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 Don't use `len' field -- length verification is 196 * done by checking len of nested header (or empty) 197 * NLA_NESTED_COMPAT Minimum length of structure payload 198 * NLA_U8, NLA_U16, 199 * NLA_U32, NLA_U64, 200 * NLA_MSECS Leaving the length field zero will verify the 201 * given type fits, using it verifies minimum length 202 * just like "All other" 203 * All other Minimum length of attribute payload 204 * 205 * Example: 206 * static const struct nla_policy my_policy[ATTR_MAX+1] = { 207 * [ATTR_FOO] = { .type = NLA_U16 }, 208 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, 209 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) }, 210 * }; 211 */ 212struct nla_policy { 213 u16 type; 214 u16 len; 215}; 216 217/** 218 * struct nl_info - netlink source information 219 * @nlh: Netlink message header of original request 220 * @pid: Netlink PID of requesting application 221 */ 222struct nl_info { 223 struct nlmsghdr *nlh; 224 struct net *nl_net; 225 u32 pid; 226}; 227 228extern int netlink_rcv_skb(struct sk_buff *skb, 229 int (*cb)(struct sk_buff *, 230 struct nlmsghdr *)); 231extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb, 232 u32 pid, unsigned int group, int report, 233 gfp_t flags); 234 235extern int nla_validate(const struct nlattr *head, 236 int len, int maxtype, 237 const struct nla_policy *policy); 238extern int nla_parse(struct nlattr **tb, int maxtype, 239 const struct nlattr *head, int len, 240 const struct nla_policy *policy); 241extern int nla_policy_len(const struct nla_policy *, int); 242extern struct nlattr * nla_find(const struct nlattr *head, 243 int len, int attrtype); 244extern size_t nla_strlcpy(char *dst, const struct nlattr *nla, 245 size_t dstsize); 246extern int nla_memcpy(void *dest, const struct nlattr *src, int count); 247extern int nla_memcmp(const struct nlattr *nla, const void *data, 248 size_t size); 249extern int nla_strcmp(const struct nlattr *nla, const char *str); 250extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype, 251 int attrlen); 252extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 253extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype, 254 int attrlen); 255extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 256extern void __nla_put(struct sk_buff *skb, int attrtype, 257 int attrlen, const void *data); 258extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen, 259 const void *data); 260extern int nla_put(struct sk_buff *skb, int attrtype, 261 int attrlen, const void *data); 262extern int nla_put_nohdr(struct sk_buff *skb, int attrlen, 263 const void *data); 264extern int nla_append(struct sk_buff *skb, int attrlen, 265 const void *data); 266 267/************************************************************************** 268 * Netlink Messages 269 **************************************************************************/ 270 271/** 272 * nlmsg_msg_size - length of netlink message not including padding 273 * @payload: length of message payload 274 */ 275static inline int nlmsg_msg_size(int payload) 276{ 277 return NLMSG_HDRLEN + payload; 278} 279 280/** 281 * nlmsg_total_size - length of netlink message including padding 282 * @payload: length of message payload 283 */ 284static inline int nlmsg_total_size(int payload) 285{ 286 return NLMSG_ALIGN(nlmsg_msg_size(payload)); 287} 288 289/** 290 * nlmsg_padlen - length of padding at the message's tail 291 * @payload: length of message payload 292 */ 293static inline int nlmsg_padlen(int payload) 294{ 295 return nlmsg_total_size(payload) - nlmsg_msg_size(payload); 296} 297 298/** 299 * nlmsg_data - head of message payload 300 * @nlh: netlink message header 301 */ 302static inline void *nlmsg_data(const struct nlmsghdr *nlh) 303{ 304 return (unsigned char *) nlh + NLMSG_HDRLEN; 305} 306 307/** 308 * nlmsg_len - length of message payload 309 * @nlh: netlink message header 310 */ 311static inline int nlmsg_len(const struct nlmsghdr *nlh) 312{ 313 return nlh->nlmsg_len - NLMSG_HDRLEN; 314} 315 316/** 