include/net/netlink.h

   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   */
 161 enum {
 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  */
 215 struct 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  */
 225 struct nl_info {
 226         struct nlmsghdr         *nlh;
 227         struct net              *nl_net;
 228         u32                     portid;
 229 };
 230
 231 int netlink_rcv_skb(struct sk_buff *skb,
 232                     int (*cb)(struct sk_buff *, struct nlmsghdr *));
 233 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
 234                  unsigned int group, int report, gfp_t flags);
 235
 236 int nla_validate(const struct nlattr *head, int len, int maxtype,
 237                  const struct nla_policy *policy);
 238 int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
 239               int len, const struct nla_policy *policy);
 240 int nla_policy_len(const struct nla_policy *, int);
 241 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
 242 size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
 243 int nla_memcpy(void *dest, const struct nlattr *src, int count);
 244 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
 245 int nla_strcmp(const struct nlattr *nla, const char *str);
 246 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
 247 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
 248                                    int attrlen, int padattr);
 249 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
 250 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
 251 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
 252                                  int attrlen, int padattr);
 253 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
 254 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
 255                const void *data);
 256 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
 257                      const void *data, int padattr);
 258 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
 259 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
 260 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
 261                   const void *data, int padattr);
 262 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
 263 int nla_append(struct sk_buff *skb, int attrlen, const void *data);
 264
 265 /**************************************************************************
 266  * Netlink Messages
 267  **************************************************************************/
 268
 269 /**
 270  * nlmsg_msg_size - length of netlink message not including padding
 271  * @payload: length of message payload
 272  */
 273 static inline int nlmsg_msg_size(int payload)
 274 {
 275         return NLMSG_HDRLEN + payload;
 276 }
 277
 278 /**
 279  * nlmsg_total_size - length of netlink message including padding
 280  * @payload: length of message payload
 281  */
 282 static inline int nlmsg_total_size(int payload)
 283 {
 284         return NLMSG_ALIGN(nlmsg_msg_size(payload));
 285 }
 286
 287 /**
 288  * nlmsg_padlen - length of padding at the message's tail
 289  * @payload: length of message payload
 290  */
 291 static inline int nlmsg_padlen(int payload)
 292 {
 293         return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
 294 }
 295
 296 /**
 297  * nlmsg_data - head of message payload
 298  * @nlh: netlink message header
 299  */
 300 static inline void *nlmsg_data(const struct nlmsghdr *nlh)
 301 {
 302         return (unsigned char *) nlh + NLMSG_HDRLEN;
 303 }
 304
 305 /**
 306  * nlmsg_len - length of message payload
 307  * @nlh: netlink message header
 308  */
 309 static inline int nlmsg_len(const struct nlmsghdr *nlh)
 310 {
 311         return nlh->nlmsg_len - NLMSG_HDRLEN;
 312 }
 313
 314 /**
 315  * nlmsg_attrdata - head of attributes data
 316  * @nlh: netlink message header
 317  * @hdrlen: length of family specific header
 318  */
 319 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
 320                                             int hdrlen)
 321 {
 322         unsigned char *data = nlmsg_data(nlh);
 323         return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
 324 }
 325
 326 /**
 327  * nlmsg_attrlen - length of attributes data
 328  * @nlh: netlink message header
 329  * @hdrlen: length of family specific header
 330  */
 331 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
 332 {
 333         return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
 334 }
 335
 336 /**
 337  * nlmsg_ok - check if the netlink message fits into the remaining bytes
 338  * @nlh: netlink message header
 339  * @remaining: number of bytes remaining in message stream
 340  */
 341 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
 342 {
 343         return (remaining >= (int) sizeof(struct nlmsghdr) &&
 344                 nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
 345                 nlh->nlmsg_len <= remaining);
 346 }
 347
 348 /**
 349  * nlmsg_next - next netlink message in message stream
 350  * @nlh: netlink message header
 351  * @remaining: number of bytes remaining in message stream
 352  *
 353  * Returns the next netlink message in the message stream and
 354  * decrements remaining by the size of the current message.
