1#ifndef __NET_NETLINK_H
   2#define __NET_NETLINK_H
   3
   4#include <linux/types.h>
   5#include <linux/netlink.h>
   6#include <linux/jiffies.h>
   7#include <linux/in6.h>
   8
   9/* ========================================================================
  10 *         Netlink Messages and Attributes Interface (As Seen On TV)
  11 * ------------------------------------------------------------------------
  12 *                          Messages Interface
  13 * ------------------------------------------------------------------------
  14 *
  15 * Message Format:
  16 *    <--- nlmsg_total_size(payload)  --->
  17 *    <-- nlmsg_msg_size(payload) ->
  18 *   +----------+- - -+-------------+- - -+-------- - -
  19 *   | nlmsghdr | Pad |   Payload   | Pad | nlmsghdr
  20 *   +----------+- - -+-------------+- - -+-------- - -
  21 *   nlmsg_data(nlh)---^                   ^
  22 *   nlmsg_next(nlh)-----------------------+
  23 *
  24 * Payload Format:
  25 *    <---------------------- nlmsg_len(nlh) --------------------->
  26 *    <------ hdrlen ------>       <- nlmsg_attrlen(nlh, hdrlen) ->
  27 *   +----------------------+- - -+--------------------------------+
  28 *   |     Family Header    | Pad |           Attributes           |
  29 *   +----------------------+- - -+--------------------------------+
  30 *   nlmsg_attrdata(nlh, hdrlen)---^
  31 *
  32 * Data Structures:
  33 *   struct nlmsghdr			netlink message header
  34 *
  35 * Message Construction:
  36 *   nlmsg_new()			create a new netlink message
  37 *   nlmsg_put()			add a netlink message to an skb
  38 *   nlmsg_put_answer()			callback based nlmsg_put()
  39 *   nlmsg_end()			finalize netlink message
  40 *   nlmsg_get_pos()			return current position in message
  41 *   nlmsg_trim()			trim part of message
  42 *   nlmsg_cancel()			cancel message construction
  43 *   nlmsg_free()			free a netlink message
  44 *
  45 * Message Sending:
  46 *   nlmsg_multicast()			multicast message to several groups
  47 *   nlmsg_unicast()			unicast a message to a single socket
  48 *   nlmsg_notify()			send notification message
  49 *
  50 * Message Length Calculations:
  51 *   nlmsg_msg_size(payload)		length of message w/o padding
  52 *   nlmsg_total_size(payload)		length of message w/ padding
  53 *   nlmsg_padlen(payload)		length of padding at tail
  54 *
  55 * Message Payload Access:
  56 *   nlmsg_data(nlh)			head of message payload
  57 *   nlmsg_len(nlh)			length of message payload
  58 *   nlmsg_attrdata(nlh, hdrlen)	head of attributes data
  59 *   nlmsg_attrlen(nlh, hdrlen)		length of attributes data
  60 *
  61 * Message Parsing:
  62 *   nlmsg_ok(nlh, remaining)		does nlh fit into remaining bytes?
  63 *   nlmsg_next(nlh, remaining)		get next netlink message
  64 *   nlmsg_parse()			parse attributes of a message
  65 *   nlmsg_find_attr()			find an attribute in a message
  66 *   nlmsg_for_each_msg()		loop over all messages
  67 *   nlmsg_validate()			validate netlink message incl. attrs
  68 *   nlmsg_for_each_attr()		loop over all attributes
  69 *
  70 * Misc:
  71 *   nlmsg_report()			report back to application?
  72 *
  73 * ------------------------------------------------------------------------
  74 *                          Attributes Interface
  75 * ------------------------------------------------------------------------
  76 *
  77 * Attribute Format:
  78 *    <------- nla_total_size(payload) ------->
  79 *    <---- nla_attr_size(payload) ----->
  80 *   +----------+- - -+- - - - - - - - - +- - -+-------- - -
  81 *   |  Header  | Pad |     Payload      | Pad |  Header
  82 *   +----------+- - -+- - - - - - - - - +- - -+-------- - -
  83 *                     <- nla_len(nla) ->      ^
  84 *   nla_data(nla)----^                        |
  85 *   nla_next(nla)-----------------------------'
  86 *
  87 * Data Structures:
  88 *   struct nlattr			netlink attribute header
  89 *
  90 * Attribute Construction:
  91 *   nla_reserve(skb, type, len)	reserve room for an attribute
  92 *   nla_reserve_nohdr(skb, len)	reserve room for an attribute w/o hdr