317 * nlmsg_attrdata - head of attributes data 318 * @nlh: netlink message header 319 * @hdrlen: length of family specific header 320 */ 321static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 322 int hdrlen) 323{ 324 unsigned char *data = nlmsg_data(nlh); 325 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); 326} 327 328/** 329 * nlmsg_attrlen - length of attributes data 330 * @nlh: netlink message header 331 * @hdrlen: length of family specific header 332 */ 333static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) 334{ 335 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); 336} 337 338/** 339 * nlmsg_ok - check if the netlink message fits into the remaining bytes 340 * @nlh: netlink message header 341 * @remaining: number of bytes remaining in message stream 342 */ 343static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) 344{ 345 return (remaining >= (int) sizeof(struct nlmsghdr) && 346 nlh->nlmsg_len >= sizeof(struct nlmsghdr) && 347 nlh->nlmsg_len <= remaining); 348} 349 350/** 351 * nlmsg_next - next netlink message in message stream 352 * @nlh: netlink message header 353 * @remaining: number of bytes remaining in message stream 354 * 355 * Returns the next netlink message in the message stream and 356 * decrements remaining by the size of the current message. 357 */ 358static inline struct nlmsghdr * 359nlmsg_next(const struct nlmsghdr *nlh, int *remaining) 360{ 361 int totlen = NLMSG_ALIGN(nlh->nlmsg_len); 362 363 *remaining -= totlen; 364 365 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); 366} 367 368/** 369 * nlmsg_parse - parse attributes of a netlink message 370 * @nlh: netlink message header 371 * @hdrlen: length of family specific header 372 * @tb: destination array with maxtype+1 elements 373 * @maxtype: maximum attribute type to be expected 374 * @policy: validation policy 375 * 376 * See nla_parse() 377 */ 378static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 379 struct nlattr *tb[], int maxtype, 380 const struct nla_policy *policy) 381{ 382 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 383 return -EINVAL; 384 385 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 386 nlmsg_attrlen(nlh, hdrlen), policy); 387} 388 389/** 390 * nlmsg_find_attr - find a specific attribute in a netlink message 391 * @nlh: netlink message header 392 * @hdrlen: length of familiy specific header 393 * @attrtype: type of attribute to look for 394 * 395 * Returns the first attribute which matches the specified type. 396 */ 397static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh, 398 int hdrlen, int attrtype) 399{ 400 return nla_find(nlmsg_attrdata(nlh, hdrlen), 401 nlmsg_attrlen(nlh, hdrlen), attrtype); 402} 403 404/** 405 * nlmsg_validate - validate a netlink message including attributes 406 * @nlh: netlinket message header 407 * @hdrlen: length of familiy specific header 408 * @maxtype: maximum attribute type to be expected 409 * @policy: validation policy 410 */ 411static inline int nlmsg_validate(const struct nlmsghdr *nlh, 412 int hdrlen, int maxtype, 413 const struct nla_policy *policy) 414{ 415 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 416 return -EINVAL; 417 418 return nla_validate(nlmsg_attrdata(nlh, hdrlen), 419 nlmsg_attrlen(nlh, hdrlen), maxtype, policy); 420} 421 422/** 423 * nlmsg_report - need to report back to application? 424 * @nlh: netlink message header 425 * 426 * Returns 1 if a report back to the application is requested. 427 */ 428static inline int nlmsg_report(const struct nlmsghdr *nlh) 429{ 430 return !!(nlh->nlmsg_flags & NLM_F_ECHO); 431} 432 433/** 434 * nlmsg_for_each_attr - iterate over a stream of attributes 435 * @pos: loop counter, set to current attribute 436 * @nlh: netlink message header 437 * @hdrlen: length of familiy specific header 438 * @rem: initialized to len, holds bytes currently remaining in stream 439 */ 440#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ 441 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ 442 nlmsg_attrlen(nlh, hdrlen), rem) 443 444#if 0 445/* FIXME: Enable once all users have been converted */ 446 447/** 448 * __nlmsg_put - Add a new netlink message to an skb 449 * @skb: socket buffer to store message in 450 * @pid: netlink process id 451 * @seq: sequence number of message 452 * @type: message type 453 * @payload: length of message payload 454 * @flags: message flags 455 * 456 * The caller is responsible to ensure that the skb provides enough 457 * tailroom for both the netlink header and payload. 