1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __NET_NETLINK_H 3 #define __NET_NETLINK_H 4 5 #include <linux/types.h> 6 #include <linux/netlink.h> 7 #include <linux/jiffies.h> 8 #include <linux/in6.h> 9 10 /* ======================================================================== 11 * Netlink Messages and Attributes Interface (As Seen On TV) 12 * ------------------------------------------------------------------------ 13 * Messages Interface 14 * ------------------------------------------------------------------------ 15 * 16 * Message Format: 17 * <--- nlmsg_total_size(payload) ---> 18 * <-- nlmsg_msg_size(payload) -> 19 * +----------+- - -+-------------+- - -+-------- - - 20 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr 21 * +----------+- - -+-------------+- - -+-------- - - 22 * nlmsg_data(nlh)---^ ^ 23 * nlmsg_next(nlh)-----------------------+ 24 * 25 * Payload Format: 26 * <---------------------- nlmsg_len(nlh) ---------------------> 27 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) -> 28 * +----------------------+- - -+--------------------------------+ 29 * | Family Header | Pad | Attributes | 30 * +----------------------+- - -+--------------------------------+ 31 * nlmsg_attrdata(nlh, hdrlen)---^ 32 * 33 * Data Structures: 34 * struct nlmsghdr netlink message header 35 * 36 * Message Construction: 37 * nlmsg_new() create a new netlink message 38 * nlmsg_put() add a netlink message to an skb 39 * nlmsg_put_answer() callback based nlmsg_put() 40 * nlmsg_end() finalize netlink message 41 * nlmsg_get_pos() return current position in message 42 * nlmsg_trim() trim part of message 43 * nlmsg_cancel() cancel message construction 44 * nlmsg_free() free a netlink message 45 * 46 * Message Sending: 47 * nlmsg_multicast() multicast message to several groups 48 * nlmsg_unicast() unicast a message to a single socket 49 * nlmsg_notify() send notification message 50 * 51 * Message Length Calculations: 52 * nlmsg_msg_size(payload) length of message w/o padding 53 * nlmsg_total_size(payload) length of message w/ padding 54 * nlmsg_padlen(payload) length of padding at tail 55 * 56 * Message Payload Access: 57 * nlmsg_data(nlh) head of message payload 58 * nlmsg_len(nlh) length of message payload 59 * nlmsg_attrdata(nlh, hdrlen) head of attributes data 60 * nlmsg_attrlen(nlh, hdrlen) length of attributes data 61 * 62 * Message Parsing: 63 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes? 64 * nlmsg_next(nlh, remaining) get next netlink message 65 * nlmsg_parse() parse attributes of a message 66 * nlmsg_find_attr() find an attribute in a message 67 * nlmsg_for_each_msg() loop over all messages 68 * nlmsg_validate() validate netlink message incl. attrs 69 * nlmsg_for_each_attr() loop over all attributes 70 * 71 * Misc: 72 * nlmsg_report() report back to application? 73 * 74 * ------------------------------------------------------------------------ 75 * Attributes Interface 76 * ------------------------------------------------------------------------ 77 * 78 * Attribute Format: 79 * <------- nla_total_size(payload) -------> 80 * <---- nla_attr_size(payload) -----> 81 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 82 * | Header | Pad | Payload | Pad | Header 83 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 84 * <- nla_len(nla) -> ^ 85 * nla_data(nla)----^ | 86 * nla_next(nla)-----------------------------' 87 * 88 * Data Structures: 89 * struct nlattr netlink attribute header 90 * 91 * Attribute Construction: 92 * nla_reserve(skb, type, len) reserve room for an attribute 93 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr 94 * nla_put(skb, type, len, data) add attribute to skb 95 * nla_put_nohdr(skb, len, data) add attribute w/o hdr 96 * nla_append(skb, len, data) append data to skb 97 * 98 * Attribute Construction for Basic Types: 99 * nla_put_u8(skb, type, value) add u8 attribute to skb 100 * nla_put_u16(skb, type, value) add u16 attribute to skb 101 * nla_put_u32(skb, type, value) add u32 attribute to skb 102 * nla_put_u64_64bit(skb, type, 103 * value, padattr) add u64 attribute to skb 104 * nla_put_s8(skb, type, value) add s8 attribute to skb 105 * nla_put_s16(skb, type, value) add s16 attribute to skb 106 * nla_put_s32(skb, type, value) add s32 attribute to skb 107 * nla_put_s64(skb, type, value, 108 * padattr) add s64 attribute to skb 109 * nla_put_string(skb, type, str) add string attribute to skb 110 * nla_put_flag(skb, type) add flag attribute to skb 111 * nla_put_msecs(skb, type, jiffies, 112 * padattr) add msecs attribute to skb 113 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb 114 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb 115 * 116 * Nested Attributes Construction: 117 * nla_nest_start(skb, type) start a nested attribute 118 * nla_nest_end(skb, nla) finalize a nested attribute 119 * nla_nest_cancel(skb, nla) cancel nested attribute construction 120 * 121 * Attribute Length Calculations: 122 * nla_attr_size(payload) length of attribute w/o padding 123 * nla_total_size(payload) length of attribute w/ padding 124 * nla_padlen(payload) length of padding 125 * 126 * Attribute Payload Access: 127 * nla_data(nla) head of attribute payload 128 * nla_len(nla) length of attribute payload 129 * 130 * Attribute Payload Access for Basic Types: 131 * nla_get_uint(nla) get payload for a uint attribute 132 * nla_get_sint(nla) get payload for a sint attribute 133 * nla_get_u8(nla) get payload for a u8 attribute 134 * nla_get_u16(nla) get payload for a u16 attribute 135 * nla_get_u32(nla) get payload for a u32 attribute 136 * nla_get_u64(nla) get payload for a u64 attribute 137 * nla_get_s8(nla) get payload for a s8 attribute 138 * nla_get_s16(nla) get payload for a s16 attribute 139 * nla_get_s32(nla) get payload for a s32 attribute 140 * nla_get_s64(nla) get payload for a s64 attribute 141 * nla_get_flag(nla) return 1 if flag is true 142 * nla_get_msecs(nla) get payload for a msecs attribute 143 * 144 * Attribute Misc: 145 * nla_memcpy(dest, nla, count) copy attribute into memory 146 * nla_memcmp(nla, data, size) compare attribute with memory area 147 * nla_strscpy(dst, nla, size) copy attribute to a sized string 148 * nla_strcmp(nla, str) compare attribute with string 149 * 150 * Attribute Parsing: 151 * nla_ok(nla, remaining) does nla fit into remaining bytes? 152 * nla_next(nla, remaining) get next netlink attribute 153 * nla_validate() validate a stream of attributes 154 * nla_validate_nested() validate a stream of nested attributes 155 * nla_find() find attribute in stream of attributes 156 * nla_find_nested() find attribute in nested attributes 157 * nla_parse() parse and validate stream of attrs 158 * nla_parse_nested() parse nested attributes 159 * nla_for_each_attr() loop over all attributes 160 * nla_for_each_nested() loop over the nested attributes 161 *========================================================================= 162 */ 163 164 /** 165 * Standard attribute types to specify validation policy 166 */ 167 enum { 168 NLA_UNSPEC, 169 NLA_U8, 170 NLA_U16, 171 NLA_U32, 172 NLA_U64, 173 NLA_STRING, 174 NLA_FLAG, 175 NLA_MSECS, 176 NLA_NESTED, 177 NLA_NESTED_ARRAY, 178 NLA_NUL_STRING, 179 NLA_BINARY, 180 NLA_S8, 181 NLA_S16, 182 NLA_S32, 183 NLA_S64, 184 NLA_BITFIELD32, 185 NLA_REJECT, 186 NLA_BE16, 187 NLA_BE32, 188 NLA_SINT, 189 NLA_UINT, 190 __NLA_TYPE_MAX, 191 }; 192 193 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) 194 195 struct netlink_range_validation { 196 u64 min, max; 197 }; 198 199 struct netlink_range_validation_signed { 200 s64 min, max; 201 }; 202 203 enum nla_policy_validation { 204 NLA_VALIDATE_NONE, 205 NLA_VALIDATE_RANGE, 206 NLA_VALIDATE_RANGE_WARN_TOO_LONG, 207 NLA_VALIDATE_MIN, 208 NLA_VALIDATE_MAX, 209 NLA_VALIDATE_MASK, 210 NLA_VALIDATE_RANGE_PTR, 211 NLA_VALIDATE_FUNCTION, 212 }; 213 214 /** 215 * struct nla_policy - attribute validation policy 216 * @type: Type of attribute or NLA_UNSPEC 217 * @validation_type: type of attribute validation done in addition to 218 * type-specific validation (e.g. range, function call), see 219 * &enum nla_policy_validation 220 * @len: Type specific length of payload 221 * 222 * Policies are defined as arrays of this struct, the array must be 223 * accessible by attribute type up to the highest identifier to be expected. 