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_string(skb, type, str) add string attribute to skb 102 * nla_put_flag(skb, type) add flag attribute to skb 103 * nla_put_msecs(skb, type, jiffies) add msecs attribute to skb 104 * 105 * Exceptions Based Attribute Construction: 106 * NLA_PUT(skb, type, len, data) add attribute to skb 107 * NLA_PUT_U8(skb, type, value) add u8 attribute to skb 108 * NLA_PUT_U16(skb, type, value) add u16 attribute to skb 109 * NLA_PUT_U32(skb, type, value) add u32 attribute to skb 110 * NLA_PUT_U64(skb, type, value) add u64 attribute to skb 111 * NLA_PUT_STRING(skb, type, str) add string attribute to skb 112 * NLA_PUT_FLAG(skb, type) add flag attribute to skb 113 * NLA_PUT_MSECS(skb, type, jiffies) add msecs attribute to skb 114 * 115 * The meaning of these functions is equal to their lower case 116 * variants but they jump to the label nla_put_failure in case 117 * of a failure. 118 * 119 * Nested Attributes Construction: 120 * nla_nest_start(skb, type) start a nested attribute 121 * nla_nest_end(skb, nla) finalize a nested attribute 122 * nla_nest_cancel(skb, nla) cancel nested attribute construction 123 * 124 * Attribute Length Calculations: 125 * nla_attr_size(payload) length of attribute w/o padding 126 * nla_total_size(payload) length of attribute w/ padding 127 * nla_padlen(payload) length of padding 128 * 129 * Attribute Payload Access: 130 * nla_data(nla) head of attribute payload 131 * nla_len(nla) length of attribute payload 132 * 133 * Attribute Payload Access for Basic Types: 134 * nla_get_u8(nla) get payload for a u8 attribute 135 * nla_get_u16(nla) get payload for a u16 attribute 136 * nla_get_u32(nla) get payload for a u32 attribute 137 * nla_get_u64(nla) get payload for a u64 attribute 138 * nla_get_flag(nla) return 1 if flag is true 139 * nla_get_msecs(nla) get payload for a msecs attribute 140 * 141 * Attribute Misc: 142 * nla_memcpy(dest, nla, count) copy attribute into memory 143 * nla_memcmp(nla, data, size) compare attribute with memory area 144 * nla_strlcpy(dst, nla, size) copy attribute to a sized string 145 * nla_strcmp(nla, str) compare attribute with string 146 * 147 * Attribute Parsing: 148 * nla_ok(nla, remaining) does nla fit into remaining bytes? 149 * nla_next(nla, remaining) get next netlink attribute 150 * nla_validate() validate a stream of attributes 151 * nla_validate_nested() validate a stream of nested attributes 152 * nla_find() find attribute in stream of attributes 153 * nla_find_nested() find attribute in nested attributes 154 * nla_parse() parse and validate stream of attrs 155 * nla_parse_nested() parse nested attribuets 156 * nla_for_each_attr() loop over all attributes 157 * nla_for_each_nested() loop over the nested attributes 158 *========================================================================= 159 */ 160 161 /** 162 * Standard attribute types to specify validation policy 163 */ 164enum { 165 NLA_UNSPEC, 166 NLA_U8, 167 NLA_U16, 168 NLA_U32, 169 NLA_U64, 170 NLA_STRING, 171 NLA_FLAG, 172 NLA_MSECS, 173 NLA_NESTED, 174 NLA_NESTED_COMPAT, 175 NLA_NUL_STRING, 176 NLA_BINARY, 177 __NLA_TYPE_MAX, 178}; 179 180#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) 181 182/** 183 * struct nla_policy - attribute validation policy 184 * @type: Type of attribute or NLA_UNSPEC 185 * @len: Type specific length of payload 186 * 187 * Policies are defined as arrays of this struct, the array must be 188 * accessible by attribute type up to the highest identifier to be expected. 189 * 190 * Meaning of `len' field: 191 * NLA_STRING Maximum length of string 192 * NLA_NUL_STRING Maximum length of string (excluding NUL) 193 * NLA_FLAG Unused 194 * NLA_BINARY Maximum length of attribute payload 195 * NLA_NESTED_COMPAT Exact length of structure payload 196 * All other Exact length of attribute payload 197 * 198 * Example: 199 * static const struct nla_policy my_policy[ATTR_MAX+1] = { 200 * [ATTR_FOO] = { .type = NLA_U16 }, 201 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, 202 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) }, 203 * }; 204 */ 205struct nla_policy { 206 u16 type; 207 u16 len; 208}; 209 210/** 211 * struct nl_info - netlink source information 212 * @nlh: Netlink message header of original request 213 * @pid: Netlink PID of requesting application 214 */ 215struct nl_info { 216 struct nlmsghdr *nlh; 217 struct net *nl_net; 218 u32 pid; 219}; 220 221extern int netlink_rcv_skb(struct sk_buff *skb, 222 int (*cb)(struct sk_buff *, 223 struct nlmsghdr *)); 224extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb, 225 u32 pid, unsigned int group, int report, 226 gfp_t flags); 227 228extern int nla_validate(struct nlattr *head, int len, int maxtype, 229 const struct nla_policy *policy); 230extern int nla_parse(struct nlattr *tb[], int maxtype, 231 struct nlattr *head, int len, 232 const struct nla_policy *policy); 233extern int nla_policy_len(const struct nla_policy *, int); 234extern struct nlattr * nla_find(struct nlattr *head, int len, int attrtype); 235extern size_t nla_strlcpy(char *dst, const struct nlattr *nla, 236 size_t dstsize); 237extern int nla_memcpy(void *dest, const struct nlattr *src, int count); 238extern int nla_memcmp(const struct nlattr *nla, const void *data, 239 size_t size); 240extern int nla_strcmp(const struct nlattr *nla, const char *str); 241extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype, 242 int attrlen); 243extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 244extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype, 245 int attrlen); 246extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 247extern void __nla_put(struct sk_buff *skb, int attrtype, 248 int attrlen, const void *data); 249extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen, 250 const void *data); 251extern int nla_put(struct sk_buff *skb, int attrtype, 252 int attrlen, const void *data); 253extern int nla_put_nohdr(struct sk_buff *skb, int attrlen, 254 const void *data); 255extern int nla_append(struct sk_buff *skb, int attrlen, 256 const void *data); 257 258/************************************************************************** 259 * Netlink Messages 260 **************************************************************************/ 261 262/** 263 * nlmsg_msg_size - length of netlink message not including padding 264 * @payload: length of message payload 265 */ 266static inline int nlmsg_msg_size(int payload) 267{ 268 return NLMSG_HDRLEN + payload; 269} 270 271/** 272 * nlmsg_total_size - length of netlink message including padding 273 * @payload: length of message payload 274 */ 275static inline int nlmsg_total_size(int payload) 276{ 277 return NLMSG_ALIGN(nlmsg_msg_size(payload)); 278} 279 280/** 281 * nlmsg_padlen - length of padding at the message's tail 282 * @payload: length of message payload 283 */ 284static inline int nlmsg_padlen(int payload) 285{ 286 return nlmsg_total_size(payload) - nlmsg_msg_size(payload); 287} 288 289/** 290 * nlmsg_data - head of message payload 291 * @nlh: netlink messsage header 292 */ 293static inline void *nlmsg_data(const struct nlmsghdr *nlh) 294{ 295 return (unsigned char *) nlh + NLMSG_HDRLEN; 296} 297 298/** 299 * nlmsg_len - length of message payload 300 * @nlh: netlink message header 301 */ 302static inline int nlmsg_len(const struct nlmsghdr *nlh) 303{ 304 return nlh->nlmsg_len - NLMSG_HDRLEN; 305} 306 307/** 308 * nlmsg_attrdata - head of attributes data 309 * @nlh: netlink message header 310 * @hdrlen: length of family specific header 311 */ 312static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 313 int hdrlen) 314{ 315 unsigned char *data = nlmsg_data(nlh); 316 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); 317} 318 319/** 320 * nlmsg_attrlen - length of attributes data 321 * @nlh: netlink message header 322 * @hdrlen: length of family specific header 323 */ 324static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) 325{ 326 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); 327} 328 329/** 330 * nlmsg_ok - check if the netlink message fits into the remaining bytes 331 * @nlh: netlink message header 332 * @remaining: number of bytes remaining in message stream 333 */ 334static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) 335{ 336 return (remaining >= (int) sizeof(struct nlmsghdr) && 337 nlh->nlmsg_len >= sizeof(struct nlmsghdr) && 338 nlh->nlmsg_len <= remaining); 339} 340 341/** 342 * nlmsg_next - next netlink message in message stream 343 * @nlh: netlink message header 344 * @remaining: number of bytes remaining in message stream 345 * 346 * Returns the next netlink message in the message stream and 347 * decrements remaining by the size of the current message. 