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_strlcpy(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 192enum nla_policy_validation { 193 NLA_VALIDATE_NONE, 194 NLA_VALIDATE_RANGE, 195 NLA_VALIDATE_MIN, 196 NLA_VALIDATE_MAX, 197 NLA_VALIDATE_FUNCTION, 198}; 199 200/** 201 * struct nla_policy - attribute validation policy 202 * @type: Type of attribute or NLA_UNSPEC 203 * @validation_type: type of attribute validation done in addition to 204 * type-specific validation (e.g. range, function call), see 205 * &enum nla_policy_validation 206 * @len: Type specific length of payload 207 * 208 * Policies are defined as arrays of this struct, the array must be 209 * accessible by attribute type up to the highest identifier to be expected. 210 * 211 * Meaning of `len' field: 212 * NLA_STRING Maximum length of string 213 * NLA_NUL_STRING Maximum length of string (excluding NUL) 214 * NLA_FLAG Unused 215 * NLA_BINARY Maximum length of attribute payload 216 * NLA_MIN_LEN Minimum length of attribute payload 217 * NLA_NESTED, 218 * NLA_NESTED_ARRAY Length verification is done by checking len of 219 * nested header (or empty); len field is used if 220 * validation_data is also used, for the max attr 221 * number in the nested policy. 222 * NLA_U8, NLA_U16, 223 * NLA_U32, NLA_U64, 224 * NLA_S8, NLA_S16, 225 * NLA_S32, NLA_S64, 226 * NLA_MSECS Leaving the length field zero will verify the 227 * given type fits, using it verifies minimum length 228 * just like "All other" 229 * NLA_BITFIELD32 Unused 230 * NLA_REJECT Unused 231 * NLA_EXACT_LEN Attribute must have exactly this length, otherwise 232 * it is rejected. 233 * NLA_EXACT_LEN_WARN Attribute should have exactly this length, a warning 234 * is logged if it is longer, shorter is rejected. 235 * NLA_MIN_LEN Minimum length of attribute payload 236 * All other Minimum length of attribute payload 237 * 238 * Meaning of `validation_data' field: 239 * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and 240 * validation data must point to a u32 value of valid 241 * flags 242 * NLA_REJECT This attribute is always rejected and validation data 243 * may point to a string to report as the error instead 244 * of the generic one in extended ACK. 245 * NLA_NESTED Points to a nested policy to validate, must also set 246 * `len' to the max attribute number. 247 * Note that nla_parse() will validate, but of course not 248 * parse, the nested sub-policies. 249 * NLA_NESTED_ARRAY Points to a nested policy to validate, must also set 250 * `len' to the max attribute number. The difference to 251 * NLA_NESTED is the structure - NLA_NESTED has the 252 * nested attributes directly inside, while an array has 253 * the nested attributes at another level down and the 254 * attributes directly in the nesting don't matter. 255 * All other Unused - but note that it's a union 256 * 257 * Meaning of `min' and `max' fields, use via NLA_POLICY_MIN, NLA_POLICY_MAX 258 * and NLA_POLICY_RANGE: 259 * NLA_U8, 260 * NLA_U16, 261 * NLA_U32, 262 * NLA_U64, 263 * NLA_S8, 264 * NLA_S16, 265 * NLA_S32, 266 * NLA_S64 These are used depending on the validation_type 267 * field, if that is min/max/range then the minimum, 268 * maximum and both are used (respectively) to check 269 * the value of the integer attribute. 270 * Note that in the interest of code simplicity and 271 * struct size both limits are s16, so you cannot 272 * enforce a range that doesn't fall within the range 273 * of s16 - do that as usual in the code instead. 274 * All other Unused - but note that it's a union 275 * 276 * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN: 277 * NLA_BINARY Validation function called for the attribute, 278 * not compatible with use of the validation_data 279 * as in NLA_BITFIELD32, NLA_REJECT, NLA_NESTED and 280 * NLA_NESTED_ARRAY. 281 * All other Unused - but note that it's a union 282 * 283 * Example: 284 * static const struct nla_policy my_policy[ATTR_MAX+1] = { 285 * [ATTR_FOO] = { .type = NLA_U16 }, 286 * [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ }, 287 * [ATTR_BAZ] = { .type = NLA_EXACT_LEN, .len = sizeof(struct mystruct) }, 288 * [ATTR_GOO] = { .type = NLA_BITFIELD32, .validation_data = &myvalidflags }, 289 * }; 290 */ 291struct nla_policy { 292 u8 type; 293 u8 validation_type; 294 u16 len; 295 union { 296 const void *validation_data; 297 struct { 298 s16 min, max; 299 }; 300 int (*validate)(const struct nlattr *attr, 301 struct netlink_ext_ack *extack); 302 /* This entry is special, and used for the attribute at index 0 303 * only, and specifies special data about the policy, namely it 304 * specifies the "boundary type" where strict length validation 305 * starts for any attribute types >= this value, also, strict 306 * nesting validation starts here. 307 * 308 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT 309 * for any types >= this, so need to use NLA_MIN_LEN to get the 310 * previous pure { .len = xyz } behaviour. The advantage of this 311 * is that types not specified in the policy will be rejected. 312 * 313 * For completely new families it should be set to 1 so that the 314 * validation is enforced for all attributes. For existing ones 315 * it should be set at least when new attributes are added to 316 * the enum used by the policy, and be set to the new value that 317 * was added to enforce strict validation from thereon. 318 */ 319 u16 strict_start_type; 320 }; 321}; 322 323#define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len } 324#define NLA_POLICY_EXACT_LEN_WARN(_len) { .type = NLA_EXACT_LEN_WARN, \ 325 .len = _len } 326#define NLA_POLICY_MIN_LEN(_len) { .type = NLA_MIN_LEN, .len = _len } 327 328#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) 329#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) 330 331#define _NLA_POLICY_NESTED(maxattr, policy) \ 332 { .type = NLA_NESTED, .validation_data = policy, .len = maxattr } 333#define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ 334 { .type = NLA_NESTED_ARRAY, .validation_data = policy, .len = maxattr } 335#define NLA_POLICY_NESTED(policy) \ 336 _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy) 337#define NLA_POLICY_NESTED_ARRAY(policy) \ 338 _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy) 339 340#define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition)) 341#define NLA_ENSURE_INT_TYPE(tp) \ 342 (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 || \ 343 tp == NLA_S16 || tp == NLA_U16 || \ 344 tp == NLA_S32 || tp == NLA_U32 || \ 345 tp == NLA_S64 || tp == NLA_U64) + tp) 346#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \ 347 (__NLA_ENSURE(tp != NLA_BITFIELD32 && \ 348 tp != NLA_REJECT && \ 349 tp != NLA_NESTED && \ 350 tp != NLA_NESTED_ARRAY) + tp) 351 352#define NLA_POLICY_RANGE(tp, _min, _max) { \ 353 .type = NLA_ENSURE_INT_TYPE(tp), \ 354 .validation_type = NLA_VALIDATE_RANGE, \ 355 .min = _min, \ 356 .max = _max \ 357} 358 359#define NLA_POLICY_MIN(tp, _min) { \ 360 .type = NLA_ENSURE_INT_TYPE(tp), \ 361 .validation_type = NLA_VALIDATE_MIN, \ 362 .min = _min, \ 363} 364 365#define NLA_POLICY_MAX(tp, _max) { \ 366 .type = NLA_ENSURE_INT_TYPE(tp), \ 367 .validation_type = NLA_VALIDATE_MAX, \ 368 .max = _max, \ 369} 370 371#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \ 372 .