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 #include <linux/in6.h> 8 9 /* ======================================================================== 10 * Netlink Messages and Attributes Interface (As Seen On TV) 11 * ------------------------------------------------------------------------ 12 * Messages Interface 13 * ------------------------------------------------------------------------ 14 * 15 * Message Format: 16 * <--- nlmsg_total_size(payload) ---> 17 * <-- nlmsg_msg_size(payload) -> 18 * +----------+- - -+-------------+- - -+-------- - - 19 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr 20 * +----------+- - -+-------------+- - -+-------- - - 21 * nlmsg_data(nlh)---^ ^ 22 * nlmsg_next(nlh)-----------------------+ 23 * 24 * Payload Format: 25 * <---------------------- nlmsg_len(nlh) ---------------------> 26 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) -> 27 * +----------------------+- - -+--------------------------------+ 28 * | Family Header | Pad | Attributes | 29 * +----------------------+- - -+--------------------------------+ 30 * nlmsg_attrdata(nlh, hdrlen)---^ 31 * 32 * Data Structures: 33 * struct nlmsghdr netlink message header 34 * 35 * Message Construction: 36 * nlmsg_new() create a new netlink message 37 * nlmsg_put() add a netlink message to an skb 38 * nlmsg_put_answer() callback based nlmsg_put() 39 * nlmsg_end() finalize netlink message 40 * nlmsg_get_pos() return current position in message 41 * nlmsg_trim() trim part of message 42 * nlmsg_cancel() cancel message construction 43 * nlmsg_free() free a netlink message 44 * 45 * Message Sending: 46 * nlmsg_multicast() multicast message to several groups 47 * nlmsg_unicast() unicast a message to a single socket 48 * nlmsg_notify() send notification message 49 * 50 * Message Length Calculations: 51 * nlmsg_msg_size(payload) length of message w/o padding 52 * nlmsg_total_size(payload) length of message w/ padding 53 * nlmsg_padlen(payload) length of padding at tail 54 * 55 * Message Payload Access: 56 * nlmsg_data(nlh) head of message payload 57 * nlmsg_len(nlh) length of message payload 58 * nlmsg_attrdata(nlh, hdrlen) head of attributes data 59 * nlmsg_attrlen(nlh, hdrlen) length of attributes data 60 * 61 * Message Parsing: 62 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes? 63 * nlmsg_next(nlh, remaining) get next netlink message 64 * nlmsg_parse() parse attributes of a message 65 * nlmsg_find_attr() find an attribute in a message 66 * nlmsg_for_each_msg() loop over all messages 67 * nlmsg_validate() validate netlink message incl. attrs 68 * nlmsg_for_each_attr() loop over all attributes 69 * 70 * Misc: 71 * nlmsg_report() report back to application? 72 * 73 * ------------------------------------------------------------------------ 74 * Attributes Interface 75 * ------------------------------------------------------------------------ 76 * 77 * Attribute Format: 78 * <------- nla_total_size(payload) -------> 79 * <---- nla_attr_size(payload) -----> 80 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 81 * | Header | Pad | Payload | Pad | Header 82 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 83 * <- nla_len(nla) -> ^ 84 * nla_data(nla)----^ | 85 * nla_next(nla)-----------------------------' 86 * 87 * Data Structures: 88 * struct nlattr netlink attribute header 89 * 90 * Attribute Construction: 91 * nla_reserve(skb, type, len) reserve room for an attribute 92 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr 93 * nla_put(skb, type, len, data) add attribute to skb 94 * nla_put_nohdr(skb, len, data) add attribute w/o hdr 95 * nla_append(skb, len, data) append data to skb 96 * 97 * Attribute Construction for Basic Types: 98 * nla_put_u8(skb, type, value) add u8 attribute to skb 99 * nla_put_u16(skb, type, value) add u16 attribute to skb 100 * nla_put_u32(skb, type, value) add u32 attribute to skb 101 * nla_put_u64(skb, type, value) add u64 attribute to skb 102 * nla_put_s8(skb, type, value) add s8 attribute to skb 103 * nla_put_s16(skb, type, value) add s16 attribute to skb 104 * nla_put_s32(skb, type, value) add s32 attribute to skb 105 * nla_put_s64(skb, type, value) add s64 attribute to skb 106 * nla_put_string(skb, type, str) add string attribute to skb 107 * nla_put_flag(skb, type) add flag attribute to skb 108 * nla_put_msecs(skb, type, jiffies) add msecs attribute to skb 109 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb 110 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb 111 * 112 * Nested Attributes Construction: 113 * nla_nest_start(skb, type) start a nested attribute 114 * nla_nest_end(skb, nla) finalize a nested attribute 115 * nla_nest_cancel(skb, nla) cancel nested attribute construction 116 * 117 * Attribute Length Calculations: 118 * nla_attr_size(payload) length of attribute w/o padding 119 * nla_total_size(payload) length of attribute w/ padding 120 * nla_padlen(payload) length of padding 121 * 122 * Attribute Payload Access: 123 * nla_data(nla) head of attribute payload 124 * nla_len(nla) length of attribute payload 125 * 126 * Attribute Payload Access for Basic Types: 127 * nla_get_u8(nla) get payload for a u8 attribute 128 * nla_get_u16(nla) get payload for a u16 attribute 129 * nla_get_u32(nla) get payload for a u32 attribute 130 * nla_get_u64(nla) get payload for a u64 attribute 131 * nla_get_s8(nla) get payload for a s8 attribute 132 * nla_get_s16(nla) get payload for a s16 attribute 133 * nla_get_s32(nla) get payload for a s32 attribute 134 * nla_get_s64(nla) get payload for a s64 attribute 135 * nla_get_flag(nla) return 1 if flag is true 136 * nla_get_msecs(nla) get payload for a msecs attribute 137 * 138 * Attribute Misc: 139 * nla_memcpy(dest, nla, count) copy attribute into memory 140 * nla_memcmp(nla, data, size) compare attribute with memory area 141 * nla_strlcpy(dst, nla, size) copy attribute to a sized string 142 * nla_strcmp(nla, str) compare attribute with string 143 * 144 * Attribute Parsing: 145 * nla_ok(nla, remaining) does nla fit into remaining bytes? 146 * nla_next(nla, remaining) get next netlink attribute 147 * nla_validate() validate a stream of attributes 148 * nla_validate_nested() validate a stream of nested attributes 149 * nla_find() find attribute in stream of attributes 150 * nla_find_nested() find attribute in nested attributes 151 * nla_parse() parse and validate stream of attrs 152 * nla_parse_nested() parse nested attribuets 153 * nla_for_each_attr() loop over all attributes 154 * nla_for_each_nested() loop over the nested attributes 155 *========================================================================= 156 */ 157 158 /** 159 * Standard attribute types to specify validation policy 160 */ 161 enum { 162 NLA_UNSPEC, 163 NLA_U8, 164 NLA_U16, 165 NLA_U32, 166 NLA_U64, 167 NLA_STRING, 168 NLA_FLAG, 169 NLA_MSECS, 170 NLA_NESTED, 171 NLA_NESTED_COMPAT, 172 NLA_NUL_STRING, 173 NLA_BINARY, 174 NLA_S8, 175 NLA_S16, 176 NLA_S32, 177 NLA_S64, 178 __NLA_TYPE_MAX, 179 }; 180 181 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) 182 183 /** 184 * struct nla_policy - attribute validation policy 185 * @type: Type of attribute or NLA_UNSPEC 186 * @len: Type specific length of payload 187 * 188 * Policies are defined as arrays of this struct, the array must be 189 * accessible by attribute type up to the highest identifier to be expected. 190 * 191 * Meaning of `len' field: 192 * NLA_STRING Maximum length of string 193 * NLA_NUL_STRING Maximum length of string (excluding NUL) 194 * NLA_FLAG Unused 195 * NLA_BINARY Maximum length of attribute payload 196 * NLA_NESTED Don't use `len' field -- length verification is 197 * done by checking len of nested header (or empty) 198 * NLA_NESTED_COMPAT Minimum length of structure payload 199 * NLA_U8, NLA_U16, 200 * NLA_U32, NLA_U64, 201 * NLA_S8, NLA_S16, 202 * NLA_S32, NLA_S64, 203 * NLA_MSECS Leaving the length field zero will verify the 204 * given type fits, using it verifies minimum length 205 * just like "All other" 206 * All other Minimum length of attribute payload 207 * 208 * Example: 209 * static const struct nla_policy my_policy[ATTR_MAX+1] = { 210 * [ATTR_FOO] = { .type = NLA_U16 }, 211 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, 212 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) }, 213 * }; 214 */ 215 struct nla_policy { 216 u16 type; 217 u16 len; 218 }; 219 220 /** 221 * struct nl_info - netlink source information 222 * @nlh: Netlink message header of original request 223 * @portid: Netlink PORTID of requesting application 224 */ 225 struct nl_info { 226 struct nlmsghdr *nlh; 227 struct net *nl_net; 228 u32 portid; 229 }; 230 231 int netlink_rcv_skb(struct sk_buff *skb, 232 int (*cb)(struct sk_buff *, struct nlmsghdr *)); 233 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, 234 unsigned int group, int report, gfp_t flags); 235 236 int nla_validate(const struct nlattr *head, int len, int maxtype, 237 const struct nla_policy *policy); 238 int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, 239 int len, const struct nla_policy *policy); 240 int nla_policy_len(const struct nla_policy *, int); 241 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype); 242 size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize); 243 int nla_memcpy(void *dest, const struct nlattr *src, int count); 244 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size); 245 int nla_strcmp(const struct nlattr *nla, const char *str); 246 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 247 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 248 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 249 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 