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 * Returns the total data length of the skb. 495 */ 496 static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 497 { 498 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 499 500 return skb->len; 501 } 502 503 /** 504 * nlmsg_get_pos - return current position in netlink message 505 * @skb: socket buffer the message is stored in 506 * 507 * Returns a pointer to the current tail of the message. 508 */ 509 static inline void *nlmsg_get_pos(struct sk_buff *skb) 510 { 511 return skb_tail_pointer(skb); 512 } 513 514 /** 515 * nlmsg_trim - Trim message to a mark 516 * @skb: socket buffer the message is stored in 517 * @mark: mark to trim to 518 * 519 * Trims the message to the provided mark. 520 */ 521 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 522 { 523 if (mark) 524 skb_trim(skb, (unsigned char *) mark - skb->data); 525 } 526 527 /** 528 * nlmsg_cancel - Cancel construction of a netlink message 529 * @skb: socket buffer the message is stored in 530 * @nlh: netlink message header 531 * 532 * Removes the complete netlink message including all 533 * attributes from the socket buffer again. 534 */ 535 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 536 { 537 nlmsg_trim(skb, nlh); 538 } 539 540 /** 541 * nlmsg_free - free a netlink message 542 * @skb: socket buffer of netlink message 543 */ 544 static inline void nlmsg_free(struct sk_buff *skb) 545 { 546 kfree_skb(skb); 547 } 548 549 /** 550 * nlmsg_multicast - multicast a netlink message 551 * @sk: netlink socket to spread messages to 552 * @skb: netlink message as socket buffer 553 * @portid: own netlink portid to avoid sending to yourself 554 * @group: multicast group id 555 * @flags: allocation flags 556 */ 557 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 558 u32 portid, unsigned int group, gfp_t flags) 559 { 560 int err; 561 562 NETLINK_CB(skb).dst_group = group; 563 564 err = netlink_broadcast(sk, skb, portid, group, flags); 565 if (err > 0) 566 err = 0; 567 568 return err; 569 } 570 571 /** 572 * nlmsg_unicast - unicast a netlink message 573 * @sk: netlink socket to spread message to 574 * @skb: netlink message as socket buffer 575 * @portid: netlink portid of the destination socket 576 */ 577 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid) 578 { 579 int err; 580 581 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT); 582 if (err > 0) 583 err = 0; 584 585 return err; 586 } 587 588 /** 589 * nlmsg_for_each_msg - iterate over a stream of messages 590 * @pos: loop counter, set to current message 591 * @head: head of message stream 592 * @len: length of message stream 593 * @rem: initialized to len, holds bytes currently remaining in stream 594 */ 595 #define nlmsg_for_each_msg(pos, head, len, rem) \ 596 for (pos = head, rem = len; \ 597 nlmsg_ok(pos, rem); \ 598 pos = nlmsg_next(pos, &(rem))) 599 600 /** 601 * nl_dump_check_consistent - check if sequence is consistent and advertise if not 602 * @cb: netlink callback structure that stores the sequence number 603 * @nlh: netlink message header to write the flag to 604 * 605 * This function checks if the sequence (generation) number changed during dump 606 * and if it did, advertises it in the netlink message header. 607 * 608 * The correct way to use it is to set cb->seq to the generation counter when 609 * all locks for dumping have been acquired, and then call this function for 610 * each message that is generated. 611 * 612 * Note that due to initialisation concerns, 0 is an invalid sequence number 613 * and must not be used by code that uses this functionality. 