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_consume() free a netlink message (expected) 45 * nlmsg_free() free a netlink message (drop) 46 * 47 * Message Sending: 48 * nlmsg_multicast() multicast message to several groups 49 * nlmsg_unicast() unicast a message to a single socket 50 * nlmsg_notify() send notification message 51 * 52 * Message Length Calculations: 53 * nlmsg_msg_size(payload) length of message w/o padding 54 * nlmsg_total_size(payload) length of message w/ padding 55 * nlmsg_padlen(payload) length of padding at tail 56 * 57 * Message Payload Access: 58 * nlmsg_data(nlh) head of message payload 59 * nlmsg_len(nlh) length of message payload 60 * nlmsg_attrdata(nlh, hdrlen) head of attributes data 61 * nlmsg_attrlen(nlh, hdrlen) length of attributes data 62 * 63 * Message Parsing: 64 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes? 65 * nlmsg_next(nlh, remaining) get next netlink message 66 * nlmsg_parse() parse attributes of a message 67 * nlmsg_find_attr() find an attribute in a message 68 * nlmsg_for_each_msg() loop over all messages 69 * nlmsg_validate() validate netlink message incl. attrs 70 * nlmsg_for_each_attr() loop over all attributes 71 * 72 * Misc: 73 * nlmsg_report() report back to application? 74 * 75 * ------------------------------------------------------------------------ 76 * Attributes Interface 77 * ------------------------------------------------------------------------ 78 * 79 * Attribute Format: 80 * <------- nla_total_size(payload) -------> 81 * <---- nla_attr_size(payload) -----> 82 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 83 * | Header | Pad | Payload | Pad | Header 84 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 85 * <- nla_len(nla) -> ^ 86 * nla_data(nla)----^ | 87 * nla_next(nla)-----------------------------' 88 * 89 * Data Structures: 90 * struct nlattr netlink attribute header 91 * 92 * Attribute Construction: 93 * nla_reserve(skb, type, len) reserve room for an attribute 94 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr 95 * nla_put(skb, type, len, data) add attribute to skb 96 * nla_put_nohdr(skb, len, data) add attribute w/o hdr 97 * nla_append(skb, len, data) append data to skb 98 * 99 * Attribute Construction for Basic Types: 100 * nla_put_u8(skb, type, value) add u8 attribute to skb 101 * nla_put_u16(skb, type, value) add u16 attribute to skb 102 * nla_put_u32(skb, type, value) add u32 attribute to skb 103 * nla_put_u64_64bit(skb, type, 104 * value, padattr) add u64 attribute to skb 105 * nla_put_s8(skb, type, value) add s8 attribute to skb 106 * nla_put_s16(skb, type, value) add s16 attribute to skb 107 * nla_put_s32(skb, type, value) add s32 attribute to skb 108 * nla_put_s64(skb, type, value, 109 * padattr) add s64 attribute to skb 110 * nla_put_string(skb, type, str) add string attribute to skb 111 * nla_put_flag(skb, type) add flag attribute to skb 112 * nla_put_msecs(skb, type, jiffies, 113 * padattr) add msecs attribute to skb 114 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb 115 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb 116 * 117 * Nested Attributes Construction: 118 * nla_nest_start(skb, type) start a nested attribute 119 * nla_nest_end(skb, nla) finalize a nested attribute 120 * nla_nest_cancel(skb, nla) cancel nested attribute construction 121 * nla_put_empty_nest(skb, type) create an empty nest 122 * 123 * Attribute Length Calculations: 124 * nla_attr_size(payload) length of attribute w/o padding 125 * nla_total_size(payload) length of attribute w/ padding 126 * nla_padlen(payload) length of padding 127 * 128 * Attribute Payload Access: 129 * nla_data(nla) head of attribute payload 130 * nla_len(nla) length of attribute payload 131 * 132 * Attribute Payload Access for Basic Types: 133 * nla_get_uint(nla) get payload for a uint attribute 134 * nla_get_sint(nla) get payload for a sint attribute 135 * nla_get_u8(nla) get payload for a u8 attribute 136 * nla_get_u16(nla) get payload for a u16 attribute 137 * nla_get_u32(nla) get payload for a u32 attribute 138 * nla_get_u64(nla) get payload for a u64 attribute 139 * nla_get_s8(nla) get payload for a s8 attribute 140 * nla_get_s16(nla) get payload for a s16 attribute 141 * nla_get_s32(nla) get payload for a s32 attribute 142 * nla_get_s64(nla) get payload for a s64 attribute 143 * nla_get_flag(nla) return 1 if flag is true 144 * nla_get_msecs(nla) get payload for a msecs attribute 145 * 146 * The same functions also exist with _default(). 147 * 148 * Attribute Misc: 149 * nla_memcpy(dest, nla, count) copy attribute into memory 150 * nla_memcmp(nla, data, size) compare attribute with memory area 151 * nla_strscpy(dst, nla, size) copy attribute to a sized string 152 * nla_strcmp(nla, str) compare attribute with string 153 * 154 * Attribute Parsing: 155 * nla_ok(nla, remaining) does nla fit into remaining bytes? 156 * nla_next(nla, remaining) get next netlink attribute 157 * nla_validate() validate a stream of attributes 158 * nla_validate_nested() validate a stream of nested attributes 159 * nla_find() find attribute in stream of attributes 160 * nla_find_nested() find attribute in nested attributes 161 * nla_parse() parse and validate stream of attrs 162 * nla_parse_nested() parse nested attributes 163 * nla_for_each_attr() loop over all attributes 164 * nla_for_each_attr_type() loop over all attributes with the 165 * given type 166 * nla_for_each_nested() loop over the nested attributes 167 * nla_for_each_nested_type() loop over the nested attributes with 168 * the given type 169 *========================================================================= 170 */ 171 172 /** 173 * Standard attribute types to specify validation policy 174 */ 175 enum { 176 NLA_UNSPEC, 177 NLA_U8, 178 NLA_U16, 179 NLA_U32, 180 NLA_U64, 181 NLA_STRING, 182 NLA_FLAG, 183 NLA_MSECS, 184 NLA_NESTED, 185 NLA_NESTED_ARRAY, 186 NLA_NUL_STRING, 187 NLA_BINARY, 188 NLA_S8, 189 NLA_S16, 190 NLA_S32, 191 NLA_S64, 192 NLA_BITFIELD32, 193 NLA_REJECT, 194 NLA_BE16, 195 NLA_BE32, 196 NLA_SINT, 197 NLA_UINT, 198 __NLA_TYPE_MAX, 199 }; 200 201 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) 202 203 struct netlink_range_validation { 204 u64 min, max; 205 }; 206 207 struct netlink_range_validation_signed { 208 s64 min, max; 209 }; 210 211 enum nla_policy_validation { 212 NLA_VALIDATE_NONE, 213 NLA_VALIDATE_RANGE, 214 NLA_VALIDATE_RANGE_WARN_TOO_LONG, 215 NLA_VALIDATE_MIN, 216 NLA_VALIDATE_MAX, 217 NLA_VALIDATE_MASK, 218 NLA_VALIDATE_RANGE_PTR, 219 NLA_VALIDATE_FUNCTION, 220 }; 221 222 /** 223 * struct nla_policy - attribute validation policy 224 * @type: Type of attribute or NLA_UNSPEC 225 * @validation_type: type of attribute validation done in addition to 226 * type-specific validation (e.g. range, function call), see 227 * &enum nla_policy_validation 228 * @len: Type specific length of payload 229 * 230 * Policies are defined as arrays of this struct, the array must be 231 * accessible by attribute type up to the highest identifier to be expected. 232 * 233 * Meaning of `len' field: 234 * NLA_STRING Maximum length of string 235 * NLA_NUL_STRING Maximum length of string (excluding NUL) 236 * NLA_FLAG Unused 237 * NLA_BINARY Maximum length of attribute payload 238 * (but see also below with the validation type) 239 * NLA_NESTED, 240 * NLA_NESTED_ARRAY Length verification is done by checking len of 241 * nested header (or empty); len field is used if 242 * nested_policy is also used, for the max attr 243 * number in the nested policy. 244 * NLA_SINT, NLA_UINT, 245 * NLA_U8, NLA_U16, 246 * NLA_U32, NLA_U64, 247 * NLA_S8, NLA_S16, 248 * NLA_S32, NLA_S64, 249 * NLA_BE16, NLA_BE32, 250 * NLA_MSECS Leaving the length field zero will verify the 251 * given type fits, using it verifies minimum length 252 * just like "All other" 253 * NLA_BITFIELD32 Unused 254 * NLA_REJECT Unused 255 * All other Minimum length of attribute payload 256 * 257 * Meaning of validation union: 258 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and 259 * `bitfield32_valid' is the u32 value of valid flags 260 * NLA_REJECT This attribute is always rejected and `reject_message' 261 * may point to a string to report as the error instead 262 * of the generic one in extended ACK. 263 * NLA_NESTED `nested_policy' to a nested policy to validate, must 264 * also set `len' to the max attribute number. Use the 265 * provided NLA_POLICY_NESTED() macro. 266 * Note that nla_parse() will validate, but of course not 267 * parse, the nested sub-policies. 268 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate, 269 * must also set `len' to the max attribute number. Use 270 * the provided NLA_POLICY_NESTED_ARRAY() macro. 271 * The difference to NLA_NESTED is the structure: 272 * NLA_NESTED has the nested attributes directly inside 273 * while an array has the nested attributes at another 274 * level down and the attribute types directly in the 275 * nesting don't matter. 276 * NLA_UINT, 277 * NLA_U8, 278 * NLA_U16, 279 * NLA_U32, 280 * NLA_U64, 281 * NLA_BE16, 282 * NLA_BE32, 283 * NLA_SINT, 284 * NLA_S8, 285 * NLA_S16, 286 * NLA_S32, 287 * NLA_S64 The `min' and `max' fields are used depending on the 288 * validation_type field, if that is min/max/range then 289 * the min, max or both are used (respectively) to check 290 * the value of the integer attribute. 291 * Note that in the interest of code simplicity and 292 * struct size both limits are s16, so you cannot 293 * enforce a range that doesn't fall within the range 294 * of s16 - do that using the NLA_POLICY_FULL_RANGE() 295 * or NLA_POLICY_FULL_RANGE_SIGNED() macros instead. 296 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and 297 * NLA_POLICY_RANGE() macros. 