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_compat_start(skb, type, start a nested compat attribute 123 * len, data) 124 * nla_nest_compat_end(skb, type) finalize a nested compat attribute 125 * nla_nest_cancel(skb, nla) cancel nested attribute construction 126 * 127 * Attribute Length Calculations: 128 * nla_attr_size(payload) length of attribute w/o padding 129 * nla_total_size(payload) length of attribute w/ padding 130 * nla_padlen(payload) length of padding 131 * 132 * Attribute Payload Access: 133 * nla_data(nla) head of attribute payload 134 * nla_len(nla) length of attribute payload 135 * 136 * Attribute Payload Access for Basic Types: 137 * nla_get_u8(nla) get payload for a u8 attribute 138 * nla_get_u16(nla) get payload for a u16 attribute 139 * nla_get_u32(nla) get payload for a u32 attribute 140 * nla_get_u64(nla) get payload for a u64 attribute 141 * nla_get_flag(nla) return 1 if flag is true 142 * nla_get_msecs(nla) get payload for a msecs attribute 143 * 144 * Attribute Misc: 145 * nla_memcpy(dest, nla, count) copy attribute into memory 146 * nla_memcmp(nla, data, size) compare attribute with memory area 147 * nla_strlcpy(dst, nla, size) copy attribute to a sized string 148 * nla_strcmp(nla, str) compare attribute with string 149 * 150 * Attribute Parsing: 151 * nla_ok(nla, remaining) does nla fit into remaining bytes? 152 * nla_next(nla, remaining) get next netlink attribute 153 * nla_validate() validate a stream of attributes 154 * nla_validate_nested() validate a stream of nested attributes 155 * nla_find() find attribute in stream of attributes 156 * nla_find_nested() find attribute in nested attributes 157 * nla_parse() parse and validate stream of attrs 158 * nla_parse_nested() parse nested attribuets 159 * nla_parse_nested_compat() parse nested compat attributes 160 * nla_for_each_attr() loop over all attributes 161 * nla_for_each_nested() loop over the nested attributes 162 *========================================================================= 163 */ 164 165 /** 166 * Standard attribute types to specify validation policy 167 */ 168enum { 169 NLA_UNSPEC, 170 NLA_U8, 171 NLA_U16, 172 NLA_U32, 173 NLA_U64, 174 NLA_STRING, 175 NLA_FLAG, 176 NLA_MSECS, 177 NLA_NESTED, 178 NLA_NESTED_COMPAT, 179 NLA_NUL_STRING, 180 NLA_BINARY, 181 __NLA_TYPE_MAX, 182}; 183 184#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) 185 186/** 187 * struct nla_policy - attribute validation policy 188 * @type: Type of attribute or NLA_UNSPEC 189 * @len: Type specific length of payload 190 * 191 * Policies are defined as arrays of this struct, the array must be 192 * accessible by attribute type up to the highest identifier to be expected. 193 * 194 * Meaning of `len' field: 195 * NLA_STRING Maximum length of string 196 * NLA_NUL_STRING Maximum length of string (excluding NUL) 197 * NLA_FLAG Unused 198 * NLA_BINARY Maximum length of attribute payload 199 * NLA_NESTED_COMPAT Exact length of structure payload 200 * All other Exact length of attribute payload 201 * 202 * Example: 203 * static struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = { 204 * [ATTR_FOO] = { .type = NLA_U16 }, 205 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, 206 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) }, 207 * }; 208 */ 209struct nla_policy { 210 u16 type; 211 u16 len; 212}; 213 214/** 215 * struct nl_info - netlink source information 216 * @nlh: Netlink message header of original request 217 * @pid: Netlink PID of requesting application 218 */ 219struct nl_info { 220 struct nlmsghdr *nlh; 221 struct net *nl_net; 222 u32 pid; 223}; 224 225extern int netlink_rcv_skb(struct sk_buff *skb, 226 int (*cb)(struct sk_buff *, 227 struct nlmsghdr *)); 228extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb, 229 u32 pid, unsigned int group, int report, 230 gfp_t flags); 