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 */ 165enum { 166 NLA_UNSPEC, 167 NLA_U8, 168 NLA_U16, 169 NLA_U32, 170 NLA_U64, 171 NLA_STRING, 172 NLA_FLAG, 173 NLA_MSECS, 174 NLA_NESTED, 175 NLA_NESTED_ARRAY, 176 NLA_NUL_STRING, 177 NLA_BINARY, 178 NLA_S8, 179 NLA_S16, 180 NLA_S32, 181 NLA_S64, 182 NLA_BITFIELD32, 183 NLA_REJECT, 184 NLA_EXACT_LEN, 185 NLA_EXACT_LEN_WARN, 186 NLA_MIN_LEN, 187 __NLA_TYPE_MAX, 188}; 189 190#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) 191 192struct netlink_range_validation { 193 u64 min, max; 194}; 195 196struct netlink_range_validation_signed { 197 s64 min, max; 198}; 199 200enum nla_policy_validation { 201 NLA_VALIDATE_NONE, 202 NLA_VALIDATE_RANGE, 203 NLA_VALIDATE_MIN, 204 NLA_VALIDATE_MAX, 205 NLA_VALIDATE_FUNCTION, 206 /* RHEL: any new enumerants need to be placed at the end to preserve 207 * KABI for older kernel modules. 208 */ 209 NLA_VALIDATE_RANGE_PTR, 210 NLA_VALIDATE_WARN_TOO_LONG, 211 NLA_VALIDATE_RANGE_WARN_TOO_LONG, 212 NLA_VALIDATE_MASK, 213}; 214 215/** 216 * struct nla_policy - attribute validation policy 217 * @type: Type of attribute or NLA_UNSPEC 218 * @validation_type: type of attribute validation done in addition to 219 * type-specific validation (e.g. range, function call), see 220 * &enum nla_policy_validation 221 * @len: Type specific length of payload 222 * 223 * Policies are defined as arrays of this struct, the array must be 224 * accessible by attribute type up to the highest identifier to be expected. 225 * 226 * Meaning of `len' field: 227 * NLA_STRING Maximum length of string 228 * NLA_NUL_STRING Maximum length of string (excluding NUL) 229 * NLA_FLAG Unused 230 * NLA_BINARY Maximum length of attribute payload 231 * (but see also below with the validation type) 232 * NLA_MIN_LEN Minimum length of attribute payload 233 * NLA_NESTED, 234 * NLA_NESTED_ARRAY Length verification is done by checking len of 235 * nested header (or empty); len field is used if 236 * nested_policy is also used, for the max attr 237 * number in the nested policy. 238 * NLA_U8, NLA_U16, 239 * NLA_U32, NLA_U64, 240 * NLA_S8, NLA_S16, 241 * NLA_S32, NLA_S64, 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 * NLA_EXACT_LEN Attribute should have exactly this length, otherwise 248 * it is rejected or warned about, the latter happening 249 * if and only if the `validation_type' is set to 250 * NLA_VALIDATE_WARN_TOO_LONG. 251 * NLA_EXACT_LEN_WARN Deprecated, to preserve the numerical values 252 * of the successors in kabi. 253 * NLA_MIN_LEN Minimum length of attribute payload 254 * All other Minimum length of attribute payload 255 * 256 * Meaning of validation union: 257 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and 258 * `bitfield32_valid_ptr' points to u32 value of valid 259 * flags. 260 * NLA_REJECT This attribute is always rejected and `reject_message' 261 * may point to a string to report as the error instead 262 * of the generic one in extended ACK. 263 * NLA_NESTED `nested_policy' to a nested policy to validate, must 264 * also set `len' to the max attribute number. Use the 265 * provided NLA_POLICY_NESTED() macro. 266 * Note that nla_parse() will validate, but of course not 267 * parse, the nested sub-policies. 268 * NLA_NESTED_ARRAY `nested_policy' points to a nested policy to validate, 269 * must also set `len' to the max attribute number. Use 270 * the provided NLA_POLICY_NESTED_ARRAY() macro. 271 * The difference to NLA_NESTED is the structure: 272 * NLA_NESTED has the nested attributes directly inside 273 * while an array has the nested attributes at another 274 * level down and the attribute types directly in the 275 * nesting don't matter. 276 * NLA_U8, 277 * NLA_U16, 278 * NLA_U32, 279 * NLA_U64, 280 * NLA_S8, 281 * NLA_S16, 282 * NLA_S32, 283 * NLA_S64 The `min' and `max' fields are used depending on the 284 * validation_type field, if that is min/max/range then 285 * the min, max or both are used (respectively) to check 286 * the value of the integer attribute. 287 * Note that in the interest of code simplicity and 288 * struct size both limits are s16, so you cannot 289 * enforce a range that doesn't fall within the range 290 * of s16 - do that as usual in the code instead. 291 * Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and 292 * NLA_POLICY_RANGE() macros. 293 * NLA_U8, 294 * NLA_U16, 295 * NLA_U32, 296 * NLA_U64 If the validation_type field instead is set to 297 * NLA_VALIDATE_RANGE_PTR, `range' must be a pointer 298 * to a struct netlink_range_validation that indicates 299 * the min/max values. 300 * Use NLA_POLICY_FULL_RANGE(). 301 * NLA_S8, 302 * NLA_S16, 303 * NLA_S32, 304 * NLA_S64 If the validation_type field instead is set to 305 * NLA_VALIDATE_RANGE_PTR, `range_signed' must be a 306 * pointer to a struct netlink_range_validation_signed 307 * that indicates the min/max values. 308 * Use NLA_POLICY_FULL_RANGE_SIGNED(). 309 * 310 * NLA_BINARY If the validation type is like the ones for integers 311 * above, then the min/max length (not value like for 312 * integers) of the attribute is enforced. 313 * 314 * All other Unused - but note that it's a union 315 * 316 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN: 317 * NLA_BINARY Validation function called for the attribute. 318 * All other Unused - but note that it's a union 319 * 320 * Example: 321 * 322 * static const u32 myvalidflags = 0xff231023; 323 * 324 * static const struct nla_policy my_policy[ATTR_MAX+1] = { 325 * [ATTR_FOO] = { .type = NLA_U16 }, 326 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, 327 * [ATTR_BAZ] = { .type = NLA_EXACT_LEN, .len = sizeof(struct mystruct) }, 328 * [ATTR_GOO] = NLA_POLICY_BITFIELD32_PTR(&myvalidflags), 329 * }; 330 */ 331struct nla_policy { 332#ifdef __BIG_ENDIAN__ 333 RH_KABI_REPLACE_SPLIT(u16 type, 334 u8 validation_type, 335 u8 type) 336#else 337 RH_KABI_REPLACE_SPLIT(u16 type, 338 u8 type, 339 u8 validation_type) 340#endif 341 u16 len; 342#ifdef __GENKSYMS__ 343 void *validation_data; 344#else 345 union { 346 /* RHEL: Older binary modules expected validation_data pointer. 347 * To preserve backward compatibility we use u32* 348 * bitfield32_valid_ptr instead of upstream u32 349 * bitfield32_valid. Old modules can safe dereference it. 350 */ 351 const u32 *bitfield32_valid_ptr; 352 const u32 mask; 353 const char *reject_message; 354 const struct nla_policy *nested_policy; 355 struct netlink_range_validation *range; 356 struct netlink_range_validation_signed *range_signed; 357 struct { 358 s16 min, max; 359 }; 360 int (*validate)(const struct nlattr *attr, 361 struct netlink_ext_ack *extack); 362 /* This entry is special, and used for the attribute at index 0 363 * only, and specifies special data about the policy, namely it 364 * specifies the "boundary type" where strict length validation 365 * starts for any attribute types >= this value, also, strict 366 * nesting validation starts here. 367 * 368 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT 369 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to 370 * get the previous pure { .len = xyz } behaviour. The advantage 371 * of this is that types not specified in the policy will be 372 * rejected. 