  93 *   nla_put(skb, type, len, data)	add attribute to skb
  94 *   nla_put_nohdr(skb, len, data)	add attribute w/o hdr
  95 *   nla_append(skb, len, data)		append data to skb
  96 *
  97 * Attribute Construction for Basic Types:
  98 *   nla_put_u8(skb, type, value)	add u8 attribute to skb
  99 *   nla_put_u16(skb, type, value)	add u16 attribute to skb
 100 *   nla_put_u32(skb, type, value)	add u32 attribute to skb
 101 *   nla_put_u64(skb, type, value)	add u64 attribute to skb
 102 *   nla_put_s8(skb, type, value)	add s8 attribute to skb
 103 *   nla_put_s16(skb, type, value)	add s16 attribute to skb
 104 *   nla_put_s32(skb, type, value)	add s32 attribute to skb
 105 *   nla_put_s64(skb, type, value)	add s64 attribute to skb
 106 *   nla_put_string(skb, type, str)	add string attribute to skb
 107 *   nla_put_flag(skb, type)		add flag attribute to skb
 108 *   nla_put_msecs(skb, type, jiffies)	add msecs attribute to skb
 109 *   nla_put_in_addr(skb, type, addr)	add IPv4 address attribute to skb
 110 *   nla_put_in6_addr(skb, type, addr)	add IPv6 address attribute to skb
 111 *
 112 * Nested Attributes Construction:
 113 *   nla_nest_start(skb, type)		start a nested attribute
 114 *   nla_nest_end(skb, nla)		finalize a nested attribute
 115 *   nla_nest_cancel(skb, nla)		cancel nested attribute construction
 116 *
 117 * Attribute Length Calculations:
 118 *   nla_attr_size(payload)		length of attribute w/o padding
 119 *   nla_total_size(payload)		length of attribute w/ padding
 120 *   nla_padlen(payload)		length of padding
 121 *
 122 * Attribute Payload Access:
 123 *   nla_data(nla)			head of attribute payload
 124 *   nla_len(nla)			length of attribute payload
 125 *
 126 * Attribute Payload Access for Basic Types:
 127 *   nla_get_u8(nla)			get payload for a u8 attribute
 128 *   nla_get_u16(nla)			get payload for a u16 attribute
 129 *   nla_get_u32(nla)			get payload for a u32 attribute
 130 *   nla_get_u64(nla)			get payload for a u64 attribute
 131 *   nla_get_s8(nla)			get payload for a s8 attribute
 132 *   nla_get_s16(nla)			get payload for a s16 attribute
 133 *   nla_get_s32(nla)			get payload for a s32 attribute
 134 *   nla_get_s64(nla)			get payload for a s64 attribute
 135 *   nla_get_flag(nla)			return 1 if flag is true
 136 *   nla_get_msecs(nla)			get payload for a msecs attribute
 137 *
 138 * Attribute Misc:
 139 *   nla_memcpy(dest, nla, count)	copy attribute into memory
 140 *   nla_memcmp(nla, data, size)	compare attribute with memory area
 141 *   nla_strlcpy(dst, nla, size)	copy attribute to a sized string
 142 *   nla_strcmp(nla, str)		compare attribute with string
 143 *
 144 * Attribute Parsing:
 145 *   nla_ok(nla, remaining)		does nla fit into remaining bytes?
 146 *   nla_next(nla, remaining)		get next netlink attribute
 147 *   nla_validate()			validate a stream of attributes
 148 *   nla_validate_nested()		validate a stream of nested attributes
 149 *   nla_find()				find attribute in stream of attributes
 150 *   nla_find_nested()			find attribute in nested attributes
 151 *   nla_parse()			parse and validate stream of attrs
 152 *   nla_parse_nested()			parse nested attribuets
 153 *   nla_for_each_attr()		loop over all attributes
 154 *   nla_for_each_nested()		loop over the nested attributes
 155 *=========================================================================
 156 */
 157
 158 /**
 159  * Standard attribute types to specify validation policy
 160  */
 161enum {
 162	NLA_UNSPEC,
 163	NLA_U8,
 164	NLA_U16,
 165	NLA_U32,
 166	NLA_U64,
 167	NLA_STRING,
 168	NLA_FLAG,
 169	NLA_MSECS,
 170	NLA_NESTED,
 171	NLA_NESTED_COMPAT,
 172	NLA_NUL_STRING,
 173	NLA_BINARY,
 174	NLA_S8,
 175	NLA_S16,
 176	NLA_S32,
 177	NLA_S64,
 178	__NLA_TYPE_MAX,
 179};
 180
 181#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
 182
 183/**
 184 * struct nla_policy - attribute validation policy
 185 * @type: Type of attribute or NLA_UNSPEC
 186 * @len: Type specific length of payload
 187 *
 188 * Policies are defined as arrays of this struct, the array must be
 189 * accessible by attribute type up to the highest identifier to be expected.
