diff options
Diffstat (limited to 'include/net/netlink.h')
| -rw-r--r-- | include/net/netlink.h | 883 |
1 files changed, 883 insertions, 0 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h new file mode 100644 index 000000000000..640c26a90cf1 --- /dev/null +++ b/include/net/netlink.h | |||
| @@ -0,0 +1,883 @@ | |||
| 1 | #ifndef __NET_NETLINK_H | ||
| 2 | #define __NET_NETLINK_H | ||
| 3 | |||
| 4 | #include <linux/types.h> | ||
| 5 | #include <linux/netlink.h> | ||
| 6 | |||
| 7 | /* ======================================================================== | ||
| 8 | * Netlink Messages and Attributes Interface (As Seen On TV) | ||
| 9 | * ------------------------------------------------------------------------ | ||
| 10 | * Messages Interface | ||
| 11 | * ------------------------------------------------------------------------ | ||
| 12 | * | ||
| 13 | * Message Format: | ||
| 14 | * <--- nlmsg_total_size(payload) ---> | ||
| 15 | * <-- nlmsg_msg_size(payload) -> | ||
| 16 | * +----------+- - -+-------------+- - -+-------- - - | ||
| 17 | * | nlmsghdr | Pad | Payload | Pad | nlmsghdr | ||
| 18 | * +----------+- - -+-------------+- - -+-------- - - | ||
| 19 | * nlmsg_data(nlh)---^ ^ | ||
| 20 | * nlmsg_next(nlh)-----------------------+ | ||
| 21 | * | ||
| 22 | * Payload Format: | ||
| 23 | * <---------------------- nlmsg_len(nlh) ---------------------> | ||
| 24 | * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) -> | ||
| 25 | * +----------------------+- - -+--------------------------------+ | ||
| 26 | * | Family Header | Pad | Attributes | | ||
| 27 | * +----------------------+- - -+--------------------------------+ | ||
| 28 | * nlmsg_attrdata(nlh, hdrlen)---^ | ||
| 29 | * | ||
| 30 | * Data Structures: | ||
| 31 | * struct nlmsghdr netlink message header | ||
| 32 | * | ||
| 33 | * Message Construction: | ||
| 34 | * nlmsg_new() create a new netlink message | ||
| 35 | * nlmsg_put() add a netlink message to an skb | ||
| 36 | * nlmsg_put_answer() callback based nlmsg_put() | ||
| 37 | * nlmsg_end() finanlize netlink message | ||
| 38 | * nlmsg_cancel() cancel message construction | ||
| 39 | * nlmsg_free() free a netlink message | ||
| 40 | * | ||
| 41 | * Message Sending: | ||
| 42 | * nlmsg_multicast() multicast message to several groups | ||
| 43 | * nlmsg_unicast() unicast a message to a single socket | ||
| 44 | * | ||
| 45 | * Message Length Calculations: | ||
| 46 | * nlmsg_msg_size(payload) length of message w/o padding | ||
| 47 | * nlmsg_total_size(payload) length of message w/ padding | ||
| 48 | * nlmsg_padlen(payload) length of padding at tail | ||
| 49 | * | ||
| 50 | * Message Payload Access: | ||
| 51 | * nlmsg_data(nlh) head of message payload | ||
| 52 | * nlmsg_len(nlh) length of message payload | ||
| 53 | * nlmsg_attrdata(nlh, hdrlen) head of attributes data | ||
| 54 | * nlmsg_attrlen(nlh, hdrlen) length of attributes data | ||
| 55 | * | ||
| 56 | * Message Parsing: | ||
| 57 | * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes? | ||
| 58 | * nlmsg_next(nlh, remaining) get next netlink message | ||
| 59 | * nlmsg_parse() parse attributes of a message | ||
| 60 | * nlmsg_find_attr() find an attribute in a message | ||
