xref: /linux/include/net/netlink.h (revision 9410645520e9b820069761f3450ef6661418e279)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __NET_NETLINK_H
3 #define __NET_NETLINK_H
4 
5 #include <linux/types.h>
6 #include <linux/netlink.h>
7 #include <linux/jiffies.h>
8 #include <linux/in6.h>
9 
10 /* ========================================================================
11  *         Netlink Messages and Attributes Interface (As Seen On TV)
12  * ------------------------------------------------------------------------
13  *                          Messages Interface
14  * ------------------------------------------------------------------------
15  *
16  * Message Format:
17  *    <--- nlmsg_total_size(payload)  --->
18  *    <-- nlmsg_msg_size(payload) ->
19  *   +----------+- - -+-------------+- - -+-------- - -
20  *   | nlmsghdr | Pad |   Payload   | Pad | nlmsghdr
21  *   +----------+- - -+-------------+- - -+-------- - -
22  *   nlmsg_data(nlh)---^                   ^
23  *   nlmsg_next(nlh)-----------------------+
24  *
25  * Payload Format:
26  *    <---------------------- nlmsg_len(nlh) --------------------->
27  *    <------ hdrlen ------>       <- nlmsg_attrlen(nlh, hdrlen) ->
28  *   +----------------------+- - -+--------------------------------+
29  *   |     Family Header    | Pad |           Attributes           |
30  *   +----------------------+- - -+--------------------------------+
31  *   nlmsg_attrdata(nlh, hdrlen)---^
32  *
33  * Data Structures:
34  *   struct nlmsghdr			netlink message header
35  *
36  * Message Construction:
37  *   nlmsg_new()			create a new netlink message
38  *   nlmsg_put()			add a netlink message to an skb
39  *   nlmsg_put_answer()			callback based nlmsg_put()
40  *   nlmsg_end()			finalize netlink message
41  *   nlmsg_get_pos()			return current position in message
42  *   nlmsg_trim()			trim part of message
43  *   nlmsg_cancel()			cancel message construction
44  *   nlmsg_consume()			free a netlink message (expected)
45  *   nlmsg_free()			free a netlink message (drop)
46  *
47  * Message Sending:
48  *   nlmsg_multicast()			multicast message to several groups
49  *   nlmsg_unicast()			unicast a message to a single socket
50  *   nlmsg_notify()			send notification message
51  *
52  * Message Length Calculations:
53  *   nlmsg_msg_size(payload)		length of message w/o padding
54  *   nlmsg_total_size(payload)		length of message w/ padding
55  *   nlmsg_padlen(payload)		length of padding at tail
56  *
57  * Message Payload Access:
58  *   nlmsg_data(nlh)			head of message payload
59  *   nlmsg_len(nlh)			length of message payload
60  *   nlmsg_attrdata(nlh, hdrlen)	head of attributes data
61  *   nlmsg_attrlen(nlh, hdrlen)		length of attributes data
62  *
63  * Message Parsing:
64  *   nlmsg_ok(nlh, remaining)		does nlh fit into remaining bytes?
65  *   nlmsg_next(nlh, remaining)		get next netlink message
66  *   nlmsg_parse()			parse attributes of a message
67  *   nlmsg_find_attr()			find an attribute in a message
68  *   nlmsg_for_each_msg()		loop over all messages
69  *   nlmsg_validate()			validate netlink message incl. attrs
70  *   nlmsg_for_each_attr()		loop over all attributes
71  *
72  * Misc:
73  *   nlmsg_report()			report back to application?
74  *
75  * ------------------------------------------------------------------------
76  *                          Attributes Interface
77  * ------------------------------------------------------------------------
78  *
79  * Attribute Format:
80  *    <------- nla_total_size(payload) ------->
81  *    <---- nla_attr_size(payload) ----->
82  *   +----------+- - -+- - - - - - - - - +- - -+-------- - -
83  *   |  Header  | Pad |     Payload      | Pad |  Header
84  *   +----------+- - -+- - - - - - - - - +- - -+-------- - -
85  *                     <- nla_len(nla) ->      ^
86  *   nla_data(nla)----^                        |
87  *   nla_next(nla)-----------------------------'
88  *
89  * Data Structures:
90  *   struct nlattr			netlink attribute header
91  *
92  * Attribute Construction:
93  *   nla_reserve(skb, type, len)	reserve room for an attribute
94  *   nla_reserve_nohdr(skb, len)	reserve room for an attribute w/o hdr
95  *   nla_put(skb, type, len, data)	add attribute to skb
96  *   nla_put_nohdr(skb, len, data)	add attribute w/o hdr
97  *   nla_append(skb, len, data)		append data to skb
98  *
99  * Attribute Construction for Basic Types:
100  *   nla_put_u8(skb, type, value)	add u8 attribute to skb
101  *   nla_put_u16(skb, type, value)	add u16 attribute to skb
102  *   nla_put_u32(skb, type, value)	add u32 attribute to skb
103  *   nla_put_u64_64bit(skb, type,
104  *                     value, padattr)	add u64 attribute to skb
105  *   nla_put_s8(skb, type, value)	add s8 attribute to skb
106  *   nla_put_s16(skb, type, value)	add s16 attribute to skb
107  *   nla_put_s32(skb, type, value)	add s32 attribute to skb
108  *   nla_put_s64(skb, type, value,
109  *               padattr)		add s64 attribute to skb
110  *   nla_put_string(skb, type, str)	add string attribute to skb
111  *   nla_put_flag(skb, type)		add flag attribute to skb
112  *   nla_put_msecs(skb, type, jiffies,
113  *                 padattr)		add msecs attribute to skb
114  *   nla_put_in_addr(skb, type, addr)	add IPv4 address attribute to skb
115  *   nla_put_in6_addr(skb, type, addr)	add IPv6 address attribute to skb
116  *
117  * Nested Attributes Construction:
118  *   nla_nest_start(skb, type)		start a nested attribute
119  *   nla_nest_end(skb, nla)		finalize a nested attribute
120  *   nla_nest_cancel(skb, nla)		cancel nested attribute construction
121  *
122  * Attribute Length Calculations:
123  *   nla_attr_size(payload)		length of attribute w/o padding
124  *   nla_total_size(payload)		length of attribute w/ padding
125  *   nla_padlen(payload)		length of padding
126  *
127  * Attribute Payload Access:
128  *   nla_data(nla)			head of attribute payload
129  *   nla_len(nla)			length of attribute payload
130  *
131  * Attribute Payload Access for Basic Types:
132  *   nla_get_uint(nla)			get payload for a uint attribute
133  *   nla_get_sint(nla)			get payload for a sint attribute
134  *   nla_get_u8(nla)			get payload for a u8 attribute
135  *   nla_get_u16(nla)			get payload for a u16 attribute
136  *   nla_get_u32(nla)			get payload for a u32 attribute
137  *   nla_get_u64(nla)			get payload for a u64 attribute
138  *   nla_get_s8(nla)			get payload for a s8 attribute
139  *   nla_get_s16(nla)			get payload for a s16 attribute
140  *   nla_get_s32(nla)			get payload for a s32 attribute
141  *   nla_get_s64(nla)			get payload for a s64 attribute
142  *   nla_get_flag(nla)			return 1 if flag is true
143  *   nla_get_msecs(nla)			get payload for a msecs attribute
144  *
145  * Attribute Misc:
146  *   nla_memcpy(dest, nla, count)	copy attribute into memory
147  *   nla_memcmp(nla, data, size)	compare attribute with memory area
148  *   nla_strscpy(dst, nla, size)	copy attribute to a sized string
149  *   nla_strcmp(nla, str)		compare attribute with string
150  *
151  * Attribute Parsing:
152  *   nla_ok(nla, remaining)		does nla fit into remaining bytes?
153  *   nla_next(nla, remaining)		get next netlink attribute
154  *   nla_validate()			validate a stream of attributes
155  *   nla_validate_nested()		validate a stream of nested attributes
156  *   nla_find()				find attribute in stream of attributes
157  *   nla_find_nested()			find attribute in nested attributes
158  *   nla_parse()			parse and validate stream of attrs
159  *   nla_parse_nested()			parse nested attributes
160  *   nla_for_each_attr()		loop over all attributes
161  *   nla_for_each_attr_type()		loop over all attributes with the
162  *					given type
163  *   nla_for_each_nested()		loop over the nested attributes
164  *   nla_for_each_nested_type()		loop over the nested attributes with
165  *					the given type
166  *=========================================================================
167  */
168 
169  /**
170   * Standard attribute types to specify validation policy
171   */
172 enum {
173 	NLA_UNSPEC,
174 	NLA_U8,
175 	NLA_U16,
176 	NLA_U32,
177 	NLA_U64,
178 	NLA_STRING,
179 	NLA_FLAG,
180 	NLA_MSECS,
181 	NLA_NESTED,
182 	NLA_NESTED_ARRAY,
183 	NLA_NUL_STRING,
184 	NLA_BINARY,
185 	NLA_S8,
186 	NLA_S16,
187 	NLA_S32,
188 	NLA_S64,
189 	NLA_BITFIELD32,
190 	NLA_REJECT,
191 	NLA_BE16,
192 	NLA_BE32,
193 	NLA_SINT,
194 	NLA_UINT,
195 	__NLA_TYPE_MAX,
196 };
197 
198 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
199 
200 struct netlink_range_validation {
201 	u64 min, max;
202 };
203 
204 struct netlink_range_validation_signed {
205 	s64 min, max;
206 };
207 
208 enum nla_policy_validation {
209 	NLA_VALIDATE_NONE,
210 	NLA_VALIDATE_RANGE,
211 	NLA_VALIDATE_RANGE_WARN_TOO_LONG,
212 	NLA_VALIDATE_MIN,
213 	NLA_VALIDATE_MAX,
214 	NLA_VALIDATE_MASK,
215 	NLA_VALIDATE_RANGE_PTR,
216 	NLA_VALIDATE_FUNCTION,
217 };
218 
219 /**
220  * struct nla_policy - attribute validation policy
221  * @type: Type of attribute or NLA_UNSPEC
222  * @validation_type: type of attribute validation done in addition to
223  *	type-specific validation (e.g. range, function call), see
224  *	&enum nla_policy_validation
225  * @len: Type specific length of payload
226  *
227  * Policies are defined as arrays of this struct, the array must be
228  * accessible by attribute type up to the highest identifier to be expected.