 355  */
 356 static inline struct nlmsghdr *
 357 nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
 358 {
 359         int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
 360
 361         *remaining -= totlen;
 362
 363         return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
 364 }
 365
 366 /**
 367  * nlmsg_parse - parse attributes of a netlink message
 368  * @nlh: netlink message header
 369  * @hdrlen: length of family specific header
 370  * @tb: destination array with maxtype+1 elements
 371  * @maxtype: maximum attribute type to be expected
 372  * @policy: validation policy
 373  *
 374  * See nla_parse()
 375  */
 376 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
 377                               struct nlattr *tb[], int maxtype,
 378                               const struct nla_policy *policy)
 379 {
 380         if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
 381                 return -EINVAL;
 382
 383         return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
 384                          nlmsg_attrlen(nlh, hdrlen), policy);
 385 }
 386
 387 /**
 388  * nlmsg_find_attr - find a specific attribute in a netlink message
 389  * @nlh: netlink message header
 390  * @hdrlen: length of familiy specific header
 391  * @attrtype: type of attribute to look for
 392  *
 393  * Returns the first attribute which matches the specified type.
 394  */
 395 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
 396                                              int hdrlen, int attrtype)
 397 {
 398         return nla_find(nlmsg_attrdata(nlh, hdrlen),
 399                         nlmsg_attrlen(nlh, hdrlen), attrtype);
 400 }
 401
 402 /**
 403  * nlmsg_validate - validate a netlink message including attributes
 404  * @nlh: netlinket message header
 405  * @hdrlen: length of familiy specific header
 406  * @maxtype: maximum attribute type to be expected
 407  * @policy: validation policy
 408  */
 409 static inline int nlmsg_validate(const struct nlmsghdr *nlh,
 410                                  int hdrlen, int maxtype,
 411                                  const struct nla_policy *policy)
 412 {
 413         if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
 414                 return -EINVAL;
 415
 416         return nla_validate(nlmsg_attrdata(nlh, hdrlen),
 417                             nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
 418 }
 419
 420 /**
 421  * nlmsg_report - need to report back to application?
 422  * @nlh: netlink message header
 423  *
 424  * Returns 1 if a report back to the application is requested.
 425  */
 426 static inline int nlmsg_report(const struct nlmsghdr *nlh)
 427 {
 428         return !!(nlh->nlmsg_flags & NLM_F_ECHO);
 429 }
 430
 431 /**
 432  * nlmsg_for_each_attr - iterate over a stream of attributes
 433  * @pos: loop counter, set to current attribute
 434  * @nlh: netlink message header
 435  * @hdrlen: length of familiy specific header
 436  * @rem: initialized to len, holds bytes currently remaining in stream
 437  */
 438 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
 439         nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
 440                           nlmsg_attrlen(nlh, hdrlen), rem)
 441
 442 /**
 443  * nlmsg_put - Add a new netlink message to an skb
 444  * @skb: socket buffer to store message in
 445  * @portid: netlink PORTID of requesting application
 446  * @seq: sequence number of message
 447  * @type: message type
 448  * @payload: length of message payload
 449  * @flags: message flags
 450  *
 451  * Returns NULL if the tailroom of the skb is insufficient to store
 452  * the message header and payload.
 453  */
 454 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
 455                                          int type, int payload, int flags)
 456 {
 457         if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
 458                 return NULL;
 459
 460         return __nlmsg_put(skb, portid, seq, type, payload, flags);
 461 }
 462
 463 /**
 464  * nlmsg_put_answer - Add a new callback based netlink message to an skb
 465  * @skb: socket buffer to store message in
 466  * @cb: netlink callback
 467  * @type: message type
 468  * @payload: length of message payload
 469  * @flags: message flags
 470  *
 471  * Returns NULL if the tailroom of the skb is insufficient to store
 472  * the message header and payload.
 473  */
 474 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
 475                                                 struct netlink_callback *cb,
 476                                                 int type, int payload,
 477                                                 int flags)
 478 {
 479         return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 480                          type, payload, flags);
 481 }
 482
 483 /**
 484  * nlmsg_new - Allocate a new netlink message
 485  * @payload: size of the message payload
 486  * @flags: the type of memory to allocate.
 487  *
 488  * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
 489  * and a good default is needed.
