1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __NET_NETLINK_H 3 #define __NET_NETLINK_H 4 5 #include <linux/types.h> 6 #include <linux/netlink.h> 7 #include <linux/jiffies.h> 8 #include <linux/in6.h> 9 10 /* ======================================================================== 11 * Netlink Messages and Attributes Interface (As Seen On TV) 12 * ------------------------------------------------------------------------ 13 * Messages Interface 14 * ------------------------------------------------------------------------ 15 * 16 * Message Format: 17 * <--- nlmsg_total_size(payload) ---> 18 * <-- nlmsg_msg_size(payload) -> 19 * +----------+- - -+-------------+- - -+-------- - - 20 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr 21 * +----------+- - -+-------------+- - -+-------- - - 22 * nlmsg_data(nlh)---^ ^ 23 * nlmsg_next(nlh)-----------------------+ 24 * 25 * Payload Format: 26 * <---------------------- nlmsg_len(nlh) ---------------------> 27 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) -> 28 * +----------------------+- - -+--------------------------------+ 29 * | Family Header | Pad | Attributes | 30 * +----------------------+- - -+--------------------------------+ 31 * nlmsg_attrdata(nlh, hdrlen)---^ 32 * 33 * Data Structures: 34 * struct nlmsghdr netlink message header 35 * 36 * Message Construction: 37 * nlmsg_new() create a new netlink message 38 * nlmsg_put() add a netlink message to an skb 39 * nlmsg_put_answer() callback based nlmsg_put() 40 * nlmsg_end() finalize netlink message 41 * nlmsg_get_pos() return current position in message 42 * nlmsg_trim() trim part of message 43 * nlmsg_cancel() cancel message construction 44 * nlmsg_free() free a netlink message 45 * 46 * Message Sending: 47 * nlmsg_multicast() multicast message to several groups 48 * nlmsg_unicast() unicast a message to a single socket 49 * nlmsg_notify() send notification message 50 * 51 * Message Length Calculations: 52 * nlmsg_msg_size(payload) length of message w/o padding 53 * nlmsg_total_size(payload) length of message w/ padding 54 * nlmsg_padlen(payload) length of padding at tail 55 * 56 * Message Payload Access: 57 * nlmsg_data(nlh) head of message payload 58 * nlmsg_len(nlh) length of message payload 59 * nlmsg_attrdata(nlh, hdrlen) head of attributes data 60 * nlmsg_attrlen(nlh, hdrlen) length of attributes data 61 * 62 * Message Parsing: 63 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes? 64 * nlmsg_next(nlh, remaining) get next netlink message 65 * nlmsg_parse() parse attributes of a message 66 * nlmsg_find_attr() find an attribute in a message 67 * nlmsg_for_each_msg() loop over all messages 68 * nlmsg_validate() validate netlink message incl. attrs 69 * nlmsg_for_each_attr() loop over all attributes 70 * 71 * Misc: 72 * nlmsg_report() report back to application? 73 * 74 * ------------------------------------------------------------------------ 75 * Attributes Interface 76 * ------------------------------------------------------------------------ 77 * 78 * Attribute Format: 79 * <------- nla_total_size(payload) -------> 80 * <---- nla_attr_size(payload) -----> 81 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 82 * | Header | Pad | Payload | Pad | Header 83 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 84 * <- nla_len(nla) -> ^ 85 * nla_data(nla)----^ | 86 * nla_next(nla)-----------------------------' 87 * 88 * Data Structures: 89 * struct nlattr netlink attribute header 90 * 91 * Attribute Construction: 92 * nla_reserve(skb, type, len) reserve room for an attribute 93 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr 94 * nla_put(skb, type, len, data) add attribute to skb 95 * nla_put_nohdr(skb, len, data) add attribute w/o hdr 96 * nla_append(skb, len, data) append data to skb 97 * 98 * Attribute Construction for Basic Types: 99 * nla_put_u8(skb, type, value) add u8 attribute to skb 100 * nla_put_u16(skb, type, value) add u16 attribute to skb 101 * nla_put_u32(skb, type, value) add u32 attribute to skb 102 * nla_put_u64_64bit(skb, type, 103 * value, padattr) add u64 attribute to skb 104 * nla_put_s8(skb, type, value) add s8 attribute to skb 105 * nla_put_s16(skb, type, value) add s16 attribute to skb 106 * nla_put_s32(skb, type, value) add s32 attribute to skb 107 * nla_put_s64(skb, type, value, 108 * padattr) add s64 attribute to skb 109 * nla_put_string(skb, type, str) add string attribute to skb 110 * nla_put_flag(skb, type) add flag attribute to skb 111 * nla_put_msecs(skb, type, jiffies, 112 * padattr) add msecs attribute to skb 113 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb 114 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb 115 * 116 * Nested Attributes Construction: 117 * nla_nest_start(skb, type) start a nested attribute 118 * nla_nest_end(skb, nla) finalize a nested attribute 119 * nla_nest_cancel(skb, nla) cancel nested attribute construction 120 * 121 * Attribute Length Calculations: 122 * nla_attr_size(payload) length of attribute w/o padding 123 * nla_total_size(payload) length of attribute w/ padding 124 * nla_padlen(payload) length of padding 125 * 126 * Attribute Payload Access: 127 * nla_data(nla) head of attribute payload 128 * nla_len(nla) length of attribute payload 129 * 130 * Attribute Payload Access for Basic Types: 131 * nla_get_u8(nla) get payload for a u8 attribute 132 * nla_get_u16(nla) get payload for a u16 attribute 133 * nla_get_u32(nla) get payload for a u32 attribute 134 * nla_get_u64(nla) get payload for a u64 attribute 135 * nla_get_s8(nla) get payload for a s8 attribute 136 * nla_get_s16(nla) get payload for a s16 attribute 137 * nla_get_s32(nla) get payload for a s32 attribute 138 * nla_get_s64(nla) get payload for a s64 attribute 139 * nla_get_flag(nla) return 1 if flag is true 140 * nla_get_msecs(nla) get payload for a msecs attribute 141 * 142 * Attribute Misc: 143 * nla_memcpy(dest, nla, count) copy attribute into memory 144 * nla_memcmp(nla, data, size) compare attribute with memory area 145 * nla_strlcpy(dst, nla, size) copy attribute to a sized string 146 * nla_strcmp(nla, str) compare attribute with string 147 * 148 * Attribute Parsing: 149 * nla_ok(nla, remaining) does nla fit into remaining bytes? 