1 #ifndef __NET_NETLINK_H 2 #define __NET_NETLINK_H 3 4 #include <linux/types.h> 5 #include <linux/netlink.h> 6 #include <linux/jiffies.h> 7 8 /* ======================================================================== 9 * Netlink Messages and Attributes Interface (As Seen On TV) 10 * ------------------------------------------------------------------------ 11 * Messages Interface 12 * ------------------------------------------------------------------------ 13 * 14 * Message Format: 15 * <--- nlmsg_total_size(payload) ---> 16 * <-- nlmsg_msg_size(payload) -> 17 * +----------+- - -+-------------+- - -+-------- - - 18 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr 19 * +----------+- - -+-------------+- - -+-------- - - 20 * nlmsg_data(nlh)---^ ^ 21 * nlmsg_next(nlh)-----------------------+ 22 * 23 * Payload Format: 24 * <---------------------- nlmsg_len(nlh) ---------------------> 25 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) -> 26 * +----------------------+- - -+--------------------------------+ 27 * | Family Header | Pad | Attributes | 28 * +----------------------+- - -+--------------------------------+ 29 * nlmsg_attrdata(nlh, hdrlen)---^ 30 * 31 * Data Structures: 32 * struct nlmsghdr netlink message header 33 * 34 * Message Construction: 35 * nlmsg_new() create a new netlink message 36 * nlmsg_put() add a netlink message to an skb 37 * nlmsg_put_answer() callback based nlmsg_put() 38 * nlmsg_end() finalize netlink message 39 * nlmsg_get_pos() return current position in message 40 * nlmsg_trim() trim part of message 41 * nlmsg_cancel() cancel message construction 42 * nlmsg_free() free a netlink message 43 * 44 * Message Sending: 45 * nlmsg_multicast() multicast message to several groups 46 * nlmsg_unicast() unicast a message to a single socket 47 * nlmsg_notify() send notification message 48 * 49 * Message Length Calculations: 50 * nlmsg_msg_size(payload) length of message w/o padding 51 * nlmsg_total_size(payload) length of message w/ padding 52 * nlmsg_padlen(payload) length of padding at tail 53 * 54 * Message Payload Access: 55 * nlmsg_data(nlh) head of message payload 56 * nlmsg_len(nlh) length of message payload 57 * nlmsg_attrdata(nlh, hdrlen) head of attributes data 58 * nlmsg_attrlen(nlh, hdrlen) length of attributes data 59 * 60 * Message Parsing: 61 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes? 62 * nlmsg_next(nlh, remaining) get next netlink message 63 * nlmsg_parse() parse attributes of a message 64 * nlmsg_find_attr() find an attribute in a message 65 * nlmsg_for_each_msg() loop over all messages 66 * nlmsg_validate() validate netlink message incl. attrs 67 * nlmsg_for_each_attr() loop over all attributes 68 * 69 * Misc: 70 * nlmsg_report() report back to application? 71 * 72 * ------------------------------------------------------------------------ 73 * Attributes Interface 74 * ------------------------------------------------------------------------ 75 * 76 * Attribute Format: 77 * <------- nla_total_size(payload) -------> 78 * <---- nla_attr_size(payload) -----> 79 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 80 * | Header | Pad | Payload | Pad | Header 81 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 82 * <- nla_len(nla) -> ^ 83 * nla_data(nla)----^ | 84 * nla_next(nla)-----------------------------' 85 * 86 * Data Structures: 87 * struct nlattr netlink attribute header 88 * 89 * Attribute Construction: 90 * nla_reserve(skb, type, len) reserve room for an attribute 91 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr 92 * nla_put(skb, type, len, data) add attribute to skb 93 * nla_put_nohdr(skb, len, data) add attribute w/o hdr 94 * nla_append(skb, len, data) append data to skb 95 * 96 * Attribute Construction for Basic Types: 97 * nla_put_u8(skb, type, value) add u8 attribute to skb 98 * nla_put_u16(skb, type, value) add u16 attribute to skb 99 * nla_put_u32(skb, type, value) add u32 attribute to skb 100 * nla_put_u64(skb, type, value) add u64 attribute to skb 101 * nla_put_s8(skb, type, value) add s8 attribute to skb 102 * nla_put_s16(skb, type, value) add s16 attribute to skb 103 * nla_put_s32(skb, type, value) add s32 attribute to skb 104 * nla_put_s64(skb, type, value) add s64 attribute to skb 105 * nla_put_string(skb, type, str) add string attribute to skb 106 * nla_put_flag(skb, type) add flag attribute to skb 107 * nla_put_msecs(skb, type, jiffies) add msecs attribute to skb 108 * 109 * Nested Attributes Construction: 110 * nla_nest_start(skb, type) start a nested attribute 111 * nla_nest_end(skb, nla) finalize a nested attribute 112 * nla_nest_cancel(skb, nla) cancel nested attribute construction 113 * 