 490  */
 491 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
 492 {
 493         return alloc_skb(nlmsg_total_size(payload), flags);
 494 }
 495
 496 /**
 497  * nlmsg_end - Finalize a netlink message
 498  * @skb: socket buffer the message is stored in
 499  * @nlh: netlink message header
 500  *
 501  * Corrects the netlink message header to include the appeneded
 502  * attributes. Only necessary if attributes have been added to
 503  * the message.
 504  */
 505 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
 506 {
 507         nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
 508 }
 509
 510 /**
 511  * nlmsg_get_pos - return current position in netlink message
 512  * @skb: socket buffer the message is stored in
 513  *
 514  * Returns a pointer to the current tail of the message.
 515  */
 516 static inline void *nlmsg_get_pos(struct sk_buff *skb)
 517 {
 518         return skb_tail_pointer(skb);
 519 }
 520
 521 /**
 522  * nlmsg_trim - Trim message to a mark
 523  * @skb: socket buffer the message is stored in
 524  * @mark: mark to trim to
 525  *
 526  * Trims the message to the provided mark.
 527  */
 528 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
 529 {
 530         if (mark) {
 531                 WARN_ON((unsigned char *) mark < skb->data);
 532                 skb_trim(skb, (unsigned char *) mark - skb->data);
 533         }
 534 }
 535
 536 /**
 537  * nlmsg_cancel - Cancel construction of a netlink message
 538  * @skb: socket buffer the message is stored in
 539  * @nlh: netlink message header
 540  *
 541  * Removes the complete netlink message including all
 542  * attributes from the socket buffer again.
 543  */
 544 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
 545 {
 546         nlmsg_trim(skb, nlh);
 547 }
 548
 549 /**
 550  * nlmsg_free - free a netlink message
 551  * @skb: socket buffer of netlink message
 552  */
 553 static inline void nlmsg_free(struct sk_buff *skb)
 554 {
 555         kfree_skb(skb);
 556 }
 557
 558 /**
 559  * nlmsg_multicast - multicast a netlink message
 560  * @sk: netlink socket to spread messages to
 561  * @skb: netlink message as socket buffer
 562  * @portid: own netlink portid to avoid sending to yourself
 563  * @group: multicast group id
 564  * @flags: allocation flags
 565  */
 566 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
 567                                   u32 portid, unsigned int group, gfp_t flags)
 568 {
 569         int err;
 570
 571         NETLINK_CB(skb).dst_group = group;
 572
 573         err = netlink_broadcast(sk, skb, portid, group, flags);
 574         if (err > 0)
 575                 err = 0;
 576
 577         return err;
 578 }
 579
 580 /**
 581  * nlmsg_unicast - unicast a netlink message
 582  * @sk: netlink socket to spread message to
 583  * @skb: netlink message as socket buffer
 584  * @portid: netlink portid of the destination socket
 585  */
 586 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid)
 587 {
 588         int err;
 589
 590         err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT);
 591         if (err > 0)
 592                 err = 0;
 593
 594         return err;
 595 }
 596
 597 /**
 598  * nlmsg_for_each_msg - iterate over a stream of messages
 599  * @pos: loop counter, set to current message
 600  * @head: head of message stream
 601  * @len: length of message stream
 602  * @rem: initialized to len, holds bytes currently remaining in stream
 603  */
 604 #define nlmsg_for_each_msg(pos, head, len, rem) \
 605         for (pos = head, rem = len; \
 606              nlmsg_ok(pos, rem); \
 607              pos = nlmsg_next(pos, &(rem)))
 608
 609 /**
 610  * nl_dump_check_consistent - check if sequence is consistent and advertise if not
 611  * @cb: netlink callback structure that stores the sequence number
 612  * @nlh: netlink message header to write the flag to
 613  *
 614  * This function checks if the sequence (generation) number changed during dump
 615  * and if it did, advertises it in the netlink message header.
 616  *
 617  * The correct way to use it is to set cb->seq to the generation counter when
 618  * all locks for dumping have been acquired, and then call this function for
 619  * each message that is generated.
 620  *
 621  * Note that due to initialisation concerns, 0 is an invalid sequence number
 622  * and must not be used by code that uses this functionality.