224 * 225 * Meaning of `len' field: 226 * NLA_STRING Maximum length of string 227 * NLA_NUL_STRING Maximum length of string (excluding NUL) 228 * NLA_FLAG Unused 229 * NLA_BINARY Maximum length of attribute payload 230 * (but see also below with the validation type) 231 * NLA_NESTED, 232 * NLA_NESTED_ARRAY Length verification is done by checking len of 233 * nested header (or empty); len field is used if 234 * nested_policy is also used, for the max attr 235 * number in the nested policy. 236 * NLA_SINT, NLA_UINT, 237 * NLA_U8, NLA_U16, 238 * NLA_U32, NLA_U64, 239 * NLA_S8, NLA_S16, 240 * NLA_S32, NLA_S64, 241 * NLA_BE16, NLA_BE32, 242 * NLA_MSECS Leaving the length field zero will verify the 243 * given type fits, using it verifies minimum length 244 * just like "All other" 245 * NLA_BITFIELD32 Unused 246 * NLA_REJECT Unused 247 * All other Minimum length of attribute payload 248 * 249 * Meaning of validation union: 250 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and 251 * `bitfield32_valid' is the u32 value of valid flags 252 * NLA_REJECT This attribute is always rejected and `reject_message' 253 * may point to a string to report as the error instead 254 * of the generic one in extended ACK. 255 * NLA_NESTED `nested_policy' to a nested policy to validate, must 256 * also set `len' to the max attribute number. Use the 257 * provided NLA_POLICY_NESTED() macro. 258 * Note that nla_parse() will validate, but of course not 259 * parse, the nested sub-policies. 260 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate, 261 * must also set `len' to the max attribute number. Use 262 * the provided NLA_POLICY_NESTED_ARRAY() macro. 263 * The difference to NLA_NESTED is the structure: 264 * NLA_NESTED has the nested attributes directly inside 265 * while an array has the nested attributes at another 266 * level down and the attribute types directly in the 267 * nesting don't matter. 268 * NLA_UINT, 269 * NLA_U8, 270 * NLA_U16, 271 * NLA_U32, 272 * NLA_U64, 273 * NLA_BE16, 274 * NLA_BE32, 275 * NLA_SINT, 276 * NLA_S8, 277 * NLA_S16, 278 * NLA_S32, 279 * NLA_S64 The `min' and `max' fields are used depending on the 280 * validation_type field, if that is min/max/range then 281 * the min, max or both are used (respectively) to check 282 * the value of the integer attribute. 283 * Note that in the interest of code simplicity and 284 * struct size both limits are s16, so you cannot 285 * enforce a range that doesn't fall within the range 286 * of s16 - do that using the NLA_POLICY_FULL_RANGE() 287 * or NLA_POLICY_FULL_RANGE_SIGNED() macros instead. 288 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and 289 * NLA_POLICY_RANGE() macros. 290 * NLA_UINT, 291 * NLA_U8, 292 * NLA_U16, 293 * NLA_U32, 294 * NLA_U64 If the validation_type field instead is set to 295 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer 296 * to a struct netlink_range_validation that indicates 297 * the min/max values. 298 * Use NLA_POLICY_FULL_RANGE(). 299 * NLA_SINT, 300 * NLA_S8, 301 * NLA_S16, 302 * NLA_S32, 303 * NLA_S64 If the validation_type field instead is set to 304 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a 305 * pointer to a struct netlink_range_validation_signed 306 * that indicates the min/max values. 307 * Use NLA_POLICY_FULL_RANGE_SIGNED(). 308 * 309 * NLA_BINARY If the validation type is like the ones for integers 310 * above, then the min/max length (not value like for 311 * integers) of the attribute is enforced. 312 * 313 * All other Unused - but note that it's a union 314 * 315 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN: 316 * NLA_BINARY Validation function called for the attribute. 317 * All other Unused - but note that it's a union 318 * 319 * Example: 320 * 321 * static const u32 myvalidflags = 0xff231023; 322 * 323 * static const struct nla_policy my_policy[ATTR_MAX+1] = { 324 * [ATTR_FOO] = { .type = NLA_U16 }, 325 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, 326 * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)), 327 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags), 328 * }; 329 */ 330 struct nla_policy { 331 u8 type; 332 u8 validation_type; 333 u16 len; 334 union { 335 /** 336 * @strict_start_type: first attribute to validate strictly 337 * 338 * This entry is special, and used for the attribute at index 0 339 * only, and specifies special data about the policy, namely it 340 * specifies the "boundary type" where strict length validation 341 * starts for any attribute types >= this value, also, strict 342 * nesting validation starts here. 343 * 344 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT 345 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to 346 * get the previous pure { .len = xyz } behaviour. The advantage 347 * of this is that types not specified in the policy will be 348 * rejected. 349 * 350 * For completely new families it should be set to 1 so that the 351 * validation is enforced for all attributes. For existing ones 352 * it should be set at least when new attributes are added to 353 * the enum used by the policy, and be set to the new value that 354 * was added to enforce strict validation from thereon. 355 */ 356 u16 strict_start_type; 357 358 /* private: use NLA_POLICY_*() to set */ 359 const u32 bitfield32_valid; 360 const u32 mask; 361 const char *reject_message; 362 const struct nla_policy *nested_policy; 363 const struct netlink_range_validation *range; 364 const struct netlink_range_validation_signed *range_signed; 365 struct { 366 s16 min, max; 367 }; 368 int (*validate)(const struct nlattr *attr, 369 struct netlink_ext_ack *extack); 370 }; 371 }; 372 373 #define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) 374 #define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) 375 376 #define _NLA_POLICY_NESTED(maxattr, policy) \ 377 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr } 378 #define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ 379 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr } 380 #define NLA_POLICY_NESTED(policy) \ 381 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy) 382 #define NLA_POLICY_NESTED_ARRAY(policy) \ 383 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy) 384 #define NLA_POLICY_BITFIELD32(valid) \ 385 { .type = NLA_BITFIELD32, .bitfield32_valid = valid } 386 387 #define __NLA_IS_UINT_TYPE(tp) \ 388 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || \ 389 tp == NLA_U64 || tp == NLA_UINT || \ 390 tp == NLA_BE16 || tp == NLA_BE32) 391 #define __NLA_IS_SINT_TYPE(tp) \ 392 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64 || \ 393 tp == NLA_SINT) 394 395 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition)) 396 #define NLA_ENSURE_UINT_TYPE(tp) \ 397 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp) 398 #define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \ 399 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \ 400 tp == NLA_MSECS || \ 401 tp == NLA_BINARY) + tp) 402 #define NLA_ENSURE_SINT_TYPE(tp) \ 403 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp) 404 #define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \ 405 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \ 406 __NLA_IS_SINT_TYPE(tp) || \ 407 tp == NLA_MSECS || \ 408 tp == NLA_BINARY) + tp) 409 #define NLA_ENSURE_NO_VALIDATION_PTR(tp) \ 410 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \ 411 tp != NLA_REJECT && \ 412 tp != NLA_NESTED && \ 413 tp != NLA_NESTED_ARRAY) + tp) 414 415 #define NLA_POLICY_RANGE(tp, _min, _max) { \ 416 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 417 .validation_type = NLA_VALIDATE_RANGE, \ 418 .min = _min, \ 419 .max = _max \ 420 } 421 422 #define NLA_POLICY_FULL_RANGE(tp, _range) { \ 423 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \ 424 .validation_type = NLA_VALIDATE_RANGE_PTR, \ 425 .range = _range, \ 426 } 427 428 #define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \ 429 .type = NLA_ENSURE_SINT_TYPE(tp), \ 430 .validation_type = NLA_VALIDATE_RANGE_PTR, \ 431 .range_signed = _range, \ 432 } 433 434 #define NLA_POLICY_MIN(tp, _min) { \ 435 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 436 .validation_type = NLA_VALIDATE_MIN, \ 437 .min = _min, \ 438 } 439 440 #define NLA_POLICY_MAX(tp, _max) { \ 441 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 442 .validation_type = NLA_VALIDATE_MAX, \ 443 .max = _max, \ 444 } 445 446 #define NLA_POLICY_MASK(tp, _mask) { \ 447 .type = NLA_ENSURE_UINT_TYPE(tp), \ 448 .validation_type = NLA_VALIDATE_MASK, \ 449 .mask = _mask, \ 450 } 451 452 