250 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, 251 const void *data); 252 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 253 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); 254 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 255 int nla_append(struct sk_buff *skb, int attrlen, const void *data); 256 257 /************************************************************************** 258 * Netlink Messages 259 **************************************************************************/ 260 261 /** 262 * nlmsg_msg_size - length of netlink message not including padding 263 * @payload: length of message payload 264 */ 265 static inline int nlmsg_msg_size(int payload) 266 { 267 return NLMSG_HDRLEN + payload; 268 } 269 270 /** 271 * nlmsg_total_size - length of netlink message including padding 272 * @payload: length of message payload 273 */ 274 static inline int nlmsg_total_size(int payload) 275 { 276 return NLMSG_ALIGN(nlmsg_msg_size(payload)); 277 } 278 279 /** 280 * nlmsg_padlen - length of padding at the message's tail 281 * @payload: length of message payload 282 */ 283 static inline int nlmsg_padlen(int payload) 284 { 285 return nlmsg_total_size(payload) - nlmsg_msg_size(payload); 286 } 287 288 /** 289 * nlmsg_data - head of message payload 290 * @nlh: netlink message header 291 */ 292 static inline void *nlmsg_data(const struct nlmsghdr *nlh) 293 { 294 return (unsigned char *) nlh + NLMSG_HDRLEN; 295 } 296 297 /** 298 * nlmsg_len - length of message payload 299 * @nlh: netlink message header 300 */ 301 static inline int nlmsg_len(const struct nlmsghdr *nlh) 302 { 303 return nlh->nlmsg_len - NLMSG_HDRLEN; 304 } 305 306 /** 307 * nlmsg_attrdata - head of attributes data 308 * @nlh: netlink message header 309 * @hdrlen: length of family specific header 310 */ 311 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 312 int hdrlen) 313 { 314 unsigned char *data = nlmsg_data(nlh); 315 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); 316 } 317 318 /** 319 * nlmsg_attrlen - length of attributes data 320 * @nlh: netlink message header 321 * @hdrlen: length of family specific header 322 */ 323 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) 324 { 325 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); 326 } 327 328 /** 329 * nlmsg_ok - check if the netlink message fits into the remaining bytes 330 * @nlh: netlink message header 331 * @remaining: number of bytes remaining in message stream 332 */ 333 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) 334 { 335 return (remaining >= (int) sizeof(struct nlmsghdr) && 336 nlh->nlmsg_len >= sizeof(struct nlmsghdr) && 337 nlh->nlmsg_len <= remaining); 338 } 339 340 /** 341 * nlmsg_next - next netlink message in message stream 342 * @nlh: netlink message header 343 * @remaining: number of bytes remaining in message stream 344 * 345 * Returns the next netlink message in the message stream and 346 * decrements remaining by the size of the current message. 347 */ 348 static inline struct nlmsghdr * 349 nlmsg_next(const struct nlmsghdr *nlh, int *remaining) 350 { 351 int totlen = NLMSG_ALIGN(nlh->nlmsg_len); 352 353 *remaining -= totlen; 354 355 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); 356 } 357 358 /** 359 * nlmsg_parse - parse attributes of a netlink message 360 * @nlh: netlink message header 361 * @hdrlen: length of family specific header 362 * @tb: destination array with maxtype+1 elements 363 * @maxtype: maximum attribute type to be expected 364 * @policy: validation policy 365 * 366 * See nla_parse() 367 */ 368 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 369 struct nlattr *tb[], int maxtype, 370 const struct nla_policy *policy) 371 { 372 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 373 return -EINVAL; 374 375 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 376 nlmsg_attrlen(nlh, hdrlen), policy); 377 } 378 379 /** 380 * nlmsg_find_attr - find a specific attribute in a netlink message 381 * @nlh: netlink message header 382 * @hdrlen: length of familiy specific header 383 * @attrtype: type of attribute to look for 384 * 385 * Returns the first attribute which matches the specified type. 386 */ 387 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh, 388 int hdrlen, int attrtype) 389 { 390 return nla_find(nlmsg_attrdata(nlh, hdrlen), 391 nlmsg_attrlen(nlh, hdrlen), attrtype); 392 } 393 394 /** 395 * nlmsg_validate - validate a netlink message including attributes 396 * @nlh: netlinket message header 397 * @hdrlen: length of familiy specific header 398 * @maxtype: maximum attribute type to be expected 399 * @policy: validation policy 400 */ 401 static inline int nlmsg_validate(const struct nlmsghdr *nlh, 402 int hdrlen, int maxtype, 403 const struct nla_policy *policy) 404 { 405 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 406 return -EINVAL; 407 408 return nla_validate(nlmsg_attrdata(nlh, hdrlen), 409 nlmsg_attrlen(nlh, hdrlen), maxtype, policy); 410 } 411 412 /** 413 * nlmsg_report - need to report back to application? 