229  *
230  * Meaning of `len' field:
231  *    NLA_STRING           Maximum length of string
232  *    NLA_NUL_STRING       Maximum length of string (excluding NUL)
233  *    NLA_FLAG             Unused
234  *    NLA_BINARY           Maximum length of attribute payload
235  *                         (but see also below with the validation type)
236  *    NLA_NESTED,
237  *    NLA_NESTED_ARRAY     Length verification is done by checking len of
238  *                         nested header (or empty); len field is used if
239  *                         nested_policy is also used, for the max attr
240  *                         number in the nested policy.
241  *    NLA_SINT, NLA_UINT,
242  *    NLA_U8, NLA_U16,
243  *    NLA_U32, NLA_U64,
244  *    NLA_S8, NLA_S16,
245  *    NLA_S32, NLA_S64,
246  *    NLA_BE16, NLA_BE32,
247  *    NLA_MSECS            Leaving the length field zero will verify the
248  *                         given type fits, using it verifies minimum length
249  *                         just like "All other"
250  *    NLA_BITFIELD32       Unused
251  *    NLA_REJECT           Unused
252  *    All other            Minimum length of attribute payload
253  *
254  * Meaning of validation union:
255  *    NLA_BITFIELD32       This is a 32-bit bitmap/bitselector attribute and
256  *                         `bitfield32_valid' is the u32 value of valid flags
257  *    NLA_REJECT           This attribute is always rejected and `reject_message'
258  *                         may point to a string to report as the error instead
259  *                         of the generic one in extended ACK.
260  *    NLA_NESTED           `nested_policy' to a nested policy to validate, must
261  *                         also set `len' to the max attribute number. Use the
262  *                         provided NLA_POLICY_NESTED() macro.
263  *                         Note that nla_parse() will validate, but of course not
264  *                         parse, the nested sub-policies.
265  *    NLA_NESTED_ARRAY     `nested_policy' points to a nested policy to validate,
266  *                         must also set `len' to the max attribute number. Use
267  *                         the provided NLA_POLICY_NESTED_ARRAY() macro.
268  *                         The difference to NLA_NESTED is the structure:
269  *                         NLA_NESTED has the nested attributes directly inside
270  *                         while an array has the nested attributes at another
271  *                         level down and the attribute types directly in the
272  *                         nesting don't matter.
273  *    NLA_UINT,
274  *    NLA_U8,
275  *    NLA_U16,
276  *    NLA_U32,
277  *    NLA_U64,
278  *    NLA_BE16,
279  *    NLA_BE32,
280  *    NLA_SINT,
281  *    NLA_S8,
282  *    NLA_S16,
283  *    NLA_S32,
284  *    NLA_S64              The `min' and `max' fields are used depending on the
285  *                         validation_type field, if that is min/max/range then
286  *                         the min, max or both are used (respectively) to check
287  *                         the value of the integer attribute.
288  *                         Note that in the interest of code simplicity and
289  *                         struct size both limits are s16, so you cannot
290  *                         enforce a range that doesn't fall within the range
291  *                         of s16 - do that using the NLA_POLICY_FULL_RANGE()
292  *                         or NLA_POLICY_FULL_RANGE_SIGNED() macros instead.
293  *                         Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
294  *                         NLA_POLICY_RANGE() macros.
295  *    NLA_UINT,
296  *    NLA_U8,
297  *    NLA_U16,
298  *    NLA_U32,
299  *    NLA_U64              If the validation_type field instead is set to
300  *                         NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
301  *                         to a struct netlink_range_validation that indicates
302  *                         the min/max values.
303  *                         Use NLA_POLICY_FULL_RANGE().
304  *    NLA_SINT,
305  *    NLA_S8,
306  *    NLA_S16,
307  *    NLA_S32,
308  *    NLA_S64              If the validation_type field instead is set to
309  *                         NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
310  *                         pointer to a struct netlink_range_validation_signed
311  *                         that indicates the min/max values.
312  *                         Use NLA_POLICY_FULL_RANGE_SIGNED().
313  *
314  *    NLA_BINARY           If the validation type is like the ones for integers
315  *                         above, then the min/max length (not value like for
316  *                         integers) of the attribute is enforced.
317  *
318  *    All other            Unused - but note that it's a union
319  *
320  * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
321  *    NLA_BINARY           Validation function called for the attribute.
322  *    All other            Unused - but note that it's a union
323  *
324  * Example:
325  *
326  * static const u32 myvalidflags = 0xff231023;
327  *
328  * static const struct nla_policy my_policy[ATTR_MAX+1] = {
329  * 	[ATTR_FOO] = { .type = NLA_U16 },
330  *	[ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
331  *	[ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)),
332  *	[ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
333  * };
334  */
335 struct nla_policy {
336 	u8		type;
337 	u8		validation_type;
338 	u16		len;
339 	union {
340 		/**
341 		 * @strict_start_type: first attribute to validate strictly
342 		 *
343 		 * This entry is special, and used for the attribute at index 0
344 		 * only, and specifies special data about the policy, namely it
345 		 * specifies the "boundary type" where strict length validation
346 		 * starts for any attribute types >= this value, also, strict
347 		 * nesting validation starts here.
348 		 *
349 		 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
350 		 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to
351 		 * get the previous pure { .len = xyz } behaviour. The advantage
352 		 * of this is that types not specified in the policy will be
353 		 * rejected.
354 		 *
355 		 * For completely new families it should be set to 1 so that the
356 		 * validation is enforced for all attributes. For existing ones
357 		 * it should be set at least when new attributes are added to
358 		 * the enum used by the policy, and be set to the new value that
359 		 * was added to enforce strict validation from thereon.
360 		 */
361 		u16 strict_start_type;
362 
363 		/* private: use NLA_POLICY_*() to set */
364 		const u32 bitfield32_valid;
365 		const u32 mask;
366 		const char *reject_message;
367 		const struct nla_policy *nested_policy;
368 		const struct netlink_range_validation *range;
369 		const struct netlink_range_validation_signed *range_signed;
370 		struct {
371 			s16 min, max;
372 		};
373 		int (*validate)(const struct nlattr *attr,
374 				struct netlink_ext_ack *extack);
375 	};
376 };
377 
378 #define NLA_POLICY_ETH_ADDR		NLA_POLICY_EXACT_LEN(ETH_ALEN)
379 #define NLA_POLICY_ETH_ADDR_COMPAT	NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
380 
381 #define _NLA_POLICY_NESTED(maxattr, policy) \
382 	{ .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
383 #define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
384 	{ .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
385 #define NLA_POLICY_NESTED(policy) \
386 	_NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
387 #define NLA_POLICY_NESTED_ARRAY(policy) \
388 	_NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
389 #define NLA_POLICY_BITFIELD32(valid) \
390 	{ .type = NLA_BITFIELD32, .bitfield32_valid = valid }
391 
392 #define __NLA_IS_UINT_TYPE(tp)					\
393 	(tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 ||	\
394 	 tp == NLA_U64 || tp == NLA_UINT ||			\
395 	 tp == NLA_BE16 || tp == NLA_BE32)
396 #define __NLA_IS_SINT_TYPE(tp)						\
397 	(tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64 || \
398 	 tp == NLA_SINT)
399 
400 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
401 #define NLA_ENSURE_UINT_TYPE(tp)			\
402 	(__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp)
403 #define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp)		\
404 	(__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) ||	\
405 		      tp == NLA_MSECS ||		\
406 		      tp == NLA_BINARY) + tp)
407 #define NLA_ENSURE_SINT_TYPE(tp)			\
408 	(__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp)
409 #define NLA_ENSURE_INT_OR_BINARY_TYPE(tp)		\
410 	(__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) ||		\
411 		      __NLA_IS_SINT_TYPE(tp) ||		\
412 		      tp == NLA_MSECS ||		\
413 		      tp == NLA_BINARY) + tp)
414 #define NLA_ENSURE_NO_VALIDATION_PTR(tp)		\
415 	(__NLA_ENSURE(tp != NLA_BITFIELD32 &&		\
416 		      tp != NLA_REJECT &&		\
417 		      tp != NLA_NESTED &&		\
418 		      tp != NLA_NESTED_ARRAY) + tp)
419 
420 #define NLA_POLICY_RANGE(tp, _min, _max) {		\
421 	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
422 	.validation_type = NLA_VALIDATE_RANGE,		\
423 	.min = _min,					\
424 	.max = _max					\
425 }
426 
427 #define NLA_POLICY_FULL_RANGE(tp, _range) {		\
428 	.type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp),	\
429 	.validation_type = NLA_VALIDATE_RANGE_PTR,	\
430 	.range = _range,				\
431 }
432 
433 #define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) {	\
434 	.type = NLA_ENSURE_SINT_TYPE(tp),		\
435 	.validation_type = NLA_VALIDATE_RANGE_PTR,	\
436 	.range_signed = _range,				\
437 }
438 
439 #define NLA_POLICY_MIN(tp, _min) {			\
440 	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
441 	.validation_type = NLA_VALIDATE_MIN,		\
442 	.min = _min,					\
443 }
444 
445 #define NLA_POLICY_MAX(tp, _max) {			\
446 	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
447 	.validation_type = NLA_VALIDATE_MAX,		\
448 	.max = _max,					\
449 }
450 
451 #define NLA_POLICY_MASK(tp, _mask) {			\
452 	.type = NLA_ENSURE_UINT_TYPE(tp),		\
453 	.validation_type = NLA_VALIDATE_MASK,		\
454 	.mask = _mask,					\
455 }
456 
457 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) {		\
458 	.type = NLA_ENSURE_NO_VALIDATION_PTR(tp),	\
459 	.validation_type = NLA_VALIDATE_FUNCTION,	\
460 	.validate = fn,					\
461 	.len = __VA_ARGS__ + 0,				\
462 }
463 
464 #define NLA_POLICY_EXACT_LEN(_len)	NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
465 #define NLA_POLICY_EXACT_LEN_WARN(_len) {			\
466 	.type = NLA_BINARY,					\
467 	.validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG,	\
468 	.min = _len,						\
469 	.max = _len						\
470 }
471 #define NLA_POLICY_MIN_LEN(_len)	NLA_POLICY_MIN(NLA_BINARY, _len)
472 
473 /**
474  * struct nl_info - netlink source information
475  * @nlh: Netlink message header of original request
476  * @nl_net: Network namespace
477  * @portid: Netlink PORTID of requesting application
478  * @skip_notify: Skip netlink notifications to user space
479  * @skip_notify_kernel: Skip selected in-kernel notifications
480  */
481 struct nl_info {
482 	struct nlmsghdr		*nlh;
483 	struct net		*nl_net;
484 	u32			portid;
485 	u8			skip_notify:1,
486 				skip_notify_kernel:1;
487 };
488 
489 /**
490  * enum netlink_validation - netlink message/attribute validation levels
491  * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
492  *	extra data at the end of the message, attributes being longer than
493  *	they should be, or unknown attributes being present.