 190 *
 191 * Meaning of `len' field:
 192 *    NLA_STRING           Maximum length of string
 193 *    NLA_NUL_STRING       Maximum length of string (excluding NUL)
 194 *    NLA_FLAG             Unused
 195 *    NLA_BINARY           Maximum length of attribute payload
 196 *    NLA_NESTED           Don't use `len' field -- length verification is
 197 *                         done by checking len of nested header (or empty)
 198 *    NLA_NESTED_COMPAT    Minimum length of structure payload
 199 *    NLA_U8, NLA_U16,
 200 *    NLA_U32, NLA_U64,
 201 *    NLA_S8, NLA_S16,
 202 *    NLA_S32, NLA_S64,
 203 *    NLA_MSECS            Leaving the length field zero will verify the
 204 *                         given type fits, using it verifies minimum length
 205 *                         just like "All other"
 206 *    All other            Minimum length of attribute payload
 207 *
 208 * Example:
 209 * static const struct nla_policy my_policy[ATTR_MAX+1] = {
 210 * 	[ATTR_FOO] = { .type = NLA_U16 },
 211 *	[ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
 212 *	[ATTR_BAZ] = { .len = sizeof(struct mystruct) },
 213 * };
 214 */
 215struct nla_policy {
 216	u16		type;
 217	u16		len;
 218};
 219
 220/**
 221 * struct nl_info - netlink source information
 222 * @nlh: Netlink message header of original request
 223 * @portid: Netlink PORTID of requesting application
 224 */
 225struct nl_info {
 226	struct nlmsghdr		*nlh;
 227	struct net		*nl_net;
 228	u32			portid;
 229};
 230
 231int netlink_rcv_skb(struct sk_buff *skb,
 232		    int (*cb)(struct sk_buff *, struct nlmsghdr *));
 233int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
 234		 unsigned int group, int report, gfp_t flags);
 235
 236int nla_validate(const struct nlattr *head, int len, int maxtype,
 237		 const struct nla_policy *policy);
 238int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
 239	      int len, const struct nla_policy *policy);
 240int nla_policy_len(const struct nla_policy *, int);
 241struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
 242size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
 243int nla_memcpy(void *dest, const struct nlattr *src, int count);
 244int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
 245int nla_strcmp(const struct nlattr *nla, const char *str);
 246struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
 247void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
 248struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
 249void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
 250void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
 251	       const void *data);
 252void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
 253int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
 254int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
 255int nla_append(struct sk_buff *skb, int attrlen, const void *data);
 
 
 
 
 
 
 
 
 
 
 
 
 
 256
 257/**************************************************************************
 258 * Netlink Messages
 259 **************************************************************************/
 260
 261/**
 262 * nlmsg_msg_size - length of netlink message not including padding
 263 * @payload: length of message payload
 264 */
 265static inline int nlmsg_msg_size(int payload)
 266{
 267	return NLMSG_HDRLEN + payload;
 268}
 269
 270/**
 271 * nlmsg_total_size - length of netlink message including padding
 272 * @payload: length of message payload
 273 */
 274static inline int nlmsg_total_size(int payload)
 275{
 276	return NLMSG_ALIGN(nlmsg_msg_size(payload));
 277}
 278
 279/**
 280 * nlmsg_padlen - length of padding at the message's tail
 281 * @payload: length of message payload
 282 */
 283static inline int nlmsg_padlen(int payload)
 284{
 285	return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
 286}
 287
 288/**
 289 * nlmsg_data - head of message payload
 290 * @nlh: netlink message header
 291 */
 292static inline void *nlmsg_data(const struct nlmsghdr *nlh)
 293{
 294	return (unsigned char *) nlh + NLMSG_HDRLEN;
 295}
 296
 297/**
 298 * nlmsg_len - length of message payload
 299 * @nlh: netlink message header
 300 */
 301static inline int nlmsg_len(const struct nlmsghdr *nlh)
 302{
 303	return nlh->nlmsg_len - NLMSG_HDRLEN;
 304}
 305
 306/**
 307 * nlmsg_attrdata - head of attributes data
 308 * @nlh: netlink message header
 309 * @hdrlen: length of family specific header
 310 */
 311static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
 312					    int hdrlen)
 313{
 314	unsigned char *data = nlmsg_data(nlh);
 315	return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
 316}
 317
 318/**
 319 * nlmsg_attrlen - length of attributes data
 320 * @nlh: netlink message header
 321 * @hdrlen: length of family specific header
 322 */
 323static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
 324{
 325	return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
 326}
 327
 328/**
 329 * nlmsg_ok - check if the netlink message fits into the remaining bytes
 330 * @nlh: netlink message header
 331 * @remaining: number of bytes remaining in message stream
 332 */
 333static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
 334{
 335	return (remaining >= (int) sizeof(struct nlmsghdr) &&
 336		nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
 337		nlh->nlmsg_len <= remaining);
 338}
 339
 340/**
 341 * nlmsg_next - next netlink message in message stream
 342 * @nlh: netlink message header
 343 * @remaining: number of bytes remaining in message stream
 344 *
 345 * Returns the next netlink message in the message stream and
 346 * decrements remaining by the size of the current message.
 347 */
 348static inline struct nlmsghdr *
 349nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
 350{
 351	int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
 352
 353	*remaining -= totlen;
 354
 355	return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
 356}
 357
 358/**
 359 * nlmsg_parse - parse attributes of a netlink message
 360 * @nlh: netlink message header
 361 * @hdrlen: length of family specific header
 362 * @tb: destination array with maxtype+1 elements
 363 * @maxtype: maximum attribute type to be expected
 364 * @policy: validation policy
 365 *
 366 * See nla_parse()
 367 */
 368static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
 369			      struct nlattr *tb[], int maxtype,
 370			      const struct nla_policy *policy)
 371{
 372	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
 373		return -EINVAL;
 374
 375	return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
 376			 nlmsg_attrlen(nlh, hdrlen), policy);
 377}
 378
 379/**
 380 * nlmsg_find_attr - find a specific attribute in a netlink message
 381 * @nlh: netlink message header
 382 * @hdrlen: length of familiy specific header
 383 * @attrtype: type of attribute to look for
 384 *
 385 * Returns the first attribute which matches the specified type.