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \ 453 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \ 454 .validation_type = NLA_VALIDATE_FUNCTION, \ 455 .validate = fn, \ 456 .len = __VA_ARGS__ + 0, \ 457 } 458 459 #define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len) 460 #define NLA_POLICY_EXACT_LEN_WARN(_len) { \ 461 .type = NLA_BINARY, \ 462 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \ 463 .min = _len, \ 464 .max = _len \ 465 } 466 #define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len) 467 468 /** 469 * struct nl_info - netlink source information 470 * @nlh: Netlink message header of original request 471 * @nl_net: Network namespace 472 * @portid: Netlink PORTID of requesting application 473 * @skip_notify: Skip netlink notifications to user space 474 * @skip_notify_kernel: Skip selected in-kernel notifications 475 */ 476 struct nl_info { 477 struct nlmsghdr *nlh; 478 struct net *nl_net; 479 u32 portid; 480 u8 skip_notify:1, 481 skip_notify_kernel:1; 482 }; 483 484 /** 485 * enum netlink_validation - netlink message/attribute validation levels 486 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about 487 * extra data at the end of the message, attributes being longer than 488 * they should be, or unknown attributes being present. 489 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing. 490 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING 491 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict(). 492 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy. 493 * This can safely be set by the kernel when the given policy has no 494 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries 495 * are enforced going forward. 496 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g. 497 * U8, U16, U32 must have exact size, etc.) 498 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY) 499 * and unset for other policies. 500 */ 501 enum netlink_validation { 502 NL_VALIDATE_LIBERAL = 0, 503 NL_VALIDATE_TRAILING = BIT(0), 504 NL_VALIDATE_MAXTYPE = BIT(1), 505 NL_VALIDATE_UNSPEC = BIT(2), 506 NL_VALIDATE_STRICT_ATTRS = BIT(3), 507 NL_VALIDATE_NESTED = BIT(4), 508 }; 509 510 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\ 511 NL_VALIDATE_MAXTYPE) 512 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\ 513 NL_VALIDATE_MAXTYPE |\ 514 NL_VALIDATE_UNSPEC |\ 515 NL_VALIDATE_STRICT_ATTRS |\ 516 NL_VALIDATE_NESTED) 517 518 int netlink_rcv_skb(struct sk_buff *skb, 519 int (*cb)(struct sk_buff *, struct nlmsghdr *, 520 struct netlink_ext_ack *)); 521 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, 522 unsigned int group, int report, gfp_t flags); 523 524 int __nla_validate(const struct nlattr *head, int len, int maxtype, 525 const struct nla_policy *policy, unsigned int validate, 526 struct netlink_ext_ack *extack); 527 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, 528 int len, const struct nla_policy *policy, unsigned int validate, 529 struct netlink_ext_ack *extack); 530 int nla_policy_len(const struct nla_policy *, int); 531 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype); 532 ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize); 533 char *nla_strdup(const struct nlattr *nla, gfp_t flags); 534 int nla_memcpy(void *dest, const struct nlattr *src, int count); 535 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size); 536 int nla_strcmp(const struct nlattr *nla, const char *str); 537 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 538 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, 539 int attrlen, int padattr); 540 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 541 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 542 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, 543 int attrlen, int padattr); 544 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 545 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, 546 const void *data); 547 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 548 const void *data, int padattr); 549 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 550 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); 551 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 552 const void *data, int padattr); 553 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 554 int nla_append(struct sk_buff *skb, int attrlen, const void *data); 555 556 /************************************************************************** 557 * Netlink Messages 558 **************************************************************************/ 559 560 /** 561 * nlmsg_msg_size - length of netlink message not including padding 562 * @payload: length of message payload 563 */ 564 static inline int nlmsg_msg_size(int payload) 565 { 566 return NLMSG_HDRLEN + payload; 567 } 568 569 /** 570 * nlmsg_total_size - length of netlink message including padding 571 * @payload: length of message payload 572 */ 573 static inline int nlmsg_total_size(int payload) 574 { 575 return NLMSG_ALIGN(nlmsg_msg_size(payload)); 576 } 577 578 /** 579 * nlmsg_padlen - length of padding at the message's tail 580 * @payload: length of message payload 581 */ 582 static inline int nlmsg_padlen(int payload) 583 { 584 return nlmsg_total_size(payload) - nlmsg_msg_size(payload); 585 } 586 587 /** 588 * nlmsg_data - head of message payload 589 * @nlh: netlink message header 590 */ 591 static inline void *nlmsg_data(const struct nlmsghdr *nlh) 592 { 593 return (unsigned char *) nlh + NLMSG_HDRLEN; 594 } 595 596 /** 597 * nlmsg_len - length of message payload 598 * @nlh: netlink message header 599 */ 600 static inline int nlmsg_len(const struct nlmsghdr *nlh) 601 { 602 return nlh->nlmsg_len - NLMSG_HDRLEN; 603 } 604 605 /** 606 * nlmsg_attrdata - head of attributes data 607 * @nlh: netlink message header 608 * @hdrlen: length of family specific header 609 */ 610 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 611 int hdrlen) 612 { 613 unsigned char *data = nlmsg_data(nlh); 614 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); 615 } 616 617 /** 618 * nlmsg_attrlen - length of attributes data 619 * @nlh: netlink message header 620 * @hdrlen: length of family specific header 621 */ 622 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) 623 { 624 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); 625 } 626 627 /** 628 * nlmsg_ok - check if the netlink message fits into the remaining bytes 629 * @nlh: netlink message header 630 * @remaining: number of bytes remaining in message stream 631 */ 632 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) 633 { 634 return (remaining >= (int) sizeof(struct nlmsghdr) && 635 nlh->nlmsg_len >= sizeof(struct nlmsghdr) && 636 nlh->nlmsg_len <= remaining); 637 } 638 639 /** 640 * nlmsg_next - next netlink message in message stream 641 * @nlh: netlink message header 642 * @remaining: number of bytes remaining in message stream 643 * 644 * Returns the next netlink message in the message stream and 645 * decrements remaining by the size of the current message. 646 */ 647 static inline struct nlmsghdr * 648 nlmsg_next(const struct nlmsghdr *nlh, int *remaining) 649 { 650 int totlen = NLMSG_ALIGN(nlh->nlmsg_len); 651 652 *remaining -= totlen; 653 654 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); 655 } 656 657 /** 658 * nla_parse - Parse a stream of attributes into a tb buffer 659 * @tb: destination array with maxtype+1 elements 660 * @maxtype: maximum attribute type to be expected 661 * @head: head of attribute stream 662 * @len: length of attribute stream 663 * @policy: validation policy 664 * @extack: extended ACK pointer 665 * 666 * Parses a stream of attributes and stores a pointer to each attribute in 667 * the tb array accessible via the attribute type. Attributes with a type 668 * exceeding maxtype will be rejected, policy must be specified, attributes 669 * will be validated in the strictest way possible. 670 * 671 * Returns 0 on success or a negative error code. 672 */ 673 static inline int nla_parse(struct nlattr **tb, int maxtype, 674 const struct nlattr *head, int len, 675 const struct nla_policy *policy, 676 struct netlink_ext_ack *extack) 677 { 678 return __nla_parse(tb, maxtype, head, len, policy, 679 NL_VALIDATE_STRICT, extack); 680 } 681 682 /** 683 * nla_parse_deprecated - 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 ignored and attributes from the policy are not 694 * always strictly validated (only for new attributes). 