373 * 374 * For completely new families it should be set to 1 so that the 375 * validation is enforced for all attributes. For existing ones 376 * it should be set at least when new attributes are added to 377 * the enum used by the policy, and be set to the new value that 378 * was added to enforce strict validation from thereon. 379 */ 380 u16 strict_start_type; 381 }; 382#endif 383}; 384 385/* RHEL only: make sure the union doesn't grow and is aligned 386 * to the end of the struct, like the original field. 387 */ 388static_assert(offsetofend(struct nla_policy, 389 bitfield32_valid_ptr) == sizeof(struct nla_policy), 390 "The size of struct nla_policy is fixed and cannot be changed"); 391 392#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) 393#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) 394 395#define _NLA_POLICY_NESTED(maxattr, policy) \ 396 { .type = NLA_NESTED, .nested_policy = policy, .len = maxattr } 397#define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ 398 { .type = NLA_NESTED_ARRAY, .nested_policy = policy, .len = maxattr } 399#define NLA_POLICY_NESTED(policy) \ 400 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy) 401#define NLA_POLICY_NESTED_ARRAY(policy) \ 402 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy) 403#define NLA_POLICY_BITFIELD32_PTR(valid) \ 404 { .type = NLA_BITFIELD32, .bitfield32_valid_ptr = valid } 405 406#define __NLA_IS_UINT_TYPE(tp) \ 407 (tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || tp == NLA_U64) 408#define __NLA_IS_SINT_TYPE(tp) \ 409 (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64) 410 411#define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition)) 412#define NLA_ENSURE_UINT_TYPE(tp) \ 413 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \ 414 tp == NLA_MSECS) + tp) 415#define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp) \ 416 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \ 417 tp == NLA_MSECS || \ 418 tp == NLA_BINARY) + tp) 419#define NLA_ENSURE_SINT_TYPE(tp) \ 420 (__NLA_ENSURE(__NLA_IS_SINT_TYPE(tp)) + tp) 421#define NLA_ENSURE_INT_TYPE(tp) \ 422 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \ 423 __NLA_IS_SINT_TYPE(tp) || \ 424 tp == NLA_MSECS) + tp) 425#define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \ 426 (__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \ 427 __NLA_IS_SINT_TYPE(tp) || \ 428 tp == NLA_MSECS || \ 429 tp == NLA_BINARY) + tp) 430#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \ 431 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \ 432 tp != NLA_REJECT && \ 433 tp != NLA_NESTED && \ 434 tp != NLA_NESTED_ARRAY) + tp) 435 436#define NLA_POLICY_RANGE(tp, _min, _max) { \ 437 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 438 .validation_type = NLA_VALIDATE_RANGE, \ 439 .min = _min, \ 440 .max = _max \ 441} 442 443#define NLA_POLICY_FULL_RANGE(tp, _range) { \ 444 .type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp), \ 445 .validation_type = NLA_VALIDATE_RANGE_PTR, \ 446 .range = _range, \ 447} 448 449#define NLA_POLICY_FULL_RANGE_SIGNED(tp, _range) { \ 450 .type = NLA_ENSURE_SINT_TYPE(tp), \ 451 .validation_type = NLA_VALIDATE_RANGE_PTR, \ 452 .range_signed = _range, \ 453} 454 455#define NLA_POLICY_MIN(tp, _min) { \ 456 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 457 .validation_type = NLA_VALIDATE_MIN, \ 458 .min = _min, \ 459} 460 461#define NLA_POLICY_MAX(tp, _max) { \ 462 .type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \ 463 .validation_type = NLA_VALIDATE_MAX, \ 464 .max = _max, \ 465} 466 467#define NLA_POLICY_MASK(tp, _mask) { \ 468 .type = NLA_ENSURE_UINT_TYPE(tp), \ 469 .validation_type = NLA_VALIDATE_MASK, \ 470 .mask = _mask, \ 471} 472 473#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \ 474 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \ 475 .validation_type = NLA_VALIDATE_FUNCTION, \ 476 .validate = fn, \ 477 .len = __VA_ARGS__ + 0, \ 478} 479 480#define NLA_POLICY_EXACT_LEN(_len) NLA_POLICY_RANGE(NLA_BINARY, _len, _len) 481#define NLA_POLICY_EXACT_LEN_WARN(_len) { \ 482 .type = NLA_BINARY, \ 483 .validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG, \ 484 .min = _len, \ 485 .max = _len \ 486} 487#define NLA_POLICY_MIN_LEN(_len) NLA_POLICY_MIN(NLA_BINARY, _len) 488 489/** 490 * struct nl_info - netlink source information 491 * @nlh: Netlink message header of original request 492 * @nl_net: Network namespace 493 * @portid: Netlink PORTID of requesting application 494 * @skip_notify: Skip netlink notifications to user space 495 * @skip_notify_kernel: Skip selected in-kernel notifications 496 */ 497struct nl_info { 498 struct nlmsghdr *nlh; 499 struct net *nl_net; 500 u32 portid; 501 u8 skip_notify:1, 502 skip_notify_kernel:1; 503}; 504 505/** 506 * enum netlink_validation - netlink message/attribute validation levels 507 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about 508 * extra data at the end of the message, attributes being longer than 509 * they should be, or unknown attributes being present. 510 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing. 511 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING 512 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict(). 513 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy. 514 * This can safely be set by the kernel when the given policy has no 515 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries 516 * are enforced going forward. 517 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g. 518 * U8, U16, U32 must have exact size, etc.) 519 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY) 520 * and unset for other policies. 521 */ 522enum netlink_validation { 523 NL_VALIDATE_LIBERAL = 0, 524 NL_VALIDATE_TRAILING = BIT(0), 525 NL_VALIDATE_MAXTYPE = BIT(1), 526 NL_VALIDATE_UNSPEC = BIT(2), 527 NL_VALIDATE_STRICT_ATTRS = BIT(3), 528 NL_VALIDATE_NESTED = BIT(4), 529}; 530 531#define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\ 532 NL_VALIDATE_MAXTYPE) 533#define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\ 534 NL_VALIDATE_MAXTYPE |\ 535 NL_VALIDATE_UNSPEC |\ 536 NL_VALIDATE_STRICT_ATTRS |\ 537 NL_VALIDATE_NESTED) 538 539int netlink_rcv_skb(struct sk_buff *skb, 540 int (*cb)(struct sk_buff *, struct nlmsghdr *, 541 struct netlink_ext_ack *)); 542int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, 543 unsigned int group, int report, gfp_t flags); 544 545int __nla_validate(const struct nlattr *head, int len, int maxtype, 546 const struct nla_policy *policy, unsigned int validate, 547 struct netlink_ext_ack *extack); 548int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, 549 int len, const struct nla_policy *policy, unsigned int validate, 550 struct netlink_ext_ack *extack); 551int nla_policy_len(const struct nla_policy *, int); 552struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype); 553ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize); 554char *nla_strdup(const struct nlattr *nla, gfp_t flags); 555int nla_memcpy(void *dest, const struct nlattr *src, int count); 556int nla_memcmp(const struct nlattr *nla, const void *data, size_t size); 557int nla_strcmp(const struct nlattr *nla, const char *str); 558struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 559struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, 560 int attrlen, int padattr); 561void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 562struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 563struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, 564 int attrlen, int padattr); 565void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 566void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, 567 const void *data); 568void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 569 const void *data, int padattr); 570void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 571int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); 572int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 573 const void *data, int padattr); 574int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 575int nla_append(struct sk_buff *skb, int attrlen, const void *data); 576 577/************************************************************************** 578 * Netlink Messages 579 **************************************************************************/ 580 581/** 582 * nlmsg_msg_size - length of netlink message not including padding 583 * @payload: length of message payload 584 */ 585static inline int nlmsg_msg_size(int payload) 586{ 587 return NLMSG_HDRLEN + payload; 588} 589 590/** 591 * nlmsg_total_size - length of netlink message including padding 592 * @payload: length of message payload 593 */ 594static inline int nlmsg_total_size(int payload) 595{ 596 return NLMSG_ALIGN(nlmsg_msg_size(payload)); 597} 598 599/** 600 * nlmsg_padlen - length of padding at the message's tail 601 * @payload: length of message payload 602 */ 603static inline int nlmsg_padlen(int payload) 604{ 605 return nlmsg_total_size(payload) - nlmsg_msg_size(payload); 606} 607 608/** 609 * nlmsg_data - head of message payload 610 * @nlh: netlink message header 611 */ 612static inline void *nlmsg_data(const struct nlmsghdr *nlh) 613{ 614 return (unsigned char *) nlh + NLMSG_HDRLEN; 615} 616 617/** 618 * nlmsg_len - length of message payload 619 * @nlh: netlink message header 620 */ 621static inline int nlmsg_len(const struct nlmsghdr *nlh) 622{ 623 return nlh->nlmsg_len - NLMSG_HDRLEN; 624} 625 626/** 627 * nlmsg_attrdata - head of attributes data 628 * @nlh: netlink message header 629 * @hdrlen: length of family specific header 630 */ 631static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 632 int hdrlen) 633{ 634 unsigned char *data = nlmsg_data(nlh); 635 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); 636} 637 638/** 639 * nlmsg_attrlen - length of attributes data 640 * @nlh: netlink message header 641 * @hdrlen: length of family specific header 642 */ 643static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) 644{ 645 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); 646} 647 648/** 649 * nlmsg_ok - check if the netlink message fits into the remaining bytes 650 * @nlh: netlink message header 651 * @remaining: number of bytes remaining in message stream 652 */ 653static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) 654{ 655 return (remaining >= (int) sizeof(struct nlmsghdr) && 656 nlh->nlmsg_len >= sizeof(struct nlmsghdr) && 657 nlh->nlmsg_len <= remaining); 658} 659 660/** 661 * nlmsg_next - next netlink message in message stream 662 * @nlh: netlink message header 663 * @remaining: number of bytes remaining in message stream 664 * 665 * Returns the next netlink message in the message stream and 666 * decrements remaining by the size of the current message. 667 */ 668static inline struct nlmsghdr * 669nlmsg_next(const struct nlmsghdr *nlh, int *remaining) 670{ 671 int totlen = NLMSG_ALIGN(nlh->nlmsg_len); 672 673 *remaining -= totlen; 674 675 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); 676} 677 678/** 679 * nla_parse - Parse a stream of attributes into a tb buffer 680 * @tb: destination array with maxtype+1 elements 681 * @maxtype: maximum attribute type to be expected 682 * @head: head of attribute stream 683 * @len: length of attribute stream 684 * @policy: validation policy 685 * @extack: extended ACK pointer 686 * 687 * Parses a stream of attributes and stores a pointer to each attribute in 688 * the tb array accessible via the attribute type. Attributes with a type 689 * exceeding maxtype will be rejected, policy must be specified, attributes 690 * will be validated in the strictest way possible. 691 * 692 * Returns 0 on success or a negative error code. 693 */ 694static inline int nla_parse(struct nlattr **tb, int maxtype, 695 const struct nlattr *head, int len, 696 const struct nla_policy *policy, 697 struct netlink_ext_ack *extack) 698{ 699 return __nla_parse(tb, maxtype, head, len, policy, 700 NL_VALIDATE_STRICT, extack); 701} 702 703/** 704 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer 705 * @tb: destination array with maxtype+1 elements 706 * @maxtype: maximum attribute type to be expected 707 * @head: head of attribute stream 708 * @len: length of attribute stream 709 * @policy: validation policy 710 * @extack: extended ACK pointer 711 * 712 * Parses a stream of attributes and stores a pointer to each attribute in 713 * the tb array accessible via the attribute type. Attributes with a type 714 * exceeding maxtype will be ignored and attributes from the policy are not 715 * always strictly validated (only for new attributes). 716 * 717 * Returns 0 on success or a negative error code. 718 */ 719static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype, 720 const struct nlattr *head, int len, 721 const struct nla_policy *policy, 722 struct netlink_ext_ack *extack) 723{ 724 return __nla_parse(tb, maxtype, head, len, policy, 725 NL_VALIDATE_LIBERAL, extack); 726} 727 728/** 729 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer 730 * @tb: destination array with maxtype+1 elements 731 * @maxtype: maximum attribute type to be expected 732 * @head: head of attribute stream 733 * @len: length of attribute stream 734 * @policy: validation policy 735 * @extack: extended ACK pointer 736 * 737 * Parses a stream of attributes and stores a pointer to each attribute in 738 * the tb array accessible via the attribute type. Attributes with a type 739 * exceeding maxtype will be rejected as well as trailing data, but the 740 * policy is not completely strictly validated (only for new attributes). 741 * 742 * Returns 0 on success or a negative error code. 743 */ 744static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype, 745 const struct nlattr *head, 746 int len, 747 const struct nla_policy *policy, 748 struct netlink_ext_ack *extack) 749{ 750 return __nla_parse(tb, maxtype, head, len, policy, 751 NL_VALIDATE_DEPRECATED_STRICT, extack); 752} 753 754/** 755 * __nlmsg_parse - parse attributes of a netlink message 756 * @nlh: netlink message header 757 * @hdrlen: length of family specific header 758 * @tb: destination array with maxtype+1 elements 759 * @maxtype: maximum attribute type to be expected 760 * @policy: validation policy 761 * @validate: validation strictness 762 * @extack: extended ACK report struct 763 * 764 * See nla_parse() 765 */ 766static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 767 struct nlattr *tb[], int maxtype, 768 const struct nla_policy *policy, 769 unsigned int validate, 770 struct netlink_ext_ack *extack) 771{ 772 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) { 773 NL_SET_ERR_MSG(extack, "Invalid header length"); 774 return -EINVAL; 775 } 776 777 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 778 nlmsg_attrlen(nlh, hdrlen), policy, validate, 779 