231 232extern int nla_validate(struct nlattr *head, int len, int maxtype, 233 const struct nla_policy *policy); 234extern int nla_parse(struct nlattr *tb[], int maxtype, 235 struct nlattr *head, int len, 236 const struct nla_policy *policy); 237extern struct nlattr * nla_find(struct nlattr *head, int len, int attrtype); 238extern size_t nla_strlcpy(char *dst, const struct nlattr *nla, 239 size_t dstsize); 240extern int nla_memcpy(void *dest, struct nlattr *src, int count); 241extern int nla_memcmp(const struct nlattr *nla, const void *data, 242 size_t size); 243extern int nla_strcmp(const struct nlattr *nla, const char *str); 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 struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype, 248 int attrlen); 249extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 250extern void __nla_put(struct sk_buff *skb, int attrtype, 251 int attrlen, const void *data); 252extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen, 253 const void *data); 254extern int nla_put(struct sk_buff *skb, int attrtype, 255 int attrlen, const void *data); 256extern int nla_put_nohdr(struct sk_buff *skb, int attrlen, 257 const void *data); 258extern int nla_append(struct sk_buff *skb, int attrlen, 259 const void *data); 260 261/************************************************************************** 262 * Netlink Messages 263 **************************************************************************/ 264 265/** 266 * nlmsg_msg_size - length of netlink message not including padding 267 * @payload: length of message payload 268 */ 269static inline int nlmsg_msg_size(int payload) 270{ 271 return NLMSG_HDRLEN + payload; 272} 273 274/** 275 * nlmsg_total_size - length of netlink message including padding 276 * @payload: length of message payload 277 */ 278static inline int nlmsg_total_size(int payload) 279{ 280 return NLMSG_ALIGN(nlmsg_msg_size(payload)); 281} 282 283/** 284 * nlmsg_padlen - length of padding at the message's tail 285 * @payload: length of message payload 286 */ 287static inline int nlmsg_padlen(int payload) 288{ 289 return nlmsg_total_size(payload) - nlmsg_msg_size(payload); 290} 291 292/** 293 * nlmsg_data - head of message payload 294 * @nlh: netlink messsage header 295 */ 296static inline void *nlmsg_data(const struct nlmsghdr *nlh) 297{ 298 return (unsigned char *) nlh + NLMSG_HDRLEN; 299} 300 301/** 302 * nlmsg_len - length of message payload 303 * @nlh: netlink message header 304 */ 305static inline int nlmsg_len(const struct nlmsghdr *nlh) 306{ 307 return nlh->nlmsg_len - NLMSG_HDRLEN; 308} 309 310/** 311 * nlmsg_attrdata - head of attributes data 312 * @nlh: netlink message header 313 * @hdrlen: length of family specific header 314 */ 315static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 316 int hdrlen) 317{ 318 unsigned char *data = nlmsg_data(nlh); 319 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); 320} 321 322/** 323 * nlmsg_attrlen - length of attributes data 324 * @nlh: netlink message header 325 * @hdrlen: length of family specific header 326 */ 327static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) 328{ 329 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); 330} 331 332/** 333 * nlmsg_ok - check if the netlink message fits into the remaining bytes 334 * @nlh: netlink message header 335 * @remaining: number of bytes remaining in message stream 336 */ 337static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) 338{ 339 return (remaining >= sizeof(struct nlmsghdr) && 340 nlh->nlmsg_len >= sizeof(struct nlmsghdr) && 341 nlh->nlmsg_len <= remaining); 342} 343 344/** 345 * nlmsg_next - next netlink message in message stream 346 * @nlh: netlink message header 347 * @remaining: number of bytes remaining in message stream 348 * 349 * Returns the next netlink message in the message stream and 350 * decrements remaining by the size of the current message. 