494  * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
495  * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
496  *	this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
497  * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
498  *	This can safely be set by the kernel when the given policy has no
499  *	NLA_UNSPEC anymore, and can thus be used to ensure policy entries
500  *	are enforced going forward.
501  * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
502  *	U8, U16, U32 must have exact size, etc.)
503  * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
504  *	and unset for other policies.
505  */
506 enum netlink_validation {
507 	NL_VALIDATE_LIBERAL = 0,
508 	NL_VALIDATE_TRAILING = BIT(0),
509 	NL_VALIDATE_MAXTYPE = BIT(1),
510 	NL_VALIDATE_UNSPEC = BIT(2),
511 	NL_VALIDATE_STRICT_ATTRS = BIT(3),
512 	NL_VALIDATE_NESTED = BIT(4),
513 };
514 
515 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
516 				       NL_VALIDATE_MAXTYPE)
517 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
518 			    NL_VALIDATE_MAXTYPE |\
519 			    NL_VALIDATE_UNSPEC |\
520 			    NL_VALIDATE_STRICT_ATTRS |\
521 			    NL_VALIDATE_NESTED)
522 
523 int netlink_rcv_skb(struct sk_buff *skb,
524 		    int (*cb)(struct sk_buff *, struct nlmsghdr *,
525 			      struct netlink_ext_ack *));
526 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
527 		 unsigned int group, int report, gfp_t flags);
528 
529 int __nla_validate(const struct nlattr *head, int len, int maxtype,
530 		   const struct nla_policy *policy, unsigned int validate,
531 		   struct netlink_ext_ack *extack);
532 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
533 		int len, const struct nla_policy *policy, unsigned int validate,
534 		struct netlink_ext_ack *extack);
535 int nla_policy_len(const struct nla_policy *, int);
536 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
537 ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);
538 char *nla_strdup(const struct nlattr *nla, gfp_t flags);
539 int nla_memcpy(void *dest, const struct nlattr *src, int count);
540 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
541 int nla_strcmp(const struct nlattr *nla, const char *str);
542 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
543 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
544 				   int attrlen, int padattr);
545 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
546 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
547 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
548 				 int attrlen, int padattr);
549 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
550 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
551 	       const void *data);
552 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
553 		     const void *data, int padattr);
554 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
555 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
556 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
557 		  const void *data, int padattr);
558 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
559 int nla_append(struct sk_buff *skb, int attrlen, const void *data);
560 
561 /**************************************************************************
562  * Netlink Messages
563  **************************************************************************/
564 
565 /**
566  * nlmsg_msg_size - length of netlink message not including padding
567  * @payload: length of message payload
568  */
nlmsg_msg_size(int payload)569 static inline int nlmsg_msg_size(int payload)
570 {
571 	return NLMSG_HDRLEN + payload;
572 }
573 
574 /**
575  * nlmsg_total_size - length of netlink message including padding
576  * @payload: length of message payload
577  */
nlmsg_total_size(int payload)578 static inline int nlmsg_total_size(int payload)
579 {
580 	return NLMSG_ALIGN(nlmsg_msg_size(payload));
581 }
582 
583 /**
584  * nlmsg_padlen - length of padding at the message's tail
585  * @payload: length of message payload
586  */
nlmsg_padlen(int payload)587 static inline int nlmsg_padlen(int payload)
588 {
589 	return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
590 }
591 
592 /**
593  * nlmsg_data - head of message payload
594  * @nlh: netlink message header
595  */
nlmsg_data(const struct nlmsghdr * nlh)596 static inline void *nlmsg_data(const struct nlmsghdr *nlh)
597 {
598 	return (unsigned char *) nlh + NLMSG_HDRLEN;
599 }
600 
601 /**
602  * nlmsg_len - length of message payload
603  * @nlh: netlink message header
604  */
nlmsg_len(const struct nlmsghdr * nlh)605 static inline int nlmsg_len(const struct nlmsghdr *nlh)
606 {
607 	return nlh->nlmsg_len - NLMSG_HDRLEN;
608 }
609 
610 /**
611  * nlmsg_attrdata - head of attributes data
612  * @nlh: netlink message header
613  * @hdrlen: length of family specific header
614  */
nlmsg_attrdata(const struct nlmsghdr * nlh,int hdrlen)615 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
616 					    int hdrlen)
617 {
618 	unsigned char *data = nlmsg_data(nlh);
619 	return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
620 }
621 
622 /**
623  * nlmsg_attrlen - length of attributes data
624  * @nlh: netlink message header
625  * @hdrlen: length of family specific header
626  */
nlmsg_attrlen(const struct nlmsghdr * nlh,int hdrlen)627 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
628 {
629 	return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
630 }
631 
632 /**
633  * nlmsg_ok - check if the netlink message fits into the remaining bytes
634  * @nlh: netlink message header
635  * @remaining: number of bytes remaining in message stream
636  */
nlmsg_ok(const struct nlmsghdr * nlh,int remaining)637 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
638 {
639 	return (remaining >= (int) sizeof(struct nlmsghdr) &&
640 		nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
641 		nlh->nlmsg_len <= remaining);
642 }
643 
644 /**
645  * nlmsg_next - next netlink message in message stream
646  * @nlh: netlink message header
647  * @remaining: number of bytes remaining in message stream
648  *
649  * Returns the next netlink message in the message stream and
650  * decrements remaining by the size of the current message.
651  */
652 static inline struct nlmsghdr *
nlmsg_next(const struct nlmsghdr * nlh,int * remaining)653 nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
654 {
655 	int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
656 
657 	*remaining -= totlen;
658 
659 	return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
660 }
661 
662 /**
663  * nla_parse - Parse a stream of attributes into a tb buffer
664  * @tb: destination array with maxtype+1 elements
665  * @maxtype: maximum attribute type to be expected
666  * @head: head of attribute stream
667  * @len: length of attribute stream
668  * @policy: validation policy
669  * @extack: extended ACK pointer
670  *
671  * Parses a stream of attributes and stores a pointer to each attribute in
672  * the tb array accessible via the attribute type. Attributes with a type
673  * exceeding maxtype will be rejected, policy must be specified, attributes
674  * will be validated in the strictest way possible.
675  *
676  * Returns 0 on success or a negative error code.
677  */
nla_parse(struct nlattr ** tb,int maxtype,const struct nlattr * head,int len,const struct nla_policy * policy,struct netlink_ext_ack * extack)678 static inline int nla_parse(struct nlattr **tb, int maxtype,
679 			    const struct nlattr *head, int len,
680 			    const struct nla_policy *policy,
681 			    struct netlink_ext_ack *extack)
682 {
683 	return __nla_parse(tb, maxtype, head, len, policy,
684 			   NL_VALIDATE_STRICT, extack);
685 }
686 
687 /**
688  * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
689  * @tb: destination array with maxtype+1 elements
690  * @maxtype: maximum attribute type to be expected
691  * @head: head of attribute stream
692  * @len: length of attribute stream
693  * @policy: validation policy
694  * @extack: extended ACK pointer
695  *
696  * Parses a stream of attributes and stores a pointer to each attribute in
697  * the tb array accessible via the attribute type. Attributes with a type
698  * exceeding maxtype will be ignored and attributes from the policy are not
699  * always strictly validated (only for new attributes).
700  *
701  * Returns 0 on success or a negative error code.
702  */
nla_parse_deprecated(struct nlattr ** tb,int maxtype,const struct nlattr * head,int len,const struct nla_policy * policy,struct netlink_ext_ack * extack)703 static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
704 				       const struct nlattr *head, int len,
705 				       const struct nla_policy *policy,
706 				       struct netlink_ext_ack *extack)
707 {
708 	return __nla_parse(tb, maxtype, head, len, policy,
709 			   NL_VALIDATE_LIBERAL, extack);
710 }
711 
712 /**
713  * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
714  * @tb: destination array with maxtype+1 elements
715  * @maxtype: maximum attribute type to be expected
716  * @head: head of attribute stream
717  * @len: length of attribute stream
718  * @policy: validation policy
719  * @extack: extended ACK pointer
720  *
721  * Parses a stream of attributes and stores a pointer to each attribute in
722  * the tb array accessible via the attribute type. Attributes with a type
723  * exceeding maxtype will be rejected as well as trailing data, but the
724  * policy is not completely strictly validated (only for new attributes).
725  *
726  * Returns 0 on success or a negative error code.