 386 */
 387static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
 388					     int hdrlen, int attrtype)
 389{
 390	return nla_find(nlmsg_attrdata(nlh, hdrlen),
 391			nlmsg_attrlen(nlh, hdrlen), attrtype);
 392}
 393
 394/**
 395 * nlmsg_validate - validate a netlink message including attributes
 396 * @nlh: netlinket message header
 397 * @hdrlen: length of familiy specific header
 398 * @maxtype: maximum attribute type to be expected
 399 * @policy: validation policy
 400 */
 401static inline int nlmsg_validate(const struct nlmsghdr *nlh,
 402				 int hdrlen, int maxtype,
 403				 const struct nla_policy *policy)
 404{
 405	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
 406		return -EINVAL;
 407
 408	return nla_validate(nlmsg_attrdata(nlh, hdrlen),
 409			    nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
 410}
 411
 412/**
 413 * nlmsg_report - need to report back to application?
 414 * @nlh: netlink message header
 415 *
 416 * Returns 1 if a report back to the application is requested.
 417 */
 418static inline int nlmsg_report(const struct nlmsghdr *nlh)
 419{
 420	return !!(nlh->nlmsg_flags & NLM_F_ECHO);
 421}
 422
 423/**
 424 * nlmsg_for_each_attr - iterate over a stream of attributes
 425 * @pos: loop counter, set to current attribute
 426 * @nlh: netlink message header
 427 * @hdrlen: length of familiy specific header
 428 * @rem: initialized to len, holds bytes currently remaining in stream
 429 */
 430#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
 431	nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
 432			  nlmsg_attrlen(nlh, hdrlen), rem)
 433
 434/**
 435 * nlmsg_put - Add a new netlink message to an skb
 436 * @skb: socket buffer to store message in
 437 * @portid: netlink PORTID of requesting application
 438 * @seq: sequence number of message
 439 * @type: message type
 440 * @payload: length of message payload
 441 * @flags: message flags
 442 *
 443 * Returns NULL if the tailroom of the skb is insufficient to store
 444 * the message header and payload.
 445 */
 446static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
 447					 int type, int payload, int flags)
 448{
 449	if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
 450		return NULL;
 451
 452	return __nlmsg_put(skb, portid, seq, type, payload, flags);
 453}
 454
 455/**
 456 * nlmsg_put_answer - Add a new callback based netlink message to an skb
 457 * @skb: socket buffer to store message in
 458 * @cb: netlink callback
 459 * @type: message type
 460 * @payload: length of message payload
 461 * @flags: message flags
 462 *
 463 * Returns NULL if the tailroom of the skb is insufficient to store
 464 * the message header and payload.
 465 */
 466static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
 467						struct netlink_callback *cb,
 468						int type, int payload,
 469						int flags)
 470{
 471	return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 472			 type, payload, flags);
 473}
 474
 475/**
 476 * nlmsg_new - Allocate a new netlink message
 477 * @payload: size of the message payload
 478 * @flags: the type of memory to allocate.
 479 *
 480 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
 481 * and a good default is needed.
 482 */
 483static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
 484{
 485	return alloc_skb(nlmsg_total_size(payload), flags);
 486}
 487
 488/**
 489 * nlmsg_end - Finalize a netlink message
 490 * @skb: socket buffer the message is stored in
 491 * @nlh: netlink message header
 492 *
 493 * Corrects the netlink message header to include the appeneded
 494 * attributes. Only necessary if attributes have been added to
 495 * the message.
 
 
 496 */
 497static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
 498{
 499	nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
 
 
 500}
 501
 502/**
 503 * nlmsg_get_pos - return current position in netlink message
 504 * @skb: socket buffer the message is stored in
 505 *
 506 * Returns a pointer to the current tail of the message.
 507 */
 508static inline void *nlmsg_get_pos(struct sk_buff *skb)
 509{
 510	return skb_tail_pointer(skb);
 511}
 512
 513/**
 514 * nlmsg_trim - Trim message to a mark
 515 * @skb: socket buffer the message is stored in
 516 * @mark: mark to trim to
 517 *
 518 * Trims the message to the provided mark.
 519 */
 520static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
 521{
 522	if (mark) {
 523		WARN_ON((unsigned char *) mark < skb->data);
 524		skb_trim(skb, (unsigned char *) mark - skb->data);
 525	}
 526}
 527
 528/**
 529 * nlmsg_cancel - Cancel construction of a netlink message
 530 * @skb: socket buffer the message is stored in
 531 * @nlh: netlink message header
 532 *
 533 * Removes the complete netlink message including all
 534 * attributes from the socket buffer again.
