
1549 {
1550 	u64 tmp = jiffies_to_msecs(njiffies);
1551 
1552 	return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1553 }
1554 
1555 /**
1556  * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1557  * buffer
1558  * @skb: socket buffer to add attribute to
1559  * @attrtype: attribute type
1560  * @addr: IPv4 address
1561  */
nla_put_in_addr(struct sk_buff * skb,int attrtype,__be32 addr)1562 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1563 				  __be32 addr)
1564 {
1565 	__be32 tmp = addr;
1566 
1567 	return nla_put_be32(skb, attrtype, tmp);
1568 }
1569 
1570 /**
1571  * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1572  * buffer
1573  * @skb: socket buffer to add attribute to
1574  * @attrtype: attribute type
1575  * @addr: IPv6 address
1576  */
nla_put_in6_addr(struct sk_buff * skb,int attrtype,const struct in6_addr * addr)1577 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1578 				   const struct in6_addr *addr)
1579 {
1580 	return nla_put(skb, attrtype, sizeof(*addr), addr);
1581 }
1582 
1583 /**
1584  * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1585  * @skb: socket buffer to add attribute to
1586  * @attrtype: attribute type
1587  * @value: value carrying bits
1588  * @selector: selector of valid bits
1589  */
nla_put_bitfield32(struct sk_buff * skb,int attrtype,__u32 value,__u32 selector)1590 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1591 				     __u32 value, __u32 selector)
1592 {
1593 	struct nla_bitfield32 tmp = { value, selector, };
1594 
1595 	return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1596 }
1597 
1598 /**
1599  * nla_get_u32 - return payload of u32 attribute
1600  * @nla: u32 netlink attribute
1601  */
nla_get_u32(const struct nlattr * nla)1602 static inline u32 nla_get_u32(const struct nlattr *nla)
1603 {
1604 	return *(u32 *) nla_data(nla);
1605 }
1606 
1607 /**
1608  * nla_get_be32 - return payload of __be32 attribute
1609  * @nla: __be32 netlink attribute
1610  */
nla_get_be32(const struct nlattr * nla)1611 static inline __be32 nla_get_be32(const struct nlattr *nla)
1612 {
1613 	return *(__be32 *) nla_data(nla);
1614 }
1615 
1616 /**
1617  * nla_get_le32 - return payload of __le32 attribute
1618  * @nla: __le32 netlink attribute
1619  */
nla_get_le32(const struct nlattr * nla)1620 static inline __le32 nla_get_le32(const struct nlattr *nla)
1621 {
1622 	return *(__le32 *) nla_data(nla);
1623 }
1624 
1625 /**
1626  * nla_get_u16 - return payload of u16 attribute
1627  * @nla: u16 netlink attribute
1628  */
nla_get_u16(const struct nlattr * nla)1629 static inline u16 nla_get_u16(const struct nlattr *nla)
1630 {
1631 	return *(u16 *) nla_data(nla);
1632 }
1633 
1634 /**
1635  * nla_get_be16 - return payload of __be16 attribute
1636  * @nla: __be16 netlink attribute
1637  */
nla_get_be16(const struct nlattr * nla)1638 static inline __be16 nla_get_be16(const struct nlattr *nla)
1639 {
1640 	return *(__be16 *) nla_data(nla);
1641 }
1642 
1643 /**
1644  * nla_get_le16 - return payload of __le16 attribute
1645  * @nla: __le16 netlink attribute
1646  */
nla_get_le16(const struct nlattr * nla)1647 static inline __le16 nla_get_le16(const struct nlattr *nla)
1648 {
1649 	return *(__le16 *) nla_data(nla);
1650 }
1651 
1652 /**
1653  * nla_get_u8 - return payload of u8 attribute
1654  * @nla: u8 netlink attribute
1655  */
nla_get_u8(const struct nlattr * nla)1656 static inline u8 nla_get_u8(const struct nlattr *nla)
1657 {
1658 	return *(u8 *) nla_data(nla);
1659 }
1660 
1661 /**
1662  * nla_get_u64 - return payload of u64 attribute
1663  * @nla: u64 netlink attribute
1664  */
nla_get_u64(const struct nlattr * nla)1665 static inline u64 nla_get_u64(const struct nlattr *nla)
1666 {
1667 	u64 tmp;
1668 
1669 	nla_memcpy(&tmp, nla, sizeof(tmp));
1670 
1671 	return tmp;
1672 }
1673 
1674 /**
1675  * nla_get_be64 - return payload of __be64 attribute
1676  * @nla: __be64 netlink attribute