348 */ 349static inline struct nlmsghdr *nlmsg_next(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(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(struct nlmsghdr *nlh, int hdrlen, int maxtype, 402 const struct nla_policy *policy) 403{ 404 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 405 return -EINVAL; 406 407 return nla_validate(nlmsg_attrdata(nlh, hdrlen), 408 nlmsg_attrlen(nlh, hdrlen), maxtype, policy); 409} 410 411/** 412 * nlmsg_report - need to report back to application? 413 * @nlh: netlink message header 414 * 415 * Returns 1 if a report back to the application is requested. 416 */ 417static inline int nlmsg_report(const struct nlmsghdr *nlh) 418{ 419 return !!(nlh->nlmsg_flags & NLM_F_ECHO); 420} 421 422/** 423 * nlmsg_for_each_attr - iterate over a stream of attributes 424 * @pos: loop counter, set to current attribute 425 * @nlh: netlink message header 426 * @hdrlen: length of familiy specific header 427 * @rem: initialized to len, holds bytes currently remaining in stream 428 */ 429#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ 430 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ 431 nlmsg_attrlen(nlh, hdrlen), rem) 432 433 434/** 435 * nlmsg_put - Add a new netlink message to an skb 436 * @skb: socket buffer to store message in 437 * @pid: netlink process id 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 pid, 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, pid, 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).pid, 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 * 497 * Returns the total data length of the skb. 498 */ 499static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 500{ 501 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 502 503 return skb->len; 504} 505 506/** 507 * nlmsg_get_pos - return current position in netlink message 508 * @skb: socket buffer the message is stored in 509 * 510 * Returns a pointer to the current tail of the message. 511 */ 512static inline void *nlmsg_get_pos(struct sk_buff *skb) 513{ 514 return skb_tail_pointer(skb); 515} 516 517/** 518 * nlmsg_trim - Trim message to a mark 519 * @skb: socket buffer the message is stored in 520 * @mark: mark to trim to 521 * 522 * Trims the message to the provided mark. 523 */ 524static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 525{ 526 if (mark) 527 skb_trim(skb, (unsigned char *) mark - skb->data); 528} 529 530/** 531 * nlmsg_cancel - Cancel construction of a netlink message 532 * @skb: socket buffer the message is stored in 533 * @nlh: netlink message header 534 * 535 * Removes the complete netlink message including all 536 * attributes from the socket buffer again. 537 */ 538static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 539{ 540 nlmsg_trim(skb, nlh); 541} 542 543/** 544 * nlmsg_free - free a netlink message 545 * @skb: socket buffer of netlink message 546 */ 547static inline void nlmsg_free(struct sk_buff *skb) 548{ 549 kfree_skb(skb); 550} 551 552/** 553 * nlmsg_multicast - multicast a netlink message 554 * @sk: netlink socket to spread messages to 555 * @skb: netlink message as socket buffer 556 * @pid: own netlink pid to avoid sending to yourself 557 * @group: multicast group id 558 * @flags: allocation flags 559 */ 560static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 561 u32 pid, unsigned int group, gfp_t flags) 562{ 563 int err; 564 565 NETLINK_CB(skb).dst_group = group; 566 567 err = netlink_broadcast(sk, skb, pid, group, flags); 568 if (err > 0) 569 err = 0; 570 571 return err; 572} 573 574/** 575 * nlmsg_unicast - unicast a netlink message 576 * @sk: netlink socket to spread message to 577 * @skb: netlink message as socket buffer 578 * @pid: netlink pid of the destination socket 579 */ 580static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid) 581{ 582 int err; 583 584 