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \ 373 .validation_type = NLA_VALIDATE_FUNCTION, \ 374 .validate = fn, \ 375 .len = __VA_ARGS__ + 0, \ 376} 377 378/** 379 * struct nl_info - netlink source information 380 * @nlh: Netlink message header of original request 381 * @portid: Netlink PORTID of requesting application 382 */ 383struct nl_info { 384 struct nlmsghdr *nlh; 385 struct net *nl_net; 386 u32 portid; 387 bool skip_notify; 388}; 389 390/** 391 * enum netlink_validation - netlink message/attribute validation levels 392 * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about 393 * extra data at the end of the message, attributes being longer than 394 * they should be, or unknown attributes being present. 395 * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing. 396 * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING 397 * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict(). 398 * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy. 399 * This can safely be set by the kernel when the given policy has no 400 * NLA_UNSPEC anymore, and can thus be used to ensure policy entries 401 * are enforced going forward. 402 * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g. 403 * U8, U16, U32 must have exact size, etc.) 404 * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY) 405 * and unset for other policies. 406 */ 407enum netlink_validation { 408 NL_VALIDATE_LIBERAL = 0, 409 NL_VALIDATE_TRAILING = BIT(0), 410 NL_VALIDATE_MAXTYPE = BIT(1), 411 NL_VALIDATE_UNSPEC = BIT(2), 412 NL_VALIDATE_STRICT_ATTRS = BIT(3), 413 NL_VALIDATE_NESTED = BIT(4), 414}; 415 416#define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\ 417 NL_VALIDATE_MAXTYPE) 418#define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\ 419 NL_VALIDATE_MAXTYPE |\ 420 NL_VALIDATE_UNSPEC |\ 421 NL_VALIDATE_STRICT_ATTRS |\ 422 NL_VALIDATE_NESTED) 423 424int netlink_rcv_skb(struct sk_buff *skb, 425 int (*cb)(struct sk_buff *, struct nlmsghdr *, 426 struct netlink_ext_ack *)); 427int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, 428 unsigned int group, int report, gfp_t flags); 429 430int __nla_validate(const struct nlattr *head, int len, int maxtype, 431 const struct nla_policy *policy, unsigned int validate, 432 struct netlink_ext_ack *extack); 433int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, 434 int len, const struct nla_policy *policy, unsigned int validate, 435 struct netlink_ext_ack *extack); 436int nla_policy_len(const struct nla_policy *, int); 437struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype); 438size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize); 439char *nla_strdup(const struct nlattr *nla, gfp_t flags); 440int nla_memcpy(void *dest, const struct nlattr *src, int count); 441int nla_memcmp(const struct nlattr *nla, const void *data, size_t size); 442int nla_strcmp(const struct nlattr *nla, const char *str); 443struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 444struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, 445 int attrlen, int padattr); 446void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 447struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); 448struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, 449 int attrlen, int padattr); 450void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen); 451void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, 452 const void *data); 453void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 454 const void *data, int padattr); 455void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 456int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); 457int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, 458 const void *data, int padattr); 459int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); 460int nla_append(struct sk_buff *skb, int attrlen, const void *data); 461 462/************************************************************************** 463 * Netlink Messages 464 **************************************************************************/ 465 466/** 467 * nlmsg_msg_size - length of netlink message not including padding 468 * @payload: length of message payload 469 */ 470static inline int nlmsg_msg_size(int payload) 471{ 472 return NLMSG_HDRLEN + payload; 473} 474 475/** 476 * nlmsg_total_size - length of netlink message including padding 477 * @payload: length of message payload 478 */ 479static inline int nlmsg_total_size(int payload) 480{ 481 return NLMSG_ALIGN(nlmsg_msg_size(payload)); 482} 483 484/** 485 * nlmsg_padlen - length of padding at the message's tail 486 * @payload: length of message payload 487 */ 488static inline int nlmsg_padlen(int payload) 489{ 490 return nlmsg_total_size(payload) - nlmsg_msg_size(payload); 491} 492 493/** 494 * nlmsg_data - head of message payload 495 * @nlh: netlink message header 496 */ 497static inline void *nlmsg_data(const struct nlmsghdr *nlh) 498{ 499 return (unsigned char *) nlh + NLMSG_HDRLEN; 500} 501 502/** 503 * nlmsg_len - length of message payload 504 * @nlh: netlink message header 505 */ 506static inline int nlmsg_len(const struct nlmsghdr *nlh) 507{ 508 return nlh->nlmsg_len - NLMSG_HDRLEN; 509} 510 511/** 512 * nlmsg_attrdata - head of attributes data 513 * @nlh: netlink message header 514 * @hdrlen: length of family specific header 515 */ 516static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 517 int hdrlen) 518{ 519 unsigned char *data = nlmsg_data(nlh); 520 return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); 521} 522 523/** 524 * nlmsg_attrlen - length of attributes data 525 * @nlh: netlink message header 526 * @hdrlen: length of family specific header 527 */ 528static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) 529{ 530 return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); 531} 532 533/** 534 * nlmsg_ok - check if the netlink message fits into the remaining bytes 535 * @nlh: netlink message header 536 * @remaining: number of bytes remaining in message stream 537 */ 538static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) 539{ 540 return (remaining >= (int) sizeof(struct nlmsghdr) && 541 nlh->nlmsg_len >= sizeof(struct nlmsghdr) && 542 nlh->nlmsg_len <= remaining); 543} 544 545/** 546 * nlmsg_next - next netlink message in message stream 547 * @nlh: netlink message header 548 * @remaining: number of bytes remaining in message stream 549 * 550 * Returns the next netlink message in the message stream and 551 * decrements remaining by the size of the current message. 