727  */
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)728 static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
729 					      const struct nlattr *head,
730 					      int len,
731 					      const struct nla_policy *policy,
732 					      struct netlink_ext_ack *extack)
733 {
734 	return __nla_parse(tb, maxtype, head, len, policy,
735 			   NL_VALIDATE_DEPRECATED_STRICT, extack);
736 }
737 
738 /**
739  * __nlmsg_parse - parse attributes of a netlink message
740  * @nlh: netlink message header
741  * @hdrlen: length of family specific header
742  * @tb: destination array with maxtype+1 elements
743  * @maxtype: maximum attribute type to be expected
744  * @policy: validation policy
745  * @validate: validation strictness
746  * @extack: extended ACK report struct
747  *
748  * See nla_parse()
749  */
__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)750 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
751 				struct nlattr *tb[], int maxtype,
752 				const struct nla_policy *policy,
753 				unsigned int validate,
754 				struct netlink_ext_ack *extack)
755 {
756 	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
757 		NL_SET_ERR_MSG(extack, "Invalid header length");
758 		return -EINVAL;
759 	}
760 
761 	return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
762 			   nlmsg_attrlen(nlh, hdrlen), policy, validate,
763 			   extack);
764 }
765 
766 /**
767  * nlmsg_parse - parse attributes of a netlink message
768  * @nlh: netlink message header
769  * @hdrlen: length of family specific header
770  * @tb: destination array with maxtype+1 elements
771  * @maxtype: maximum attribute type to be expected
772  * @policy: validation policy
773  * @extack: extended ACK report struct
774  *
775  * See nla_parse()
776  */
nlmsg_parse(const struct nlmsghdr * nlh,int hdrlen,struct nlattr * tb[],int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)777 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
778 			      struct nlattr *tb[], int maxtype,
779 			      const struct nla_policy *policy,
780 			      struct netlink_ext_ack *extack)
781 {
782 	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
783 			     NL_VALIDATE_STRICT, extack);
784 }
785 
786 /**
787  * nlmsg_parse_deprecated - parse attributes of a netlink message
788  * @nlh: netlink message header
789  * @hdrlen: length of family specific header
790  * @tb: destination array with maxtype+1 elements
791  * @maxtype: maximum attribute type to be expected
792  * @policy: validation policy
793  * @extack: extended ACK report struct
794  *
795  * See nla_parse_deprecated()
796  */
nlmsg_parse_deprecated(const struct nlmsghdr * nlh,int hdrlen,struct nlattr * tb[],int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)797 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
798 					 struct nlattr *tb[], int maxtype,
799 					 const struct nla_policy *policy,
800 					 struct netlink_ext_ack *extack)
801 {
802 	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
803 			     NL_VALIDATE_LIBERAL, extack);
804 }
805 
806 /**
807  * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
808  * @nlh: netlink message header
809  * @hdrlen: length of family specific header
810  * @tb: destination array with maxtype+1 elements
811  * @maxtype: maximum attribute type to be expected
812  * @policy: validation policy
813  * @extack: extended ACK report struct
814  *
815  * See nla_parse_deprecated_strict()
816  */
817 static inline int
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)818 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
819 			      struct nlattr *tb[], int maxtype,
820 			      const struct nla_policy *policy,
821 			      struct netlink_ext_ack *extack)
822 {
823 	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
824 			     NL_VALIDATE_DEPRECATED_STRICT, extack);
825 }
826 
827 /**
828  * nlmsg_find_attr - find a specific attribute in a netlink message
829  * @nlh: netlink message header
830  * @hdrlen: length of family specific header
831  * @attrtype: type of attribute to look for
832  *
833  * Returns the first attribute which matches the specified type.
834  */
nlmsg_find_attr(const struct nlmsghdr * nlh,int hdrlen,int attrtype)835 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
836 					     int hdrlen, int attrtype)
837 {
838 	return nla_find(nlmsg_attrdata(nlh, hdrlen),
839 			nlmsg_attrlen(nlh, hdrlen), attrtype);
840 }
841 
842 /**
843  * nla_validate_deprecated - Validate a stream of attributes
844  * @head: head of attribute stream
845  * @len: length of attribute stream
846  * @maxtype: maximum attribute type to be expected
847  * @policy: validation policy
848  * @extack: extended ACK report struct
849  *
850  * Validates all attributes in the specified attribute stream against the
851  * specified policy. Validation is done in liberal mode.
852  * See documentation of struct nla_policy for more details.
853  *
854  * Returns 0 on success or a negative error code.
855  */
nla_validate_deprecated(const struct nlattr * head,int len,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)856 static inline int nla_validate_deprecated(const struct nlattr *head, int len,
857 					  int maxtype,
858 					  const struct nla_policy *policy,
859 					  struct netlink_ext_ack *extack)
860 {
861 	return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
862 			      extack);
863 }
864 
865 /**
866  * nla_validate - Validate a stream of attributes
867  * @head: head of attribute stream
868  * @len: length of attribute stream
869  * @maxtype: maximum attribute type to be expected
870  * @policy: validation policy
871  * @extack: extended ACK report struct
872  *
873  * Validates all attributes in the specified attribute stream against the
874  * specified policy. Validation is done in strict mode.
875  * See documentation of struct nla_policy for more details.
876  *
877  * Returns 0 on success or a negative error code.
878  */
nla_validate(const struct nlattr * head,int len,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)879 static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
880 			       const struct nla_policy *policy,
881 			       struct netlink_ext_ack *extack)
882 {
883 	return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
884 			      extack);
885 }
886 
887 /**
888  * nlmsg_validate_deprecated - validate a netlink message including attributes
889  * @nlh: netlinket message header
890  * @hdrlen: length of family specific header
891  * @maxtype: maximum attribute type to be expected
892  * @policy: validation policy
893  * @extack: extended ACK report struct
894  */
nlmsg_validate_deprecated(const struct nlmsghdr * nlh,int hdrlen,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)895 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
896 					    int hdrlen, int maxtype,
897 					    const struct nla_policy *policy,
898 					    struct netlink_ext_ack *extack)
899 {
900 	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
901 		return -EINVAL;
902 
903 	return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
904 			      nlmsg_attrlen(nlh, hdrlen), maxtype,
905 			      policy, NL_VALIDATE_LIBERAL, extack);
906 }
907 
908 
909 
910 /**
911  * nlmsg_report - need to report back to application?
912  * @nlh: netlink message header
913  *
914  * Returns 1 if a report back to the application is requested.
915  */
nlmsg_report(const struct nlmsghdr * nlh)916 static inline int nlmsg_report(const struct nlmsghdr *nlh)
917 {
918 	return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0;
919 }
920 
921 /**
922  * nlmsg_seq - return the seq number of netlink message
923  * @nlh: netlink message header
924  *
925  * Returns 0 if netlink message is NULL
926  */
nlmsg_seq(const struct nlmsghdr * nlh)927 static inline u32 nlmsg_seq(const struct nlmsghdr *nlh)
928 {
929 	return nlh ? nlh->nlmsg_seq : 0;
930 }
931 
932 /**
933  * nlmsg_for_each_attr - iterate over a stream of attributes
934  * @pos: loop counter, set to current attribute
935  * @nlh: netlink message header
936  * @hdrlen: length of family specific header
937  * @rem: initialized to len, holds bytes currently remaining in stream
938  */
939 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
940 	nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
941 			  nlmsg_attrlen(nlh, hdrlen), rem)
942 
943 /**
944  * nlmsg_put - Add a new netlink message to an skb
945  * @skb: socket buffer to store message in
946  * @portid: netlink PORTID of requesting application
947  * @seq: sequence number of message
948  * @type: message type
949  * @payload: length of message payload
950  * @flags: message flags
951  *
952  * Returns NULL if the tailroom of the skb is insufficient to store
953  * the message header and payload.
954  */
nlmsg_put(struct sk_buff * skb,u32 portid,u32 seq,int type,int payload,int flags)955 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
956 					 int type, int payload, int flags)
957 {
958 	if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
959 		return NULL;
960 
961 	return __nlmsg_put(skb, portid, seq, type, payload, flags);
962 }
963 
964 /**
965  * nlmsg_append - Add more data to a nlmsg in a skb
966  * @skb: socket buffer to store message in
967  * @size: length of message payload
968  *
969  * Append data to an existing nlmsg, used when constructing a message
970  * with multiple fixed-format headers (which is rare).
971  * Returns NULL if the tailroom of the skb is insufficient to store
972  * the extra payload.
973  */
nlmsg_append(struct sk_buff * skb,u32 size)974 static inline void *nlmsg_append(struct sk_buff *skb, u32 size)
975 {
976 	if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size)))
977 		return NULL;
978 
979 	if (NLMSG_ALIGN(size) - size)
980 		memset(skb_tail_pointer(skb) + size, 0,
981 		       NLMSG_ALIGN(size) - size);
982 	return __skb_put(skb, NLMSG_ALIGN(size));
983 }
984 
985 /**
986  * nlmsg_put_answer - Add a new callback based netlink message to an skb
987  * @skb: socket buffer to store message in
988  * @cb: netlink callback
989  * @type: message type
990  * @payload: length of message payload
991  * @flags: message flags
992  *
993  * Returns NULL if the tailroom of the skb is insufficient to store
994  * the message header and payload.
995  */
nlmsg_put_answer(struct sk_buff * skb,struct netlink_callback * cb,int type,int payload,int flags)996 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
997 						struct netlink_callback *cb,
998 						int type, int payload,
999 						int flags)
1000 {
1001 	return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1002 			 type, payload, flags);
1003 }
1004 
1005 /**
1006  * nlmsg_new - Allocate a new netlink message
1007  * @payload: size of the message payload
1008  * @flags: the type of memory to allocate.
1009  *
1010  * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
1011  * and a good default is needed.