695 * 696 * Returns 0 on success or a negative error code. 697 */ 698 static inline int nla_parse_deprecated(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_LIBERAL, extack); 705 } 706 707 /** 708 * nla_parse_deprecated_strict - 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 rejected as well as trailing data, but the 719 * policy is not completely 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_strict(struct nlattr **tb, int maxtype, 724 const struct nlattr *head, 725 int len, 726 const struct nla_policy *policy, 727 struct netlink_ext_ack *extack) 728 { 729 return __nla_parse(tb, maxtype, head, len, policy, 730 NL_VALIDATE_DEPRECATED_STRICT, extack); 731 } 732 733 /** 734 * __nlmsg_parse - parse attributes of a netlink message 735 * @nlh: netlink message header 736 * @hdrlen: length of family specific header 737 * @tb: destination array with maxtype+1 elements 738 * @maxtype: maximum attribute type to be expected 739 * @policy: validation policy 740 * @validate: validation strictness 741 * @extack: extended ACK report struct 742 * 743 * See nla_parse() 744 */ 745 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 746 struct nlattr *tb[], int maxtype, 747 const struct nla_policy *policy, 748 unsigned int validate, 749 struct netlink_ext_ack *extack) 750 { 751 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) { 752 NL_SET_ERR_MSG(extack, "Invalid header length"); 753 return -EINVAL; 754 } 755 756 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 757 nlmsg_attrlen(nlh, hdrlen), policy, validate, 758 extack); 759 } 760 761 /** 762 * nlmsg_parse - parse attributes of a netlink message 763 * @nlh: netlink message header 764 * @hdrlen: length of family specific header 765 * @tb: destination array with maxtype+1 elements 766 * @maxtype: maximum attribute type to be expected 767 * @policy: validation policy 768 * @extack: extended ACK report struct 769 * 770 * See nla_parse() 771 */ 772 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 773 struct nlattr *tb[], int maxtype, 774 const struct nla_policy *policy, 775 struct netlink_ext_ack *extack) 776 { 777 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 778 NL_VALIDATE_STRICT, extack); 779 } 780 781 /** 782 * nlmsg_parse_deprecated - parse attributes of a netlink message 783 * @nlh: netlink message header 784 * @hdrlen: length of family specific header 785 * @tb: destination array with maxtype+1 elements 786 * @maxtype: maximum attribute type to be expected 787 * @policy: validation policy 788 * @extack: extended ACK report struct 789 * 790 * See nla_parse_deprecated() 791 */ 792 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen, 793 struct nlattr *tb[], int maxtype, 794 const struct nla_policy *policy, 795 struct netlink_ext_ack *extack) 796 { 797 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 798 NL_VALIDATE_LIBERAL, extack); 799 } 800 801 /** 802 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message 803 * @nlh: netlink message header 804 * @hdrlen: length of family specific header 805 * @tb: destination array with maxtype+1 elements 806 * @maxtype: maximum attribute type to be expected 807 * @policy: validation policy 808 * @extack: extended ACK report struct 809 * 810 * See nla_parse_deprecated_strict() 811 */ 812 static inline int 813 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen, 814 struct nlattr *tb[], int maxtype, 815 const struct nla_policy *policy, 816 struct netlink_ext_ack *extack) 817 { 818 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 819 NL_VALIDATE_DEPRECATED_STRICT, extack); 820 } 821 822 /** 823 * nlmsg_find_attr - find a specific attribute in a netlink message 824 * @nlh: netlink message header 825 * @hdrlen: length of familiy specific header 826 * @attrtype: type of attribute to look for 827 * 828 * Returns the first attribute which matches the specified type. 829 */ 830 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh, 831 int hdrlen, int attrtype) 832 { 833 return nla_find(nlmsg_attrdata(nlh, hdrlen), 834 nlmsg_attrlen(nlh, hdrlen), attrtype); 835 } 836 837 /** 838 * nla_validate_deprecated - Validate a stream of attributes 839 * @head: head of attribute stream 840 * @len: length of attribute stream 841 * @maxtype: maximum attribute type to be expected 842 * @policy: validation policy 843 * @extack: extended ACK report struct 844 * 845 * Validates all attributes in the specified attribute stream against the 846 * specified policy. Validation is done in liberal mode. 847 * See documenation of struct nla_policy for more details. 848 * 849 * Returns 0 on success or a negative error code. 850 */ 851 static inline int nla_validate_deprecated(const struct nlattr *head, int len, 852 int maxtype, 853 const struct nla_policy *policy, 854 struct netlink_ext_ack *extack) 855 { 856 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL, 857 extack); 858 } 859 860 /** 861 * nla_validate - Validate a stream of attributes 862 * @head: head of attribute stream 863 * @len: length of attribute stream 864 * @maxtype: maximum attribute type to be expected 865 * @policy: validation policy 866 * @extack: extended ACK report struct 867 * 868 * Validates all attributes in the specified attribute stream against the 869 * specified policy. Validation is done in strict mode. 870 * See documenation of struct nla_policy for more details. 871 * 872 * Returns 0 on success or a negative error code. 873 */ 874 static inline int nla_validate(const struct nlattr *head, int len, int maxtype, 875 const struct nla_policy *policy, 876 struct netlink_ext_ack *extack) 877 { 878 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT, 879 extack); 880 } 881 882 /** 883 * nlmsg_validate_deprecated - validate a netlink message including attributes 884 * @nlh: netlinket message header 885 * @hdrlen: length of familiy specific header 886 * @maxtype: maximum attribute type to be expected 887 * @policy: validation policy 888 * @extack: extended ACK report struct 889 */ 890 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh, 891 int hdrlen, int maxtype, 892 const struct nla_policy *policy, 893 struct netlink_ext_ack *extack) 894 { 895 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 896 return -EINVAL; 897 898 return __nla_validate(nlmsg_attrdata(nlh, hdrlen), 899 nlmsg_attrlen(nlh, hdrlen), maxtype, 900 policy, NL_VALIDATE_LIBERAL, extack); 901 } 902 903 904 905 /** 906 * nlmsg_report - need to report back to application? 907 * @nlh: netlink message header 908 * 909 * Returns 1 if a report back to the application is requested. 910 */ 911 static inline int nlmsg_report(const struct nlmsghdr *nlh) 912 { 913 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0; 914 } 915 916 /** 917 * nlmsg_seq - return the seq number of netlink message 918 * @nlh: netlink message header 919 * 920 * Returns 0 if netlink message is NULL 921 */ 922 static inline u32 nlmsg_seq(const struct nlmsghdr *nlh) 923 { 924 return nlh ? nlh->nlmsg_seq : 0; 925 } 926 927 /** 928 * nlmsg_for_each_attr - iterate over a stream of attributes 929 * @pos: loop counter, set to current attribute 930 * @nlh: netlink message header 931 * @hdrlen: length of familiy specific header 932 * @rem: initialized to len, holds bytes currently remaining in stream 933 */ 934 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ 935 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ 936 nlmsg_attrlen(nlh, hdrlen), rem) 937 938 /** 939 * nlmsg_put - Add a new netlink message to an skb 940 * @skb: socket buffer to store message in 941 * @portid: netlink PORTID of requesting application 942 * @seq: sequence number of message 943 * @type: message type 944 * @payload: length of message payload 945 * @flags: message flags 946 * 947 * Returns NULL if the tailroom of the skb is insufficient to store 948 * the message header and payload. 949 */ 950 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, 951 int type, int payload, int flags) 952 { 953 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) 954 return NULL; 955 956 return __nlmsg_put(skb, portid, seq, type, payload, flags); 957 } 958 959 /** 960 * nlmsg_append - Add more data to a nlmsg in a skb 961 * @skb: socket buffer to store message in 962 * @size: length of message payload 963 * 964 * Append data to an existing nlmsg, used when constructing a message 965 * with multiple fixed-format headers (which is rare). 966 * Returns NULL if the tailroom of the skb is insufficient to store 967 * the extra payload. 