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