extack); 780} 781 782/** 783 * nlmsg_parse - parse attributes of a netlink message 784 * @nlh: netlink message header 785 * @hdrlen: length of family specific header 786 * @tb: destination array with maxtype+1 elements 787 * @maxtype: maximum attribute type to be expected 788 * @validate: validation strictness 789 * @extack: extended ACK report struct 790 * 791 * See nla_parse() 792 */ 793static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 794 struct nlattr *tb[], int maxtype, 795 const struct nla_policy *policy, 796 struct netlink_ext_ack *extack) 797{ 798 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 799 NL_VALIDATE_STRICT, extack); 800} 801 802/** 803 * nlmsg_parse_deprecated - parse attributes of a netlink message 804 * @nlh: netlink message header 805 * @hdrlen: length of family specific header 806 * @tb: destination array with maxtype+1 elements 807 * @maxtype: maximum attribute type to be expected 808 * @extack: extended ACK report struct 809 * 810 * See nla_parse_deprecated() 811 */ 812static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen, 813 struct nlattr *tb[], int maxtype, 814 const struct nla_policy *policy, 815 struct netlink_ext_ack *extack) 816{ 817 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 818 NL_VALIDATE_LIBERAL, extack); 819} 820 821/** 822 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message 823 * @nlh: netlink message header 824 * @hdrlen: length of family specific header 825 * @tb: destination array with maxtype+1 elements 826 * @maxtype: maximum attribute type to be expected 827 * @extack: extended ACK report struct 828 * 829 * See nla_parse_deprecated_strict() 830 */ 831static inline int 832nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen, 833 struct nlattr *tb[], int maxtype, 834 const struct nla_policy *policy, 835 struct netlink_ext_ack *extack) 836{ 837 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 838 NL_VALIDATE_DEPRECATED_STRICT, extack); 839} 840 841/** 842 * nlmsg_find_attr - find a specific attribute in a netlink message 843 * @nlh: netlink message header 844 * @hdrlen: length of familiy specific header 845 * @attrtype: type of attribute to look for 846 * 847 * Returns the first attribute which matches the specified type. 848 */ 849static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh, 850 int hdrlen, int attrtype) 851{ 852 return nla_find(nlmsg_attrdata(nlh, hdrlen), 853 nlmsg_attrlen(nlh, hdrlen), attrtype); 854} 855 856/** 857 * nla_validate_deprecated - Validate a stream of attributes 858 * @head: head of attribute stream 859 * @len: length of attribute stream 860 * @maxtype: maximum attribute type to be expected 861 * @policy: validation policy 862 * @validate: validation strictness 863 * @extack: extended ACK report struct 864 * 865 * Validates all attributes in the specified attribute stream against the 866 * specified policy. Validation is done in liberal mode. 867 * See documenation of struct nla_policy for more details. 868 * 869 * Returns 0 on success or a negative error code. 870 */ 871static inline int nla_validate_deprecated(const struct nlattr *head, int len, 872 int maxtype, 873 const struct nla_policy *policy, 874 struct netlink_ext_ack *extack) 875{ 876 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL, 877 extack); 878} 879 880/** 881 * nla_validate - Validate a stream of attributes 882 * @head: head of attribute stream 883 * @len: length of attribute stream 884 * @maxtype: maximum attribute type to be expected 885 * @policy: validation policy 886 * @validate: validation strictness 887 * @extack: extended ACK report struct 888 * 889 * Validates all attributes in the specified attribute stream against the 890 * specified policy. Validation is done in strict mode. 891 * See documenation of struct nla_policy for more details. 892 * 893 * Returns 0 on success or a negative error code. 894 */ 895static inline int nla_validate(const struct nlattr *head, int len, int maxtype, 896 const struct nla_policy *policy, 897 struct netlink_ext_ack *extack) 898{ 899 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT, 900 extack); 901} 902 903/** 904 * nlmsg_validate_deprecated - validate a netlink message including attributes 905 * @nlh: netlinket message header 906 * @hdrlen: length of familiy specific header 907 * @maxtype: maximum attribute type to be expected 908 * @policy: validation policy 909 * @extack: extended ACK report struct 910 */ 911static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh, 912 int hdrlen, int maxtype, 913 const struct nla_policy *policy, 914 struct netlink_ext_ack *extack) 915{ 916 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 917 return -EINVAL; 918 919 return __nla_validate(nlmsg_attrdata(nlh, hdrlen), 920 nlmsg_attrlen(nlh, hdrlen), maxtype, 921 policy, NL_VALIDATE_LIBERAL, extack); 922} 923 924 925 926/** 927 * nlmsg_report - need to report back to application? 928 * @nlh: netlink message header 929 * 930 * Returns 1 if a report back to the application is requested. 931 */ 932static inline int nlmsg_report(const struct nlmsghdr *nlh) 933{ 934 return !!(nlh->nlmsg_flags & NLM_F_ECHO); 935} 936 937/** 938 * nlmsg_for_each_attr - iterate over a stream of attributes 939 * @pos: loop counter, set to current attribute 940 * @nlh: netlink message header 941 * @hdrlen: length of familiy specific header 942 * @rem: initialized to len, holds bytes currently remaining in stream 943 */ 944#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ 945 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ 946 nlmsg_attrlen(nlh, hdrlen), rem) 947 948/** 949 * nlmsg_put - Add a new netlink message to an skb 950 * @skb: socket buffer to store message in 951 * @portid: netlink PORTID of requesting application 952 * @seq: sequence number of message 953 * @type: message type 954 * @payload: length of message payload 955 * @flags: message flags 956 * 957 * Returns NULL if the tailroom of the skb is insufficient to store 958 * the message header and payload. 959 */ 960static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, 961 int type, int payload, int flags) 962{ 963 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) 964 return NULL; 965 966 return __nlmsg_put(skb, portid, seq, type, payload, flags); 967} 968 969/** 970 * nlmsg_put_answer - Add a new callback based netlink message to an skb 971 * @skb: socket buffer to store message in 972 * @cb: netlink callback 973 * @type: message type 974 * @payload: length of message payload 975 * @flags: message flags 976 * 977 * Returns NULL if the tailroom of the skb is insufficient to store 978 * the message header and payload. 979 */ 980static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, 981 struct netlink_callback *cb, 982 int type, int payload, 983 int flags) 984{ 985 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 986 type, payload, flags); 987} 988 989/** 990 * nlmsg_new - Allocate a new netlink message 991 * @payload: size of the message payload 992 * @flags: the type of memory to allocate. 993 * 994 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known 995 * and a good default is needed. 996 */ 997static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) 998{ 999 return alloc_skb(nlmsg_total_size(payload), flags); 1000}