 535 */
 536static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
 537{
 538	nlmsg_trim(skb, nlh);
 539}
 540
 541/**
 542 * nlmsg_free - free a netlink message
 543 * @skb: socket buffer of netlink message
 544 */
 545static inline void nlmsg_free(struct sk_buff *skb)
 546{
 547	kfree_skb(skb);
 548}
 549
 550/**
 551 * nlmsg_multicast - multicast a netlink message
 552 * @sk: netlink socket to spread messages to
 553 * @skb: netlink message as socket buffer
 554 * @portid: own netlink portid to avoid sending to yourself
 555 * @group: multicast group id
 556 * @flags: allocation flags
 557 */
 558static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
 559				  u32 portid, unsigned int group, gfp_t flags)
 560{
 561	int err;
 562
 563	NETLINK_CB(skb).dst_group = group;
 564
 565	err = netlink_broadcast(sk, skb, portid, group, flags);
 566	if (err > 0)
 567		err = 0;
 568
 569	return err;
 570}
 571
 572/**
 573 * nlmsg_unicast - unicast a netlink message
 574 * @sk: netlink socket to spread message to
 575 * @skb: netlink message as socket buffer
 576 * @portid: netlink portid of the destination socket
 577 */
 578static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
 579{
 580	int err;
 581
 582	err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
 583	if (err > 0)
 584		err = 0;
 585
 586	return err;
 587}
 588
 589/**
 590 * nlmsg_for_each_msg - iterate over a stream of messages
 591 * @pos: loop counter, set to current message
 592 * @head: head of message stream
 593 * @len: length of message stream
 594 * @rem: initialized to len, holds bytes currently remaining in stream
 595 */
 596#define nlmsg_for_each_msg(pos, head, len, rem) \
 597	for (pos = head, rem = len; \
 598	     nlmsg_ok(pos, rem); \
 599	     pos = nlmsg_next(pos, &(rem)))
 600
 601/**
 602 * nl_dump_check_consistent - check if sequence is consistent and advertise if not
 603 * @cb: netlink callback structure that stores the sequence number
 604 * @nlh: netlink message header to write the flag to
 605 *
 606 * This function checks if the sequence (generation) number changed during dump
 607 * and if it did, advertises it in the netlink message header.
 608 *
 609 * The correct way to use it is to set cb->seq to the generation counter when
 610 * all locks for dumping have been acquired, and then call this function for
 611 * each message that is generated.
 612 *
 613 * Note that due to initialisation concerns, 0 is an invalid sequence number
 614 * and must not be used by code that uses this functionality.
 615 */
 616static inline void
 617nl_dump_check_consistent(struct netlink_callback *cb,
 618			 struct nlmsghdr *nlh)
 619{
 620	if (cb->prev_seq && cb->seq != cb->prev_seq)
 621		nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
 622	cb->prev_seq = cb->seq;
 623}
 624
 625/**************************************************************************
 626 * Netlink Attributes
 627 **************************************************************************/
 628
 629/**
 630 * nla_attr_size - length of attribute not including padding
 631 * @payload: length of payload
 632 */
 633static inline int nla_attr_size(int payload)
 634{
 635	return NLA_HDRLEN + payload;
 636}
 637
 638/**
 639 * nla_total_size - total length of attribute including padding
 640 * @payload: length of payload
 641 */
 642static inline int nla_total_size(int payload)
 643{
 644	return NLA_ALIGN(nla_attr_size(payload));
 645}
 646
 647/**
 648 * nla_padlen - length of padding at the tail of attribute
 649 * @payload: length of payload
 650 */
 651static inline int nla_padlen(int payload)
 652{
 653	return nla_total_size(payload) - nla_attr_size(payload);
 654}
 655
 656/**
 657 * nla_type - attribute type
 658 * @nla: netlink attribute
 659 */
 660static inline int nla_type(const struct nlattr *nla)
 661{
 662	return nla->nla_type & NLA_TYPE_MASK;
 663}
 664
 665/**
 666 * nla_data - head of payload
 667 * @nla: netlink attribute
 668 */
 669static inline void *nla_data(const struct nlattr *nla)
 670{
 671	return (char *) nla + NLA_HDRLEN;
 672}
 673
 674/**
 675 * nla_len - length of payload
 676 * @nla: netlink attribute
 677 */
 678static inline int nla_len(const struct nlattr *nla)
 679{
 680	return nla->nla_len - NLA_HDRLEN;
 681}
 682
 683/**
 684 * nla_ok - check if the netlink attribute fits into the remaining bytes
 685 * @nla: netlink attribute
 686 * @remaining: number of bytes remaining in attribute stream
 687 */
 688static inline int nla_ok(const struct nlattr *nla, int remaining)
 689{
 690	return remaining >= (int) sizeof(*nla) &&
 691	       nla->nla_len >= sizeof(*nla) &&
 692	       nla->nla_len <= remaining;
 693}
 694
 695/**
 696 * nla_next - next netlink attribute in attribute stream
 697 * @nla: netlink attribute
 698 * @remaining: number of bytes remaining in attribute stream
 699 *
 700 * Returns the next netlink attribute in the attribute stream and
 701 * decrements remaining by the size of the current attribute.
 702 */
 703static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
 704{
 705	int totlen = NLA_ALIGN(nla->nla_len);
 706
 707	*remaining -= totlen;
 708	return (struct nlattr *) ((char *) nla + totlen);
 709}
 710
 711/**
 712 * nla_find_nested - find attribute in a set of nested attributes
 713 * @nla: attribute containing the nested attributes
 714 * @attrtype: type of attribute to look for
 715 *
 716 * Returns the first attribute which matches the specified type.