414 * @nlh: netlink message header 415 * 416 * Returns 1 if a report back to the application is requested. 417 */ 418 static inline int nlmsg_report(const struct nlmsghdr *nlh) 419 { 420 return !!(nlh->nlmsg_flags & NLM_F_ECHO); 421 } 422 423 /** 424 * nlmsg_for_each_attr - iterate over a stream of attributes 425 * @pos: loop counter, set to current attribute 426 * @nlh: netlink message header 427 * @hdrlen: length of familiy specific header 428 * @rem: initialized to len, holds bytes currently remaining in stream 429 */ 430 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ 431 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ 432 nlmsg_attrlen(nlh, hdrlen), rem) 433 434 /** 435 * nlmsg_put - Add a new netlink message to an skb 436 * @skb: socket buffer to store message in 437 * @portid: netlink PORTID of requesting application 438 * @seq: sequence number of message 439 * @type: message type 440 * @payload: length of message payload 441 * @flags: message flags 442 * 443 * Returns NULL if the tailroom of the skb is insufficient to store 444 * the message header and payload. 445 */ 446 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, 447 int type, int payload, int flags) 448 { 449 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) 450 return NULL; 451 452 return __nlmsg_put(skb, portid, seq, type, payload, flags); 453 } 454 455 /** 456 * nlmsg_put_answer - Add a new callback based netlink message to an skb 457 * @skb: socket buffer to store message in 458 * @cb: netlink callback 459 * @type: message type 460 * @payload: length of message payload 461 * @flags: message flags 462 * 463 * Returns NULL if the tailroom of the skb is insufficient to store 464 * the message header and payload. 465 */ 466 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, 467 struct netlink_callback *cb, 468 int type, int payload, 469 int flags) 470 { 471 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 472 type, payload, flags); 473 } 474 475 /** 476 * nlmsg_new - Allocate a new netlink message 477 * @payload: size of the message payload 478 * @flags: the type of memory to allocate. 479 * 480 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known 481 * and a good default is needed. 482 */ 483 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) 484 { 485 return alloc_skb(nlmsg_total_size(payload), flags); 486 } 487 488 /** 489 * nlmsg_end - Finalize a netlink message 490 * @skb: socket buffer the message is stored in 491 * @nlh: netlink message header 492 * 493 * Corrects the netlink message header to include the appeneded 494 * attributes. Only necessary if attributes have been added to 495 * the message. 496 */ 497 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 498 { 499 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 500 } 501 502 /** 503 * nlmsg_get_pos - return current position in netlink message 504 * @skb: socket buffer the message is stored in 505 * 506 * Returns a pointer to the current tail of the message. 507 */ 508 static inline void *nlmsg_get_pos(struct sk_buff *skb) 509 { 510 return skb_tail_pointer(skb); 511 } 512 513 /** 514 * nlmsg_trim - Trim message to a mark 515 * @skb: socket buffer the message is stored in 516 * @mark: mark to trim to 517 * 518 * Trims the message to the provided mark. 519 */ 520 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 521 { 522 if (mark) { 523 WARN_ON((unsigned char *) mark < skb->data); 524 skb_trim(skb, (unsigned char *) mark - skb->data); 525 } 526 } 527 528 /** 529 * nlmsg_cancel - Cancel construction of a netlink message 530 * @skb: socket buffer the message is stored in 531 * @nlh: netlink message header 532 * 533 * Removes the complete netlink message including all 534 * attributes from the socket buffer again. 535 */ 536 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 537 { 538 nlmsg_trim(skb, nlh); 539 } 540 541 /** 542 * nlmsg_free - free a netlink message 543 * @skb: socket buffer of netlink message 544 */ 545 static inline void nlmsg_free(struct sk_buff *skb) 546 { 547 kfree_skb(skb); 548 } 549 550 /** 551 * nlmsg_multicast - multicast a netlink message 552 * @sk: netlink socket to spread messages to 553 * @skb: netlink message as socket buffer 554 * @portid: own netlink portid to avoid sending to yourself 555 * @group: multicast group id 556 * @flags: allocation flags 557 */ 558 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 559 u32 portid, unsigned int group, gfp_t flags) 560 { 561 int err; 562 563 NETLINK_CB(skb).dst_group = group; 564 565 err = netlink_broadcast(sk, skb, portid, group, flags); 566 if (err > 0) 567 err = 0; 568 569 