351 */ 352static inline struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining) 353{ 354 int totlen = NLMSG_ALIGN(nlh->nlmsg_len); 355 356 *remaining -= totlen; 357 358 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); 359} 360 361/** 362 * nlmsg_parse - parse attributes of a netlink message 363 * @nlh: netlink message header 364 * @hdrlen: length of family specific header 365 * @tb: destination array with maxtype+1 elements 366 * @maxtype: maximum attribute type to be expected 367 * @policy: validation policy 368 * 369 * See nla_parse() 370 */ 371static inline int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen, 372 struct nlattr *tb[], int maxtype, 373 const struct nla_policy *policy) 374{ 375 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 376 return -EINVAL; 377 378 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 379 nlmsg_attrlen(nlh, hdrlen), policy); 380} 381 382/** 383 * nlmsg_find_attr - find a specific attribute in a netlink message 384 * @nlh: netlink message header 385 * @hdrlen: length of familiy specific header 386 * @attrtype: type of attribute to look for 387 * 388 * Returns the first attribute which matches the specified type. 389 */ 390static inline struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh, 391 int hdrlen, int attrtype) 392{ 393 return nla_find(nlmsg_attrdata(nlh, hdrlen), 394 nlmsg_attrlen(nlh, hdrlen), attrtype); 395} 396 397/** 398 * nlmsg_validate - validate a netlink message including attributes 399 * @nlh: netlinket message header 400 * @hdrlen: length of familiy specific header 401 * @maxtype: maximum attribute type to be expected 402 * @policy: validation policy 403 */ 404static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype, 405 const struct nla_policy *policy) 406{ 407 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 408 return -EINVAL; 409 410 return nla_validate(nlmsg_attrdata(nlh, hdrlen), 411 nlmsg_attrlen(nlh, hdrlen), maxtype, policy); 412} 413 414/** 415 * nlmsg_report - need to report back to application? 416 * @nlh: netlink message header 417 * 418 * Returns 1 if a report back to the application is requested. 419 */ 420static inline int nlmsg_report(struct nlmsghdr *nlh) 421{ 422 return !!(nlh->nlmsg_flags & NLM_F_ECHO); 423} 424 425/** 426 * nlmsg_for_each_attr - iterate over a stream of attributes 427 * @pos: loop counter, set to current attribute 428 * @nlh: netlink message header 429 * @hdrlen: length of familiy specific header 430 * @rem: initialized to len, holds bytes currently remaining in stream 431 */ 432#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ 433 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ 434 nlmsg_attrlen(nlh, hdrlen), rem) 435 436#if 0 437/* FIXME: Enable once all users have been converted */ 438 439/** 440 * __nlmsg_put - Add a new netlink message to an skb 441 * @skb: socket buffer to store message in 442 * @pid: netlink process id 443 * @seq: sequence number of message 444 * @type: message type 445 * @payload: length of message payload 446 * @flags: message flags 447 * 448 * The caller is responsible to ensure that the skb provides enough 449 * tailroom for both the netlink header and payload. 450 */ 451static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid, 452 u32 seq, int type, int payload, 453 int flags) 454{ 455 struct nlmsghdr *nlh; 456 457 nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload)); 458 nlh->nlmsg_type = type; 459 nlh->nlmsg_len = nlmsg_msg_size(payload); 460 nlh->nlmsg_flags = flags; 461 nlh->nlmsg_pid = pid; 462 nlh->nlmsg_seq = seq; 463 464 memset((unsigned char *) nlmsg_data(nlh) + payload, 0, 465 nlmsg_padlen(payload)); 466 467 return nlh; 468} 469#endif 470 471/** 472 * nlmsg_put - Add a new netlink message to an skb 473 * @skb: socket buffer to store message in 474 * @pid: netlink process id 475 * @seq: sequence number of message 476 * @type: message type 477 * @payload: length of message payload 478 * @flags: message flags 479 * 480 * Returns NULL if the tailroom of the skb is insufficient to store 481 * the message header and payload. 