 623  */
 624 static inline void
 625 nl_dump_check_consistent(struct netlink_callback *cb,
 626                          struct nlmsghdr *nlh)
 627 {
 628         if (cb->prev_seq && cb->seq != cb->prev_seq)
 629                 nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
 630         cb->prev_seq = cb->seq;
 631 }
 632
 633 /**************************************************************************
 634  * Netlink Attributes
 635  **************************************************************************/
 636
 637 /**
 638  * nla_attr_size - length of attribute not including padding
 639  * @payload: length of payload
 640  */
 641 static inline int nla_attr_size(int payload)
 642 {
 643         return NLA_HDRLEN + payload;
 644 }
 645
 646 /**
 647  * nla_total_size - total length of attribute including padding
 648  * @payload: length of payload
 649  */
 650 static inline int nla_total_size(int payload)
 651 {
 652         return NLA_ALIGN(nla_attr_size(payload));
 653 }
 654
 655 /**
 656  * nla_padlen - length of padding at the tail of attribute
 657  * @payload: length of payload
 658  */
 659 static inline int nla_padlen(int payload)
 660 {
 661         return nla_total_size(payload) - nla_attr_size(payload);
 662 }
 663
 664 /**
 665  * nla_type - attribute type
 666  * @nla: netlink attribute
 667  */
 668 static inline int nla_type(const struct nlattr *nla)
 669 {
 670         return nla->nla_type & NLA_TYPE_MASK;
 671 }
 672
 673 /**
 674  * nla_data - head of payload
 675  * @nla: netlink attribute
 676  */
 677 static inline void *nla_data(const struct nlattr *nla)
 678 {
 679         return (char *) nla + NLA_HDRLEN;
 680 }
 681
 682 /**
 683  * nla_len - length of payload
 684  * @nla: netlink attribute
 685  */
 686 static inline int nla_len(const struct nlattr *nla)
 687 {
 688         return nla->nla_len - NLA_HDRLEN;
 689 }
 690
 691 /**
 692  * nla_ok - check if the netlink attribute fits into the remaining bytes
 693  * @nla: netlink attribute
 694  * @remaining: number of bytes remaining in attribute stream
 695  */
 696 static inline int nla_ok(const struct nlattr *nla, int remaining)
 697 {
 698         return remaining >= (int) sizeof(*nla) &&
 699                nla->nla_len >= sizeof(*nla) &&
 700                nla->nla_len <= remaining;
 701 }
 702
 703 /**
 704  * nla_next - next netlink attribute in attribute stream
 705  * @nla: netlink attribute
 706  * @remaining: number of bytes remaining in attribute stream
 707  *
 708  * Returns the next netlink attribute in the attribute stream and
 709  * decrements remaining by the size of the current attribute.
 710  */
 711 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
 712 {
 713         int totlen = NLA_ALIGN(nla->nla_len);
 714
 715         *remaining -= totlen;
 716         return (struct nlattr *) ((char *) nla + totlen);
 717 }
 718
 719 /**
 720  * nla_find_nested - find attribute in a set of nested attributes
 721  * @nla: attribute containing the nested attributes
 722  * @attrtype: type of attribute to look for
 723  *
 724  * Returns the first attribute which matches the specified type.