968 */ 969 static inline void *nlmsg_append(struct sk_buff *skb, u32 size) 970 { 971 if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size))) 972 return NULL; 973 974 if (NLMSG_ALIGN(size) - size) 975 memset(skb_tail_pointer(skb) + size, 0, 976 NLMSG_ALIGN(size) - size); 977 return __skb_put(skb, NLMSG_ALIGN(size)); 978 } 979 980 /** 981 * nlmsg_put_answer - Add a new callback based netlink message to an skb 982 * @skb: socket buffer to store message in 983 * @cb: netlink callback 984 * @type: message type 985 * @payload: length of message payload 986 * @flags: message flags 987 * 988 * Returns NULL if the tailroom of the skb is insufficient to store 989 * the message header and payload. 990 */ 991 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, 992 struct netlink_callback *cb, 993 int type, int payload, 994 int flags) 995 { 996 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 997 type, payload, flags); 998 } 999 1000 /** 1001 * nlmsg_new - Allocate a new netlink message 1002 * @payload: size of the message payload 1003 * @flags: the type of memory to allocate. 1004 * 1005 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known 1006 * and a good default is needed. 1007 */ 1008 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) 1009 { 1010 return alloc_skb(nlmsg_total_size(payload), flags); 1011 } 1012 1013 /** 1014 * nlmsg_new_large - Allocate a new netlink message with non-contiguous 1015 * physical memory 1016 * @payload: size of the message payload 1017 * 1018 * The allocated skb is unable to have frag page for shinfo->frags*, 1019 * as the NULL setting for skb->head in netlink_skb_destructor() will 1020 * bypass most of the handling in skb_release_data() 1021 */ 1022 static inline struct sk_buff *nlmsg_new_large(size_t payload) 1023 { 1024 return netlink_alloc_large_skb(nlmsg_total_size(payload), 0); 1025 } 1026 1027 /** 1028 * nlmsg_end - Finalize a netlink message 1029 * @skb: socket buffer the message is stored in 1030 * @nlh: netlink message header 1031 * 1032 * Corrects the netlink message header to include the appeneded 1033 * attributes. Only necessary if attributes have been added to 1034 * the message. 1035 */ 1036 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 1037 { 1038 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 1039 } 1040 1041 /** 1042 * nlmsg_get_pos - return current position in netlink message 1043 * @skb: socket buffer the message is stored in 1044 * 1045 * Returns a pointer to the current tail of the message. 1046 */ 1047 static inline void *nlmsg_get_pos(struct sk_buff *skb) 1048 { 1049 return skb_tail_pointer(skb); 1050 } 1051 1052 /** 1053 * nlmsg_trim - Trim message to a mark 1054 * @skb: socket buffer the message is stored in 1055 * @mark: mark to trim to 1056 * 1057 * Trims the message to the provided mark. 1058 */ 1059 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 1060 { 1061 if (mark) { 1062 WARN_ON((unsigned char *) mark < skb->data); 1063 skb_trim(skb, (unsigned char *) mark - skb->data); 1064 } 1065 } 1066 1067 /** 1068 * nlmsg_cancel - Cancel construction of a netlink message 1069 * @skb: socket buffer the message is stored in 1070 * @nlh: netlink message header 1071 * 1072 * Removes the complete netlink message including all 1073 * attributes from the socket buffer again. 1074 */ 1075 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 1076 { 1077 nlmsg_trim(skb, nlh); 1078 } 1079 1080 /** 1081 * nlmsg_free - free a netlink message 1082 * @skb: socket buffer of netlink message 1083 */ 1084 static inline void nlmsg_free(struct sk_buff *skb) 1085 { 1086 kfree_skb(skb); 1087 } 1088 1089 /** 1090 * nlmsg_multicast_filtered - multicast a netlink message with filter function 1091 * @sk: netlink socket to spread messages to 1092 * @skb: netlink message as socket buffer 1093 * @portid: own netlink portid to avoid sending to yourself 1094 * @group: multicast group id 1095 * @flags: allocation flags 1096 * @filter: filter function 1097 * @filter_data: filter function private data 1098 * 1099 * Return: 0 on success, negative error code for failure. 1100 */ 1101 static inline int nlmsg_multicast_filtered(struct sock *sk, struct sk_buff *skb, 1102 u32 portid, unsigned int group, 1103 gfp_t flags, 1104 netlink_filter_fn filter, 1105 void *filter_data) 1106 { 1107 int err; 1108 1109 NETLINK_CB(skb).dst_group = group; 1110 1111 err = netlink_broadcast_filtered(sk, skb, portid, group, flags, 1112 filter, filter_data); 1113 if (err > 0) 1114 err = 0; 1115 1116 return err; 1117 } 1118 1119 /** 1120 * nlmsg_multicast - multicast a netlink message 1121 * @sk: netlink socket to spread messages to 1122 * @skb: netlink message as socket buffer 1123 * @portid: own netlink portid to avoid sending to yourself 1124 * @group: multicast group id 1125 * @flags: allocation flags 1126 */ 1127 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 1128 u32 portid, unsigned int group, gfp_t flags) 1129 { 1130 return nlmsg_multicast_filtered(sk, skb, portid, group, flags, 1131 NULL, NULL); 1132 } 1133 1134 /** 1135 * nlmsg_unicast - unicast a netlink message 1136 * @sk: netlink socket to spread message to 1137 * @skb: netlink message as socket buffer 1138 * @portid: netlink portid of the destination socket 1139 */ 1140 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid) 1141 { 1142 int err; 1143 1144 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT); 1145 if (err > 0) 1146 err = 0; 1147 1148 return err; 1149 } 1150 1151 /** 1152 * nlmsg_for_each_msg - iterate over a stream of messages 1153 * @pos: loop counter, set to current message 1154 * @head: head of message stream 1155 * @len: length of message stream 1156 * @rem: initialized to len, holds bytes currently remaining in stream 1157 */ 1158 #define nlmsg_for_each_msg(pos, head, len, rem) \ 1159 for (pos = head, rem = len; \ 1160 nlmsg_ok(pos, rem); \ 1161 pos = nlmsg_next(pos, &(rem))) 1162 1163 /** 1164 * nl_dump_check_consistent - check if sequence is consistent and advertise if not 1165 * @cb: netlink callback structure that stores the sequence number 1166 * @nlh: netlink message header to write the flag to 1167 * 1168 * This function checks if the sequence (generation) number changed during dump 1169 * and if it did, advertises it in the netlink message header. 1170 * 1171 * The correct way to use it is to set cb->seq to the generation counter when 1172 * all locks for dumping have been acquired, and then call this function for 1173 * each message that is generated. 1174 * 1175 * Note that due to initialisation concerns, 0 is an invalid sequence number 1176 * and must not be used by code that uses this functionality. 1177 */ 1178 static inline void 1179 nl_dump_check_consistent(struct netlink_callback *cb, 1180 struct nlmsghdr *nlh) 1181 { 1182 if (cb->prev_seq && cb->seq != cb->prev_seq) 1183 nlh->nlmsg_flags |= NLM_F_DUMP_INTR; 1184 cb->prev_seq = cb->seq; 1185 } 1186 1187 /************************************************************************** 1188 * Netlink Attributes 1189 **************************************************************************/ 1190 1191 /** 1192 * nla_attr_size - length of attribute not including padding 1193 * @payload: length of payload 1194 */ 1195 static inline int nla_attr_size(int payload) 1196 { 1197 return NLA_HDRLEN + payload; 1198 } 1199 1200 /** 1201 * nla_total_size - total length of attribute including padding 1202 * @payload: length of payload 1203 */ 1204 static inline int nla_total_size(int payload) 1205 { 1206 return NLA_ALIGN(nla_attr_size(payload)); 1207 } 1208 1209 /** 1210 * nla_padlen - length of padding at the tail of attribute 1211 * @payload: length of payload 1212 */ 1213 static inline int nla_padlen(int payload) 1214 { 1215 return nla_total_size(payload) - nla_attr_size(payload); 1216 } 1217 1218 /** 1219 * nla_type - attribute type 1220 * @nla: netlink attribute 1221 */ 1222 static inline int nla_type(const struct nlattr *nla) 1223 { 1224 return nla->nla_type & NLA_TYPE_MASK; 1225 } 1226 1227 /** 1228 * nla_data - head of payload 1229 * @nla: netlink attribute 1230 */ 1231 static inline void *nla_data(const struct nlattr *nla) 1232 { 1233 return (char *) nla + NLA_HDRLEN; 1234 } 1235 1236 /** 1237 * nla_len - length of payload 1238 * @nla: netlink attribute 1239 */ 1240 static inline u16 nla_len(const struct nlattr *nla) 1241 { 1242 return nla->nla_len - NLA_HDRLEN; 1243 } 1244 1245 /** 1246 * nla_ok - check if the netlink attribute fits into the remaining bytes 1247 * @nla: netlink attribute 1248 * @remaining: number of bytes remaining in attribute stream 1249 */ 1250 static inline int nla_ok(const struct nlattr *nla, int remaining) 1251 { 1252 return remaining >= (int) sizeof(*nla) && 1253 nla->nla_len >= sizeof(*nla) && 1254 nla->nla_len <= remaining; 1255 } 1256 1257 /** 1258 * nla_next - next netlink attribute in attribute stream 1259 * @nla: netlink attribute 1260 * @remaining: number of bytes remaining in attribute stream 1261 * 1262 * Returns the next netlink attribute in the attribute stream and 1263 * decrements remaining by the size of the current attribute. 