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() finanlize 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 struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = { 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#if 0 434/* FIXME: Enable once all users have been converted */ 435 436/** 437 * __nlmsg_put - Add a new netlink message to an skb 438 * @skb: socket buffer to store message in 439 * @pid: netlink process id 440 * @seq: sequence number of message 441 * @type: message type 442 * @payload: length of message payload 443 * @flags: message flags 444 * 445 * The caller is responsible to ensure that the skb provides enough 446 * tailroom for both the netlink header and payload. 447 */ 448static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid, 449 u32 seq, int type, int payload, 450 int flags) 451{ 452 struct nlmsghdr *nlh; 453 454 nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload)); 455 nlh->nlmsg_type = type; 456 nlh->nlmsg_len = nlmsg_msg_size(payload); 457 nlh->nlmsg_flags = flags; 458 nlh->nlmsg_pid = pid; 459 nlh->nlmsg_seq = seq; 460 461 memset((unsigned char *) nlmsg_data(nlh) + payload, 0, 462 nlmsg_padlen(payload)); 463 464 return nlh; 465} 466#endif 467 468/** 469 * nlmsg_put - Add a new netlink message to an skb 470 * @skb: socket buffer to store message in 471 * @pid: netlink process id 472 * @seq: sequence number of message 473 * @type: message type 474 * @payload: length of message payload 475 * @flags: message flags 476 * 477 * Returns NULL if the tailroom of the skb is insufficient to store 478 * the message header and payload. 479 */ 480static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, 481 int type, int payload, int flags) 482{ 483 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) 484 return NULL; 485 486 return __nlmsg_put(skb, pid, seq, type, payload, flags); 487} 488 489/** 490 * nlmsg_put_answer - Add a new callback based netlink message to an skb 491 * @skb: socket buffer to store message in 492 * @cb: netlink callback 493 * @type: message type 494 * @payload: length of message payload 495 * @flags: message flags 496 * 497 * Returns NULL if the tailroom of the skb is insufficient to store 498 * the message header and payload. 499 */ 500static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, 501 struct netlink_callback *cb, 502 int type, int payload, 503 int flags) 504{ 505 return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, 506 type, payload, flags); 507} 508 509/** 510 * nlmsg_new - Allocate a new netlink message 511 * @payload: size of the message payload 512 * @flags: the type of memory to allocate. 513 * 514 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known 515 * and a good default is needed. 516 */ 517static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) 518{ 519 return alloc_skb(nlmsg_total_size(payload), flags); 520} 521 522/** 523 * nlmsg_end - Finalize a netlink message 524 * @skb: socket buffer the message is stored in 525 * @nlh: netlink message header 526 * 527 * Corrects the netlink message header to include the appeneded 528 * attributes. Only necessary if attributes have been added to 529 * the message. 530 * 531 * Returns the total data length of the skb. 532 */ 533static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 534{ 535 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 536 537 return skb->len; 538} 539 540/** 541 * nlmsg_get_pos - return current position in netlink message 542 * @skb: socket buffer the message is stored in 543 * 544 * Returns a pointer to the current tail of the message. 545 */ 546static inline void *nlmsg_get_pos(struct sk_buff *skb) 547{ 548 return skb_tail_pointer(skb); 549} 550 551/** 552 * nlmsg_trim - Trim message to a mark 553 * @skb: socket buffer the message is stored in 554 * @mark: mark to trim to 555 * 556 * Trims the message to the provided mark. 557 */ 558static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 559{ 560 if (mark) 561 skb_trim(skb, (unsigned char *) mark - skb->data); 562} 563 564/** 565 * nlmsg_cancel - Cancel construction of a netlink message 566 * @skb: socket buffer the message is stored in 567 * @nlh: netlink message header 568 * 569 * Removes the complete netlink message including all 570 * attributes from the socket buffer again. 