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