482 */ 483static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, 484 int type, int payload, int flags) 485{ 486 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) 487 return NULL; 488 489 return __nlmsg_put(skb, pid, seq, type, payload, flags); 490} 491 492/** 493 * nlmsg_put_answer - Add a new callback based netlink message to an skb 494 * @skb: socket buffer to store message in 495 * @cb: netlink callback 496 * @type: message type 497 * @payload: length of message payload 498 * @flags: message flags 499 * 500 * Returns NULL if the tailroom of the skb is insufficient to store 501 * the message header and payload. 502 */ 503static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, 504 struct netlink_callback *cb, 505 int type, int payload, 506 int flags) 507{ 508 return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, 509 type, payload, flags); 510} 511 512/** 513 * nlmsg_new - Allocate a new netlink message 514 * @payload: size of the message payload 515 * @flags: the type of memory to allocate. 516 * 517 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known 518 * and a good default is needed. 519 */ 520static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) 521{ 522 return alloc_skb(nlmsg_total_size(payload), flags); 523} 524 525/** 526 * nlmsg_end - Finalize a netlink message 527 * @skb: socket buffer the message is stored in 528 * @nlh: netlink message header 529 * 530 * Corrects the netlink message header to include the appeneded 531 * attributes. Only necessary if attributes have been added to 532 * the message. 533 * 534 * Returns the total data length of the skb. 535 */ 536static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 537{ 538 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 539 540 return skb->len; 541} 542 543/** 544 * nlmsg_get_pos - return current position in netlink message 545 * @skb: socket buffer the message is stored in 546 * 547 * Returns a pointer to the current tail of the message. 548 */ 549static inline void *nlmsg_get_pos(struct sk_buff *skb) 550{ 551 return skb_tail_pointer(skb); 552} 553 554/** 555 * nlmsg_trim - Trim message to a mark 556 * @skb: socket buffer the message is stored in 557 * @mark: mark to trim to 558 * 559 * Trims the message to the provided mark. 560 */ 561static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 562{ 563 if (mark) 564 skb_trim(skb, (unsigned char *) mark - skb->data); 565} 566 567/** 568 * nlmsg_cancel - Cancel construction of a netlink message 569 * @skb: socket buffer the message is stored in 570 * @nlh: netlink message header 571 * 572 * Removes the complete netlink message including all 573 * attributes from the socket buffer again. 574 */ 575static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 576{ 577 nlmsg_trim(skb, nlh); 578} 579 580/** 581 * nlmsg_free - free a netlink message 582 * @skb: socket buffer of netlink message 583 */ 584static inline void nlmsg_free(struct sk_buff *skb) 585{ 586 kfree_skb(skb); 587} 588 589/** 590 * nlmsg_multicast - multicast a netlink message 591 * @sk: netlink socket to spread messages to 592 * @skb: netlink message as socket buffer 593 * @pid: own netlink pid to avoid sending to yourself 594 * @group: multicast group id 595 * @flags: allocation flags 596 */ 597static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 598 u32 pid, unsigned int group, gfp_t flags) 599{ 600 int err; 601 602 NETLINK_CB(skb).dst_group = group; 603 604 err = netlink_broadcast(sk, skb, pid, group, flags); 605 if (err > 0) 606 