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_strlcpy(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_EXACT_LEN,
 185	NLA_MIN_LEN,
 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_MIN,
 203	NLA_VALIDATE_MAX,
 204	NLA_VALIDATE_RANGE_PTR,
 205	NLA_VALIDATE_FUNCTION,
 206	NLA_VALIDATE_WARN_TOO_LONG,
 207};
 208
 209/**
 210 * struct nla_policy - attribute validation policy
 211 * @type: Type of attribute or NLA_UNSPEC
 212 * @validation_type: type of attribute validation done in addition to
 213 *	type-specific validation (e.g. range, function call), see
 214 *	&enum nla_policy_validation
 215 * @len: Type specific length of payload
 216 *
 217 * Policies are defined as arrays of this struct, the array must be
 218 * accessible by attribute type up to the highest identifier to be expected.
 219 *
 220 * Meaning of `len' field:
 221 *    NLA_STRING           Maximum length of string
 222 *    NLA_NUL_STRING       Maximum length of string (excluding NUL)
 223 *    NLA_FLAG             Unused
 224 *    NLA_BINARY           Maximum length of attribute payload
 225 *    NLA_MIN_LEN          Minimum length of attribute payload
 226 *    NLA_NESTED,
 227 *    NLA_NESTED_ARRAY     Length verification is done by checking len of
 228 *                         nested header (or empty); len field is used if
 229 *                         nested_policy is also used, for the max attr
 230 *                         number in the nested policy.
 231 *    NLA_U8, NLA_U16,
 232 *    NLA_U32, NLA_U64,
 233 *    NLA_S8, NLA_S16,
 234 *    NLA_S32, NLA_S64,
 235 *    NLA_MSECS            Leaving the length field zero will verify the
 236 *                         given type fits, using it verifies minimum length
 237 *                         just like "All other"
 238 *    NLA_BITFIELD32       Unused
 239 *    NLA_REJECT           Unused
 240 *    NLA_EXACT_LEN        Attribute should have exactly this length, otherwise
 241 *                         it is rejected or warned about, the latter happening
 242 *                         if and only if the `validation_type' is set to
 243 *                         NLA_VALIDATE_WARN_TOO_LONG.
 244 *    NLA_MIN_LEN          Minimum length of attribute payload
 245 *    All other            Minimum length of attribute payload
 246 *
 247 * Meaning of validation union:
 248 *    NLA_BITFIELD32       This is a 32-bit bitmap/bitselector attribute and
 249 *                         `bitfield32_valid' is the u32 value of valid flags
 250 *    NLA_REJECT           This attribute is always rejected and `reject_message'
 251 *                         may point to a string to report as the error instead
 252 *                         of the generic one in extended ACK.
 253 *    NLA_NESTED           `nested_policy' to a nested policy to validate, must
 254 *                         also set `len' to the max attribute number. Use the
 255 *                         provided NLA_POLICY_NESTED() macro.
 256 *                         Note that nla_parse() will validate, but of course not
 257 *                         parse, the nested sub-policies.
 258 *    NLA_NESTED_ARRAY     `nested_policy' points to a nested policy to validate,
 259 *                         must also set `len' to the max attribute number. Use
 260 *                         the provided NLA_POLICY_NESTED_ARRAY() macro.
 261 *                         The difference to NLA_NESTED is the structure:
 262 *                         NLA_NESTED has the nested attributes directly inside
 263 *                         while an array has the nested attributes at another
 264 *                         level down and the attribute types directly in the
 265 *                         nesting don't matter.
 266 *    NLA_U8,
 267 *    NLA_U16,
 268 *    NLA_U32,
 269 *    NLA_U64,
 270 *    NLA_S8,
 271 *    NLA_S16,
 272 *    NLA_S32,
 273 *    NLA_S64              The `min' and `max' fields are used depending on the
 274 *                         validation_type field, if that is min/max/range then
 275 *                         the min, max or both are used (respectively) to check
 276 *                         the value of the integer attribute.
 277 *                         Note that in the interest of code simplicity and
 278 *                         struct size both limits are s16, so you cannot
 279 *                         enforce a range that doesn't fall within the range
 280 *                         of s16 - do that as usual in the code instead.
 281 *                         Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
 282 *                         NLA_POLICY_RANGE() macros.
 283 *    NLA_U8,
 284 *    NLA_U16,
 285 *    NLA_U32,
 286 *    NLA_U64              If the validation_type field instead is set to
 287 *                         NLA_VALIDATE_RANGE_PTR, `range' must be a pointer
 288 *                         to a struct netlink_range_validation that indicates
 289 *                         the min/max values.
 290 *                         Use NLA_POLICY_FULL_RANGE().
 291 *    NLA_S8,
 292 *    NLA_S16,
 293 *    NLA_S32,
 294 *    NLA_S64              If the validation_type field instead is set to
 295 *                         NLA_VALIDATE_RANGE_PTR, `range_signed' must be a
 296 *                         pointer to a struct netlink_range_validation_signed
 297 *                         that indicates the min/max values.
 298 *                         Use NLA_POLICY_FULL_RANGE_SIGNED().
 299 *    All other            Unused - but note that it's a union
 300 *
 301 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
 302 *    NLA_BINARY           Validation function called for the attribute.
 303 *    All other            Unused - but note that it's a union
 304 *
 305 * Example:
 306 *
 307 * static const u32 myvalidflags = 0xff231023;
 308 *
 309 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
 310 * 	[ATTR_FOO] = { .type = NLA_U16 },
 311 *	[ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
 312 *	[ATTR_BAZ] = { .type = NLA_EXACT_LEN, .len = sizeof(struct mystruct) },
 313 *	[ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
 314 * };
 315 */
 316struct nla_policy {
 317	u8		type;
 318	u8		validation_type;
 319	u16		len;
 320	union {
 321		const u32 bitfield32_valid;
 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_MIN_LEN to get the
 339		 * previous pure { .len = xyz } behaviour. The advantage of this
 340		 * is that types not specified in the policy will be rejected.
 341		 *
 342		 * For completely new families it should be set to 1 so that the
 343		 * validation is enforced for all attributes. For existing ones
 344		 * it should be set at least when new attributes are added to
 345		 * the enum used by the policy, and be set to the new value that
 346		 * was added to enforce strict validation from thereon.