return err; 570 } 571 572 /** 573 * nlmsg_unicast - unicast a netlink message 574 * @sk: netlink socket to spread message to 575 * @skb: netlink message as socket buffer 576 * @portid: netlink portid of the destination socket 577 */ 578 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid) 579 { 580 int err; 581 582 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT); 583 if (err > 0) 584 err = 0; 585 586 return err; 587 } 588 589 /** 590 * nlmsg_for_each_msg - iterate over a stream of messages 591 * @pos: loop counter, set to current message 592 * @head: head of message stream 593 * @len: length of message stream 594 * @rem: initialized to len, holds bytes currently remaining in stream 595 */ 596 #define nlmsg_for_each_msg(pos, head, len, rem) \ 597 for (pos = head, rem = len; \ 598 nlmsg_ok(pos, rem); \ 599 pos = nlmsg_next(pos, &(rem))) 600 601 /** 602 * nl_dump_check_consistent - check if sequence is consistent and advertise if not 603 * @cb: netlink callback structure that stores the sequence number 604 * @nlh: netlink message header to write the flag to 605 * 606 * This function checks if the sequence (generation) number changed during dump 607 * and if it did, advertises it in the netlink message header. 608 * 609 * The correct way to use it is to set cb->seq to the generation counter when 610 * all locks for dumping have been acquired, and then call this function for 611 * each message that is generated. 612 * 613 * Note that due to initialisation concerns, 0 is an invalid sequence number 614 * and must not be used by code that uses this functionality. 615 */ 616 static inline void 617 nl_dump_check_consistent(struct netlink_callback *cb, 618 struct nlmsghdr *nlh) 619 { 620 if (cb->prev_seq && cb->seq != cb->prev_seq) 621 nlh->nlmsg_flags |= NLM_F_DUMP_INTR; 622 cb->prev_seq = cb->seq; 623 } 624 625 /************************************************************************** 626 * Netlink Attributes 627 **************************************************************************/ 628 629 /** 630 * nla_attr_size - length of attribute not including padding 631 * @payload: length of payload 632 */ 633 static inline int nla_attr_size(int payload) 634 { 635 return NLA_HDRLEN + payload; 636 } 637 638 /** 639 * nla_total_size - total length of attribute including padding 640 * @payload: length of payload 641 */ 642 static inline int nla_total_size(int payload) 643 { 644 return NLA_ALIGN(nla_attr_size(payload)); 645 } 646 647 /** 648 * nla_padlen - length of padding at the tail of attribute 649 * @payload: length of payload 650 */ 651 static inline int nla_padlen(int payload) 652 { 653 return nla_total_size(payload) - nla_attr_size(payload); 654 } 655 656 /** 657 * nla_type - attribute type 658 * @nla: netlink attribute 659 */ 660 static inline int nla_type(const struct nlattr *nla) 661 { 662 return nla->nla_type & NLA_TYPE_MASK; 663 } 664 665 /** 666 * nla_data - head of payload 667 * @nla: netlink attribute 668 */ 669 static inline void *nla_data(const struct nlattr *nla) 670 { 671 return (char *) nla + NLA_HDRLEN; 672 } 673 674 /** 675 * nla_len - length of payload 676 * @nla: netlink attribute 677 */ 678 static inline int nla_len(const struct nlattr *nla) 679 { 680 return nla->nla_len - NLA_HDRLEN; 681 } 682 683 /** 684 * nla_ok - check if the netlink attribute fits into the remaining bytes 685 * @nla: netlink attribute 686 * @remaining: number of bytes remaining in attribute stream 687 */ 688 static inline int nla_ok(const struct nlattr *nla, int remaining) 689 { 690 return remaining >= (int) sizeof(*nla) && 691 nla->nla_len >= sizeof(*nla) && 692 nla->nla_len <= remaining; 693 } 694 695 /** 696 * nla_next - next netlink attribute in attribute stream 697 * @nla: netlink attribute 698 * @remaining: number of bytes remaining in attribute stream 699 * 700 * Returns the next netlink attribute in the attribute stream and 701 * decrements remaining by the size of the current attribute. 702 */ 703 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 704 { 705 int totlen = NLA_ALIGN(nla->nla_len); 706 707 *remaining -= totlen; 708 return (struct nlattr *) ((char *) nla + totlen); 709 } 710 711 /** 712 * nla_find_nested - find attribute in a set of nested attributes 713 * @nla: attribute containing the nested attributes 714 * @attrtype: type of attribute to look for 715 * 716 * Returns the first attribute which matches the specified type. 717 */ 718 static inline struct nlattr * 719 nla_find_nested(const struct nlattr *nla, int attrtype) 720 { 721 return nla_find(nla_data(nla), nla_len(nla), attrtype); 722 } 723 724 /** 725 * nla_parse_nested - parse nested attributes 726 * @tb: destination array with maxtype+1 elements 727 * @maxtype: maximum attribute type to be expected 728 * @nla: attribute containing the nested attributes 729 * @policy: validation