1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __NET_NETLINK_H 3 #define __NET_NETLINK_H 4 5 #include <linux/types.h> 6 #include <linux/netlink.h> 7 #include <linux/jiffies.h> 8 #include <linux/in6.h> 9 10 /* ======================================================================== 11 * Netlink Messages and Attributes Interface (As Seen On TV) 12 * ------------------------------------------------------------------------ 13 * Messages Interface 14 * ------------------------------------------------------------------------ 15 * 16 * Message Format: 17 * <--- nlmsg_total_size(payload) ---> 18 * <-- nlmsg_msg_size(payload) -> 19 * +----------+- - -+-------------+- - -+-------- - - 20 * | nlmsghdr | Pad | Payload | Pad | nlmsghdr 21 * +----------+- - -+-------------+- - -+-------- - - 22 * nlmsg_data(nlh)---^ ^ 23 * nlmsg_next(nlh)-----------------------+ 24 * 25 * Payload Format: 26 * <---------------------- nlmsg_len(nlh) ---------------------> 27 * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) -> 28 * +----------------------+- - -+--------------------------------+ 29 * | Family Header | Pad | Attributes | 30 * +----------------------+- - -+--------------------------------+ 31 * nlmsg_attrdata(nlh, hdrlen)---^ 32 * 33 * Data Structures: 34 * struct nlmsghdr netlink message header 35 * 36 * Message Construction: 37 * nlmsg_new() create a new netlink message 38 * nlmsg_put() add a netlink message to an skb 39 * nlmsg_put_answer() callback based nlmsg_put() 40 * nlmsg_end() finalize netlink message 41 * nlmsg_get_pos() return current position in message 42 * nlmsg_trim() trim part of message 43 * nlmsg_cancel() cancel message construction 44 * nlmsg_free() free a netlink message 45 * 46 * Message Sending: 47 * nlmsg_multicast() multicast message to several groups 48 * nlmsg_unicast() unicast a message to a single socket 49 * nlmsg_notify() send notification message 50 * 51 * Message Length Calculations: 52 * nlmsg_msg_size(payload) length of message w/o padding 53 * nlmsg_total_size(payload) length of message w/ padding 54 * nlmsg_padlen(payload) length of padding at tail 55 * 56 * Message Payload Access: 57 * nlmsg_data(nlh) head of message payload 58 * nlmsg_len(nlh) length of message payload 59 * nlmsg_attrdata(nlh, hdrlen) head of attributes data 60 * nlmsg_attrlen(nlh, hdrlen) length of attributes data 61 * 62 * Message Parsing: 63 * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes? 64 * nlmsg_next(nlh, remaining) get next netlink message 65 * nlmsg_parse() parse attributes of a message 66 * nlmsg_find_attr() find an attribute in a message 67 * nlmsg_for_each_msg() loop over all messages 68 * nlmsg_validate() validate netlink message incl. attrs 69 * nlmsg_for_each_attr() loop over all attributes 70 * 71 * Misc: 72 * nlmsg_report() report back to application? 73 * 74 * ------------------------------------------------------------------------ 75 * Attributes Interface 76 * ------------------------------------------------------------------------ 77 * 78 * Attribute Format: 79 * <------- nla_total_size(payload) -------> 80 * <---- nla_attr_size(payload) -----> 81 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 82 * | Header | Pad | Payload | Pad | Header 83 * +----------+- - -+- - - - - - - - - +- - -+-------- - - 84 * <- nla_len(nla) -> ^ 85 * nla_data(nla)----^ | 86 * nla_next(nla)-----------------------------' 87 * 88 * Data Structures: 89 * struct nlattr netlink attribute header 90 * 91 * Attribute Construction: 92 * nla_reserve(skb, type, len) reserve room for an attribute 93 * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr 94 * nla_put(skb, type, len, data) add attribute to skb 95 * nla_put_nohdr(skb, len, data) add attribute w/o hdr 96 * nla_append(skb, len, data) append data to skb 97 * 98 * Attribute Construction for Basic Types: 99 * nla_put_u8(skb, type, value) add u8 attribute to skb 100 * nla_put_u16(skb, type, value) add u16 attribute to skb 101 * nla_put_u32(skb, type, value) add u32 attribute to skb 102 * nla_put_u64_64bit(skb, type, 103 * value, padattr) add u64 attribute to skb 104 * nla_put_s8(skb, type, value) add s8 attribute to skb 105 * nla_put_s16(skb, type, value) add s16 attribute to skb 106 * nla_put_s32(skb, type, value) add s32 attribute to skb 107 * nla_put_s64(skb, type, value, 108 * padattr) add s64 attribute to skb 109 * nla_put_string(skb, type, str) add string attribute to skb 110 * nla_put_flag(skb, type) add flag attribute to skb 111 * nla_put_msecs(skb, type, jiffies, 112 * padattr) add msecs attribute to skb 113 * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb 114 * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb 115 * 116 * Nested Attributes Construction: 117 * nla_nest_start(skb, type) start a nested attribute 118 * nla_nest_end(skb, nla) finalize a nested attribute 119 * nla_nest_cancel(skb, nla) cancel nested attribute construction 120 * 121 * Attribute Length Calculations: 122 * nla_attr_size(payload) length of attribute w/o padding 123 * nla_total_size(payload) length of attribute w/ padding 124 * nla_padlen(payload) length of padding 125 * 126 * Attribute Payload Access: 127 * nla_data(nla) head of attribute payload 128 * nla_len(nla) length of attribute payload 129 * 130 * Attribute Payload Access for Basic Types: 131 * nla_get_u8(nla) get payload for a u8 attribute 132 * nla_get_u16(nla) get payload for a u16 attribute 133 * nla_get_u32(nla) get payload for a u32 attribute 134 * nla_get_u64(nla) get payload for a u64 attribute 135 * nla_get_s8(nla) get payload for a s8 attribute 136 * nla_get_s16(nla) get payload for a s16 attribute 137 * nla_get_s32(nla) get payload for a s32 attribute 138 * nla_get_s64(nla) get payload for a s64 attribute 139 * nla_get_flag(nla) return 1 if flag is true 140 * nla_get_msecs(nla) get payload for a msecs attribute 141 * 142 * Attribute Misc: 143 * nla_memcpy(dest, nla, count) copy attribute into memory 144 * nla_memcmp(nla, data, size) compare attribute with memory area 145 * nla_strscpy(dst, nla, size) copy attribute to a sized string 146 * nla_strcmp(nla, str) compare attribute with string 147 * 148 * Attribute Parsing: 149 * nla_ok(nla, remaining) does nla fit into remaining bytes? 150 * nla_next(nla, remaining) get next netlink attribute 151 * nla_validate() validate a stream of attributes 152 * nla_validate_nested() validate a stream of nested attributes 153 * nla_find() find attribute in stream of attributes 154 * nla_find_nested() find attribute in nested attributes 155 * nla_parse() parse and validate stream of attrs 156 * nla_parse_nested() parse nested attributes 157 * nla_for_each_attr() loop over all attributes 158 * nla_for_each_nested() loop over the nested attributes 159 *========================================================================= 160 */ 161 162 /** 163 * Standard attribute types to specify validation policy 164 */ 165 enum { 166 NLA_UNSPEC, 167 NLA_U8, 168 NLA_U16, 169 NLA_U32, 170 NLA_U64, 171 NLA_STRING, 172 NLA_FLAG, 173 NLA_MSECS, 174 NLA_NESTED, 175 NLA_NESTED_ARRAY, 176 NLA_NUL_STRING, 177 NLA_BINARY, 178 NLA_S8, 179 NLA_S16, 180 NLA_S32, 181 NLA_S64, 182 NLA_BITFIELD32, 183 NLA_REJECT, 184 __NLA_TYPE_MAX, 185 }; 186 187 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) 188 189 struct netlink_range_validation { 190 u64 min, max; 191 }; 192 193 struct netlink_range_validation_signed { 194 s64 min, max; 195 }; 196 197 enum nla_policy_validation { 198 NLA_VALIDATE_NONE, 199 NLA_VALIDATE_RANGE, 200 NLA_VALIDATE_RANGE_WARN_TOO_LONG, 201 NLA_VALIDATE_MIN, 202 NLA_VALIDATE_MAX, 203 NLA_VALIDATE_MASK, 204 NLA_VALIDATE_RANGE_PTR, 205 NLA_VALIDATE_FUNCTION, 206 }; 207 208 /** 209 * struct nla_policy - attribute validation policy 210 * @type: Type of attribute or NLA_UNSPEC 211 * @validation_type: type of attribute validation done in addition to 212 * type-specific validation (e.g. range, function call), see 213 * &enum nla_policy_validation 214 * @len: Type specific length of payload 215 * 216 * Policies are defined as arrays of this struct, the array must be 217 * accessible by attribute type up to the highest identifier to be expected. 