 347		 */
 348		u16 strict_start_type;
 349	};
 350};
 351
 352#define NLA_POLICY_EXACT_LEN(_len)	{ .type = NLA_EXACT_LEN, .len = _len }
 353#define NLA_POLICY_EXACT_LEN_WARN(_len) \
 354	{ .type = NLA_EXACT_LEN, .len = _len, \
 355	  .validation_type = NLA_VALIDATE_WARN_TOO_LONG, }
 356#define NLA_POLICY_MIN_LEN(_len)	{ .type = NLA_MIN_LEN, .len = _len }
 357
 358#define NLA_POLICY_ETH_ADDR		NLA_POLICY_EXACT_LEN(ETH_ALEN)
 359#define NLA_POLICY_ETH_ADDR_COMPAT	NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
 360
 361#define _NLA_POLICY_NESTED(maxattr, policy) \
 362	{ .type = NLA_NESTED, .nested_policy = policy, .len = maxattr }
 363#define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \
 364	{ .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr }
 365#define NLA_POLICY_NESTED(policy) \
 366	_NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy)
 367#define NLA_POLICY_NESTED_ARRAY(policy) \
 368	_NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy)
 369#define NLA_POLICY_BITFIELD32(valid) \
 370	{ .type = NLA_BITFIELD32, .bitfield32_valid = valid }
 371
 372#define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
 373#define NLA_ENSURE_UINT_TYPE(tp)			\
 374	(__NLA_ENSURE(tp == NLA_U8 || tp == NLA_U16 ||	\
 375		      tp == NLA_U32 || tp == NLA_U64 ||	\
 376		      tp == NLA_MSECS) + tp)
 377#define NLA_ENSURE_SINT_TYPE(tp)			\
 378	(__NLA_ENSURE(tp == NLA_S8 || tp == NLA_S16  ||	\
 379		      tp == NLA_S32 || tp == NLA_S64) + tp)
 380#define NLA_ENSURE_INT_TYPE(tp)				\
 381	(__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 ||	\
 382		      tp == NLA_S16 || tp == NLA_U16 ||	\
 383		      tp == NLA_S32 || tp == NLA_U32 ||	\
 384		      tp == NLA_S64 || tp == NLA_U64 ||	\
 385		      tp == NLA_MSECS) + 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_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_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_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_TYPE(tp),		\
 419	.validation_type = NLA_VALIDATE_MAX,		\
 420	.max = _max,					\
 421}
 422
 423#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) {		\
 424	.type = NLA_ENSURE_NO_VALIDATION_PTR(tp),	\
 425	.validation_type = NLA_VALIDATE_FUNCTION,	\
 426	.validate = fn,					\
 427	.len = __VA_ARGS__ + 0,				\
 428}
 429
 430/**
 431 * struct nl_info - netlink source information
 432 * @nlh: Netlink message header of original request
 433 * @nl_net: Network namespace
 434 * @portid: Netlink PORTID of requesting application
 435 * @skip_notify: Skip netlink notifications to user space
 436 * @skip_notify_kernel: Skip selected in-kernel notifications
 437 */
 438struct nl_info {
 439	struct nlmsghdr		*nlh;
 440	struct net		*nl_net;
 441	u32			portid;
 442	u8			skip_notify:1,
 443				skip_notify_kernel:1;
 444};
 445
 446/**
 447 * enum netlink_validation - netlink message/attribute validation levels
 448 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
 449 *	extra data at the end of the message, attributes being longer than
 450 *	they should be, or unknown attributes being present.
 451 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
 452 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
 453 *	this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
 454 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
 455 *	This can safely be set by the kernel when the given policy has no
 456 *	NLA_UNSPEC anymore, and can thus be used to ensure policy entries
 457 *	are enforced going forward.
 458 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
 459 *	U8, U16, U32 must have exact size, etc.)
 460 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
 461 *	and unset for other policies.
 462 */
 463enum netlink_validation {
 464	NL_VALIDATE_LIBERAL = 0,
 465	NL_VALIDATE_TRAILING = BIT(0),
 466	NL_VALIDATE_MAXTYPE = BIT(1),
 467	NL_VALIDATE_UNSPEC = BIT(2),
 468	NL_VALIDATE_STRICT_ATTRS = BIT(3),
 469	NL_VALIDATE_NESTED = BIT(4),
 470};
 471
 472#define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
 473				       NL_VALIDATE_MAXTYPE)
 474#define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
 475			    NL_VALIDATE_MAXTYPE |\
 476			    NL_VALIDATE_UNSPEC |\
 477			    NL_VALIDATE_STRICT_ATTRS |\
 478			    NL_VALIDATE_NESTED)
 479
 480int netlink_rcv_skb(struct sk_buff *skb,
 481		    int (*cb)(struct sk_buff *, struct nlmsghdr *,
 482			      struct netlink_ext_ack *));
 483int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
 484		 unsigned int group, int report, gfp_t flags);
 485
 486int __nla_validate(const struct nlattr *head, int len, int maxtype,
 487		   const struct nla_policy *policy, unsigned int validate,
 488		   struct netlink_ext_ack *extack);
 489int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
 490		int len, const struct nla_policy *policy, unsigned int validate,
 491		struct netlink_ext_ack *extack);
 492int nla_policy_len(const struct nla_policy *, int);
 493struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
 494size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
 495char *nla_strdup(const struct nlattr *nla, gfp_t flags);
 496int nla_memcpy(void *dest, const struct nlattr *src, int count);
 497int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
 498int nla_strcmp(const struct nlattr *nla, const char *str);
 499struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
 500struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
 501				   int attrlen, int padattr);
 502void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
 503struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
 504struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
 505				 int attrlen, int padattr);
 506void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
 507void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
 508	       const void *data);
 509void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
 510		     const void *data, int padattr);
 511void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
 512int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
 513int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
 514		  const void *data, int padattr);
 515int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
 516int nla_append(struct sk_buff *skb, int attrlen, const void *data);
 517
 518/**************************************************************************
 519 * Netlink Messages
 520 **************************************************************************/
 521
 522/**
 523 * nlmsg_msg_size - length of netlink message not including padding
 524 * @payload: length of message payload
 525 */
 526static inline int nlmsg_msg_size(int payload)
 527{
 528	return NLMSG_HDRLEN + payload;
 529}
 530
 531/**
 532 * nlmsg_total_size - length of netlink message including padding
 533 * @payload: length of message payload
 534 */
 535static inline int nlmsg_total_size(int payload)
 536{
 537	return NLMSG_ALIGN(nlmsg_msg_size(payload));
 538}
 539
 540/**
 541 * nlmsg_padlen - length of padding at the message's tail
 542 * @payload: length of message payload
 543 */
 544static inline int nlmsg_padlen(int payload)
 545{
 546	return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
 547}
 548
 549/**
 550 * nlmsg_data - head of message payload
 551 * @nlh: netlink message header
 552 */
 553static inline void *nlmsg_data(const struct nlmsghdr *nlh)
 554{
 555	return (unsigned char *) nlh + NLMSG_HDRLEN;
 556}
 557
 558/**
 559 * nlmsg_len - length of message payload
 560 * @nlh: netlink message header
 561 */
 562static inline int nlmsg_len(const struct nlmsghdr *nlh)
 563{
 564	return nlh->nlmsg_len - NLMSG_HDRLEN;
 565}
 566
 567/**
 568 * nlmsg_attrdata - head of attributes data
 569 * @nlh: netlink message header
 570 * @hdrlen: length of family specific header
 571 */
 572static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
 573					    int hdrlen)
 574{
 575	unsigned char *data = nlmsg_data(nlh);
 576	return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
 577}
 578
 579/**
 580 * nlmsg_attrlen - length of attributes data
 581 * @nlh: netlink message header
 582 * @hdrlen: length of family specific header
 583 */
 584static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
 585{
 586	return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
 587}
 588
 589/**
 590 * nlmsg_ok - check if the netlink message fits into the remaining bytes
 591 * @nlh: netlink message header
 592 * @remaining: number of bytes remaining in message stream
 593 */
 594static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
 595{
 596	return (remaining >= (int) sizeof(struct nlmsghdr) &&
 597		nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
 598		nlh->nlmsg_len <= remaining);
 599}
 600
 601/**
 602 * nlmsg_next - next netlink message in message stream
 603 * @nlh: netlink message header
 604 * @remaining: number of bytes remaining in message stream
 605 *
 606 * Returns the next netlink message in the message stream and
 607 * decrements remaining by the size of the current message.