1677  */
nla_get_be64(const struct nlattr * nla)1678 static inline __be64 nla_get_be64(const struct nlattr *nla)
1679 {
1680 	__be64 tmp;
1681 
1682 	nla_memcpy(&tmp, nla, sizeof(tmp));
1683 
1684 	return tmp;
1685 }
1686 
1687 /**
1688  * nla_get_le64 - return payload of __le64 attribute
1689  * @nla: __le64 netlink attribute
1690  */
nla_get_le64(const struct nlattr * nla)1691 static inline __le64 nla_get_le64(const struct nlattr *nla)
1692 {
1693 	return *(__le64 *) nla_data(nla);
1694 }
1695 
1696 /**
1697  * nla_get_s32 - return payload of s32 attribute
1698  * @nla: s32 netlink attribute
1699  */
nla_get_s32(const struct nlattr * nla)1700 static inline s32 nla_get_s32(const struct nlattr *nla)
1701 {
1702 	return *(s32 *) nla_data(nla);
1703 }
1704 
1705 /**
1706  * nla_get_s16 - return payload of s16 attribute
1707  * @nla: s16 netlink attribute
1708  */
nla_get_s16(const struct nlattr * nla)1709 static inline s16 nla_get_s16(const struct nlattr *nla)
1710 {
1711 	return *(s16 *) nla_data(nla);
1712 }
1713 
1714 /**
1715  * nla_get_s8 - return payload of s8 attribute
1716  * @nla: s8 netlink attribute
1717  */
nla_get_s8(const struct nlattr * nla)1718 static inline s8 nla_get_s8(const struct nlattr *nla)
1719 {
1720 	return *(s8 *) nla_data(nla);
1721 }
1722 
1723 /**
1724  * nla_get_s64 - return payload of s64 attribute
1725  * @nla: s64 netlink attribute
1726  */
nla_get_s64(const struct nlattr * nla)1727 static inline s64 nla_get_s64(const struct nlattr *nla)
1728 {
1729 	s64 tmp;
1730 
1731 	nla_memcpy(&tmp, nla, sizeof(tmp));
1732 
1733 	return tmp;
1734 }
1735 
1736 /**
1737  * nla_get_flag - return payload of flag attribute
1738  * @nla: flag netlink attribute
1739  */
nla_get_flag(const struct nlattr * nla)1740 static inline int nla_get_flag(const struct nlattr *nla)
1741 {
1742 	return !!nla;
1743 }
1744 
1745 /**
1746  * nla_get_msecs - return payload of msecs attribute
1747  * @nla: msecs netlink attribute
1748  *
1749  * Returns the number of milliseconds in jiffies.
1750  */
nla_get_msecs(const struct nlattr * nla)1751 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1752 {
1753 	u64 msecs = nla_get_u64(nla);
1754 
1755 	return msecs_to_jiffies((unsigned long) msecs);
1756 }
1757 
1758 /**
1759  * nla_get_in_addr - return payload of IPv4 address attribute
1760  * @nla: IPv4 address netlink attribute
1761  */
nla_get_in_addr(const struct nlattr * nla)1762 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1763 {
1764 	return *(__be32 *) nla_data(nla);
1765 }
1766 
1767 /**
1768  * nla_get_in6_addr - return payload of IPv6 address attribute
1769  * @nla: IPv6 address netlink attribute
1770  */
nla_get_in6_addr(const struct nlattr * nla)1771 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1772 {
1773 	struct in6_addr tmp;
1774 
1775 	nla_memcpy(&tmp, nla, sizeof(tmp));
1776 	return tmp;
1777 }
1778 
1779 /**
1780  * nla_get_bitfield32 - return payload of 32 bitfield attribute
1781  * @nla: nla_bitfield32 attribute
1782  */
nla_get_bitfield32(const struct nlattr * nla)1783 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1784 {
1785 	struct nla_bitfield32 tmp;
1786 
1787 	nla_memcpy(&tmp, nla, sizeof(tmp));
1788 	return tmp;
1789 }
1790 
1791 /**
1792  * nla_memdup - duplicate attribute memory (kmemdup)
1793  * @src: netlink attribute to duplicate from
1794  * @gfp: GFP mask
1795  */
nla_memdup(const struct nlattr * src,gfp_t gfp)1796 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1797 {
1798 	return kmemdup(nla_data(src), nla_len(src), gfp);
1799 }
1800 
1801 /**
1802  * nla_nest_start_noflag - Start a new level of nested attributes
1803  * @skb: socket buffer to add attributes to
1804  * @attrtype: attribute type of container
1805  *
1806  * This function exists for backward compatibility to use in APIs which never
1807  * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1808  * nla_nest_start() which sets the flag.