 725  */
 726 static inline struct nlattr *
 727 nla_find_nested(const struct nlattr *nla, int attrtype)
 728 {
 729         return nla_find(nla_data(nla), nla_len(nla), attrtype);
 730 }
 731
 732 /**
 733  * nla_parse_nested - parse nested attributes
 734  * @tb: destination array with maxtype+1 elements
 735  * @maxtype: maximum attribute type to be expected
 736  * @nla: attribute containing the nested attributes
 737  * @policy: validation policy
 738  *
 739  * See nla_parse()
 740  */
 741 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
 742                                    const struct nlattr *nla,
 743                                    const struct nla_policy *policy)
 744 {
 745         return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
 746 }
 747
 748 /**
 749  * nla_put_u8 - Add a u8 netlink attribute to a socket buffer
 750  * @skb: socket buffer to add attribute to
 751  * @attrtype: attribute type
 752  * @value: numeric value
 753  */
 754 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
 755 {
 756         return nla_put(skb, attrtype, sizeof(u8), &value);
 757 }
 758
 759 /**
 760  * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
 761  * @skb: socket buffer to add attribute to
 762  * @attrtype: attribute type
 763  * @value: numeric value
 764  */
 765 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
 766 {
 767         return nla_put(skb, attrtype, sizeof(u16), &value);
 768 }
 769
 770 /**
 771  * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer
 772  * @skb: socket buffer to add attribute to
 773  * @attrtype: attribute type
 774  * @value: numeric value
 775  */
 776 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value)
 777 {
 778         return nla_put(skb, attrtype, sizeof(__be16), &value);
 779 }
 780
 781 /**
 782  * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer
 783  * @skb: socket buffer to add attribute to
 784  * @attrtype: attribute type
 785  * @value: numeric value
 786  */
 787 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value)
 788 {
 789         return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, value);
 790 }
 791
 792 /**
 793  * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer
 794  * @skb: socket buffer to add attribute to
 795  * @attrtype: attribute type
 796  * @value: numeric value
 797  */
 798 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value)
 799 {
 800         return nla_put(skb, attrtype, sizeof(__le16), &value);
 801 }
 802
 803 /**
 804  * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
 805  * @skb: socket buffer to add attribute to
 806  * @attrtype: attribute type
 807  * @value: numeric value
 808  */
 809 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
 810 {
 811         return nla_put(skb, attrtype, sizeof(u32), &value);
 812 }
 813
 814 /**
 815  * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
 816  * @skb: socket buffer to add attribute to
 817  * @attrtype: attribute type
 818  * @value: numeric value
 819  */
 820 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value)
 821 {
 822         return nla_put(skb, attrtype, sizeof(__be32), &value);
 823 }
 824
 825 /**
 826  * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer
 827  * @skb: socket buffer to add attribute to
 828  * @attrtype: attribute type
 829  * @value: numeric value
 830  */
 831 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value)
 832 {
 833         return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, value);
 834 }
 835
 836 /**
 837  * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer
 838  * @skb: socket buffer to add attribute to
 839  * @attrtype: attribute type
 840  * @value: numeric value
 841  */
 842 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value)
 843 {
 844         return nla_put(skb, attrtype, sizeof(__le32), &value);
 845 }
 846
 847 /**
 848  * nla_put_u64 - Add a u64 netlink attribute to a socket buffer
 849  * @skb: socket buffer to add attribute to
 850  * @attrtype: attribute type
 851  * @value: numeric value
 852  */
 853 static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
 854 {
 855         return nla_put(skb, attrtype, sizeof(u64), &value);
 856 }
 857
 858 /**
 859  * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer
 860  * @skb: socket buffer to add attribute to
 861  * @attrtype: attribute type
 862  * @value: numeric value
 863  */
 864 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value)
 865 {
 866         return nla_put(skb, attrtype, sizeof(__be64), &value);
 867 }
 868
 869 /**
 870  * nla_put_net64 - Add 64-bit network byte order netlink attribute to a socket buffer
 871  * @skb: socket buffer to add attribute to