err = 0; 607 608 return err; 609} 610 611/** 612 * nlmsg_unicast - unicast a netlink message 613 * @sk: netlink socket to spread message to 614 * @skb: netlink message as socket buffer 615 * @pid: netlink pid of the destination socket 616 */ 617static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid) 618{ 619 int err; 620 621 err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT); 622 if (err > 0) 623 err = 0; 624 625 return err; 626} 627 628/** 629 * nlmsg_for_each_msg - iterate over a stream of messages 630 * @pos: loop counter, set to current message 631 * @head: head of message stream 632 * @len: length of message stream 633 * @rem: initialized to len, holds bytes currently remaining in stream 634 */ 635#define nlmsg_for_each_msg(pos, head, len, rem) \ 636 for (pos = head, rem = len; \ 637 nlmsg_ok(pos, rem); \ 638 pos = nlmsg_next(pos, &(rem))) 639 640/************************************************************************** 641 * Netlink Attributes 642 **************************************************************************/ 643 644/** 645 * nla_attr_size - length of attribute not including padding 646 * @payload: length of payload 647 */ 648static inline int nla_attr_size(int payload) 649{ 650 return NLA_HDRLEN + payload; 651} 652 653/** 654 * nla_total_size - total length of attribute including padding 655 * @payload: length of payload 656 */ 657static inline int nla_total_size(int payload) 658{ 659 return NLA_ALIGN(nla_attr_size(payload)); 660} 661 662/** 663 * nla_padlen - length of padding at the tail of attribute 664 * @payload: length of payload 665 */ 666static inline int nla_padlen(int payload) 667{ 668 return nla_total_size(payload) - nla_attr_size(payload); 669} 670 671/** 672 * nla_type - attribute type 673 * @nla: netlink attribute 674 */ 675static inline int nla_type(const struct nlattr *nla) 676{ 677 return nla->nla_type & NLA_TYPE_MASK; 678} 679 680/** 681 * nla_data - head of payload 682 * @nla: netlink attribute 683 */ 684static inline void *nla_data(const struct nlattr *nla) 685{ 686 return (char *) nla + NLA_HDRLEN; 687} 688 689/** 690 * nla_len - length of payload 691 * @nla: netlink attribute 692 */ 693static inline int nla_len(const struct nlattr *nla) 694{ 695 return nla->nla_len - NLA_HDRLEN; 696} 697 698/** 699 * nla_ok - check if the netlink attribute fits into the remaining bytes 700 * @nla: netlink attribute 701 * @remaining: number of bytes remaining in attribute stream 702 */ 703static inline int nla_ok(const struct nlattr *nla, int remaining) 704{ 705 return remaining >= (int) sizeof(*nla) && 706 nla->nla_len >= sizeof(*nla) && 707 nla->nla_len <= remaining; 708} 709 710/** 711 * nla_next - next netlink attribute in attribute stream 712 * @nla: netlink attribute 713 * @remaining: number of bytes remaining in attribute stream 714 * 715 * Returns the next netlink attribute in the attribute stream and 716 * decrements remaining by the size of the current attribute. 717 */ 718static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 719{ 720 int totlen = NLA_ALIGN(nla->nla_len); 721 722 *remaining -= totlen; 723 return (struct nlattr *) ((char *) nla + totlen); 724} 725 726/** 727 * nla_find_nested - find attribute in a set of nested attributes 728 * @nla: attribute containing the nested attributes 729 * @attrtype: type of attribute to look for 730 * 731 * Returns the first attribute which matches the specified type. 732 */ 733static inline struct nlattr *nla_find_nested(struct nlattr *nla, int attrtype) 734{ 735 return nla_find(nla_data(nla), nla_len(nla), attrtype); 736} 737 738/** 739 * nla_parse_nested - parse nested attributes 740 * @tb: destination array with maxtype+1 elements 741 * @maxtype: maximum attribute type to be expected 742 * @nla: attribute containing the nested attributes 743 * @policy: validation policy 744 * 745 * See nla_parse() 746 */ 747static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 748 struct nlattr *nla, 749 const struct nla_policy *policy) 750{ 751 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); 752} 753 754/** 755 * nla_parse_nested_compat - parse nested compat attributes 756 * @tb: destination array with maxtype+1 elements 757 * @maxtype: maximum attribute type to be expected 758 * @nla: attribute containing the nested attributes 759 * @data: pointer to point to contained structure 760 * @len: length of contained structure 761 * @policy: validation policy 762 * 763 * Parse a nested compat attribute. The compat attribute contains a structure 764 * and optionally a set of nested attributes. On success the data pointer 765 * points to the nested data and tb contains the parsed attributes 766 * (see nla_parse). 767 */ 768static inline int __nla_parse_nested_compat(struct nlattr *tb[], int maxtype, 769 struct nlattr *nla, 770 const struct nla_policy *policy, 771 int len) 772{ 773 int nested_len = nla_len(nla) - NLA_ALIGN(len); 774 775 if (nested_len < 0) 776 return -EINVAL; 777 if (nested_len >= nla_attr_size(0)) 778 return nla_parse(tb, maxtype, nla_data(nla) + NLA_ALIGN(len), 779 nested_len, policy); 780 memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); 781 return 0; 782} 783 784#define nla_parse_nested_compat(tb, maxtype, nla, policy, data, len) \ 785({ data = nla_len(nla) >= len ? nla_data(nla) : NULL; \ 786 __nla_parse_nested_compat(tb, maxtype, nla, policy, len); }) 787/** 788 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 789 * @skb: socket buffer to add attribute to 790 * @attrtype: attribute type 791 * @value: numeric value 792 */ 793static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 794{ 795 return nla_put(skb, attrtype, sizeof(u8), &value); 796} 797 798/** 799 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer 800 * @skb: socket buffer to add attribute to 801 * @attrtype: attribute type 802 * @value: numeric value 803 */ 804static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) 805{ 806 return nla_put(skb, attrtype, sizeof(u16), &value); 807} 808 809/** 810 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 811 * @skb: socket buffer to add attribute to 812 * @attrtype: attribute type 813 * @value: numeric value 814 */ 815static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 816{ 817 return nla_put(skb, attrtype, sizeof(u32), &value); 818} 819 820/** 821 * nla_put_64 - Add a u64 netlink attribute to a socket buffer 822 * @skb: socket buffer to add attribute to 823 * @attrtype: attribute type 824 * @value: numeric value 825 */ 826static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value) 827{ 828 return nla_put(skb, attrtype, sizeof(u64), &value); 829} 830 831/** 832 * nla_put_string - Add a string netlink attribute to a socket buffer 833 * @skb: socket buffer to add attribute to 834 * @attrtype: attribute type 835 * @str: NUL terminated string 836 */ 837static inline int nla_put_string(struct sk_buff *skb, int attrtype, 838 const char *str) 839{ 840 return nla_put(skb, attrtype, strlen(str) + 1, str); 841} 842 843/** 844 * nla_put_flag - Add a flag netlink attribute to a socket buffer 845 * @skb: socket buffer to add attribute to 846 * @attrtype: attribute type 847 */ 848static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 849{ 850 return nla_put(skb, attrtype, 0, NULL); 851} 852 853/** 854 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer 855 * @skb: socket buffer to add attribute to 856 * @attrtype: attribute type 857 * @jiffies: number of msecs in jiffies 858 */ 859static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 860 unsigned long jiffies) 861{ 862 u64 tmp = jiffies_to_msecs(jiffies); 863 return nla_put(skb, attrtype, sizeof(u64), &tmp); 864} 865 866#define