1012  */
nlmsg_new(size_t payload,gfp_t flags)1013 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
1014 {
1015 	return alloc_skb(nlmsg_total_size(payload), flags);
1016 }
1017 
1018 /**
1019  * nlmsg_new_large - Allocate a new netlink message with non-contiguous
1020  * physical memory
1021  * @payload: size of the message payload
1022  *
1023  * The allocated skb is unable to have frag page for shinfo->frags*,
1024  * as the NULL setting for skb->head in netlink_skb_destructor() will
1025  * bypass most of the handling in skb_release_data()
1026  */
nlmsg_new_large(size_t payload)1027 static inline struct sk_buff *nlmsg_new_large(size_t payload)
1028 {
1029 	return netlink_alloc_large_skb(nlmsg_total_size(payload), 0);
1030 }
1031 
1032 /**
1033  * nlmsg_end - Finalize a netlink message
1034  * @skb: socket buffer the message is stored in
1035  * @nlh: netlink message header
1036  *
1037  * Corrects the netlink message header to include the appended
1038  * attributes. Only necessary if attributes have been added to
1039  * the message.
1040  */
nlmsg_end(struct sk_buff * skb,struct nlmsghdr * nlh)1041 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
1042 {
1043 	nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
1044 }
1045 
1046 /**
1047  * nlmsg_get_pos - return current position in netlink message
1048  * @skb: socket buffer the message is stored in
1049  *
1050  * Returns a pointer to the current tail of the message.
1051  */
nlmsg_get_pos(struct sk_buff * skb)1052 static inline void *nlmsg_get_pos(struct sk_buff *skb)
1053 {
1054 	return skb_tail_pointer(skb);
1055 }
1056 
1057 /**
1058  * nlmsg_trim - Trim message to a mark
1059  * @skb: socket buffer the message is stored in
1060  * @mark: mark to trim to
1061  *
1062  * Trims the message to the provided mark.
1063  */
nlmsg_trim(struct sk_buff * skb,const void * mark)1064 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
1065 {
1066 	if (mark) {
1067 		WARN_ON((unsigned char *) mark < skb->data);
1068 		skb_trim(skb, (unsigned char *) mark - skb->data);
1069 	}
1070 }
1071 
1072 /**
1073  * nlmsg_cancel - Cancel construction of a netlink message
1074  * @skb: socket buffer the message is stored in
1075  * @nlh: netlink message header
1076  *
1077  * Removes the complete netlink message including all
1078  * attributes from the socket buffer again.
1079  */
nlmsg_cancel(struct sk_buff * skb,struct nlmsghdr * nlh)1080 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
1081 {
1082 	nlmsg_trim(skb, nlh);
1083 }
1084 
1085 /**
1086  * nlmsg_free - drop a netlink message
1087  * @skb: socket buffer of netlink message
1088  */
nlmsg_free(struct sk_buff * skb)1089 static inline void nlmsg_free(struct sk_buff *skb)
1090 {
1091 	kfree_skb(skb);
1092 }
1093 
1094 /**
1095  * nlmsg_consume - free a netlink message
1096  * @skb: socket buffer of netlink message
1097  */
nlmsg_consume(struct sk_buff * skb)1098 static inline void nlmsg_consume(struct sk_buff *skb)
1099 {
1100 	consume_skb(skb);
1101 }
1102 
1103 /**
1104  * nlmsg_multicast_filtered - multicast a netlink message with filter function
1105  * @sk: netlink socket to spread messages to
1106  * @skb: netlink message as socket buffer
1107  * @portid: own netlink portid to avoid sending to yourself
1108  * @group: multicast group id
1109  * @flags: allocation flags
1110  * @filter: filter function
1111  * @filter_data: filter function private data
1112  *
1113  * Return: 0 on success, negative error code for failure.
1114  */
nlmsg_multicast_filtered(struct sock * sk,struct sk_buff * skb,u32 portid,unsigned int group,gfp_t flags,netlink_filter_fn filter,void * filter_data)1115 static inline int nlmsg_multicast_filtered(struct sock *sk, struct sk_buff *skb,
1116 					   u32 portid, unsigned int group,
1117 					   gfp_t flags,
1118 					   netlink_filter_fn filter,
1119 					   void *filter_data)
1120 {
1121 	int err;
1122 
1123 	NETLINK_CB(skb).dst_group = group;
1124 
1125 	err = netlink_broadcast_filtered(sk, skb, portid, group, flags,
1126 					 filter, filter_data);
1127 	if (err > 0)
1128 		err = 0;
1129 
1130 	return err;
1131 }
1132 
1133 /**
1134  * nlmsg_multicast - multicast a netlink message
1135  * @sk: netlink socket to spread messages to
1136  * @skb: netlink message as socket buffer
1137  * @portid: own netlink portid to avoid sending to yourself
1138  * @group: multicast group id
1139  * @flags: allocation flags
1140  */
nlmsg_multicast(struct sock * sk,struct sk_buff * skb,u32 portid,unsigned int group,gfp_t flags)1141 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1142 				  u32 portid, unsigned int group, gfp_t flags)
1143 {
1144 	return nlmsg_multicast_filtered(sk, skb, portid, group, flags,
1145 					NULL, NULL);
1146 }
1147 
1148 /**
1149  * nlmsg_unicast - unicast a netlink message
1150  * @sk: netlink socket to spread message to
1151  * @skb: netlink message as socket buffer
1152  * @portid: netlink portid of the destination socket
1153  */
nlmsg_unicast(struct sock * sk,struct sk_buff * skb,u32 portid)1154 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1155 {
1156 	int err;
1157 
1158 	err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1159 	if (err > 0)
1160 		err = 0;
1161 
1162 	return err;
1163 }
1164 
1165 /**
1166  * nlmsg_for_each_msg - iterate over a stream of messages
1167  * @pos: loop counter, set to current message
1168  * @head: head of message stream
1169  * @len: length of message stream
1170  * @rem: initialized to len, holds bytes currently remaining in stream
1171  */
1172 #define nlmsg_for_each_msg(pos, head, len, rem) \
1173 	for (pos = head, rem = len; \
1174 	     nlmsg_ok(pos, rem); \
1175 	     pos = nlmsg_next(pos, &(rem)))
1176 
1177 /**
1178  * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1179  * @cb: netlink callback structure that stores the sequence number
1180  * @nlh: netlink message header to write the flag to
1181  *
1182  * This function checks if the sequence (generation) number changed during dump
1183  * and if it did, advertises it in the netlink message header.
1184  *
1185  * The correct way to use it is to set cb->seq to the generation counter when
1186  * all locks for dumping have been acquired, and then call this function for
1187  * each message that is generated.
1188  *
1189  * Note that due to initialisation concerns, 0 is an invalid sequence number
1190  * and must not be used by code that uses this functionality.
1191  */
1192 static inline void
nl_dump_check_consistent(struct netlink_callback * cb,struct nlmsghdr * nlh)1193 nl_dump_check_consistent(struct netlink_callback *cb,
1194 			 struct nlmsghdr *nlh)
1195 {
1196 	if (cb->prev_seq && cb->seq != cb->prev_seq)
1197 		nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1198 	cb->prev_seq = cb->seq;
1199 }
1200 
1201 /**************************************************************************
1202  * Netlink Attributes
1203  **************************************************************************/
1204 
1205 /**
1206  * nla_attr_size - length of attribute not including padding
1207  * @payload: length of payload
1208  */
nla_attr_size(int payload)1209 static inline int nla_attr_size(int payload)
1210 {
1211 	return NLA_HDRLEN + payload;
1212 }
1213 
1214 /**
1215  * nla_total_size - total length of attribute including padding
1216  * @payload: length of payload
1217  */
nla_total_size(int payload)1218 static inline int nla_total_size(int payload)
1219 {
1220 	return NLA_ALIGN(nla_attr_size(payload));
1221 }
1222 
1223 /**
1224  * nla_padlen - length of padding at the tail of attribute
1225  * @payload: length of payload
1226  */
nla_padlen(int payload)1227 static inline int nla_padlen(int payload)
1228 {
1229 	return nla_total_size(payload) - nla_attr_size(payload);
1230 }
1231 
1232 /**
1233  * nla_type - attribute type
1234  * @nla: netlink attribute
1235  */
nla_type(const struct nlattr * nla)1236 static inline int nla_type(const struct nlattr *nla)
1237 {
1238 	return nla->nla_type & NLA_TYPE_MASK;
1239 }
1240 
1241 /**
1242  * nla_data - head of payload
1243  * @nla: netlink attribute
1244  */
nla_data(const struct nlattr * nla)1245 static inline void *nla_data(const struct nlattr *nla)
1246 {
1247 	return (char *) nla + NLA_HDRLEN;
1248 }
1249 
1250 /**
1251  * nla_len - length of payload
1252  * @nla: netlink attribute
1253  */
nla_len(const struct nlattr * nla)1254 static inline u16 nla_len(const struct nlattr *nla)
1255 {
1256 	return nla->nla_len - NLA_HDRLEN;
1257 }
1258 
1259 /**
1260  * nla_ok - check if the netlink attribute fits into the remaining bytes
1261  * @nla: netlink attribute
1262  * @remaining: number of bytes remaining in attribute stream
1263  */
nla_ok(const struct nlattr * nla,int remaining)1264 static inline int nla_ok(const struct nlattr *nla, int remaining)
1265 {
1266 	return remaining >= (int) sizeof(*nla) &&
1267 	       nla->nla_len >= sizeof(*nla) &&
1268 	       nla->nla_len <= remaining;
1269 }
1270 
1271 /**
1272  * nla_next - next netlink attribute in attribute stream
1273  * @nla: netlink attribute
1274  * @remaining: number of bytes remaining in attribute stream
1275  *
1276  * Returns the next netlink attribute in the attribute stream and
1277  * decrements remaining by the size of the current attribute.
1278  */
nla_next(const struct nlattr * nla,int * remaining)1279 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1280 {
1281 	unsigned int totlen = NLA_ALIGN(nla->nla_len);
1282 
1283 	*remaining -= totlen;
1284 	return (struct nlattr *) ((char *) nla + totlen);
1285 }
1286 
1287 /**
1288  * nla_find_nested - find attribute in a set of nested attributes
1289  * @nla: attribute containing the nested attributes
1290  * @attrtype: type of attribute to look for
1291  *
1292  * Returns the first attribute which matches the specified type.