458 */ 459static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid, 460 u32 seq, int type, int payload, 461 int flags) 462{ 463 struct nlmsghdr *nlh; 464 465 nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload)); 466 nlh->nlmsg_type = type; 467 nlh->nlmsg_len = nlmsg_msg_size(payload); 468 nlh->nlmsg_flags = flags; 469 nlh->nlmsg_pid = pid; 470 nlh->nlmsg_seq = seq; 471 472 memset((unsigned char *) nlmsg_data(nlh) + payload, 0, 473 nlmsg_padlen(payload)); 474 475 return nlh; 476} 477#endif 478 479/** 480 * nlmsg_put - Add a new netlink message to an skb 481 * @skb: socket buffer to store message in 482 * @pid: netlink process id 483 * @seq: sequence number of message 484 * @type: message type 485 * @payload: length of message payload 486 * @flags: message flags 487 * 488 * Returns NULL if the tailroom of the skb is insufficient to store 489 * the message header and payload. 490 */ 491static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, 492 int type, int payload, int flags) 493{ 494 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) 495 return NULL; 496 497 return __nlmsg_put(skb, pid, seq, type, payload, flags); 498} 499 500/** 501 * nlmsg_put_answer - Add a new callback based netlink message to an skb 502 * @skb: socket buffer to store message in 503 * @cb: netlink callback 504 * @type: message type 505 * @payload: length of message payload 506 * @flags: message flags 507 * 508 * Returns NULL if the tailroom of the skb is insufficient to store 509 * the message header and payload. 510 */ 511static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, 512 struct netlink_callback *cb, 513 int type, int payload, 514 int flags) 515{ 516 return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, 517 type, payload, flags); 518} 519 520/** 521 * nlmsg_new - Allocate a new netlink message 522 * @payload: size of the message payload 523 * @flags: the type of memory to allocate. 524 * 525 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known 526 * and a good default is needed. 527 */ 528static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) 529{ 530 return alloc_skb(nlmsg_total_size(payload), flags); 531} 532 533/** 534 * nlmsg_end - Finalize a netlink message 535 * @skb: socket buffer the message is stored in 536 * @nlh: netlink message header 537 * 538 * Corrects the netlink message header to include the appeneded 539 * attributes. Only necessary if attributes have been added to 540 * the message. 541 * 542 * Returns the total data length of the skb. 543 */ 544static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 545{ 546 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 547 548 return skb->len; 549} 550 551/** 552 * nlmsg_get_pos - return current position in netlink message 553 * @skb: socket buffer the message is stored in 554 * 555 * Returns a pointer to the current tail of the message. 556 */ 557static inline void *nlmsg_get_pos(struct sk_buff *skb) 558{ 559 return skb_tail_pointer(skb); 560} 561 562/** 563 * nlmsg_trim - Trim message to a mark 564 * @skb: socket buffer the message is stored in 565 * @mark: mark to trim to 566 * 567 * Trims the message to the provided mark. 568 */ 569static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 570{ 571 if (mark) 572 skb_trim(skb, (unsigned char *) mark - skb->data); 573} 574 575/** 576 * nlmsg_cancel - Cancel construction of a netlink message 577 * @skb: socket buffer the message is stored in 578 * @nlh: netlink message header 579 * 580 * Removes the complete netlink message including all 581 * attributes from the socket buffer again. 