298 * NLA_UINT, 299 * NLA_U8, 300 * NLA_U16, 301 * NLA_U32, 302 * NLA_U64 If the validation_type field instead is set to 303 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer 304 * to a struct netlink_range_validation that indicates 305 * the min/max values. 306 * Use NLA_POLICY_FULL_RANGE(). 307 * NLA_SINT, 308 * NLA_S8, 309 * NLA_S16, 310 * NLA_S32, 311 * NLA_S64 If the validation_type field instead is set to 312 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a 313 * pointer to a struct netlink_range_validation_signed 314 * that indicates the min/max values. 315 * Use NLA_POLICY_FULL_RANGE_SIGNED(). 316 * 317 * NLA_BINARY If the validation type is like the ones for integers 318 * above, then the min/max length (not value like for 319 * integers) of the attribute is enforced. 320 * 321 * All other Unused - but note that it's a union 322 * 323 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN: 324 * NLA_BINARY Validation function called for the attribute. 325 * All other Unused - but note that it's a union 326 * 327 * Example: 328 * 329 * static const u32 myvalidflags = 0xff231023; 330 * 331 * static const struct nla_policy my_policy[ATTR_MAX+1] = { 332 * [ATTR_FOO] = { .type = NLA_U16 }, 333 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, 334 * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)), 335 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags), 336 * }; 337 */ 338 struct nla_policy { 339 u8 type; 340 u8 validation_type; 341 u16 len; 342 union { 343 /** 344 * @strict_start_type: first attribute to validate strictly 345 * 346 * This entry is special, and used for the attribute at index 0 347 * only, and specifies special data about the policy, namely it 348 * specifies the "boundary type" where strict length validation 349 * starts for any attribute types >= this value, also, strict 350 * nesting validation starts here. 351 * 352 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT 353 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to 354 * get the previous pure { .len = xyz } behaviour. The advantage 355 * of this is that types not specified in the policy will be 356 * rejected. 357 * 358 * For completely new families it should be set to 1 so that the 359 * validation is enforced for all attributes. For existing ones 360 * it should be set at least when new attributes are added to 361 * the enum used by the policy, and be set to the new value that 362 * was added to enforce strict validation from thereon. 363 */ 364 u16 strict_start_type; 365 366 /* private: use NLA_POLICY_*() to set */ 367 const u32 bitfield32_valid; 368 const u32 mask; 369 const char *reject_message; 370 const struct nla_policy *nested_policy; 371 const struct netlink_range_validation *range; 372 const struct netlink_range_validation_signed *range_signed; 373 struct { 374 s16 min, max; 375 }; 376 int (*validate)(const struct nlattr *attr, 377 struct netlink_ext_ack *extack); 378 }; 379 }; 380 381 #define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) 382 #define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) 383 384 #define _NLA_POLICY_NESTED(maxattr, policy) \ 385 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr } 386 #define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ 387 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr } 388 #define NLA_POLICY_NESTED(policy) \ 389 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy) 390 #define NLA_POLICY_NESTED_ARRAY(policy) \ 391 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy) 392 #define NLA_POLICY_BITFIELD32(valid) \ 393 { .type = NLA_BITFIELD32, .bitfield32_valid = valid } 394 395 #define __NLA_IS_UINT_TYPE(tp) \ 396 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || \ 397 tp == NLA_U64 || tp == NLA_UINT || \ 398 tp == NLA_BE16 || tp == NLA_BE32) 399 #define __NLA_IS_SINT_TYPE(tp) \ 400 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64 || \ 401 tp == NLA_SINT) 402 403 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition)) 404 #define NLA_ENSURE_UINT_TYPE(tp) \ 405 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp) 406 #define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \ 407 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \ 408 tp == NLA_MSECS || \ 409 tp == NLA_BINARY) + tp) 410 #define NLA_ENSURE_SINT_TYPE(tp) \ 411 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp) 412 #define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \ 413 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \ 414 __NLA_IS_SINT_TYPE(tp) || \ 415 tp == NLA_MSECS || \ 416 tp == NLA_BINARY) + tp) 417 #define NLA_ENSURE_NO_VALIDATION_PTR(tp) \ 418 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \ 419 tp != NLA_REJECT && \ 420 tp != NLA_NESTED && \ 421 tp != NLA_NESTED_ARRAY) + tp) 422 423 #define NLA_POLICY_RANGE(tp, _min, _max) { \ 424 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 425 .validation_type = NLA_VALIDATE_RANGE, \ 426 .min = _min, \ 427 .max = _max \ 428 } 429 430 #define NLA_POLICY_FULL_RANGE(tp, _range) { \ 431 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \ 432 .validation_type = NLA_VALIDATE_RANGE_PTR, \ 433 .range = _range, \ 434 } 435 436 #define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \ 437 .type = NLA_ENSURE_SINT_TYPE(tp), \ 438 .validation_type = NLA_VALIDATE_RANGE_PTR, \ 439 .range_signed = _range, \ 440 } 441 442 #define NLA_POLICY_MIN(tp, _min) { \ 443 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 444 .validation_type = NLA_VALIDATE_MIN, \ 445 .min = _min, \ 446 } 447 448 #define NLA_POLICY_MAX(tp, _max) { \ 449 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 450 .validation_type = NLA_VALIDATE_MAX, \ 451 .max = _max, \ 452 } 453 454 #define NLA_POLICY_MASK(tp, _mask) { \ 455 .type = NLA_ENSURE_UINT_TYPE(tp), \ 456 .validation_type = NLA_VALIDATE_MASK, \ 457 .mask = _mask, \ 458 } 459 460 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \ 461 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \ 462 .validation_type = NLA_VALIDATE_FUNCTION, \ 463 .validate = fn, \ 464 .len = __VA_ARGS__ + 0, \ 465 } 466 467 #define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len) 468 #define NLA_POLICY_EXACT_LEN_WARN(_len) { \ 469 .type = NLA_BINARY, \ 470 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \ 471 .min = _len, \ 472 .max = _len \ 473 } 474 #define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len) 475 #define NLA_POLICY_MAX_LEN(_len) NLA_POLICY_MAX(NLA_BINARY, _len) 476 477 /** 478 * struct nl_info - netlink source information 479 * @nlh: Netlink message header of original request 480 * @nl_net: Network namespace 481 * @portid: Netlink PORTID of requesting application 482 * @skip_notify: Skip netlink notifications to user space 483 * @skip_notify_kernel: Skip selected in-kernel notifications 484 */ 485 struct nl_info { 486 struct nlmsghdr *nlh; 487 struct net *nl_net; 488 u32 portid; 489 u8 skip_notify:1, 490 skip_notify_kernel:1; 491 }; 492 493 /** 494 * enum netlink_validation - netlink message/attribute validation levels 495 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about 496 * extra data at the end of the message, attributes being longer than 497 * they should be, or unknown attributes being present. 498 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing. 499 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING 500 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict(). 501 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy. 502 * This can safely be set by the kernel when the given policy has no 503 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries 504 * are enforced going forward. 505 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g. 506 * U8, U16, U32 must have exact size, etc.) 507 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY) 508 * and unset for other policies. 509 */ 510 enum netlink_validation { 511 NL_VALIDATE_LIBERAL = 0, 512 NL_VALIDATE_TRAILING = BIT(0), 513 NL_VALIDATE_MAXTYPE = BIT(1), 514 NL_VALIDATE_UNSPEC = BIT(2), 515 NL_VALIDATE_STRICT_ATTRS = BIT(3), 516 NL_VALIDATE_NESTED = BIT(4), 517 }; 518 519 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\ 520 NL_VALIDATE_MAXTYPE) 521 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\ 522 NL_VALIDATE_MAXTYPE |\ 523 NL_VALIDATE_UNSPEC |\ 524 NL_VALIDATE_STRICT_ATTRS |\ 525 NL_VALIDATE_NESTED) 526 527 int netlink_rcv_skb(struct sk_buff *skb, 528 int (*cb)(struct sk_buff *, struct nlmsghdr *, 529 struct netlink_ext_ack *)); 530 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, 531 unsigned int group, int report, gfp_t flags); 532 533 int __nla_validate(const struct nlattr *head, int len, int maxtype, 534 const struct nla_policy *policy, unsigned int validate, 535 struct netlink_ext_ack *extack); 536 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, 537 int len, const struct nla_policy *policy, unsigned int validate, 538 struct netlink_ext_ack *extack); 539 int nla_policy_len(const struct nla_policy *, int); 540 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype); 541 ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize); 542 char *nla_strdup(const struct nlattr *nla, gfp_t flags); 543 int nla_memcpy(void *dest, const struct nlattr *src, int count); 544 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size); 545 int nla_strcmp(const struct nlattr *nla, const char *str); 546 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 547 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, 548 int attrlen, int padattr); 549 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 550 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 551 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, 552 int attrlen, int padattr); 553 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 