| 61 | * nlmsg_for_each_msg() loop over all messages | ||
| 62 | * nlmsg_validate() validate netlink message incl. attrs | ||
| 63 | * nlmsg_for_each_attr() loop over all attributes | ||
| 64 | * | ||
| 65 | * ------------------------------------------------------------------------ | ||
| 66 | * Attributes Interface | ||
| 67 | * ------------------------------------------------------------------------ | ||
| 68 | * | ||
| 69 | * Attribute Format: | ||
| 70 | * <------- nla_total_size(payload) -------> | ||
| 71 | * <---- nla_attr_size(payload) -----> | ||
| 72 | * +----------+- - -+- - - - - - - - - +- - -+-------- - - | ||
| 73 | * | Header | Pad | Payload | Pad | Header | ||
| 74 | * +----------+- - -+- - - - - - - - - +- - -+-------- - - | ||
| 75 | * <- nla_len(nla) -> ^ | ||
| 76 | * nla_data(nla)----^ | | ||
| 77 | * nla_next(nla)-----------------------------' | ||
| 78 | * | ||
| 79 | * Data Structures: | ||
| 80 | * struct nlattr netlink attribtue header | ||
| 81 | * | ||
| 82 | * Attribute Construction: | ||
| 83 | * nla_reserve(skb, type, len) reserve skb tailroom for an attribute | ||
| 84 | * nla_put(skb, type, len, data) add attribute to skb | ||
| 85 | * | ||
| 86 | * Attribute Construction for Basic Types: | ||
| 87 | * nla_put_u8(skb, type, value) add u8 attribute to skb | ||
| 88 | * nla_put_u16(skb, type, value) add u16 attribute to skb | ||
| 89 | * nla_put_u32(skb, type, value) add u32 attribute to skb | ||
| 90 | * nla_put_u64(skb, type, value) add u64 attribute to skb | ||
| 91 | * nla_put_string(skb, type, str) add string attribute to skb | ||
| 92 | * nla_put_flag(skb, type) add flag attribute to skb | ||
| 93 | * nla_put_msecs(skb, type, jiffies) add msecs attribute to skb | ||
| 94 | * | ||
| 95 | * Exceptions Based Attribute Construction: | ||
| 96 | * NLA_PUT(skb, type, len, data) add attribute to skb | ||
| 97 | * NLA_PUT_U8(skb, type, value) add u8 attribute to skb | ||
| 98 | * NLA_PUT_U16(skb, type, value) add u16 attribute to skb | ||
| 99 | * NLA_PUT_U32(skb, type, value) add u32 attribute to skb | ||
| 100 | * NLA_PUT_U64(skb, type, value) add u64 attribute to skb | ||
| 101 | * NLA_PUT_STRING(skb, type, str) add string attribute to skb | ||
| 102 | * NLA_PUT_FLAG(skb, type) add flag attribute to skb | ||
| 103 | * NLA_PUT_MSECS(skb, type, jiffies) add msecs attribute to skb | ||
| 104 | * | ||
| 105 | * The meaning of these functions is equal to their lower case | ||
| 106 | * variants but they jump to the label nla_put_failure in case | ||
| 107 | * of a failure. | ||
| 108 | * | ||
| 109 | * Nested Attributes Construction: | ||
| 110 | * nla_nest_start(skb, type) start a nested attribute | ||
| 111 | * nla_nest_end(skb, nla) finalize a nested attribute | ||
| 112 | * nla_nest_cancel(skb, nla) cancel nested attribute construction | ||
| 113 | * | ||
| 114 | * Attribute Length Calculations: | ||
| 115 | * nla_attr_size(payload) length of attribute w/o padding | ||
| 116 | * nla_total_size(payload) length of attribute w/ padding | ||
| 117 | * nla_padlen(payload) length of padding | ||
| 118 | * | ||
| 119 | * Attribute Payload Access: | ||
| 120 | * nla_data(nla) head of attribute payload | ||
| 121 | * nla_len(nla) length of attribute payload | ||