 872  * @attrtype: attribute type
 873  * @value: numeric value
 874  */
 875 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value)
 876 {
 877         return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, value);
 878 }
 879
 880 /**
 881  * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer
 882  * @skb: socket buffer to add attribute to
 883  * @attrtype: attribute type
 884  * @value: numeric value
 885  */
 886 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value)
 887 {
 888         return nla_put(skb, attrtype, sizeof(__le64), &value);
 889 }
 890
 891 /**
 892  * nla_put_s8 - Add a s8 netlink attribute to a socket buffer
 893  * @skb: socket buffer to add attribute to
 894  * @attrtype: attribute type
 895  * @value: numeric value
 896  */
 897 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value)
 898 {
 899         return nla_put(skb, attrtype, sizeof(s8), &value);
 900 }
 901
 902 /**
 903  * nla_put_s16 - Add a s16 netlink attribute to a socket buffer
 904  * @skb: socket buffer to add attribute to
 905  * @attrtype: attribute type
 906  * @value: numeric value
 907  */
 908 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value)
 909 {
 910         return nla_put(skb, attrtype, sizeof(s16), &value);
 911 }
 912
 913 /**
 914  * nla_put_s32 - Add a s32 netlink attribute to a socket buffer
 915  * @skb: socket buffer to add attribute to
 916  * @attrtype: attribute type
 917  * @value: numeric value
 918  */
 919 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value)
 920 {
 921         return nla_put(skb, attrtype, sizeof(s32), &value);
 922 }
 923
 924 /**
 925  * nla_put_s64 - Add a s64 netlink attribute to a socket buffer
 926  * @skb: socket buffer to add attribute to
 927  * @attrtype: attribute type
 928  * @value: numeric value
 929  */
 930 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value)
 931 {
 932         return nla_put(skb, attrtype, sizeof(s64), &value);
 933 }
 934
 935 /**
 936  * nla_put_string - Add a string netlink attribute to a socket buffer
 937  * @skb: socket buffer to add attribute to
 938  * @attrtype: attribute type
 939  * @str: NUL terminated string
 940  */
 941 static inline int nla_put_string(struct sk_buff *skb, int attrtype,
 942                                  const char *str)
 943 {
 944         return nla_put(skb, attrtype, strlen(str) + 1, str);
 945 }
 946
 947 /**
 948  * nla_put_flag - Add a flag netlink attribute to a socket buffer
 949  * @skb: socket buffer to add attribute to
 950  * @attrtype: attribute type
 951  */
 952 static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
 953 {
 954         return nla_put(skb, attrtype, 0, NULL);
 955 }
 956
 957 /**
 958  * nla_put_msecs - Add a msecs netlink attribute to a socket buffer
 959  * @skb: socket buffer to add attribute to
 960  * @attrtype: attribute type
 961  * @njiffies: number of jiffies to convert to msecs
 962  */
 963 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
 964                                 unsigned long njiffies)
 965 {
 966         u64 tmp = jiffies_to_msecs(njiffies);
 967         return nla_put(skb, attrtype, sizeof(u64), &tmp);
 968 }
 969
 970 /**
 971  * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket
 972  * buffer
 973  * @skb: socket buffer to add attribute to
 974  * @attrtype: attribute type
 975  * @addr: IPv4 address
 976  */
 977 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype,
 978                                   __be32 addr)
 979 {
 980         return nla_put_be32(skb, attrtype, addr);
 981 }
 982
 983 /**
 984  * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket
 985  * buffer
 986  * @skb: socket buffer to add attribute to
 987  * @attrtype: attribute type
 988  * @addr: IPv6 address
 989  */
 990 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype,
 991                                    const struct in6_addr *addr)
 992 {
 993         return nla_put(skb, attrtype, sizeof(*addr), addr);
 994 }
 995
 996 /**
 997  * nla_get_u32 - return payload of u32 attribute
 998  * @nla: u32 netlink attribute
 999  */
1000 static inline u32 nla_get_u32(const struct nlattr *nla)
1001 {
1002         return *(u32 *) nla_data(nla);
1003 }
1004
1005 /**
1006  * nla_get_be32 - return payload of __be32 attribute
1007  * @nla: __be32 netlink attribute
1008  */
1009 static inline __be32 nla_get_be32(const struct nlattr *nla)
1010 {
1011         return *(__be32 *) nla_data(nla);
1012 }
1013
1014 /**
1015  * nla_get_le32 - return payload of __le32 attribute
1016  * @nla: __le32 netlink attribute
1017  */
1018 static inline __le32 nla_get_le32(const struct nlattr *nla)
1019 {
1020         return *(__le32 *) nla_data(nla);
1021 }
1022