554 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, 555 const void *data); 556 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 557 const void *data, int padattr); 558 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 559 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); 560 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 561 const void *data, int padattr); 562 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 563 int nla_append(struct sk_buff *skb, int attrlen, const void *data); 564 565 /************************************************************************** 566 * Netlink Messages 567 **************************************************************************/ 568 569 /** 570 * nlmsg_msg_size - length of netlink message not including padding 571 * @payload: length of message payload 572 */ 573 static inline int nlmsg_msg_size(int payload) 574 { 575 return NLMSG_HDRLEN + payload; 576 } 577 578 /** 579 * nlmsg_total_size - length of netlink message including padding 580 * @payload: length of message payload 581 */ 582 static inline int nlmsg_total_size(int payload) 583 { 584 return NLMSG_ALIGN(nlmsg_msg_size(payload)); 585 } 586 587 /** 588 * nlmsg_padlen - length of padding at the message's tail 589 * @payload: length of message payload 590 */ 591 static inline int nlmsg_padlen(int payload) 592 { 593 return nlmsg_total_size(payload) - nlmsg_msg_size(payload); 594 } 595 596 /** 597 * nlmsg_data - head of message payload 598 * @nlh: netlink message header 599 */ 600 static inline void *nlmsg_data(const struct nlmsghdr *nlh) 601 { 602 return (unsigned char *) nlh + NLMSG_HDRLEN; 603 } 604 605 /** 606 * nlmsg_len - length of message payload 607 * @nlh: netlink message header 608 */ 609 static inline int nlmsg_len(const struct nlmsghdr *nlh) 610 { 611 return nlh->nlmsg_len - NLMSG_HDRLEN; 612 } 613 614 /** 615 * nlmsg_payload - message payload if the data fits in the len 616 * @nlh: netlink message header 617 * @len: struct length 618 * 619 * Returns: The netlink message payload/data if the length is sufficient, 620 * otherwise NULL. 621 */ 622 static inline void *nlmsg_payload(const struct nlmsghdr *nlh, size_t len) 623 { 624 if (nlh->nlmsg_len < nlmsg_msg_size(len)) 625 return NULL; 626 627 return nlmsg_data(nlh); 628 } 629 630 /** 631 * nlmsg_attrdata - head of attributes data 632 * @nlh: netlink message header 633 * @hdrlen: length of family specific header 634 */ 635 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 636 int hdrlen) 637 { 638 unsigned char *data = nlmsg_data(nlh); 639 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); 640 } 641 642 /** 643 * nlmsg_attrlen - length of attributes data 644 * @nlh: netlink message header 645 * @hdrlen: length of family specific header 646 */ 647 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) 648 { 649 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); 650 } 651 652 /** 653 * nlmsg_ok - check if the netlink message fits into the remaining bytes 654 * @nlh: netlink message header 655 * @remaining: number of bytes remaining in message stream 656 */ 657 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) 658 { 659 return (remaining >= (int) sizeof(struct nlmsghdr) && 660 nlh->nlmsg_len >= sizeof(struct nlmsghdr) && 661 nlh->nlmsg_len <= remaining); 662 } 663 664 /** 665 * nlmsg_next - next netlink message in message stream 666 * @nlh: netlink message header 667 * @remaining: number of bytes remaining in message stream 668 * 669 * Returns: the next netlink message in the message stream and 670 * decrements remaining by the size of the current message. 671 */ 672 static inline struct nlmsghdr * 673 nlmsg_next(const struct nlmsghdr *nlh, int *remaining) 674 { 675 int totlen = NLMSG_ALIGN(nlh->nlmsg_len); 676 677 *remaining -= totlen; 678 679 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); 680 } 681 682 /** 683 * nla_parse - Parse a stream of attributes into a tb buffer 684 * @tb: destination array with maxtype+1 elements 685 * @maxtype: maximum attribute type to be expected 686 * @head: head of attribute stream 687 * @len: length of attribute stream 688 * @policy: validation policy 689 * @extack: extended ACK pointer 690 * 691 * Parses a stream of attributes and stores a pointer to each attribute in 692 * the tb array accessible via the attribute type. Attributes with a type 693 * exceeding maxtype will be rejected, policy must be specified, attributes 694 * will be validated in the strictest way possible. 695 * 696 * Returns: 0 on success or a negative error code. 697 */ 698 static inline int nla_parse(struct nlattr **tb, int maxtype, 699 const struct nlattr *head, int len, 700 const struct nla_policy *policy, 701 struct netlink_ext_ack *extack) 702 { 703 return __nla_parse(tb, maxtype, head, len, policy, 704 NL_VALIDATE_STRICT, extack); 705 } 706 707 /** 708 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer 709 * @tb: destination array with maxtype+1 elements 710 * @maxtype: maximum attribute type to be expected 711 * @head: head of attribute stream 712 * @len: length of attribute stream 713 * @policy: validation policy 714 * @extack: extended ACK pointer 715 * 716 * Parses a stream of attributes and stores a pointer to each attribute in 717 * the tb array accessible via the attribute type. Attributes with a type 718 * exceeding maxtype will be ignored and attributes from the policy are not 719 * always strictly validated (only for new attributes). 720 * 721 * Returns: 0 on success or a negative error code. 722 */ 723 static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype, 724 const struct nlattr *head, int len, 725 const struct nla_policy *policy, 726 struct netlink_ext_ack *extack) 727 { 728 return __nla_parse(tb, maxtype, head, len, policy, 729 NL_VALIDATE_LIBERAL, extack); 730 } 731 732 /** 733 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer 734 * @tb: destination array with maxtype+1 elements 735 * @maxtype: maximum attribute type to be expected 736 * @head: head of attribute stream 737 * @len: length of attribute stream 738 * @policy: validation policy 739 * @extack: extended ACK pointer 740 * 741 * Parses a stream of attributes and stores a pointer to each attribute in 742 * the tb array accessible via the attribute type. Attributes with a type 743 * exceeding maxtype will be rejected as well as trailing data, but the 744 * policy is not completely strictly validated (only for new attributes). 745 * 746 * Returns: 0 on success or a negative error code. 747 */ 748 static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype, 749 const struct nlattr *head, 750 int len, 751 const struct nla_policy *policy, 752 struct netlink_ext_ack *extack) 753 { 754 return __nla_parse(tb, maxtype, head, len, policy, 755 NL_VALIDATE_DEPRECATED_STRICT, extack); 756 } 757 758 /** 759 * __nlmsg_parse - parse attributes of a netlink message 760 * @nlh: netlink message header 761 * @hdrlen: length of family specific header 762 * @tb: destination array with maxtype+1 elements 763 * @maxtype: maximum attribute type to be expected 764 * @policy: validation policy 765 * @validate: validation strictness 766 * @extack: extended ACK report struct 767 * 768 * See nla_parse() 769 */ 770 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 771 struct nlattr *tb[], int maxtype, 772 const struct nla_policy *policy, 773 unsigned int validate, 774 struct netlink_ext_ack *extack) 775 { 776 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) { 777 NL_SET_ERR_MSG(extack, "Invalid header length"); 778 return -EINVAL; 779 } 780 781 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 782 nlmsg_attrlen(nlh, hdrlen), policy, validate, 783 extack); 784 } 785 786 /** 787 * nlmsg_parse - parse attributes of a netlink message 788 * @nlh: netlink message header 789 * @hdrlen: length of family specific header 790 * @tb: destination array with maxtype+1 elements 791 * @maxtype: maximum attribute type to be expected 792 * @policy: validation policy 793 * @extack: extended ACK report struct 794 * 795 * See nla_parse() 796 */ 797 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 798 struct nlattr *tb[], int maxtype, 799 const struct nla_policy *policy, 800 struct netlink_ext_ack *extack) 801 { 802 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 803 NL_VALIDATE_STRICT, extack); 804 } 805 806 /** 807 * nlmsg_parse_deprecated - parse attributes of a netlink message 808 * @nlh: netlink message header 809 * @hdrlen: length of family specific header 810 * @tb: destination array with maxtype+1 elements 811 * @maxtype: maximum attribute type to be expected 812 * @policy: validation policy 813 * @extack: extended ACK report struct 814 * 815 * See nla_parse_deprecated() 816 */ 817 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen, 818 struct nlattr *tb[], int maxtype, 819 const struct nla_policy *policy, 820 struct netlink_ext_ack *extack) 821 { 822 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 823 NL_VALIDATE_LIBERAL, extack); 824 } 825 826 /** 827 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message 828 * @nlh: netlink message header 829 * @hdrlen: length of family specific header 830 * @tb: destination array with maxtype+1 elements 831 * @maxtype: maximum attribute type to be expected 832 * @policy: validation policy 833 * @extack: extended ACK report struct 834 * 835 * See nla_parse_deprecated_strict() 836 */ 837 static inline int 838 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen, 839 struct nlattr *tb[], int maxtype, 840 const struct nla_policy *policy, 841 struct netlink_ext_ack *extack) 842 { 843 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 844 NL_VALIDATE_DEPRECATED_STRICT, extack); 845 } 846 847 /** 848 * nlmsg_find_attr - find a specific attribute in a netlink message 849 * @nlh: netlink message header 850 * @hdrlen: length of family specific header 851 * @attrtype: type of attribute to look for 852 * 853 * Returns: the first attribute which matches the specified type. 854 */ 855 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh, 856 int hdrlen, int attrtype) 857 { 858 return nla_find(nlmsg_attrdata(nlh, hdrlen), 859 nlmsg_attrlen(nlh, hdrlen), attrtype); 860 } 861 862 /** 863 * nla_validate_deprecated - Validate a stream of attributes 864 * @head: head of attribute stream 865 * @len: length of attribute stream 866 * @maxtype: maximum attribute type to be expected 867 * @policy: validation policy 868 * @extack: extended ACK report struct 869 * 870 * Validates all attributes in the specified attribute stream against the 871 * specified policy. Validation is done in liberal mode. 872 * See documentation of struct nla_policy for more details. 