1809  *
1810  * Returns the container attribute or NULL on error
1811  */
nla_nest_start_noflag(struct sk_buff * skb,int attrtype)1812 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1813 						   int attrtype)
1814 {
1815 	struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1816 
1817 	if (nla_put(skb, attrtype, 0, NULL) < 0)
1818 		return NULL;
1819 
1820 	return start;
1821 }
1822 
1823 /**
1824  * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1825  * @skb: socket buffer to add attributes to
1826  * @attrtype: attribute type of container
1827  *
1828  * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1829  * flag. This is the preferred function to use in new code.
1830  *
1831  * Returns the container attribute or NULL on error
1832  */
nla_nest_start(struct sk_buff * skb,int attrtype)1833 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1834 {
1835 	return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1836 }
1837 
1838 /**
1839  * nla_nest_end - Finalize nesting of attributes
1840  * @skb: socket buffer the attributes are stored in
1841  * @start: container attribute
1842  *
1843  * Corrects the container attribute header to include the all
1844  * appeneded attributes.
1845  *
1846  * Returns the total data length of the skb.
1847  */
nla_nest_end(struct sk_buff * skb,struct nlattr * start)1848 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1849 {
1850 	start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1851 	return skb->len;
1852 }
1853 
1854 /**
1855  * nla_nest_cancel - Cancel nesting of attributes
1856  * @skb: socket buffer the message is stored in
1857  * @start: container attribute
1858  *
1859  * Removes the container attribute and including all nested
1860  * attributes. Returns -EMSGSIZE
1861  */
nla_nest_cancel(struct sk_buff * skb,struct nlattr * start)1862 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1863 {
1864 	nlmsg_trim(skb, start);
1865 }
1866 
1867 /**
1868  * __nla_validate_nested - Validate a stream of nested attributes
1869  * @start: container attribute
1870  * @maxtype: maximum attribute type to be expected
1871  * @policy: validation policy
1872  * @validate: validation strictness
1873  * @extack: extended ACK report struct
1874  *
1875  * Validates all attributes in the nested attribute stream against the
1876  * specified policy. Attributes with a type exceeding maxtype will be
1877  * ignored. See documenation of struct nla_policy for more details.
1878  *
1879  * Returns 0 on success or a negative error code.
1880  */
__nla_validate_nested(const struct nlattr * start,int maxtype,const struct nla_policy * policy,unsigned int validate,struct netlink_ext_ack * extack)1881 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1882 					const struct nla_policy *policy,
1883 					unsigned int validate,
1884 					struct netlink_ext_ack *extack)
1885 {
1886 	return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1887 			      validate, extack);
1888 }
1889 
1890 static inline int
nla_validate_nested(const struct nlattr * start,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)1891 nla_validate_nested(const struct nlattr *start, int maxtype,
1892 		    const struct nla_policy *policy,
1893 		    struct netlink_ext_ack *extack)
1894 {
1895 	return __nla_validate_nested(start, maxtype, policy,
1896 				     NL_VALIDATE_STRICT, extack);
1897 }
1898 
1899 static inline int
nla_validate_nested_deprecated(const struct nlattr * start,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)1900 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1901 			       const struct nla_policy *policy,
1902 			       struct netlink_ext_ack *extack)
1903 {
1904 	return __nla_validate_nested(start, maxtype, policy,
1905 				     NL_VALIDATE_LIBERAL, extack);
1906 }
1907 
1908 /**
1909  * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1910  * @skb: socket buffer the message is stored in
1911  *
1912  * Return true if padding is needed to align the next attribute (nla_data()) to
1913  * a 64-bit aligned area.