571 */ 572static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 573{ 574 nlmsg_trim(skb, nlh); 575} 576 577/** 578 * nlmsg_free - free a netlink message 579 * @skb: socket buffer of netlink message 580 */ 581static inline void nlmsg_free(struct sk_buff *skb) 582{ 583 kfree_skb(skb); 584} 585 586/** 587 * nlmsg_multicast - multicast a netlink message 588 * @sk: netlink socket to spread messages to 589 * @skb: netlink message as socket buffer 590 * @pid: own netlink pid to avoid sending to yourself 591 * @group: multicast group id 592 * @flags: allocation flags 593 */ 594static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 595 u32 pid, unsigned int group, gfp_t flags) 596{ 597 int err; 598 599 NETLINK_CB(skb).dst_group = group; 600 601 err = netlink_broadcast(sk, skb, pid, group, flags); 602 if (err > 0) 603 err = 0; 604 605 return err; 606} 607 608/** 609 * nlmsg_unicast - unicast a netlink message 610 * @sk: netlink socket to spread message to 611 * @skb: netlink message as socket buffer 612 * @pid: netlink pid of the destination socket 613 */ 614static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid) 615{ 616 int err; 617 618 err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT); 619 if (err > 0) 620 err = 0; 621 622 return err; 623} 624 625/** 626 * nlmsg_for_each_msg - iterate over a stream of messages 627 * @pos: loop counter, set to current message 628 * @head: head of message stream 629 * @len: length of message stream 630 * @rem: initialized to len, holds bytes currently remaining in stream 631 */ 632#define nlmsg_for_each_msg(pos, head, len, rem) \ 633 for (pos = head, rem = len; \ 634 nlmsg_ok(pos, rem); \ 635 pos = nlmsg_next(pos, &(rem))) 636 637/************************************************************************** 638 * Netlink Attributes 639 **************************************************************************/ 640 641/** 642 * nla_attr_size - length of attribute not including padding 643 * @payload: length of payload 644 */ 645static 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 */ 654static 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 */ 663static 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 */ 672static 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 */ 681static 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 */ 690static 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 */ 700static 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 */ 715static 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 */ 730static inline struct nlattr *nla_find_nested(struct nlattr *nla, int attrtype) 731{ 732 return nla_find(nla_data(nla), nla_len(nla), attrtype); 733} 734 735/** 736 * nla_parse_nested - parse nested attributes 737 * @tb: destination array with maxtype+1 elements 738 * @maxtype: maximum attribute type to be expected 739 * @nla: attribute containing the nested attributes 740 * @policy: validation policy 741 * 742 * See nla_parse() 743 */ 744static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 745 const struct nlattr *nla, 746 const struct nla_policy *policy) 747{ 748 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); 749} 750 751/** 752 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 753 * @skb: socket buffer to add attribute to 754 * @attrtype: attribute type 755 * @value: numeric value 756 */ 757static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 758{ 759 return nla_put(skb, attrtype, sizeof(u8), &value); 760} 761 762/** 763 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer 764 * @skb: socket buffer to add attribute to 765 * @attrtype: attribute type 766 * @value: numeric value 767 */ 768static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) 769{ 770 return nla_put(skb, attrtype, sizeof(u16), &value); 771} 772 773/** 774 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 