873 * 874 * Returns: 0 on success or a negative error code. 875 */ 876 static inline int nla_validate_deprecated(const struct nlattr *head, int len, 877 int maxtype, 878 const struct nla_policy *policy, 879 struct netlink_ext_ack *extack) 880 { 881 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL, 882 extack); 883 } 884 885 /** 886 * nla_validate - Validate a stream of attributes 887 * @head: head of attribute stream 888 * @len: length of attribute stream 889 * @maxtype: maximum attribute type to be expected 890 * @policy: validation policy 891 * @extack: extended ACK report struct 892 * 893 * Validates all attributes in the specified attribute stream against the 894 * specified policy. Validation is done in strict mode. 895 * See documentation of struct nla_policy for more details. 896 * 897 * Returns: 0 on success or a negative error code. 898 */ 899 static inline int nla_validate(const struct nlattr *head, int len, int maxtype, 900 const struct nla_policy *policy, 901 struct netlink_ext_ack *extack) 902 { 903 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT, 904 extack); 905 } 906 907 /** 908 * nlmsg_validate_deprecated - validate a netlink message including attributes 909 * @nlh: netlinket message header 910 * @hdrlen: length of family specific header 911 * @maxtype: maximum attribute type to be expected 912 * @policy: validation policy 913 * @extack: extended ACK report struct 914 */ 915 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh, 916 int hdrlen, int maxtype, 917 const struct nla_policy *policy, 918 struct netlink_ext_ack *extack) 919 { 920 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 921 return -EINVAL; 922 923 return __nla_validate(nlmsg_attrdata(nlh, hdrlen), 924 nlmsg_attrlen(nlh, hdrlen), maxtype, 925 policy, NL_VALIDATE_LIBERAL, extack); 926 } 927 928 929 930 /** 931 * nlmsg_report - need to report back to application? 932 * @nlh: netlink message header 933 * 934 * Returns: 1 if a report back to the application is requested. 935 */ 936 static inline int nlmsg_report(const struct nlmsghdr *nlh) 937 { 938 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0; 939 } 940 941 /** 942 * nlmsg_seq - return the seq number of netlink message 943 * @nlh: netlink message header 944 * 945 * Returns: 0 if netlink message is NULL 946 */ 947 static inline u32 nlmsg_seq(const struct nlmsghdr *nlh) 948 { 949 return nlh ? nlh->nlmsg_seq : 0; 950 } 951 952 /** 953 * nlmsg_for_each_attr - iterate over a stream of attributes 954 * @pos: loop counter, set to current attribute 955 * @nlh: netlink message header 956 * @hdrlen: length of family specific header 957 * @rem: initialized to len, holds bytes currently remaining in stream 958 */ 959 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ 960 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ 961 nlmsg_attrlen(nlh, hdrlen), rem) 962 963 /** 964 * nlmsg_put - Add a new netlink message to an skb 965 * @skb: socket buffer to store message in 966 * @portid: netlink PORTID of requesting application 967 * @seq: sequence number of message 968 * @type: message type 969 * @payload: length of message payload 970 * @flags: message flags 971 * 972 * Returns: NULL if the tailroom of the skb is insufficient to store 973 * the message header and payload. 974 */ 975 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, 976 int type, int payload, int flags) 977 { 978 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) 979 return NULL; 980 981 return __nlmsg_put(skb, portid, seq, type, payload, flags); 982 } 983 984 /** 985 * nlmsg_append - Add more data to a nlmsg in a skb 986 * @skb: socket buffer to store message in 987 * @size: length of message payload 988 * 989 * Append data to an existing nlmsg, used when constructing a message 990 * with multiple fixed-format headers (which is rare). 991 * Returns: NULL if the tailroom of the skb is insufficient to store 992 * the extra payload. 993 */ 994 static inline void *nlmsg_append(struct sk_buff *skb, u32 size) 995 { 996 if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size))) 997 return NULL; 998 999 if (NLMSG_ALIGN(size) - size) 1000 memset(skb_tail_pointer(skb) + size, 0, 1001 NLMSG_ALIGN(size) - size); 1002 return __skb_put(skb, NLMSG_ALIGN(size)); 1003 } 1004 1005 /** 1006 * nlmsg_put_answer - Add a new callback based netlink message to an skb 1007 * @skb: socket buffer to store message in 1008 * @cb: netlink callback 1009 * @type: message type 1010 * @payload: length of message payload 1011 * @flags: message flags 1012 * 1013 * Returns: NULL if the tailroom of the skb is insufficient to store 1014 * the message header and payload. 1015 */ 1016 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, 1017 struct netlink_callback *cb, 1018 int type, int payload, 1019 int flags) 1020 { 1021 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 1022 type, payload, flags); 1023 } 1024 1025 /** 1026 * nlmsg_new - Allocate a new netlink message 1027 * @payload: size of the message payload 1028 * @flags: the type of memory to allocate. 1029 * 1030 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known 1031 * and a good default is needed. 1032 */ 1033 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) 1034 { 1035 return alloc_skb(nlmsg_total_size(payload), flags); 1036 } 1037 1038 /** 1039 * nlmsg_new_large - Allocate a new netlink message with non-contiguous 1040 * physical memory 1041 * @payload: size of the message payload 1042 * 1043 * The allocated skb is unable to have frag page for shinfo->frags*, 1044 * as the NULL setting for skb->head in netlink_skb_destructor() will 1045 * bypass most of the handling in skb_release_data() 1046 */ 1047 static inline struct sk_buff *nlmsg_new_large(size_t payload) 1048 { 1049 return netlink_alloc_large_skb(nlmsg_total_size(payload), 0); 1050 } 1051 1052 /** 1053 * nlmsg_end - Finalize a netlink message 1054 * @skb: socket buffer the message is stored in 1055 * @nlh: netlink message header 1056 * 1057 * Corrects the netlink message header to include the appended 1058 * attributes. Only necessary if attributes have been added to 1059 * the message. 1060 */ 1061 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 1062 { 1063 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 1064 } 1065 1066 /** 1067 * nlmsg_get_pos - return current position in netlink message 1068 * @skb: socket buffer the message is stored in 1069 * 1070 * Returns: a pointer to the current tail of the message. 1071 */ 1072 static inline void *nlmsg_get_pos(struct sk_buff *skb) 1073 { 1074 return skb_tail_pointer(skb); 1075 } 1076 1077 /** 1078 * nlmsg_trim - Trim message to a mark 1079 * @skb: socket buffer the message is stored in 1080 * @mark: mark to trim to 1081 * 1082 * Trims the message to the provided mark. 1083 */ 1084 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 1085 { 1086 if (mark) { 1087 WARN_ON((unsigned char *) mark < skb->data); 1088 skb_trim(skb, (unsigned char *) mark - skb->data); 1089 } 1090 } 1091 1092 /** 1093 * nlmsg_cancel - Cancel construction of a netlink message 1094 * @skb: socket buffer the message is stored in 1095 * @nlh: netlink message header 1096 * 1097 * Removes the complete netlink message including all 1098 * attributes from the socket buffer again. 1099 */ 1100 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 1101 { 1102 nlmsg_trim(skb, nlh); 1103 } 1104 1105 /** 1106 * nlmsg_free - drop a netlink message 1107 * @skb: socket buffer of netlink message 1108 */ 1109 static inline void nlmsg_free(struct sk_buff *skb) 1110 { 1111 kfree_skb(skb); 1112 } 1113 1114 /** 1115 * nlmsg_consume - free a netlink message 1116 * @skb: socket buffer of netlink message 1117 */ 1118 static inline void nlmsg_consume(struct sk_buff *skb) 1119 { 1120 consume_skb(skb); 1121 } 1122 1123 /** 1124 * nlmsg_multicast_filtered - multicast a netlink message with filter function 1125 * @sk: netlink socket to spread messages to 1126 * @skb: netlink message as socket buffer 1127 * @portid: own netlink portid to avoid sending to yourself 1128 * @group: multicast group id 1129 * @flags: allocation flags 1130 * @filter: filter function 1131 * @filter_data: filter function private data 1132 * 1133 * Return: 0 on success, negative error code for failure. 