150 * nla_next(nla, remaining) get next netlink attribute 151 * nla_validate() validate a stream of attributes 152 * nla_validate_nested() validate a stream of nested attributes 153 * nla_find() find attribute in stream of attributes 154 * nla_find_nested() find attribute in nested attributes 155 * nla_parse() parse and validate stream of attrs 156 * nla_parse_nested() parse nested attributes 157 * nla_for_each_attr() loop over all attributes 158 * nla_for_each_nested() loop over the nested attributes 159 *========================================================================= 160 */ 161 162 /** 163 * Standard attribute types to specify validation policy 164 */ 165 enum { 166 NLA_UNSPEC, 167 NLA_U8, 168 NLA_U16, 169 NLA_U32, 170 NLA_U64, 171 NLA_STRING, 172 NLA_FLAG, 173 NLA_MSECS, 174 NLA_NESTED, 175 NLA_NESTED_ARRAY, 176 NLA_NUL_STRING, 177 NLA_BINARY, 178 NLA_S8, 179 NLA_S16, 180 NLA_S32, 181 NLA_S64, 182 NLA_BITFIELD32, 183 NLA_REJECT, 184 NLA_EXACT_LEN, 185 NLA_EXACT_LEN_WARN, 186 __NLA_TYPE_MAX, 187 }; 188 189 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) 190 191 enum nla_policy_validation { 192 NLA_VALIDATE_NONE, 193 NLA_VALIDATE_RANGE, 194 NLA_VALIDATE_MIN, 195 NLA_VALIDATE_MAX, 196 NLA_VALIDATE_FUNCTION, 197 }; 198 199 /** 200 * struct nla_policy - attribute validation policy 201 * @type: Type of attribute or NLA_UNSPEC 202 * @validation_type: type of attribute validation done in addition to 203 * type-specific validation (e.g. range, function call), see 204 * &enum nla_policy_validation 205 * @len: Type specific length of payload 206 * 207 * Policies are defined as arrays of this struct, the array must be 208 * accessible by attribute type up to the highest identifier to be expected. 209 * 210 * Meaning of `len' field: 211 * NLA_STRING Maximum length of string 212 * NLA_NUL_STRING Maximum length of string (excluding NUL) 213 * NLA_FLAG Unused 214 * NLA_BINARY Maximum length of attribute payload 215 * NLA_NESTED, 216 * NLA_NESTED_ARRAY Length verification is done by checking len of 217 * nested header (or empty); len field is used if 218 * validation_data is also used, for the max attr 219 * number in the nested policy. 220 * NLA_U8, NLA_U16, 221 * NLA_U32, NLA_U64, 222 * NLA_S8, NLA_S16, 223 * NLA_S32, NLA_S64, 224 * NLA_MSECS Leaving the length field zero will verify the 225 * given type fits, using it verifies minimum length 226 * just like "All other" 227 * NLA_BITFIELD32 Unused 228 * NLA_REJECT Unused 229 * NLA_EXACT_LEN Attribute must have exactly this length, otherwise 230 * it is rejected. 231 * NLA_EXACT_LEN_WARN Attribute should have exactly this length, a warning 232 * is logged if it is longer, shorter is rejected. 233 * All other Minimum length of attribute payload 234 * 235 * Meaning of `validation_data' field: 236 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and 237 * validation data must point to a u32 value of valid 238 * flags 239 * NLA_REJECT This attribute is always rejected and validation data 240 * may point to a string to report as the error instead 241 * of the generic one in extended ACK. 242 * NLA_NESTED Points to a nested policy to validate, must also set 243 * `len' to the max attribute number. 244 * Note that nla_parse() will validate, but of course not 245 * parse, the nested sub-policies. 246 * NLA_NESTED_ARRAY Points to a nested policy to validate, must also set 247 * `len' to the max attribute number. The difference to 248 * NLA_NESTED is the structure - NLA_NESTED has the 249 * nested attributes directly inside, while an array has 250 * the nested attributes at another level down and the 251 * attributes directly in the nesting don't matter. 252 * All other Unused - but note that it's a union 253 * 254 * Meaning of `min' and `max' fields, use via NLA_POLICY_MIN, NLA_POLICY_MAX 255 * and NLA_POLICY_RANGE: 256 * NLA_U8, 257 * NLA_U16, 258 * NLA_U32, 259 * NLA_U64, 260 * NLA_S8, 261 * NLA_S16, 262 * NLA_S32, 263 * NLA_S64 These are used depending on the validation_type 264 * field, if that is min/max/range then the minimum, 265 * maximum and both are used (respectively) to check 266 * the value of the integer attribute. 267 * Note that in the interest of code simplicity and 268 * struct size both limits are s16, so you cannot 269 * enforce a range that doesn't fall within the range 270 * of s16 - do that as usual in the code instead. 271 * All other Unused - but note that it's a union 272 * 273 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN: 274 * NLA_BINARY Validation function called for the attribute, 275 * not compatible with use of the validation_data 276 * as in NLA_BITFIELD32, NLA_REJECT, NLA_NESTED and 277 * NLA_NESTED_ARRAY. 278 * All other Unused - but note that it's a union 279 * 280 * Example: 281 * static const struct nla_policy my_policy[ATTR_MAX+1] = { 282 * [ATTR_FOO] = { .type = NLA_U16 }, 283 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, 284 * [ATTR_BAZ] = { .len = sizeof(struct mystruct) }, 285 * [ATTR_GOO] = { .type = NLA_BITFIELD32, .validation_data = &myvalidflags }, 286 * }; 287 */ 288 struct nla_policy { 289 u8 type; 290 u8 validation_type; 291 u16 len; 292 union { 293 const void *validation_data; 294 struct { 295 s16 min, max; 296 }; 297 int (*validate)(const struct nlattr *attr, 298 struct netlink_ext_ack *extack); 299 }; 300 }; 301 302 #define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len } 303 #define NLA_POLICY_EXACT_LEN_WARN(_len) { .type = NLA_EXACT_LEN_WARN, \ 304 .len = _len } 305 306 #define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) 307 #define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) 308 309 #define NLA_POLICY_NESTED(maxattr, policy) \ 310 { .type = NLA_NESTED, .validation_data = policy, .len = maxattr } 311 #define NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ 312 { .type = NLA_NESTED_ARRAY, .validation_data = policy, .len = maxattr } 313 314 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition)) 315 #define NLA_ENSURE_INT_TYPE(tp) \ 316 (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 || \ 317 tp == NLA_S16 || tp == NLA_U16 || \ 318 tp == NLA_S32 || tp == NLA_U32 || \ 319 tp == NLA_S64 || tp == NLA_U64) + tp) 320 #define NLA_ENSURE_NO_VALIDATION_PTR(tp) \ 321 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \ 322 tp != NLA_REJECT && \ 323 tp != NLA_NESTED && \ 324 tp != NLA_NESTED_ARRAY) + tp) 325 326 #define NLA_POLICY_RANGE(tp, _min, _max) { \ 327 .type = NLA_ENSURE_INT_TYPE(tp), \ 328 .validation_type = NLA_VALIDATE_RANGE, \ 329 .min = _min, \ 330 .max = _max \ 331 } 332 333 #define NLA_POLICY_MIN(tp, _min) { \ 334 .type = NLA_ENSURE_INT_TYPE(tp), \ 335 .validation_type = NLA_VALIDATE_MIN, \ 336 .min = _min, \ 337 } 338 339 #define NLA_POLICY_MAX(tp, _max) { \ 340 .type = NLA_ENSURE_INT_TYPE(tp), \ 341 .validation_type = NLA_VALIDATE_MAX, \ 342 .max = _max, \ 343 } 344 345 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \ 346 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \ 347 .validation_type = NLA_VALIDATE_FUNCTION, \ 348 .validate = fn, \ 349 .len = __VA_ARGS__ + 0, \ 350 } 351 352 /** 353 * struct nl_info - netlink source information 354 * @nlh: Netlink message header of original request 355 * @portid: Netlink PORTID of requesting application 356 */ 357 struct nl_info { 358 struct nlmsghdr *nlh; 359 struct net *nl_net; 360 u32 portid; 361 bool skip_notify; 362 }; 363 364 int netlink_rcv_skb(struct sk_buff *skb, 365 int (*cb)(struct sk_buff *, struct nlmsghdr *, 366 struct netlink_ext_ack *)); 367 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, 368 unsigned int group, int report, gfp_t flags); 369 370 int nla_validate(const struct nlattr *head, int len, int maxtype, 371 const struct nla_policy *policy, 372 struct netlink_ext_ack *extack); 373 int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, 374 int len, const struct nla_policy *policy, 375 struct netlink_ext_ack *extack); 376 int nla_parse_strict(struct nlattr **tb, int maxtype, const struct nlattr *head, 377 int len, const struct nla_policy *policy, 378 struct netlink_ext_ack *extack); 379 int nla_policy_len(const struct nla_policy *, int); 380 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype); 381 size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize); 382 char *nla_strdup(const struct nlattr *nla, gfp_t flags); 383 int nla_memcpy(void *dest, const struct nlattr *src, int count); 384 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size); 385 int nla_strcmp(const struct nlattr *nla, const char *str); 386 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 387 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, 388 int attrlen, int padattr); 389 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 390 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 391 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, 392 int attrlen, int padattr); 393 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 394 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, 395 const void *data); 396 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 397 const void *data, int padattr); 398 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 399 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); 400 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 401 const void *data, int padattr); 402 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 403 int nla_append(struct sk_buff *skb, int attrlen, const void *data); 404 405 /************************************************************************** 406 * Netlink Messages 407 **************************************************************************/ 408 409 /** 410 * nlmsg_msg_size - length of netlink message not including padding 411 * @payload: length of message payload 412 */ 413 static inline int nlmsg_msg_size(int payload) 414 { 415 return NLMSG_HDRLEN + payload; 416 } 417 418 /** 419 * nlmsg_total_size - length of netlink message including padding 420 * @payload: length of message payload 421 */ 422 static inline int nlmsg_total_size(int payload) 423 { 424 return NLMSG_ALIGN(nlmsg_msg_size(payload)); 425 } 426 427 /** 428 * nlmsg_padlen - length of padding at the message's tail 429 * @payload: length of message payload 430 */ 431 static inline int nlmsg_padlen(int payload) 432 { 433 return nlmsg_total_size(payload) - nlmsg_msg_size(payload); 434 } 435 436 /** 437 * nlmsg_data - head of message payload 438 * @nlh: netlink message header 439 */ 440 static inline void *nlmsg_data(const struct nlmsghdr *nlh) 441 { 442 return (unsigned char *) nlh + NLMSG_HDRLEN; 443 } 444 445 /** 446 * nlmsg_len - length of message payload 447 * @nlh: netlink message header 448 */ 449 static inline int nlmsg_len(const struct nlmsghdr *nlh) 450 { 451 return nlh->nlmsg_len - NLMSG_HDRLEN; 452 } 453 454 /** 455 * nlmsg_attrdata - head of attributes data 456 * @nlh: netlink message header 457 * @hdrlen: length of family specific header 458 */ 459 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 460 int hdrlen) 461 { 462 unsigned char *data = nlmsg_data(nlh); 463 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); 464 } 465 466 /** 467 * nlmsg_attrlen - length of attributes data 468 * @nlh: netlink message header 469 * @hdrlen: length of family specific header 470 */ 471 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) 472 { 473 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); 474 } 475 476 /** 477 * nlmsg_ok - check if the netlink message fits into the remaining bytes 478 * @nlh: netlink message header 479 * @remaining: number of bytes remaining in message stream 480 */ 481 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) 482 { 483 return (remaining >= (int) sizeof(struct nlmsghdr) && 484 nlh->nlmsg_len >= sizeof(struct nlmsghdr) && 485 nlh->nlmsg_len <= remaining); 486 } 487 488 /** 489 * nlmsg_next - next netlink message in message stream 490 * @nlh: netlink message header 491 * @remaining: number of bytes remaining in message stream 492 * 493 * Returns the next netlink message in the message stream and 494 * decrements remaining by the size of the current message. 