 608 */
 609static inline struct nlmsghdr *
 610nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
 611{
 612	int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
 613
 614	*remaining -= totlen;
 615
 616	return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
 617}
 618
 619/**
 620 * nla_parse - Parse a stream of attributes into a tb buffer
 621 * @tb: destination array with maxtype+1 elements
 622 * @maxtype: maximum attribute type to be expected
 623 * @head: head of attribute stream
 624 * @len: length of attribute stream
 625 * @policy: validation policy
 626 * @extack: extended ACK pointer
 627 *
 628 * Parses a stream of attributes and stores a pointer to each attribute in
 629 * the tb array accessible via the attribute type. Attributes with a type
 630 * exceeding maxtype will be rejected, policy must be specified, attributes
 631 * will be validated in the strictest way possible.
 632 *
 633 * Returns 0 on success or a negative error code.
 634 */
 635static inline int nla_parse(struct nlattr **tb, int maxtype,
 636			    const struct nlattr *head, int len,
 637			    const struct nla_policy *policy,
 638			    struct netlink_ext_ack *extack)
 639{
 640	return __nla_parse(tb, maxtype, head, len, policy,
 641			   NL_VALIDATE_STRICT, extack);
 642}
 643
 644/**
 645 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer
 646 * @tb: destination array with maxtype+1 elements
 647 * @maxtype: maximum attribute type to be expected
 648 * @head: head of attribute stream
 649 * @len: length of attribute stream
 650 * @policy: validation policy
 651 * @extack: extended ACK pointer
 652 *
 653 * Parses a stream of attributes and stores a pointer to each attribute in
 654 * the tb array accessible via the attribute type. Attributes with a type
 655 * exceeding maxtype will be ignored and attributes from the policy are not
 656 * always strictly validated (only for new attributes).
 657 *
 658 * Returns 0 on success or a negative error code.
 659 */
 660static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
 661				       const struct nlattr *head, int len,
 662				       const struct nla_policy *policy,
 663				       struct netlink_ext_ack *extack)
 664{
 665	return __nla_parse(tb, maxtype, head, len, policy,
 666			   NL_VALIDATE_LIBERAL, extack);
 667}
 668
 669/**
 670 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer
 671 * @tb: destination array with maxtype+1 elements
 672 * @maxtype: maximum attribute type to be expected
 673 * @head: head of attribute stream
 674 * @len: length of attribute stream
 675 * @policy: validation policy
 676 * @extack: extended ACK pointer
 677 *
 678 * Parses a stream of attributes and stores a pointer to each attribute in
 679 * the tb array accessible via the attribute type. Attributes with a type
 680 * exceeding maxtype will be rejected as well as trailing data, but the
 681 * policy is not completely strictly validated (only for new attributes).
 682 *
 683 * Returns 0 on success or a negative error code.
 684 */
 685static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
 686					      const struct nlattr *head,
 687					      int len,
 688					      const struct nla_policy *policy,
 689					      struct netlink_ext_ack *extack)
 690{
 691	return __nla_parse(tb, maxtype, head, len, policy,
 692			   NL_VALIDATE_DEPRECATED_STRICT, extack);
 693}
 694
 695/**
 696 * __nlmsg_parse - parse attributes of a netlink message
 697 * @nlh: netlink message header
 698 * @hdrlen: length of family specific header
 699 * @tb: destination array with maxtype+1 elements
 700 * @maxtype: maximum attribute type to be expected
 701 * @policy: validation policy
 702 * @validate: validation strictness
 703 * @extack: extended ACK report struct
 704 *
 705 * See nla_parse()
 706 */
 707static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
 708				struct nlattr *tb[], int maxtype,
 709				const struct nla_policy *policy,
 710				unsigned int validate,
 711				struct netlink_ext_ack *extack)
 712{
 713	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
 714		NL_SET_ERR_MSG(extack, "Invalid header length");
 715		return -EINVAL;
 716	}
 717
 718	return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
 719			   nlmsg_attrlen(nlh, hdrlen), policy, validate,
 720			   extack);
 721}
 722
 723/**
 724 * nlmsg_parse - parse attributes of a netlink message
 725 * @nlh: netlink message header
 726 * @hdrlen: length of family specific header
 727 * @tb: destination array with maxtype+1 elements
 728 * @maxtype: maximum attribute type to be expected
 729 * @extack: extended ACK report struct
 730 *
 731 * See nla_parse()
 732 */
 733static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
 734			      struct nlattr *tb[], int maxtype,
 735			      const struct nla_policy *policy,
 736			      struct netlink_ext_ack *extack)
 737{
 738	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
 739			     NL_VALIDATE_STRICT, extack);
 740}
 741
 742/**
 743 * nlmsg_parse_deprecated - parse attributes of a netlink message
 744 * @nlh: netlink message header
 745 * @hdrlen: length of family specific header
 746 * @tb: destination array with maxtype+1 elements
 747 * @maxtype: maximum attribute type to be expected
 748 * @extack: extended ACK report struct
 749 *
 750 * See nla_parse_deprecated()
 751 */
 752static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
 753					 struct nlattr *tb[], int maxtype,
 754					 const struct nla_policy *policy,
 755					 struct netlink_ext_ack *extack)
 756{
 757	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
 758			     NL_VALIDATE_LIBERAL, extack);
 759}
 760
 761/**
 762 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
 763 * @nlh: netlink message header
 764 * @hdrlen: length of family specific header
 765 * @tb: destination array with maxtype+1 elements
 766 * @maxtype: maximum attribute type to be expected
 767 * @extack: extended ACK report struct
 768 *
 769 * See nla_parse_deprecated_strict()
 770 */
 771static inline int
 772nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
 773			      struct nlattr *tb[], int maxtype,
 774			      const struct nla_policy *policy,
 775			      struct netlink_ext_ack *extack)
 776{
 777	return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
 778			     NL_VALIDATE_DEPRECATED_STRICT, extack);
 779}
 780
 781/**
 782 * nlmsg_find_attr - find a specific attribute in a netlink message
 783 * @nlh: netlink message header
 784 * @hdrlen: length of familiy specific header
 785 * @attrtype: type of attribute to look for
 786 *
 787 * Returns the first attribute which matches the specified type.