policy 730 * 731 * See nla_parse() 732 */ 733 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 734 const struct nlattr *nla, 735 const struct nla_policy *policy) 736 { 737 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); 738 } 739 740 /** 741 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 742 * @skb: socket buffer to add attribute to 743 * @attrtype: attribute type 744 * @value: numeric value 745 */ 746 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 747 { 748 return nla_put(skb, attrtype, sizeof(u8), &value); 749 } 750 751 /** 752 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer 753 * @skb: socket buffer to add attribute to 754 * @attrtype: attribute type 755 * @value: numeric value 756 */ 757 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) 758 { 759 return nla_put(skb, attrtype, sizeof(u16), &value); 760 } 761 762 /** 763 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer 764 * @skb: socket buffer to add attribute to 765 * @attrtype: attribute type 766 * @value: numeric value 767 */ 768 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value) 769 { 770 return nla_put(skb, attrtype, sizeof(__be16), &value); 771 } 772 773 /** 774 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer 775 * @skb: socket buffer to add attribute to 776 * @attrtype: attribute type 777 * @value: numeric value 778 */ 779 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value) 780 { 781 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, value); 782 } 783 784 /** 785 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer 786 * @skb: socket buffer to add attribute to 787 * @attrtype: attribute type 788 * @value: numeric value 789 */ 790 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value) 791 { 792 return nla_put(skb, attrtype, sizeof(__le16), &value); 793 } 794 795 /** 796 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 797 * @skb: socket buffer to add attribute to 798 * @attrtype: attribute type 799 * @value: numeric value 800 */ 801 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 802 { 803 return nla_put(skb, attrtype, sizeof(u32), &value); 804 } 805 806 /** 807 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer 808 * @skb: socket buffer to add attribute to 809 * @attrtype: attribute type 810 * @value: numeric value 811 */ 812 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value) 813 { 814 return nla_put(skb, attrtype, sizeof(__be32), &value); 815 } 816 817 /** 818 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer 819 * @skb: socket buffer to add attribute to 820 * @attrtype: attribute type 821 * @value: numeric value 822 */ 823 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value) 824 { 825 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, value); 826 } 827 828 /** 829 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer 830 * @skb: socket buffer to add attribute to 831 * @attrtype: attribute type 832 * @value: numeric value 833 */ 834 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value) 835 { 836 return nla_put(skb, attrtype, sizeof(__le32), &value); 837 } 838 839 /** 840 * nla_put_u64 - Add a u64 netlink attribute to a socket buffer 841 * @skb: socket buffer to add attribute to 842 * @attrtype: attribute type 843 * @value: numeric value 844 */ 845 static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value) 846 { 847 return nla_put(skb, attrtype, sizeof(u64), &value); 848 } 849 850 /** 851 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer 852 * @skb: socket buffer to add attribute to 853 * @attrtype: attribute type 854 * @value: numeric value 855 */ 856 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value) 857 { 858 return nla_put(skb, attrtype, sizeof(__be64), &value); 859 } 860 861 /** 862 * nla_put_net64 - Add 64-bit network byte order netlink attribute to a socket buffer 863 * @skb: socket buffer to add attribute to 864 * @attrtype: attribute type 865 * @value: numeric value 866 */ 867 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value) 868 { 869 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, value); 870 } 871 872 /** 873 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer 874 * @skb: socket buffer to add attribute to 875 * @attrtype: attribute type 876 * @value: numeric value 877 */ 878 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value) 879 { 880 return nla_put(skb, attrtype, sizeof(__le64), &value); 881 } 882 883 /** 884 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer 885 * @skb: socket buffer to add attribute to 886 * @attrtype: attribute type 887 * @value: numeric value 888 */ 889 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value) 890 { 891 return nla_put(skb, attrtype, sizeof(s8), &value); 892 } 893 894 /** 895 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer 896 * @skb: socket