114 * Attribute Length Calculations: 115 * nla_attr_size(payload) length of attribute w/o padding 116 * nla_total_size(payload) length of attribute w/ padding 117 * nla_padlen(payload) length of padding 118 * 119 * Attribute Payload Access: 120 * nla_data(nla) head of attribute payload 121 * nla_len(nla) length of attribute payload 122 * 123 * Attribute Payload Access for Basic Types: 124 * nla_get_u8(nla) get payload for a u8 attribute 125 * nla_get_u16(nla) get payload for a u16 attribute 126 * nla_get_u32(nla) get payload for a u32 attribute 127 * nla_get_u64(nla) get payload for a u64 attribute 128 * nla_get_s8(nla) get payload for a s8 attribute 129 * nla_get_s16(nla) get payload for a s16 attribute 130 * nla_get_s32(nla) get payload for a s32 attribute 131 * nla_get_s64(nla) get payload for a s64 attribute 132 * nla_get_flag(nla) return 1 if flag is true 133 * nla_get_msecs(nla) get payload for a msecs attribute 134 * 135 * Attribute Misc: 136 * nla_memcpy(dest, nla, count) copy attribute into memory 137 * nla_memcmp(nla, data, size) compare attribute with memory area 138 * nla_strlcpy(dst, nla, size) copy attribute to a sized string 139 * nla_strcmp(nla, str) compare attribute with string 140 * 141 * Attribute Parsing: 142 * nla_ok(nla, remaining) does nla fit into remaining bytes? 143 * nla_next(nla, remaining) get next netlink attribute 144 * nla_validate() validate a stream of attributes 145 * nla_validate_nested() validate a stream of nested attributes 146 * nla_find() find attribute in stream of attributes 147 * nla_find_nested() find attribute in nested attributes 148 * nla_parse() parse and validate stream of attrs 149 * nla_parse_nested() parse nested attribuets 150 * nla_for_each_attr() loop over all attributes 151 * nla_for_each_nested() loop over the nested attributes 152 *========================================================================= 153 */ 154 155 /** 156 * Standard attribute types to specify validation policy 157 */ 158 enum { 159 NLA_UNSPEC, 160 NLA_U8, 161 NLA_U16, 162 NLA_U32, 163 NLA_U64, 164 NLA_STRING, 165 NLA_FLAG, 166 NLA_MSECS, 167 NLA_NESTED, 168 NLA_NESTED_COMPAT, 169 NLA_NUL_STRING, 170 NLA_BINARY, 171 NLA_S8, 172 NLA_S16, 173 NLA_S32, 174 NLA_S64, 175 __NLA_TYPE_MAX, 176 }; 177 178 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) 179 180 /** 181 * struct nla_policy - attribute validation policy 182 * @type: Type of attribute or NLA_UNSPEC 183 * @len: Type specific length of payload 184 * 185 * Policies are defined as arrays of this struct, the array must be 186 * accessible by attribute type up to the highest identifier to be expected. 187 * 188 * Meaning of `len' field: 189 * NLA_STRING Maximum length of string 190 * NLA_NUL_STRING Maximum length of string (excluding NUL) 191 * NLA_FLAG Unused 192 * NLA_BINARY Maximum length of attribute payload 193 * NLA_NESTED Don't use `len' field -- length verification is 194 * done by checking len of nested header (or empty) 195 * NLA_NESTED_COMPAT Minimum length of structure payload 196 * NLA_U8, NLA_U16, 197 * NLA_U32, NLA_U64, 198 * NLA_S8, NLA_S16, 199 * NLA_S32, NLA_S64, 200 * NLA_MSECS Leaving the length field zero will verify the 201 * given type fits, using it verifies minimum length 202 * just like "All other" 203 * All other Minimum length of attribute payload 204 * 205 * Example: 206 * static const struct nla_policy my_policy[ATTR_MAX+1] = { 207 * [ATTR_FOO] = { .type = NLA_U16 }, 208 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, 209 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) }, 210 * }; 211 */ 212 struct nla_policy { 213 u16 type; 214 u16 len; 215 }; 216 217 /** 218 * struct nl_info - netlink source information 219 * @nlh: Netlink message header of original request 220 * @portid: Netlink PORTID of requesting application 221 */ 222 struct nl_info { 223 struct nlmsghdr *nlh; 224 struct net *nl_net; 225 u32 portid; 226 }; 227 228 int netlink_rcv_skb(struct sk_buff *skb, 229 int (*cb)(struct sk_buff *, struct nlmsghdr *)); 230 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, 231 unsigned int group, int report, gfp_t flags); 232 233 int nla_validate(const struct nlattr *head, int len, int maxtype, 234 const struct nla_policy *policy); 235 int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, 236 int len, const struct nla_policy *policy); 237 int nla_policy_len(const struct nla_policy *, int); 238 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype); 239 size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize); 240 int nla_memcpy(void *dest, const struct nlattr *src, int count); 241 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size); 242 int