err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT); 585 if (err > 0) 586 err = 0; 587 588 return err; 589} 590 591/** 592 * nlmsg_for_each_msg - iterate over a stream of messages 593 * @pos: loop counter, set to current message 594 * @head: head of message stream 595 * @len: length of message stream 596 * @rem: initialized to len, holds bytes currently remaining in stream 597 */ 598#define nlmsg_for_each_msg(pos, head, len, rem) \ 599 for (pos = head, rem = len; \ 600 nlmsg_ok(pos, rem); \ 601 pos = nlmsg_next(pos, &(rem))) 602 603/************************************************************************** 604 * Netlink Attributes 605 **************************************************************************/ 606 607/** 608 * nla_attr_size - length of attribute not including padding 609 * @payload: length of payload 610 */ 611static inline int nla_attr_size(int payload) 612{ 613 return NLA_HDRLEN + payload; 614} 615 616/** 617 * nla_total_size - total length of attribute including padding 618 * @payload: length of payload 619 */ 620static inline int nla_total_size(int payload) 621{ 622 return NLA_ALIGN(nla_attr_size(payload)); 623} 624 625/** 626 * nla_padlen - length of padding at the tail of attribute 627 * @payload: length of payload 628 */ 629static inline int nla_padlen(int payload) 630{ 631 return nla_total_size(payload) - nla_attr_size(payload); 632} 633 634/** 635 * nla_type - attribute type 636 * @nla: netlink attribute 637 */ 638static inline int nla_type(const struct nlattr *nla) 639{ 640 return nla->nla_type & NLA_TYPE_MASK; 641} 642 643/** 644 * nla_data - head of payload 645 * @nla: netlink attribute 646 */ 647static inline void *nla_data(const struct nlattr *nla) 648{ 649 return (char *) nla + NLA_HDRLEN; 650} 651 652/** 653 * nla_len - length of payload 654 * @nla: netlink attribute 655 */ 656static inline int nla_len(const struct nlattr *nla) 657{ 658 return nla->nla_len - NLA_HDRLEN; 659} 660 661/** 662 * nla_ok - check if the netlink attribute fits into the remaining bytes 663 * @nla: netlink attribute 664 * @remaining: number of bytes remaining in attribute stream 665 */ 666static inline int nla_ok(const struct nlattr *nla, int remaining) 667{ 668 return remaining >= (int) sizeof(*nla) && 669 nla->nla_len >= sizeof(*nla) && 670 nla->nla_len <= remaining; 671} 672 673/** 674 * nla_next - next netlink attribute in attribute stream 675 * @nla: netlink attribute 676 * @remaining: number of bytes remaining in attribute stream 677 * 678 * Returns the next netlink attribute in the attribute stream and 679 * decrements remaining by the size of the current attribute. 680 */ 681static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 682{ 683 int totlen = NLA_ALIGN(nla->nla_len); 684 685 *remaining -= totlen; 686 return (struct nlattr *) ((char *) nla + totlen); 687} 688 689/** 690 * nla_find_nested - find attribute in a set of nested attributes 691 * @nla: attribute containing the nested attributes 692 * @attrtype: type of attribute to look for 693 * 694 * Returns the first attribute which matches the specified type. 695 */ 696static inline struct nlattr *nla_find_nested(struct nlattr *nla, int attrtype) 697{ 698 return nla_find(nla_data(nla), nla_len(nla), attrtype); 699} 700 701/** 702 * nla_parse_nested - parse nested attributes 703 * @tb: destination array with maxtype+1 elements 704 * @maxtype: maximum attribute type to be expected 705 * @nla: attribute containing the nested attributes 706 * @policy: validation policy 707 * 708 * See nla_parse() 709 */ 710static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 711 const struct nlattr *nla, 712 const struct nla_policy *policy) 713{ 714 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); 715} 716 717/** 718 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 719 * @skb: socket buffer to add attribute to 720 * @attrtype: attribute type 721 * @value: numeric value 722 */ 723static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 724{ 725 return nla_put(skb, attrtype, sizeof(u8), &value); 726} 727 728/** 729 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer 730 * @skb: socket buffer to add attribute to 731 * @attrtype: attribute