552 */ 553static inline struct nlmsghdr * 554nlmsg_next(const struct nlmsghdr *nlh, int *remaining) 555{ 556 int totlen = NLMSG_ALIGN(nlh->nlmsg_len); 557 558 *remaining -= totlen; 559 560 return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); 561} 562 563/** 564 * nla_parse - Parse a stream of attributes into a tb buffer 565 * @tb: destination array with maxtype+1 elements 566 * @maxtype: maximum attribute type to be expected 567 * @head: head of attribute stream 568 * @len: length of attribute stream 569 * @policy: validation policy 570 * @extack: extended ACK pointer 571 * 572 * Parses a stream of attributes and stores a pointer to each attribute in 573 * the tb array accessible via the attribute type. Attributes with a type 574 * exceeding maxtype will be rejected, policy must be specified, attributes 575 * will be validated in the strictest way possible. 576 * 577 * Returns 0 on success or a negative error code. 578 */ 579static inline int nla_parse(struct nlattr **tb, int maxtype, 580 const struct nlattr *head, int len, 581 const struct nla_policy *policy, 582 struct netlink_ext_ack *extack) 583{ 584 return __nla_parse(tb, maxtype, head, len, policy, 585 NL_VALIDATE_STRICT, extack); 586} 587 588/** 589 * nla_parse_deprecated - Parse a stream of attributes into a tb buffer 590 * @tb: destination array with maxtype+1 elements 591 * @maxtype: maximum attribute type to be expected 592 * @head: head of attribute stream 593 * @len: length of attribute stream 594 * @policy: validation policy 595 * @extack: extended ACK pointer 596 * 597 * Parses a stream of attributes and stores a pointer to each attribute in 598 * the tb array accessible via the attribute type. Attributes with a type 599 * exceeding maxtype will be ignored and attributes from the policy are not 600 * always strictly validated (only for new attributes). 601 * 602 * Returns 0 on success or a negative error code. 603 */ 604static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype, 605 const struct nlattr *head, int len, 606 const struct nla_policy *policy, 607 struct netlink_ext_ack *extack) 608{ 609 return __nla_parse(tb, maxtype, head, len, policy, 610 NL_VALIDATE_LIBERAL, extack); 611} 612 613/** 614 * nla_parse_deprecated_strict - Parse a stream of attributes into a tb buffer 615 * @tb: destination array with maxtype+1 elements 616 * @maxtype: maximum attribute type to be expected 617 * @head: head of attribute stream 618 * @len: length of attribute stream 619 * @policy: validation policy 620 * @extack: extended ACK pointer 621 * 622 * Parses a stream of attributes and stores a pointer to each attribute in 623 * the tb array accessible via the attribute type. Attributes with a type 624 * exceeding maxtype will be rejected as well as trailing data, but the 625 * policy is not completely strictly validated (only for new attributes). 626 * 627 * Returns 0 on success or a negative error code. 628 */ 629static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype, 630 const struct nlattr *head, 631 int len, 632 const struct nla_policy *policy, 633 struct netlink_ext_ack *extack) 634{ 635 return __nla_parse(tb, maxtype, head, len, policy, 636 NL_VALIDATE_DEPRECATED_STRICT, extack); 637} 638 639/** 640 * __nlmsg_parse - parse attributes of a netlink message 641 * @nlh: netlink message header 642 * @hdrlen: length of family specific header 643 * @tb: destination array with maxtype+1 elements 644 * @maxtype: maximum attribute type to be expected 645 * @policy: validation policy 646 * @validate: validation strictness 647 * @extack: extended ACK report struct 648 * 649 * See nla_parse() 650 */ 651static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 652 struct nlattr *tb[], int maxtype, 653 const struct nla_policy *policy, 654 unsigned int validate, 655 struct netlink_ext_ack *extack) 656{ 657 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) { 658 NL_SET_ERR_MSG(extack, "Invalid header length"); 659 return -EINVAL; 660 } 661 662 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 663 nlmsg_attrlen(nlh, hdrlen), policy, validate, 664 extack); 665} 666 667/** 668 * nlmsg_parse - parse attributes of a netlink message 669 * @nlh: netlink message header 670 * @hdrlen: length of family specific header 671 * @tb: destination array with maxtype+1 elements 672 * @maxtype: maximum attribute type to be expected 673 * @validate: validation strictness 674 * @extack: extended ACK report struct 675 * 676 * See nla_parse() 677 */ 678static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, 679 struct nlattr *tb[], int maxtype, 680 const struct nla_policy *policy, 681 struct netlink_ext_ack *extack) 682{ 683 return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), 684 nlmsg_attrlen(nlh, hdrlen), policy, 685 NL_VALIDATE_STRICT, extack); 686} 687 688/** 689 * nlmsg_parse_deprecated - parse attributes of a netlink message 690 * @nlh: netlink message header 691 * @hdrlen: length of family specific header 692 * @tb: destination array with maxtype+1 elements 693 * @maxtype: maximum attribute type to be expected 694 * @extack: extended ACK report struct 695 * 696 * See nla_parse_deprecated() 697 */ 698static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen, 699 struct nlattr *tb[], int maxtype, 700 const struct nla_policy *policy, 701 struct netlink_ext_ack *extack) 702{ 703 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 704 NL_VALIDATE_LIBERAL, extack); 705} 706 707/** 708 * nlmsg_parse_deprecated_strict - parse attributes of a netlink message 709 * @nlh: netlink message header 710 * @hdrlen: length of family specific header 711 * @tb: destination array with maxtype+1 elements 712 * @maxtype: maximum attribute type to be expected 713 * @extack: extended ACK report struct 714 * 715 * See nla_parse_deprecated_strict() 716 */ 717static inline int 718nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen, 719 struct nlattr *tb[], int maxtype, 720 const struct nla_policy *policy, 721 struct netlink_ext_ack *extack) 722{ 723 return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, 724 NL_VALIDATE_DEPRECATED_STRICT, extack); 725} 726 727/** 728 * nlmsg_find_attr - find a specific attribute in a netlink message 729 * @nlh: netlink message header 730 * @hdrlen: length of familiy specific header 731 * @attrtype: type of attribute to look for 732 * 733 * Returns the first attribute which matches the specified type. 734 */ 735static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh, 736 int hdrlen, int attrtype) 737{ 738 return nla_find(nlmsg_attrdata(nlh, hdrlen), 739 nlmsg_attrlen(nlh, hdrlen), attrtype); 740} 741 742/** 743 * nla_validate_deprecated - Validate a stream of attributes 744 * @head: head of attribute stream 745 * @len: length of attribute stream 746 * @maxtype: maximum attribute type to be expected 747 * @policy: validation policy 748 * @validate: validation strictness 749 * @extack: extended ACK report struct 750 * 751 * Validates all attributes in the specified attribute stream against the 752 * specified policy. Validation is done in liberal mode. 753 * See documenation of struct nla_policy for more details. 