buffer to add attribute to 897 * @attrtype: attribute type 898 * @value: numeric value 899 */ 900 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value) 901 { 902 return nla_put(skb, attrtype, sizeof(s16), &value); 903 } 904 905 /** 906 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer 907 * @skb: socket buffer to add attribute to 908 * @attrtype: attribute type 909 * @value: numeric value 910 */ 911 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value) 912 { 913 return nla_put(skb, attrtype, sizeof(s32), &value); 914 } 915 916 /** 917 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer 918 * @skb: socket buffer to add attribute to 919 * @attrtype: attribute type 920 * @value: numeric value 921 */ 922 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value) 923 { 924 return nla_put(skb, attrtype, sizeof(s64), &value); 925 } 926 927 /** 928 * nla_put_string - Add a string netlink attribute to a socket buffer 929 * @skb: socket buffer to add attribute to 930 * @attrtype: attribute type 931 * @str: NUL terminated string 932 */ 933 static inline int nla_put_string(struct sk_buff *skb, int attrtype, 934 const char *str) 935 { 936 return nla_put(skb, attrtype, strlen(str) + 1, str); 937 } 938 939 /** 940 * nla_put_flag - Add a flag netlink attribute to a socket buffer 941 * @skb: socket buffer to add attribute to 942 * @attrtype: attribute type 943 */ 944 static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 945 { 946 return nla_put(skb, attrtype, 0, NULL); 947 } 948 949 /** 950 * nla_put_msecs - Add a msecs netlink attribute to a socket buffer 951 * @skb: socket buffer to add attribute to 952 * @attrtype: attribute type 953 * @njiffies: number of jiffies to convert to msecs 954 */ 955 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 956 unsigned long njiffies) 957 { 958 u64 tmp = jiffies_to_msecs(njiffies); 959 return nla_put(skb, attrtype, sizeof(u64), &tmp); 960 } 961 962 /** 963 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket 964 * buffer 965 * @skb: socket buffer to add attribute to 966 * @attrtype: attribute type 967 * @addr: IPv4 address 968 */ 969 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype, 970 __be32 addr) 971 { 972 return nla_put_be32(skb, attrtype, addr); 973 } 974 975 /** 976 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket 977 * buffer 978 * @skb: socket buffer to add attribute to 979 * @attrtype: attribute type 980 * @addr: IPv6 address 981 */ 982 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype, 983 const struct in6_addr *addr) 984 { 985 return nla_put(skb, attrtype, sizeof(*addr), addr); 986 } 987 988 /** 989 * nla_get_u32 - return payload of u32 attribute 990 * @nla: u32 netlink attribute 991 */ 992 static inline u32 nla_get_u32(const struct nlattr *nla) 993 { 994 return *(u32 *) nla_data(nla); 995 } 996 997 /** 998 * nla_get_be32 - return payload of __be32 attribute 999 * @nla: __be32 netlink attribute 1000 */ 1001 static inline __be32 nla_get_be32(const struct nlattr *nla) 1002 { 1003 return *(__be32 *) nla_data(nla); 1004 } 1005 1006 /** 1007 * nla_get_u16 - return payload of u16 attribute 1008 * @nla: u16 netlink attribute 1009 */ 1010 static inline u16 nla_get_u16(const struct nlattr *nla) 1011 { 1012 return *(u16 *) nla_data(nla); 1013 } 1014 1015 /** 1016 * nla_get_be16 - return payload of __be16 attribute 1017 * @nla: __be16 netlink attribute 1018 */ 1019 static inline __be16 nla_get_be16(const struct nlattr *nla) 1020 { 1021 return *(__be16 *) nla_data(nla); 1022 } 1023 1024 /** 1025 * nla_get_le16 - return payload of __le16 attribute 1026 * @nla: __le16 netlink attribute 1027 */ 1028 static inline __le16 nla_get_le16(const struct nlattr *nla) 1029 { 1030 return *(__le16 *) nla_data(nla); 1031 } 1032 1033 /** 1034 * nla_get_u8 - return payload of u8 attribute 1035 * @nla: u8 netlink attribute 1036 */ 1037 static inline u8 nla_get_u8(const struct nlattr *nla) 1038 { 1039 return *(u8 *) nla_data(nla); 1040 } 1041 1042 /** 1043 * nla_get_u64 - return payload of u64 attribute 1044 * @nla: u64 netlink attribute 1045 */ 1046 static inline u64 nla_get_u64(const struct nlattr *nla) 1047 { 1048 u64 tmp; 1049 1050 nla_memcpy(&tmp, nla, sizeof(tmp)); 1051 1052 return tmp; 1053 } 1054 1055 /** 1056 * nla_get_be64 - return payload of __be64 attribute 1057 * @nla: __be64 netlink attribute 1058 */ 1059 static inline __be64 nla_get_be64(const struct nlattr *nla) 1060 { 1061 __be64 tmp; 1062 1063 nla_memcpy(&tmp, nla, sizeof(tmp)); 1064 1065 return tmp; 1066 } 1067 1068 /** 1069 * nla_get_s32 - return payload of s32 attribute 1070 * @nla: s32 netlink attribute 1071 */ 1072 static inline s32 nla_get_s32(const struct nlattr *nla) 1073 { 1074 return *(s32 *) nla_data(nla); 1075 } 1076 1077 /** 1078 * nla_get_s16 - return payload of s16 attribute 1079 * @nla: s16 netlink