 717 */
 718static inline struct nlattr *
 719nla_find_nested(const struct nlattr *nla, int attrtype)
 720{
 721	return nla_find(nla_data(nla), nla_len(nla), attrtype);
 722}
 723
 724/**
 725 * nla_parse_nested - parse nested attributes
 726 * @tb: destination array with maxtype+1 elements
 727 * @maxtype: maximum attribute type to be expected
 728 * @nla: attribute containing the nested attributes
 729 * @policy: validation policy
 730 *
 731 * See nla_parse()
 732 */
 733static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
 734				   const struct nlattr *nla,
 735				   const struct nla_policy *policy)
 736{
 737	return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
 738}
 739
 740/**
 741 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
 742 * @skb: socket buffer to add attribute to
 743 * @attrtype: attribute type
 744 * @value: numeric value
 745 */
 746static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
 747{
 748	return nla_put(skb, attrtype, sizeof(u8), &value);
 749}
 750
 751/**
 752 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
 753 * @skb: socket buffer to add attribute to
 754 * @attrtype: attribute type
 755 * @value: numeric value
 756 */
 757static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
 758{
 759	return nla_put(skb, attrtype, sizeof(u16), &value);
 760}
 761
 762/**
 763 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
 764 * @skb: socket buffer to add attribute to
 765 * @attrtype: attribute type
 766 * @value: numeric value
 767 */
 768static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
 769{
 770	return nla_put(skb, attrtype, sizeof(__be16), &value);
 771}
 772
 773/**
 774 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
 775 * @skb: socket buffer to add attribute to
 776 * @attrtype: attribute type
 777 * @value: numeric value
 778 */
 779static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
 780{
 781	return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, value);
 782}
 783
 784/**
 785 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
 786 * @skb: socket buffer to add attribute to
 787 * @attrtype: attribute type
 788 * @value: numeric value
 789 */
 790static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
 791{
 792	return nla_put(skb, attrtype, sizeof(__le16), &value);
 793}
 794
 795/**
 796 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
 797 * @skb: socket buffer to add attribute to
 798 * @attrtype: attribute type
 799 * @value: numeric value
 800 */
 801static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
 802{
 803	return nla_put(skb, attrtype, sizeof(u32), &value);
 804}
 805
 806/**
 807 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
 808 * @skb: socket buffer to add attribute to
 809 * @attrtype: attribute type
 810 * @value: numeric value
 811 */
 812static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
 813{
 814	return nla_put(skb, attrtype, sizeof(__be32), &value);
 815}
 816
 817/**
 818 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
 819 * @skb: socket buffer to add attribute to
 820 * @attrtype: attribute type
 821 * @value: numeric value
 822 */
 823static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
 824{
 825	return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, value);
 826}
 827
 828/**
 829 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
 830 * @skb: socket buffer to add attribute to
 831 * @attrtype: attribute type
 832 * @value: numeric value
 833 */
 834static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
 835{
 836	return nla_put(skb, attrtype, sizeof(__le32), &value);
 837}
 838
 839/**
 840 * nla_put_u64 - Add a u64 netlink attribute to a socket buffer
 841 * @skb: socket buffer to add attribute to
 842 * @attrtype: attribute type
 843 * @value: numeric value
 844 */
 845static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
 846{
 847	return nla_put(skb, attrtype, sizeof(u64), &value);
 848}
 849
 850/**
 851 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer
 852 * @skb: socket buffer to add attribute to
 853 * @attrtype: attribute type
 854 * @value: numeric value
 855 */
 856static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value)
 857{
 858	return nla_put(skb, attrtype, sizeof(__be64), &value);
 859}
 860
 861/**
 862 * nla_put_net64 - Add 64-bit network byte order netlink attribute to a socket buffer
 863 * @skb: socket buffer to add attribute to
 864 * @attrtype: attribute type
 865 * @value: numeric value
 866 */
 867static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value)
 868{
 869	return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, value);
 870}
 871
 872/**
 873 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer
 874 * @skb: socket buffer to add attribute to
 875 * @attrtype: attribute type
 876 * @value: numeric value
 877 */
 878static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value)
 879{
 880	return nla_put(skb, attrtype, sizeof(__le64), &value);
 881}
 882
 883/**
 884 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
 885 * @skb: socket buffer to add attribute to
 886 * @attrtype: attribute type
 887 * @value: numeric value
 888 */
 889static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
 890{
 891	return nla_put(skb, attrtype, sizeof(s8), &value);
 892}
 893
 894/**
 895 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
 896 * @skb: socket buffer to add attribute to
 897 * @attrtype: attribute type
 898 * @value: numeric value
 899 */
 900static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
 901{
 902	return nla_put(skb, attrtype, sizeof(s16), &value);
 903}
 904
 905/**
 906 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
 907 * @skb: socket buffer to add attribute to
 908 * @attrtype: attribute type
 909 * @value: numeric value
 910 */