754 * 755 * Returns 0 on success or a negative error code. 756 */ 757static inline int nla_validate_deprecated(const struct nlattr *head, int len, 758 int maxtype, 759 const struct nla_policy *policy, 760 struct netlink_ext_ack *extack) 761{ 762 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL, 763 extack); 764} 765 766/** 767 * nla_validate - Validate a stream of attributes 768 * @head: head of attribute stream 769 * @len: length of attribute stream 770 * @maxtype: maximum attribute type to be expected 771 * @policy: validation policy 772 * @validate: validation strictness 773 * @extack: extended ACK report struct 774 * 775 * Validates all attributes in the specified attribute stream against the 776 * specified policy. Validation is done in strict mode. 777 * See documenation of struct nla_policy for more details. 778 * 779 * Returns 0 on success or a negative error code. 780 */ 781static inline int nla_validate(const struct nlattr *head, int len, int maxtype, 782 const struct nla_policy *policy, 783 struct netlink_ext_ack *extack) 784{ 785 return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT, 786 extack); 787} 788 789/** 790 * nlmsg_validate_deprecated - validate a netlink message including attributes 791 * @nlh: netlinket message header 792 * @hdrlen: length of familiy specific header 793 * @maxtype: maximum attribute type to be expected 794 * @policy: validation policy 795 * @extack: extended ACK report struct 796 */ 797static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh, 798 int hdrlen, int maxtype, 799 const struct nla_policy *policy, 800 struct netlink_ext_ack *extack) 801{ 802 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) 803 return -EINVAL; 804 805 return __nla_validate(nlmsg_attrdata(nlh, hdrlen), 806 nlmsg_attrlen(nlh, hdrlen), maxtype, 807 policy, NL_VALIDATE_LIBERAL, extack); 808} 809 810 811 812/** 813 * nlmsg_report - need to report back to application? 814 * @nlh: netlink message header 815 * 816 * Returns 1 if a report back to the application is requested. 817 */ 818static inline int nlmsg_report(const struct nlmsghdr *nlh) 819{ 820 return !!(nlh->nlmsg_flags & NLM_F_ECHO); 821} 822 823/** 824 * nlmsg_for_each_attr - iterate over a stream of attributes 825 * @pos: loop counter, set to current attribute 826 * @nlh: netlink message header 827 * @hdrlen: length of familiy specific header 828 * @rem: initialized to len, holds bytes currently remaining in stream 829 */ 830#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ 831 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ 832 nlmsg_attrlen(nlh, hdrlen), rem) 833 834/** 835 * nlmsg_put - Add a new netlink message to an skb 836 * @skb: socket buffer to store message in 837 * @portid: netlink PORTID of requesting application 838 * @seq: sequence number of message 839 * @type: message type 840 * @payload: length of message payload 841 * @flags: message flags 842 * 843 * Returns NULL if the tailroom of the skb is insufficient to store 844 * the message header and payload. 845 */ 846static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, 847 int type, int payload, int flags) 848{ 849 if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) 850 return NULL; 851 852 return __nlmsg_put(skb, portid, seq, type, payload, flags); 853} 854 855/** 856 * nlmsg_put_answer - Add a new callback based netlink message to an skb 857 * @skb: socket buffer to store message in 858 * @cb: netlink callback 859 * @type: message type 860 * @payload: length of message payload 861 * @flags: message flags 862 * 863 * Returns NULL if the tailroom of the skb is insufficient to store 864 * the message header and payload. 865 */ 866static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, 867 struct netlink_callback *cb, 868 int type, int payload, 869 int flags) 870{ 871 return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 872 type, payload, flags); 873} 874 875/** 876 * nlmsg_new - Allocate a new netlink message 877 * @payload: size of the message payload 878 * @flags: the type of memory to allocate. 879 * 880 * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known 881 * and a good default is needed. 882 */ 883static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) 884{ 885 return alloc_skb(nlmsg_total_size(payload), flags); 886} 887 888/** 889 * nlmsg_end - Finalize a netlink message 890 * @skb: socket buffer the message is stored in 891 * @nlh: netlink message header 892 * 893 * Corrects the netlink message header to include the appeneded 894 * attributes. Only necessary if attributes have been added to 895 * the message. 896 */ 897static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) 898{ 899 nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; 900} 901 902/** 903 * nlmsg_get_pos - return current position in netlink message 904 * @skb: socket buffer the message is stored in 905 * 906 * Returns a pointer to the current tail of the message. 907 */ 908static inline void *nlmsg_get_pos(struct sk_buff *skb) 909{ 910 return skb_tail_pointer(skb); 911} 912 913/** 914 * nlmsg_trim - Trim message to a mark 915 * @skb: socket buffer the message is stored in 916 * @mark: mark to trim to 917 * 918 * Trims the message to the provided mark. 919 */ 920static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) 921{ 922 if (mark) { 923 WARN_ON((unsigned char *) mark < skb->data); 924 skb_trim(skb, (unsigned char *) mark - skb->data); 925 } 926} 927 928/** 929 * nlmsg_cancel - Cancel construction of a netlink message 930 * @skb: socket buffer the message is stored in 931 * @nlh: netlink message header 932 * 933 * Removes the complete netlink message including all 934 * attributes from the socket buffer again. 