1023 /**
1024  * nla_get_u16 - return payload of u16 attribute
1025  * @nla: u16 netlink attribute
1026  */
1027 static inline u16 nla_get_u16(const struct nlattr *nla)
1028 {
1029         return *(u16 *) nla_data(nla);
1030 }
1031
1032 /**
1033  * nla_get_be16 - return payload of __be16 attribute
1034  * @nla: __be16 netlink attribute
1035  */
1036 static inline __be16 nla_get_be16(const struct nlattr *nla)
1037 {
1038         return *(__be16 *) nla_data(nla);
1039 }
1040
1041 /**
1042  * nla_get_le16 - return payload of __le16 attribute
1043  * @nla: __le16 netlink attribute
1044  */
1045 static inline __le16 nla_get_le16(const struct nlattr *nla)
1046 {
1047         return *(__le16 *) nla_data(nla);
1048 }
1049
1050 /**
1051  * nla_get_u8 - return payload of u8 attribute
1052  * @nla: u8 netlink attribute
1053  */
1054 static inline u8 nla_get_u8(const struct nlattr *nla)
1055 {
1056         return *(u8 *) nla_data(nla);
1057 }
1058
1059 /**
1060  * nla_get_u64 - return payload of u64 attribute
1061  * @nla: u64 netlink attribute
1062  */
1063 static inline u64 nla_get_u64(const struct nlattr *nla)
1064 {
1065         u64 tmp;
1066
1067         nla_memcpy(&tmp, nla, sizeof(tmp));
1068
1069         return tmp;
1070 }
1071
1072 /**
1073  * nla_get_be64 - return payload of __be64 attribute
1074  * @nla: __be64 netlink attribute
1075  */
1076 static inline __be64 nla_get_be64(const struct nlattr *nla)
1077 {
1078         __be64 tmp;
1079
1080         nla_memcpy(&tmp, nla, sizeof(tmp));
1081
1082         return tmp;
1083 }
1084
1085 /**
1086  * nla_get_le64 - return payload of __le64 attribute
1087  * @nla: __le64 netlink attribute
1088  */
1089 static inline __le64 nla_get_le64(const struct nlattr *nla)
1090 {
1091         return *(__le64 *) nla_data(nla);
1092 }
1093
1094 /**
1095  * nla_get_s32 - return payload of s32 attribute
1096  * @nla: s32 netlink attribute
1097  */
1098 static inline s32 nla_get_s32(const struct nlattr *nla)
1099 {
1100         return *(s32 *) nla_data(nla);
1101 }
1102
1103 /**
1104  * nla_get_s16 - return payload of s16 attribute
1105  * @nla: s16 netlink attribute
1106  */
1107 static inline s16 nla_get_s16(const struct nlattr *nla)
1108 {
1109         return *(s16 *) nla_data(nla);
1110 }
1111
1112 /**
1113  * nla_get_s8 - return payload of s8 attribute
1114  * @nla: s8 netlink attribute
1115  */
1116 static inline s8 nla_get_s8(const struct nlattr *nla)
1117 {
1118         return *(s8 *) nla_data(nla);
1119 }
1120
1121 /**
1122  * nla_get_s64 - return payload of s64 attribute
1123  * @nla: s64 netlink attribute
1124  */
1125 static inline s64 nla_get_s64(const struct nlattr *nla)
1126 {
1127         s64 tmp;
1128
1129         nla_memcpy(&tmp, nla, sizeof(tmp));
1130
1131         return tmp;
1132 }
1133
1134 /**
1135  * nla_get_flag - return payload of flag attribute
1136  * @nla: flag netlink attribute
1137  */
1138 static inline int nla_get_flag(const struct nlattr *nla)
1139 {
1140         return !!nla;
1141 }
1142
1143 /**
1144  * nla_get_msecs - return payload of msecs attribute
1145  * @nla: msecs netlink attribute
1146  *
1147  * Returns the number of milliseconds in jiffies.
1148  */
1149 static inline unsigned long nla_get_msecs(const struct nlattr *nla)
1150 {
1151         u64 msecs = nla_get_u64(nla);
1152
1153         return msecs_to_jiffies((unsigned long) msecs);
1154 }
1155
1156 /**
1157  * nla_get_in_addr - return payload of IPv4 address attribute
1158  * @nla: IPv4 address netlink attribute
1159  */
1160 static inline __be32 nla_get_in_addr(const struct nlattr *nla)
1161 {
1162         return *(__be32 *) nla_data(nla);
1163 }
1164
1165 /**
1166  * nla_get_in6_addr - return payload of IPv6 address attribute
1167  * @nla: IPv6 address netlink attribute
1168  */
1169 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla)
1170 {
1171         struct in6_addr tmp;
1172
1173         nla_memcpy(&tmp, nla, sizeof(tmp));
1174         return tmp;
1175 }
1176
1177 /**
1178  * nla_nest_start - Start a new level of nested attributes
1179  * @skb: socket buffer to add attributes to
1180  * @attrtype: attribute type of container
1181  *
1182  * Returns the container attribute
1183  */
1184 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
1185 {
1186         struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
1187
1188         if (nla_put(skb, attrtype, 0, NULL) < 0)
1189                 return NULL;
1190
1191         return start;
1192 }
1193
1194 /**
1195  * nla_nest_end - Finalize nesting of attributes
1196  * @skb: socket buffer the attributes are stored in
1197  * @start: container attribute
1198  *
1199  * Corrects the container attribute header to include the all
1200  * appeneded attributes.