1134 */ 1135 static inline int nlmsg_multicast_filtered(struct sock *sk, struct sk_buff *skb, 1136 u32 portid, unsigned int group, 1137 gfp_t flags, 1138 netlink_filter_fn filter, 1139 void *filter_data) 1140 { 1141 int err; 1142 1143 NETLINK_CB(skb).dst_group = group; 1144 1145 err = netlink_broadcast_filtered(sk, skb, portid, group, flags, 1146 filter, filter_data); 1147 if (err > 0) 1148 err = 0; 1149 1150 return err; 1151 } 1152 1153 /** 1154 * nlmsg_multicast - multicast a netlink message 1155 * @sk: netlink socket to spread messages to 1156 * @skb: netlink message as socket buffer 1157 * @portid: own netlink portid to avoid sending to yourself 1158 * @group: multicast group id 1159 * @flags: allocation flags 1160 */ 1161 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 1162 u32 portid, unsigned int group, gfp_t flags) 1163 { 1164 return nlmsg_multicast_filtered(sk, skb, portid, group, flags, 1165 NULL, NULL); 1166 } 1167 1168 /** 1169 * nlmsg_unicast - unicast a netlink message 1170 * @sk: netlink socket to spread message to 1171 * @skb: netlink message as socket buffer 1172 * @portid: netlink portid of the destination socket 1173 */ 1174 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid) 1175 { 1176 int err; 1177 1178 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT); 1179 if (err > 0) 1180 err = 0; 1181 1182 return err; 1183 } 1184 1185 /** 1186 * nlmsg_for_each_msg - iterate over a stream of messages 1187 * @pos: loop counter, set to current message 1188 * @head: head of message stream 1189 * @len: length of message stream 1190 * @rem: initialized to len, holds bytes currently remaining in stream 1191 */ 1192 #define nlmsg_for_each_msg(pos, head, len, rem) \ 1193 for (pos = head, rem = len; \ 1194 nlmsg_ok(pos, rem); \ 1195 pos = nlmsg_next(pos, &(rem))) 1196 1197 /** 1198 * nl_dump_check_consistent - check if sequence is consistent and advertise if not 1199 * @cb: netlink callback structure that stores the sequence number 1200 * @nlh: netlink message header to write the flag to 1201 * 1202 * This function checks if the sequence (generation) number changed during dump 1203 * and if it did, advertises it in the netlink message header. 1204 * 1205 * The correct way to use it is to set cb->seq to the generation counter when 1206 * all locks for dumping have been acquired, and then call this function for 1207 * each message that is generated. 1208 * 1209 * Note that due to initialisation concerns, 0 is an invalid sequence number 1210 * and must not be used by code that uses this functionality. 1211 */ 1212 static inline void 1213 nl_dump_check_consistent(struct netlink_callback *cb, 1214 struct nlmsghdr *nlh) 1215 { 1216 if (cb->prev_seq && cb->seq != cb->prev_seq) 1217 nlh->nlmsg_flags |= NLM_F_DUMP_INTR; 1218 cb->prev_seq = cb->seq; 1219 } 1220 1221 /************************************************************************** 1222 * Netlink Attributes 1223 **************************************************************************/ 1224 1225 /** 1226 * nla_attr_size - length of attribute not including padding 1227 * @payload: length of payload 1228 */ 1229 static inline int nla_attr_size(int payload) 1230 { 1231 return NLA_HDRLEN + payload; 1232 } 1233 1234 /** 1235 * nla_total_size - total length of attribute including padding 1236 * @payload: length of payload 1237 */ 1238 static inline int nla_total_size(int payload) 1239 { 1240 return NLA_ALIGN(nla_attr_size(payload)); 1241 } 1242 1243 /** 1244 * nla_padlen - length of padding at the tail of attribute 1245 * @payload: length of payload 1246 */ 1247 static inline int nla_padlen(int payload) 1248 { 1249 return nla_total_size(payload) - nla_attr_size(payload); 1250 } 1251 1252 /** 1253 * nla_type - attribute type 1254 * @nla: netlink attribute 1255 */ 1256 static inline int nla_type(const struct nlattr *nla) 1257 { 1258 return nla->nla_type & NLA_TYPE_MASK; 1259 } 1260 1261 /** 1262 * nla_data - head of payload 1263 * @nla: netlink attribute 1264 */ 1265 static inline void *nla_data(const struct nlattr *nla) 1266 { 1267 return (char *) nla + NLA_HDRLEN; 1268 } 1269 1270 /** 1271 * nla_len - length of payload 1272 * @nla: netlink attribute 1273 */ 1274 static inline u16 nla_len(const struct nlattr *nla) 1275 { 1276 return nla->nla_len - NLA_HDRLEN; 1277 } 1278 1279 /** 1280 * nla_ok - check if the netlink attribute fits into the remaining bytes 1281 * @nla: netlink attribute 1282 * @remaining: number of bytes remaining in attribute stream 1283 */ 1284 static inline int nla_ok(const struct nlattr *nla, int remaining) 1285 { 1286 return remaining >= (int) sizeof(*nla) && 1287 nla->nla_len >= sizeof(*nla) && 1288 nla->nla_len <= remaining; 1289 } 1290 1291 /** 1292 * nla_next - next netlink attribute in attribute stream 1293 * @nla: netlink attribute 1294 * @remaining: number of bytes remaining in attribute stream 1295 * 1296 * Returns: the next netlink attribute in the attribute stream and 1297 * decrements remaining by the size of the current attribute. 1298 */ 1299 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 1300 { 1301 unsigned int totlen = NLA_ALIGN(nla->nla_len); 1302 1303 *remaining -= totlen; 1304 return (struct nlattr *) ((char *) nla + totlen); 1305 } 1306 1307 /** 1308 * nla_find_nested - find attribute in a set of nested attributes 1309 * @nla: attribute containing the nested attributes 1310 * @attrtype: type of attribute to look for 1311 * 1312 * Returns: the first attribute which matches the specified type. 1313 */ 1314 static inline struct nlattr * 1315 nla_find_nested(const struct nlattr *nla, int attrtype) 1316 { 1317 return nla_find(nla_data(nla), nla_len(nla), attrtype); 1318 } 1319 1320 /** 1321 * nla_parse_nested - parse nested attributes 1322 * @tb: destination array with maxtype+1 elements 1323 * @maxtype: maximum attribute type to be expected 1324 * @nla: attribute containing the nested attributes 1325 * @policy: validation policy 1326 * @extack: extended ACK report struct 1327 * 1328 * See nla_parse() 1329 */ 1330 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 1331 const struct nlattr *nla, 1332 const struct nla_policy *policy, 1333 struct netlink_ext_ack *extack) 1334 { 1335 if (!(nla->nla_type & NLA_F_NESTED)) { 1336 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing"); 1337 return -EINVAL; 1338 } 1339 1340 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, 1341 NL_VALIDATE_STRICT, extack); 1342 } 1343 1344 /** 1345 * nla_parse_nested_deprecated - parse nested attributes 1346 * @tb: destination array with maxtype+1 elements 1347 * @maxtype: maximum attribute type to be expected 1348 * @nla: attribute containing the nested attributes 1349 * @policy: validation policy 1350 * @extack: extended ACK report struct 1351 * 1352 * See nla_parse_deprecated() 1353 */ 1354 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype, 1355 const struct nlattr *nla, 1356 const struct nla_policy *policy, 1357 struct netlink_ext_ack *extack) 1358 { 1359 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, 1360 NL_VALIDATE_LIBERAL, extack); 1361 } 1362 1363 /** 1364 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 1365 * @skb: socket buffer to add attribute to 1366 * @attrtype: attribute type 1367 * @value: numeric value 1368 */ 1369 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 1370 { 1371 /* temporary variables to work around GCC PR81715 with asan-stack=1 */ 1372 u8 tmp = value; 1373 1374 return nla_put(skb, attrtype, sizeof(u8), &tmp); 1375 } 1376 1377 /** 1378 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer 1379 * @skb: socket buffer to add attribute to 1380 * @attrtype: attribute type 1381 * @value: numeric value 1382 */ 1383 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) 1384 { 1385 u16 tmp = value; 1386 1387 return nla_put(skb, attrtype, sizeof(u16), &tmp); 1388 } 1389 1390 /** 1391 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer 1392 * @skb: socket buffer to add attribute to 1393 * @attrtype: attribute type 1394 * @value: numeric value 1395 */ 1396 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value) 1397 { 1398 __be16 tmp = value; 1399 1400 return nla_put(skb, attrtype, sizeof(__be16), &tmp); 1401 } 1402 1403 /** 1404 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer 1405 * @skb: socket buffer to add attribute to 1406 * @attrtype: attribute type 1407 * @value: numeric value 1408 */ 1409 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value) 1410 { 1411 __be16 tmp = value; 1412 1413 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 1414 } 1415 1416 /** 1417 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer 1418 * @skb: socket buffer to add attribute to 1419 * @attrtype: attribute type 1420 * @value: numeric value 1421 */ 1422 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value) 1423 { 1424 __le16 tmp = value; 1425 1426 return nla_put(skb, attrtype, sizeof(__le16), &tmp); 1427 } 1428 1429 /** 1430 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 1431 * @skb: socket buffer to add attribute to 1432 * @attrtype: attribute type 1433 * @value: numeric value 1434 */ 1435 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 1436 { 1437 u32 tmp = value; 1438 1439 return nla_put(skb, attrtype, sizeof(u32), &tmp); 1440 } 1441 1442 /** 1443 * nla_put_uint - Add a variable-size unsigned int to a socket buffer 1444 * @skb: socket buffer to add attribute to 1445 * @attrtype: attribute type 1446 * @value: numeric value 1447 */ 1448 static inline int nla_put_uint(struct sk_buff *skb, int attrtype, u64 value) 1449 { 1450 u64 tmp64 = value; 1451 u32 tmp32 = value; 1452 1453 if (tmp64 == tmp32) 1454 return nla_put_u32(skb, attrtype, tmp32); 1455 return nla_put(skb, attrtype, sizeof(u64), &tmp64); 1456 } 1457 1458 /** 1459 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer 1460 * @skb: socket buffer to add attribute to 1461 * @attrtype: attribute type 1462 * @value: numeric value 1463 */ 1464 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value) 1465 { 1466 __be32 tmp = value; 1467 1468 return nla_put(skb, attrtype, sizeof(__be32), &tmp); 1469 } 1470 1471 /** 1472 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer 1473 * @skb: socket buffer to add attribute to 1474 * @attrtype: attribute type 1475 * @value: numeric value 1476 */ 1477 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value) 1478 { 1479 __be32 tmp = value; 1480 1481 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 1482 } 1483 1484 /** 1485 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer 1486 * @skb: socket buffer to add attribute to 1487 * @attrtype: attribute type 1488 * @value: numeric value 1489 */ 1490 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value) 1491 { 1492 __le32 tmp = value; 1493 1494 return nla_put(skb, attrtype, sizeof(__le32), &tmp); 1495 } 1496 1497 /** 1498 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it 1499 * @skb: socket buffer to add attribute to 1500 * @attrtype: attribute type 1501 * @value: numeric value 1502 * @padattr: attribute type for the padding 1503 */ 1504 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype, 1505 u64 value, int padattr) 1506 { 1507 u64 tmp = value; 1508 1509 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1510 } 1511 1512 /** 1513 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it 1514 * @skb: socket buffer to add attribute to 1515 * @attrtype: attribute type 1516 * @value: numeric value 1517 * @padattr: attribute type for the padding 1518 */ 1519 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value, 1520 int padattr) 1521 { 1522 __be64 tmp = value; 1523 1524 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr); 1525 } 1526 1527 /** 1528 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it 1529 * @skb: socket buffer to add attribute to 1530 * @attrtype: attribute type 1531 * @value: numeric value 1532 * @padattr: attribute type for the padding 1533 */ 1534 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value, 1535 int padattr) 1536 { 1537 __be64 tmp = value; 1538 1539 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp, 1540 padattr); 1541 } 1542 1543 /** 1544 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it 1545 * @skb: socket buffer to add attribute to 1546 * @attrtype: attribute type 1547 * @value: numeric value 1548 * @padattr: attribute type for the padding 1549 */ 1550 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value, 1551 int padattr) 1552 { 1553 __le64 tmp = value; 1554 1555 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr); 1556 } 1557 1558 /** 1559 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer 1560 * @skb: socket buffer to add attribute to 1561 * @attrtype: attribute type 1562 * @value: numeric value 1563 */ 1564 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value) 1565 { 1566 s8 tmp = value; 1567 1568 return nla_put(skb, attrtype, sizeof(s8), &tmp); 1569 } 1570 1571 /** 1572 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer 1573 * @skb: socket buffer to add attribute to 1574 * @attrtype: attribute type 1575 * @value: numeric value 1576 */ 1577 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value) 1578 { 1579 s16 tmp = value; 1580 1581 return nla_put(skb, attrtype, sizeof(s16), &tmp); 1582 } 1583 1584 /** 1585 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer 1586 * @skb: socket buffer to add attribute to 1587 * @attrtype: attribute type 1588 * @value: numeric value 1589 */ 1590 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value) 1591 { 1592 s32 tmp = value; 1593 1594 return nla_put(skb, attrtype, sizeof(s32), &tmp); 1595 } 1596 1597 /** 1598 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it 1599 * @skb: socket buffer to add attribute to 1600 * @attrtype: attribute type 1601 * @value: numeric value 1602 * @padattr: attribute type for the padding 1603 */ 1604 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value, 1605 int padattr) 1606 { 1607 s64 tmp = value; 1608 1609 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr); 1610 } 1611 1612 /** 1613 * nla_put_sint - Add a variable-size signed int to a socket buffer 1614 * @skb: socket buffer to add attribute to 1615 * @attrtype: attribute type 1616 * @value: numeric value 1617 */ 1618 static inline int nla_put_sint(struct sk_buff *skb, int attrtype, s64 value) 1619 { 1620 s64 tmp64 = value; 1621 s32 tmp32 = value; 1622 1623 if (tmp64 == tmp32) 1624 return nla_put_s32(skb, attrtype, tmp32); 1625 return nla_put(skb, attrtype, sizeof(s64), &tmp64); 1626 } 1627 1628 /** 1629 * nla_put_string - Add a string netlink attribute to a socket buffer 1630 * @skb: socket buffer to add attribute to 1631 * @attrtype: attribute type 1632 * @str: NUL terminated string 1633 */ 1634 static inline int nla_put_string(struct sk_buff *skb, int attrtype, 1635 const char *str) 1636 { 1637 return nla_put(skb, attrtype, strlen(str) + 1, str); 1638 } 1639 1640 /** 1641 * nla_put_flag - Add a flag netlink attribute to a socket buffer 1642 * @skb: socket buffer to add attribute to 1643 * @attrtype: attribute type 1644 */ 1645 static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 1646 { 1647 return nla_put(skb, attrtype, 0, NULL); 1648 } 1649 1650 /** 1651 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it 1652 * @skb: socket buffer to add attribute to 1653 * @attrtype: attribute type 1654 * @njiffies: number of jiffies to convert to msecs 1655 * @padattr: attribute type for the padding 1656 */ 1657 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 1658 unsigned long njiffies, int padattr) 1659 { 1660 u64 tmp = jiffies_to_msecs(njiffies); 1661 1662 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1663 } 1664 1665 /** 1666 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket 1667 * buffer 1668 * @skb: socket buffer to add attribute to 1669 * @attrtype: attribute type 1670 * @addr: IPv4 address 1671 */ 1672 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype, 1673 __be32 addr) 1674 { 1675 __be32 tmp = addr; 1676 1677 return nla_put_be32(skb, attrtype, tmp); 1678 } 1679 1680 /** 1681 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket 1682 * buffer 1683 * @skb: socket buffer to add attribute to 1684 * @attrtype: attribute type 1685 * @addr: IPv6 address 1686 */ 1687 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype, 1688 const struct in6_addr *addr) 1689 { 1690 return nla_put(skb, attrtype, sizeof(*addr), addr); 1691 } 1692 1693 /** 1694 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer 1695 * @skb: socket buffer to add attribute to 1696 * @attrtype: attribute type 1697 * @value: value carrying bits 1698 * @selector: selector of valid bits 1699 */ 1700 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype, 1701 __u32 value, __u32 selector) 1702 { 1703 struct nla_bitfield32 tmp = { value, selector, }; 1704 1705 return nla_put(skb, attrtype, sizeof(tmp), &tmp); 1706 } 1707 1708 /** 1709 * nla_get_u32 - return payload of u32 attribute 1710 * @nla: u32 netlink attribute 1711 */ 1712 static inline u32 nla_get_u32(const struct nlattr *nla) 1713 { 1714 return *(u32 *) nla_data(nla); 1715 } 1716 1717 /** 1718 * nla_get_u32_default - return payload of u32 attribute or default 1719 * @nla: u32 netlink attribute, may be %NULL 1720 * @defvalue: default value to use if @nla is %NULL 1721 * 1722 * Return: the value of the attribute, or the default value if not present 1723 */ 1724 static inline u32 nla_get_u32_default(const struct nlattr *nla, u32 defvalue) 1725 { 1726 if (!nla) 1727 return defvalue; 1728 return nla_get_u32(nla); 1729 } 1730 1731 /** 1732 * nla_get_be32 - return payload of __be32 attribute 1733 * @nla: __be32 netlink attribute 1734 */ 1735 static inline __be32 nla_get_be32(const struct nlattr *nla) 1736 { 1737 return *(__be32 *) nla_data(nla); 1738 } 1739 1740 /** 1741 * nla_get_be32_default - return payload of be32 attribute or default 1742 * @nla: __be32 netlink attribute, may be %NULL 1743 * @defvalue: default value to use if @nla is %NULL 1744 * 1745 * Return: the value of the attribute, or the default value if not present 1746 */ 1747 static inline __be32 nla_get_be32_default(const struct nlattr *nla, 1748 __be32 defvalue) 1749 { 1750 if (!nla) 1751 return defvalue; 1752 return nla_get_be32(nla); 1753 } 1754 1755 /** 1756 * nla_get_le32 - return payload of __le32 attribute 1757 * @nla: __le32 netlink attribute 1758 */ 1759 static inline __le32 nla_get_le32(const struct nlattr *nla) 1760 { 1761 return *(__le32 *) nla_data(nla); 1762 } 1763 1764 /** 1765 * nla_get_le32_default - return payload of le32 attribute or default 1766 * @nla: __le32 netlink attribute, may be %NULL 1767 * @defvalue: default value to use if @nla is %NULL 1768 * 1769 * Return: the value of the attribute, or the default value if not present 1770 */ 1771 static inline __le32 nla_get_le32_default(const struct nlattr *nla, 1772 __le32 defvalue) 1773 { 1774 if (!nla) 1775 return defvalue; 1776 return nla_get_le32(nla); 1777 } 1778 1779 /** 1780 * nla_get_u16 - return payload of u16 attribute 1781 * @nla: u16 netlink attribute 1782 */ 1783 static inline u16 nla_get_u16(const struct nlattr *nla) 1784 { 1785 return *(u16 *) nla_data(nla); 1786 } 1787 1788 /** 1789 * nla_get_u16_default - return payload of u16 attribute or default 1790 * @nla: u16 netlink attribute, may be %NULL 1791 * @defvalue: default value to use if @nla is %NULL 1792 * 1793 * Return: the value of the attribute, or the default value if not present 1794 */ 1795 static inline u16 nla_get_u16_default(const struct nlattr *nla, u16 defvalue) 1796 { 1797 if (!nla) 1798 return defvalue; 1799 return nla_get_u16(nla); 1800 } 1801 1802 /** 1803 * nla_get_be16 - return payload of __be16 attribute 1804 * @nla: __be16 netlink attribute 1805 */ 1806 static inline __be16 nla_get_be16(const struct nlattr *nla) 1807 { 1808 return *(__be16 *) nla_data(nla); 1809 } 1810 1811 /** 1812 * nla_get_be16_default - return payload of be16 attribute or default 1813 * @nla: __be16 netlink attribute, may be %NULL 1814 * @defvalue: default value