935 */ 936static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) 937{ 938 nlmsg_trim(skb, nlh); 939} 940 941/** 942 * nlmsg_free - free a netlink message 943 * @skb: socket buffer of netlink message 944 */ 945static inline void nlmsg_free(struct sk_buff *skb) 946{ 947 kfree_skb(skb); 948} 949 950/** 951 * nlmsg_multicast - multicast a netlink message 952 * @sk: netlink socket to spread messages to 953 * @skb: netlink message as socket buffer 954 * @portid: own netlink portid to avoid sending to yourself 955 * @group: multicast group id 956 * @flags: allocation flags 957 */ 958static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, 959 u32 portid, unsigned int group, gfp_t flags) 960{ 961 int err; 962 963 NETLINK_CB(skb).dst_group = group; 964 965 err = netlink_broadcast(sk, skb, portid, group, flags); 966 if (err > 0) 967 err = 0; 968 969 return err; 970} 971 972/** 973 * nlmsg_unicast - unicast a netlink message 974 * @sk: netlink socket to spread message to 975 * @skb: netlink message as socket buffer 976 * @portid: netlink portid of the destination socket 977 */ 978static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid) 979{ 980 int err; 981 982 err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT); 983 if (err > 0) 984 err = 0; 985 986 return err; 987} 988 989/** 990 * nlmsg_for_each_msg - iterate over a stream of messages 991 * @pos: loop counter, set to current message 992 * @head: head of message stream 993 * @len: length of message stream 994 * @rem: initialized to len, holds bytes currently remaining in stream 995 */ 996#define nlmsg_for_each_msg(pos, head, len, rem) \ 997 for (pos = head, rem = len; \ 998 nlmsg_ok(pos, rem); \ 999 pos = nlmsg_next(pos, &(rem))) 1000
1001/** 1002 * nl_dump_check_consistent - check if sequence is consistent and advertise if not 1003 * @cb: netlink callback structure that stores the sequence number 1004 * @nlh: netlink message header to write the flag to 1005 * 1006 * This function checks if the sequence (generation) number changed during dump 1007 * and if it did, advertises it in the netlink message header. 1008 * 1009 * The correct way to use it is to set cb->seq to the generation counter when 1010 * all locks for dumping have been acquired, and then call this function for 1011 * each message that is generated. 1012 * 1013 * Note that due to initialisation concerns, 0 is an invalid sequence number 1014 * and must not be used by code that uses this functionality. 1015 */ 1016static inline void 1017nl_dump_check_consistent(struct netlink_callback *cb, 1018 struct nlmsghdr *nlh) 1019{ 1020 if (cb->prev_seq && cb->seq != cb->prev_seq) 1021 nlh->nlmsg_flags |= NLM_F_DUMP_INTR; 1022 cb->prev_seq = cb->seq; 1023} 1024 1025/************************************************************************** 1026 * Netlink Attributes 1027 **************************************************************************/ 1028 1029/** 1030 * nla_attr_size - length of attribute not including padding 1031 * @payload: length of payload 1032 */ 1033static inline int nla_attr_size(int payload) 1034{ 1035 return NLA_HDRLEN + payload; 1036} 1037 1038/** 1039 * nla_total_size - total length of attribute including padding 1040 * @payload: length of payload 1041 */ 1042static inline int nla_total_size(int payload) 1043{ 1044 return NLA_ALIGN(nla_attr_size(payload)); 1045} 1046 1047/** 1048 * nla_padlen - length of padding at the tail of attribute 1049 * @payload: length of payload 1050 */ 1051static inline int nla_padlen(int payload) 1052{ 1053 return nla_total_size(payload) - nla_attr_size(payload); 1054} 1055 1056/** 1057 * nla_type - attribute type 1058 * @nla: netlink attribute 1059 */ 1060static inline int nla_type(const struct nlattr *nla) 1061{ 1062 return nla->nla_type & NLA_TYPE_MASK; 1063} 1064 1065/** 1066 * nla_data - head of payload 1067 * @nla: netlink attribute 1068 */ 1069static inline void *nla_data(const struct nlattr *nla) 1070{ 1071 return (char *) nla + NLA_HDRLEN; 1072} 1073 1074/** 1075 * nla_len - length of payload 1076 * @nla: netlink attribute 1077 */ 1078static inline int nla_len(const struct nlattr *nla) 1079{ 1080 return nla->nla_len - NLA_HDRLEN; 1081} 1082 1083/** 1084 * nla_ok - check if the netlink attribute fits into the remaining bytes 1085 * @nla: netlink attribute 1086 * @remaining: number of bytes remaining in attribute stream 1087 */ 1088static inline int nla_ok(const struct nlattr *nla, int remaining) 1089{ 1090 return remaining >= (int) sizeof(*nla) && 1091 nla->nla_len >= sizeof(*nla) && 1092 nla->nla_len <= remaining; 1093} 1094 1095/** 1096 * nla_next - next netlink attribute in attribute stream 1097 * @nla: netlink attribute 1098 * @remaining: number of bytes remaining in attribute stream 1099 * 1100 * Returns the next netlink attribute in the attribute stream and 1101 * decrements remaining by the size of the current attribute. 1102 */ 1103static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) 1104{ 1105 unsigned int totlen = NLA_ALIGN(nla->nla_len); 1106 1107 *remaining -= totlen; 1108 return (struct nlattr *) ((char *) nla + totlen); 1109} 1110 1111/** 1112 * nla_find_nested - find attribute in a set of nested attributes 1113 * @nla: attribute containing the nested attributes 1114 * @attrtype: type of attribute to look for 1115 * 1116 * Returns the first attribute which matches the specified type. 1117 */ 1118static inline struct nlattr * 1119nla_find_nested(const struct nlattr *nla, int attrtype) 1120{ 1121 return nla_find(nla_data(nla), nla_len(nla), attrtype); 1122} 1123 1124/** 1125 * nla_parse_nested - parse nested attributes 1126 * @tb: destination array with maxtype+1 elements 1127 * @maxtype: maximum attribute type to be expected 1128 * @nla: attribute containing the nested attributes 1129 * @policy: validation policy 1130 * @extack: extended ACK report struct 1131 * 1132 * See nla_parse() 1133 */ 1134static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, 1135 const struct nlattr *nla, 1136 const struct nla_policy *policy, 1137 struct netlink_ext_ack *extack) 1138{ 1139 if (!