attribute 1080 */ 1081 static inline s16 nla_get_s16(const struct nlattr *nla) 1082 { 1083 return *(s16 *) nla_data(nla); 1084 } 1085 1086 /** 1087 * nla_get_s8 - return payload of s8 attribute 1088 * @nla: s8 netlink attribute 1089 */ 1090 static inline s8 nla_get_s8(const struct nlattr *nla) 1091 { 1092 return *(s8 *) nla_data(nla); 1093 } 1094 1095 /** 1096 * nla_get_s64 - return payload of s64 attribute 1097 * @nla: s64 netlink attribute 1098 */ 1099 static inline s64 nla_get_s64(const struct nlattr *nla) 1100 { 1101 s64 tmp; 1102 1103 nla_memcpy(&tmp, nla, sizeof(tmp)); 1104 1105 return tmp; 1106 } 1107 1108 /** 1109 * nla_get_flag - return payload of flag attribute 1110 * @nla: flag netlink attribute 1111 */ 1112 static inline int nla_get_flag(const struct nlattr *nla) 1113 { 1114 return !!nla; 1115 } 1116 1117 /** 1118 * nla_get_msecs - return payload of msecs attribute 1119 * @nla: msecs netlink attribute 1120 * 1121 * Returns the number of milliseconds in jiffies. 1122 */ 1123 static inline unsigned long nla_get_msecs(const struct nlattr *nla) 1124 { 1125 u64 msecs = nla_get_u64(nla); 1126 1127 return msecs_to_jiffies((unsigned long) msecs); 1128 } 1129 1130 /** 1131 * nla_get_in_addr - return payload of IPv4 address attribute 1132 * @nla: IPv4 address netlink attribute 1133 */ 1134 static inline __be32 nla_get_in_addr(const struct nlattr *nla) 1135 { 1136 return *(__be32 *) nla_data(nla); 1137 } 1138 1139 /** 1140 * nla_get_in6_addr - return payload of IPv6 address attribute 1141 * @nla: IPv6 address netlink attribute 1142 */ 1143 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla) 1144 { 1145 struct in6_addr tmp; 1146 1147 nla_memcpy(&tmp, nla, sizeof(tmp)); 1148 return tmp; 1149 } 1150 1151 /** 1152 * nla_nest_start - Start a new level of nested attributes 1153 * @skb: socket buffer to add attributes to 1154 * @attrtype: attribute type of container 1155 * 1156 * Returns the container attribute 1157 */ 1158 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 1159 { 1160 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 1161 1162 if (nla_put(skb, attrtype, 0, NULL) < 0) 1163 return NULL; 1164 1165 return start; 1166 } 1167 1168 /** 1169 * nla_nest_end - Finalize nesting of attributes 1170 * @skb: socket buffer the attributes are stored in 1171 * @start: container attribute 1172 * 1173 * Corrects the container attribute header to include the all 1174 * appeneded attributes. 1175 * 1176 * Returns the total data length of the skb. 1177 */ 1178 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 1179 { 1180 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1181 return skb->len; 1182 } 1183 1184 /** 1185 * nla_nest_cancel - Cancel nesting of attributes 1186 * @skb: socket buffer the message is stored in 1187 * @start: container attribute 1188 * 1189 * Removes the container attribute and including all nested 1190 * attributes. Returns -EMSGSIZE 1191 */ 1192 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 1193 { 1194 nlmsg_trim(skb, start); 1195 } 1196 1197 /** 1198 * nla_validate_nested - Validate a stream of nested attributes 1199 * @start: container attribute 1200 * @maxtype: maximum attribute type to be expected 1201 * @policy: validation policy 1202 * 1203 * Validates all attributes in the nested attribute stream against the 1204 * specified policy. Attributes with a type exceeding maxtype will be 1205 * ignored. See documenation of struct nla_policy for more details. 1206 * 1207 * Returns 0 on success or a negative error code. 1208 */ 1209 static inline int nla_validate_nested(const struct nlattr *start, int maxtype, 1210 const struct nla_policy *policy) 1211 { 1212 return nla_validate(nla_data(start), nla_len(start), maxtype, policy); 1213 } 1214 1215 /** 1216 * nla_for_each_attr - iterate over a stream of attributes 1217 * @pos: loop counter, set to current attribute 1218 * @head: head of attribute stream 1219 * @len: length of attribute stream 1220 * @rem: initialized to len, holds bytes currently remaining in stream 1221 */ 1222 #define nla_for_each_attr(pos, head, len, rem) \ 1223 for (pos = head, rem = len; \ 1224 nla_ok(pos, rem); \ 1225 pos = nla_next(pos, &(rem))) 1226 1227 /** 1228 * nla_for_each_nested - iterate over nested attributes 1229 * @pos: loop counter, set to current attribute 1230 * @nla: attribute containing the nested attributes 1231 * @rem: initialized to len, holds bytes currently remaining in stream 1232 */ 1233 #define nla_for_each_nested(pos, nla, rem) \ 1234 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 1235 1236 /** 1237 * nla_is_last - Test if attribute is last in stream 1238 * @nla: attribute to test 1239 * @rem: bytes remaining in stream 1240 */ 1241 static inline bool nla_is_last(const struct nlattr *nla, int rem) 1242 { 1243 return nla->nla_len == rem; 1244 } 1245 1246 #endif 1247