to use if @nla is %NULL 1815 * 1816 * Return: the value of the attribute, or the default value if not present 1817 */ 1818 static inline __be16 nla_get_be16_default(const struct nlattr *nla, 1819 __be16 defvalue) 1820 { 1821 if (!nla) 1822 return defvalue; 1823 return nla_get_be16(nla); 1824 } 1825 1826 /** 1827 * nla_get_le16 - return payload of __le16 attribute 1828 * @nla: __le16 netlink attribute 1829 */ 1830 static inline __le16 nla_get_le16(const struct nlattr *nla) 1831 { 1832 return *(__le16 *) nla_data(nla); 1833 } 1834 1835 /** 1836 * nla_get_le16_default - return payload of le16 attribute or default 1837 * @nla: __le16 netlink attribute, may be %NULL 1838 * @defvalue: default value to use if @nla is %NULL 1839 * 1840 * Return: the value of the attribute, or the default value if not present 1841 */ 1842 static inline __le16 nla_get_le16_default(const struct nlattr *nla, 1843 __le16 defvalue) 1844 { 1845 if (!nla) 1846 return defvalue; 1847 return nla_get_le16(nla); 1848 } 1849 1850 /** 1851 * nla_get_u8 - return payload of u8 attribute 1852 * @nla: u8 netlink attribute 1853 */ 1854 static inline u8 nla_get_u8(const struct nlattr *nla) 1855 { 1856 return *(u8 *) nla_data(nla); 1857 } 1858 1859 /** 1860 * nla_get_u8_default - return payload of u8 attribute or default 1861 * @nla: u8 netlink attribute, may be %NULL 1862 * @defvalue: default value to use if @nla is %NULL 1863 * 1864 * Return: the value of the attribute, or the default value if not present 1865 */ 1866 static inline u8 nla_get_u8_default(const struct nlattr *nla, u8 defvalue) 1867 { 1868 if (!nla) 1869 return defvalue; 1870 return nla_get_u8(nla); 1871 } 1872 1873 /** 1874 * nla_get_u64 - return payload of u64 attribute 1875 * @nla: u64 netlink attribute 1876 */ 1877 static inline u64 nla_get_u64(const struct nlattr *nla) 1878 { 1879 u64 tmp; 1880 1881 nla_memcpy(&tmp, nla, sizeof(tmp)); 1882 1883 return tmp; 1884 } 1885 1886 /** 1887 * nla_get_u64_default - return payload of u64 attribute or default 1888 * @nla: u64 netlink attribute, may be %NULL 1889 * @defvalue: default value to use if @nla is %NULL 1890 * 1891 * Return: the value of the attribute, or the default value if not present 1892 */ 1893 static inline u64 nla_get_u64_default(const struct nlattr *nla, u64 defvalue) 1894 { 1895 if (!nla) 1896 return defvalue; 1897 return nla_get_u64(nla); 1898 } 1899 1900 /** 1901 * nla_get_uint - return payload of uint attribute 1902 * @nla: uint netlink attribute 1903 */ 1904 static inline u64 nla_get_uint(const struct nlattr *nla) 1905 { 1906 if (nla_len(nla) == sizeof(u32)) 1907 return nla_get_u32(nla); 1908 return nla_get_u64(nla); 1909 } 1910 1911 /** 1912 * nla_get_uint_default - return payload of uint attribute or default 1913 * @nla: uint netlink attribute, may be %NULL 1914 * @defvalue: default value to use if @nla is %NULL 1915 * 1916 * Return: the value of the attribute, or the default value if not present 1917 */ 1918 static inline u64 nla_get_uint_default(const struct nlattr *nla, u64 defvalue) 1919 { 1920 if (!nla) 1921 return defvalue; 1922 return nla_get_uint(nla); 1923 } 1924 1925 /** 1926 * nla_get_be64 - return payload of __be64 attribute 1927 * @nla: __be64 netlink attribute 1928 */ 1929 static inline __be64 nla_get_be64(const struct nlattr *nla) 1930 { 1931 __be64 tmp; 1932 1933 nla_memcpy(&tmp, nla, sizeof(tmp)); 1934 1935 return tmp; 1936 } 1937 1938 /** 1939 * nla_get_be64_default - return payload of be64 attribute or default 1940 * @nla: __be64 netlink attribute, may be %NULL 1941 * @defvalue: default value to use if @nla is %NULL 1942 * 1943 * Return: the value of the attribute, or the default value if not present 1944 */ 1945 static inline __be64 nla_get_be64_default(const struct nlattr *nla, 1946 __be64 defvalue) 1947 { 1948 if (!nla) 1949 return defvalue; 1950 return nla_get_be64(nla); 1951 } 1952 1953 /** 1954 * nla_get_le64 - return payload of __le64 attribute 1955 * @nla: __le64 netlink attribute 1956 */ 1957 static inline __le64 nla_get_le64(const struct nlattr *nla) 1958 { 1959 return *(__le64 *) nla_data(nla); 1960 } 1961 1962 /** 1963 * nla_get_le64_default - return payload of le64 attribute or default 1964 * @nla: __le64 netlink attribute, may be %NULL 1965 * @defvalue: default value to use if @nla is %NULL 1966 * 1967 * Return: the value of the attribute, or the default value if not present 1968 */ 1969 static inline __le64 nla_get_le64_default(const struct nlattr *nla, 1970 __le64 defvalue) 1971 { 1972 if (!nla) 1973 return defvalue; 1974 return nla_get_le64(nla); 1975 } 1976 1977 /** 1978 * nla_get_s32 - return payload of s32 attribute 1979 * @nla: s32 netlink attribute 1980 */ 1981 static inline s32 nla_get_s32(const struct nlattr *nla) 1982 { 1983 return *(s32 *) nla_data(nla); 1984 } 1985 1986 /** 1987 * nla_get_s32_default - return payload of s32 attribute or default 1988 * @nla: s32 netlink attribute, may be %NULL 1989 * @defvalue: default value to use if @nla is %NULL 1990 * 1991 * Return: the value of the attribute, or the default value if not present 1992 */ 1993 static inline s32 nla_get_s32_default(const struct nlattr *nla, s32 defvalue) 1994 { 1995 if (!nla) 1996 return defvalue; 1997 return nla_get_s32(nla); 1998 } 1999 2000 /** 2001 * nla_get_s16 - return payload of s16 attribute 2002 * @nla: s16 netlink attribute 2003 */ 2004 static inline s16 nla_get_s16(const struct nlattr *nla) 2005 { 2006 return *(s16 *) nla_data(nla); 2007 } 2008 2009 /** 2010 * nla_get_s16_default - return payload of s16 attribute or default 2011 * @nla: s16 netlink attribute, may be %NULL 2012 * @defvalue: default value to use if @nla is %NULL 2013 * 2014 * Return: the value of the attribute, or the default value if not present 2015 */ 2016 static inline s16 nla_get_s16_default(const struct nlattr *nla, s16 defvalue) 2017 { 2018 if (!nla) 2019 return defvalue; 2020 return nla_get_s16(nla); 2021 } 2022 2023 /** 2024 * nla_get_s8 - return payload of s8 attribute 2025 * @nla: s8 netlink attribute 2026 */ 2027 static inline s8 nla_get_s8(const struct nlattr *nla) 2028 { 2029 return *(s8 *) nla_data(nla); 2030 } 2031 2032 /** 2033 * nla_get_s8_default - return payload of s8 attribute or default 2034 * @nla: s8 netlink attribute, may be %NULL 2035 * @defvalue: default value to use if @nla is %NULL 2036 * 2037 * Return: the value of the attribute, or the default value if not present 2038 */ 2039 static inline s8 nla_get_s8_default(const struct nlattr *nla, s8 defvalue) 2040 { 2041 if (!nla) 2042 return defvalue; 2043 return nla_get_s8(nla); 2044 } 2045 2046 /** 2047 * nla_get_s64 - return payload of s64 attribute 2048 * @nla: s64 netlink attribute 2049 */ 2050 static inline s64 nla_get_s64(const struct nlattr *nla) 2051 { 2052 s64 tmp; 2053 2054 nla_memcpy(&tmp, nla, sizeof(tmp)); 2055 2056 return tmp; 2057 } 2058 2059 /** 2060 * nla_get_s64_default - return payload of s64 attribute or default 2061 * @nla: s64 netlink attribute, may be %NULL 2062 * @defvalue: default value to use if @nla is %NULL 2063 * 2064 * Return: the value of the attribute, or the default value if not present 2065 */ 2066 static inline s64 nla_get_s64_default(const struct nlattr *nla, s64 defvalue) 2067 { 2068 if (!nla) 2069 return defvalue; 2070 return nla_get_s64(nla); 2071 } 2072 2073 /** 2074 * nla_get_sint - return payload of uint attribute 2075 * @nla: uint netlink attribute 2076 */ 2077 static inline s64 nla_get_sint(const struct nlattr *nla) 2078 { 2079 if (nla_len(nla) == sizeof(s32)) 2080 return nla_get_s32(nla); 2081 return nla_get_s64(nla); 2082 } 2083 2084 /** 2085 * nla_get_sint_default - return payload of sint attribute or default 2086 * @nla: sint netlink attribute, may be %NULL 2087 * @defvalue: default value to use if @nla is %NULL 2088 * 2089 * Return: the value of the attribute, or the default value if not present 2090 */ 2091 static inline s64 nla_get_sint_default(const struct nlattr *nla, s64 defvalue) 2092 { 2093 if (!nla) 2094 return defvalue; 2095 return nla_get_sint(nla); 2096 } 2097 2098 /** 2099 * nla_get_flag - return payload of flag attribute 2100 * @nla: flag netlink attribute 2101 */ 2102 static inline int nla_get_flag(const struct nlattr *nla) 2103 { 2104 return !!nla; 2105 } 2106 2107 /** 2108 * nla_get_msecs - return payload of msecs attribute 2109 * @nla: msecs netlink attribute 2110 * 2111 * Returns: the number of milliseconds in jiffies. 