614 */ 615 static inline void 616 nl_dump_check_consistent(struct netlink_callback *cb, 617 struct nlmsghdr *nlh) 618 { 619 if (cb->prev_seq && cb->seq != cb->prev_seq) 620 nlh->nlmsg_flags |= NLM_F_DUMP_INTR; 621 cb->prev_seq = cb->seq; 622 } 623 624 /************************************************************************** 625 * Netlink Attributes 626 **************************************************************************/ 627 628 /** 629 * nla_attr_size - length of attribute not including padding 630 * @payload: length of payload 631 */ 632 static inline int nla_attr_size(int payload) 633 { 634 return NLA_HDRLEN + payload; 635 } 636 637 /** 638 * nla_total_size - total length of attribute including padding 639 * @payload: length of payload 640 */ 641 static inline int nla_total_size(int payload) 642 { 643 return NLA_ALIGN(nla_attr_size(payload)); 644 } 645 646 /** 647 * nla_padlen - length of padding at the tail of attribute 648 * @payload: length of payload 649 */ 650 static inline int nla_padlen(int payload) 651 { 652 return nla_total_size(payload) - nla_attr_size(payload); 653 } 654 655 /** 656 * nla_type - attribute type 657 * @nla: netlink attribute 658 */ 659 static inline int nla_type(const struct nlattr *nla) 660 { 661 return nla->nla_type & NLA_TYPE_MASK; 662 } 663 664 /** 665 * nla_data - head of payload 666 * @nla: netlink attribute 667 */ 668 static inline void *nla_data(const struct nlattr *nla) 669 { 670 return (char *) nla + NLA_HDRLEN; 671 } 672 673 /** 674 * nla_len - length of payload 675 * @nla: netlink attribute 676 */ 677 static inline int nla_len(const struct nlattr *nla) 678 { 679 return nla->nla_len - NLA_HDRLEN; 680 } 681 682 /** 683 * nla_ok - check if the netlink attribute fits into the remaining bytes 684 * @nla: netlink attribute 685 * @remaining: number of bytes remaining in attribute stream 686 */ 687 static inline int nla_ok(const struct nlattr *nla, int remaining) 688 { 689 return remaining >= (int) sizeof(*nla) && 690 nla->nla_len >= sizeof(*nla) && 691 nla->nla_len <= remaining; 692 } 693 694 /** 695 * nla_next - next netlink attribute in attribute stream 696 * @nla: netlink attribute 697 * @remaining: number of bytes remaining in attribute stream 698 * 699 * Returns the next netlink attribute in the attribute stream and 700 * decrements remaining by the size of the current attribute. 701 */ 702 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 703 { 704 int totlen = NLA_ALIGN(nla->nla_len); 705 706 *remaining -= totlen; 707 return (struct nlattr *) ((char *) nla + totlen); 708 } 709 710 /** 711 * nla_find_nested - find attribute in a set of nested attributes 712 * @nla: attribute containing the nested attributes 713 * @attrtype: type of attribute to look for 714 * 715 * Returns the first attribute which matches the specified type. 716 */ 717 static inline struct nlattr * 718 nla_find_nested(const struct nlattr *nla, int attrtype) 719 { 720 return nla_find(nla_data(nla), nla_len(nla), attrtype); 721 } 722 723 /** 724 * nla_parse_nested - parse nested attributes 725 * @tb: destination array with maxtype+1 elements 726 * @maxtype: maximum attribute type to be expected 727 * @nla: attribute containing the nested attributes 728 * @policy: validation policy 729 * 730 * See nla_parse() 731 */ 732 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 733 const struct nlattr *nla, 734 const struct nla_policy *policy) 735 { 736 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); 737 } 738 739 /** 740 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 741 * @skb: socket buffer to add attribute to 742 * @attrtype: attribute type 743 * @value: numeric value 744 */ 745 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 746 { 747 return nla_put(skb, attrtype, sizeof(u8), &value); 748 } 749 750 /** 751 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer 752 * @skb: socket buffer to add attribute to 753 * @attrtype: attribute type 754 * @value: numeric value 755 */ 756 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) 757 { 758 return nla_put(skb, attrtype, sizeof(u16), &value); 759 } 760 761 /** 762 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer 763 * @skb: socket buffer to add attribute to 764 * @attrtype: attribute type 765 * @value: numeric value 766 */ 767 