1293  */
1294 static inline struct nlattr *
nla_find_nested(const struct nlattr * nla,int attrtype)1295 nla_find_nested(const struct nlattr *nla, int attrtype)
1296 {
1297 	return nla_find(nla_data(nla), nla_len(nla), attrtype);
1298 }
1299 
1300 /**
1301  * nla_parse_nested - parse nested attributes
1302  * @tb: destination array with maxtype+1 elements
1303  * @maxtype: maximum attribute type to be expected
1304  * @nla: attribute containing the nested attributes
1305  * @policy: validation policy
1306  * @extack: extended ACK report struct
1307  *
1308  * See nla_parse()
1309  */
nla_parse_nested(struct nlattr * tb[],int maxtype,const struct nlattr * nla,const struct nla_policy * policy,struct netlink_ext_ack * extack)1310 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1311 				   const struct nlattr *nla,
1312 				   const struct nla_policy *policy,
1313 				   struct netlink_ext_ack *extack)
1314 {
1315 	if (!(nla->nla_type & NLA_F_NESTED)) {
1316 		NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1317 		return -EINVAL;
1318 	}
1319 
1320 	return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1321 			   NL_VALIDATE_STRICT, extack);
1322 }
1323 
1324 /**
1325  * nla_parse_nested_deprecated - parse nested attributes
1326  * @tb: destination array with maxtype+1 elements
1327  * @maxtype: maximum attribute type to be expected
1328  * @nla: attribute containing the nested attributes
1329  * @policy: validation policy
1330  * @extack: extended ACK report struct
1331  *
1332  * See nla_parse_deprecated()
1333  */
nla_parse_nested_deprecated(struct nlattr * tb[],int maxtype,const struct nlattr * nla,const struct nla_policy * policy,struct netlink_ext_ack * extack)1334 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1335 					      const struct nlattr *nla,
1336 					      const struct nla_policy *policy,
1337 					      struct netlink_ext_ack *extack)
1338 {
1339 	return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1340 			   NL_VALIDATE_LIBERAL, extack);
1341 }
1342 
1343 /**
1344  * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1345  * @skb: socket buffer to add attribute to
1346  * @attrtype: attribute type
1347  * @value: numeric value
1348  */
nla_put_u8(struct sk_buff * skb,int attrtype,u8 value)1349 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1350 {
1351 	/* temporary variables to work around GCC PR81715 with asan-stack=1 */
1352 	u8 tmp = value;
1353 
1354 	return nla_put(skb, attrtype, sizeof(u8), &tmp);
1355 }
1356 
1357 /**
1358  * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1359  * @skb: socket buffer to add attribute to
1360  * @attrtype: attribute type
1361  * @value: numeric value
1362  */
nla_put_u16(struct sk_buff * skb,int attrtype,u16 value)1363 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1364 {
1365 	u16 tmp = value;
1366 
1367 	return nla_put(skb, attrtype, sizeof(u16), &tmp);
1368 }
1369 
1370 /**
1371  * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1372  * @skb: socket buffer to add attribute to
1373  * @attrtype: attribute type
1374  * @value: numeric value
1375  */
nla_put_be16(struct sk_buff * skb,int attrtype,__be16 value)1376 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1377 {
1378 	__be16 tmp = value;
1379 
1380 	return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1381 }
1382 
1383 /**
1384  * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1385  * @skb: socket buffer to add attribute to
1386  * @attrtype: attribute type
1387  * @value: numeric value
1388  */
nla_put_net16(struct sk_buff * skb,int attrtype,__be16 value)1389 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1390 {
1391 	__be16 tmp = value;
1392 
1393 	return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1394 }
1395 
1396 /**
1397  * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1398  * @skb: socket buffer to add attribute to
1399  * @attrtype: attribute type
1400  * @value: numeric value
1401  */
nla_put_le16(struct sk_buff * skb,int attrtype,__le16 value)1402 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1403 {
1404 	__le16 tmp = value;
1405 
1406 	return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1407 }
1408 
1409 /**
1410  * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1411  * @skb: socket buffer to add attribute to
1412  * @attrtype: attribute type
1413  * @value: numeric value
1414  */
nla_put_u32(struct sk_buff * skb,int attrtype,u32 value)1415 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1416 {
1417 	u32 tmp = value;
1418 
1419 	return nla_put(skb, attrtype, sizeof(u32), &tmp);
1420 }
1421 
1422 /**
1423  * nla_put_uint - Add a variable-size unsigned int to a socket buffer
1424  * @skb: socket buffer to add attribute to
1425  * @attrtype: attribute type
1426  * @value: numeric value
1427  */
nla_put_uint(struct sk_buff * skb,int attrtype,u64 value)1428 static inline int nla_put_uint(struct sk_buff *skb, int attrtype, u64 value)
1429 {
1430 	u64 tmp64 = value;
1431 	u32 tmp32 = value;
1432 
1433 	if (tmp64 == tmp32)
1434 		return nla_put_u32(skb, attrtype, tmp32);
1435 	return nla_put(skb, attrtype, sizeof(u64), &tmp64);
1436 }
1437 
1438 /**
1439  * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1440  * @skb: socket buffer to add attribute to
1441  * @attrtype: attribute type
1442  * @value: numeric value
1443  */
nla_put_be32(struct sk_buff * skb,int attrtype,__be32 value)1444 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1445 {
1446 	__be32 tmp = value;
1447 
1448 	return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1449 }
1450 
1451 /**
1452  * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1453  * @skb: socket buffer to add attribute to
1454  * @attrtype: attribute type
1455  * @value: numeric value
1456  */
nla_put_net32(struct sk_buff * skb,int attrtype,__be32 value)1457 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1458 {
1459 	__be32 tmp = value;
1460 
1461 	return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1462 }
1463 
1464 /**
1465  * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1466  * @skb: socket buffer to add attribute to
1467  * @attrtype: attribute type
1468  * @value: numeric value
1469  */
nla_put_le32(struct sk_buff * skb,int attrtype,__le32 value)1470 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1471 {
1472 	__le32 tmp = value;
1473 
1474 	return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1475 }
1476 
1477 /**
1478  * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1479  * @skb: socket buffer to add attribute to
1480  * @attrtype: attribute type
1481  * @value: numeric value
1482  * @padattr: attribute type for the padding
1483  */
nla_put_u64_64bit(struct sk_buff * skb,int attrtype,u64 value,int padattr)1484 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1485 				    u64 value, int padattr)
1486 {
1487 	u64 tmp = value;
1488 
1489 	return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1490 }
1491 
1492 /**
1493  * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it
1494  * @skb: socket buffer to add attribute to
1495  * @attrtype: attribute type
1496  * @value: numeric value
1497  * @padattr: attribute type for the padding
1498  */
nla_put_be64(struct sk_buff * skb,int attrtype,__be64 value,int padattr)1499 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value,
1500 			       int padattr)
1501 {
1502 	__be64 tmp = value;
1503 
1504 	return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1505 }
1506 
1507 /**
1508  * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it
1509  * @skb: socket buffer to add attribute to
1510  * @attrtype: attribute type
1511  * @value: numeric value
1512  * @padattr: attribute type for the padding
1513  */
nla_put_net64(struct sk_buff * skb,int attrtype,__be64 value,int padattr)1514 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value,
1515 				int padattr)
1516 {
1517 	__be64 tmp = value;
1518 
1519 	return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1520 			    padattr);
1521 }
1522 
1523 /**
1524  * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1525  * @skb: socket buffer to add attribute to
1526  * @attrtype: attribute type
1527  * @value: numeric value
1528  * @padattr: attribute type for the padding
1529  */
nla_put_le64(struct sk_buff * skb,int attrtype,__le64 value,int padattr)1530 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1531 			       int padattr)
1532 {
1533 	__le64 tmp = value;
1534 
1535 	return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1536 }
1537 
1538 /**
1539  * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1540  * @skb: socket buffer to add attribute to
1541  * @attrtype: attribute type
1542  * @value: numeric value
1543  */
nla_put_s8(struct sk_buff * skb,int attrtype,s8 value)1544 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1545 {
1546 	s8 tmp = value;
1547 
1548 	return nla_put(skb, attrtype, sizeof(s8), &tmp);
1549 }
1550 
1551 /**
1552  * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1553  * @skb: socket buffer to add attribute to
1554  * @attrtype: attribute type
1555  * @value: numeric value
1556  */
nla_put_s16(struct sk_buff * skb,int attrtype,s16 value)1557 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1558 {
1559 	s16 tmp = value;
1560 
1561 	return nla_put(skb, attrtype, sizeof(s16), &tmp);