nla_strcmp(const struct nlattr *nla, const char *str); 243 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 244 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 245 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 246 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 247 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, 248 const void *data); 249 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 250 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); 251 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 252 int nla_append(struct sk_buff *skb, int attrlen, const void *data); 253 254 /************************************************************************** 255 * Netlink Messages 256 **************************************************************************/ 257 258 /** 259 * nlmsg_msg_size - length of netlink message not including padding 260 * @payload: length of message payload 261 */ 262 static inline int nlmsg_msg_size(int payload) 263 { 264 return NLMSG_HDRLEN + payload; 265 } 266 267 /** 268 * nlmsg_total_size - length of netlink message including padding 269 * @payload: length of message payload 270 */ 271 static inline int nlmsg_total_size(int payload) 272 { 273 return NLMSG_ALIGN(nlmsg_msg_size(payload)); 274 } 275 276 /** 277 * nlmsg_padlen - length of padding at the message's tail 278 * @payload: length of message payload 279 */ 280 static inline int nlmsg_padlen(int payload) 281 { 282 return nlmsg_total_size(payload) - nlmsg_msg_size(payload); 283 } 284 285 /** 286 * nlmsg_data - head of message payload 287 * @nlh: netlink message header 288 */ 289 static inline void *nlmsg_data(const struct nlmsghdr *nlh) 290 { 291 return (unsigned char *) nlh + NLMSG_HDRLEN; 292 } 293 294 /** 295 * nlmsg_len - length of message payload 296 * @nlh: netlink message header 297 */ 298 static inline int nlmsg_len(const struct nlmsghdr *nlh) 299 { 300 return nlh->nlmsg_len - NLMSG_HDRLEN; 301 } 302 303 /** 304 * nlmsg_attrdata - head of attributes data 305 * @nlh: netlink message header 306 * @hdrlen: length of family specific header 307 */ 308 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 309 int hdrlen) 310 { 311 unsigned char *data = nlmsg_data(nlh); 312 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); 313 } 314 315 /** 316 * nlmsg_attrlen - length of attributes data 317 * @nlh: netlink message header 318 * @hdrlen: length of family specific header 319 */ 320 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) 321 { 322 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); 323 } 324 325 /** 326 * nlmsg_ok - check if the netlink message fits into the remaining bytes 327 * @nlh: netlink message header 328 * @remaining: number of bytes remaining in message stream 329 */ 330 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) 331 { 332 return (remaining >= (int) sizeof(struct nlmsghdr) && 333 nlh->nlmsg_len >= sizeof(struct nlmsghdr) && 334 nlh->nlmsg_len <= remaining); 335 } 336 337 /** 338 * nlmsg_next - next netlink message in message stream 339 * @nlh: netlink message header 340 * @remaining: number of bytes remaining in message stream 341 * 342 * Returns the next netlink message in the message stream and 343 * decrements remaining by the size of the current message. 344 */ 345 static inline struct nlmsghdr * 346 nlmsg_next(const struct nlmsghdr *nlh, int *remaining) 347 { 348 int totlen = NLMSG_ALIGN(nlh->nlmsg_len); 349 350 *remaining -= totlen; 351 352 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); 353 } 354 355 /** 356 * nlmsg_parse - parse attributes of a netlink message 357 * @nlh: netlink message header 358 * @hdrlen: length of family specific header 359 * @tb: destination array with maxtype+1 elements 360 * @maxtype: maximum attribute type to be expected 361 * @policy: validation policy 362 * 363 * See nla_parse() 364 */ 365 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 366 struct nlattr *tb[], int maxtype, 367 const struct nla_policy *policy) 368 { 369 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 370 return -EINVAL; 371 372 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 373 nlmsg_attrlen(nlh, hdrlen), policy); 374 } 375 376 /** 377 * nlmsg_find_attr - find a specific attribute in a netlink message 378 * @nlh: netlink message header 379 * @hdrlen: length of familiy specific header 380 * @attrtype: type of attribute to look for 381 * 382 * Returns the first attribute which matches the specified type. 383 */ 384 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh, 385 int hdrlen, int attrtype) 386 { 387 return nla_find(nlmsg_attrdata(nlh, hdrlen), 388 nlmsg_attrlen(nlh, hdrlen), attrtype); 389 } 390 391 /** 392 * nlmsg_validate - validate a netlink message including attributes 393 * @nlh: netlinket message header 394 * @hdrlen: length of familiy specific header 395 * @maxtype: maximum attribute type to be expected 396 * @policy: validation policy 397 */ 398 static inline int nlmsg_validate(const struct nlmsghdr *nlh, 399 int hdrlen, int maxtype, 400 const struct nla_policy *policy) 401 { 402 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 403 return -EINVAL; 404 405 return nla_validate(nlmsg_attrdata(nlh, hdrlen), 406 nlmsg_attrlen(nlh, hdrlen), maxtype, policy); 407 } 408 409 /** 410 * nlmsg_report - need to report back to application? 