218 * 219 * Meaning of `len' field: 220 * NLA_STRING Maximum length of string 221 * NLA_NUL_STRING Maximum length of string (excluding NUL) 222 * NLA_FLAG Unused 223 * NLA_BINARY Maximum length of attribute payload 224 * (but see also below with the validation type) 225 * NLA_NESTED, 226 * NLA_NESTED_ARRAY Length verification is done by checking len of 227 * nested header (or empty); len field is used if 228 * nested_policy is also used, for the max attr 229 * number in the nested policy. 230 * NLA_U8, NLA_U16, 231 * NLA_U32, NLA_U64, 232 * NLA_S8, NLA_S16, 233 * NLA_S32, NLA_S64, 234 * NLA_MSECS Leaving the length field zero will verify the 235 * given type fits, using it verifies minimum length 236 * just like "All other" 237 * NLA_BITFIELD32 Unused 238 * NLA_REJECT Unused 239 * All other Minimum length of attribute payload 240 * 241 * Meaning of validation union: 242 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and 243 * `bitfield32_valid' is the u32 value of valid flags 244 * NLA_REJECT This attribute is always rejected and `reject_message' 245 * may point to a string to report as the error instead 246 * of the generic one in extended ACK. 247 * NLA_NESTED `nested_policy' to a nested policy to validate, must 248 * also set `len' to the max attribute number. Use the 249 * provided NLA_POLICY_NESTED() macro. 250 * Note that nla_parse() will validate, but of course not 251 * parse, the nested sub-policies. 252 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate, 253 * must also set `len' to the max attribute number. Use 254 * the provided NLA_POLICY_NESTED_ARRAY() macro. 255 * The difference to NLA_NESTED is the structure: 256 * NLA_NESTED has the nested attributes directly inside 257 * while an array has the nested attributes at another 258 * level down and the attribute types directly in the 259 * nesting don't matter. 260 * NLA_U8, 261 * NLA_U16, 262 * NLA_U32, 263 * NLA_U64, 264 * NLA_S8, 265 * NLA_S16, 266 * NLA_S32, 267 * NLA_S64 The `min' and `max' fields are used depending on the 268 * validation_type field, if that is min/max/range then 269 * the min, max or both are used (respectively) to check 270 * the value of the integer attribute. 271 * Note that in the interest of code simplicity and 272 * struct size both limits are s16, so you cannot 273 * enforce a range that doesn't fall within the range 274 * of s16 - do that as usual in the code instead. 275 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and 276 * NLA_POLICY_RANGE() macros. 277 * NLA_U8, 278 * NLA_U16, 279 * NLA_U32, 280 * NLA_U64 If the validation_type field instead is set to 281 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer 282 * to a struct netlink_range_validation that indicates 283 * the min/max values. 284 * Use NLA_POLICY_FULL_RANGE(). 285 * NLA_S8, 286 * NLA_S16, 287 * NLA_S32, 288 * NLA_S64 If the validation_type field instead is set to 289 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a 290 * pointer to a struct netlink_range_validation_signed 291 * that indicates the min/max values. 292 * Use NLA_POLICY_FULL_RANGE_SIGNED(). 293 * 294 * NLA_BINARY If the validation type is like the ones for integers 295 * above, then the min/max length (not value like for 296 * integers) of the attribute is enforced. 297 * 298 * All other Unused - but note that it's a union 299 * 300 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN: 301 * NLA_BINARY Validation function called for the attribute. 302 * All other Unused - but note that it's a union 303 * 304 * Example: 305 * 306 * static const u32 myvalidflags = 0xff231023; 307 * 308 * static const struct nla_policy my_policy[ATTR_MAX+1] = { 309 * [ATTR_FOO] = { .type = NLA_U16 }, 310 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, 311 * [ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)), 312 * [ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags), 313 * }; 314 */ 315 struct nla_policy { 316 u8 type; 317 u8 validation_type; 318 u16 len; 319 union { 320 const u32 bitfield32_valid; 321 const u32 mask; 322 const char *reject_message; 323 const struct nla_policy *nested_policy; 324 struct netlink_range_validation *range; 325 struct netlink_range_validation_signed *range_signed; 326 struct { 327 s16 min, max; 328 u8 network_byte_order:1; 329 }; 330 int (*validate)(const struct nlattr *attr, 331 struct netlink_ext_ack *extack); 332 /* This entry is special, and used for the attribute at index 0 333 * only, and specifies special data about the policy, namely it 334 * specifies the "boundary type" where strict length validation 335 * starts for any attribute types >= this value, also, strict 336 * nesting validation starts here. 337 * 338 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT 339 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to 340 * get the previous pure { .len = xyz } behaviour. The advantage 341 * of this is that types not specified in the policy will be 342 * rejected. 343 * 344 * For completely new families it should be set to 1 so that the 345 * validation is enforced for all attributes. For existing ones 346 * it should be set at least when new attributes are added to 347 * the enum used by the policy, and be set to the new value that 348 * was added to enforce strict validation from thereon. 349 */ 350 u16 strict_start_type; 351 }; 352 }; 353 354 #define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) 355 #define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) 356 357 #define _NLA_POLICY_NESTED(maxattr, policy) \ 358 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr } 359 #define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ 360 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr } 361 #define NLA_POLICY_NESTED(policy) \ 362 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy) 363 #define NLA_POLICY_NESTED_ARRAY(policy) \ 364 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy) 365 #define NLA_POLICY_BITFIELD32(valid) \ 366 { .type = NLA_BITFIELD32, .bitfield32_valid = valid } 367 368 #define __NLA_IS_UINT_TYPE(tp) \ 369 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || tp == NLA_U64) 370 #define __NLA_IS_SINT_TYPE(tp) \ 371 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64) 372 373 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition)) 374 #define NLA_ENSURE_UINT_TYPE(tp) \ 375 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp)) + tp) 376 #define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \ 377 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \ 378 tp == NLA_MSECS || \ 379 tp == NLA_BINARY) + tp) 380 #define NLA_ENSURE_SINT_TYPE(tp) \ 381 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp) 382 #define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \ 383 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \ 384 __NLA_IS_SINT_TYPE(tp) || \ 385 tp == NLA_MSECS || \ 386 tp == NLA_BINARY) + tp) 387 #define NLA_ENSURE_NO_VALIDATION_PTR(tp) \ 388 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \ 389 tp != NLA_REJECT && \ 390 tp != NLA_NESTED && \ 391 tp != NLA_NESTED_ARRAY) + tp) 392 393 #define NLA_POLICY_RANGE(tp, _min, _max) { \ 394 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 395 .validation_type = NLA_VALIDATE_RANGE, \ 396 .min = _min, \ 397 .max = _max \ 398 } 399 400 #define NLA_POLICY_FULL_RANGE(tp, _range) { \ 401 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \ 402 .validation_type = NLA_VALIDATE_RANGE_PTR, \ 403 .range = _range, \ 404 } 405 406 #define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \ 407 .type = NLA_ENSURE_SINT_TYPE(tp), \ 408 .validation_type = NLA_VALIDATE_RANGE_PTR, \ 409 .range_signed = _range, \ 410 } 411 412 #define NLA_POLICY_MIN(tp, _min) { \ 413 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 414 .validation_type = NLA_VALIDATE_MIN, \ 415 .min = _min, \ 416 } 417 418 #define NLA_POLICY_MAX(tp, _max) { \ 419 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 420 .validation_type = NLA_VALIDATE_MAX, \ 421 .max = _max, \ 422 .network_byte_order = 0, \ 423 } 424 425 #define NLA_POLICY_MAX_BE(tp, _max) { \ 426 .type = NLA_ENSURE_UINT_TYPE(tp), \ 427 .validation_type = NLA_VALIDATE_MAX, \ 428 .max = _max, \ 429 .network_byte_order = 1, \ 430 } 431 432 #define NLA_POLICY_MASK(tp, _mask) { \ 