1201  *
1202  * Returns the total data length of the skb.
1203  */
1204 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1205 {
1206         start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
1207         return skb->len;
1208 }
1209
1210 /**
1211  * nla_nest_cancel - Cancel nesting of attributes
1212  * @skb: socket buffer the message is stored in
1213  * @start: container attribute
1214  *
1215  * Removes the container attribute and including all nested
1216  * attributes. Returns -EMSGSIZE
1217  */
1218 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
1219 {
1220         nlmsg_trim(skb, start);
1221 }
1222
1223 /**
1224  * nla_validate_nested - Validate a stream of nested attributes
1225  * @start: container attribute
1226  * @maxtype: maximum attribute type to be expected
1227  * @policy: validation policy
1228  *
1229  * Validates all attributes in the nested attribute stream against the
1230  * specified policy. Attributes with a type exceeding maxtype will be
1231  * ignored. See documenation of struct nla_policy for more details.
1232  *
1233  * Returns 0 on success or a negative error code.
1234  */
1235 static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
1236                                       const struct nla_policy *policy)
1237 {
1238         return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
1239 }
1240
1241 /**
1242  * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
1243  * @skb: socket buffer the message is stored in
1244  *
1245  * Return true if padding is needed to align the next attribute (nla_data()) to
1246  * a 64-bit aligned area.
1247  */
1248 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
1249 {
1250 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1251         /* The nlattr header is 4 bytes in size, that's why we test
1252          * if the skb->data _is_ aligned.  A NOP attribute, plus
1253          * nlattr header for next attribute, will make nla_data()
1254          * 8-byte aligned.
1255          */
1256         if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
1257                 return true;
1258 #endif
1259         return false;
1260 }
1261
1262 /**
1263  * nla_align_64bit - 64-bit align the nla_data() of next attribute
1264  * @skb: socket buffer the message is stored in
1265  * @padattr: attribute type for the padding
1266  *
1267  * Conditionally emit a padding netlink attribute in order to make
1268  * the next attribute we emit have a 64-bit aligned nla_data() area.
1269  * This will only be done in architectures which do not have
1270  * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined.
1271  *
1272  * Returns zero on success or a negative error code.
1273  */
1274 static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
1275 {
1276         if (nla_need_padding_for_64bit(skb) &&
1277             !nla_reserve(skb, padattr, 0))
1278                 return -EMSGSIZE;
1279
1280         return 0;
1281 }
1282
1283 /**
1284  * nla_total_size_64bit - total length of attribute including padding
1285  * @payload: length of payload
1286  */
1287 static inline int nla_total_size_64bit(int payload)
1288 {
1289         return NLA_ALIGN(nla_attr_size(payload))
1290 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1291                 + NLA_ALIGN(nla_attr_size(0))
1292 #endif
1293                 ;
1294 }
1295
1296 /**
1297  * nla_for_each_attr - iterate over a stream of attributes
1298  * @pos: loop counter, set to current attribute
1299  * @head: head of attribute stream
1300  * @len: length of attribute stream
1301  * @rem: initialized to len, holds bytes currently remaining in stream
1302  */
1303 #define nla_for_each_attr(pos, head, len, rem) \
1304         for (pos = head, rem = len; \
1305              nla_ok(pos, rem); \
1306              pos = nla_next(pos, &(rem)))
1307
1308 /**
1309  * nla_for_each_nested - iterate over nested attributes
1310  * @pos: loop counter, set to current attribute
1311  * @nla: attribute containing the nested attributes
1312  * @rem: initialized to len, holds bytes currently remaining in stream
1313  */
1314 #define nla_for_each_nested(pos, nla, rem) \
1315         nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
1316
1317 /**
1318  * nla_is_last - Test if attribute is last in stream
1319  * @nla: attribute to test
1320  * @rem: bytes remaining in stream
1321  */
1322 static inline bool nla_is_last(const struct nlattr *nla, int rem)
1323 {
1324         return nla->nla_len == rem;
1325 }
1326
1327 #endif