type 732 * @value: numeric value 733 */ 734static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) 735{ 736 return nla_put(skb, attrtype, sizeof(u16), &value); 737} 738 739/** 740 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 741 * @skb: socket buffer to add attribute to 742 * @attrtype: attribute type 743 * @value: numeric value 744 */ 745static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 746{ 747 return nla_put(skb, attrtype, sizeof(u32), &value); 748} 749 750/** 751 * nla_put_64 - Add a u64 netlink attribute to a socket buffer 752 * @skb: socket buffer to add attribute to 753 * @attrtype: attribute type 754 * @value: numeric value 755 */ 756static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value) 757{ 758 return nla_put(skb, attrtype, sizeof(u64), &value); 759} 760 761/** 762 * nla_put_string - Add a string netlink attribute to a socket buffer 763 * @skb: socket buffer to add attribute to 764 * @attrtype: attribute type 765 * @str: NUL terminated string 766 */ 767static inline int nla_put_string(struct sk_buff *skb, int attrtype, 768 const char *str) 769{ 770 return nla_put(skb, attrtype, strlen(str) + 1, str); 771} 772 773/** 774 * nla_put_flag - Add a flag netlink attribute to a socket buffer 775 * @skb: socket buffer to add attribute to 776 * @attrtype: attribute type 777 */ 778static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 779{ 780 return nla_put(skb, attrtype, 0, NULL); 781} 782 783/** 784 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer 785 * @skb: socket buffer to add attribute to 786 * @attrtype: attribute type 787 * @jiffies: number of msecs in jiffies 788 */ 789static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 790 unsigned long jiffies) 791{ 792 u64 tmp = jiffies_to_msecs(jiffies); 793 return nla_put(skb, attrtype, sizeof(u64), &tmp); 794} 795 796#define NLA_PUT(skb, attrtype, attrlen, data) \ 797 do { \ 798 if (unlikely(nla_put(skb, attrtype, attrlen, data) < 0)) \ 799 goto nla_put_failure; \ 800 } while(0) 801 802#define NLA_PUT_TYPE(skb, type, attrtype, value) \ 803 do { \ 804 type __tmp = value; \ 805 NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \ 806 } while(0) 807 808#define NLA_PUT_U8(skb, attrtype, value) \ 809 NLA_PUT_TYPE(skb, u8, attrtype, value) 810 811#define NLA_PUT_U16(skb, attrtype, value) \ 812 NLA_PUT_TYPE(skb, u16, attrtype, value) 813 814#define NLA_PUT_LE16(skb, attrtype, value) \ 815 NLA_PUT_TYPE(skb, __le16, attrtype, value) 816 817#define NLA_PUT_BE16(skb, attrtype, value) \ 818 NLA_PUT_TYPE(skb, __be16, attrtype, value) 819 820#define NLA_PUT_U32(skb, attrtype, value) \ 821 NLA_PUT_TYPE(skb, u32, attrtype, value) 822 823#define NLA_PUT_BE32(skb, attrtype, value) \ 824 NLA_PUT_TYPE(skb, __be32, attrtype, value) 825 826#define NLA_PUT_U64(skb, attrtype, value) \ 827 NLA_PUT_TYPE(skb, u64, attrtype, value) 828 829#define NLA_PUT_BE64(skb, attrtype, value) \ 830 NLA_PUT_TYPE(skb, __be64, attrtype, value) 831 832#define NLA_PUT_STRING(skb, attrtype, value) \ 833 NLA_PUT(skb, attrtype, strlen(value) + 1, value) 834 835#define NLA_PUT_FLAG(skb, attrtype) \ 836 NLA_PUT(skb, attrtype, 0, NULL) 837 838#define NLA_PUT_MSECS(skb, attrtype, jiffies) \ 839 NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies)) 840 841/** 842 * nla_get_u32 - return payload of u32 attribute 843 * @nla: u32 netlink attribute 844 */ 845static inline u32 nla_get_u32(const struct nlattr *nla) 846{ 847 return *(u32 *) nla_data(nla); 848} 849 850/** 851 * nla_get_be32 - return payload of __be32 attribute 852 * @nla: __be32 netlink attribute 853 */ 854static inline __be32 nla_get_be32(const struct nlattr *nla) 855{ 856 return *(__be32 *) nla_data(nla); 857} 858 859/** 860 * nla_get_u16 - return payload of u16 attribute 861 * @nla: u16 netlink attribute 862 */ 863static inline u16 nla_get_u16(const struct nlattr *nla) 864{ 865 return *(u16 *) nla_data(nla); 866} 867 868/** 869 * nla_get_be16 - return payload of __be16 attribute 870 * @nla: __be16 netlink attribute 871 */ 872static inline __be16 nla_get_be16(const struct nlattr *nla) 873{ 874 return *(__be16 *) nla_data(nla); 875} 876 877/** 878 * nla_get_le16 - return payload of __le16 attribute 