433 .type = NLA_ENSURE_UINT_TYPE(tp), \ 434 .validation_type = NLA_VALIDATE_MASK, \ 435 .mask = _mask, \ 436 } 437 438 #define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \ 439 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \ 440 .validation_type = NLA_VALIDATE_FUNCTION, \ 441 .validate = fn, \ 442 .len = __VA_ARGS__ + 0, \ 443 } 444 445 #define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len) 446 #define NLA_POLICY_EXACT_LEN_WARN(_len) { \ 447 .type = NLA_BINARY, \ 448 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \ 449 .min = _len, \ 450 .max = _len \ 451 } 452 #define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len) 453 454 /** 455 * struct nl_info - netlink source information 456 * @nlh: Netlink message header of original request 457 * @nl_net: Network namespace 458 * @portid: Netlink PORTID of requesting application 459 * @skip_notify: Skip netlink notifications to user space 460 * @skip_notify_kernel: Skip selected in-kernel notifications 461 */ 462 struct nl_info { 463 struct nlmsghdr *nlh; 464 struct net *nl_net; 465 u32 portid; 466 u8 skip_notify:1, 467 skip_notify_kernel:1; 468 }; 469 470 /** 471 * enum netlink_validation - netlink message/attribute validation levels 472 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about 473 * extra data at the end of the message, attributes being longer than 474 * they should be, or unknown attributes being present. 475 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing. 476 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING 477 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict(). 478 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy. 479 * This can safely be set by the kernel when the given policy has no 480 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries 481 * are enforced going forward. 482 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g. 483 * U8, U16, U32 must have exact size, etc.) 484 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY) 485 * and unset for other policies. 486 */ 487 enum netlink_validation { 488 NL_VALIDATE_LIBERAL = 0, 489 NL_VALIDATE_TRAILING = BIT(0), 490 NL_VALIDATE_MAXTYPE = BIT(1), 491 NL_VALIDATE_UNSPEC = BIT(2), 492 NL_VALIDATE_STRICT_ATTRS = BIT(3), 493 NL_VALIDATE_NESTED = BIT(4), 494 }; 495 496 #define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\ 497 NL_VALIDATE_MAXTYPE) 498 #define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\ 499 NL_VALIDATE_MAXTYPE |\ 500 NL_VALIDATE_UNSPEC |\ 501 NL_VALIDATE_STRICT_ATTRS |\ 502 NL_VALIDATE_NESTED) 503 504 int netlink_rcv_skb(struct sk_buff *skb, 505 int (*cb)(struct sk_buff *, struct nlmsghdr *, 506 struct netlink_ext_ack *)); 507 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, 508 unsigned int group, int report, gfp_t flags); 509 510 int __nla_validate(const struct nlattr *head, int len, int maxtype, 511 const struct nla_policy *policy, unsigned int validate, 512 struct netlink_ext_ack *extack); 513 int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, 514 int len, const struct nla_policy *policy, unsigned int validate, 515 struct netlink_ext_ack *extack); 516 int nla_policy_len(const struct nla_policy *, int); 517 struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype); 518 ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize); 519 char *nla_strdup(const struct nlattr *nla, gfp_t flags); 520 int nla_memcpy(void *dest, const struct nlattr *src, int count); 521 int nla_memcmp(const struct nlattr *nla, const void *data, size_t size); 522 int nla_strcmp(const struct nlattr *nla, const char *str); 523 struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 524 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, 525 int attrlen, int padattr); 526 void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 527 struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 528 struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, 529 int attrlen, int padattr); 530 void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 531 void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, 532 const void *data); 533 void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 534 const void *data, int padattr); 535 void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 536 int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); 537 int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 538 const void *data, int padattr); 539 int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 540 int nla_append(struct sk_buff *skb, int attrlen, const void *data); 541 542 /************************************************************************** 543 * Netlink Messages 544 **************************************************************************/ 545 546 /** 547 * nlmsg_msg_size - length of netlink message not including padding 548 * @payload: length of message payload 549 */ 550 static inline int nlmsg_msg_size(int payload) 551 { 552 return NLMSG_HDRLEN + payload; 553 } 554 555 /** 556 * nlmsg_total_size - length of netlink message including padding 557 * @payload: length of message payload 558 */ 559 static inline int nlmsg_total_size(int payload) 560 { 561 return NLMSG_ALIGN(nlmsg_msg_size(payload)); 562 } 563 564 /** 565 * nlmsg_padlen - length of padding at the message's tail 566 * @payload: length of message payload 567 */ 568 static inline int nlmsg_padlen(int payload) 569 { 570 return nlmsg_total_size(payload) - nlmsg_msg_size(payload); 571 } 572 573 /** 574 * nlmsg_data - head of message payload 575 * @nlh: netlink message header 576 */ 577 static inline void *nlmsg_data(const struct nlmsghdr *nlh) 578 { 579 return (unsigned char *) nlh + NLMSG_HDRLEN; 580 } 581 582 /** 583 * nlmsg_len - length of message payload 584 * @nlh: netlink message header 585 */ 586 static inline int nlmsg_len(const struct nlmsghdr *nlh) 587 { 588 return nlh->nlmsg_len - NLMSG_HDRLEN; 589 } 590 591 /** 592 * nlmsg_attrdata - head of attributes data 593 * @nlh: netlink message header 594 * @hdrlen: length of family specific header 595 */ 596 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 597 int hdrlen) 598 { 599 unsigned char *data = nlmsg_data(nlh); 600 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); 601 } 602 603 /** 604 * nlmsg_attrlen - length of attributes data 605 * @nlh: netlink message header 606 * @hdrlen: length of family specific header 607 */ 608 static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) 609 { 610 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); 611 } 612 613 /** 614 * nlmsg_ok - check if the netlink message fits into the remaining bytes 615 * @nlh: netlink message header 616 * @remaining: number of bytes remaining in message stream 617 */ 618 static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) 619 { 620 return (remaining >= (int) sizeof(struct nlmsghdr) && 621 nlh->nlmsg_len >= sizeof(struct nlmsghdr) && 622 nlh->nlmsg_len <= remaining); 623 } 624 625 /** 626 * nlmsg_next - next netlink message in message stream 627 * @nlh: netlink message header 628 * @remaining: number of bytes remaining in message stream 629 * 630 * Returns the next netlink message in the message stream and 631 * decrements remaining by the size of the current message. 632 */ 633 static inline struct nlmsghdr * 634 nlmsg_next(const struct nlmsghdr *nlh, int *remaining) 635 { 636 int totlen = NLMSG_ALIGN(nlh->nlmsg_len); 637 638 *remaining -= totlen; 639 640 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); 641 } 642 643 /** 644 * nla_parse - Parse a stream of attributes into a tb buffer 645 * @tb: destination array with maxtype+1 elements 646 * @maxtype: maximum attribute type to be expected 647 * @head: head of attribute stream 648 * @len: length of attribute stream 649 * @policy: validation policy 650 * @extack: extended ACK pointer 651 * 652 * Parses a stream of attributes and stores a pointer to each attribute in 653 * the tb array accessible via the attribute type. Attributes with a type 654 * exceeding maxtype will be rejected, policy must be specified, attributes 655 * will be validated in the strictest way possible. 