1562 }
1563 
1564 /**
1565  * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1566  * @skb: socket buffer to add attribute to
1567  * @attrtype: attribute type
1568  * @value: numeric value
1569  */
nla_put_s32(struct sk_buff * skb,int attrtype,s32 value)1570 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1571 {
1572 	s32 tmp = value;
1573 
1574 	return nla_put(skb, attrtype, sizeof(s32), &tmp);
1575 }
1576 
1577 /**
1578  * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1579  * @skb: socket buffer to add attribute to
1580  * @attrtype: attribute type
1581  * @value: numeric value
1582  * @padattr: attribute type for the padding
1583  */
nla_put_s64(struct sk_buff * skb,int attrtype,s64 value,int padattr)1584 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1585 			      int padattr)
1586 {
1587 	s64 tmp = value;
1588 
1589 	return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1590 }
1591 
1592 /**
1593  * nla_put_sint - Add a variable-size signed int to a socket buffer
1594  * @skb: socket buffer to add attribute to
1595  * @attrtype: attribute type
1596  * @value: numeric value
1597  */
nla_put_sint(struct sk_buff * skb,int attrtype,s64 value)1598 static inline int nla_put_sint(struct sk_buff *skb, int attrtype, s64 value)
1599 {
1600 	s64 tmp64 = value;
1601 	s32 tmp32 = value;
1602 
1603 	if (tmp64 == tmp32)
1604 		return nla_put_s32(skb, attrtype, tmp32);
1605 	return nla_put(skb, attrtype, sizeof(s64), &tmp64);
1606 }
1607 
1608 /**
1609  * nla_put_string - Add a string netlink attribute to a socket buffer
1610  * @skb: socket buffer to add attribute to
1611  * @attrtype: attribute type
1612  * @str: NUL terminated string
1613  */
nla_put_string(struct sk_buff * skb,int attrtype,const char * str)1614 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1615 				 const char *str)
1616 {
1617 	return nla_put(skb, attrtype, strlen(str) + 1, str);
1618 }
1619 
1620 /**
1621  * nla_put_flag - Add a flag netlink attribute to a socket buffer
1622  * @skb: socket buffer to add attribute to
1623  * @attrtype: attribute type
1624  */
nla_put_flag(struct sk_buff * skb,int attrtype)1625 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1626 {
1627 	return nla_put(skb, attrtype, 0, NULL);
1628 }
1629 
1630 /**
1631  * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1632  * @skb: socket buffer to add attribute to
1633  * @attrtype: attribute type
1634  * @njiffies: number of jiffies to convert to msecs
1635  * @padattr: attribute type for the padding
1636  */
nla_put_msecs(struct sk_buff * skb,int attrtype,unsigned long njiffies,int padattr)1637 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1638 				unsigned long njiffies, int padattr)
1639 {
1640 	u64 tmp = jiffies_to_msecs(njiffies);
1641 
1642 	return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1643 }
1644 
1645 /**
1646  * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1647  * buffer
1648  * @skb: socket buffer to add attribute to
1649  * @attrtype: attribute type
1650  * @addr: IPv4 address
1651  */
nla_put_in_addr(struct sk_buff * skb,int attrtype,__be32 addr)1652 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1653 				  __be32 addr)
1654 {
1655 	__be32 tmp = addr;
1656 
1657 	return nla_put_be32(skb, attrtype, tmp);
1658 }
1659 
1660 /**
1661  * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1662  * buffer
1663  * @skb: socket buffer to add attribute to
1664  * @attrtype: attribute type
1665  * @addr: IPv6 address
1666  */
nla_put_in6_addr(struct sk_buff * skb,int attrtype,const struct in6_addr * addr)1667 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1668 				   const struct in6_addr *addr)
1669 {
1670 	return nla_put(skb, attrtype, sizeof(*addr), addr);
1671 }
1672 
1673 /**
1674  * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1675  * @skb: socket buffer to add attribute to
1676  * @attrtype: attribute type
1677  * @value: value carrying bits
1678  * @selector: selector of valid bits
1679  */
nla_put_bitfield32(struct sk_buff * skb,int attrtype,__u32 value,__u32 selector)1680 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1681 				     __u32 value, __u32 selector)
1682 {
1683 	struct nla_bitfield32 tmp = { value, selector, };
1684 
1685 	return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1686 }
1687 
1688 /**
1689  * nla_get_u32 - return payload of u32 attribute
1690  * @nla: u32 netlink attribute
1691  */
nla_get_u32(const struct nlattr * nla)1692 static inline u32 nla_get_u32(const struct nlattr *nla)
1693 {
1694 	return *(u32 *) nla_data(nla);
1695 }
1696 
1697 /**
1698  * nla_get_be32 - return payload of __be32 attribute
1699  * @nla: __be32 netlink attribute
1700  */
nla_get_be32(const struct nlattr * nla)1701 static inline __be32 nla_get_be32(const struct nlattr *nla)
1702 {
1703 	return *(__be32 *) nla_data(nla);
1704 }
1705 
1706 /**
1707  * nla_get_le32 - return payload of __le32 attribute
1708  * @nla: __le32 netlink attribute
1709  */
nla_get_le32(const struct nlattr * nla)1710 static inline __le32 nla_get_le32(const struct nlattr *nla)
1711 {
1712 	return *(__le32 *) nla_data(nla);
1713 }
1714 
1715 /**
1716  * nla_get_u16 - return payload of u16 attribute
1717  * @nla: u16 netlink attribute
1718  */
nla_get_u16(const struct nlattr * nla)1719 static inline u16 nla_get_u16(const struct nlattr *nla)
1720 {
1721 	return *(u16 *) nla_data(nla);
1722 }
1723 
1724 /**
1725  * nla_get_be16 - return payload of __be16 attribute
1726  * @nla: __be16 netlink attribute
1727  */
nla_get_be16(const struct nlattr * nla)1728 static inline __be16 nla_get_be16(const struct nlattr *nla)
1729 {
1730 	return *(__be16 *) nla_data(nla);
1731 }
1732 
1733 /**
1734  * nla_get_le16 - return payload of __le16 attribute
1735  * @nla: __le16 netlink attribute
1736  */
nla_get_le16(const struct nlattr * nla)1737 static inline __le16 nla_get_le16(const struct nlattr *nla)
1738 {
1739 	return *(__le16 *) nla_data(nla);
1740 }
1741 
1742 /**
1743  * nla_get_u8 - return payload of u8 attribute
1744  * @nla: u8 netlink attribute
1745  */
nla_get_u8(const struct nlattr * nla)1746 static inline u8 nla_get_u8(const struct nlattr *nla)
1747 {
1748 	return *(u8 *) nla_data(nla);
1749 }
1750 
1751 /**
1752  * nla_get_u64 - return payload of u64 attribute
1753  * @nla: u64 netlink attribute
1754  */
nla_get_u64(const struct nlattr * nla)1755 static inline u64 nla_get_u64(const struct nlattr *nla)
1756 {
1757 	u64 tmp;
1758 
1759 	nla_memcpy(&tmp, nla, sizeof(tmp));
1760 
1761 	return tmp;
1762 }
1763 
1764 /**
1765  * nla_get_uint - return payload of uint attribute
1766  * @nla: uint netlink attribute
1767  */
nla_get_uint(const struct nlattr * nla)1768 static inline u64 nla_get_uint(const struct nlattr *nla)
1769 {
1770 	if (nla_len(nla) == sizeof(u32))
1771 		return nla_get_u32(nla);
1772 	return nla_get_u64(nla);
1773 }
1774 
1775 /**
1776  * nla_get_be64 - return payload of __be64 attribute
1777  * @nla: __be64 netlink attribute
1778  */
nla_get_be64(const struct nlattr * nla)1779 static inline __be64 nla_get_be64(const struct nlattr *nla)
1780 {
1781 	__be64 tmp;
1782 
1783 	nla_memcpy(&tmp, nla, sizeof(tmp));
1784 
1785 	return tmp;
1786 }
1787 
1788 /**
1789  * nla_get_le64 - return payload of __le64 attribute
1790  * @nla: __le64 netlink attribute
1791  */
nla_get_le64(const struct nlattr * nla)1792 static inline __le64 nla_get_le64(const struct nlattr *nla)
1793 {
1794 	return *(__le64 *) nla_data(nla);
1795 }
1796 
1797 /**
1798  * nla_get_s32 - return payload of s32 attribute
1799  * @nla: s32 netlink attribute
1800  */
nla_get_s32(const struct nlattr * nla)1801 static inline s32 nla_get_s32(const struct nlattr *nla)
1802 {
1803 	return *(s32 *) nla_data(nla);
1804 }
1805 
1806 /**
1807  * nla_get_s16 - return payload of s16 attribute
1808  * @nla: s16 netlink attribute
1809  */
nla_get_s16(const struct nlattr * nla)1810 static inline s16 nla_get_s16(const struct nlattr *nla)
1811 {
1812 	return *(s16 *) nla_data(nla);
1813 }
1814 
1815 /**
1816  * nla_get_s8 - return payload of s8 attribute
1817  * @nla: s8 netlink attribute
1818  */
nla_get_s8(const struct nlattr * nla)1819 static inline s8 nla_get_s8(const struct nlattr *nla)
1820 {
1821 	return *(s8 *) nla_data(nla);
1822 }
1823 
1824 /**
1825  * nla_get_s64 - return payload of s64 attribute
1826  * @nla: s64 netlink attribute
1827  */
nla_get_s64(const struct nlattr * nla)1828 static inline s64 nla_get_s64(const struct nlattr *nla)
1829 {
1830 	s64 tmp;
1831 
1832 	nla_memcpy(&tmp, nla, sizeof(tmp));
1833 
1834 	return tmp;
1835 }
1836 
1837 /**
1838  * nla_get_sint - return payload of uint attribute
1839  * @nla: uint netlink attribute
1840  */
nla_get_sint(const struct nlattr * nla)1841 static inline s64 nla_get_sint(const struct nlattr *nla)
1842 {
1843 	if (nla_len(nla) == sizeof(s32))
1844 		return nla_get_s32(nla);
1845 	return nla_get_s64(nla);
1846 }
1847 
1848 /**
1849  * nla_get_flag - return payload of flag attribute
1850  * @nla: flag netlink attribute
1851  */
nla_get_flag(const struct nlattr * nla)1852 static inline int nla_get_flag(const struct nlattr *nla)
1853 {
1854 	return !!nla;
1855 }
1856 
1857 /**
1858  * nla_get_msecs - return payload of msecs attribute
1859  * @nla: msecs netlink attribute
1860  *
1861  * Returns the number of milliseconds in jiffies.