1001 1002/** 1003 * nlmsg_end - Finalize a netlink message 1004 * @skb: socket buffer the message is stored in 1005 * @nlh: netlink message header 1006 * 1007 * Corrects the netlink message header to include the appeneded 1008 * attributes. Only necessary if attributes have been added to 1009 * the message. 1010 */ 1011static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 1012{ 1013 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 1014} 1015 1016/** 1017 * nlmsg_get_pos - return current position in netlink message 1018 * @skb: socket buffer the message is stored in 1019 * 1020 * Returns a pointer to the current tail of the message. 1021 */ 1022static inline void *nlmsg_get_pos(struct sk_buff *skb) 1023{ 1024 return skb_tail_pointer(skb); 1025} 1026 1027/** 1028 * nlmsg_trim - Trim message to a mark 1029 * @skb: socket buffer the message is stored in 1030 * @mark: mark to trim to 1031 * 1032 * Trims the message to the provided mark. 1033 */ 1034static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 1035{ 1036 if (mark) { 1037 WARN_ON((unsigned char *) mark < skb->data); 1038 skb_trim(skb, (unsigned char *) mark - skb->data); 1039 } 1040} 1041 1042/** 1043 * nlmsg_cancel - Cancel construction of a netlink message 1044 * @skb: socket buffer the message is stored in 1045 * @nlh: netlink message header 1046 * 1047 * Removes the complete netlink message including all 1048 * attributes from the socket buffer again. 1049 */ 1050static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 1051{ 1052 nlmsg_trim(skb, nlh); 1053} 1054 1055/** 1056 * nlmsg_free - free a netlink message 1057 * @skb: socket buffer of netlink message 1058 */ 1059static inline void nlmsg_free(struct sk_buff *skb) 1060{ 1061 kfree_skb(skb); 1062} 1063 1064/** 1065 * nlmsg_multicast - multicast a netlink message 1066 * @sk: netlink socket to spread messages to 1067 * @skb: netlink message as socket buffer 1068 * @portid: own netlink portid to avoid sending to yourself 1069 * @group: multicast group id 1070 * @flags: allocation flags 1071 */ 1072static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 1073 u32 portid, unsigned int group, gfp_t flags) 1074{ 1075 int err; 1076 1077 NETLINK_CB(skb).dst_group = group; 1078 1079 err = netlink_broadcast(sk, skb, portid, group, flags); 1080 if (err > 0) 1081 err = 0; 1082 1083 return err; 1084} 1085 1086/** 1087 * nlmsg_unicast - unicast a netlink message 1088 * @sk: netlink socket to spread message to 1089 * @skb: netlink message as socket buffer 1090 * @portid: netlink portid of the destination socket 1091 */ 1092static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid) 1093{ 1094 int err; 1095 1096 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT); 1097 if (err > 0) 1098 err = 0; 1099 1100 return err; 1101} 1102 1103/** 1104 * nlmsg_for_each_msg - iterate over a stream of messages 1105 * @pos: loop counter, set to current message 1106 * @head: head of message stream 1107 * @len: length of message stream 1108 * @rem: initialized to len, holds bytes currently remaining in stream 1109 */ 1110#define nlmsg_for_each_msg(pos, head, len, rem) \ 1111 for (pos = head, rem = len; \ 1112 nlmsg_ok(pos, rem); \ 1113 pos = nlmsg_next(pos, &(rem))) 1114 1115/** 1116 * nl_dump_check_consistent - check if sequence is consistent and advertise if not 1117 * @cb: netlink callback structure that stores the sequence number 1118 * @nlh: netlink message header to write the flag to 1119 * 1120 * This function checks if the sequence (generation) number changed during dump 1121 * and if it did, advertises it in the netlink message header. 1122 * 1123 * The correct way to use it is to set cb->seq to the generation counter when 1124 * all locks for dumping have been acquired, and then call this function for 1125 * each message that is generated. 1126 * 1127 * Note that due to initialisation concerns, 0 is an invalid sequence number 1128 * and must not be used by code that uses this functionality. 1129 */ 1130static inline void 1131nl_dump_check_consistent(struct netlink_callback *cb, 1132 struct nlmsghdr *nlh) 1133{ 1134 if (cb->prev_seq && cb->seq != cb->prev_seq) 1135 nlh->nlmsg_flags |= NLM_F_DUMP_INTR; 1136 cb->prev_seq = cb->seq; 1137} 1138 1139/************************************************************************** 1140 * Netlink Attributes 1141 **************************************************************************/ 1142 1143/** 1144 * nla_attr_size - length of attribute not including padding 1145 * @payload: length of payload 1146 */ 1147static inline int nla_attr_size(int payload) 1148{ 1149 return NLA_HDRLEN + payload; 1150} 1151 1152/** 1153 * nla_total_size - total length of attribute including padding 1154 * @payload: length of payload 1155 */ 1156static inline int nla_total_size(int payload) 1157{ 1158 return NLA_ALIGN(nla_attr_size(payload)); 1159} 1160 1161/** 1162 * nla_padlen - length of padding at the tail of attribute 1163 * @payload: length of payload 1164 */ 1165static inline int nla_padlen(int payload) 1166{ 1167 return nla_total_size(payload) - nla_attr_size(payload); 1168} 1169 1170/** 1171 * nla_type - attribute type 1172 * @nla: netlink attribute 1173 */ 1174static inline int nla_type(const struct nlattr *nla) 1175{ 1176 return nla->nla_type & NLA_TYPE_MASK; 1177} 1178 1179/** 1180 * nla_data - head of payload 1181 * @nla: netlink attribute 1182 */ 1183static inline void *nla_data(const struct nlattr *nla) 1184{ 1185 return (char *) nla + NLA_HDRLEN; 1186} 1187 1188/** 1189 * nla_len - length of payload 1190 * @nla: netlink attribute 1191 */ 1192static inline int nla_len(const struct nlattr *nla) 1193{ 1194 return nla->nla_len - NLA_HDRLEN; 1195} 1196 1197/** 1198 * nla_ok - check if the netlink attribute fits into the remaining bytes 1199 * @nla: netlink attribute 1200 * @remaining: number of bytes remaining in attribute stream 1201 */ 1202static inline int nla_ok(const struct nlattr *nla, int remaining) 1203{ 1204 return remaining >= (int) sizeof(*nla) && 1205 nla->nla_len >= sizeof(*nla) && 1206 nla->nla_len <= remaining; 1207} 1208 1209/** 1210 * nla_next - next netlink attribute in attribute stream 1211 * @nla: netlink attribute 1212 * @remaining: number of bytes remaining in attribute stream 1213 * 1214 * Returns the next netlink attribute in the attribute stream and 1215 * decrements remaining by the size of the current attribute. 1216 */ 1217static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 1218{ 1219 unsigned int totlen = NLA_ALIGN(nla->nla_len); 1220 1221 *remaining -= totlen; 1222 return (struct nlattr *) ((char *) nla + totlen); 1223} 1224 1225/** 1226 * nla_find_nested - find attribute in a set of nested attributes 1227 * @nla: attribute containing the nested attributes 1228 * @attrtype: type of attribute to look for 1229 * 1230 * Returns the first attribute which matches the specified type. 1231 */ 1232static inline struct nlattr * 1233nla_find_nested(const struct nlattr *nla, int attrtype) 1234{ 1235 return nla_find(nla_data(nla), nla_len(nla), attrtype); 1236} 1237 1238/** 1239 * nla_parse_nested - parse nested attributes 1240 * @tb: destination array with maxtype+1 elements 1241 * @maxtype: maximum attribute type to be expected 1242 * @nla: attribute containing the nested attributes 1243 * @policy: validation policy 1244 * @extack: extended ACK report struct 1245 * 1246 * See nla_parse() 1247 */ 1248static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 1249 const struct nlattr *nla, 1250 const struct nla_policy *policy, 1251 struct netlink_ext_ack *extack) 1252{ 1253 if (!