 788 */
 789static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
 790					     int hdrlen, int attrtype)
 791{
 792	return nla_find(nlmsg_attrdata(nlh, hdrlen),
 793			nlmsg_attrlen(nlh, hdrlen), attrtype);
 794}
 795
 796/**
 797 * nla_validate_deprecated - Validate a stream of attributes
 798 * @head: head of attribute stream
 799 * @len: length of attribute stream
 800 * @maxtype: maximum attribute type to be expected
 801 * @policy: validation policy
 802 * @validate: validation strictness
 803 * @extack: extended ACK report struct
 804 *
 805 * Validates all attributes in the specified attribute stream against the
 806 * specified policy. Validation is done in liberal mode.
 807 * See documenation of struct nla_policy for more details.
 808 *
 809 * Returns 0 on success or a negative error code.
 810 */
 811static inline int nla_validate_deprecated(const struct nlattr *head, int len,
 812					  int maxtype,
 813					  const struct nla_policy *policy,
 814					  struct netlink_ext_ack *extack)
 815{
 816	return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
 817			      extack);
 818}
 819
 820/**
 821 * nla_validate - Validate a stream of attributes
 822 * @head: head of attribute stream
 823 * @len: length of attribute stream
 824 * @maxtype: maximum attribute type to be expected
 825 * @policy: validation policy
 826 * @extack: extended ACK report struct
 827 *
 828 * Validates all attributes in the specified attribute stream against the
 829 * specified policy. Validation is done in strict mode.
 830 * See documenation of struct nla_policy for more details.
 831 *
 832 * Returns 0 on success or a negative error code.
 833 */
 834static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
 835			       const struct nla_policy *policy,
 836			       struct netlink_ext_ack *extack)
 837{
 838	return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
 839			      extack);
 840}
 841
 842/**
 843 * nlmsg_validate_deprecated - validate a netlink message including attributes
 844 * @nlh: netlinket message header
 845 * @hdrlen: length of familiy specific header
 846 * @maxtype: maximum attribute type to be expected
 847 * @policy: validation policy
 848 * @extack: extended ACK report struct
 849 */
 850static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
 851					    int hdrlen, int maxtype,
 852					    const struct nla_policy *policy,
 853					    struct netlink_ext_ack *extack)
 854{
 855	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
 856		return -EINVAL;
 857
 858	return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
 859			      nlmsg_attrlen(nlh, hdrlen), maxtype,
 860			      policy, NL_VALIDATE_LIBERAL, extack);
 861}
 862
 863
 864
 865/**
 866 * nlmsg_report - need to report back to application?
 867 * @nlh: netlink message header
 868 *
 869 * Returns 1 if a report back to the application is requested.
 870 */
 871static inline int nlmsg_report(const struct nlmsghdr *nlh)
 872{
 873	return !!(nlh->nlmsg_flags & NLM_F_ECHO);
 874}
 875
 876/**
 877 * nlmsg_for_each_attr - iterate over a stream of attributes
 878 * @pos: loop counter, set to current attribute
 879 * @nlh: netlink message header
 880 * @hdrlen: length of familiy specific header
 881 * @rem: initialized to len, holds bytes currently remaining in stream
 882 */
 883#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
 884	nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
 885			  nlmsg_attrlen(nlh, hdrlen), rem)
 886
 887/**
 888 * nlmsg_put - Add a new netlink message to an skb
 889 * @skb: socket buffer to store message in
 890 * @portid: netlink PORTID of requesting application
 891 * @seq: sequence number of message
 892 * @type: message type
 893 * @payload: length of message payload
 894 * @flags: message flags
 895 *
 896 * Returns NULL if the tailroom of the skb is insufficient to store
 897 * the message header and payload.
 898 */
 899static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
 900					 int type, int payload, int flags)
 901{
 902	if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
 903		return NULL;
 904
 905	return __nlmsg_put(skb, portid, seq, type, payload, flags);
 906}
 907
 908/**
 909 * nlmsg_put_answer - Add a new callback based netlink message to an skb
 910 * @skb: socket buffer to store message in
 911 * @cb: netlink callback
 912 * @type: message type
 913 * @payload: length of message payload
 914 * @flags: message flags
 915 *
 916 * Returns NULL if the tailroom of the skb is insufficient to store
 917 * the message header and payload.
 918 */
 919static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
 920						struct netlink_callback *cb,
 921						int type, int payload,
 922						int flags)
 923{
 924	return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 925			 type, payload, flags);
 926}
 927
 928/**
 929 * nlmsg_new - Allocate a new netlink message
 930 * @payload: size of the message payload
 931 * @flags: the type of memory to allocate.
 932 *
 933 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
 934 * and a good default is needed.
 935 */
 936static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
 937{
 938	return alloc_skb(nlmsg_total_size(payload), flags);
 939}
 940
 941/**
 942 * nlmsg_end - Finalize a netlink message
 943 * @skb: socket buffer the message is stored in
 944 * @nlh: netlink message header
 945 *
 946 * Corrects the netlink message header to include the appeneded
 947 * attributes. Only necessary if attributes have been added to
 948 * the message.
 949 */
 950static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
 951{
 952	nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
 953}
 954
 955/**
 956 * nlmsg_get_pos - return current position in netlink message
 957 * @skb: socket buffer the message is stored in
 958 *
 959 * Returns a pointer to the current tail of the message.
 960 */
 961static inline void *nlmsg_get_pos(struct sk_buff *skb)
 962{
 963	return skb_tail_pointer(skb);
 964}
 965
 966/**
 967 * nlmsg_trim - Trim message to a mark
 968 * @skb: socket buffer the message is stored in
 969 * @mark: mark to trim to
 970 *
 971 * Trims the message to the provided mark.
 972 */
 973static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
 974{
 975	if (mark) {
 976		WARN_ON((unsigned char *) mark < skb->data);
 977		skb_trim(skb, (unsigned char *) mark - skb->data);
 978	}
 979}
 980
 981/**
 982 * nlmsg_cancel - Cancel construction of a netlink message
 983 * @skb: socket buffer the message is stored in
 984 * @nlh: netlink message header
 985 *
 986 * Removes the complete netlink message including all
 987 * attributes from the socket buffer again.