495 */ 496 static inline struct nlmsghdr * 497 nlmsg_next(const struct nlmsghdr *nlh, int *remaining) 498 { 499 int totlen = NLMSG_ALIGN(nlh->nlmsg_len); 500 501 *remaining -= totlen; 502 503 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); 504 } 505 506 /** 507 * nlmsg_parse - parse attributes of a netlink message 508 * @nlh: netlink message header 509 * @hdrlen: length of family specific header 510 * @tb: destination array with maxtype+1 elements 511 * @maxtype: maximum attribute type to be expected 512 * @policy: validation policy 513 * @extack: extended ACK report struct 514 * 515 * See nla_parse() 516 */ 517 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 518 struct nlattr *tb[], int maxtype, 519 const struct nla_policy *policy, 520 struct netlink_ext_ack *extack) 521 { 522 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) { 523 NL_SET_ERR_MSG(extack, "Invalid header length"); 524 return -EINVAL; 525 } 526 527 return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 528 nlmsg_attrlen(nlh, hdrlen), policy, extack); 529 } 530 531 static inline int nlmsg_parse_strict(const struct nlmsghdr *nlh, int hdrlen, 532 struct nlattr *tb[], int maxtype, 533 const struct nla_policy *policy, 534 struct netlink_ext_ack *extack) 535 { 536 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) { 537 NL_SET_ERR_MSG(extack, "Invalid header length"); 538 return -EINVAL; 539 } 540 541 return nla_parse_strict(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 542 nlmsg_attrlen(nlh, hdrlen), policy, extack); 543 } 544 545 /** 546 * nlmsg_find_attr - find a specific attribute in a netlink message 547 * @nlh: netlink message header 548 * @hdrlen: length of familiy specific header 549 * @attrtype: type of attribute to look for 550 * 551 * Returns the first attribute which matches the specified type. 552 */ 553 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh, 554 int hdrlen, int attrtype) 555 { 556 return nla_find(nlmsg_attrdata(nlh, hdrlen), 557 nlmsg_attrlen(nlh, hdrlen), attrtype); 558 } 559 560 /** 561 * nlmsg_validate - validate a netlink message including attributes 562 * @nlh: netlinket message header 563 * @hdrlen: length of familiy specific header 564 * @maxtype: maximum attribute type to be expected 565 * @policy: validation policy 566 * @extack: extended ACK report struct 567 */ 568 static inline int nlmsg_validate(const struct nlmsghdr *nlh, 569 int hdrlen, int maxtype, 570 const struct nla_policy *policy, 571 struct netlink_ext_ack *extack) 572 { 573 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 574 return -EINVAL; 575 576 return nla_validate(nlmsg_attrdata(nlh, hdrlen), 577 nlmsg_attrlen(nlh, hdrlen), maxtype, policy, 578 extack); 579 } 580 581 /** 582 * nlmsg_report - need to report back to application? 583 * @nlh: netlink message header 584 * 585 * Returns 1 if a report back to the application is requested. 586 */ 587 static inline int nlmsg_report(const struct nlmsghdr *nlh) 588 { 589 return !!(nlh->nlmsg_flags & NLM_F_ECHO); 590 } 591 592 /** 593 * nlmsg_for_each_attr - iterate over a stream of attributes 594 * @pos: loop counter, set to current attribute 595 * @nlh: netlink message header 596 * @hdrlen: length of familiy specific header 597 * @rem: initialized to len, holds bytes currently remaining in stream 598 */ 599 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ 600 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ 601 nlmsg_attrlen(nlh, hdrlen), rem) 602 603 /** 604 * nlmsg_put - Add a new netlink message to an skb 605 * @skb: socket buffer to store message in 606 * @portid: netlink PORTID of requesting application 607 * @seq: sequence number of message 608 * @type: message type 609 * @payload: length of message payload 610 * @flags: message flags 611 * 612 * Returns NULL if the tailroom of the skb is insufficient to store 613 * the message header and payload. 614 */ 615 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, 616 int type, int payload, int flags) 617 { 618 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) 619 return NULL; 620 621 return __nlmsg_put(skb, portid, seq, type, payload, flags); 622 } 623 624 /** 625 * nlmsg_put_answer - Add a new callback based netlink message to an skb 626 * @skb: socket buffer to store message in 627 * @cb: netlink callback 628 * @type: message type 629 * @payload: length of message payload 630 * @flags: message flags 631 * 632 * Returns NULL if the tailroom of the skb is insufficient to store 633 * the message header and payload. 634 */ 635 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, 636 struct netlink_callback *cb, 637 int type, int payload, 638 int flags) 639 { 640 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 641 type, payload, flags); 642 } 643 644 /** 645 * nlmsg_new - Allocate a new netlink message 646 * @payload: size of the message payload 647 * @flags: the type of memory to allocate. 648 * 649 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known 650 * and a good default is needed. 651 */ 652 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) 653 { 654 return alloc_skb(nlmsg_total_size(payload), flags); 655 } 656 657 /** 658 * nlmsg_end - Finalize a netlink message 659 * @skb: socket buffer the message is stored in 660 * @nlh: netlink message header 661 * 662 * Corrects the netlink message header to include the appeneded 663 * attributes. Only necessary if attributes have been added to 664 * the message. 665 */ 666 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 667 { 668 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 669 } 670 671 /** 672 * nlmsg_get_pos - return current position in netlink message 673 * @skb: socket buffer the message is stored in 674 * 675 * Returns a pointer to the current tail of the message. 676 */ 677 static inline void *nlmsg_get_pos(struct sk_buff *skb) 678 { 679 return skb_tail_pointer(skb); 680 } 681 682 /** 683 * nlmsg_trim - Trim message to a mark 684 * @skb: socket buffer the message is stored in 685 * @mark: mark to trim to 686 * 687 * Trims the message to the provided mark. 688 */ 689 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 690 { 691 if (mark) { 692 WARN_ON((unsigned char *) mark < skb->data); 693 skb_trim(skb, (unsigned char *) mark - skb->data); 694 } 695 } 696 697 /** 698 * nlmsg_cancel - Cancel construction of a netlink message 699 * @skb: socket buffer the message is stored in 700 * @nlh: netlink message header 701 * 702 * Removes the complete netlink message including all 703 * attributes from the socket buffer again. 