411 * @nlh: netlink message header 412 * 413 * Returns 1 if a report back to the application is requested. 414 */ 415 static inline int nlmsg_report(const struct nlmsghdr *nlh) 416 { 417 return !!(nlh->nlmsg_flags & NLM_F_ECHO); 418 } 419 420 /** 421 * nlmsg_for_each_attr - iterate over a stream of attributes 422 * @pos: loop counter, set to current attribute 423 * @nlh: netlink message header 424 * @hdrlen: length of familiy specific header 425 * @rem: initialized to len, holds bytes currently remaining in stream 426 */ 427 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ 428 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ 429 nlmsg_attrlen(nlh, hdrlen), rem) 430 431 /** 432 * nlmsg_put - Add a new netlink message to an skb 433 * @skb: socket buffer to store message in 434 * @portid: netlink PORTID of requesting application 435 * @seq: sequence number of message 436 * @type: message type 437 * @payload: length of message payload 438 * @flags: message flags 439 * 440 * Returns NULL if the tailroom of the skb is insufficient to store 441 * the message header and payload. 442 */ 443 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, 444 int type, int payload, int flags) 445 { 446 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) 447 return NULL; 448 449 return __nlmsg_put(skb, portid, seq, type, payload, flags); 450 } 451 452 /** 453 * nlmsg_put_answer - Add a new callback based netlink message to an skb 454 * @skb: socket buffer to store message in 455 * @cb: netlink callback 456 * @type: message type 457 * @payload: length of message payload 458 * @flags: message flags 459 * 460 * Returns NULL if the tailroom of the skb is insufficient to store 461 * the message header and payload. 462 */ 463 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, 464 struct netlink_callback *cb, 465 int type, int payload, 466 int flags) 467 { 468 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 469 type, payload, flags); 470 } 471 472 /** 473 * nlmsg_new - Allocate a new netlink message 474 * @payload: size of the message payload 475 * @flags: the type of memory to allocate. 476 * 477 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known 478 * and a good default is needed. 479 */ 480 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) 481 { 482 return alloc_skb(nlmsg_total_size(payload), flags); 483 } 484 485 /** 486 * nlmsg_end - Finalize a netlink message 487 * @skb: socket buffer the message is stored in 488 * @nlh: netlink message header 489 * 490 * Corrects the netlink message header to include the appeneded 491 * attributes. Only necessary if attributes have been added to 492 * the message. 493 */ 494 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 495 { 496 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 497 } 498 499 /** 500 * nlmsg_get_pos - return current position in netlink message 501 * @skb: socket buffer the message is stored in 502 * 503 * Returns a pointer to the current tail of the message. 504 */ 505 static inline void *nlmsg_get_pos(struct sk_buff *skb) 506 { 507 return skb_tail_pointer(skb); 508 } 509 510 /** 511 * nlmsg_trim - Trim message to a mark 512 * @skb: socket buffer the message is stored in 513 * @mark: mark to trim to 514 * 515 * Trims the message to the provided mark. 516 */ 517 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 518 { 519 if (mark) { 520 WARN_ON((unsigned char *) mark < skb->data); 521 skb_trim(skb, (unsigned char *) mark - skb->data); 522 } 523 } 524 525 /** 526 * nlmsg_cancel - Cancel construction of a netlink message 527 * @skb: socket buffer the message is stored in 528 * @nlh: netlink message header 529 * 530 * Removes the complete netlink message including all 531 * attributes from the socket buffer again. 