(nla->nla_type & NLA_F_NESTED)) { 1254 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing"); 1255 return -EINVAL; 1256 } 1257 1258 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, 1259 NL_VALIDATE_STRICT, extack); 1260} 1261 1262/** 1263 * nla_parse_nested_deprecated - parse nested attributes 1264 * @tb: destination array with maxtype+1 elements 1265 * @maxtype: maximum attribute type to be expected 1266 * @nla: attribute containing the nested attributes 1267 * @policy: validation policy 1268 * @extack: extended ACK report struct 1269 * 1270 * See nla_parse_deprecated() 1271 */ 1272static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype, 1273 const struct nlattr *nla, 1274 const struct nla_policy *policy, 1275 struct netlink_ext_ack *extack) 1276{ 1277 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, 1278 NL_VALIDATE_LIBERAL, extack); 1279} 1280 1281/** 1282 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 1283 * @skb: socket buffer to add attribute to 1284 * @attrtype: attribute type 1285 * @value: numeric value 1286 */ 1287static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 1288{ 1289 /* temporary variables to work around GCC PR81715 with asan-stack=1 */ 1290 u8 tmp = value; 1291 1292 return nla_put(skb, attrtype, sizeof(u8), &tmp); 1293} 1294 1295/** 1296 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer 1297 * @skb: socket buffer to add attribute to 1298 * @attrtype: attribute type 1299 * @value: numeric value 1300 */ 1301static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) 1302{ 1303 u16 tmp = value; 1304 1305 return nla_put(skb, attrtype, sizeof(u16), &tmp); 1306} 1307 1308/** 1309 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer 1310 * @skb: socket buffer to add attribute to 1311 * @attrtype: attribute type 1312 * @value: numeric value 1313 */ 1314static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value) 1315{ 1316 __be16 tmp = value; 1317 1318 return nla_put(skb, attrtype, sizeof(__be16), &tmp); 1319} 1320 1321/** 1322 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer 1323 * @skb: socket buffer to add attribute to 1324 * @attrtype: attribute type 1325 * @value: numeric value 1326 */ 1327static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value) 1328{ 1329 __be16 tmp = value; 1330 1331 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 1332} 1333 1334/** 1335 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer 1336 * @skb: socket buffer to add attribute to 1337 * @attrtype: attribute type 1338 * @value: numeric value 1339 */ 1340static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value) 1341{ 1342 __le16 tmp = value; 1343 1344 return nla_put(skb, attrtype, sizeof(__le16), &tmp); 1345} 1346 1347/** 1348 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 1349 * @skb: socket buffer to add attribute to 1350 * @attrtype: attribute type 1351 * @value: numeric value 1352 */ 1353static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 1354{ 1355 u32 tmp = value; 1356 1357 return nla_put(skb, attrtype, sizeof(u32), &tmp); 1358} 1359 1360/** 1361 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer 1362 * @skb: socket buffer to add attribute to 1363 * @attrtype: attribute type 1364 * @value: numeric value 1365 */ 1366static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value) 1367{ 1368 __be32 tmp = value; 1369 1370 return nla_put(skb, attrtype, sizeof(__be32), &tmp); 1371} 1372 1373/** 1374 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer 1375 * @skb: socket buffer to add attribute to 1376 * @attrtype: attribute type 1377 * @value: numeric value 1378 */ 1379static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value) 1380{ 1381 __be32 tmp = value; 1382 1383 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 1384} 1385 1386/** 1387 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer 1388 * @skb: socket buffer to add attribute to 1389 * @attrtype: attribute type 1390 * @value: numeric value 1391 */ 1392static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value) 1393{ 1394 __le32 tmp = value; 1395 1396 return nla_put(skb, attrtype, sizeof(__le32), &tmp); 1397} 1398 1399/** 1400 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it 1401 * @skb: socket buffer to add attribute to 1402 * @attrtype: attribute type 1403 * @value: numeric value 1404 * @padattr: attribute type for the padding 1405 */ 1406static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype, 1407 u64 value, int padattr) 1408{ 1409 u64 tmp = value; 1410 1411 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1412} 1413 1414/** 1415 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it 1416 * @skb: socket buffer to add attribute to 1417 * @attrtype: attribute type 1418 * @value: numeric value 1419 * @padattr: attribute type for the padding 1420 */ 1421static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value, 1422 int padattr) 1423{ 1424 __be64 tmp = value; 1425 1426 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr); 1427} 1428 1429/** 1430 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it 1431 * @skb: socket buffer to add attribute to 1432 * @attrtype: attribute type 1433 * @value: numeric value 1434 * @padattr: attribute type for the padding 1435 */ 1436static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value, 1437 int padattr) 1438{ 1439 __be64 tmp = value; 1440 1441 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp, 1442 padattr); 1443} 1444 1445/** 1446 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it 1447 * @skb: socket buffer to add attribute to 1448 * @attrtype: attribute type 1449 * @value: numeric value 1450 * @padattr: attribute type for the padding 1451 */ 1452static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value, 1453 int padattr) 1454{ 1455 __le64 tmp = value; 1456 1457 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr); 1458} 1459 1460/** 1461 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer 1462 * @skb: socket buffer to add attribute to 1463 * @attrtype: attribute type 1464 * @value: numeric value 1465 */ 1466static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value) 1467{ 1468 s8 tmp = value; 1469 1470 return nla_put(skb, attrtype, sizeof(s8), &tmp); 1471} 1472 1473/** 1474 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer 1475 * @skb: socket buffer to add attribute to 1476 * @attrtype: attribute type 1477 * @value: numeric value 1478 */ 1479static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value) 1480{ 1481 s16 tmp = value; 1482 1483 return nla_put(skb, attrtype, sizeof(s16), &tmp); 1484} 1485 1486/** 1487 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer 1488 * @skb: socket buffer to add attribute to 1489 * @attrtype: attribute type 1490 * @value: numeric value 1491 */ 1492static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value) 1493{ 1494 s32 tmp = value; 1495 1496 return nla_put(skb, attrtype, sizeof(s32), &tmp); 1497} 1498 1499/** 1500 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it 1501 * @skb: socket buffer to add attribute to 1502 * @attrtype: attribute type 1503 * @value: numeric value 1504 * @padattr: attribute type for the padding 1505 */ 1506static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value, 1507 int padattr) 1508{ 1509 s64 tmp = value; 1510 1511 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr); 1512} 1513 1514/** 1515 * nla_put_string - Add a string netlink attribute to a socket buffer 1516 * @skb: socket buffer to add attribute to 1517 * @attrtype: attribute type 1518 * @str: NUL terminated string 1519 */ 1520static inline int nla_put_string(struct sk_buff *skb, int attrtype, 1521 const char *str) 1522{ 1523 return nla_put(skb, attrtype, strlen(str) + 1, str); 1524} 1525 1526/** 1527 * nla_put_flag - Add a flag netlink attribute to a socket buffer 1528 * @skb: socket buffer to add attribute to 1529 * @attrtype: attribute type 1530 */ 1531static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 1532{ 1533 return nla_put(skb, attrtype, 0, NULL); 1534} 1535 1536/** 1537 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it 1538 * @skb: socket buffer to add attribute to 1539 * @attrtype: attribute type 1540 * @njiffies: number of jiffies to convert to msecs 1541 * @padattr: attribute type for the padding 1542 */ 1543static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 1544 unsigned long njiffies, int padattr) 1545{ 1546 u64 tmp = jiffies_to_msecs(njiffies); 1547 1548 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1549} 1550 1551/** 1552 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket 1553 * buffer 1554 * @skb: socket buffer to add attribute to 1555 * @attrtype: attribute type 1556 * @addr: IPv4 address 1557 */ 1558static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype, 1559 __be32 addr) 1560{ 1561 __be32 tmp = addr; 1562 1563 return nla_put_be32(skb, attrtype, tmp); 1564} 1565 1566/** 1567 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket 1568 * buffer 1569 * @skb: socket buffer to add attribute to 1570 * @attrtype: attribute type 1571 * @addr: IPv6 address 1572 */ 1573static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype, 1574 const struct in6_addr *addr) 1575{ 1576 return nla_put(skb, attrtype, sizeof(*addr), addr); 1577} 1578 1579/** 1580 * nla_put_bitfield32 - Add a bitfield32 netlink attribute to a socket buffer 1581 * @skb: socket buffer to add attribute to 1582 * @attrtype: attribute type 1583 * @value: value carrying bits 1584 * @selector: selector of valid bits 1585 */ 1586static inline int nla_put_bitfield32(struct sk_buff *skb, int attrtype, 1587 __u32 value, __u32 selector) 1588{ 1589 struct nla_bitfield32 tmp = { value, selector, }; 1590 1591 return nla_put(skb, attrtype, sizeof(tmp), &tmp); 1592} 1593 1594/** 1595 * nla_get_u32 - return payload of u32 attribute 1596 * @nla: u32 netlink attribute 1597 */ 1598static inline u32 nla_get_u32(const struct nlattr *nla) 1599{ 1600 return *(u32 *) nla_data(nla); 1601} 1602 1603/** 1604 * nla_get_be32 - return payload of __be32 attribute 1605 * @nla: __be32 netlink attribute 1606 */ 1607static inline __be32 nla_get_be32(const struct nlattr *nla) 1608{ 1609 return *(__be32 *) nla_data(nla); 1610} 1611 1612/** 1613 * nla_get_le32 - return payload of __le32 attribute 1614 * @nla: __le32 netlink attribute 1615 */ 1616static inline __le32 nla_get_le32(const struct nlattr *nla) 1617{ 1618 return *(__le32 *) nla_data(nla); 1619} 1620 1621/** 1622 * nla_get_u16 - return payload of u16 attribute 1623 * @nla: u16 netlink attribute 1624 */ 1625static inline u16 nla_get_u16(const struct nlattr *nla) 1626{ 1627 return *(u16 *) nla_data(nla); 1628} 1629 1630/** 1631 * nla_get_be16 - return payload of __be16 attribute 1632 * @nla: __be16 netlink attribute 1633 */ 1634static inline __be16 nla_get_be16(const struct nlattr *nla) 1635{ 1636 return *(__be16 *) nla_data(nla); 1637} 1638 1639/** 1640 * nla_get_le16 - return payload of __le16 attribute 1641 * @nla: __le16 netlink attribute 1642 */ 1643static inline __le16 nla_get_le16(const struct nlattr *nla) 1644{ 1645 return *(__le16 *) nla_data(nla); 1646} 1647 1648/** 1649 * nla_get_u8 - return payload of u8 attribute 1650 * @nla: u8 netlink attribute 1651 */ 1652static inline u8 nla_get_u8(const struct nlattr *nla) 1653{ 1654 return *(u8 *) nla_data(nla); 1655} 1656 1657/** 1658 * nla_get_u64 - return payload of u64 attribute 1659 * @nla: u64 netlink attribute 1660 */ 1661static inline u64 nla_get_u64(const struct nlattr *nla) 1662{ 1663 u64 tmp; 1664 1665 nla_memcpy(&tmp, nla, sizeof(tmp)); 1666 1667 return tmp; 1668} 1669 1670/** 1671 * nla_get_be64 - return payload of __be64 attribute 1672 * @nla: __be64 netlink attribute 1673 */ 1674static inline __be64 nla_get_be64(const struct nlattr *nla) 1675{ 1676 __be64 tmp; 1677 1678 nla_memcpy(&tmp, nla, sizeof(tmp)); 1679 1680 return tmp; 1681} 1682 1683/** 1684 * nla_get_le64 - return payload of __le64 attribute 1685 * @nla: __le64 netlink attribute 1686 */ 1687static inline __le64 nla_get_le64(const struct nlattr *nla) 1688{ 1689 return *(__le64 *) nla_data(nla); 1690} 1691 1692/** 1693 * nla_get_s32 - return payload of s32 attribute 1694 * @nla: s32 netlink attribute 1695 */ 1696static inline s32 nla_get_s32(const struct nlattr *nla) 1697{ 1698 return *(s32 *) nla_data(nla); 1699} 1700 1701/** 1702 * nla_get_s16 - return payload of s16 attribute 1703 * @nla: s16 netlink attribute 1704 */ 1705static inline s16 nla_get_s16(const struct nlattr *nla) 1706{ 1707 return *(s16 *) nla_data(nla); 1708} 1709 1710/** 1711 * nla_get_s8 - return payload of s8 attribute 1712 * @nla: s8 netlink attribute 1713 */ 1714static inline s8 nla_get_s8(const struct nlattr *nla) 1715{ 1716 return *(s8 *) nla_data(nla); 1717} 1718 1719/** 1720 * nla_get_s64 - return payload of s64 attribute 1721 * @nla: s64 netlink attribute 1722 */ 1723static inline s64 nla_get_s64(const struct nlattr *nla) 1724{ 1725 s64 tmp; 1726 1727 nla_memcpy(&tmp, nla, sizeof(tmp)); 1728 1729 return tmp; 1730} 1731 1732/** 1733 * nla_get_flag - return payload of flag attribute 1734 * @nla: flag netlink attribute 1735 */ 1736static inline int nla_get_flag(const struct nlattr *nla) 1737{ 1738 return !!nla; 1739} 1740 1741/** 1742 * nla_get_msecs - return payload of msecs attribute 1743 * @nla: msecs netlink attribute 1744 * 1745 * Returns the number of milliseconds in jiffies. 1746 */ 1747static inline unsigned long nla_get_msecs(const struct nlattr *nla) 1748{ 1749 u64 msecs = nla_get_u64(nla); 1750 1751 return msecs_to_jiffies((unsigned long) msecs); 1752} 1753 1754/** 1755 * nla_get_in_addr - return payload of IPv4 address attribute 1756 * @nla: IPv4 address netlink attribute 1757 */ 1758static inline __be32 nla_get_in_addr(const struct nlattr *nla) 1759{ 1760 return *(__be32 *) nla_data(nla); 1761} 1762 1763/** 1764 * nla_get_in6_addr - return payload of IPv6 address attribute 1765 * @nla: IPv6 address netlink attribute 1766 */ 1767static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla) 1768{ 1769 struct in6_addr tmp; 1770 1771 nla_memcpy(&tmp, nla, sizeof(tmp)); 1772 return tmp; 1773} 1774 1775/** 1776 * nla_get_bitfield32 - return payload of 32 bitfield attribute 1777 * @nla: nla_bitfield32 attribute 1778 */ 1779static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla) 1780{ 1781 struct nla_bitfield32 tmp; 1782 1783 nla_memcpy(&tmp, nla, sizeof(tmp)); 1784 return tmp; 1785} 1786 1787/** 1788 * nla_memdup - duplicate attribute memory (kmemdup) 1789 * @src: netlink attribute