1264 */ 1265 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 1266 { 1267 unsigned int totlen = NLA_ALIGN(nla->nla_len); 1268 1269 *remaining -= totlen; 1270 return (struct nlattr *) ((char *) nla + totlen); 1271 } 1272 1273 /** 1274 * nla_find_nested - find attribute in a set of nested attributes 1275 * @nla: attribute containing the nested attributes 1276 * @attrtype: type of attribute to look for 1277 * 1278 * Returns the first attribute which matches the specified type. 1279 */ 1280 static inline struct nlattr * 1281 nla_find_nested(const struct nlattr *nla, int attrtype) 1282 { 1283 return nla_find(nla_data(nla), nla_len(nla), attrtype); 1284 } 1285 1286 /** 1287 * nla_parse_nested - parse nested attributes 1288 * @tb: destination array with maxtype+1 elements 1289 * @maxtype: maximum attribute type to be expected 1290 * @nla: attribute containing the nested attributes 1291 * @policy: validation policy 1292 * @extack: extended ACK report struct 1293 * 1294 * See nla_parse() 1295 */ 1296 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 1297 const struct nlattr *nla, 1298 const struct nla_policy *policy, 1299 struct netlink_ext_ack *extack) 1300 { 1301 if (!(nla->nla_type & NLA_F_NESTED)) { 1302 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing"); 1303 return -EINVAL; 1304 } 1305 1306 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, 1307 NL_VALIDATE_STRICT, extack); 1308 } 1309 1310 /** 1311 * nla_parse_nested_deprecated - parse nested attributes 1312 * @tb: destination array with maxtype+1 elements 1313 * @maxtype: maximum attribute type to be expected 1314 * @nla: attribute containing the nested attributes 1315 * @policy: validation policy 1316 * @extack: extended ACK report struct 1317 * 1318 * See nla_parse_deprecated() 1319 */ 1320 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype, 1321 const struct nlattr *nla, 1322 const struct nla_policy *policy, 1323 struct netlink_ext_ack *extack) 1324 { 1325 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, 1326 NL_VALIDATE_LIBERAL, extack); 1327 } 1328 1329 /** 1330 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 1331 * @skb: socket buffer to add attribute to 1332 * @attrtype: attribute type 1333 * @value: numeric value 1334 */ 1335 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 1336 { 1337 /* temporary variables to work around GCC PR81715 with asan-stack=1 */ 1338 u8 tmp = value; 1339 1340 return nla_put(skb, attrtype, sizeof(u8), &tmp); 1341 } 1342 1343 /** 1344 * nla_put_u16 - Add a u16 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_u16(struct sk_buff *skb, int attrtype, u16 value) 1350 { 1351 u16 tmp = value; 1352 1353 return nla_put(skb, attrtype, sizeof(u16), &tmp); 1354 } 1355 1356 /** 1357 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer 1358 * @skb: socket buffer to add attribute to 1359 * @attrtype: attribute type 1360 * @value: numeric value 1361 */ 1362 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value) 1363 { 1364 __be16 tmp = value; 1365 1366 return nla_put(skb, attrtype, sizeof(__be16), &tmp); 1367 } 1368 1369 /** 1370 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer 1371 * @skb: socket buffer to add attribute to 1372 * @attrtype: attribute type 1373 * @value: numeric value 1374 */ 1375 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value) 1376 { 1377 __be16 tmp = value; 1378 1379 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 1380 } 1381 1382 /** 1383 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer 1384 * @skb: socket buffer to add attribute to 1385 * @attrtype: attribute type 1386 * @value: numeric value 1387 */ 1388 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value) 1389 { 1390 __le16 tmp = value; 1391 1392 return nla_put(skb, attrtype, sizeof(__le16), &tmp); 1393 } 1394 1395 /** 1396 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 1397 * @skb: socket buffer to add attribute to 1398 * @attrtype: attribute type 1399 * @value: numeric value 1400 */ 1401 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 1402 { 1403 u32 tmp = value; 1404 1405 return nla_put(skb, attrtype, sizeof(u32), &tmp); 1406 } 1407 1408 /** 1409 * nla_put_uint - Add a variable-size unsigned int to a socket buffer 1410 * @skb: socket buffer to add attribute to 1411 * @attrtype: attribute type 1412 * @value: numeric value 1413 */ 1414 static inline int nla_put_uint(struct sk_buff *skb, int attrtype, u64 value) 1415 { 1416 u64 tmp64 = value; 1417 u32 tmp32 = value; 1418 1419 if (tmp64 == tmp32) 1420 return nla_put_u32(skb, attrtype, tmp32); 1421 return nla_put(skb, attrtype, sizeof(u64), &tmp64); 1422 } 1423 1424 /** 1425 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer 1426 * @skb: socket buffer to add attribute to 1427 * @attrtype: attribute type 1428 * @value: numeric value 1429 */ 1430 static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value) 1431 { 1432 __be32 tmp = value; 1433 1434 return nla_put(skb, attrtype, sizeof(__be32), &tmp); 1435 } 1436 1437 /** 1438 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer 1439 * @skb: socket buffer to add attribute to 1440 * @attrtype: attribute type 1441 * @value: numeric value 1442 */ 1443 static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value) 1444 { 1445 __be32 tmp = value; 1446 1447 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 1448 } 1449 1450 /** 1451 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer 1452 * @skb: socket buffer to add attribute to 1453 * @attrtype: attribute type 1454 * @value: numeric value 1455 */ 1456 static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value) 1457 { 1458 __le32 tmp = value; 1459 1460 return nla_put(skb, attrtype, sizeof(__le32), &tmp); 1461 } 1462 1463 /** 1464 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it 1465 * @skb: socket buffer to add attribute to 1466 * @attrtype: attribute type 1467 * @value: numeric value 1468 * @padattr: attribute type for the padding 1469 */ 1470 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype, 1471 u64 value, int padattr) 1472 { 1473 u64 tmp = value; 1474 1475 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1476 } 1477 1478 /** 1479 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it 1480 * @skb: socket buffer to add attribute to 1481 * @attrtype: attribute type 1482 * @value: numeric value 1483 * @padattr: attribute type for the padding 1484 */ 1485 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value, 1486 int padattr) 1487 { 1488 __be64 tmp = value; 1489 1490 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr); 1491 } 1492 1493 /** 1494 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it 1495 * @skb: socket buffer to add attribute to 1496 * @attrtype: attribute type 1497 * @value: numeric value 1498 * @padattr: attribute type for the padding 1499 */ 1500 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value, 1501 int padattr) 1502 { 1503 __be64 tmp = value; 1504 1505 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp, 1506 padattr); 1507 } 1508 1509 /** 1510 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it 1511 * @skb: socket buffer to add attribute to 1512 * @attrtype: attribute type 1513 * @value: numeric value 1514 * @padattr: attribute type for the padding 1515 */ 1516 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value, 1517 int padattr) 1518 { 1519 __le64 tmp = value; 1520 1521 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr); 1522 } 1523 1524 /** 1525 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer 1526 * @skb: socket buffer to add attribute to 1527 * @attrtype: attribute type 1528 * @value: numeric value 1529 */ 1530 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value) 1531 { 1532 s8 tmp = value; 1533 1534 return nla_put(skb, attrtype, sizeof(s8), &tmp); 