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