582 */ 583static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 584{ 585 nlmsg_trim(skb, nlh); 586} 587 588/** 589 * nlmsg_free - free a netlink message 590 * @skb: socket buffer of netlink message 591 */ 592static inline void nlmsg_free(struct sk_buff *skb) 593{ 594 kfree_skb(skb); 595} 596 597/** 598 * nlmsg_multicast - multicast a netlink message 599 * @sk: netlink socket to spread messages to 600 * @skb: netlink message as socket buffer 601 * @pid: own netlink pid to avoid sending to yourself 602 * @group: multicast group id 603 * @flags: allocation flags 604 */ 605static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 606 u32 pid, unsigned int group, gfp_t flags) 607{ 608 int err; 609 610 NETLINK_CB(skb).dst_group = group; 611 612 err = netlink_broadcast(sk, skb, pid, group, flags); 613 if (err > 0) 614 err = 0; 615 616 return err; 617} 618 619/** 620 * nlmsg_unicast - unicast a netlink message 621 * @sk: netlink socket to spread message to 622 * @skb: netlink message as socket buffer 623 * @pid: netlink pid of the destination socket 624 */ 625static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid) 626{ 627 int err; 628 629 err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT); 630 if (err > 0) 631 err = 0; 632 633 return err; 634} 635 636/** 637 * nlmsg_for_each_msg - iterate over a stream of messages 638 * @pos: loop counter, set to current message 639 * @head: head of message stream 640 * @len: length of message stream 641 * @rem: initialized to len, holds bytes currently remaining in stream 642 */ 643#define nlmsg_for_each_msg(pos, head, len, rem) \ 644 for (pos = head, rem = len; \ 645 nlmsg_ok(pos, rem); \ 646 pos = nlmsg_next(pos, &(rem))) 647 648/** 649 * nl_dump_check_consistent - check if sequence is consistent and advertise if not 650 * @cb: netlink callback structure that stores the sequence number 651 * @nlh: netlink message header to write the flag to 652 * 653 * This function checks if the sequence (generation) number changed during dump 654 * and if it did, advertises it in the netlink message header. 655 * 656 * The correct way to use it is to set cb->seq to the generation counter when 657 * all locks for dumping have been acquired, and then call this function for 658 * each message that is generated. 659 * 660 * Note that due to initialisation concerns, 0 is an invalid sequence number 661 * and must not be used by code that uses this functionality. 662 */ 663static inline void 664nl_dump_check_consistent(struct netlink_callback *cb, 665 struct nlmsghdr *nlh) 666{ 667 if (cb->prev_seq && cb->seq != cb->prev_seq) 668 nlh->nlmsg_flags |= NLM_F_DUMP_INTR; 669 cb->prev_seq = cb->seq; 670} 671 672/************************************************************************** 673 * Netlink Attributes 674 **************************************************************************/ 675 676/** 677 * nla_attr_size - length of attribute not including padding 678 * @payload: length of payload 679 */ 680static inline int nla_attr_size(int payload) 681{ 682 return NLA_HDRLEN + payload; 683} 684 685/** 686 * nla_total_size - total length of attribute including padding 687 * @payload: length of payload 688 */ 689static inline int nla_total_size(int payload) 690{ 691 return NLA_ALIGN(nla_attr_size(payload)); 692} 693 694/** 695 * nla_padlen - length of padding at the tail of attribute 696 * @payload: length of payload 697 */ 698static inline int nla_padlen(int payload) 699{ 700 return nla_total_size(payload) - nla_attr_size(payload); 701} 702 703/** 704 * nla_type - attribute type 705 * @nla: netlink attribute 706 */ 707static inline int nla_type(const struct nlattr *nla) 708{ 709 return nla->nla_type & NLA_TYPE_MASK; 710} 711 712/** 713 * nla_data - head of payload 714 * @nla: netlink attribute 715 */ 716static inline void *nla_data(const struct nlattr *nla) 717{ 718 return (char *) nla + NLA_HDRLEN; 719} 720 721/** 722 * nla_len - length of payload 723 * @nla: netlink attribute 724 */ 725static inline int nla_len(const struct nlattr *nla) 726{ 727 return