1914  */
nla_need_padding_for_64bit(struct sk_buff * skb)1915 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1916 {
1917 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1918 	/* The nlattr header is 4 bytes in size, that's why we test
1919 	 * if the skb->data _is_ aligned.  A NOP attribute, plus
1920 	 * nlattr header for next attribute, will make nla_data()
1921 	 * 8-byte aligned.
1922 	 */
1923 	if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1924 		return true;
1925 #endif
1926 	return false;
1927 }
1928 
1929 /**
1930  * nla_align_64bit - 64-bit align the nla_data() of next attribute
1931  * @skb: socket buffer the message is stored in
1932  * @padattr: attribute type for the padding
1933  *
1934  * Conditionally emit a padding netlink attribute in order to make
1935  * the next attribute we emit have a 64-bit aligned nla_data() area.
1936  * This will only be done in architectures which do not have
1937  * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1938  *
1939  * Returns zero on success or a negative error code.
1940  */
nla_align_64bit(struct sk_buff * skb,int padattr)1941 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1942 {
1943 	if (nla_need_padding_for_64bit(skb) &&
1944 	    !nla_reserve(skb, padattr, 0))
1945 		return -EMSGSIZE;
1946 
1947 	return 0;
1948 }
1949 
1950 /**
1951  * nla_total_size_64bit - total length of attribute including padding
1952  * @payload: length of payload
1953  */
nla_total_size_64bit(int payload)1954 static inline int nla_total_size_64bit(int payload)
1955 {
1956 	return NLA_ALIGN(nla_attr_size(payload))
1957 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1958 		+ NLA_ALIGN(nla_attr_size(0))
1959 #endif
1960 		;
1961 }
1962 
1963 /**
1964  * nla_for_each_attr - iterate over a stream of attributes
1965  * @pos: loop counter, set to current attribute
1966  * @head: head of attribute stream
1967  * @len: length of attribute stream
1968  * @rem: initialized to len, holds bytes currently remaining in stream
1969  */
1970 #define nla_for_each_attr(pos, head, len, rem) \
1971 	for (pos = head, rem = len; \
1972 	     nla_ok(pos, rem); \
1973 	     pos = nla_next(pos, &(rem)))
1974 
1975 /**
1976  * nla_for_each_nested - iterate over nested attributes
1977  * @pos: loop counter, set to current attribute
1978  * @nla: attribute containing the nested attributes
1979  * @rem: initialized to len, holds bytes currently remaining in stream
1980  */
1981 #define nla_for_each_nested(pos, nla, rem) \
1982 	nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1983 
1984 /**
1985  * nla_is_last - Test if attribute is last in stream
1986  * @nla: attribute to test
1987  * @rem: bytes remaining in stream
1988  */
nla_is_last(const struct nlattr * nla,int rem)1989 static inline bool nla_is_last(const struct nlattr *nla, int rem)
1990 {
1991 	return nla->nla_len == rem;
1992 }
1993 
1994 void nla_get_range_unsigned(const struct nla_policy *pt,
1995 			    struct netlink_range_validation *range);
1996 void nla_get_range_signed(const struct nla_policy *pt,
1997 			  struct netlink_range_validation_signed *range);
1998 
1999 struct netlink_policy_dump_state;
2000 
2001 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
2002 				   const struct nla_policy *policy,
2003 				   unsigned int maxtype);
2004 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
2005 				       const struct nla_policy *policy,
2006 				       unsigned int maxtype);
2007 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
2008 int netlink_policy_dump_write(struct sk_buff *skb,
2009 			      struct netlink_policy_dump_state *state);
2010 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
2011 int netlink_policy_dump_write_attr(struct sk_buff *skb,
2012 				   const struct nla_policy *pt,
2013 				   int nestattr);
2014 void netlink_policy_dump_free(struct netlink_policy_dump_state *state);
2015 
2016 #endif
2017