656 * 657 * Returns 0 on success or a negative error code. 658 */ 659 static inline int nla_parse(struct nlattr **tb, int maxtype, 660 const struct nlattr *head, int len, 661 const struct nla_policy *policy, 662 struct netlink_ext_ack *extack) 663 { 664 return __nla_parse(tb, maxtype, head, len, policy, 665 NL_VALIDATE_STRICT, extack); 666 } 667 668 /** 669 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer 670 * @tb: destination array with maxtype+1 elements 671 * @maxtype: maximum attribute type to be expected 672 * @head: head of attribute stream 673 * @len: length of attribute stream 674 * @policy: validation policy 675 * @extack: extended ACK pointer 676 * 677 * Parses a stream of attributes and stores a pointer to each attribute in 678 * the tb array accessible via the attribute type. Attributes with a type 679 * exceeding maxtype will be ignored and attributes from the policy are not 680 * always strictly validated (only for new attributes). 681 * 682 * Returns 0 on success or a negative error code. 683 */ 684 static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype, 685 const struct nlattr *head, int len, 686 const struct nla_policy *policy, 687 struct netlink_ext_ack *extack) 688 { 689 return __nla_parse(tb, maxtype, head, len, policy, 690 NL_VALIDATE_LIBERAL, extack); 691 } 692 693 /** 694 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer 695 * @tb: destination array with maxtype+1 elements 696 * @maxtype: maximum attribute type to be expected 697 * @head: head of attribute stream 698 * @len: length of attribute stream 699 * @policy: validation policy 700 * @extack: extended ACK pointer 701 * 702 * Parses a stream of attributes and stores a pointer to each attribute in 703 * the tb array accessible via the attribute type. Attributes with a type 704 * exceeding maxtype will be rejected as well as trailing data, but the 705 * policy is not completely strictly validated (only for new attributes). 706 * 707 * Returns 0 on success or a negative error code. 708 */ 709 static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype, 710 const struct nlattr *head, 711 int len, 712 const struct nla_policy *policy, 713 struct netlink_ext_ack *extack) 714 { 715 return __nla_parse(tb, maxtype, head, len, policy, 716 NL_VALIDATE_DEPRECATED_STRICT, extack); 717 } 718 719 /** 720 * __nlmsg_parse - parse attributes of a netlink message 721 * @nlh: netlink message header 722 * @hdrlen: length of family specific header 723 * @tb: destination array with maxtype+1 elements 724 * @maxtype: maximum attribute type to be expected 725 * @policy: validation policy 726 * @validate: validation strictness 727 * @extack: extended ACK report struct 728 * 729 * See nla_parse() 730 */ 731 static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 732 struct nlattr *tb[], int maxtype, 733 const struct nla_policy *policy, 734 unsigned int validate, 735 struct netlink_ext_ack *extack) 736 { 737 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) { 738 NL_SET_ERR_MSG(extack, "Invalid header length"); 739 return -EINVAL; 740 } 741 742 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 743 nlmsg_attrlen(nlh, hdrlen), policy, validate, 744 extack); 745 } 746 747 /** 748 * nlmsg_parse - parse attributes of a netlink message 749 * @nlh: netlink message header 750 * @hdrlen: length of family specific header 751 * @tb: destination array with maxtype+1 elements 752 * @maxtype: maximum attribute type to be expected 753 * @policy: validation policy 754 * @extack: extended ACK report struct 755 * 756 * See nla_parse() 757 */ 758 static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 759 struct nlattr *tb[], int maxtype, 760 const struct nla_policy *policy, 761 struct netlink_ext_ack *extack) 762 { 763 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 764 NL_VALIDATE_STRICT, extack); 765 } 766 767 /** 768 * nlmsg_parse_deprecated - parse attributes of a netlink message 769 * @nlh: netlink message header 770 * @hdrlen: length of family specific header 771 * @tb: destination array with maxtype+1 elements 772 * @maxtype: maximum attribute type to be expected 773 * @policy: validation policy 774 * @extack: extended ACK report struct 775 * 776 * See nla_parse_deprecated() 777 */ 778 static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen, 779 struct nlattr *tb[], int maxtype, 780 const struct nla_policy *policy, 781 struct netlink_ext_ack *extack) 782 { 783 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 784 NL_VALIDATE_LIBERAL, extack); 785 } 786 787 /** 788 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message 789 * @nlh: netlink message header 790 * @hdrlen: length of family specific header 791 * @tb: destination array with maxtype+1 elements 792 * @maxtype: maximum attribute type to be expected 793 * @policy: validation policy 794 * @extack: extended ACK report struct 795 * 796 * See nla_parse_deprecated_strict() 797 */ 798 static inline int 799 nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen, 800 struct nlattr *tb[], int maxtype, 801 const struct nla_policy *policy, 802 struct netlink_ext_ack *extack) 803 { 804 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 805 NL_VALIDATE_DEPRECATED_STRICT, extack); 806 } 807 808 /** 809 * nlmsg_find_attr - find a specific attribute in a netlink message 810 * @nlh: netlink message header 811 * @hdrlen: length of familiy specific header 812 * @attrtype: type of attribute to look for 813 * 814 * Returns the first attribute which matches the specified type. 815 */ 816 static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh, 817 int hdrlen, int attrtype) 818 { 819 return nla_find(nlmsg_attrdata(nlh, hdrlen), 820 nlmsg_attrlen(nlh, hdrlen), attrtype); 821 } 822 823 /** 824 * nla_validate_deprecated - Validate a stream of attributes 825 * @head: head of attribute stream 826 * @len: length of attribute stream 827 * @maxtype: maximum attribute type to be expected 828 * @policy: validation policy 829 * @extack: extended ACK report struct 830 * 831 * Validates all attributes in the specified attribute stream against the 832 * specified policy. Validation is done in liberal mode. 833 * See documenation of struct nla_policy for more details. 834 * 835 * Returns 0 on success or a negative error code. 836 */ 837 static inline int nla_validate_deprecated(const struct nlattr *head, int len, 838 int maxtype, 839 const struct nla_policy *policy, 840 struct netlink_ext_ack *extack) 841 { 842 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL, 843 extack); 844 } 845 846 /** 847 * nla_validate - Validate a stream of attributes 848 * @head: head of attribute stream 849 * @len: length of attribute stream 850 * @maxtype: maximum attribute type to be expected 851 * @policy: validation policy 852 * @extack: extended ACK report struct 853 * 854 * Validates all attributes in the specified attribute stream against the 855 * specified policy. Validation is done in strict mode. 856 * See documenation of struct nla_policy for more details. 857 * 858 * Returns 0 on success or a negative error code. 859 */ 860 static inline int nla_validate(const struct nlattr *head, int len, int maxtype, 861 const struct nla_policy *policy, 862 struct netlink_ext_ack *extack) 863 { 864 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT, 865 extack); 866 } 867 868 /** 869 * nlmsg_validate_deprecated - validate a netlink message including attributes 870 * @nlh: netlinket message header 871 * @hdrlen: length of familiy specific header 872 * @maxtype: maximum attribute type to be expected 873 * @policy: validation policy 874 * @extack: extended ACK report struct 875 */ 876 static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh, 877 int hdrlen, int maxtype, 878 const struct nla_policy *policy, 879 struct netlink_ext_ack *extack) 880 { 881 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 882 return -EINVAL; 883 884 return __nla_validate(nlmsg_attrdata(nlh, hdrlen), 885 nlmsg_attrlen(nlh, hdrlen), maxtype, 886 policy, NL_VALIDATE_LIBERAL, extack); 887 } 888 889 890 891 /** 892 * nlmsg_report - need to report back to application? 893 * @nlh: netlink message header 894 * 895 * Returns 1 if a report back to the application is requested. 896 */ 897 static inline int nlmsg_report(const struct nlmsghdr *nlh) 898 { 899 return nlh ? !!