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value) 768 { 769 return nla_put(skb, attrtype, sizeof(__be16), &value); 770 } 771 772 /** 773 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer 774 * @skb: socket buffer to add attribute to 775 * @attrtype: attribute type 776 * @value: numeric value 777 */ 778 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value) 779 { 780 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, value); 781 } 782 783 /** 784 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer 785 * @skb: socket buffer to add attribute to 786 * @attrtype: attribute type 787 * @value: numeric value 788 */ 789 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value) 790 { 791 return nla_put(skb, attrtype, sizeof(__le16), &value); 792 } 793 794 /** 795 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 796 * @skb: socket buffer to add attribute to 797 * @attrtype: attribute type 798 * @value: numeric value 799 */ 800 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 801 { 802 return nla_put(skb, attrtype, sizeof(u32), &value); 803 } 804 805 /** 806 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer 807 * @skb: socket buffer to add attribute to 808 * @attrtype: attribute type 809 * @value: numeric value 810 */ 811 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value) 812 { 813 return nla_put(skb, attrtype, sizeof(__be32), &value); 814 } 815 816 /** 817 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer 818 * @skb: socket buffer to add attribute to 819 * @attrtype: attribute type 820 * @value: numeric value 821 */ 822 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value) 823 { 824 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, value); 825 } 826 827 /** 828 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer 829 * @skb: socket buffer to add attribute to 830 * @attrtype: attribute type 831 * @value: numeric value 832 */ 833 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value) 834 { 835 return nla_put(skb, attrtype, sizeof(__le32), &value); 836 } 837 838 /** 839 * nla_put_u64 - Add a u64 netlink attribute to a socket buffer 840 * @skb: socket buffer to add attribute to 841 * @attrtype: attribute type 842 * @value: numeric value 843 */ 844 static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value) 845 { 846 return nla_put(skb, attrtype, sizeof(u64), &value); 847 } 848 849 /** 850 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer 851 * @skb: socket buffer to add attribute to 852 * @attrtype: attribute type 853 * @value: numeric value 854 */ 855 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value) 856 { 857 return nla_put(skb, attrtype, sizeof(__be64), &value); 858 } 859 860 /** 861 * nla_put_net64 - Add 64-bit network byte order netlink attribute to a socket buffer 862 * @skb: socket buffer to add attribute to 863 * @attrtype: attribute type 864 * @value: numeric value 865 */ 866 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value) 867 { 868 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, value); 869 } 870 871 /** 872 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer 873 * @skb: socket buffer to add attribute to 874 * @attrtype: attribute type 875 * @value: numeric value 876 */ 877 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value) 878 { 879 return nla_put(skb, attrtype, sizeof(__le64), &value); 880 } 881 882 /** 883 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer 884 * @skb: socket buffer to add attribute to 885 * @attrtype: attribute type 886 * @value: numeric value 887 */ 888 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value) 889 { 890 return nla_put(skb, attrtype, sizeof(s8), &value); 891 } 892 893 /** 894 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer 895 * @skb: socket buffer to add attribute to 896 * @attrtype: attribute type 897 * @value: numeric value 898 */ 899 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value) 900 { 901 return