 988 */
 989static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
 990{
 991	nlmsg_trim(skb, nlh);
 992}
 993
 994/**
 995 * nlmsg_free - free a netlink message
 996 * @skb: socket buffer of netlink message
 997 */
 998static inline void nlmsg_free(struct sk_buff *skb)
 999{
1000	kfree_skb(skb);
1001}
1002
1003/**
1004 * nlmsg_multicast - multicast a netlink message
1005 * @sk: netlink socket to spread messages to
1006 * @skb: netlink message as socket buffer
1007 * @portid: own netlink portid to avoid sending to yourself
1008 * @group: multicast group id
1009 * @flags: allocation flags
1010 */
1011static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
1012				  u32 portid, unsigned int group, gfp_t flags)
1013{
1014	int err;
1015
1016	NETLINK_CB(skb).dst_group = group;
1017
1018	err = netlink_broadcast(sk, skb, portid, group, flags);
1019	if (err > 0)
1020		err = 0;
1021
1022	return err;
1023}
1024
1025/**
1026 * nlmsg_unicast - unicast a netlink message
1027 * @sk: netlink socket to spread message to
1028 * @skb: netlink message as socket buffer
1029 * @portid: netlink portid of the destination socket
1030 */
1031static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
1032{
1033	int err;
1034
1035	err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
1036	if (err > 0)
1037		err = 0;
1038
1039	return err;
1040}
1041
1042/**
1043 * nlmsg_for_each_msg - iterate over a stream of messages
1044 * @pos: loop counter, set to current message
1045 * @head: head of message stream
1046 * @len: length of message stream
1047 * @rem: initialized to len, holds bytes currently remaining in stream
1048 */
1049#define nlmsg_for_each_msg(pos, head, len, rem) \
1050	for (pos = head, rem = len; \
1051	     nlmsg_ok(pos, rem); \
1052	     pos = nlmsg_next(pos, &(rem)))
1053
1054/**
1055 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
1056 * @cb: netlink callback structure that stores the sequence number
1057 * @nlh: netlink message header to write the flag to
1058 *
1059 * This function checks if the sequence (generation) number changed during dump
1060 * and if it did, advertises it in the netlink message header.
1061 *
1062 * The correct way to use it is to set cb->seq to the generation counter when
1063 * all locks for dumping have been acquired, and then call this function for
1064 * each message that is generated.
1065 *
1066 * Note that due to initialisation concerns, 0 is an invalid sequence number
1067 * and must not be used by code that uses this functionality.
1068 */
1069static inline void
1070nl_dump_check_consistent(struct netlink_callback *cb,
1071			 struct nlmsghdr *nlh)
1072{
1073	if (cb->prev_seq && cb->seq != cb->prev_seq)
1074		nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
1075	cb->prev_seq = cb->seq;
1076}
1077
1078/**************************************************************************
1079 * Netlink Attributes
1080 **************************************************************************/
1081
1082/**
1083 * nla_attr_size - length of attribute not including padding
1084 * @payload: length of payload
1085 */
1086static inline int nla_attr_size(int payload)
1087{
1088	return NLA_HDRLEN + payload;
1089}
1090
1091/**
1092 * nla_total_size - total length of attribute including padding
1093 * @payload: length of payload
1094 */
1095static inline int nla_total_size(int payload)
1096{
1097	return NLA_ALIGN(nla_attr_size(payload));
1098}
1099
1100/**
1101 * nla_padlen - length of padding at the tail of attribute
1102 * @payload: length of payload
1103 */
1104static inline int nla_padlen(int payload)
1105{
1106	return nla_total_size(payload) - nla_attr_size(payload);
1107}
1108
1109/**
1110 * nla_type - attribute type
1111 * @nla: netlink attribute
1112 */
1113static inline int nla_type(const struct nlattr *nla)
1114{
1115	return nla->nla_type & NLA_TYPE_MASK;
1116}
1117
1118/**
1119 * nla_data - head of payload
1120 * @nla: netlink attribute
1121 */
1122static inline void *nla_data(const struct nlattr *nla)
1123{
1124	return (char *) nla + NLA_HDRLEN;
1125}
1126
1127/**
1128 * nla_len - length of payload
1129 * @nla: netlink attribute
1130 */
1131static inline int nla_len(const struct nlattr *nla)
1132{
1133	return nla->nla_len - NLA_HDRLEN;
1134}
1135
1136/**
1137 * nla_ok - check if the netlink attribute fits into the remaining bytes
1138 * @nla: netlink attribute
1139 * @remaining: number of bytes remaining in attribute stream
1140 */
1141static inline int nla_ok(const struct nlattr *nla, int remaining)
1142{
1143	return remaining >= (int) sizeof(*nla) &&
1144	       nla->nla_len >= sizeof(*nla) &&
1145	       nla->nla_len <= remaining;
1146}
1147
1148/**
1149 * nla_next - next netlink attribute in attribute stream
1150 * @nla: netlink attribute
1151 * @remaining: number of bytes remaining in attribute stream
1152 *
1153 * Returns the next netlink attribute in the attribute stream and
1154 * decrements remaining by the size of the current attribute.
1155 */
1156static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
1157{
1158	unsigned int totlen = NLA_ALIGN(nla->nla_len);
1159
1160	*remaining -= totlen;
1161	return (struct nlattr *) ((char *) nla + totlen);
1162}
1163
1164/**
1165 * nla_find_nested - find attribute in a set of nested attributes
1166 * @nla: attribute containing the nested attributes
1167 * @attrtype: type of attribute to look for
1168 *
1169 * Returns the first attribute which matches the specified type.