nla->nla_len - NLA_HDRLEN; 728} 729 730/** 731 * nla_ok - check if the netlink attribute fits into the remaining bytes 732 * @nla: netlink attribute 733 * @remaining: number of bytes remaining in attribute stream 734 */ 735static inline int nla_ok(const struct nlattr *nla, int remaining) 736{ 737 return remaining >= (int) sizeof(*nla) && 738 nla->nla_len >= sizeof(*nla) && 739 nla->nla_len <= remaining; 740} 741 742/** 743 * nla_next - next netlink attribute in attribute stream 744 * @nla: netlink attribute 745 * @remaining: number of bytes remaining in attribute stream 746 * 747 * Returns the next netlink attribute in the attribute stream and 748 * decrements remaining by the size of the current attribute. 749 */ 750static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 751{ 752 int totlen = NLA_ALIGN(nla->nla_len); 753 754 *remaining -= totlen; 755 return (struct nlattr *) ((char *) nla + totlen); 756} 757 758/** 759 * nla_find_nested - find attribute in a set of nested attributes 760 * @nla: attribute containing the nested attributes 761 * @attrtype: type of attribute to look for 762 * 763 * Returns the first attribute which matches the specified type. 764 */ 765static inline struct nlattr * 766nla_find_nested(const struct nlattr *nla, int attrtype) 767{ 768 return nla_find(nla_data(nla), nla_len(nla), attrtype); 769} 770 771/** 772 * nla_parse_nested - parse nested attributes 773 * @tb: destination array with maxtype+1 elements 774 * @maxtype: maximum attribute type to be expected 775 * @nla: attribute containing the nested attributes 776 * @policy: validation policy 777 * 778 * See nla_parse() 779 */ 780static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 781 const struct nlattr *nla, 782 const struct nla_policy *policy) 783{ 784 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); 785} 786 787/** 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_NET16(skb, attrtype, value) \ 891 NLA_PUT_BE16(skb, attrtype | NLA_F_NET_BYTEORDER, value) 892 893#define NLA_PUT_U32(skb, attrtype, value) \ 894 NLA_PUT_TYPE(skb, u32, attrtype, value) 895 896#define NLA_PUT_BE32(skb, attrtype, value) \ 897 NLA_PUT_TYPE(skb, __be32, attrtype, value) 898 899#define NLA_PUT_NET32(skb, attrtype, value) \ 900 NLA_PUT_BE32(skb, attrtype | NLA_F_NET_BYTEORDER, value) 901 902#define NLA_PUT_U64(skb, attrtype, value) \ 903 NLA_PUT_TYPE(skb, u64, attrtype, value) 904 905#define NLA_PUT_BE64(skb, attrtype, value) \ 906 NLA_PUT_TYPE(skb, __be64, attrtype, value) 907 908#define NLA_PUT_NET64(skb, attrtype, value) \ 909 NLA_PUT_BE64(skb, attrtype | NLA_F_NET_BYTEORDER, value) 910 911#define NLA_PUT_STRING(skb, attrtype, value) \ 912 NLA_PUT(skb, attrtype, strlen(value) + 1, value) 913 914#define NLA_PUT_FLAG(skb, attrtype) \ 915 NLA_PUT(skb, attrtype, 0, NULL) 916 917#define NLA_PUT_MSECS(skb, attrtype, jiffies) \ 918 NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies)) 919 920/** 921 * nla_get_u32 - return payload of u32 attribute 922 * @nla: u32 netlink attribute 923 */ 924static inline u32 nla_get_u32(const struct nlattr *nla) 925{ 926 return *(u32 *) nla_data(nla); 927} 928 929/** 930 * nla_get_be32 - return payload of __be32 attribute 931 * @nla: __be32 netlink attribute 932 */ 933static inline __be32 nla_get_be32(const struct nlattr *nla) 934{ 935 return *(__be32 *) nla_data(nla); 936} 937 938/** 939 * nla_get_u16 - return payload of u16 attribute 940 * @nla: u16 netlink attribute 941 */ 942static inline u16 nla_get_u16(const struct nlattr *nla) 943{ 944 return *(u16 *) nla_data(nla); 945} 946 947/** 948 * nla_get_be16 - return payload of __be16 attribute 949 * @nla: __be16 netlink attribute 950 */ 951static inline __be16 nla_get_be16(const struct nlattr *nla) 952{ 953 return *(__be16 *) nla_data(nla); 954} 955 956/** 957 * nla_get_le16 - return payload of __le16 attribute 958 * @nla: __le16 netlink attribute 959 */ 960static inline __le16 nla_get_le16(const struct nlattr *nla) 961{ 962 return *(__le16 *) nla_data(nla); 963} 964 965/** 966 * nla_get_u8 - return payload of u8 attribute 