879 * @nla: __le16 netlink attribute 880 */ 881static inline __le16 nla_get_le16(const struct nlattr *nla) 882{ 883 return *(__le16 *) nla_data(nla); 884} 885 886/** 887 * nla_get_u8 - return payload of u8 attribute 888 * @nla: u8 netlink attribute 889 */ 890static inline u8 nla_get_u8(const struct nlattr *nla) 891{ 892 return *(u8 *) nla_data(nla); 893} 894 895/** 896 * nla_get_u64 - return payload of u64 attribute 897 * @nla: u64 netlink attribute 898 */ 899static inline u64 nla_get_u64(const struct nlattr *nla) 900{ 901 u64 tmp; 902 903 nla_memcpy(&tmp, nla, sizeof(tmp)); 904 905 return tmp; 906} 907 908/** 909 * nla_get_be64 - return payload of __be64 attribute 910 * @nla: __be64 netlink attribute 911 */ 912static inline __be64 nla_get_be64(const struct nlattr *nla) 913{ 914 __be64 tmp; 915 916 nla_memcpy(&tmp, nla, sizeof(tmp)); 917 918 return tmp; 919} 920 921/** 922 * nla_get_flag - return payload of flag attribute 923 * @nla: flag netlink attribute 924 */ 925static inline int nla_get_flag(const struct nlattr *nla) 926{ 927 return !!nla; 928} 929 930/** 931 * nla_get_msecs - return payload of msecs attribute 932 * @nla: msecs netlink attribute 933 * 934 * Returns the number of milliseconds in jiffies. 935 */ 936static inline unsigned long nla_get_msecs(const struct nlattr *nla) 937{ 938 u64 msecs = nla_get_u64(nla); 939 940 return msecs_to_jiffies((unsigned long) msecs); 941} 942 943/** 944 * nla_nest_start - Start a new level of nested attributes 945 * @skb: socket buffer to add attributes to 946 * @attrtype: attribute type of container 947 * 948 * Returns the container attribute 949 */ 950static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 951{ 952 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 953 954 if (nla_put(skb, attrtype, 0, NULL) < 0) 955 return NULL; 956 957 return start; 958} 959 960/** 961 * nla_nest_end - Finalize nesting of attributes 962 * @skb: socket buffer the attributes are stored in 963 * @start: container attribute 964 * 965 * Corrects the container attribute header to include the all 966 * appeneded attributes. 967 * 968 * Returns the total data length of the skb. 969 */ 970static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 971{ 972 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 973 return skb->len; 974} 975 976/** 977 * nla_nest_cancel - Cancel nesting of attributes 978 * @skb: socket buffer the message is stored in 979 * @start: container attribute 980 * 981 * Removes the container attribute and including all nested 982 * attributes. Returns -EMSGSIZE 983 */ 984static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 985{ 986 nlmsg_trim(skb, start); 987} 988 989/** 990 * nla_validate_nested - Validate a stream of nested attributes 991 * @start: container attribute 992 * @maxtype: maximum attribute type to be expected 993 * @policy: validation policy 994 * 995 * Validates all attributes in the nested attribute stream against the 996 * specified policy. Attributes with a type exceeding maxtype will be 997 * ignored. See documenation of struct nla_policy for more details. 998 * 999 * Returns 0 on success or a negative error code. 1000 */ 1001static inline int nla_validate_nested(struct nlattr *start, int maxtype, 1002 const struct nla_policy *policy) 1003{ 1004 return nla_validate(nla_data(start), nla_len(start), maxtype, policy); 1005} 1006 1007/** 1008 * nla_for_each_attr - iterate over a stream of attributes 1009 * @pos: loop counter, set to current attribute 1010 * @head: head of attribute stream 1011 * @len: length of attribute stream 1012 * @rem: initialized to len, holds bytes currently remaining in stream 1013 */ 1014#define nla_for_each_attr(pos, head, len, rem) \ 1015 for (pos = head, rem = len; \ 1016 nla_ok(pos, rem); \ 1017 pos = nla_next(pos, &(rem))) 1018 1019/** 1020 * nla_for_each_nested - iterate over nested attributes 1021 * @pos: loop counter, set to current attribute 1022 * @nla: attribute containing the nested attributes 1023 * @rem: initialized to len, holds bytes currently remaining in stream 1024 */ 1025#define nla_for_each_nested(pos, nla, rem) \ 1026 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 1027 1028#endif 1029