532 */ 533 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 534 { 535 nlmsg_trim(skb, nlh); 536 } 537 538 /** 539 * nlmsg_free - free a netlink message 540 * @skb: socket buffer of netlink message 541 */ 542 static inline void nlmsg_free(struct sk_buff *skb) 543 { 544 kfree_skb(skb); 545 } 546 547 /** 548 * nlmsg_multicast - multicast a netlink message 549 * @sk: netlink socket to spread messages to 550 * @skb: netlink message as socket buffer 551 * @portid: own netlink portid to avoid sending to yourself 552 * @group: multicast group id 553 * @flags: allocation flags 554 */ 555 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 556 u32 portid, unsigned int group, gfp_t flags) 557 { 558 int err; 559 560 NETLINK_CB(skb).dst_group = group; 561 562 err = netlink_broadcast(sk, skb, portid, group, flags); 563 if (err > 0) 564 err = 0; 565 566 return err; 567 } 568 569 /** 570 * nlmsg_unicast - unicast a netlink message 571 * @sk: netlink socket to spread message to 572 * @skb: netlink message as socket buffer 573 * @portid: netlink portid of the destination socket 574 */ 575 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid) 576 { 577 int err; 578 579 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT); 580 if (err > 0) 581 err = 0; 582 583 return err; 584 } 585 586 /** 587 * nlmsg_for_each_msg - iterate over a stream of messages 588 * @pos: loop counter, set to current message 589 * @head: head of message stream 590 * @len: length of message stream 591 * @rem: initialized to len, holds bytes currently remaining in stream 592 */ 593 #define nlmsg_for_each_msg(pos, head, len, rem) \ 594 for (pos = head, rem = len; \ 595 nlmsg_ok(pos, rem); \ 596 pos = nlmsg_next(pos, &(rem))) 597 598 /** 599 * nl_dump_check_consistent - check if sequence is consistent and advertise if not 600 * @cb: netlink callback structure that stores the sequence number 601 * @nlh: netlink message header to write the flag to 602 * 603 * This function checks if the sequence (generation) number changed during dump 604 * and if it did, advertises it in the netlink message header. 605 * 606 * The correct way to use it is to set cb->seq to the generation counter when 607 * all locks for dumping have been acquired, and then call this function for 608 * each message that is generated. 609 * 610 * Note that due to initialisation concerns, 0 is an invalid sequence number 611 * and must not be used by code that uses this functionality. 612 */ 613 static inline void 614 nl_dump_check_consistent(struct netlink_callback *cb, 615 struct nlmsghdr *nlh) 616 { 617 if (cb->prev_seq && cb->seq != cb->prev_seq) 618 nlh->nlmsg_flags |= NLM_F_DUMP_INTR; 619 cb->prev_seq = cb->seq; 620 } 621 622 /************************************************************************** 623 * Netlink Attributes 624 **************************************************************************/ 625 626 /** 627 * nla_attr_size - length of attribute not including padding 628 * @payload: length of payload 629 */ 630 static inline int nla_attr_size(int payload) 631 { 632 return NLA_HDRLEN + payload; 633 } 634 635 /** 636 * nla_total_size - total length of attribute including padding 637 * @payload: length of payload 638 */ 639 static inline int nla_total_size(int payload) 640 { 641 return NLA_ALIGN(nla_attr_size(payload)); 642 } 643 644 /** 645 * nla_padlen - length of padding at the tail of attribute 646 * @payload: length of payload 647 */ 648 static inline int nla_padlen(int payload) 649 { 650 return nla_total_size(payload) - nla_attr_size(payload); 651 } 652 653 /** 654 * nla_type - attribute type 655 * @nla: netlink attribute 656 */ 657 static inline int nla_type(const struct nlattr *nla) 658 { 659 return nla->nla_type & NLA_TYPE_MASK; 660 } 661 662 /** 663 * nla_data - head of payload 664 * @nla: netlink attribute 665 */ 666 static inline void *nla_data(const struct nlattr *nla) 667 { 668 return (char *) nla + NLA_HDRLEN; 669 } 670 671 /** 672 * nla_len - length of payload 673 * @nla: netlink attribute 674 */ 675 static inline int nla_len(const struct nlattr *nla) 676 { 677 return nla->nla_len - NLA_HDRLEN; 678 } 679 680 /** 681 * nla_ok - check if the netlink attribute fits into the remaining bytes 682 * @nla: netlink attribute 683 * @remaining: number of bytes remaining in attribute stream 684 */ 685 static inline int nla_ok(const struct nlattr *nla, int remaining) 686 { 687 return remaining >= (int) sizeof(*nla) && 688 nla->nla_len >= sizeof(*nla) && 689 nla->nla_len <= remaining; 690 } 691 692 /** 693 * nla_next - next netlink attribute in attribute stream 694 * @nla: netlink attribute 695 * @remaining: number of bytes remaining in attribute stream 696 * 697 * Returns the next netlink attribute in the attribute stream and 698 * decrements remaining by the size of the current attribute. 