(nlh->nlmsg_flags & NLM_F_ECHO) : 0; 900 } 901 902 /** 903 * nlmsg_seq - return the seq number of netlink message 904 * @nlh: netlink message header 905 * 906 * Returns 0 if netlink message is NULL 907 */ 908 static inline u32 nlmsg_seq(const struct nlmsghdr *nlh) 909 { 910 return nlh ? nlh->nlmsg_seq : 0; 911 } 912 913 /** 914 * nlmsg_for_each_attr - iterate over a stream of attributes 915 * @pos: loop counter, set to current attribute 916 * @nlh: netlink message header 917 * @hdrlen: length of familiy specific header 918 * @rem: initialized to len, holds bytes currently remaining in stream 919 */ 920 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ 921 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ 922 nlmsg_attrlen(nlh, hdrlen), rem) 923 924 /** 925 * nlmsg_put - Add a new netlink message to an skb 926 * @skb: socket buffer to store message in 927 * @portid: netlink PORTID of requesting application 928 * @seq: sequence number of message 929 * @type: message type 930 * @payload: length of message payload 931 * @flags: message flags 932 * 933 * Returns NULL if the tailroom of the skb is insufficient to store 934 * the message header and payload. 935 */ 936 static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, 937 int type, int payload, int flags) 938 { 939 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) 940 return NULL; 941 942 return __nlmsg_put(skb, portid, seq, type, payload, flags); 943 } 944 945 /** 946 * nlmsg_append - Add more data to a nlmsg in a skb 947 * @skb: socket buffer to store message in 948 * @size: length of message payload 949 * 950 * Append data to an existing nlmsg, used when constructing a message 951 * with multiple fixed-format headers (which is rare). 952 * Returns NULL if the tailroom of the skb is insufficient to store 953 * the extra payload. 954 */ 955 static inline void *nlmsg_append(struct sk_buff *skb, u32 size) 956 { 957 if (unlikely(skb_tailroom(skb) < NLMSG_ALIGN(size))) 958 return NULL; 959 960 if (NLMSG_ALIGN(size) - size) 961 memset(skb_tail_pointer(skb) + size, 0, 962 NLMSG_ALIGN(size) - size); 963 return __skb_put(skb, NLMSG_ALIGN(size)); 964 } 965 966 /** 967 * nlmsg_put_answer - Add a new callback based netlink message to an skb 968 * @skb: socket buffer to store message in 969 * @cb: netlink callback 970 * @type: message type 971 * @payload: length of message payload 972 * @flags: message flags 973 * 974 * Returns NULL if the tailroom of the skb is insufficient to store 975 * the message header and payload. 976 */ 977 static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, 978 struct netlink_callback *cb, 979 int type, int payload, 980 int flags) 981 { 982 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 983 type, payload, flags); 984 } 985 986 /** 987 * nlmsg_new - Allocate a new netlink message 988 * @payload: size of the message payload 989 * @flags: the type of memory to allocate. 990 * 991 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known 992 * and a good default is needed. 993 */ 994 static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) 995 { 996 return alloc_skb(nlmsg_total_size(payload), flags); 997 } 998 999 /** 1000 * nlmsg_end - Finalize a netlink message 1001 * @skb: socket buffer the message is stored in 1002 * @nlh: netlink message header 1003 * 1004 * Corrects the netlink message header to include the appeneded 1005 * attributes. Only necessary if attributes have been added to 1006 * the message. 1007 */ 1008 static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 1009 { 1010 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 1011 } 1012 1013 /** 1014 * nlmsg_get_pos - return current position in netlink message 1015 * @skb: socket buffer the message is stored in 1016 * 1017 * Returns a pointer to the current tail of the message. 1018 */ 1019 static inline void *nlmsg_get_pos(struct sk_buff *skb) 1020 { 1021 return skb_tail_pointer(skb); 1022 } 1023 1024 /** 1025 * nlmsg_trim - Trim message to a mark 1026 * @skb: socket buffer the message is stored in 1027 * @mark: mark to trim to 1028 * 1029 * Trims the message to the provided mark. 1030 */ 1031 static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 1032 { 1033 if (mark) { 1034 WARN_ON((unsigned char *) mark < skb->data); 1035 skb_trim(skb, (unsigned char *) mark - skb->data); 1036 } 1037 } 1038 1039 /** 1040 * nlmsg_cancel - Cancel construction of a netlink message 1041 * @skb: socket buffer the message is stored in 1042 * @nlh: netlink message header 1043 * 1044 * Removes the complete netlink message including all 1045 * attributes from the socket buffer again. 1046 */ 1047 static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 1048 { 1049 nlmsg_trim(skb, nlh); 1050 } 1051 1052 /** 1053 * nlmsg_free - free a netlink message 1054 * @skb: socket buffer of netlink message 1055 */ 1056 static inline void nlmsg_free(struct sk_buff *skb) 1057 { 1058 kfree_skb(skb); 1059 } 1060 1061 /** 1062 * nlmsg_multicast - multicast a netlink message 1063 * @sk: netlink socket to spread messages to 1064 * @skb: netlink message as socket buffer 1065 * @portid: own netlink portid to avoid sending to yourself 1066 * @group: multicast group id 1067 * @flags: allocation flags 1068 */ 1069 static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 1070 u32 portid, unsigned int group, gfp_t flags) 1071 { 1072 int err; 1073 1074 NETLINK_CB(skb).dst_group = group; 1075 1076 err = netlink_broadcast(sk, skb, portid, group, flags); 1077 if (err > 0) 1078 err = 0; 1079 1080 return err; 1081 } 1082 1083 /** 1084 * nlmsg_unicast - unicast a netlink message 1085 * @sk: netlink socket to spread message to 1086 * @skb: netlink message as socket buffer 1087 * @portid: netlink portid of the destination socket 1088 */ 1089 static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid) 1090 { 1091 int err; 1092 1093 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT); 1094 if (err > 0) 1095 err = 0; 1096 1097 return err; 1098 } 1099 1100 /** 1101 * nlmsg_for_each_msg - iterate over a stream of messages 1102 * @pos: loop counter, set to current message 1103 * @head: head of message stream 1104 * @len: length of message stream 1105 * @rem: initialized to len, holds bytes currently remaining in stream 1106 */ 1107 #define nlmsg_for_each_msg(pos, head, len, rem) \ 1108 for (pos = head, rem = len; \ 1109 nlmsg_ok(pos, rem); \ 1110 pos = nlmsg_next(pos, &(rem))) 1111 1112 /** 1113 * nl_dump_check_consistent - check if sequence is consistent and advertise if not 1114 * @cb: netlink callback structure that stores the sequence number 1115 * @nlh: netlink message header to write the flag to 1116 * 1117 * This function checks if the sequence (generation) number changed during dump 1118 * and if it did, advertises it in the netlink message header. 1119 * 1120 * The correct way to use it is to set cb->seq to the generation counter when 1121 * all locks for dumping have been acquired, and then call this function for 1122 * each message that is generated. 1123 * 1124 * Note that due to initialisation concerns, 0 is an invalid sequence number 1125 * and must not be used by code that uses this functionality. 