 911static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
 912{
 913	return nla_put(skb, attrtype, sizeof(s32), &value);
 914}
 915
 916/**
 917 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer
 918 * @skb: socket buffer to add attribute to
 919 * @attrtype: attribute type
 920 * @value: numeric value
 921 */
 922static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value)
 923{
 924	return nla_put(skb, attrtype, sizeof(s64), &value);
 925}
 926
 927/**
 928 * nla_put_string - Add a string netlink attribute to a socket buffer
 929 * @skb: socket buffer to add attribute to
 930 * @attrtype: attribute type
 931 * @str: NUL terminated string
 932 */
 933static inline int nla_put_string(struct sk_buff *skb, int attrtype,
 934				 const char *str)
 935{
 936	return nla_put(skb, attrtype, strlen(str) + 1, str);
 937}
 938
 939/**
 940 * nla_put_flag - Add a flag netlink attribute to a socket buffer
 941 * @skb: socket buffer to add attribute to
 942 * @attrtype: attribute type
 943 */
 944static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
 945{
 946	return nla_put(skb, attrtype, 0, NULL);
 947}
 948
 949/**
 950 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer
 951 * @skb: socket buffer to add attribute to
 952 * @attrtype: attribute type
 953 * @njiffies: number of jiffies to convert to msecs
 954 */
 955static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
 956				unsigned long njiffies)
 957{
 958	u64 tmp = jiffies_to_msecs(njiffies);
 959	return nla_put(skb, attrtype, sizeof(u64), &tmp);
 960}
 961
 962/**
 963 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
 964 * buffer
 965 * @skb: socket buffer to add attribute to
 966 * @attrtype: attribute type
 967 * @addr: IPv4 address
 968 */
 969static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
 970				  __be32 addr)
 971{
 972	return nla_put_be32(skb, attrtype, addr);
 973}
 974
 975/**
 976 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
 977 * buffer
 978 * @skb: socket buffer to add attribute to
 979 * @attrtype: attribute type
 980 * @addr: IPv6 address
 981 */
 982static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
 983				   const struct in6_addr *addr)
 984{
 985	return nla_put(skb, attrtype, sizeof(*addr), addr);
 986}
 987
 988/**
 989 * nla_get_u32 - return payload of u32 attribute
 990 * @nla: u32 netlink attribute
 991 */
 992static inline u32 nla_get_u32(const struct nlattr *nla)
 993{
 994	return *(u32 *) nla_data(nla);
 995}
 996
 997/**
 998 * nla_get_be32 - return payload of __be32 attribute
 999 * @nla: __be32 netlink attribute
1000 */
1001static inline __be32 nla_get_be32(const struct nlattr *nla)
1002{
1003	return *(__be32 *) nla_data(nla);
1004}
1005
1006/**
1007 * nla_get_le32 - return payload of __le32 attribute
1008 * @nla: __le32 netlink attribute
1009 */
1010static inline __le32 nla_get_le32(const struct nlattr *nla)
1011{
1012	return *(__le32 *) nla_data(nla);
1013}
1014
1015/**
1016 * nla_get_u16 - return payload of u16 attribute
1017 * @nla: u16 netlink attribute
1018 */
1019static inline u16 nla_get_u16(const struct nlattr *nla)
1020{
1021	return *(u16 *) nla_data(nla);
1022}
1023
1024/**
1025 * nla_get_be16 - return payload of __be16 attribute
1026 * @nla: __be16 netlink attribute
1027 */
1028static inline __be16 nla_get_be16(const struct nlattr *nla)
1029{
1030	return *(__be16 *) nla_data(nla);
1031}
1032
1033/**
1034 * nla_get_le16 - return payload of __le16 attribute
1035 * @nla: __le16 netlink attribute
1036 */
1037static inline __le16 nla_get_le16(const struct nlattr *nla)
1038{
1039	return *(__le16 *) nla_data(nla);
1040}
1041
1042/**
1043 * nla_get_u8 - return payload of u8 attribute
1044 * @nla: u8 netlink attribute
1045 */
1046static inline u8 nla_get_u8(const struct nlattr *nla)
1047{
1048	return *(u8 *) nla_data(nla);
1049}
1050
1051/**
1052 * nla_get_u64 - return payload of u64 attribute
1053 * @nla: u64 netlink attribute
1054 */
1055static inline u64 nla_get_u64(const struct nlattr *nla)
1056{
1057	u64 tmp;
1058
1059	nla_memcpy(&tmp, nla, sizeof(tmp));
1060
1061	return tmp;
1062}
1063
1064/**
1065 * nla_get_be64 - return payload of __be64 attribute
1066 * @nla: __be64 netlink attribute
1067 */
1068static inline __be64 nla_get_be64(const struct nlattr *nla)
1069{
1070	__be64 tmp;
1071
1072	nla_memcpy(&tmp, nla, sizeof(tmp));
1073
1074	return tmp;
1075}
1076
1077/**
1078 * nla_get_le64 - return payload of __le64 attribute
1079 * @nla: __le64 netlink attribute
1080 */
1081static inline __le64 nla_get_le64(const struct nlattr *nla)
1082{
1083	return *(__le64 *) nla_data(nla);
1084}
1085
1086/**
1087 * nla_get_s32 - return payload of s32 attribute
1088 * @nla: s32 netlink attribute
1089 */
1090static inline s32 nla_get_s32(const struct nlattr *nla)
1091{
1092	return *(s32 *) nla_data(nla);
1093}
1094
1095/**
1096 * nla_get_s16 - return payload of s16 attribute
1097 * @nla: s16 netlink attribute
1098 */
1099static inline s16 nla_get_s16(const struct nlattr *nla)
1100{
1101	return *(s16 *) nla_data(nla);
1102}
1103
1104/**
1105 * nla_get_s8 - return payload of s8 attribute
1106 * @nla: s8 netlink attribute
1107 */
1108static inline s8 nla_get_s8(const struct nlattr *nla)
1109{
1110	return *(s8 *) nla_data(nla);
1111}
1112
1113/**
1114 * nla_get_s64 - return payload of s64 attribute
1115 * @nla: s64 netlink attribute
1116 */
1117static inline s64 nla_get_s64(const struct nlattr *nla)
1118{
1119	s64 tmp;
1120
1121	nla_memcpy(&tmp, nla, sizeof(tmp));
1122
1123	return tmp;
1124}
1125
1126/**
1127 * nla_get_flag - return payload of flag attribute
1128 * @nla: flag netlink attribute
1129 */
1130static inline int nla_get_flag(const struct nlattr *nla)
1131{
1132	return !!nla;
1133}
1134
1135/**
1136 * nla_get_msecs - return payload of msecs attribute
1137 * @nla: msecs netlink attribute
1138 *
1139 * Returns the number of milliseconds in jiffies.