1535 } 1536 1537 /** 1538 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer 1539 * @skb: socket buffer to add attribute to 1540 * @attrtype: attribute type 1541 * @value: numeric value 1542 */ 1543 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value) 1544 { 1545 s16 tmp = value; 1546 1547 return nla_put(skb, attrtype, sizeof(s16), &tmp); 1548 } 1549 1550 /** 1551 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer 1552 * @skb: socket buffer to add attribute to 1553 * @attrtype: attribute type 1554 * @value: numeric value 1555 */ 1556 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value) 1557 { 1558 s32 tmp = value; 1559 1560 return nla_put(skb, attrtype, sizeof(s32), &tmp); 1561 } 1562 1563 /** 1564 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it 1565 * @skb: socket buffer to add attribute to 1566 * @attrtype: attribute type 1567 * @value: numeric value 1568 * @padattr: attribute type for the padding 1569 */ 1570 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value, 1571 int padattr) 1572 { 1573 s64 tmp = value; 1574 1575 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr); 1576 } 1577 1578 /** 1579 * nla_put_sint - Add a variable-size signed int to a socket buffer 1580 * @skb: socket buffer to add attribute to 1581 * @attrtype: attribute type 1582 * @value: numeric value 1583 */ 1584 static inline int nla_put_sint(struct sk_buff *skb, int attrtype, s64 value) 1585 { 1586 s64 tmp64 = value; 1587 s32 tmp32 = value; 1588 1589 if (tmp64 == tmp32) 1590 return nla_put_s32(skb, attrtype, tmp32); 1591 return nla_put(skb, attrtype, sizeof(s64), &tmp64); 1592 } 1593 1594 /** 1595 * nla_put_string - Add a string netlink attribute to a socket buffer 1596 * @skb: socket buffer to add attribute to 1597 * @attrtype: attribute type 1598 * @str: NUL terminated string 1599 */ 1600 static inline int nla_put_string(struct sk_buff *skb, int attrtype, 1601 const char *str) 1602 { 1603 return nla_put(skb, attrtype, strlen(str) + 1, str); 1604 } 1605 1606 /** 1607 * nla_put_flag - Add a flag netlink attribute to a socket buffer 1608 * @skb: socket buffer to add attribute to 1609 * @attrtype: attribute type 1610 */ 1611 static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 1612 { 1613 return nla_put(skb, attrtype, 0, NULL); 1614 } 1615 1616 /** 1617 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it 1618 * @skb: socket buffer to add attribute to 1619 * @attrtype: attribute type 1620 * @njiffies: number of jiffies to convert to msecs 1621 * @padattr: attribute type for the padding 1622 */ 1623 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 1624 unsigned long njiffies, int padattr) 1625 { 1626 u64 tmp = jiffies_to_msecs(njiffies); 1627 1628 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1629 } 1630 1631 /** 1632 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket 1633 * buffer 1634 * @skb: socket buffer to add attribute to 1635 * @attrtype: attribute type 1636 * @addr: IPv4 address 1637 */ 1638 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype, 1639 __be32 addr) 1640 { 1641 __be32 tmp = addr; 1642 1643 return nla_put_be32(skb, attrtype, tmp); 1644 } 1645 1646 /** 1647 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket 1648 * buffer 1649 * @skb: socket buffer to add attribute to 1650 * @attrtype: attribute type 1651 * @addr: IPv6 address 1652 */ 1653 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype, 1654 const struct in6_addr *addr) 1655 { 1656 return nla_put(skb, attrtype, sizeof(*addr), addr); 1657 } 1658 1659 /** 1660 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer 1661 * @skb: socket buffer to add attribute to 1662 * @attrtype: attribute type 1663 * @value: value carrying bits 1664 * @selector: selector of valid bits 1665 */ 1666 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype, 1667 __u32 value, __u32 selector) 1668 { 1669 struct nla_bitfield32 tmp = { value, selector, }; 1670 1671 return nla_put(skb, attrtype, sizeof(tmp), &tmp); 1672 } 1673 1674 /** 1675 * nla_get_u32 - return payload of u32 attribute 1676 * @nla: u32 netlink attribute 1677 */ 1678 static inline u32 nla_get_u32(const struct nlattr *nla) 1679 { 1680 return *(u32 *) nla_data(nla); 1681 } 1682 1683 /** 1684 * nla_get_be32 - return payload of __be32 attribute 1685 * @nla: __be32 netlink attribute 1686 */ 1687 static inline __be32 nla_get_be32(const struct nlattr *nla) 1688 { 1689 return *(__be32 *) nla_data(nla); 1690 } 1691 1692 /** 1693 * nla_get_le32 - return payload of __le32 attribute 1694 * @nla: __le32 netlink attribute 1695 */ 1696 static inline __le32 nla_get_le32(const struct nlattr *nla) 1697 { 1698 return *(__le32 *) nla_data(nla); 1699 } 1700 1701 /** 1702 * nla_get_u16 - return payload of u16 attribute 1703 * @nla: u16 netlink attribute 1704 */ 1705 static inline u16 nla_get_u16(const struct nlattr *nla) 1706 { 1707 return *(u16 *) nla_data(nla); 1708 } 1709 1710 /** 1711 * nla_get_be16 - return payload of __be16 attribute 1712 * @nla: __be16 netlink attribute 1713 */ 1714 static inline __be16 nla_get_be16(const struct nlattr *nla) 1715 { 1716 return *(__be16 *) nla_data(nla); 1717 } 1718 1719 /** 1720 * nla_get_le16 - return payload of __le16 attribute 1721 * @nla: __le16 netlink attribute 1722 */ 1723 static inline __le16 nla_get_le16(const struct nlattr *nla) 1724 { 1725 return *(__le16 *) nla_data(nla); 1726 } 1727 1728 /** 1729 * nla_get_u8 - return payload of u8 attribute 1730 * @nla: u8 netlink attribute 1731 */ 1732 static inline u8 nla_get_u8(const struct nlattr *nla) 1733 { 1734 return *(u8 *) nla_data(nla); 1735 } 1736 1737 /** 1738 * nla_get_u64 - return payload of u64 attribute 1739 * @nla: u64 netlink attribute 1740 */ 1741 static inline u64 nla_get_u64(const struct nlattr *nla) 1742 { 1743 u64 tmp; 1744 1745 nla_memcpy(&tmp, nla, sizeof(tmp)); 1746 1747 return tmp; 1748 } 1749 1750 /** 1751 * nla_get_uint - return payload of uint attribute 1752 * @nla: uint netlink attribute 1753 */ 1754 static inline u64 nla_get_uint(const struct nlattr *nla) 1755 { 1756 if (nla_len(nla) == sizeof(u32)) 1757 return nla_get_u32(nla); 1758 return nla_get_u64(nla); 1759 } 1760 1761 /** 1762 * nla_get_be64 - return payload of __be64 attribute 1763 * @nla: __be64 netlink attribute 1764 */ 1765 static inline __be64 nla_get_be64(const struct nlattr *nla) 1766 { 1767 __be64 tmp; 1768 1769 nla_memcpy(&tmp, nla, sizeof(tmp)); 1770 1771 return tmp; 1772 } 1773 1774 /** 1775 * nla_get_le64 - return payload of __le64 attribute 1776 * @nla: __le64 netlink attribute 1777 */ 1778 static inline __le64 nla_get_le64(const struct nlattr *nla) 1779 { 1780 return *(__le64 *) nla_data(nla); 1781 } 1782 1783 /** 1784 * nla_get_s32 - return payload of s32 attribute 1785 * @nla: s32 netlink attribute 1786 */ 1787 static inline s32 nla_get_s32(const struct nlattr *nla) 1788 { 1789 return *(s32 *) nla_data(nla); 1790 } 1791 1792 /** 1793 * nla_get_s16 - return payload of s16 attribute 1794 * @nla: s16 netlink attribute 1795 */ 1796 static inline s16 nla_get_s16(const struct nlattr *nla) 1797 { 1798 return *(s16 *) nla_data(nla); 1799 } 1800 1801 /** 1802 * nla_get_s8 - return payload of s8 attribute 1803 * @nla: s8 netlink attribute 1804 */ 1805 static inline s8 nla_get_s8(const struct nlattr *nla) 1806 { 1807 return *(s8 *) nla_data(nla); 1808 } 1809 1810 /** 1811 * nla_get_s64 - return payload of s64 attribute 1812 * @nla: s64 netlink attribute 1813 */ 1814 static inline s64 nla_get_s64(const struct nlattr *nla) 1815 { 1816 s64 tmp; 1817 1818 nla_memcpy(&tmp, nla, sizeof(tmp)); 1819 1820 return tmp; 1821 } 1822 1823 /** 1824 * nla_get_sint - return payload of uint attribute 1825 * @nla: uint netlink attribute 1826 */ 1827 static inline s64 nla_get_sint(const struct nlattr *nla) 1828 { 1829 if (nla_len(nla) == sizeof(s32)) 1830 return nla_get_s32(nla); 1831 return nla_get_s64(nla); 1832 } 1833 1834 /** 1835 * nla_get_flag - return payload of flag attribute 1836 * @nla: flag netlink attribute 1837 */ 1838 static inline int nla_get_flag(const struct nlattr *nla) 1839 { 1840 return !!nla; 1841 } 1842 1843 /** 1844 * nla_get_msecs - return payload of msecs attribute 1845 * @nla: msecs netlink attribute 1846 * 1847 * Returns the number of milliseconds in jiffies. 