699 */ 700 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 701 { 702 int totlen = NLA_ALIGN(nla->nla_len); 703 704 *remaining -= totlen; 705 return (struct nlattr *) ((char *) nla + totlen); 706 } 707 708 /** 709 * nla_find_nested - find attribute in a set of nested attributes 710 * @nla: attribute containing the nested attributes 711 * @attrtype: type of attribute to look for 712 * 713 * Returns the first attribute which matches the specified type. 714 */ 715 static inline struct nlattr * 716 nla_find_nested(const struct nlattr *nla, int attrtype) 717 { 718 return nla_find(nla_data(nla), nla_len(nla), attrtype); 719 } 720 721 /** 722 * nla_parse_nested - parse nested attributes 723 * @tb: destination array with maxtype+1 elements 724 * @maxtype: maximum attribute type to be expected 725 * @nla: attribute containing the nested attributes 726 * @policy: validation policy 727 * 728 * See nla_parse() 729 */ 730 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 731 const struct nlattr *nla, 732 const struct nla_policy *policy) 733 { 734 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); 735 } 736 737 /** 738 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 739 * @skb: socket buffer to add attribute to 740 * @attrtype: attribute type 741 * @value: numeric value 742 */ 743 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 744 { 745 return nla_put(skb, attrtype, sizeof(u8), &value); 746 } 747 748 /** 749 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer 750 * @skb: socket buffer to add attribute to 751 * @attrtype: attribute type 752 * @value: numeric value 753 */ 754 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) 755 { 756 return nla_put(skb, attrtype, sizeof(u16), &value); 757 } 758 759 /** 760 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer 761 * @skb: socket buffer to add attribute to 762 * @attrtype: attribute type 763 * @value: numeric value 764 */ 765 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value) 766 { 767 return nla_put(skb, attrtype, sizeof(__be16), &value); 768 } 769 770 /** 771 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer 772 * @skb: socket buffer to add attribute to 773 * @attrtype: attribute type 774 * @value: numeric value 775 */ 776 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value) 777 { 778 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, value); 779 } 780 781 /** 782 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer 783 * @skb: socket buffer to add attribute to 784 * @attrtype: attribute type 785 * @value: numeric value 786 */ 787 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value) 788 { 789 return nla_put(skb, attrtype, sizeof(__le16), &value); 790 } 791 792 /** 793 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 794 * @skb: socket buffer to add attribute to 795 * @attrtype: attribute type 796 * @value: numeric value 797 */ 798 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 799 { 800 return nla_put(skb, attrtype, sizeof(u32), &value); 801 } 802 803 /** 804 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer 805 * @skb: socket buffer to add attribute to 806 * @attrtype: attribute type 807 * @value: numeric value 808 */ 809 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value) 810 { 811 return nla_put(skb, attrtype, sizeof(__be32), &value); 812 } 813 814 /** 815 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer 816 * @skb: socket buffer to add attribute to 817 * @attrtype: attribute type 818 * @value: numeric value 819 */ 820 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value) 821 { 822 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, value); 823 } 824 825 /** 826 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer 827 * @skb: socket buffer to add attribute to 828 * @attrtype: attribute type 829 * @value: numeric value 830 */ 831 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value) 832 { 833 return nla_put(skb, attrtype, sizeof(__le32), &value); 834 } 835 836 /** 837 * nla_put_u64 - Add a u64 netlink attribute to a socket buffer 838 * @skb: socket buffer to add attribute to 839 * @attrtype: attribute type 840 * @value: numeric value 841 */ 842 static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value) 843 { 844 return nla_put(skb, attrtype, sizeof(u64), &value); 845 } 846 847 /** 848 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer 849 * @skb: socket buffer to add attribute to 850 * @attrtype: attribute type 851 * @value: numeric value 852 */ 853 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value) 854 { 855 return nla_put(skb, attrtype, sizeof(__be64), &value); 856 } 857 858 /** 859 * nla_put_net64 - Add 64-bit network byte order netlink attribute to a socket buffer 860 * @skb: socket buffer to add