1170 */
1171static inline struct nlattr *
1172nla_find_nested(const struct nlattr *nla, int attrtype)
1173{
1174	return nla_find(nla_data(nla), nla_len(nla), attrtype);
1175}
1176
1177/**
1178 * nla_parse_nested - parse nested attributes
1179 * @tb: destination array with maxtype+1 elements
1180 * @maxtype: maximum attribute type to be expected
1181 * @nla: attribute containing the nested attributes
1182 * @policy: validation policy
1183 * @extack: extended ACK report struct
1184 *
1185 * See nla_parse()
1186 */
1187static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
1188				   const struct nlattr *nla,
1189				   const struct nla_policy *policy,
1190				   struct netlink_ext_ack *extack)
1191{
1192	if (!(nla->nla_type & NLA_F_NESTED)) {
1193		NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
1194		return -EINVAL;
1195	}
1196
1197	return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1198			   NL_VALIDATE_STRICT, extack);
1199}
1200
1201/**
1202 * nla_parse_nested_deprecated - parse nested attributes
1203 * @tb: destination array with maxtype+1 elements
1204 * @maxtype: maximum attribute type to be expected
1205 * @nla: attribute containing the nested attributes
1206 * @policy: validation policy
1207 * @extack: extended ACK report struct
1208 *
1209 * See nla_parse_deprecated()
1210 */
1211static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
1212					      const struct nlattr *nla,
1213					      const struct nla_policy *policy,
1214					      struct netlink_ext_ack *extack)
1215{
1216	return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
1217			   NL_VALIDATE_LIBERAL, extack);
1218}
1219
1220/**
1221 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
1222 * @skb: socket buffer to add attribute to
1223 * @attrtype: attribute type
1224 * @value: numeric value
1225 */
1226static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
1227{
1228	/* temporary variables to work around GCC PR81715 with asan-stack=1 */
1229	u8 tmp = value;
1230
1231	return nla_put(skb, attrtype, sizeof(u8), &tmp);
1232}
1233
1234/**
1235 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
1236 * @skb: socket buffer to add attribute to
1237 * @attrtype: attribute type
1238 * @value: numeric value
1239 */
1240static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
1241{
1242	u16 tmp = value;
1243
1244	return nla_put(skb, attrtype, sizeof(u16), &tmp);
1245}
1246
1247/**
1248 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
1249 * @skb: socket buffer to add attribute to
1250 * @attrtype: attribute type
1251 * @value: numeric value
1252 */
1253static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
1254{
1255	__be16 tmp = value;
1256
1257	return nla_put(skb, attrtype, sizeof(__be16), &tmp);
1258}
1259
1260/**
1261 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
1262 * @skb: socket buffer to add attribute to
1263 * @attrtype: attribute type
1264 * @value: numeric value
1265 */
1266static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
1267{
1268	__be16 tmp = value;
1269
1270	return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1271}
1272
1273/**
1274 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
1275 * @skb: socket buffer to add attribute to
1276 * @attrtype: attribute type
1277 * @value: numeric value
1278 */
1279static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
1280{
1281	__le16 tmp = value;
1282
1283	return nla_put(skb, attrtype, sizeof(__le16), &tmp);
1284}
1285
1286/**
1287 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
1288 * @skb: socket buffer to add attribute to
1289 * @attrtype: attribute type
1290 * @value: numeric value
1291 */
1292static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
1293{
1294	u32 tmp = value;
1295
1296	return nla_put(skb, attrtype, sizeof(u32), &tmp);
1297}
1298
1299/**
1300 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
1301 * @skb: socket buffer to add attribute to
1302 * @attrtype: attribute type
1303 * @value: numeric value
1304 */
1305static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
1306{
1307	__be32 tmp = value;
1308
1309	return nla_put(skb, attrtype, sizeof(__be32), &tmp);
1310}
1311
1312/**
1313 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
1314 * @skb: socket buffer to add attribute to
1315 * @attrtype: attribute type
1316 * @value: numeric value
1317 */
1318static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
1319{
1320	__be32 tmp = value;
1321
1322	return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp);
1323}
1324
1325/**
1326 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
1327 * @skb: socket buffer to add attribute to
1328 * @attrtype: attribute type
1329 * @value: numeric value
1330 */
1331static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
1332{
1333	__le32 tmp = value;
1334
1335	return nla_put(skb, attrtype, sizeof(__le32), &tmp);
1336}
1337
1338/**
1339 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it
1340 * @skb: socket buffer to add attribute to
1341 * @attrtype: attribute type
1342 * @value: numeric value
1343 * @padattr: attribute type for the padding
1344 */
1345static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype,
1346				    u64 value, int padattr)
1347{
1348	u64 tmp = value;
1349
1350	return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1351}
1352
1353/**
1354 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer 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_be64(struct sk_buff *skb, int attrtype, __be64 value,
1361			       int padattr)
1362{
1363	__be64 tmp = value;
1364
1365	return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr);
1366}
1367
1368/**
1369 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb 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_net64(struct sk_buff *skb, int attrtype, __be64 value,
1376				int padattr)
1377{
1378	__be64 tmp = value;
1379
1380	return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp,
1381			    padattr);
1382}
1383
1384/**
1385 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it
1386 * @skb: socket buffer to add attribute to
1387 * @attrtype: attribute type
1388 * @value: numeric value
1389 * @padattr: attribute type for the padding
1390 */
1391static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value,
1392			       int padattr)
1393{
1394	__le64 tmp = value;
1395
1396	return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr);
1397}
1398
1399/**
1400 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
1401 * @skb: socket buffer to add attribute to
1402 * @attrtype: attribute type
1403 * @value: numeric value
1404 */
1405static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
1406{
1407	s8 tmp = value;
1408
1409	return nla_put(skb, attrtype, sizeof(s8), &tmp);
1410}
1411
1412/**
1413 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
1414 * @skb: socket buffer to add attribute to
1415 * @attrtype: attribute type
1416 * @value: numeric value
1417 */
1418static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
1419{
1420	s16 tmp = value;
1421
1422	return nla_put(skb, attrtype, sizeof(s16), &tmp);
1423}
1424
1425/**
1426 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
1427 * @skb: socket buffer to add attribute to
1428 * @attrtype: attribute type
1429 * @value: numeric value
1430 */
1431static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
1432{
1433	s32 tmp = value;
1434
1435	return nla_put(skb, attrtype, sizeof(s32), &tmp);
1436}
1437
1438/**
1439 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it
1440 * @skb: socket buffer to add attribute to
1441 * @attrtype: attribute type
1442 * @value: numeric value
1443 * @padattr: attribute type for the padding
1444 */
1445static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
1446			      int padattr)