nla_put(skb, attrtype, sizeof(s16), &value); 902 } 903 904 /** 905 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer 906 * @skb: socket buffer to add attribute to 907 * @attrtype: attribute type 908 * @value: numeric value 909 */ 910 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value) 911 { 912 return nla_put(skb, attrtype, sizeof(s32), &value); 913 } 914 915 /** 916 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer 917 * @skb: socket buffer to add attribute to 918 * @attrtype: attribute type 919 * @value: numeric value 920 */ 921 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value) 922 { 923 return nla_put(skb, attrtype, sizeof(s64), &value); 924 } 925 926 /** 927 * nla_put_string - Add a string netlink attribute to a socket buffer 928 * @skb: socket buffer to add attribute to 929 * @attrtype: attribute type 930 * @str: NUL terminated string 931 */ 932 static inline int nla_put_string(struct sk_buff *skb, int attrtype, 933 const char *str) 934 { 935 return nla_put(skb, attrtype, strlen(str) + 1, str); 936 } 937 938 /** 939 * nla_put_flag - Add a flag netlink attribute to a socket buffer 940 * @skb: socket buffer to add attribute to 941 * @attrtype: attribute type 942 */ 943 static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 944 { 945 return nla_put(skb, attrtype, 0, NULL); 946 } 947 948 /** 949 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer 950 * @skb: socket buffer to add attribute to 951 * @attrtype: attribute type 952 * @njiffies: number of jiffies to convert to msecs 953 */ 954 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 955 unsigned long njiffies) 956 { 957 u64 tmp = jiffies_to_msecs(njiffies); 958 return nla_put(skb, attrtype, sizeof(u64), &tmp); 959 } 960 961 /** 962 * nla_get_u32 - return payload of u32 attribute 963 * @nla: u32 netlink attribute 964 */ 965 static inline u32 nla_get_u32(const struct nlattr *nla) 966 { 967 return *(u32 *) nla_data(nla); 968 } 969 970 /** 971 * nla_get_be32 - return payload of __be32 attribute 972 * @nla: __be32 netlink attribute 973 */ 974 static inline __be32 nla_get_be32(const struct nlattr *nla) 975 { 976 return *(__be32 *) nla_data(nla); 977 } 978 979 /** 980 * nla_get_u16 - return payload of u16 attribute 981 * @nla: u16 netlink attribute 982 */ 983 static inline u16 nla_get_u16(const struct nlattr *nla) 984 { 985 return *(u16 *) nla_data(nla); 986 } 987 988 /** 989 * nla_get_be16 - return payload of __be16 attribute 990 * @nla: __be16 netlink attribute 991 */ 992 static inline __be16 nla_get_be16(const struct nlattr *nla) 993 { 994 return *(__be16 *) nla_data(nla); 995 } 996 997 /** 998 * nla_get_le16 - return payload of __le16 attribute 999 * @nla: __le16 netlink attribute 1000 */ 1001 static inline __le16 nla_get_le16(const struct nlattr *nla) 1002 { 1003 return *(__le16 *) nla_data(nla); 1004 } 1005 1006 /** 1007 * nla_get_u8 - return payload of u8 attribute 1008 * @nla: u8 netlink attribute 1009 */ 1010 static inline u8 nla_get_u8(const struct nlattr *nla) 1011 { 1012 return *(u8 *) nla_data(nla); 1013 } 1014 1015 /** 1016 * nla_get_u64 - return payload of u64 attribute 1017 * @nla: u64 netlink attribute 1018 */ 1019 static inline u64 nla_get_u64(const struct nlattr *nla) 1020 { 1021 u64 tmp; 1022 1023 nla_memcpy(&tmp, nla, sizeof(tmp)); 1024 1025 return tmp; 1026 } 1027 1028 /** 1029 * nla_get_be64 - return payload of __be64 attribute 1030 * @nla: __be64 netlink attribute 1031 */ 1032 static inline __be64 nla_get_be64(const struct nlattr *nla) 1033 { 1034 __be64 tmp; 1035 1036 nla_memcpy(&tmp, nla, sizeof(tmp)); 1037 1038 return tmp; 1039 } 1040 1041 /** 1042 * nla_get_s32 - return payload of s32 attribute 1043 * @nla: s32 netlink attribute 1044 */ 1045 static inline s32 nla_get_s32(const struct nlattr *nla) 1046 { 1047 return *(s32 *) nla_data(nla); 1048 } 1049 1050 /** 1051 * nla_get_s16 - return payload of s16 attribute 1052 * @nla: s16 netlink attribute 1053 */ 1054 static inline s16 nla_get_s16(const