NLA_PUT(skb, attrtype, attrlen, data) \ 867 do { \ 868 if (unlikely(nla_put(skb, attrtype, attrlen, data) < 0)) \ 869 goto nla_put_failure; \ 870 } while(0) 871 872#define NLA_PUT_TYPE(skb, type, attrtype, value) \ 873 do { \ 874 type __tmp = value; \ 875 NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \ 876 } while(0) 877 878#define NLA_PUT_U8(skb, attrtype, value) \ 879 NLA_PUT_TYPE(skb, u8, attrtype, value) 880 881#define NLA_PUT_U16(skb, attrtype, value) \ 882 NLA_PUT_TYPE(skb, u16, attrtype, value) 883 884#define NLA_PUT_LE16(skb, attrtype, value) \ 885 NLA_PUT_TYPE(skb, __le16, attrtype, value) 886 887#define NLA_PUT_BE16(skb, attrtype, value) \ 888 NLA_PUT_TYPE(skb, __be16, attrtype, value) 889 890#define NLA_PUT_U32(skb, attrtype, value) \ 891 NLA_PUT_TYPE(skb, u32, attrtype, value) 892 893#define NLA_PUT_BE32(skb, attrtype, value) \ 894 NLA_PUT_TYPE(skb, __be32, attrtype, value) 895 896#define NLA_PUT_U64(skb, attrtype, value) \ 897 NLA_PUT_TYPE(skb, u64, attrtype, value) 898 899#define NLA_PUT_BE64(skb, attrtype, value) \ 900 NLA_PUT_TYPE(skb, __be64, attrtype, value) 901 902#define NLA_PUT_STRING(skb, attrtype, value) \ 903 NLA_PUT(skb, attrtype, strlen(value) + 1, value) 904 905#define NLA_PUT_FLAG(skb, attrtype) \ 906 NLA_PUT(skb, attrtype, 0, NULL) 907 908#define NLA_PUT_MSECS(skb, attrtype, jiffies) \ 909 NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies)) 910 911/** 912 * nla_get_u32 - return payload of u32 attribute 913 * @nla: u32 netlink attribute 914 */ 915static inline u32 nla_get_u32(struct nlattr *nla) 916{ 917 return *(u32 *) nla_data(nla); 918} 919 920/** 921 * nla_get_be32 - return payload of __be32 attribute 922 * @nla: __be32 netlink attribute 923 */ 924static inline __be32 nla_get_be32(struct nlattr *nla) 925{ 926 return *(__be32 *) nla_data(nla); 927} 928 929/** 930 * nla_get_u16 - return payload of u16 attribute 931 * @nla: u16 netlink attribute 932 */ 933static inline u16 nla_get_u16(struct nlattr *nla) 934{ 935 return *(u16 *) nla_data(nla); 936} 937 938/** 939 * nla_get_be16 - return payload of __be16 attribute 940 * @nla: __be16 netlink attribute 941 */ 942static inline __be16 nla_get_be16(struct nlattr *nla) 943{ 944 return *(__be16 *) nla_data(nla); 945} 946 947/** 948 * nla_get_le16 - return payload of __le16 attribute 949 * @nla: __le16 netlink attribute 950 */ 951static inline __le16 nla_get_le16(struct nlattr *nla) 952{ 953 return *(__le16 *) nla_data(nla); 954} 955 956/** 957 * nla_get_u8 - return payload of u8 attribute 958 * @nla: u8 netlink attribute 959 */ 960static inline u8 nla_get_u8(struct nlattr *nla) 961{ 962 return *(u8 *) nla_data(nla); 963} 964 965/** 966 * nla_get_u64 - return payload of u64 attribute 967 * @nla: u64 netlink attribute 968 */ 969static inline u64 nla_get_u64(struct nlattr *nla) 970{ 971 u64 tmp; 972 973 nla_memcpy(&tmp, nla, sizeof(tmp)); 974 975 return tmp; 976} 977 978/** 979 * nla_get_flag - return payload of flag attribute 980 * @nla: flag netlink attribute 981 */ 982static inline int nla_get_flag(struct nlattr *nla) 983{ 984 return !!nla; 985} 986 987/** 988 * nla_get_msecs - return payload of msecs attribute 989 * @nla: msecs netlink attribute 990 * 991 * Returns the number of milliseconds in jiffies. 992 */ 993static inline unsigned long nla_get_msecs(struct nlattr *nla) 994{ 995 u64 msecs = nla_get_u64(nla); 996 997 return msecs_to_jiffies((unsigned long) msecs); 998} 999 1000/**