1848 */ 1849 static inline unsigned long nla_get_msecs(const struct nlattr *nla) 1850 { 1851 u64 msecs = nla_get_u64(nla); 1852 1853 return msecs_to_jiffies((unsigned long) msecs); 1854 } 1855 1856 /** 1857 * nla_get_in_addr - return payload of IPv4 address attribute 1858 * @nla: IPv4 address netlink attribute 1859 */ 1860 static inline __be32 nla_get_in_addr(const struct nlattr *nla) 1861 { 1862 return *(__be32 *) nla_data(nla); 1863 } 1864 1865 /** 1866 * nla_get_in6_addr - return payload of IPv6 address attribute 1867 * @nla: IPv6 address netlink attribute 1868 */ 1869 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla) 1870 { 1871 struct in6_addr tmp; 1872 1873 nla_memcpy(&tmp, nla, sizeof(tmp)); 1874 return tmp; 1875 } 1876 1877 /** 1878 * nla_get_bitfield32 - return payload of 32 bitfield attribute 1879 * @nla: nla_bitfield32 attribute 1880 */ 1881 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla) 1882 { 1883 struct nla_bitfield32 tmp; 1884 1885 nla_memcpy(&tmp, nla, sizeof(tmp)); 1886 return tmp; 1887 } 1888 1889 /** 1890 * nla_memdup - duplicate attribute memory (kmemdup) 1891 * @src: netlink attribute to duplicate from 1892 * @gfp: GFP mask 1893 */ 1894 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp) 1895 { 1896 return kmemdup(nla_data(src), nla_len(src), gfp); 1897 } 1898 1899 /** 1900 * nla_nest_start_noflag - Start a new level of nested attributes 1901 * @skb: socket buffer to add attributes to 1902 * @attrtype: attribute type of container 1903 * 1904 * This function exists for backward compatibility to use in APIs which never 1905 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use 1906 * nla_nest_start() which sets the flag. 1907 * 1908 * Returns the container attribute or NULL on error 1909 */ 1910 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb, 1911 int attrtype) 1912 { 1913 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 1914 1915 if (nla_put(skb, attrtype, 0, NULL) < 0) 1916 return NULL; 1917 1918 return start; 1919 } 1920 1921 /** 1922 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED 1923 * @skb: socket buffer to add attributes to 1924 * @attrtype: attribute type of container 1925 * 1926 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED 1927 * flag. This is the preferred function to use in new code. 1928 * 1929 * Returns the container attribute or NULL on error 1930 */ 1931 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 1932 { 1933 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED); 1934 } 1935 1936 /** 1937 * nla_nest_end - Finalize nesting of attributes 1938 * @skb: socket buffer the attributes are stored in 1939 * @start: container attribute 1940 * 1941 * Corrects the container attribute header to include the all 1942 * appeneded attributes. 1943 * 1944 * Returns the total data length of the skb. 1945 */ 1946 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 1947 { 1948 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1949 return skb->len; 1950 } 1951 1952 /** 1953 * nla_nest_cancel - Cancel nesting of attributes 1954 * @skb: socket buffer the message is stored in 1955 * @start: container attribute 1956 * 1957 * Removes the container attribute and including all nested 1958 * attributes. Returns -EMSGSIZE 1959 */ 1960 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 1961 { 1962 nlmsg_trim(skb, start); 1963 } 1964 1965 /** 1966 * __nla_validate_nested - Validate a stream of nested attributes 1967 * @start: container attribute 1968 * @maxtype: maximum attribute type to be expected 1969 * @policy: validation policy 1970 * @validate: validation strictness 1971 * @extack: extended ACK report struct 1972 * 1973 * Validates all attributes in the nested attribute stream against the 1974 * specified policy. Attributes with a type exceeding maxtype will be 1975 * ignored. See documenation of struct nla_policy for more details. 1976 * 1977 * Returns 0 on success or a negative error code. 1978 */ 1979 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype, 1980 const struct nla_policy *policy, 1981 unsigned int validate, 1982 struct netlink_ext_ack *extack) 1983 { 1984 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy, 1985 validate, extack); 1986 } 1987 1988 static inline int 1989 nla_validate_nested(const struct nlattr *start, int maxtype, 1990 const struct nla_policy *policy, 1991 struct netlink_ext_ack *extack) 1992 { 1993 return __nla_validate_nested(start, maxtype, policy, 1994 NL_VALIDATE_STRICT, extack); 1995 } 1996 1997 static inline int 1998 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype, 1999 const struct nla_policy *policy, 2000 struct netlink_ext_ack *extack) 2001 { 2002 return __nla_validate_nested(start, maxtype, policy, 2003 NL_VALIDATE_LIBERAL, extack); 2004 } 2005 2006 /** 2007 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute 2008 * @skb: socket buffer the message is stored in 2009 * 2010 * Return true if padding is needed to align the next attribute (nla_data()) to 2011 * a 64-bit aligned area. 2012 */ 2013 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb) 2014 { 2015 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2016 /* The nlattr header is 4 bytes in size, that's why we test 2017 * if the skb->data _is_ aligned. A NOP attribute, plus 2018 * nlattr header for next attribute, will make nla_data() 2019 * 8-byte aligned. 2020 */ 2021 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8)) 2022 return true; 2023 #endif 2024 return false; 2025 } 2026 2027 /** 2028 * nla_align_64bit - 64-bit align the nla_data() of next attribute 2029 * @skb: socket buffer the message is stored in 2030 * @padattr: attribute type for the padding 2031 * 2032 * Conditionally emit a padding netlink attribute in order to make 2033 * the next attribute we emit have a 64-bit aligned nla_data() area. 2034 * This will only be done in architectures which do not have 2035 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined. 2036 * 2037 * Returns zero on success or a negative error code. 2038 */ 2039 static inline int nla_align_64bit(struct sk_buff *skb, int padattr) 2040 { 2041 if (nla_need_padding_for_64bit(skb) && 2042 !nla_reserve(skb, padattr, 0)) 2043 return -EMSGSIZE; 2044 2045 return 0; 2046 } 2047 2048 /** 2049 * nla_total_size_64bit - total length of attribute including padding 2050 * @payload: length of payload 2051 */ 2052 static inline int nla_total_size_64bit(int payload) 2053 { 2054 return NLA_ALIGN(nla_attr_size(payload)) 2055 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2056 + NLA_ALIGN(nla_attr_size(0)) 2057 #endif 2058 ; 2059 } 2060 2061 /** 2062 * nla_for_each_attr - iterate over a stream of attributes 2063 * @pos: loop counter, set to current attribute 2064 * @head: head of attribute stream 2065 * @len: length of attribute stream 2066 * @rem: initialized to len, holds bytes currently remaining in stream 2067 */ 2068 #define nla_for_each_attr(pos, head, len, rem) \ 2069 for (pos = head, rem = len; \ 2070 nla_ok(pos, rem); \ 2071 pos = nla_next(pos, &(rem))) 2072 2073 /** 2074 * nla_for_each_nested - iterate over nested attributes 2075 * @pos: loop counter, set to current attribute 2076 * @nla: attribute containing the nested attributes 2077 * @rem: initialized to len, holds bytes currently remaining in stream 2078 */ 2079 #define nla_for_each_nested(pos, nla, rem) \ 2080 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 2081 2082 /** 2083 * nla_is_last - Test if attribute is last in stream 2084 * @nla: attribute to test 2085 * @rem: bytes remaining in stream 2086 */ 2087 static inline bool nla_is_last(const struct nlattr *nla, int rem) 2088 { 2089 return nla->nla_len == rem; 2090 } 2091 2092 void nla_get_range_unsigned(const struct nla_policy *pt, 2093 struct netlink_range_validation *range); 2094 void nla_get_range_signed(const struct nla_policy *pt, 2095 struct netlink_range_validation_signed *range); 2096 2097 struct netlink_policy_dump_state; 2098 2099 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate, 2100 const struct nla_policy *policy, 2101 unsigned int maxtype); 2102 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state, 2103 const struct nla_policy *policy, 2104 unsigned int maxtype); 2105 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state); 2106 int netlink_policy_dump_write(struct sk_buff *skb, 2107 struct netlink_policy_dump_state *state); 2108 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt); 2109 int netlink_policy_dump_write_attr(struct sk_buff *skb, 2110 const struct nla_policy *pt, 2111 int nestattr); 2112 void netlink_policy_dump_free(struct netlink_policy_dump_state *state); 2113 2114 #endif 2115