2112 */ 2113 static inline unsigned long nla_get_msecs(const struct nlattr *nla) 2114 { 2115 u64 msecs = nla_get_u64(nla); 2116 2117 return msecs_to_jiffies((unsigned long) msecs); 2118 } 2119 2120 /** 2121 * nla_get_msecs_default - return payload of msecs attribute or default 2122 * @nla: msecs netlink attribute, may be %NULL 2123 * @defvalue: default value to use if @nla is %NULL 2124 * 2125 * Return: the value of the attribute, or the default value if not present 2126 */ 2127 static inline unsigned long nla_get_msecs_default(const struct nlattr *nla, 2128 unsigned long defvalue) 2129 { 2130 if (!nla) 2131 return defvalue; 2132 return nla_get_msecs(nla); 2133 } 2134 2135 /** 2136 * nla_get_in_addr - return payload of IPv4 address attribute 2137 * @nla: IPv4 address netlink attribute 2138 */ 2139 static inline __be32 nla_get_in_addr(const struct nlattr *nla) 2140 { 2141 return *(__be32 *) nla_data(nla); 2142 } 2143 2144 /** 2145 * nla_get_in_addr_default - return payload of be32 attribute or default 2146 * @nla: IPv4 address netlink attribute, may be %NULL 2147 * @defvalue: default value to use if @nla is %NULL 2148 * 2149 * Return: the value of the attribute, or the default value if not present 2150 */ 2151 static inline __be32 nla_get_in_addr_default(const struct nlattr *nla, 2152 __be32 defvalue) 2153 { 2154 if (!nla) 2155 return defvalue; 2156 return nla_get_in_addr(nla); 2157 } 2158 2159 /** 2160 * nla_get_in6_addr - return payload of IPv6 address attribute 2161 * @nla: IPv6 address netlink attribute 2162 */ 2163 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla) 2164 { 2165 struct in6_addr tmp; 2166 2167 nla_memcpy(&tmp, nla, sizeof(tmp)); 2168 return tmp; 2169 } 2170 2171 /** 2172 * nla_get_bitfield32 - return payload of 32 bitfield attribute 2173 * @nla: nla_bitfield32 attribute 2174 */ 2175 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla) 2176 { 2177 struct nla_bitfield32 tmp; 2178 2179 nla_memcpy(&tmp, nla, sizeof(tmp)); 2180 return tmp; 2181 } 2182 2183 /** 2184 * nla_memdup - duplicate attribute memory (kmemdup) 2185 * @src: netlink attribute to duplicate from 2186 * @gfp: GFP mask 2187 */ 2188 static inline void *nla_memdup_noprof(const struct nlattr *src, gfp_t gfp) 2189 { 2190 return kmemdup_noprof(nla_data(src), nla_len(src), gfp); 2191 } 2192 #define nla_memdup(...) alloc_hooks(nla_memdup_noprof(__VA_ARGS__)) 2193 2194 /** 2195 * nla_nest_start_noflag - Start a new level of nested attributes 2196 * @skb: socket buffer to add attributes to 2197 * @attrtype: attribute type of container 2198 * 2199 * This function exists for backward compatibility to use in APIs which never 2200 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use 2201 * nla_nest_start() which sets the flag. 2202 * 2203 * Returns: the container attribute or NULL on error 2204 */ 2205 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb, 2206 int attrtype) 2207 { 2208 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 2209 2210 if (nla_put(skb, attrtype, 0, NULL) < 0) 2211 return NULL; 2212 2213 return start; 2214 } 2215 2216 /** 2217 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED 2218 * @skb: socket buffer to add attributes to 2219 * @attrtype: attribute type of container 2220 * 2221 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED 2222 * flag. This is the preferred function to use in new code. 2223 * 2224 * Returns: the container attribute or NULL on error 2225 */ 2226 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 2227 { 2228 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED); 2229 } 2230 2231 /** 2232 * nla_nest_end - Finalize nesting of attributes 2233 * @skb: socket buffer the attributes are stored in 2234 * @start: container attribute 2235 * 2236 * Corrects the container attribute header to include the all 2237 * appended attributes. 2238 * 2239 * Returns: the total data length of the skb. 2240 */ 2241 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 2242 { 2243 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 2244 return skb->len; 2245 } 2246 2247 /** 2248 * nla_nest_cancel - Cancel nesting of attributes 2249 * @skb: socket buffer the message is stored in 2250 * @start: container attribute 2251 * 2252 * Removes the container attribute and including all nested 2253 * attributes. Returns -EMSGSIZE 2254 */ 2255 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 2256 { 2257 nlmsg_trim(skb, start); 2258 } 2259 2260 /** 2261 * nla_put_empty_nest - Create an empty nest 2262 * @skb: socket buffer the message is stored in 2263 * @attrtype: attribute type of the container 2264 * 2265 * This function is a helper for creating empty nests. 2266 * 2267 * Returns: 0 when successful or -EMSGSIZE on failure. 2268 */ 2269 static inline int nla_put_empty_nest(struct sk_buff *skb, int attrtype) 2270 { 2271 return nla_nest_start(skb, attrtype) ? 0 : -EMSGSIZE; 2272 } 2273 2274 /** 2275 * __nla_validate_nested - Validate a stream of nested attributes 2276 * @start: container attribute 2277 * @maxtype: maximum attribute type to be expected 2278 * @policy: validation policy 2279 * @validate: validation strictness 2280 * @extack: extended ACK report struct 2281 * 2282 * Validates all attributes in the nested attribute stream against the 2283 * specified policy. Attributes with a type exceeding maxtype will be 2284 * ignored. See documentation of struct nla_policy for more details. 2285 * 2286 * Returns: 0 on success or a negative error code. 2287 */ 2288 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype, 2289 const struct nla_policy *policy, 2290 unsigned int validate, 2291 struct netlink_ext_ack *extack) 2292 { 2293 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy, 2294 validate, extack); 2295 } 2296 2297 static inline int 2298 nla_validate_nested(const struct nlattr *start, int maxtype, 2299 const struct nla_policy *policy, 2300 struct netlink_ext_ack *extack) 2301 { 2302 return __nla_validate_nested(start, maxtype, policy, 2303 NL_VALIDATE_STRICT, extack); 2304 } 2305 2306 static inline int 2307 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype, 2308 const struct nla_policy *policy, 2309 struct netlink_ext_ack *extack) 2310 { 2311 return __nla_validate_nested(start, maxtype, policy, 2312 NL_VALIDATE_LIBERAL, extack); 2313 } 2314 2315 /** 2316 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute 2317 * @skb: socket buffer the message is stored in 2318 * 2319 * Return: true if padding is needed to align the next attribute (nla_data()) to 2320 * a 64-bit aligned area. 2321 */ 2322 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb) 2323 { 2324 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2325 /* The nlattr header is 4 bytes in size, that's why we test 2326 * if the skb->data _is_ aligned. A NOP attribute, plus 2327 * nlattr header for next attribute, will make nla_data() 2328 * 8-byte aligned. 2329 */ 2330 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8)) 2331 return true; 2332 #endif 2333 return false; 2334 } 2335 2336 /** 2337 * nla_align_64bit - 64-bit align the nla_data() of next attribute 2338 * @skb: socket buffer the message is stored in 2339 * @padattr: attribute type for the padding 2340 * 2341 * Conditionally emit a padding netlink attribute in order to make 2342 * the next attribute we emit have a 64-bit aligned nla_data() area. 2343 * This will only be done in architectures which do not have 2344 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined. 2345 * 2346 * Returns: zero on success or a negative error code. 2347 */ 2348 static inline int nla_align_64bit(struct sk_buff *skb, int padattr) 2349 { 2350 if (nla_need_padding_for_64bit(skb) && 2351 !nla_reserve(skb, padattr, 0)) 2352 return -EMSGSIZE; 2353 2354 return 0; 2355 } 2356 2357 /** 2358 * nla_total_size_64bit - total length of attribute including padding 2359 * @payload: length of payload 2360 */ 2361 static inline int nla_total_size_64bit(int payload) 2362 { 2363 return NLA_ALIGN(nla_attr_size(payload)) 2364 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2365 + NLA_ALIGN(nla_attr_size(0)) 2366 #endif 2367 ; 2368 } 2369 2370 /** 2371 * nla_for_each_attr - iterate over a stream of attributes 2372 * @pos: loop counter, set to current attribute 2373 * @head: head of attribute stream 2374 * @len: length of attribute stream 2375 * @rem: initialized to len, holds bytes currently remaining in stream 2376 */ 2377 #define nla_for_each_attr(pos, head, len, rem) \ 2378 for (pos = head, rem = len; \ 2379 nla_ok(pos, rem); \ 2380 pos = nla_next(pos, &(rem))) 2381 2382 /** 2383 * nla_for_each_attr_type - iterate over a stream of attributes 2384 * @pos: loop counter, set to current attribute 2385 * @type: required attribute type for @pos 2386 * @head: head of attribute stream 2387 * @len: length of attribute stream 2388 * @rem: initialized to len, holds bytes currently remaining in stream 2389 */ 2390 #define nla_for_each_attr_type(pos, type, head, len, rem) \ 2391 nla_for_each_attr(pos, head, len, rem) \ 2392 if (nla_type(pos) == type) 2393 2394 /** 2395 * nla_for_each_nested - iterate over nested attributes 2396 * @pos: loop counter, set to current attribute 2397 * @nla: attribute containing the nested attributes 2398 * @rem: initialized to len, holds bytes currently remaining in stream 2399 */ 2400 #define nla_for_each_nested(pos, nla, rem) \ 2401 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 2402 2403 /** 2404 * nla_for_each_nested_type - iterate over nested attributes 2405 * @pos: loop counter, set to current attribute 2406 * @type: required attribute type for @pos 2407 * @nla: attribute containing the nested attributes 2408 * @rem: initialized to len, holds bytes currently remaining in stream 2409 */ 2410 #define nla_for_each_nested_type(pos, type, nla, rem) \ 2411 nla_for_each_nested(pos, nla, rem) \ 2412 if (nla_type(pos) == type) 2413 2414 /** 2415 * nla_is_last - Test if attribute is last in stream 2416 * @nla: attribute to test 2417 * @rem: bytes remaining in stream 2418 */ 2419 static inline bool nla_is_last(const struct nlattr *nla, int rem) 2420 { 2421 return nla->nla_len == rem; 2422 } 2423 2424 void nla_get_range_unsigned(const struct nla_policy *pt, 2425 struct netlink_range_validation *range); 2426 void nla_get_range_signed(const struct nla_policy *pt, 2427 struct netlink_range_validation_signed *range); 2428 2429 struct netlink_policy_dump_state; 2430 2431 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate, 2432 const struct nla_policy *policy, 2433 unsigned int maxtype); 2434 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state, 2435 const struct nla_policy *policy, 2436 unsigned int maxtype); 2437 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state); 2438 int netlink_policy_dump_write(struct sk_buff *skb, 2439 struct netlink_policy_dump_state *state); 2440 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt); 2441 int netlink_policy_dump_write_attr(struct sk_buff *skb, 2442 const struct nla_policy *pt, 2443 int nestattr); 2444 void netlink_policy_dump_free(struct netlink_policy_dump_state *state); 2445 2446 #endif 2447