1140 */
1141static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1142{
1143	u64 msecs = nla_get_u64(nla);
1144
1145	return msecs_to_jiffies((unsigned long) msecs);
1146}
1147
1148/**
1149 * nla_get_in_addr - return payload of IPv4 address attribute
1150 * @nla: IPv4 address netlink attribute
1151 */
1152static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1153{
1154	return *(__be32 *) nla_data(nla);
1155}
1156
1157/**
1158 * nla_get_in6_addr - return payload of IPv6 address attribute
1159 * @nla: IPv6 address netlink attribute
1160 */
1161static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1162{
1163	struct in6_addr tmp;
1164
1165	nla_memcpy(&tmp, nla, sizeof(tmp));
1166	return tmp;
1167}
1168
1169/**
1170 * nla_nest_start - Start a new level of nested attributes
1171 * @skb: socket buffer to add attributes to
1172 * @attrtype: attribute type of container
1173 *
1174 * Returns the container attribute
1175 */
1176static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1177{
1178	struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1179
1180	if (nla_put(skb, attrtype, 0, NULL) < 0)
1181		return NULL;
1182
1183	return start;
1184}
1185
1186/**
1187 * nla_nest_end - Finalize nesting of attributes
1188 * @skb: socket buffer the attributes are stored in
1189 * @start: container attribute
1190 *
1191 * Corrects the container attribute header to include the all
1192 * appeneded attributes.
1193 *
1194 * Returns the total data length of the skb.
1195 */
1196static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1197{
1198	start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1199	return skb->len;
1200}
1201
1202/**
1203 * nla_nest_cancel - Cancel nesting of attributes
1204 * @skb: socket buffer the message is stored in
1205 * @start: container attribute
1206 *
1207 * Removes the container attribute and including all nested
1208 * attributes. Returns -EMSGSIZE
1209 */
1210static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1211{
1212	nlmsg_trim(skb, start);
1213}
1214
1215/**
1216 * nla_validate_nested - Validate a stream of nested attributes
1217 * @start: container attribute
1218 * @maxtype: maximum attribute type to be expected
1219 * @policy: validation policy
1220 *
1221 * Validates all attributes in the nested attribute stream against the
1222 * specified policy. Attributes with a type exceeding maxtype will be
1223 * ignored. See documenation of struct nla_policy for more details.
1224 *
1225 * Returns 0 on success or a negative error code.
1226 */
1227static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
1228				      const struct nla_policy *policy)
1229{
1230	return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
1231}
1232
1233/**
1234 * nla_for_each_attr - iterate over a stream of attributes
1235 * @pos: loop counter, set to current attribute
1236 * @head: head of attribute stream
1237 * @len: length of attribute stream
1238 * @rem: initialized to len, holds bytes currently remaining in stream
1239 */
1240#define nla_for_each_attr(pos, head, len, rem) \
1241	for (pos = head, rem = len; \
1242	     nla_ok(pos, rem); \
1243	     pos = nla_next(pos, &(rem)))
1244
1245/**
1246 * nla_for_each_nested - iterate over nested attributes
1247 * @pos: loop counter, set to current attribute
1248 * @nla: attribute containing the nested attributes
1249 * @rem: initialized to len, holds bytes currently remaining in stream
1250 */
1251#define nla_for_each_nested(pos, nla, rem) \
1252	nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1253
1254/**
1255 * nla_is_last - Test if attribute is last in stream
1256 * @nla: attribute to test
1257 * @rem: bytes remaining in stream
1258 */
1259static inline bool nla_is_last(const struct nlattr *nla, int rem)
1260{
1261	return nla->nla_len == rem;
1262}
1263
1264#endif