(nla->nla_type & NLA_F_NESTED)) { 1140 NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing"); 1141 return -EINVAL; 1142 } 1143 1144 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, 1145 NL_VALIDATE_STRICT, extack); 1146} 1147 1148/** 1149 * nla_parse_nested_deprecated - parse nested attributes 1150 * @tb: destination array with maxtype+1 elements 1151 * @maxtype: maximum attribute type to be expected 1152 * @nla: attribute containing the nested attributes 1153 * @policy: validation policy 1154 * @extack: extended ACK report struct 1155 * 1156 * See nla_parse_deprecated() 1157 */ 1158static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype, 1159 const struct nlattr *nla, 1160 const struct nla_policy *policy, 1161 struct netlink_ext_ack *extack) 1162{ 1163 return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, 1164 NL_VALIDATE_LIBERAL, extack); 1165} 1166 1167/** 1168 * nla_put_u8 - Add a u8 netlink attribute to a socket buffer 1169 * @skb: socket buffer to add attribute to 1170 * @attrtype: attribute type 1171 * @value: numeric value 1172 */ 1173static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) 1174{ 1175 /* temporary variables to work around GCC PR81715 with asan-stack=1 */ 1176 u8 tmp = value; 1177 1178 return nla_put(skb, attrtype, sizeof(u8), &tmp); 1179} 1180 1181/** 1182 * nla_put_u16 - Add a u16 netlink attribute to a socket buffer 1183 * @skb: socket buffer to add attribute to 1184 * @attrtype: attribute type 1185 * @value: numeric value 1186 */ 1187static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) 1188{ 1189 u16 tmp = value; 1190 1191 return nla_put(skb, attrtype, sizeof(u16), &tmp); 1192} 1193 1194/** 1195 * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer 1196 * @skb: socket buffer to add attribute to 1197 * @attrtype: attribute type 1198 * @value: numeric value 1199 */ 1200static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value) 1201{ 1202 __be16 tmp = value; 1203 1204 return nla_put(skb, attrtype, sizeof(__be16), &tmp); 1205} 1206 1207/** 1208 * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer 1209 * @skb: socket buffer to add attribute to 1210 * @attrtype: attribute type 1211 * @value: numeric value 1212 */ 1213static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value) 1214{ 1215 __be16 tmp = value; 1216 1217 return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 1218} 1219 1220/** 1221 * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer 1222 * @skb: socket buffer to add attribute to 1223 * @attrtype: attribute type 1224 * @value: numeric value 1225 */ 1226static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value) 1227{ 1228 __le16 tmp = value; 1229 1230 return nla_put(skb, attrtype, sizeof(__le16), &tmp); 1231} 1232 1233/** 1234 * nla_put_u32 - Add a u32 netlink attribute to a socket buffer 1235 * @skb: socket buffer to add attribute to 1236 * @attrtype: attribute type 1237 * @value: numeric value 1238 */ 1239static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) 1240{ 1241 u32 tmp = value; 1242 1243 return nla_put(skb, attrtype, sizeof(u32), &tmp); 1244} 1245 1246/** 1247 * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer 1248 * @skb: socket buffer to add attribute to 1249 * @attrtype: attribute type 1250 * @value: numeric value 1251 */ 1252static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value) 1253{ 1254 __be32 tmp = value; 1255 1256 return nla_put(skb, attrtype, sizeof(__be32), &tmp); 1257} 1258 1259/** 1260 * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer 1261 * @skb: socket buffer to add attribute to 1262 * @attrtype: attribute type 1263 * @value: numeric value 1264 */ 1265static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value) 1266{ 1267 __be32 tmp = value; 1268 1269 return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); 1270} 1271 1272/** 1273 * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer 1274 * @skb: socket buffer to add attribute to 1275 * @attrtype: attribute type 1276 * @value: numeric value 1277 */ 1278static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value) 1279{ 1280 __le32 tmp = value; 1281 1282 return nla_put(skb, attrtype, sizeof(__le32), &tmp); 1283} 1284 1285/** 1286 * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it 1287 * @skb: socket buffer to add attribute to 1288 * @attrtype: attribute type 1289 * @value: numeric value 1290 * @padattr: attribute type for the padding 1291 */ 1292static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype, 1293 u64 value, int padattr) 1294{ 1295 u64 tmp = value; 1296 1297 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1298} 1299 1300/** 1301 * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it 1302 * @skb: socket buffer to add attribute to 1303 * @attrtype: attribute type 1304 * @value: numeric value 1305 * @padattr: attribute type for the padding 1306 */ 1307static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value, 1308 int padattr) 1309{ 1310 __be64 tmp = value; 1311 1312 return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr); 1313} 1314 1315/** 1316 * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it 1317 * @skb: socket buffer to add attribute to 1318 * @attrtype: attribute type 1319 * @value: numeric value 1320 * @padattr: attribute type for the padding 1321 */ 1322static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value, 1323 int padattr) 1324{ 1325 __be64 tmp = value; 1326 1327 return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp, 1328 padattr); 1329} 1330 1331/** 1332 * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it 1333 * @skb: socket buffer to add attribute to 1334 * @attrtype: attribute type 1335 * @value: numeric value 1336 * @padattr: attribute type for the padding 1337 */ 1338static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value, 1339 int padattr) 1340{ 1341 __le64 tmp = value; 1342 1343 return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr); 1344} 1345 1346/** 1347 * nla_put_s8 - Add a s8 netlink attribute to a socket buffer 1348 * @skb: socket buffer to add attribute to 1349 * @attrtype: attribute type 1350 * @value: numeric value 1351 */ 1352static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value) 1353{ 1354 s8 tmp = value; 1355 1356 return nla_put(skb, attrtype, sizeof(s8), &tmp); 1357} 1358 1359/** 1360 * nla_put_s16 - Add a s16 netlink attribute to a socket buffer 1361 * @skb: socket buffer to add attribute to 1362 * @attrtype: attribute type 1363 * @value: numeric value 1364 */ 1365static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value) 1366{ 1367 s16 tmp = value; 1368 1369 return nla_put(skb, attrtype, sizeof(s16), &tmp); 1370} 1371 1372/** 1373 * nla_put_s32 - Add a s32 netlink attribute to a socket buffer 1374 * @skb: socket buffer to add attribute to 1375 * @attrtype: attribute type 1376 * @value: numeric value 1377 */ 1378static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value) 1379{ 1380 s32 tmp = value; 1381 1382 return nla_put(skb, attrtype, sizeof(s32), &tmp); 1383} 1384 1385/** 1386 * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it 1387 * @skb: socket buffer to add attribute to 1388 * @attrtype: attribute type 1389 * @value: numeric value 1390 * @padattr: attribute type for the padding 1391 */ 1392static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value, 1393 int padattr) 1394{ 1395 s64 tmp = value; 1396 1397 return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr); 1398} 1399 1400/** 1401 * nla_put_string - Add a string netlink attribute to a socket buffer 1402 * @skb: socket buffer to add attribute to 1403 * @attrtype: attribute type 1404 * @str: NUL terminated string 1405 */ 1406static inline int nla_put_string(struct sk_buff *skb, int attrtype, 1407 const char *str) 1408{ 1409 return nla_put(skb, attrtype, strlen(str) + 1, str); 1410} 1411 1412/** 1413 * nla_put_flag - Add a flag netlink attribute to a socket buffer 1414 * @skb: socket buffer to add attribute to 1415 * @attrtype: attribute type 1416 */ 1417static inline int nla_put_flag(struct sk_buff *skb, int attrtype) 1418{ 1419 return nla_put(skb, attrtype, 0, NULL); 1420} 1421 1422/** 1423 * nla_put_msecs - Add a msecs netlink attribute to a skb and align it 1424 * @skb: socket buffer to add attribute to 1425 * @attrtype: attribute type 1426 * @njiffies: number of jiffies to convert to msecs 1427 * @padattr: attribute type for the padding 1428 */ 1429static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, 1430 unsigned long njiffies, int padattr) 1431{ 1432 u64 tmp = jiffies_to_msecs(njiffies); 1433 1434 return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); 1435} 1436 1437/** 1438 * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket 1439 * buffer 1440 * @skb: socket buffer to add attribute to 1441 * @attrtype: attribute type 1442 * @addr: IPv4 address 1443 */ 1444static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype, 1445 __be32 addr) 1446{ 1447 __be32 tmp = addr; 1448 1449 return nla_put_be32(skb, attrtype, tmp); 1450} 1451 1452/** 1453 * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket 1454 * buffer 1455 * @skb: socket buffer to add attribute to 1456 * @attrtype: attribute type 1457 * @addr: IPv6 address 1458 */ 1459static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype, 1460 const struct in6_addr *addr) 1461{ 1462 return nla_put(skb, attrtype, sizeof(*addr), addr); 1463} 1464 1465/** 1466 * nla_get_u32 - return payload of u32 attribute 1467 * @nla: u32 netlink attribute 1468 */ 1469static inline u32 nla_get_u32(const struct nlattr *nla) 1470{ 1471 return *(u32 *) nla_data(nla); 1472} 1473 1474/** 1475 * nla_get_be32 - return payload of __be32 attribute 1476 * @nla: __be32 netlink attribute 1477 */ 1478static inline __be32 nla_get_be32(const struct nlattr *nla) 1479{ 1480 return *(__be32 *) nla_data(nla); 1481} 1482 1483/** 1484 * nla_get_le32 - return payload of __le32 attribute 1485 * @nla: __le32 netlink attribute 1486 */ 1487static inline __le32 nla_get_le32(const struct nlattr *nla) 1488{ 1489 return *(__le32 *) nla_data(nla); 1490} 1491 1492/** 1493 * nla_get_u16 - return payload of u16 attribute 1494 * @nla: u16 netlink attribute 1495 */ 1496static inline u16 nla_get_u16(const struct nlattr *nla) 1497{ 1498 return *(u16 *) nla_data(nla); 1499} 1500 1501/** 1502 * nla_get_be16 - return payload of __be16 attribute 1503 * @nla: __be16 netlink attribute 1504 */ 1505static inline __be16 nla_get_be16(const struct nlattr *nla) 1506{ 1507 return *(__be16 *) nla_data(nla); 1508} 1509 1510/** 1511 * nla_get_le16 - return payload of __le16 attribute 1512 * @nla: __le16 netlink attribute 1513 */ 1514static inline __le16 nla_get_le16(const struct nlattr *nla) 1515{ 1516 return *(__le16 *) nla_data(nla); 1517} 1518 1519/** 1520 * nla_get_u8 - return payload of u8 attribute 1521 * @nla: u8 netlink attribute 1522 */ 1523static inline u8 nla_get_u8(const struct nlattr *nla) 1524{ 1525 return *(u8 *) nla_data(nla); 1526} 1527 1528/** 1529 * nla_get_u64 - return payload of u64 attribute 1530 * @nla: u64 netlink attribute 1531 */ 1532static inline u64 nla_get_u64(const struct nlattr *nla) 1533{ 1534 u64 tmp; 1535 1536 nla_memcpy(&tmp, nla, sizeof(tmp)); 1537 1538 return tmp; 1539} 1540 1541/** 1542 * nla_get_be64 - return payload of __be64 attribute 1543 * @nla: __be64 netlink attribute 1544 */ 1545static inline __be64 nla_get_be64(const struct nlattr *nla) 1546{ 1547 __be64 tmp; 1548 1549 nla_memcpy(&tmp, nla, sizeof(tmp)); 1550 1551 return tmp; 1552} 1553 1554/** 1555 * nla_get_le64 - return payload of __le64 attribute 1556 * @nla: __le64 netlink attribute 1557 */ 1558static inline __le64 nla_get_le64(const struct nlattr *nla) 1559{ 1560 return *(__le64 *) nla_data(nla); 1561} 1562 1563/** 1564 * nla_get_s32 - return payload of s32 attribute 1565 * @nla: s32 netlink attribute 1566 */ 1567static inline s32 nla_get_s32(const struct nlattr *nla) 1568{ 1569 return *(s32 *) nla_data(nla); 1570} 1571 1572/** 1573 * nla_get_s16 - return payload of s16 attribute 1574 * @nla: s16 netlink attribute 1575 */ 1576static inline s16 nla_get_s16(const struct nlattr *nla) 1577{ 1578 return *(s16 *) nla_data(nla); 1579} 1580 1581/** 1582 * nla_get_s8 - return payload of s8 attribute 1583 * @nla: s8 netlink attribute 1584 */ 1585static inline s8 nla_get_s8(const struct nlattr *nla) 1586{ 1587 return *(s8 *) nla_data(nla); 1588} 1589 1590/** 1591 * nla_get_s64 - return payload of s64 attribute 1592 * @nla: s64 netlink attribute 1593 */ 1594static inline s64 nla_get_s64(const struct nlattr *nla) 1595{ 1596 s64 tmp; 1597 1598 nla_memcpy(&tmp, nla, sizeof(tmp)); 1599 1600 return tmp; 1601} 1602 1603/** 1604 * nla_get_flag - return payload of flag attribute 1605 * @nla: flag netlink attribute 1606 */ 1607static inline int nla_get_flag(const struct nlattr *nla) 1608{ 1609 return !!nla; 1610} 1611 1612/** 1613 * nla_get_msecs - return payload of msecs attribute 1614 * @nla: msecs netlink attribute 1615 * 1616 * Returns the number of milliseconds in jiffies. 