967 * @nla: u8 netlink attribute 968 */ 969static inline u8 nla_get_u8(const struct nlattr *nla) 970{ 971 return *(u8 *) nla_data(nla); 972} 973 974/** 975 * nla_get_u64 - return payload of u64 attribute 976 * @nla: u64 netlink attribute 977 */ 978static inline u64 nla_get_u64(const struct nlattr *nla) 979{ 980 u64 tmp; 981 982 nla_memcpy(&tmp, nla, sizeof(tmp)); 983 984 return tmp; 985} 986 987/** 988 * nla_get_be64 - return payload of __be64 attribute 989 * @nla: __be64 netlink attribute 990 */ 991static inline __be64 nla_get_be64(const struct nlattr *nla) 992{ 993 __be64 tmp; 994 995 nla_memcpy(&tmp, nla, sizeof(tmp)); 996 997 return tmp; 998} 999 1000/**
1001 * nla_get_flag - return payload of flag attribute 1002 * @nla: flag netlink attribute 1003 */ 1004static inline int nla_get_flag(const struct nlattr *nla) 1005{ 1006 return !!nla; 1007} 1008 1009/** 1010 * nla_get_msecs - return payload of msecs attribute 1011 * @nla: msecs netlink attribute 1012 * 1013 * Returns the number of milliseconds in jiffies. 1014 */ 1015static inline unsigned long nla_get_msecs(const struct nlattr *nla) 1016{ 1017 u64 msecs = nla_get_u64(nla); 1018 1019 return msecs_to_jiffies((unsigned long) msecs); 1020} 1021 1022/** 1023 * nla_nest_start - Start a new level of nested attributes 1024 * @skb: socket buffer to add attributes to 1025 * @attrtype: attribute type of container 1026 * 1027 * Returns the container attribute 1028 */ 1029static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 1030{ 1031 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 1032 1033 if (nla_put(skb, attrtype, 0, NULL) < 0) 1034 return NULL; 1035 1036 return start; 1037} 1038 1039/** 1040 * nla_nest_end - Finalize nesting of attributes 1041 * @skb: socket buffer the attributes are stored in 1042 * @start: container attribute 1043 * 1044 * Corrects the container attribute header to include the all 1045 * appeneded attributes. 1046 * 1047 * Returns the total data length of the skb. 1048 */ 1049static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 1050{ 1051 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1052 return skb->len; 1053} 1054 1055/** 1056 * nla_nest_cancel - Cancel nesting of attributes 1057 * @skb: socket buffer the message is stored in 1058 * @start: container attribute 1059 * 1060 * Removes the container attribute and including all nested 1061 * attributes. Returns -EMSGSIZE 1062 */ 1063static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 1064{ 1065 nlmsg_trim(skb, start); 1066} 1067 1068/** 1069 * nla_validate_nested - Validate a stream of nested attributes 1070 * @start: container attribute 1071 * @maxtype: maximum attribute type to be expected 1072 * @policy: validation policy 1073 * 1074 * Validates all attributes in the nested attribute stream against the 1075 * specified policy. Attributes with a type exceeding maxtype will be 1076 * ignored. See documenation of struct nla_policy for more details. 1077 * 1078 * Returns 0 on success or a negative error code. 1079 */ 1080static inline int nla_validate_nested(const struct nlattr *start, int maxtype, 1081 const struct nla_policy *policy) 1082{ 1083 return nla_validate(nla_data(start), nla_len(start), maxtype, policy); 1084} 1085 1086/** 1087 * nla_for_each_attr - iterate over a stream of attributes 1088 * @pos: loop counter, set to current attribute 1089 * @head: head of attribute stream 1090 * @len: length of attribute stream 1091 * @rem: initialized to len, holds bytes currently remaining in stream 1092 */ 1093#define nla_for_each_attr(pos, head, len, rem) \ 1094 for (pos = head, rem = len; \ 1095 nla_ok(pos, rem); \ 1096 pos = nla_next(pos, &(rem))) 1097 1098/** 1099 * nla_for_each_nested - iterate over nested attributes 1100 * @pos: loop counter, set to current attribute 1101 * @nla: attribute containing the nested attributes 1102 * @rem: initialized to len, holds bytes currently remaining in stream 1103 */ 1104#define nla_for_each_nested(pos, nla, rem) \ 1105 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 1106 1107#endif 1108