775 * @skb: socket buffer to add attribute to 776 * @attrtype: attribute type 777 * @value: numeric value 778 */ 779static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 780{ 781 return nla_put(skb, attrtype, sizeof(u32), &value); 782} 783 784/** 785 * nla_put_64 - Add a u64 netlink attribute to a socket buffer 786 * @skb: socket buffer to add attribute to 787 * @attrtype: attribute type 788 * @value: numeric value 789 */ 790static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value) 791{ 792 return nla_put(skb, attrtype, sizeof(u64), &value); 793} 794 795/** 796 * nla_put_string - Add a string netlink attribute to a socket buffer 797 * @skb: socket buffer to add attribute to 798 * @attrtype: attribute type 799 * @str: NUL terminated string 800 */ 801static inline int nla_put_string(struct sk_buff *skb, int attrtype, 802 const char *str) 803{ 804 return nla_put(skb, attrtype, strlen(str) + 1, str); 805} 806 807/** 808 * nla_put_flag - Add a flag netlink attribute to a socket buffer 809 * @skb: socket buffer to add attribute to 810 * @attrtype: attribute type 811 */ 812static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 813{ 814 return nla_put(skb, attrtype, 0, NULL); 815} 816 817/** 818 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer 819 * @skb: socket buffer to add attribute to 820 * @attrtype: attribute type 821 * @jiffies: number of msecs in jiffies 822 */ 823static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 824 unsigned long jiffies) 825{ 826 u64 tmp = jiffies_to_msecs(jiffies); 827 return nla_put(skb, attrtype, sizeof(u64), &tmp); 828} 829 830#define NLA_PUT(skb, attrtype, attrlen, data) \ 831 do { \ 832 if (unlikely(nla_put(skb, attrtype, attrlen, data) < 0)) \ 833 goto nla_put_failure; \ 834 } while(0) 835 836#define NLA_PUT_TYPE(skb, type, attrtype, value) \ 837 do { \ 838 type __tmp = value; \ 839 NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \ 840 } while(0) 841 842#define NLA_PUT_U8(skb, attrtype, value) \ 843 NLA_PUT_TYPE(skb, u8, attrtype, value) 844 845#define NLA_PUT_U16(skb, attrtype, value) \ 846 NLA_PUT_TYPE(skb, u16, attrtype, value) 847 848#define NLA_PUT_LE16(skb, attrtype, value) \ 849 NLA_PUT_TYPE(skb, __le16, attrtype, value) 850 851#define NLA_PUT_BE16(skb, attrtype, value) \ 852 NLA_PUT_TYPE(skb, __be16, attrtype, value) 853 854#define NLA_PUT_U32(skb, attrtype, value) \ 855 NLA_PUT_TYPE(skb, u32, attrtype, value) 856 857#define NLA_PUT_BE32(skb, attrtype, value) \ 858 NLA_PUT_TYPE(skb, __be32, attrtype, value) 859 860#define NLA_PUT_U64(skb, attrtype, value) \ 861 NLA_PUT_TYPE(skb, u64, attrtype, value) 862 863#define NLA_PUT_BE64(skb, attrtype, value) \ 864 NLA_PUT_TYPE(skb, __be64, attrtype, value) 865 866#define NLA_PUT_STRING(skb, attrtype, value) \ 867 NLA_PUT(skb, attrtype, strlen(value) + 1, value) 868 869#define NLA_PUT_FLAG(skb, attrtype) \ 870 NLA_PUT(skb, attrtype, 0, NULL) 871 872#define NLA_PUT_MSECS(skb, attrtype, jiffies) \ 873 NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies)) 874 875/** 876 * nla_get_u32 - return payload of u32 attribute 877 * @nla: u32 netlink attribute 878 */ 879static inline u32 nla_get_u32(const struct nlattr *nla) 880{ 881 return *(u32 *) nla_data(nla); 882} 883 884/** 885 * nla_get_be32 - return payload of __be32 attribute 886 * @nla: __be32 netlink attribute 887 */ 888static inline __be32 nla_get_be32(const struct nlattr *nla) 889{ 890 return *(__be32 *) nla_data(nla); 891} 892 893/** 894 * nla_get_u16 - return payload of u16 attribute 895 * @nla: u16 netlink attribute 896 */ 897static inline u16 nla_get_u16(const struct nlattr *nla) 898{ 899 return *(u16 *) nla_data(nla); 900} 901 902/** 903 * nla_get_be16 - return payload of __be16 attribute 904 * @nla: __be16 netlink attribute 905 */ 906static inline __be16 nla_get_be16(const struct nlattr *nla) 907{ 908 return *(__be16 *) nla_data(nla); 909} 910 911/** 912 * nla_get_le16 - return payload of __le16 attribute 913 * @nla: __le16 netlink attribute 914 */ 915static inline __le16 nla_get_le16(const struct nlattr *nla) 916{ 917 return *(__le16 *) nla_data(nla); 918} 919 920/** 921 * nla_get_u8 - return payload of u8 attribute 922 * @nla: u8 netlink attribute 923 */ 924static inline u8 nla_get_u8(const struct nlattr *nla) 925{ 926 return *(u8 *) nla_data(nla); 927} 928 929/** 930 * nla_get_u64 - return payload of u64 attribute 931 * @nla: u64 netlink attribute 932 */ 933static inline u64 nla_get_u64(const struct nlattr *nla) 934{ 935 u64 tmp; 936 937 nla_memcpy(&tmp, nla, sizeof(tmp)); 938 939 return tmp; 940} 941 942/** 943 * nla_get_be64 - return payload of __be64 attribute 944 * @nla: __be64 netlink attribute 945 */ 946static inline __be64 nla_get_be64(const struct nlattr *nla) 947{ 948 return *(__be64 *) nla_data(nla); 949} 950 951/** 952 * nla_get_flag - return payload of flag attribute 953 * @nla: flag netlink attribute 954 */ 955static inline int nla_get_flag(const struct nlattr *nla) 956{ 957 return !!nla; 958} 959 960/** 961 * nla_get_msecs - return payload of msecs attribute 962 * @nla: msecs netlink attribute 963 * 964 * Returns the number of milliseconds in jiffies. 965 */ 966static inline unsigned long nla_get_msecs(const struct nlattr *nla) 967{ 968 u64 msecs = nla_get_u64(nla); 969 970 return msecs_to_jiffies((unsigned long) msecs); 971} 972 973/** 974 * nla_nest_start - Start a new level of nested attributes 975 * @skb: socket buffer to add attributes to 976 * @attrtype: attribute type of container 977 * 978 * Returns the container attribute 979 */ 980static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 981{ 982 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 983 984 if (nla_put(skb, attrtype, 0, NULL) < 0) 985 return NULL; 986 987 return start; 988} 989 990/** 991 * nla_nest_end - Finalize nesting of attributes 992 * @skb: socket buffer the attributes are stored in 993 * @start: container attribute 994 * 995 * Corrects the container attribute header to include the all 996 * appeneded attributes. 997 * 998 * Returns the total data length of the skb. 999 */ 1000static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
1001{ 1002 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1003 return skb->len; 1004} 1005 1006/** 1007 * nla_nest_cancel - Cancel nesting of attributes 1008 * @skb: socket buffer the message is stored in 1009 * @start: container attribute 1010 * 1011 * Removes the container attribute and including all nested 1012 * attributes. Returns -EMSGSIZE 1013 */ 1014static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 1015{ 1016 nlmsg_trim(skb, start); 1017} 1018 1019/** 1020 * nla_validate_nested - Validate a stream of nested attributes 1021 * @start: container attribute 1022 * @maxtype: maximum attribute type to be expected 1023 * @policy: validation policy 1024 * 1025 * Validates all attributes in the nested attribute stream against the 1026 * specified policy. Attributes with a type exceeding maxtype will be 1027 * ignored. See documenation of struct nla_policy for more details. 1028 * 1029 * Returns 0 on success or a negative error code. 1030 */ 1031static inline int nla_validate_nested(struct nlattr *start, int maxtype, 1032 const struct nla_policy *policy) 1033{ 1034 return nla_validate(nla_data(start), nla_len(start), maxtype, policy); 1035} 1036 1037/** 1038 * nla_for_each_attr - iterate over a stream of attributes 1039 * @pos: loop counter, set to current attribute 1040 * @head: head of attribute stream 1041 * @len: length of attribute stream 1042 * @rem: initialized to len, holds bytes currently remaining in stream 1043 */ 1044#define nla_for_each_attr(pos, head, len, rem) \ 1045 for (pos = head, rem = len; \ 1046 nla_ok(pos, rem); \ 1047 pos = nla_next(pos, &(rem))) 1048 1049/** 1050 * nla_for_each_nested - iterate over nested attributes 1051 * @pos: loop counter, set to current attribute 1052 * @nla: attribute containing the nested attributes 1053 * @rem: initialized to len, holds bytes currently remaining in stream 1054 */ 1055#define nla_for_each_nested(pos, nla, rem) \ 1056 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 1057 1058#endif 1059