1126 */ 1127 static inline void 1128 nl_dump_check_consistent(struct netlink_callback *cb, 1129 struct nlmsghdr *nlh) 1130 { 1131 if (cb->prev_seq && cb->seq != cb->prev_seq) 1132 nlh->nlmsg_flags |= NLM_F_DUMP_INTR; 1133 cb->prev_seq = cb->seq; 1134 } 1135 1136 /************************************************************************** 1137 * Netlink Attributes 1138 **************************************************************************/ 1139 1140 /** 1141 * nla_attr_size - length of attribute not including padding 1142 * @payload: length of payload 1143 */ 1144 static inline int nla_attr_size(int payload) 1145 { 1146 return NLA_HDRLEN + payload; 1147 } 1148 1149 /** 1150 * nla_total_size - total length of attribute including padding 1151 * @payload: length of payload 1152 */ 1153 static inline int nla_total_size(int payload) 1154 { 1155 return NLA_ALIGN(nla_attr_size(payload)); 1156 } 1157 1158 /** 1159 * nla_padlen - length of padding at the tail of attribute 1160 * @payload: length of payload 1161 */ 1162 static inline int nla_padlen(int payload) 1163 { 1164 return nla_total_size(payload) - nla_attr_size(payload); 1165 } 1166 1167 /** 1168 * nla_type - attribute type 1169 * @nla: netlink attribute 1170 */ 1171 static inline int nla_type(const struct nlattr *nla) 1172 { 1173 return nla->nla_type & NLA_TYPE_MASK; 1174 } 1175 1176 /** 1177 * nla_data - head of payload 1178 * @nla: netlink attribute 1179 */ 1180 static inline void *nla_data(const struct nlattr *nla) 1181 { 1182 return (char *) nla + NLA_HDRLEN; 1183 } 1184 1185 /** 1186 * nla_len - length of payload 1187 * @nla: netlink attribute 1188 */ 1189 static inline int nla_len(const struct nlattr *nla) 1190 { 1191 return nla->nla_len - NLA_HDRLEN; 1192 } 1193 1194 /** 1195 * nla_ok - check if the netlink attribute fits into the remaining bytes 1196 * @nla: netlink attribute 1197 * @remaining: number of bytes remaining in attribute stream 1198 */ 1199 static inline int nla_ok(const struct nlattr *nla, int remaining) 1200 { 1201 return remaining >= (int) sizeof(*nla) && 1202 nla->nla_len >= sizeof(*nla) && 1203 nla->nla_len <= remaining; 1204 } 1205 1206 /** 1207 * nla_next - next netlink attribute in attribute stream 1208 * @nla: netlink attribute 1209 * @remaining: number of bytes remaining in attribute stream 1210 * 1211 * Returns the next netlink attribute in the attribute stream and 1212 * decrements remaining by the size of the current attribute. 1213 */ 1214 static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 1215 { 1216 unsigned int totlen = NLA_ALIGN(nla->nla_len); 1217 1218 *remaining -= totlen; 1219 return (struct nlattr *) ((char *) nla + totlen); 1220 } 1221 1222 /** 1223 * nla_find_nested - find attribute in a set of nested attributes 1224 * @nla: attribute containing the nested attributes 1225 * @attrtype: type of attribute to look for 1226 * 1227 * Returns the first attribute which matches the specified type. 1228 */ 1229 static inline struct nlattr * 1230 nla_find_nested(const struct nlattr *nla, int attrtype) 1231 { 1232 return nla_find(nla_data(nla), nla_len(nla), attrtype); 1233 } 1234 1235 /** 1236 * nla_parse_nested - parse nested attributes 1237 * @tb: destination array with maxtype+1 elements 1238 * @maxtype: maximum attribute type to be expected 1239 * @nla: attribute containing the nested attributes 1240 * @policy: validation policy 1241 * @extack: extended ACK report struct 1242 * 1243 * See nla_parse() 1244 */ 1245 static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 1246 const struct nlattr *nla, 1247 const struct nla_policy *policy, 1248 struct netlink_ext_ack *extack) 1249 { 1250 if (!(nla->nla_type & NLA_F_NESTED)) { 1251 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing"); 1252 return -EINVAL; 1253 } 1254 1255 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, 1256 NL_VALIDATE_STRICT, extack); 1257 } 1258 1259 /** 1260 * nla_parse_nested_deprecated - parse nested attributes 1261 * @tb: destination array with maxtype+1 elements 1262 * @maxtype: maximum attribute type to be expected 1263 * @nla: attribute containing the nested attributes 1264 * @policy: validation policy 1265 * @extack: extended ACK report struct 1266 * 1267 * See nla_parse_deprecated() 1268 */ 1269 static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype, 1270 const struct nlattr *nla, 1271 const struct nla_policy *policy, 1272 struct netlink_ext_ack *extack) 1273 { 1274 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, 1275 NL_VALIDATE_LIBERAL, extack); 1276 } 1277 1278 /** 1279 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 1280 * @skb: socket buffer to add attribute to 1281 * @attrtype: attribute type 1282 * @value: numeric value 1283 */ 1284 static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 1285 { 1286 /* temporary variables to work around GCC PR81715 with asan-stack=1 */ 1287 u8 tmp = value; 1288 1289 return nla_put(skb, attrtype, sizeof(u8), &tmp); 1290 } 1291 1292 /** 1293 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer 1294 * @skb: socket buffer to add attribute to 1295 * @attrtype: attribute type 1296 * @value: numeric value 1297 */ 1298 static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) 1299 { 1300 u16 tmp = value; 1301 1302 return nla_put(skb, attrtype, sizeof(u16), &tmp); 1303 } 1304 1305 /** 1306 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer 1307 * @skb: socket buffer to add attribute to 1308 * @attrtype: attribute type 1309 * @value: numeric value 1310 */ 1311 static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value) 1312 { 1313 __be16 tmp = value; 1314 1315 return nla_put(skb, attrtype, sizeof(__be16), &tmp); 1316 } 1317 1318 /** 1319 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer 1320 * @skb: socket buffer to add attribute to 1321 * @attrtype: attribute type 1322 * @value: numeric value 1323 */ 1324 static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value) 1325 { 1326 __be16 tmp = value; 1327 1328 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 1329 } 1330 1331 /** 1332 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer 1333 * @skb: socket buffer to add attribute to 1334 * @attrtype: attribute type 1335 * @value: numeric value 1336 */ 1337 static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value) 1338 { 1339 __le16 tmp = value; 1340 1341 return nla_put(skb, attrtype, sizeof(__le16), &tmp); 1342 } 1343 1344 /** 1345 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 1346 * @skb: socket buffer to add attribute to 1347 * @attrtype: attribute type 1348 * @value: numeric value 1349 */ 1350 static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 1351 { 1352 u32 tmp = value; 1353 1354 return nla_put(skb, attrtype, sizeof(u32), &tmp); 1355 } 1356 1357 /** 1358 * nla_put_be32 - Add a __be32 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_be32(struct sk_buff *skb, int attrtype, __be32 value) 1364 { 1365 __be32 tmp = value; 1366 1367 return nla_put(skb, attrtype, sizeof(__be32), &tmp); 1368 } 1369 1370 /** 1371 * nla_put_net32 - Add 32-bit network byte order 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_net32(struct sk_buff *skb, int attrtype, __be32 value) 1377 { 1378 __be32 tmp = value; 1379 1380 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 1381 } 1382 1383 /** 1384 * nla_put_le32 - Add a __le32 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_le32(struct sk_buff *skb, int attrtype, __le32 value) 1390 { 1391 __le32 tmp = value; 1392 1393 return nla_put(skb, attrtype, sizeof(__le32), &tmp); 1394 } 1395 1396 /** 1397 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it 1398 * @skb: socket buffer to add attribute to 1399 * @attrtype: attribute type 1400 * @value: numeric value 1401 * @padattr: attribute type for the padding 1402 */ 1403 static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype, 1404 u64 value, int padattr) 1405 { 1406 u64 tmp = value; 1407 1408 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1409 } 1410 1411 /** 1412 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it 1413 * @skb: socket buffer to add attribute to 1414 * @attrtype: attribute type 1415 * @value: numeric value 1416 * @padattr: attribute type for the padding 1417 */ 1418 static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value, 1419 int padattr) 1420 { 1421 __be64 tmp = value; 1422 1423 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr); 1424 } 1425 1426 /** 1427 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it 1428 * @skb: socket buffer to add attribute to 1429 * @attrtype: attribute type 1430 * @value: numeric value 1431 * @padattr: attribute type for the padding 1432 */ 1433 static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value, 1434 int padattr) 1435 { 1436 __be64 tmp = value; 1437 1438 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp, 1439 padattr); 1440 } 1441 1442 /** 1443 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it 1444 * @skb: socket buffer to add attribute to 1445 * @attrtype: attribute type 1446 * @value: numeric value 1447 * @padattr: attribute type for the padding 1448 */ 1449 static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value, 1450 int padattr) 1451 { 1452 __le64 