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