1617 */ 1618static inline unsigned long nla_get_msecs(const struct nlattr *nla) 1619{ 1620 u64 msecs = nla_get_u64(nla); 1621 1622 return msecs_to_jiffies((unsigned long) msecs); 1623} 1624 1625/** 1626 * nla_get_in_addr - return payload of IPv4 address attribute 1627 * @nla: IPv4 address netlink attribute 1628 */ 1629static inline __be32 nla_get_in_addr(const struct nlattr *nla) 1630{ 1631 return *(__be32 *) nla_data(nla); 1632} 1633 1634/** 1635 * nla_get_in6_addr - return payload of IPv6 address attribute 1636 * @nla: IPv6 address netlink attribute 1637 */ 1638static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla) 1639{ 1640 struct in6_addr tmp; 1641 1642 nla_memcpy(&tmp, nla, sizeof(tmp)); 1643 return tmp; 1644} 1645 1646/** 1647 * nla_get_bitfield32 - return payload of 32 bitfield attribute 1648 * @nla: nla_bitfield32 attribute 1649 */ 1650static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla) 1651{ 1652 struct nla_bitfield32 tmp; 1653 1654 nla_memcpy(&tmp, nla, sizeof(tmp)); 1655 return tmp; 1656} 1657 1658/** 1659 * nla_memdup - duplicate attribute memory (kmemdup) 1660 * @src: netlink attribute to duplicate from 1661 * @gfp: GFP mask 1662 */ 1663static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp) 1664{ 1665 return kmemdup(nla_data(src), nla_len(src), gfp); 1666} 1667 1668/** 1669 * nla_nest_start_noflag - Start a new level of nested attributes 1670 * @skb: socket buffer to add attributes to 1671 * @attrtype: attribute type of container 1672 * 1673 * This function exists for backward compatibility to use in APIs which never 1674 * marked their nest attributes with NLA_F_NESTED flag. New APIs should use 1675 * nla_nest_start() which sets the flag. 1676 * 1677 * Returns the container attribute or NULL on error 1678 */ 1679static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb, 1680 int attrtype) 1681{ 1682 struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); 1683 1684 if (nla_put(skb, attrtype, 0, NULL) < 0) 1685 return NULL; 1686 1687 return start; 1688} 1689 1690/** 1691 * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED 1692 * @skb: socket buffer to add attributes to 1693 * @attrtype: attribute type of container 1694 * 1695 * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED 1696 * flag. This is the preferred function to use in new code. 1697 * 1698 * Returns the container attribute or NULL on error 1699 */ 1700static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) 1701{ 1702 return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED); 1703} 1704 1705/** 1706 * nla_nest_end - Finalize nesting of attributes 1707 * @skb: socket buffer the attributes are stored in 1708 * @start: container attribute 1709 * 1710 * Corrects the container attribute header to include the all 1711 * appeneded attributes. 1712 * 1713 * Returns the total data length of the skb. 1714 */ 1715static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) 1716{ 1717 start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; 1718 return skb->len; 1719} 1720 1721/** 1722 * nla_nest_cancel - Cancel nesting of attributes 1723 * @skb: socket buffer the message is stored in 1724 * @start: container attribute 1725 * 1726 * Removes the container attribute and including all nested 1727 * attributes. Returns -EMSGSIZE 1728 */ 1729static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) 1730{ 1731 nlmsg_trim(skb, start); 1732} 1733 1734/** 1735 * nla_validate_nested - Validate a stream of nested attributes 1736 * @start: container attribute 1737 * @maxtype: maximum attribute type to be expected 1738 * @policy: validation policy 1739 * @validate: validation strictness 1740 * @extack: extended ACK report struct 1741 * 1742 * Validates all attributes in the nested attribute stream against the 1743 * specified policy. Attributes with a type exceeding maxtype will be 1744 * ignored. See documenation of struct nla_policy for more details. 1745 * 1746 * Returns 0 on success or a negative error code. 1747 */ 1748static inline int __nla_validate_nested(const struct nlattr *start, int maxtype, 1749 const struct nla_policy *policy, 1750 unsigned int validate, 1751 struct netlink_ext_ack *extack) 1752{ 1753 return __nla_validate(nla_data(start), nla_len(start), maxtype, policy, 1754 validate, extack); 1755} 1756 1757static inline int 1758nla_validate_nested_deprecated(const struct nlattr *start, int maxtype, 1759 const struct nla_policy *policy, 1760 struct netlink_ext_ack *extack) 1761{ 1762 return __nla_validate_nested(start, maxtype, policy, 1763 NL_VALIDATE_LIBERAL, extack); 1764} 1765 1766/** 1767 * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute 1768 * @skb: socket buffer the message is stored in 1769 * 1770 * Return true if padding is needed to align the next attribute (nla_data()) to 1771 * a 64-bit aligned area. 1772 */ 1773static inline bool nla_need_padding_for_64bit(struct sk_buff *skb) 1774{ 1775#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 1776 /* The nlattr header is 4 bytes in size, that's why we test 1777 * if the skb->data _is_ aligned. A NOP attribute, plus 1778 * nlattr header for next attribute, will make nla_data() 1779 * 8-byte aligned. 1780 */ 1781 if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8)) 1782 return true; 1783#endif 1784 return false; 1785} 1786 1787/** 1788 * nla_align_64bit - 64-bit align the nla_data() of next attribute 1789 * @skb: socket buffer the message is stored in 1790 * @padattr: attribute type for the padding 1791 * 1792 * Conditionally emit a padding netlink attribute in order to make 1793 * the next attribute we emit have a 64-bit aligned nla_data() area. 1794 * This will only be done in architectures which do not have 1795 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined. 1796 * 1797 * Returns zero on success or a negative error code. 1798 */ 1799static inline int nla_align_64bit(struct sk_buff *skb, int padattr) 1800{ 1801 if (nla_need_padding_for_64bit(skb) && 1802 !nla_reserve(skb, padattr, 0)) 1803 return -EMSGSIZE; 1804 1805 return 0; 1806} 1807 1808/** 1809 * nla_total_size_64bit - total length of attribute including padding 1810 * @payload: length of payload 1811 */ 1812static inline int nla_total_size_64bit(int payload) 1813{ 1814 return NLA_ALIGN(nla_attr_size(payload)) 1815#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 1816 + NLA_ALIGN(nla_attr_size(0)) 1817#endif 1818 ; 1819} 1820 1821/** 1822 * nla_for_each_attr - iterate over a stream of attributes 1823 * @pos: loop counter, set to current attribute 1824 * @head: head of attribute stream 1825 * @len: length of attribute stream 1826 * @rem: initialized to len, holds bytes currently remaining in stream 1827 */ 1828#define nla_for_each_attr(pos, head, len, rem) \ 1829 for (pos = head, rem = len; \ 1830 nla_ok(pos, rem); \ 1831 pos = nla_next(pos, &(rem))) 1832 1833/** 1834 * nla_for_each_nested - iterate over nested attributes 1835 * @pos: loop counter, set to current attribute 1836 * @nla: attribute containing the nested attributes 1837 * @rem: initialized to len, holds bytes currently remaining in stream 1838 */ 1839#define nla_for_each_nested(pos, nla, rem) \ 1840 nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) 1841 1842/** 1843 * nla_is_last - Test if attribute is last in stream 1844 * @nla: attribute to test 1845 * @rem: bytes remaining in stream 1846 */ 1847static inline bool nla_is_last(const struct nlattr *nla, int rem) 1848{ 1849 return nla->nla_len == rem; 1850} 1851 1852#endif 1853