tmp = value; 1453 1454 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr); 1455 } 1456 1457 /** 1458 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer 1459 * @skb: socket buffer to add attribute to 1460 * @attrtype: attribute type 1461 * @value: numeric value 1462 */ 1463 static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value) 1464 { 1465 s8 tmp = value; 1466 1467 return nla_put(skb, attrtype, sizeof(s8), &tmp); 1468 } 1469 1470 /** 1471 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer 1472 * @skb: socket buffer to add attribute to 1473 * @attrtype: attribute type 1474 * @value: numeric value 1475 */ 1476 static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value) 1477 { 1478 s16 tmp = value; 1479 1480 return nla_put(skb, attrtype, sizeof(s16), &tmp); 1481 } 1482 1483 /** 1484 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer 1485 * @skb: socket buffer to add attribute to 1486 * @attrtype: attribute type 1487 * @value: numeric value 1488 */ 1489 static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value) 1490 { 1491 s32 tmp = value; 1492 1493 return nla_put(skb, attrtype, sizeof(s32), &tmp); 1494 } 1495 1496 /** 1497 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it 1498 * @skb: socket buffer to add attribute to 1499 * @attrtype: attribute type 1500 * @value: numeric value 1501 * @padattr: attribute type for the padding 1502 */ 1503 static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value, 1504 int padattr) 1505 { 1506 s64 tmp = value; 1507 1508 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr); 1509 } 1510 1511 /** 1512 * nla_put_string - Add a string netlink attribute to a socket buffer 1513 * @skb: socket buffer to add attribute to 1514 * @attrtype: attribute type 1515 * @str: NUL terminated string 1516 */ 1517 static inline int nla_put_string(struct sk_buff *skb, int attrtype, 1518 const char *str) 1519 { 1520 return nla_put(skb, attrtype, strlen(str) + 1, str); 1521 } 1522 1523 /** 1524 * nla_put_flag - Add a flag netlink attribute to a socket buffer 1525 * @skb: socket buffer to add attribute to 1526 * @attrtype: attribute type 1527 */ 1528 static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 1529 { 1530 return nla_put(skb, attrtype, 0, NULL); 1531 } 1532 1533 /** 1534 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it 1535 * @skb: socket buffer to add attribute to 1536 * @attrtype: attribute type 1537 * @njiffies: number of jiffies to convert to msecs 1538 * @padattr: attribute type for the padding 1539 */ 1540 static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 1541 unsigned long njiffies, int padattr) 1542 { 1543 u64 tmp = jiffies_to_msecs(njiffies); 1544 1545 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1546 } 1547 1548 /** 1549 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket 1550 * buffer 1551 * @skb: socket buffer to add attribute to 1552 * @attrtype: attribute type 1553 * @addr: IPv4 address 1554 */ 1555 static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype, 1556 __be32 addr) 1557 { 1558 __be32 tmp = addr; 1559 1560 return nla_put_be32(skb, attrtype, tmp); 1561 } 1562 1563 /** 1564 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket 1565 * buffer 1566 * @skb: socket buffer to add attribute to 1567 * @attrtype: attribute type 1568 * @addr: IPv6 address 1569 */ 1570 static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype, 1571 const struct in6_addr *addr) 1572 { 1573 return nla_put(skb, attrtype, sizeof(*addr), addr); 1574 } 1575 1576 /** 1577 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer 1578 * @skb: socket buffer to add attribute to 1579 * @attrtype: attribute type 1580 * @value: value carrying bits 1581 * @selector: selector of valid bits 1582 */ 1583 static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype, 1584 __u32 value, __u32 selector) 1585 { 1586 struct nla_bitfield32 tmp = { value, selector, }; 1587 1588 return nla_put(skb, attrtype, sizeof(tmp), &tmp); 1589 } 1590 1591 /** 1592 * nla_get_u32 - return payload of u32 attribute 1593 * @nla: u32 netlink attribute 1594 */ 1595 static inline u32 nla_get_u32(const struct nlattr *nla) 1596 { 1597 return *(u32 *) nla_data(nla); 1598 } 1599 1600 /** 1601 * nla_get_be32 - return payload of __be32 attribute 1602 * @nla: __be32 netlink attribute 1603 */ 1604 static inline __be32 nla_get_be32(const struct nlattr *nla) 1605 { 1606 return *(__be32 *) nla_data(nla); 1607 } 1608 1609 /** 1610 * nla_get_le32 - return payload of __le32 attribute 1611 * @nla: __le32 netlink attribute 1612 */ 1613 static inline __le32 nla_get_le32(const struct nlattr *nla) 1614 { 1615 return *(__le32 *) nla_data(nla); 1616 } 1617 1618 /** 1619 * nla_get_u16 - return payload of u16 attribute 1620 * @nla: u16 netlink attribute 1621 */ 1622 static inline u16 nla_get_u16(const struct nlattr *nla) 1623 { 1624 return *(u16 *) nla_data(nla); 1625 } 1626 1627 /** 1628 * nla_get_be16 - return payload of __be16 attribute 1629 * @nla: __be16 netlink attribute 1630 */ 1631 static inline __be16 nla_get_be16(const struct nlattr *nla) 1632 { 1633 return *(__be16 *) nla_data(nla); 1634 } 1635 1636 /** 1637 * nla_get_le16 - return payload of __le16 attribute 1638 * @nla: __le16 netlink attribute 1639 */ 1640 static inline __le16 nla_get_le16(const struct nlattr *nla) 1641 { 1642 return *(__le16 *) nla_data(nla); 1643 } 1644 1645 /** 1646 * nla_get_u8 - return payload of u8 attribute 1647 * @nla: u8 netlink attribute 1648 */ 1649 static inline u8 nla_get_u8(const struct nlattr *nla) 1650 { 1651 return *(u8 *) nla_data(nla); 1652 } 1653 1654 /** 1655 * nla_get_u64 - return payload of u64 attribute 1656 * @nla: u64 netlink attribute 1657 */ 1658 static inline u64 nla_get_u64(const struct nlattr *nla) 1659 { 1660 u64 tmp; 1661 1662 nla_memcpy(&tmp, nla, sizeof(tmp)); 1663 1664 return tmp; 1665 } 1666 1667 /** 1668 * nla_get_be64 - return payload of __be64 attribute 1669 * @nla: __be64 netlink attribute 1670 */ 1671 static inline __be64 nla_get_be64(const struct nlattr *nla) 1672 { 1673 __be64 tmp; 1674 1675 nla_memcpy(&tmp, nla, sizeof(tmp)); 1676 1677 return tmp; 1678 } 1679 1680 /** 1681 * nla_get_le64 - return payload of __le64 attribute 1682 * @nla: __le64 netlink attribute 1683 */ 1684 static inline __le64 nla_get_le64(const struct nlattr *nla) 1685 { 1686 return *(__le64 *) nla_data(nla); 1687 } 1688 1689 /** 1690 * nla_get_s32 - return payload of s32 attribute 1691 * @nla: s32 netlink attribute 1692 */ 1693 static inline s32 nla_get_s32(const struct nlattr *nla) 1694 { 1695 return *(s32 *) nla_data(nla); 1696 } 1697 1698 /** 1699 * nla_get_s16 - return payload of s16 attribute 1700 * @nla: s16 netlink attribute 1701 */ 1702 static inline s16 nla_get_s16(const struct nlattr *nla) 1703 { 1704 return *(s16 *) nla_data(nla); 1705 } 1706 1707 /** 1708 * nla_get_s8 - return payload of s8 attribute 1709 * @nla: s8 netlink attribute 1710 */ 1711 static inline s8 nla_get_s8(const struct nlattr *nla) 1712 { 1713 return *(s8 *) nla_data(nla); 1714 } 1715 1716 /** 1717 * nla_get_s64 - return payload of s64 attribute 1718 * @nla: s64 netlink attribute 1719 */ 1720 static inline s64 nla_get_s64(const struct nlattr *nla) 1721 { 1722 s64 tmp; 1723 1724 nla_memcpy(&tmp, nla, sizeof(tmp)); 1725 1726 return tmp; 1727 } 1728 1729 /** 1730 * nla_get_flag - return payload of flag attribute 1731 * @nla: flag netlink attribute 1732 */ 1733 static inline int nla_get_flag(const struct nlattr *nla) 1734 { 1735 return !!nla; 1736 } 1737 1738 /** 1739 * nla_get_msecs - return payload of msecs attribute 1740 * @nla: msecs netlink attribute 1741 * 1742 * Returns the number of milliseconds in jiffies. 