1447{
1448	s64 tmp = value;
1449
1450	return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr);
1451}
1452
1453/**
1454 * nla_put_string - Add a string netlink attribute to a socket buffer
1455 * @skb: socket buffer to add attribute to
1456 * @attrtype: attribute type
1457 * @str: NUL terminated string
1458 */
1459static inline int nla_put_string(struct sk_buff *skb, int attrtype,
1460				 const char *str)
1461{
1462	return nla_put(skb, attrtype, strlen(str) + 1, str);
1463}
1464
1465/**
1466 * nla_put_flag - Add a flag netlink attribute to a socket buffer
1467 * @skb: socket buffer to add attribute to
1468 * @attrtype: attribute type
1469 */
1470static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
1471{
1472	return nla_put(skb, attrtype, 0, NULL);
1473}
1474
1475/**
1476 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it
1477 * @skb: socket buffer to add attribute to
1478 * @attrtype: attribute type
1479 * @njiffies: number of jiffies to convert to msecs
1480 * @padattr: attribute type for the padding
1481 */
1482static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
1483				unsigned long njiffies, int padattr)
1484{
1485	u64 tmp = jiffies_to_msecs(njiffies);
1486
1487	return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr);
1488}
1489
1490/**
1491 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
1492 * buffer
1493 * @skb: socket buffer to add attribute to
1494 * @attrtype: attribute type
1495 * @addr: IPv4 address
1496 */
1497static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
1498				  __be32 addr)
1499{
1500	__be32 tmp = addr;
1501
1502	return nla_put_be32(skb, attrtype, tmp);
1503}
1504
1505/**
1506 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
1507 * buffer
1508 * @skb: socket buffer to add attribute to
1509 * @attrtype: attribute type
1510 * @addr: IPv6 address
1511 */
1512static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
1513				   const struct in6_addr *addr)
1514{
1515	return nla_put(skb, attrtype, sizeof(*addr), addr);
1516}
1517
1518/**
1519 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer
1520 * @skb: socket buffer to add attribute to
1521 * @attrtype: attribute type
1522 * @value: value carrying bits
1523 * @selector: selector of valid bits
1524 */
1525static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype,
1526				     __u32 value, __u32 selector)
1527{
1528	struct nla_bitfield32 tmp = { value, selector, };
1529
1530	return nla_put(skb, attrtype, sizeof(tmp), &tmp);
1531}
1532
1533/**
1534 * nla_get_u32 - return payload of u32 attribute
1535 * @nla: u32 netlink attribute
1536 */
1537static inline u32 nla_get_u32(const struct nlattr *nla)
1538{
1539	return *(u32 *) nla_data(nla);
1540}
1541
1542/**
1543 * nla_get_be32 - return payload of __be32 attribute
1544 * @nla: __be32 netlink attribute
1545 */
1546static inline __be32 nla_get_be32(const struct nlattr *nla)
1547{
1548	return *(__be32 *) nla_data(nla);
1549}
1550
1551/**
1552 * nla_get_le32 - return payload of __le32 attribute
1553 * @nla: __le32 netlink attribute
1554 */
1555static inline __le32 nla_get_le32(const struct nlattr *nla)
1556{
1557	return *(__le32 *) nla_data(nla);
1558}
1559
1560/**
1561 * nla_get_u16 - return payload of u16 attribute
1562 * @nla: u16 netlink attribute
1563 */
1564static inline u16 nla_get_u16(const struct nlattr *nla)
1565{
1566	return *(u16 *) nla_data(nla);
1567}
1568
1569/**
1570 * nla_get_be16 - return payload of __be16 attribute
1571 * @nla: __be16 netlink attribute
1572 */
1573static inline __be16 nla_get_be16(const struct nlattr *nla)
1574{
1575	return *(__be16 *) nla_data(nla);
1576}
1577
1578/**
1579 * nla_get_le16 - return payload of __le16 attribute
1580 * @nla: __le16 netlink attribute
1581 */
1582static inline __le16 nla_get_le16(const struct nlattr *nla)
1583{
1584	return *(__le16 *) nla_data(nla);
1585}
1586
1587/**
1588 * nla_get_u8 - return payload of u8 attribute
1589 * @nla: u8 netlink attribute
1590 */
1591static inline u8 nla_get_u8(const struct nlattr *nla)
1592{
1593	return *(u8 *) nla_data(nla);
1594}
1595
1596/**
1597 * nla_get_u64 - return payload of u64 attribute
1598 * @nla: u64 netlink attribute
1599 */
1600static inline u64 nla_get_u64(const struct nlattr *nla)
1601{
1602	u64 tmp;
1603
1604	nla_memcpy(&tmp, nla, sizeof(tmp));
1605
1606	return tmp;
1607}
1608
1609/**
1610 * nla_get_be64 - return payload of __be64 attribute
1611 * @nla: __be64 netlink attribute
1612 */
1613static inline __be64 nla_get_be64(const struct nlattr *nla)
1614{
1615	__be64 tmp;
1616
1617	nla_memcpy(&tmp, nla, sizeof(tmp));
1618
1619	return tmp;
1620}
1621
1622/**
1623 * nla_get_le64 - return payload of __le64 attribute
1624 * @nla: __le64 netlink attribute
1625 */
1626static inline __le64 nla_get_le64(const struct nlattr *nla)
1627{
1628	return *(__le64 *) nla_data(nla);
1629}
1630
1631/**
1632 * nla_get_s32 - return payload of s32 attribute
1633 * @nla: s32 netlink attribute
1634 */
1635static inline s32 nla_get_s32(const struct nlattr *nla)
1636{
1637	return *(s32 *) nla_data(nla);
1638}
1639
1640/**
1641 * nla_get_s16 - return payload of s16 attribute
1642 * @nla: s16 netlink attribute
1643 */
1644static inline s16 nla_get_s16(const struct nlattr *nla)
1645{
1646	return *(s16 *) nla_data(nla);
1647}
1648
1649/**
1650 * nla_get_s8 - return payload of s8 attribute
1651 * @nla: s8 netlink attribute
1652 */
1653static inline s8 nla_get_s8(const struct nlattr *nla)
1654{
1655	return *(s8 *) nla_data(nla);
1656}
1657
1658/**
1659 * nla_get_s64 - return payload of s64 attribute
1660 * @nla: s64 netlink attribute
1661 */
1662static inline s64 nla_get_s64(const struct nlattr *nla)
1663{
1664	s64 tmp;
1665
1666	nla_memcpy(&tmp, nla, sizeof(tmp));
1667
1668	return tmp;
1669}
1670
1671/**
1672 * nla_get_flag - return payload of flag attribute
1673 * @nla: flag netlink attribute
1674 */
1675static inline int nla_get_flag(const struct nlattr *nla)
1676{
1677	return !!nla;
1678}
1679
1680/**
1681 * nla_get_msecs - return payload of msecs attribute
1682 * @nla: msecs netlink attribute
1683 *
1684 * Returns the number of milliseconds in jiffies.
1685 */
1686static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1687{
1688	u64 msecs = nla_get_u64(nla);
1689
1690	return msecs_to_jiffies((unsigned long) msecs);
1691}
1692
1693/**
1694 * nla_get_in_addr - return payload of IPv4 address attribute
1695 * @nla: IPv4 address netlink attribute
1696 */
1697static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1698{
1699	return *(__be32 *) nla_data(nla);
1700}
1701
1702/**
1703 * nla_get_in6_addr - return payload of IPv6 address attribute
1704 * @nla: IPv6 address netlink attribute
1705 */
1706static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1707{
1708	struct in6_addr tmp;
1709
1710	nla_memcpy(&tmp, nla, sizeof(tmp));
1711	return tmp;
1712}
1713
1714/**
1715 * nla_get_bitfield32 - return payload of 32 bitfield attribute
1716 * @nla: nla_bitfield32 attribute
1717 */
1718static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla)
1719{
1720	struct nla_bitfield32 tmp;
1721
1722	nla_memcpy(&tmp, nla, sizeof(tmp));
1723	return tmp;
1724}
1725
1726/**
1727 * nla_memdup - duplicate attribute memory (kmemdup)
1728 * @src: netlink attribute to duplicate from
1729 * @gfp: GFP mask
1730 */
1731static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
1732{
1733	return kmemdup(nla_data(src), nla_len(src), gfp);
1734}
1735
1736/**
1737 * nla_nest_start_noflag - Start a new level of nested attributes
1738 * @skb: socket buffer to add attributes to
1739 * @attrtype: attribute type of container
1740 *
1741 * This function exists for backward compatibility to use in APIs which never
1742 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
1743 * nla_nest_start() which sets the flag.