704 */ 705 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 706 { 707 nlmsg_trim(skb, nlh); 708 } 709 710 /** 711 * nlmsg_free - free a netlink message 712 * @skb: socket buffer of netlink message 713 */ 714 static inline void nlmsg_free(struct sk_buff *skb) 715 { 716 kfree_skb(skb); 717 } 718 719 /** 720 * nlmsg_multicast - multicast a netlink message 721 * @sk: netlink socket to spread messages to 722 * @skb: netlink message as socket buffer 723 * @portid: own netlink portid to avoid sending to yourself 724 * @group: multicast group id 725 * @flags: allocation flags 726 */ 727 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 728 u32 portid, unsigned int group, gfp_t flags) 729 { 730 int err; 731 732 NETLINK_CB(skb).dst_group = group; 733 734 err = netlink_broadcast(sk, skb, portid, group, flags); 735 if (err > 0) 736 err = 0; 737 738 return err; 739 } 740 741 /** 742 * nlmsg_unicast - unicast a netlink message 743 * @sk: netlink socket to spread message to 744 * @skb: netlink message as socket buffer 745 * @portid: netlink portid of the destination socket 746 */ 747 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid) 748 { 749 int err; 750 751 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT); 752 if (err > 0) 753 err = 0; 754 755 return err; 756 } 757 758 /** 759 * nlmsg_for_each_msg - iterate over a stream of messages 760 * @pos: loop counter, set to current message 761 * @head: head of message stream 762 * @len: length of message stream 763 * @rem: initialized to len, holds bytes currently remaining in stream 764 */ 765 #define nlmsg_for_each_msg(pos, head, len, rem) \ 766 for (pos = head, rem = len; \ 767 nlmsg_ok(pos, rem); \ 768 pos = nlmsg_next(pos, &(rem))) 769 770 /** 771 * nl_dump_check_consistent - check if sequence is consistent and advertise if not 772 * @cb: netlink callback structure that stores the sequence number 773 * @nlh: netlink message header to write the flag to 774 * 775 * This function checks if the sequence (generation) number changed during dump 776 * and if it did, advertises it in the netlink message header. 777 * 778 * The correct way to use it is to set cb->seq to the generation counter when 779 * all locks for dumping have been acquired, and then call this function for 780 * each message that is generated. 781 * 782 * Note that due to initialisation concerns, 0 is an invalid sequence number 783 * and must not be used by code that uses this functionality. 784 */ 785 static inline void 786 nl_dump_check_consistent(struct netlink_callback *cb, 787 struct nlmsghdr *nlh) 788 { 789 if (cb->prev_seq && cb->seq != cb->prev_seq) 790 nlh->nlmsg_flags |= NLM_F_DUMP_INTR; 791 cb->prev_seq = cb->seq; 792 } 793 794 /************************************************************************** 795 * Netlink Attributes 796 **************************************************************************/ 797 798 /** 799 * nla_attr_size - length of attribute not including padding 800 * @payload: length of payload 801 */ 802 static inline int nla_attr_size(int payload) 803 { 804 return NLA_HDRLEN + payload; 805 } 806 807 /** 808 * nla_total_size - total length of attribute including padding 809 * @payload: length of payload 810 */ 811 static inline int nla_total_size(int payload) 812 { 813 return NLA_ALIGN(nla_attr_size(payload)); 814 } 815 816 /** 817 * nla_padlen - length of padding at the tail of attribute 818 * @payload: length of payload 819 */ 820 static inline int nla_padlen(int payload) 821 { 822 return nla_total_size(payload) - nla_attr_size(payload); 823 } 824 825 /** 826 * nla_type - attribute type 827 * @nla: netlink attribute 828 */ 829 static inline int nla_type(const struct nlattr *nla) 830 { 831 return nla->nla_type & NLA_TYPE_MASK; 832 } 833 834 /** 835 * nla_data - head of payload 836 * @nla: netlink attribute 837 */ 838 static inline void *nla_data(const struct nlattr *nla) 839 { 840 return (char *) nla + NLA_HDRLEN; 841 } 842 843 /** 844 * nla_len - length of payload 845 * @nla: netlink attribute 846 */ 847 static inline int nla_len(const struct nlattr *nla) 848 { 849 return nla->nla_len - NLA_HDRLEN; 850 } 851 852 /** 853 * nla_ok - check if the netlink attribute fits into the remaining bytes 854 * @nla: netlink attribute 855 * @remaining: number of bytes remaining in attribute stream 856 */ 857 static inline int nla_ok(const struct nlattr *nla, int remaining) 858 { 859 return remaining >= (int) sizeof(*nla) && 860 nla->nla_len >= sizeof(*nla) && 861 nla->nla_len <= remaining; 862 } 863 864 /** 865 * nla_next - next netlink attribute in attribute stream 866 * @nla: netlink attribute 867 * @remaining: number of bytes remaining in attribute stream 868 * 869 * Returns the next netlink attribute in the attribute stream and 870 * decrements remaining by the size of the current attribute. 871 */ 872 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 873 { 874 unsigned int totlen = NLA_ALIGN(nla->nla_len); 875 876 *remaining -= totlen; 877 return (struct nlattr *) ((char *) nla + totlen); 878 } 879 880 /** 881 * nla_find_nested - find attribute in a set of nested attributes 882 * @nla: attribute containing the nested attributes 883 * @attrtype: type of attribute to look for 884 * 885 * Returns the first attribute which matches the specified type. 886 */ 887 static inline struct nlattr * 888 nla_find_nested(const struct nlattr *nla, int attrtype) 889 { 890 return nla_find(nla_data(nla), nla_len(nla), attrtype); 891 } 892 893 /** 894 * nla_parse_nested - parse nested attributes 895 * @tb: destination array with maxtype+1 elements 896 * @maxtype: maximum attribute type to be expected 897 * @nla: attribute containing the nested attributes 898 * @policy: validation policy 899 * @extack: extended ACK report struct 900 * 901 * See nla_parse() 902 */ 903 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 904 const struct nlattr *nla, 905 const struct nla_policy *policy, 906 struct netlink_ext_ack *extack) 907 { 908 return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, 909 extack); 910 } 911 912 /** 913 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 914 * @skb: socket buffer to add attribute to 915 * @attrtype: attribute type 916 * @value: numeric value 917 */ 918 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 919 { 920 /* temporary variables to work around GCC PR81715 with asan-stack=1 */ 921 u8 tmp = value; 922 923 return nla_put(skb, attrtype, sizeof(u8), &tmp); 924 } 925 926 /** 927 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer 928 * @skb: socket buffer to add attribute to 929 * @attrtype: attribute type 930 * @value: numeric value 931 */ 932 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) 933 { 934 u16 tmp = value; 935 936 return nla_put(skb, attrtype, sizeof(u16), &tmp); 937 } 938 939 /** 940 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer 941 * @skb: socket buffer to add attribute to 942 * @attrtype: attribute type 943 * @value: numeric value 944 */ 945 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value) 946 { 947 __be16 tmp = value; 948 949 return nla_put(skb, attrtype, sizeof(__be16), &tmp); 950 } 951 952 /** 953 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer 954 * @skb: socket buffer to add attribute to 955 * @attrtype: attribute type 956 * @value: numeric value 957 */ 958 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value) 959 { 960 __be16 tmp = value; 961 962 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 963 } 964 965 /** 966 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer 967 * @skb: socket buffer to add attribute to 968 * @attrtype: attribute type 969 * @value: numeric value 970 */ 971 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value) 972 { 973 __le16 tmp = value; 974 975 return nla_put(skb, attrtype, sizeof(__le16), &tmp); 976 } 977 978 /** 979 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 980 * @skb: socket buffer to add attribute to 981 * @attrtype: attribute type 982 * @value: numeric value 983 */ 984 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 985 { 986 u32 tmp = value; 987 988 return nla_put(skb, attrtype, sizeof(u32), &tmp); 989 } 990 991 /** 992 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer 993 * @skb: socket buffer to add attribute to 994 * @attrtype: attribute type 995 * @value: numeric value 996 */ 997 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value) 998 { 999 __be32 tmp = value; 1000 1001 return nla_put(skb, attrtype, sizeof(__be32), &tmp); 1002 } 1003 1004 /** 1005 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer 1006 * @skb: socket buffer to add attribute to 1007 * @attrtype: attribute type 1008 * @value: numeric value 1009 */ 1010 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value) 1011 { 1012 __be32 tmp = value; 1013 1014 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 1015 } 1016 1017 /** 1018 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer 1019 * @skb: socket buffer to add attribute to 1020 * @attrtype: attribute type 1021 * @value: numeric value 1022 */ 1023 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value) 1024 { 1025 __le32 tmp = value; 1026 1027 return nla_put(skb, attrtype, sizeof(__le32), &tmp); 1028 } 1029 1030 /** 1031 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it 1032 * @skb: socket buffer to add attribute to 1033 * @attrtype: attribute type 1034 * @value: numeric value 1035 * @padattr: attribute type for the padding 1036 */ 1037 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype, 1038 u64 value, int padattr) 1039 { 1040 u64 tmp = value; 1041 1042 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1043 } 1044 1045 /** 1046 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it 1047 * @skb: socket buffer to add attribute to 1048 * @attrtype: attribute type 1049 * @value: numeric value 1050 * @padattr: attribute type for the padding 1051 */ 1052 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value, 1053 int padattr) 1054 { 1055 __be64 tmp = value; 1056 1057 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr); 1058 } 1059 1060 /** 1061 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it 1062 * @skb: socket buffer to add attribute to 1063 * @attrtype: attribute type 1064 * @value: numeric value 1065 * @padattr: attribute type for the padding 1066 */ 1067 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value, 1068 int padattr) 1069 { 1070 __be64 tmp = value; 1071 1072 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp, 1073 padattr); 1074 } 1075 1076 /** 1077 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it 1078 * @skb: socket buffer to add attribute to 1079 * @attrtype: attribute type 1080 * @value: numeric value 1081 * @padattr: attribute type for the padding 1082 */ 1083 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value, 1084 int padattr) 1085 { 1086 __le64 tmp = value; 1087 1088 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr); 1089 } 1090 1091 /** 1092 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer 1093 * @skb: socket buffer to add attribute to 1094 * @attrtype: attribute type 1095 * @value: numeric value 1096 */ 1097 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value) 1098 { 1099 s8 tmp = value; 1100 1101 return nla_put(skb, attrtype, sizeof(s8), &tmp); 1102 } 1103 1104 /** 1105 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer 1106 * @skb: socket buffer to add attribute to 1107 * @attrtype: attribute type 1108 * @value: numeric value 1109 */ 1110 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value) 1111 { 1112 s16 tmp = value; 1113 1114 return nla_put(skb, attrtype, sizeof(s16), &tmp); 1115 } 1116 1117 /** 1118 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer 1119 * @skb: socket buffer to add attribute to 1120 * @attrtype: attribute type 1121 * @value: numeric value 1122 */ 1123 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value) 1124 { 1125 s32 tmp = value; 1126 1127 return nla_put(skb, attrtype, sizeof(s32), &tmp); 1128 } 1129 1130 /** 1131 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it 