struct nlattr *nla) 1055 { 1056 return *(s16 *) nla_data(nla); 1057 } 1058 1059 /** 1060 * nla_get_s8 - return payload of s8 attribute 1061 * @nla: s8 netlink attribute 1062 */ 1063 static inline s8 nla_get_s8(const struct nlattr *nla) 1064 { 1065 return *(s8 *) nla_data(nla); 1066 } 1067 1068 /** 1069 * nla_get_s64 - return payload of s64 attribute 1070 * @nla: s64 netlink attribute 1071 */ 1072 static inline s64 nla_get_s64(const struct nlattr *nla) 1073 { 1074 s64 tmp; 1075 1076 nla_memcpy(&tmp, nla, sizeof(tmp)); 1077 1078 return tmp; 1079 } 1080 1081 /** 1082 * nla_get_flag - return payload of flag attribute 1083 * @nla: flag netlink attribute 1084 */ 1085 static inline int nla_get_flag(const struct nlattr *nla) 1086 { 1087 return !!nla; 1088 } 1089 1090 /** 1091 * nla_get_msecs - return payload of msecs attribute 1092 * @nla: msecs netlink attribute 1093 * 1094 * Returns the number of milliseconds in jiffies. 1095 */ 1096 static inline unsigned long nla_get_msecs(const struct nlattr *nla) 1097 { 1098 u64 msecs = nla_get_u64(nla); 1099 1100 return msecs_to_jiffies((unsigned long) msecs); 1101 } 1102 1103 /** 1104 * nla_nest_start - Start a new level of nested attributes 1105 * @skb: socket buffer to add attributes to 1106 * @attrtype: attribute type of container 1107 * 1108 * Returns the container attribute 1109 */ 1110 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 1111 { 1112 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 1113 1114 if (nla_put(skb, attrtype, 0, NULL) < 0) 1115 return NULL; 1116 1117 return start; 1118 } 1119 1120 /** 1121 * nla_nest_end - Finalize nesting of attributes 1122 * @skb: socket buffer the attributes are stored in 1123 * @start: container attribute 1124 * 1125 * Corrects the container attribute header to include the all 1126 * appeneded attributes. 1127 * 1128 * Returns the total data length of the skb. 1129 */ 1130 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 1131 { 1132 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1133 return skb->len; 1134 } 1135 1136 /** 1137 * nla_nest_cancel - Cancel nesting of attributes 1138 * @skb: socket buffer the message is stored in 1139 * @start: container attribute 1140 * 1141 * Removes the container attribute and including all nested 1142 * attributes. Returns -EMSGSIZE 1143 */ 1144 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 1145 { 1146 nlmsg_trim(skb, start); 1147 } 1148 1149 /** 1150 * nla_validate_nested - Validate a stream of nested attributes 1151 * @start: container attribute 1152 * @maxtype: maximum attribute type to be expected 1153 * @policy: validation policy 1154 * 1155 * Validates all attributes in the nested attribute stream against the 1156 * specified policy. Attributes with a type exceeding maxtype will be 1157 * ignored. See documenation of struct nla_policy for more details. 1158 * 1159 * Returns 0 on success or a negative error code. 1160 */ 1161 static inline int nla_validate_nested(const struct nlattr *start, int maxtype, 1162 const struct nla_policy *policy) 1163 { 1164 return nla_validate(nla_data(start), nla_len(start), maxtype, policy); 1165 } 1166 1167 /** 1168 * nla_for_each_attr - iterate over a stream of attributes 1169 * @pos: loop counter, set to current attribute 1170 * @head: head of attribute stream 1171 * @len: length of attribute stream 1172 * @rem: initialized to len, holds bytes currently remaining in stream 1173 */ 1174 #define nla_for_each_attr(pos, head, len, rem) \ 1175 for (pos = head, rem = len; \ 1176 nla_ok(pos, rem); \ 1177 pos = nla_next(pos, &(rem))) 1178 1179 /** 1180 * nla_for_each_nested - iterate over nested attributes 1181 * @pos: loop counter, set to current attribute 1182 * @nla: attribute containing the nested attributes 1183 * @rem: initialized to len, holds bytes currently remaining in stream 1184 */ 1185 #define nla_for_each_nested(pos, nla, rem) \ 1186 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 1187 1188 #endif 1189