attribute to 861 * @attrtype: attribute type 862 * @value: numeric value 863 */ 864 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value) 865 { 866 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, value); 867 } 868 869 /** 870 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer 871 * @skb: socket buffer to add attribute to 872 * @attrtype: attribute type 873 * @value: numeric value 874 */ 875 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value) 876 { 877 return nla_put(skb, attrtype, sizeof(__le64), &value); 878 } 879 880 /** 881 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer 882 * @skb: socket buffer to add attribute to 883 * @attrtype: attribute type 884 * @value: numeric value 885 */ 886 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value) 887 { 888 return nla_put(skb, attrtype, sizeof(s8), &value); 889 } 890 891 /** 892 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer 893 * @skb: socket buffer to add attribute to 894 * @attrtype: attribute type 895 * @value: numeric value 896 */ 897 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value) 898 { 899 return nla_put(skb, attrtype, sizeof(s16), &value); 900 } 901 902 /** 903 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer 904 * @skb: socket buffer to add attribute to 905 * @attrtype: attribute type 906 * @value: numeric value 907 */ 908 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value) 909 { 910 return nla_put(skb, attrtype, sizeof(s32), &value); 911 } 912 913 /** 914 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer 915 * @skb: socket buffer to add attribute to 916 * @attrtype: attribute type 917 * @value: numeric value 918 */ 919 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value) 920 { 921 return nla_put(skb, attrtype, sizeof(s64), &value); 922 } 923 924 /** 925 * nla_put_string - Add a string netlink attribute to a socket buffer 926 * @skb: socket buffer to add attribute to 927 * @attrtype: attribute type 928 * @str: NUL terminated string 929 */ 930 static inline int nla_put_string(struct sk_buff *skb, int attrtype, 931 const char *str) 932 { 933 return nla_put(skb, attrtype, strlen(str) + 1, str); 934 } 935 936 /** 937 * nla_put_flag - Add a flag netlink attribute to a socket buffer 938 * @skb: socket buffer to add attribute to 939 * @attrtype: attribute type 940 */ 941 static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 942 { 943 return nla_put(skb, attrtype, 0, NULL); 944 } 945 946 /** 947 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer 948 * @skb: socket buffer to add attribute to 949 * @attrtype: attribute type 950 * @njiffies: number of jiffies to convert to msecs 951 */ 952 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 953 unsigned long njiffies) 954 { 955 u64 tmp = jiffies_to_msecs(njiffies); 956 return nla_put(skb, attrtype, sizeof(u64), &tmp); 957 } 958 959 /** 960 * nla_get_u32 - return payload of u32 attribute 961 * @nla: u32 netlink attribute 962 */ 963 static inline u32 nla_get_u32(const struct nlattr *nla) 964 { 965 return *(u32 *) nla_data(nla); 966 } 967 968 /** 969 * nla_get_be32 - return payload of __be32 attribute 970 * @nla: __be32 netlink attribute 971 */ 972 static inline __be32 nla_get_be32(const struct nlattr *nla) 973 { 974 return *(__be32 *) nla_data(nla); 975 } 976 977 /** 978 * nla_get_u16 - return payload of u16 attribute 979 * @nla: u16 netlink attribute 980 */ 981 static inline u16 nla_get_u16(const struct nlattr *nla) 982 { 983 return *(u16 *) nla_data(nla); 984 } 985 986 /** 987 * nla_get_be16 - return payload of __be16 attribute 988 * @nla: __be16 netlink attribute 989 */ 990 static inline __be16 nla_get_be16(const struct nlattr *nla) 991 { 992 return *(__be16 *) nla_data(nla); 993 } 994 995 /** 996 * nla_get_le16 - return payload of __le16 attribute 997 * @nla: __le16 netlink attribute 998 */ 999 static inline __le16 nla_get_le16(const struct nlattr *nla) 1000 { 1001 return *(__le16 *) nla_data(nla); 1002 } 1003 1004 /** 1005 * nla_get_u8 - return payload of u8 attribute 1006 * @nla: u8 netlink attribute 1007 */ 1008 static inline u8 nla_get_u8(const struct nlattr *nla) 1009 { 1010 return *(u8 *) nla_data(nla); 1011 } 1012 1013 /** 1014 * nla_get_u64 - return payload of u64 attribute 1015 * @nla: u64 netlink attribute 1016 */ 1017 static inline u64 nla_get_u64(const struct nlattr *nla) 1018 { 1019 u64 tmp; 1020 1021 nla_memcpy(&tmp, nla, sizeof(tmp)); 1022 1023 return tmp; 1024 } 1025 1026 /** 1027 * nla_get_be64 - return payload of __be64 attribute 1028 * @nla: __be64 netlink attribute 1029 */ 1030 static inline __be64 nla_get_be64(const struct nlattr *nla) 1031 { 1032 __be64 tmp; 1033 1034 