1132 * @skb: socket buffer to add attribute to 1133 * @attrtype: attribute type 1134 * @value: numeric value 1135 * @padattr: attribute type for the padding 1136 */ 1137 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value, 1138 int padattr) 1139 { 1140 s64 tmp = value; 1141 1142 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr); 1143 } 1144 1145 /** 1146 * nla_put_string - Add a string netlink attribute to a socket buffer 1147 * @skb: socket buffer to add attribute to 1148 * @attrtype: attribute type 1149 * @str: NUL terminated string 1150 */ 1151 static inline int nla_put_string(struct sk_buff *skb, int attrtype, 1152 const char *str) 1153 { 1154 return nla_put(skb, attrtype, strlen(str) + 1, str); 1155 } 1156 1157 /** 1158 * nla_put_flag - Add a flag netlink attribute to a socket buffer 1159 * @skb: socket buffer to add attribute to 1160 * @attrtype: attribute type 1161 */ 1162 static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 1163 { 1164 return nla_put(skb, attrtype, 0, NULL); 1165 } 1166 1167 /** 1168 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it 1169 * @skb: socket buffer to add attribute to 1170 * @attrtype: attribute type 1171 * @njiffies: number of jiffies to convert to msecs 1172 * @padattr: attribute type for the padding 1173 */ 1174 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 1175 unsigned long njiffies, int padattr) 1176 { 1177 u64 tmp = jiffies_to_msecs(njiffies); 1178 1179 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1180 } 1181 1182 /** 1183 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket 1184 * buffer 1185 * @skb: socket buffer to add attribute to 1186 * @attrtype: attribute type 1187 * @addr: IPv4 address 1188 */ 1189 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype, 1190 __be32 addr) 1191 { 1192 __be32 tmp = addr; 1193 1194 return nla_put_be32(skb, attrtype, tmp); 1195 } 1196 1197 /** 1198 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket 1199 * buffer 1200 * @skb: socket buffer to add attribute to 1201 * @attrtype: attribute type 1202 * @addr: IPv6 address 1203 */ 1204 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype, 1205 const struct in6_addr *addr) 1206 { 1207 return nla_put(skb, attrtype, sizeof(*addr), addr); 1208 } 1209 1210 /** 1211 * nla_get_u32 - return payload of u32 attribute 1212 * @nla: u32 netlink attribute 1213 */ 1214 static inline u32 nla_get_u32(const struct nlattr *nla) 1215 { 1216 return *(u32 *) nla_data(nla); 1217 } 1218 1219 /** 1220 * nla_get_be32 - return payload of __be32 attribute 1221 * @nla: __be32 netlink attribute 1222 */ 1223 static inline __be32 nla_get_be32(const struct nlattr *nla) 1224 { 1225 return *(__be32 *) nla_data(nla); 1226 } 1227 1228 /** 1229 * nla_get_le32 - return payload of __le32 attribute 1230 * @nla: __le32 netlink attribute 1231 */ 1232 static inline __le32 nla_get_le32(const struct nlattr *nla) 1233 { 1234 return *(__le32 *) nla_data(nla); 1235 } 1236 1237 /** 1238 * nla_get_u16 - return payload of u16 attribute 1239 * @nla: u16 netlink attribute 1240 */ 1241 static inline u16 nla_get_u16(const struct nlattr *nla) 1242 { 1243 return *(u16 *) nla_data(nla); 1244 } 1245 1246 /** 1247 * nla_get_be16 - return payload of __be16 attribute 1248 * @nla: __be16 netlink attribute 1249 */ 1250 static inline __be16 nla_get_be16(const struct nlattr *nla) 1251 { 1252 return *(__be16 *) nla_data(nla); 1253 } 1254 1255 /** 1256 * nla_get_le16 - return payload of __le16 attribute 1257 * @nla: __le16 netlink attribute 1258 */ 1259 static inline __le16 nla_get_le16(const struct nlattr *nla) 1260 { 1261 return *(__le16 *) nla_data(nla); 1262 } 1263 1264 /** 1265 * nla_get_u8 - return payload of u8 attribute 1266 * @nla: u8 netlink attribute 1267 */ 1268 static inline u8 nla_get_u8(const struct nlattr *nla) 1269 { 1270 return *(u8 *) nla_data(nla); 1271 } 1272 1273 /** 1274 * nla_get_u64 - return payload of u64 attribute 1275 * @nla: u64 netlink attribute 1276 */ 1277 static inline u64 nla_get_u64(const struct nlattr *nla) 1278 { 1279 u64 tmp; 1280 1281 nla_memcpy(&tmp, nla, sizeof(tmp)); 1282 1283 return tmp; 1284 } 1285 1286 /** 1287 * nla_get_be64 - return payload of __be64 attribute 1288 * @nla: __be64 netlink attribute 1289 */ 1290 static inline __be64 nla_get_be64(const struct nlattr *nla) 1291 { 1292 __be64 tmp; 1293 1294 nla_memcpy(&tmp, nla, sizeof(tmp)); 1295 1296 return tmp; 1297 } 1298 1299 /** 1300 * nla_get_le64 - return payload of __le64 attribute 1301 * @nla: __le64 netlink attribute 1302 */ 1303 static inline __le64 nla_get_le64(const struct nlattr *nla) 1304 { 1305 return *(__le64 *) nla_data(nla); 1306 } 1307 1308 /** 1309 * nla_get_s32 - return payload of s32 attribute 1310 * @nla: s32 netlink attribute 1311 */ 1312 static inline s32 nla_get_s32(const struct nlattr *nla) 1313 { 1314 return *(s32 *) nla_data(nla); 1315 } 1316 1317 /** 1318 * nla_get_s16 - return payload of s16 attribute 1319 * @nla: s16 netlink attribute 1320 */ 1321 static inline s16 nla_get_s16(const struct nlattr *nla) 1322 { 1323 return *(s16 *) nla_data(nla); 1324 } 1325 1326 /** 1327 * nla_get_s8 - return payload of s8 attribute 1328 * @nla: s8 netlink attribute 1329 */ 1330 static inline s8 nla_get_s8(const struct nlattr *nla) 1331 { 1332 return *(s8 *) nla_data(nla); 1333 } 1334 1335 /** 1336 * nla_get_s64 - return payload of s64 attribute 1337 * @nla: s64 netlink attribute 1338 */ 1339 static inline s64 nla_get_s64(const struct nlattr *nla) 1340 { 1341 s64 tmp; 1342 1343 nla_memcpy(&tmp, nla, sizeof(tmp)); 1344 1345 return tmp; 1346 } 1347 1348 /** 1349 * nla_get_flag - return payload of flag attribute 1350 * @nla: flag netlink attribute 1351 */ 1352 static inline int nla_get_flag(const struct nlattr *nla) 1353 { 1354 return !!nla; 1355 } 1356 1357 /** 1358 * nla_get_msecs - return payload of msecs attribute 1359 * @nla: msecs netlink attribute 1360 * 1361 * Returns the number of milliseconds in jiffies. 