1744 *
1745 * Returns the container attribute or NULL on error
1746 */
1747static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
1748						   int attrtype)
1749{
1750	struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1751
1752	if (nla_put(skb, attrtype, 0, NULL) < 0)
1753		return NULL;
1754
1755	return start;
1756}
1757
1758/**
1759 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
1760 * @skb: socket buffer to add attributes to
1761 * @attrtype: attribute type of container
1762 *
1763 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
1764 * flag. This is the preferred function to use in new code.
1765 *
1766 * Returns the container attribute or NULL on error
1767 */
1768static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1769{
1770	return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
1771}
1772
1773/**
1774 * nla_nest_end - Finalize nesting of attributes
1775 * @skb: socket buffer the attributes are stored in
1776 * @start: container attribute
1777 *
1778 * Corrects the container attribute header to include the all
1779 * appeneded attributes.
1780 *
1781 * Returns the total data length of the skb.
1782 */
1783static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1784{
1785	start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1786	return skb->len;
1787}
1788
1789/**
1790 * nla_nest_cancel - Cancel nesting of attributes
1791 * @skb: socket buffer the message is stored in
1792 * @start: container attribute
1793 *
1794 * Removes the container attribute and including all nested
1795 * attributes. Returns -EMSGSIZE
1796 */
1797static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1798{
1799	nlmsg_trim(skb, start);
1800}
1801
1802/**
1803 * __nla_validate_nested - Validate a stream of nested attributes
1804 * @start: container attribute
1805 * @maxtype: maximum attribute type to be expected
1806 * @policy: validation policy
1807 * @validate: validation strictness
1808 * @extack: extended ACK report struct
1809 *
1810 * Validates all attributes in the nested attribute stream against the
1811 * specified policy. Attributes with a type exceeding maxtype will be
1812 * ignored. See documenation of struct nla_policy for more details.
1813 *
1814 * Returns 0 on success or a negative error code.
1815 */
1816static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
1817					const struct nla_policy *policy,
1818					unsigned int validate,
1819					struct netlink_ext_ack *extack)
1820{
1821	return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
1822			      validate, extack);
1823}
1824
1825static inline int
1826nla_validate_nested(const struct nlattr *start, int maxtype,
1827		    const struct nla_policy *policy,
1828		    struct netlink_ext_ack *extack)
1829{
1830	return __nla_validate_nested(start, maxtype, policy,
1831				     NL_VALIDATE_STRICT, extack);
1832}
1833
1834static inline int
1835nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
1836			       const struct nla_policy *policy,
1837			       struct netlink_ext_ack *extack)
1838{
1839	return __nla_validate_nested(start, maxtype, policy,
1840				     NL_VALIDATE_LIBERAL, extack);
1841}
1842
1843/**
1844 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1845 * @skb: socket buffer the message is stored in
1846 *
1847 * Return true if padding is needed to align the next attribute (nla_data()) to
1848 * a 64-bit aligned area.
1849 */
1850static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1851{
1852#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1853	/* The nlattr header is 4 bytes in size, that's why we test
1854	 * if the skb->data _is_ aligned.  A NOP attribute, plus
1855	 * nlattr header for next attribute, will make nla_data()
1856	 * 8-byte aligned.
1857	 */
1858	if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1859		return true;
1860#endif
1861	return false;
1862}
1863
1864/**
1865 * nla_align_64bit - 64-bit align the nla_data() of next attribute
1866 * @skb: socket buffer the message is stored in
1867 * @padattr: attribute type for the padding
1868 *
1869 * Conditionally emit a padding netlink attribute in order to make
1870 * the next attribute we emit have a 64-bit aligned nla_data() area.
1871 * This will only be done in architectures which do not have
1872 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1873 *
1874 * Returns zero on success or a negative error code.
1875 */
1876static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1877{
1878	if (nla_need_padding_for_64bit(skb) &&
1879	    !nla_reserve(skb, padattr, 0))
1880		return -EMSGSIZE;
1881
1882	return 0;
1883}
1884
1885/**
1886 * nla_total_size_64bit - total length of attribute including padding
1887 * @payload: length of payload
1888 */
1889static inline int nla_total_size_64bit(int payload)
1890{
1891	return NLA_ALIGN(nla_attr_size(payload))
1892#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1893		+ NLA_ALIGN(nla_attr_size(0))
1894#endif
1895		;
1896}
1897
1898/**
1899 * nla_for_each_attr - iterate over a stream of attributes
1900 * @pos: loop counter, set to current attribute
1901 * @head: head of attribute stream
1902 * @len: length of attribute stream
1903 * @rem: initialized to len, holds bytes currently remaining in stream
1904 */
1905#define nla_for_each_attr(pos, head, len, rem) \
1906	for (pos = head, rem = len; \
1907	     nla_ok(pos, rem); \
1908	     pos = nla_next(pos, &(rem)))
1909
1910/**
1911 * nla_for_each_nested - iterate over nested attributes
1912 * @pos: loop counter, set to current attribute
1913 * @nla: attribute containing the nested attributes
1914 * @rem: initialized to len, holds bytes currently remaining in stream
1915 */
1916#define nla_for_each_nested(pos, nla, rem) \
1917	nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1918
1919/**
1920 * nla_is_last - Test if attribute is last in stream
1921 * @nla: attribute to test
1922 * @rem: bytes remaining in stream
1923 */
1924static inline bool nla_is_last(const struct nlattr *nla, int rem)
1925{
1926	return nla->nla_len == rem;
1927}
1928
1929void nla_get_range_unsigned(const struct nla_policy *pt,
1930			    struct netlink_range_validation *range);
1931void nla_get_range_signed(const struct nla_policy *pt,
1932			  struct netlink_range_validation_signed *range);
1933
1934int netlink_policy_dump_start(const struct nla_policy *policy,
1935			      unsigned int maxtype,
1936			      unsigned long *state);
1937bool netlink_policy_dump_loop(unsigned long state);
1938int netlink_policy_dump_write(struct sk_buff *skb, unsigned long state);
1939void netlink_policy_dump_free(unsigned long state);
1940
1941#endif