to duplicate from 1790 * @gfp: GFP mask 1791 */ 1792static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp) 1793{ 1794 return kmemdup(nla_data(src), nla_len(src), gfp); 1795} 1796 1797/** 1798 * nla_nest_start_noflag - Start a new level of nested attributes 1799 * @skb: socket buffer to add attributes to 1800 * @attrtype: attribute type of container 1801 * 1802 * This function exists for backward compatibility to use in APIs which never 1803 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use 1804 * nla_nest_start() which sets the flag. 1805 * 1806 * Returns the container attribute or NULL on error 1807 */ 1808static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb, 1809 int attrtype) 1810{ 1811 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 1812 1813 if (nla_put(skb, attrtype, 0, NULL) < 0) 1814 return NULL; 1815 1816 return start; 1817} 1818 1819/** 1820 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED 1821 * @skb: socket buffer to add attributes to 1822 * @attrtype: attribute type of container 1823 * 1824 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED 1825 * flag. This is the preferred function to use in new code. 1826 * 1827 * Returns the container attribute or NULL on error 1828 */ 1829static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 1830{ 1831 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED); 1832} 1833 1834/** 1835 * nla_nest_end - Finalize nesting of attributes 1836 * @skb: socket buffer the attributes are stored in 1837 * @start: container attribute 1838 * 1839 * Corrects the container attribute header to include the all 1840 * appeneded attributes. 1841 * 1842 * Returns the total data length of the skb. 1843 */ 1844static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 1845{ 1846 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1847 return skb->len; 1848} 1849 1850/** 1851 * nla_nest_cancel - Cancel nesting of attributes 1852 * @skb: socket buffer the message is stored in 1853 * @start: container attribute 1854 * 1855 * Removes the container attribute and including all nested 1856 * attributes. Returns -EMSGSIZE 1857 */ 1858static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 1859{ 1860 nlmsg_trim(skb, start); 1861} 1862 1863/** 1864 * __nla_validate_nested - Validate a stream of nested attributes 1865 * @start: container attribute 1866 * @maxtype: maximum attribute type to be expected 1867 * @policy: validation policy 1868 * @validate: validation strictness 1869 * @extack: extended ACK report struct 1870 * 1871 * Validates all attributes in the nested attribute stream against the 1872 * specified policy. Attributes with a type exceeding maxtype will be 1873 * ignored. See documenation of struct nla_policy for more details. 1874 * 1875 * Returns 0 on success or a negative error code. 1876 */ 1877static inline int __nla_validate_nested(const struct nlattr *start, int maxtype, 1878 const struct nla_policy *policy, 1879 unsigned int validate, 1880 struct netlink_ext_ack *extack) 1881{ 1882 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy, 1883 validate, extack); 1884} 1885 1886static inline int 1887nla_validate_nested(const struct nlattr *start, int maxtype, 1888 const struct nla_policy *policy, 1889 struct netlink_ext_ack *extack) 1890{ 1891 return __nla_validate_nested(start, maxtype, policy, 1892 NL_VALIDATE_STRICT, extack); 1893} 1894 1895static inline int 1896nla_validate_nested_deprecated(const struct nlattr *start, int maxtype, 1897 const struct nla_policy *policy, 1898 struct netlink_ext_ack *extack) 1899{ 1900 return __nla_validate_nested(start, maxtype, policy, 1901 NL_VALIDATE_LIBERAL, extack); 1902} 1903 1904/** 1905 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute 1906 * @skb: socket buffer the message is stored in 1907 * 1908 * Return true if padding is needed to align the next attribute (nla_data()) to 1909 * a 64-bit aligned area. 1910 */ 1911static inline bool nla_need_padding_for_64bit(struct sk_buff *skb) 1912{ 1913#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 1914 /* The nlattr header is 4 bytes in size, that's why we test 1915 * if the skb->data _is_ aligned. A NOP attribute, plus 1916 * nlattr header for next attribute, will make nla_data() 1917 * 8-byte aligned. 1918 */ 1919 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8)) 1920 return true; 1921#endif 1922 return false; 1923} 1924 1925/** 1926 * nla_align_64bit - 64-bit align the nla_data() of next attribute 1927 * @skb: socket buffer the message is stored in 1928 * @padattr: attribute type for the padding 1929 * 1930 * Conditionally emit a padding netlink attribute in order to make 1931 * the next attribute we emit have a 64-bit aligned nla_data() area. 1932 * This will only be done in architectures which do not have 1933 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined. 1934 * 1935 * Returns zero on success or a negative error code. 1936 */ 1937static inline int nla_align_64bit(struct sk_buff *skb, int padattr) 1938{ 1939 if (nla_need_padding_for_64bit(skb) && 1940 !nla_reserve(skb, padattr, 0)) 1941 return -EMSGSIZE; 1942 1943 return 0; 1944} 1945 1946/** 1947 * nla_total_size_64bit - total length of attribute including padding 1948 * @payload: length of payload 1949 */ 1950static inline int nla_total_size_64bit(int payload) 1951{ 1952 return NLA_ALIGN(nla_attr_size(payload)) 1953#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 1954 + NLA_ALIGN(nla_attr_size(0)) 1955#endif 1956 ; 1957} 1958 1959/** 1960 * nla_for_each_attr - iterate over a stream of attributes 1961 * @pos: loop counter, set to current attribute 1962 * @head: head of attribute stream 1963 * @len: length of attribute stream 1964 * @rem: initialized to len, holds bytes currently remaining in stream 1965 */ 1966#define nla_for_each_attr(pos, head, len, rem) \ 1967 for (pos = head, rem = len; \ 1968 nla_ok(pos, rem); \ 1969 pos = nla_next(pos, &(rem))) 1970 1971/** 1972 * nla_for_each_nested - iterate over nested attributes 1973 * @pos: loop counter, set to current attribute 1974 * @nla: attribute containing the nested attributes 1975 * @rem: initialized to len, holds bytes currently remaining in stream 1976 */ 1977#define nla_for_each_nested(pos, nla, rem) \ 1978 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 1979 1980/** 1981 * nla_is_last - Test if attribute is last in stream 1982 * @nla: attribute to test 1983 * @rem: bytes remaining in stream 1984 */ 1985static inline bool nla_is_last(const struct nlattr *nla, int rem) 1986{ 1987 return nla->nla_len == rem; 1988} 1989 1990void nla_get_range_unsigned(const struct nla_policy *pt, 1991 struct netlink_range_validation *range); 1992void nla_get_range_signed(const struct nla_policy *pt, 1993 struct netlink_range_validation_signed *range); 1994 1995struct netlink_policy_dump_state; 1996 1997int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate, 1998 const struct nla_policy *policy, 1999 unsigned int maxtype); 2000int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
2001 const struct nla_policy *policy, 2002 unsigned int maxtype); 2003bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state); 2004int netlink_policy_dump_write(struct sk_buff *skb, 2005 struct netlink_policy_dump_state *state); 2006void netlink_policy_dump_free(struct netlink_policy_dump_state *state); 2007 2008#endif 2009