1743 */ 1744 static inline unsigned long nla_get_msecs(const struct nlattr *nla) 1745 { 1746 u64 msecs = nla_get_u64(nla); 1747 1748 return msecs_to_jiffies((unsigned long) msecs); 1749 } 1750 1751 /** 1752 * nla_get_in_addr - return payload of IPv4 address attribute 1753 * @nla: IPv4 address netlink attribute 1754 */ 1755 static inline __be32 nla_get_in_addr(const struct nlattr *nla) 1756 { 1757 return *(__be32 *) nla_data(nla); 1758 } 1759 1760 /** 1761 * nla_get_in6_addr - return payload of IPv6 address attribute 1762 * @nla: IPv6 address netlink attribute 1763 */ 1764 static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla) 1765 { 1766 struct in6_addr tmp; 1767 1768 nla_memcpy(&tmp, nla, sizeof(tmp)); 1769 return tmp; 1770 } 1771 1772 /** 1773 * nla_get_bitfield32 - return payload of 32 bitfield attribute 1774 * @nla: nla_bitfield32 attribute 1775 */ 1776 static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla) 1777 { 1778 struct nla_bitfield32 tmp; 1779 1780 nla_memcpy(&tmp, nla, sizeof(tmp)); 1781 return tmp; 1782 } 1783 1784 /** 1785 * nla_memdup - duplicate attribute memory (kmemdup) 1786 * @src: netlink attribute to duplicate from 1787 * @gfp: GFP mask 1788 */ 1789 static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp) 1790 { 1791 return kmemdup(nla_data(src), nla_len(src), gfp); 1792 } 1793 1794 /** 1795 * nla_nest_start_noflag - Start a new level of nested attributes 1796 * @skb: socket buffer to add attributes to 1797 * @attrtype: attribute type of container 1798 * 1799 * This function exists for backward compatibility to use in APIs which never 1800 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use 1801 * nla_nest_start() which sets the flag. 1802 * 1803 * Returns the container attribute or NULL on error 1804 */ 1805 static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb, 1806 int attrtype) 1807 { 1808 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 1809 1810 if (nla_put(skb, attrtype, 0, NULL) < 0) 1811 return NULL; 1812 1813 return start; 1814 } 1815 1816 /** 1817 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED 1818 * @skb: socket buffer to add attributes to 1819 * @attrtype: attribute type of container 1820 * 1821 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED 1822 * flag. This is the preferred function to use in new code. 1823 * 1824 * Returns the container attribute or NULL on error 1825 */ 1826 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 1827 { 1828 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED); 1829 } 1830 1831 /** 1832 * nla_nest_end - Finalize nesting of attributes 1833 * @skb: socket buffer the attributes are stored in 1834 * @start: container attribute 1835 * 1836 * Corrects the container attribute header to include the all 1837 * appeneded attributes. 1838 * 1839 * Returns the total data length of the skb. 1840 */ 1841 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 1842 { 1843 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1844 return skb->len; 1845 } 1846 1847 /** 1848 * nla_nest_cancel - Cancel nesting of attributes 1849 * @skb: socket buffer the message is stored in 1850 * @start: container attribute 1851 * 1852 * Removes the container attribute and including all nested 1853 * attributes. Returns -EMSGSIZE 1854 */ 1855 static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 1856 { 1857 nlmsg_trim(skb, start); 1858 } 1859 1860 /** 1861 * __nla_validate_nested - Validate a stream of nested attributes 1862 * @start: container attribute 1863 * @maxtype: maximum attribute type to be expected 1864 * @policy: validation policy 1865 * @validate: validation strictness 1866 * @extack: extended ACK report struct 1867 * 1868 * Validates all attributes in the nested attribute stream against the 1869 * specified policy. Attributes with a type exceeding maxtype will be 1870 * ignored. See documenation of struct nla_policy for more details. 1871 * 1872 * Returns 0 on success or a negative error code. 1873 */ 1874 static inline int __nla_validate_nested(const struct nlattr *start, int maxtype, 1875 const struct nla_policy *policy, 1876 unsigned int validate, 1877 struct netlink_ext_ack *extack) 1878 { 1879 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy, 1880 validate, extack); 1881 } 1882 1883 static inline int 1884 nla_validate_nested(const struct nlattr *start, int maxtype, 1885 const struct nla_policy *policy, 1886 struct netlink_ext_ack *extack) 1887 { 1888 return __nla_validate_nested(start, maxtype, policy, 1889 NL_VALIDATE_STRICT, extack); 1890 } 1891 1892 static inline int 1893 nla_validate_nested_deprecated(const struct nlattr *start, int maxtype, 1894 const struct nla_policy *policy, 1895 struct netlink_ext_ack *extack) 1896 { 1897 return __nla_validate_nested(start, maxtype, policy, 1898 NL_VALIDATE_LIBERAL, extack); 1899 } 1900 1901 /** 1902 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute 1903 * @skb: socket buffer the message is stored in 1904 * 1905 * Return true if padding is needed to align the next attribute (nla_data()) to 1906 * a 64-bit aligned area. 1907 */ 1908 static inline bool nla_need_padding_for_64bit(struct sk_buff *skb) 1909 { 1910 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 1911 /* The nlattr header is 4 bytes in size, that's why we test 1912 * if the skb->data _is_ aligned. A NOP attribute, plus 1913 * nlattr header for next attribute, will make nla_data() 1914 * 8-byte aligned. 1915 */ 1916 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8)) 1917 return true; 1918 #endif 1919 return false; 1920 } 1921 1922 /** 1923 * nla_align_64bit - 64-bit align the nla_data() of next attribute 1924 * @skb: socket buffer the message is stored in 1925 * @padattr: attribute type for the padding 1926 * 1927 * Conditionally emit a padding netlink attribute in order to make 1928 * the next attribute we emit have a 64-bit aligned nla_data() area. 1929 * This will only be done in architectures which do not have 1930 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined. 1931 * 1932 * Returns zero on success or a negative error code. 1933 */ 1934 static inline int nla_align_64bit(struct sk_buff *skb, int padattr) 1935 { 1936 if (nla_need_padding_for_64bit(skb) && 1937 !nla_reserve(skb, padattr, 0)) 1938 return -EMSGSIZE; 1939 1940 return 0; 1941 } 1942 1943 /** 1944 * nla_total_size_64bit - total length of attribute including padding 1945 * @payload: length of payload 1946 */ 1947 static inline int nla_total_size_64bit(int payload) 1948 { 1949 return NLA_ALIGN(nla_attr_size(payload)) 1950 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 1951 + NLA_ALIGN(nla_attr_size(0)) 1952 #endif 1953 ; 1954 } 1955 1956 /** 1957 * nla_for_each_attr - iterate over a stream of attributes 1958 * @pos: loop counter, set to current attribute 1959 * @head: head of attribute stream 1960 * @len: length of attribute stream 1961 * @rem: initialized to len, holds bytes currently remaining in stream 1962 */ 1963 #define nla_for_each_attr(pos, head, len, rem) \ 1964 for (pos = head, rem = len; \ 1965 nla_ok(pos, rem); \ 1966 pos = nla_next(pos, &(rem))) 1967 1968 /** 1969 * nla_for_each_nested - iterate over nested attributes 1970 * @pos: loop counter, set to current attribute 1971 * @nla: attribute containing the nested attributes 1972 * @rem: initialized to len, holds bytes currently remaining in stream 1973 */ 1974 #define nla_for_each_nested(pos, nla, rem) \ 1975 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 1976 1977 /** 1978 * nla_is_last - Test if attribute is last in stream 1979 * @nla: attribute to test 1980 * @rem: bytes remaining in stream 1981 */ 1982 static inline bool nla_is_last(const struct nlattr *nla, int rem) 1983 { 1984 return nla->nla_len == rem; 1985 } 1986 1987 void nla_get_range_unsigned(const struct nla_policy *pt, 1988 struct netlink_range_validation *range); 1989 void nla_get_range_signed(const struct nla_policy *pt, 1990 struct netlink_range_validation_signed *range); 1991 1992 struct netlink_policy_dump_state; 1993 1994 int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate, 1995 const struct nla_policy *policy, 1996 unsigned int maxtype); 1997 int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state, 1998 const struct nla_policy *policy, 1999 unsigned int maxtype); 2000 bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state); 2001 int netlink_policy_dump_write(struct sk_buff *skb, 2002 struct netlink_policy_dump_state *state); 2003 int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt); 2004 int netlink_policy_dump_write_attr(struct sk_buff *skb, 2005 const struct nla_policy *pt, 2006 int nestattr); 2007 void netlink_policy_dump_free(struct netlink_policy_dump_state *state); 2008 2009 #endif 2010