nla_memcpy(&tmp, nla, sizeof(tmp)); 1035 1036 return tmp; 1037 } 1038 1039 /** 1040 * nla_get_s32 - return payload of s32 attribute 1041 * @nla: s32 netlink attribute 1042 */ 1043 static inline s32 nla_get_s32(const struct nlattr *nla) 1044 { 1045 return *(s32 *) nla_data(nla); 1046 } 1047 1048 /** 1049 * nla_get_s16 - return payload of s16 attribute 1050 * @nla: s16 netlink attribute 1051 */ 1052 static inline s16 nla_get_s16(const struct nlattr *nla) 1053 { 1054 return *(s16 *) nla_data(nla); 1055 } 1056 1057 /** 1058 * nla_get_s8 - return payload of s8 attribute 1059 * @nla: s8 netlink attribute 1060 */ 1061 static inline s8 nla_get_s8(const struct nlattr *nla) 1062 { 1063 return *(s8 *) nla_data(nla); 1064 } 1065 1066 /** 1067 * nla_get_s64 - return payload of s64 attribute 1068 * @nla: s64 netlink attribute 1069 */ 1070 static inline s64 nla_get_s64(const struct nlattr *nla) 1071 { 1072 s64 tmp; 1073 1074 nla_memcpy(&tmp, nla, sizeof(tmp)); 1075 1076 return tmp; 1077 } 1078 1079 /** 1080 * nla_get_flag - return payload of flag attribute 1081 * @nla: flag netlink attribute 1082 */ 1083 static inline int nla_get_flag(const struct nlattr *nla) 1084 { 1085 return !!nla; 1086 } 1087 1088 /** 1089 * nla_get_msecs - return payload of msecs attribute 1090 * @nla: msecs netlink attribute 1091 * 1092 * Returns the number of milliseconds in jiffies. 1093 */ 1094 static inline unsigned long nla_get_msecs(const struct nlattr *nla) 1095 { 1096 u64 msecs = nla_get_u64(nla); 1097 1098 return msecs_to_jiffies((unsigned long) msecs); 1099 } 1100 1101 /** 1102 * nla_nest_start - Start a new level of nested attributes 1103 * @skb: socket buffer to add attributes to 1104 * @attrtype: attribute type of container 1105 * 1106 * Returns the container attribute 1107 */ 1108 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 1109 { 1110 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 1111 1112 if (nla_put(skb, attrtype, 0, NULL) < 0) 1113 return NULL; 1114 1115 return start; 1116 } 1117 1118 /** 1119 * nla_nest_end - Finalize nesting of attributes 1120 * @skb: socket buffer the attributes are stored in 1121 * @start: container attribute 1122 * 1123 * Corrects the container attribute header to include the all 1124 * appeneded attributes. 1125 * 1126 * Returns the total data length of the skb. 1127 */ 1128 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 1129 { 1130 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1131 return skb->len; 1132 } 1133 1134 /** 1135 * nla_nest_cancel - Cancel nesting of attributes 1136 * @skb: socket buffer the message is stored in 1137 * @start: container attribute 1138 * 1139 * Removes the container attribute and including all nested 1140 * attributes. Returns -EMSGSIZE 1141 */ 1142 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 1143 { 1144 nlmsg_trim(skb, start); 1145 } 1146 1147 /** 1148 * nla_validate_nested - Validate a stream of nested attributes 1149 * @start: container attribute 1150 * @maxtype: maximum attribute type to be expected 1151 * @policy: validation policy 1152 * 1153 * Validates all attributes in the nested attribute stream against the 1154 * specified policy. Attributes with a type exceeding maxtype will be 1155 * ignored. See documenation of struct nla_policy for more details. 1156 * 1157 * Returns 0 on success or a negative error code. 1158 */ 1159 static inline int nla_validate_nested(const struct nlattr *start, int maxtype, 1160 const struct nla_policy *policy) 1161 { 1162 return nla_validate(nla_data(start), nla_len(start), maxtype, policy); 1163 } 1164 1165 /** 1166 * nla_for_each_attr - iterate over a stream of attributes 1167 * @pos: loop counter, set to current attribute 1168 * @head: head of attribute stream 1169 * @len: length of attribute stream 1170 * @rem: initialized to len, holds bytes currently remaining in stream 1171 */ 1172 #define nla_for_each_attr(pos, head, len, rem) \ 1173 for (pos = head, rem = len; \ 1174 nla_ok(pos, rem); \ 1175 pos = nla_next(pos, &(rem))) 1176 1177 /** 1178 * nla_for_each_nested - iterate over nested attributes 1179 * @pos: loop counter, set to current attribute 1180 * @nla: attribute containing the nested attributes 1181 * @rem: initialized to len, holds bytes currently remaining in stream 1182 */ 1183 #define nla_for_each_nested(pos, nla, rem) \ 1184 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 1185 1186 /** 1187 * nla_is_last - Test if attribute is last in stream 1188 * @nla: attribute to test 1189 * @rem: bytes remaining in stream 1190 */ 1191 static inline bool nla_is_last(const struct nlattr *nla, int rem) 1192 { 1193 return nla->nla_len == rem; 1194 } 1195 1196 #endif 1197