1362 */ 1363 static inline unsigned long nla_get_msecs(const struct nlattr *nla) 1364 { 1365 u64 msecs = nla_get_u64(nla); 1366 1367 return msecs_to_jiffies((unsigned long) msecs); 1368 } 1369 1370 /** 1371 * nla_get_in_addr - return payload of IPv4 address attribute 1372 * @nla: IPv4 address netlink attribute 1373 */ 1374 static inline __be32 nla_get_in_addr(const struct nlattr *nla) 1375 { 1376 return *(__be32 *) nla_data(nla); 1377 } 1378 1379 /** 1380 * nla_get_in6_addr - return payload of IPv6 address attribute 1381 * @nla: IPv6 address netlink attribute 1382 */ 1383 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla) 1384 { 1385 struct in6_addr tmp; 1386 1387 nla_memcpy(&tmp, nla, sizeof(tmp)); 1388 return tmp; 1389 } 1390 1391 /** 1392 * nla_get_bitfield32 - return payload of 32 bitfield attribute 1393 * @nla: nla_bitfield32 attribute 1394 */ 1395 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla) 1396 { 1397 struct nla_bitfield32 tmp; 1398 1399 nla_memcpy(&tmp, nla, sizeof(tmp)); 1400 return tmp; 1401 } 1402 1403 /** 1404 * nla_memdup - duplicate attribute memory (kmemdup) 1405 * @src: netlink attribute to duplicate from 1406 * @gfp: GFP mask 1407 */ 1408 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp) 1409 { 1410 return kmemdup(nla_data(src), nla_len(src), gfp); 1411 } 1412 1413 /** 1414 * nla_nest_start - Start a new level of nested attributes 1415 * @skb: socket buffer to add attributes to 1416 * @attrtype: attribute type of container 1417 * 1418 * Returns the container attribute 1419 */ 1420 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 1421 { 1422 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 1423 1424 if (nla_put(skb, attrtype, 0, NULL) < 0) 1425 return NULL; 1426 1427 return start; 1428 } 1429 1430 /** 1431 * nla_nest_end - Finalize nesting of attributes 1432 * @skb: socket buffer the attributes are stored in 1433 * @start: container attribute 1434 * 1435 * Corrects the container attribute header to include the all 1436 * appeneded attributes. 1437 * 1438 * Returns the total data length of the skb. 1439 */ 1440 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 1441 { 1442 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1443 return skb->len; 1444 } 1445 1446 /** 1447 * nla_nest_cancel - Cancel nesting of attributes 1448 * @skb: socket buffer the message is stored in 1449 * @start: container attribute 1450 * 1451 * Removes the container attribute and including all nested 1452 * attributes. Returns -EMSGSIZE 1453 */ 1454 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 1455 { 1456 nlmsg_trim(skb, start); 1457 } 1458 1459 /** 1460 * nla_validate_nested - Validate a stream of nested attributes 1461 * @start: container attribute 1462 * @maxtype: maximum attribute type to be expected 1463 * @policy: validation policy 1464 * @extack: extended ACK report struct 1465 * 1466 * Validates all attributes in the nested attribute stream against the 1467 * specified policy. Attributes with a type exceeding maxtype will be 1468 * ignored. See documenation of struct nla_policy for more details. 1469 * 1470 * Returns 0 on success or a negative error code. 1471 */ 1472 static inline int nla_validate_nested(const struct nlattr *start, int maxtype, 1473 const struct nla_policy *policy, 1474 struct netlink_ext_ack *extack) 1475 { 1476 return nla_validate(nla_data(start), nla_len(start), maxtype, policy, 1477 extack); 1478 } 1479 1480 /** 1481 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute 1482 * @skb: socket buffer the message is stored in 1483 * 1484 * Return true if padding is needed to align the next attribute (nla_data()) to 1485 * a 64-bit aligned area. 1486 */ 1487 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb) 1488 { 1489 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 1490 /* The nlattr header is 4 bytes in size, that's why we test 1491 * if the skb->data _is_ aligned. A NOP attribute, plus 1492 * nlattr header for next attribute, will make nla_data() 1493 * 8-byte aligned. 1494 */ 1495 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8)) 1496 return true; 1497 #endif 1498 return false; 1499 } 1500 1501 /** 1502 * nla_align_64bit - 64-bit align the nla_data() of next attribute 1503 * @skb: socket buffer the message is stored in 1504 * @padattr: attribute type for the padding 1505 * 1506 * Conditionally emit a padding netlink attribute in order to make 1507 * the next attribute we emit have a 64-bit aligned nla_data() area. 1508 * This will only be done in architectures which do not have 1509 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined. 1510 * 1511 * Returns zero on success or a negative error code. 1512 */ 1513 static inline int nla_align_64bit(struct sk_buff *skb, int padattr) 1514 { 1515 if (nla_need_padding_for_64bit(skb) && 1516 !nla_reserve(skb, padattr, 0)) 1517 return -EMSGSIZE; 1518 1519 return 0; 1520 } 1521 1522 /** 1523 * nla_total_size_64bit - total length of attribute including padding 1524 * @payload: length of payload 1525 */ 1526 static inline int nla_total_size_64bit(int payload) 1527 { 1528 return NLA_ALIGN(nla_attr_size(payload)) 1529 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 1530 + NLA_ALIGN(nla_attr_size(0)) 1531 #endif 1532 ; 1533 } 1534 1535 /** 1536 * nla_for_each_attr - iterate over a stream of attributes 1537 * @pos: loop counter, set to current attribute 1538 * @head: head of attribute stream 1539 * @len: length of attribute stream 1540 * @rem: initialized to len, holds bytes currently remaining in stream 1541 */ 1542 #define nla_for_each_attr(pos, head, len, rem) \ 1543 for (pos = head, rem = len; \ 1544 nla_ok(pos, rem); \ 1545 pos = nla_next(pos, &(rem))) 1546 1547 /** 1548 * nla_for_each_nested - iterate over nested attributes 1549 * @pos: loop counter, set to current attribute 1550 * @nla: attribute containing the nested attributes 1551 * @rem: initialized to len, holds bytes currently remaining in stream 1552 */ 1553 #define nla_for_each_nested(pos, nla, rem) \ 1554 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 1555 1556 /** 1557 * nla_is_last - Test if attribute is last in stream 1558 * @nla: attribute to test 1559 * @rem: bytes remaining in stream 1560 */ 1561 static inline bool nla_is_last(const struct nlattr *nla, int rem) 1562 { 1563 return nla->nla_len == rem; 1564 } 1565 1566 #endif 1567