1862  */
nla_get_msecs(const struct nlattr * nla)1863 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1864 {
1865 	u64 msecs = nla_get_u64(nla);
1866 
1867 	return msecs_to_jiffies((unsigned long) msecs);
1868 }
1869 
1870 /**
1871  * nla_get_in_addr - return payload of IPv4 address attribute
1872  * @nla: IPv4 address netlink attribute
1873  */
nla_get_in_addr(const struct nlattr * nla)1874 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1875 {
1876 	return *(__be32 *) nla_data(nla);
1877 }
1878 
1879 /**
1880  * nla_get_in6_addr - return payload of IPv6 address attribute
1881  * @nla: IPv6 address netlink attribute
1882  */
nla_get_in6_addr(const struct nlattr * nla)1883 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1884 {
1885 	struct in6_addr tmp;
1886 
1887 	nla_memcpy(&tmp, nla, sizeof(tmp));
1888 	return tmp;
1889 }
1890 
1891 /**
1892  * nla_get_bitfield32 - return payload of 32 bitfield attribute
1893  * @nla: nla_bitfield32 attribute
1894  */
nla_get_bitfield32(const struct nlattr * nla)1895 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1896 {
1897 	struct nla_bitfield32 tmp;
1898 
1899 	nla_memcpy(&tmp, nla, sizeof(tmp));
1900 	return tmp;
1901 }
1902 
1903 /**
1904  * nla_memdup - duplicate attribute memory (kmemdup)
1905  * @src: netlink attribute to duplicate from
1906  * @gfp: GFP mask
1907  */
nla_memdup_noprof(const struct nlattr * src,gfp_t gfp)1908 static inline void *nla_memdup_noprof(const struct nlattr *src, gfp_t gfp)
1909 {
1910 	return kmemdup_noprof(nla_data(src), nla_len(src), gfp);
1911 }
1912 #define nla_memdup(...)	alloc_hooks(nla_memdup_noprof(__VA_ARGS__))
1913 
1914 /**
1915  * nla_nest_start_noflag - Start a new level of nested attributes
1916  * @skb: socket buffer to add attributes to
1917  * @attrtype: attribute type of container
1918  *
1919  * This function exists for backward compatibility to use in APIs which never
1920  * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1921  * nla_nest_start() which sets the flag.
1922  *
1923  * Returns the container attribute or NULL on error
1924  */
nla_nest_start_noflag(struct sk_buff * skb,int attrtype)1925 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1926 						   int attrtype)
1927 {
1928 	struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1929 
1930 	if (nla_put(skb, attrtype, 0, NULL) < 0)
1931 		return NULL;
1932 
1933 	return start;
1934 }
1935 
1936 /**
1937  * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1938  * @skb: socket buffer to add attributes to
1939  * @attrtype: attribute type of container
1940  *
1941  * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1942  * flag. This is the preferred function to use in new code.
1943  *
1944  * Returns the container attribute or NULL on error
1945  */
nla_nest_start(struct sk_buff * skb,int attrtype)1946 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1947 {
1948 	return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1949 }
1950 
1951 /**
1952  * nla_nest_end - Finalize nesting of attributes
1953  * @skb: socket buffer the attributes are stored in
1954  * @start: container attribute
1955  *
1956  * Corrects the container attribute header to include the all
1957  * appended attributes.
1958  *
1959  * Returns the total data length of the skb.
1960  */
nla_nest_end(struct sk_buff * skb,struct nlattr * start)1961 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1962 {
1963 	start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1964 	return skb->len;
1965 }
1966 
1967 /**
1968  * nla_nest_cancel - Cancel nesting of attributes
1969  * @skb: socket buffer the message is stored in
1970  * @start: container attribute
1971  *
1972  * Removes the container attribute and including all nested
1973  * attributes. Returns -EMSGSIZE
1974  */
nla_nest_cancel(struct sk_buff * skb,struct nlattr * start)1975 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1976 {
1977 	nlmsg_trim(skb, start);
1978 }
1979 
1980 /**
1981  * __nla_validate_nested - Validate a stream of nested attributes
1982  * @start: container attribute
1983  * @maxtype: maximum attribute type to be expected
1984  * @policy: validation policy
1985  * @validate: validation strictness
1986  * @extack: extended ACK report struct
1987  *
1988  * Validates all attributes in the nested attribute stream against the
1989  * specified policy. Attributes with a type exceeding maxtype will be
1990  * ignored. See documentation of struct nla_policy for more details.
1991  *
1992  * Returns 0 on success or a negative error code.
1993  */
__nla_validate_nested(const struct nlattr * start,int maxtype,const struct nla_policy * policy,unsigned int validate,struct netlink_ext_ack * extack)1994 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1995 					const struct nla_policy *policy,
1996 					unsigned int validate,
1997 					struct netlink_ext_ack *extack)
1998 {
1999 	return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
2000 			      validate, extack);
2001 }
2002 
2003 static inline int
nla_validate_nested(const struct nlattr * start,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)2004 nla_validate_nested(const struct nlattr *start, int maxtype,
2005 		    const struct nla_policy *policy,
2006 		    struct netlink_ext_ack *extack)
2007 {
2008 	return __nla_validate_nested(start, maxtype, policy,
2009 				     NL_VALIDATE_STRICT, extack);
2010 }
2011 
2012 static inline int
nla_validate_nested_deprecated(const struct nlattr * start,int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)2013 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
2014 			       const struct nla_policy *policy,
2015 			       struct netlink_ext_ack *extack)
2016 {
2017 	return __nla_validate_nested(start, maxtype, policy,
2018 				     NL_VALIDATE_LIBERAL, extack);
2019 }
2020 
2021 /**
2022  * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
2023  * @skb: socket buffer the message is stored in
2024  *
2025  * Return true if padding is needed to align the next attribute (nla_data()) to
2026  * a 64-bit aligned area.
2027  */
nla_need_padding_for_64bit(struct sk_buff * skb)2028 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
2029 {
2030 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2031 	/* The nlattr header is 4 bytes in size, that's why we test
2032 	 * if the skb->data _is_ aligned.  A NOP attribute, plus
2033 	 * nlattr header for next attribute, will make nla_data()
2034 	 * 8-byte aligned.
2035 	 */
2036 	if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
2037 		return true;
2038 #endif
2039 	return false;
2040 }
2041 
2042 /**
2043  * nla_align_64bit - 64-bit align the nla_data() of next attribute
2044  * @skb: socket buffer the message is stored in
2045  * @padattr: attribute type for the padding
2046  *
2047  * Conditionally emit a padding netlink attribute in order to make
2048  * the next attribute we emit have a 64-bit aligned nla_data() area.
2049  * This will only be done in architectures which do not have
2050  * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
2051  *
2052  * Returns zero on success or a negative error code.
2053  */
nla_align_64bit(struct sk_buff * skb,int padattr)2054 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
2055 {
2056 	if (nla_need_padding_for_64bit(skb) &&
2057 	    !nla_reserve(skb, padattr, 0))
2058 		return -EMSGSIZE;
2059 
2060 	return 0;
2061 }
2062 
2063 /**
2064  * nla_total_size_64bit - total length of attribute including padding
2065  * @payload: length of payload
2066  */
nla_total_size_64bit(int payload)2067 static inline int nla_total_size_64bit(int payload)
2068 {
2069 	return NLA_ALIGN(nla_attr_size(payload))
2070 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2071 		+ NLA_ALIGN(nla_attr_size(0))
2072 #endif
2073 		;
2074 }
2075 
2076 /**
2077  * nla_for_each_attr - iterate over a stream of attributes
2078  * @pos: loop counter, set to current attribute
2079  * @head: head of attribute stream
2080  * @len: length of attribute stream
2081  * @rem: initialized to len, holds bytes currently remaining in stream
2082  */
2083 #define nla_for_each_attr(pos, head, len, rem) \
2084 	for (pos = head, rem = len; \
2085 	     nla_ok(pos, rem); \
2086 	     pos = nla_next(pos, &(rem)))
2087 
2088 /**
2089  * nla_for_each_attr_type - iterate over a stream of attributes
2090  * @pos: loop counter, set to current attribute
2091  * @type: required attribute type for @pos
2092  * @head: head of attribute stream
2093  * @len: length of attribute stream
2094  * @rem: initialized to len, holds bytes currently remaining in stream
2095  */
2096 #define nla_for_each_attr_type(pos, type, head, len, rem) \
2097 	nla_for_each_attr(pos, head, len, rem) \
2098 		if (nla_type(pos) == type)
2099 
2100 /**
2101  * nla_for_each_nested - iterate over nested attributes
2102  * @pos: loop counter, set to current attribute
2103  * @nla: attribute containing the nested attributes
2104  * @rem: initialized to len, holds bytes currently remaining in stream
2105  */
2106 #define nla_for_each_nested(pos, nla, rem) \
2107 	nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
2108 
2109 /**
2110  * nla_for_each_nested_type - iterate over nested attributes
2111  * @pos: loop counter, set to current attribute
2112  * @type: required attribute type for @pos
2113  * @nla: attribute containing the nested attributes
2114  * @rem: initialized to len, holds bytes currently remaining in stream
2115  */
2116 #define nla_for_each_nested_type(pos, type, nla, rem) \
2117 	nla_for_each_nested(pos, nla, rem) \
2118 		if (nla_type(pos) == type)
2119 
2120 /**
2121  * nla_is_last - Test if attribute is last in stream
2122  * @nla: attribute to test
2123  * @rem: bytes remaining in stream
2124  */
nla_is_last(const struct nlattr * nla,int rem)2125 static inline bool nla_is_last(const struct nlattr *nla, int rem)
2126 {
2127 	return nla->nla_len == rem;
2128 }
2129 
2130 void nla_get_range_unsigned(const struct nla_policy *pt,
2131 			    struct netlink_range_validation *range);
2132 void nla_get_range_signed(const struct nla_policy *pt,
2133 			  struct netlink_range_validation_signed *range);
2134 
2135 struct netlink_policy_dump_state;
2136 
2137 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
2138 				   const struct nla_policy *policy,
2139 				   unsigned int maxtype);
2140 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
2141 				       const struct nla_policy *policy,
2142 				       unsigned int maxtype);
2143 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state);
2144 int netlink_policy_dump_write(struct sk_buff *skb,
2145 			      struct netlink_policy_dump_state *state);
2146 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt);
2147 int netlink_policy_dump_write_attr(struct sk_buff *skb,
2148 				   const struct nla_policy *pt,
2149 				   int nestattr);
2150 void netlink_policy_dump_free(struct netlink_policy_dump_state *state);
2151 
2152 #endif
2153