1001 * nla_nest_start - Start a new level of nested attributes 1002 * @skb: socket buffer to add attributes to 1003 * @attrtype: attribute type of container 1004 * 1005 * Returns the container attribute 1006 */ 1007static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 1008{ 1009 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 1010 1011 if (nla_put(skb, attrtype, 0, NULL) < 0) 1012 return NULL; 1013 1014 return start; 1015} 1016 1017/** 1018 * nla_nest_end - Finalize nesting of attributes 1019 * @skb: socket buffer the attributes are stored in 1020 * @start: container attribute 1021 * 1022 * Corrects the container attribute header to include the all 1023 * appeneded attributes. 1024 * 1025 * Returns the total data length of the skb. 1026 */ 1027static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 1028{ 1029 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1030 return skb->len; 1031} 1032 1033/** 1034 * nla_nest_compat_start - Start a new level of nested compat attributes 1035 * @skb: socket buffer to add attributes to 1036 * @attrtype: attribute type of container 1037 * @attrlen: length of structure 1038 * @data: pointer to structure 1039 * 1040 * Start a nested compat attribute that contains both a structure and 1041 * a set of nested attributes. 1042 * 1043 * Returns the container attribute 1044 */ 1045static inline struct nlattr *nla_nest_compat_start(struct sk_buff *skb, 1046 int attrtype, int attrlen, 1047 const void *data) 1048{ 1049 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 1050 1051 if (nla_put(skb, attrtype, attrlen, data) < 0) 1052 return NULL; 1053 if (nla_nest_start(skb, attrtype) == NULL) { 1054 nlmsg_trim(skb, start); 1055 return NULL; 1056 } 1057 return start; 1058} 1059 1060/** 1061 * nla_nest_compat_end - Finalize nesting of compat attributes 1062 * @skb: socket buffer the attributes are stored in 1063 * @start: container attribute 1064 * 1065 * Corrects the container attribute header to include the all 1066 * appeneded attributes. 1067 * 1068 * Returns the total data length of the skb. 1069 */ 1070static inline int nla_nest_compat_end(struct sk_buff *skb, struct nlattr *start) 1071{ 1072 struct nlattr *nest = (void *)start + NLMSG_ALIGN(start->nla_len); 1073 1074 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1075 return nla_nest_end(skb, nest); 1076} 1077 1078/** 1079 * nla_nest_cancel - Cancel nesting of attributes 1080 * @skb: socket buffer the message is stored in 1081 * @start: container attribute 1082 * 1083 * Removes the container attribute and including all nested 1084 * attributes. Returns -EMSGSIZE 1085 */ 1086static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 1087{ 1088 nlmsg_trim(skb, start); 1089} 1090 1091/** 1092 * nla_validate_nested - Validate a stream of nested attributes 1093 * @start: container attribute 1094 * @maxtype: maximum attribute type to be expected 1095 * @policy: validation policy 1096 * 1097 * Validates all attributes in the nested attribute stream against the 1098 * specified policy. Attributes with a type exceeding maxtype will be 1099 * ignored. See documenation of struct nla_policy for more details. 1100 * 1101 * Returns 0 on success or a negative error code. 1102 */ 1103static inline int nla_validate_nested(struct nlattr *start, int maxtype, 1104 const struct nla_policy *policy) 1105{ 1106 return nla_validate(nla_data(start), nla_len(start), maxtype, policy); 1107} 1108 1109/** 1110 * nla_for_each_attr - iterate over a stream of attributes 1111 * @pos: loop counter, set to current attribute 1112 * @head: head of attribute stream 1113 * @len: length of attribute stream 1114 * @rem: initialized to len, holds bytes currently remaining in stream 1115 */ 1116#define nla_for_each_attr(pos, head, len, rem) \ 1117 for (pos = head, rem = len; \ 1118 nla_ok(pos, rem); \ 1119 pos = nla_next(pos, &(rem))) 1120 1121/** 1122 * nla_for_each_nested - iterate over nested attributes 1123 * @pos: loop counter, set to current attribute 1124 * @nla: attribute containing the nested attributes 1125 * @rem: initialized to len, holds bytes currently remaining in stream 1126 */ 1127#define nla_for_each_nested(pos, nla, rem) \ 1128 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 1129 1130#endif 1131