| 122 | * | ||
| 123 | * Attribute Payload Access for Basic Types: | ||
| 124 | * nla_get_u8(nla) get payload for a u8 attribute | ||
| 125 | * nla_get_u16(nla) get payload for a u16 attribute | ||
| 126 | * nla_get_u32(nla) get payload for a u32 attribute | ||
| 127 | * nla_get_u64(nla) get payload for a u64 attribute | ||
| 128 | * nla_get_flag(nla) return 1 if flag is true | ||
| 129 | * nla_get_msecs(nla) get payload for a msecs attribute | ||
| 130 | * | ||
| 131 | * Attribute Misc: | ||
| 132 | * nla_memcpy(dest, nla, count) copy attribute into memory | ||
| 133 | * nla_memcmp(nla, data, size) compare attribute with memory area | ||
| 134 | * nla_strlcpy(dst, nla, size) copy attribute to a sized string | ||
| 135 | * nla_strcmp(nla, str) compare attribute with string | ||
| 136 | * | ||
| 137 | * Attribute Parsing: | ||
| 138 | * nla_ok(nla, remaining) does nla fit into remaining bytes? | ||
| 139 | * nla_next(nla, remaining) get next netlink attribute | ||
| 140 | * nla_validate() validate a stream of attributes | ||
| 141 | * nla_find() find attribute in stream of attributes | ||
| 142 | * nla_parse() parse and validate stream of attrs | ||
| 143 | * nla_parse_nested() parse nested attribuets | ||
| 144 | * nla_for_each_attr() loop over all attributes | ||
| 145 | *========================================================================= | ||
| 146 | */ | ||
| 147 | |||
| 148 | /** | ||
| 149 | * Standard attribute types to specify validation policy | ||
| 150 | */ | ||
| 151 | enum { | ||
| 152 | NLA_UNSPEC, | ||
| 153 | NLA_U8, | ||
| 154 | NLA_U16, | ||
| 155 | NLA_U32, | ||
| 156 | NLA_U64, | ||
| 157 | NLA_STRING, | ||
| 158 | NLA_FLAG, | ||
| 159 | NLA_MSECS, | ||
| 160 | NLA_NESTED, | ||
| 161 | __NLA_TYPE_MAX, | ||
| 162 | }; | ||
| 163 | |||
| 164 | #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) | ||
| 165 | |||
| 166 | /** | ||
| 167 | * struct nla_policy - attribute validation policy | ||
| 168 | * @type: Type of attribute or NLA_UNSPEC | ||
| 169 | * @minlen: Minimal length of payload required to be available | ||
| 170 | * | ||
| 171 | * Policies are defined as arrays of this struct, the array must be | ||
| 172 | * accessible by attribute type up to the highest identifier to be expected. | ||
| 173 | * | ||
| 174 | * Example: | ||
| 175 | * static struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = { | ||
| 176 | * [ATTR_FOO] = { .type = NLA_U16 }, | ||
| 177 | * [ATTR_BAR] = { .type = NLA_STRING }, | ||
| 178 | * [ATTR_BAZ] = { .minlen = sizeof(struct mystruct) }, | ||
| 179 | * }; | ||
| 180 | */ | ||
| 181 | struct nla_policy { | ||
| 182 | u16 type; | ||
| 183 | u16 minlen; | ||
| 184 | }; | ||
| 185 | |||
| 186 | extern void netlink_run_queue(struct sock *sk, unsigned int *qlen, | ||
| 187 | int (*cb)(struct sk_buff *, | ||
| 188 | struct nlmsghdr *, int *)); | ||
| 189 | extern void netlink_queue_skip(struct nlmsghdr *nlh, | ||
| 190 | struct sk_buff *skb); | ||
| 191 | |||
| 192 | extern int nla_validate(struct nlattr *head, int len, int maxtype, | ||
| 193 | struct nla_policy *policy); | ||
| 194 | extern int nla_parse(struct nlattr *tb[], int maxtype, | ||
| 195 | struct nlattr *head, int len, | ||
| 196 | struct nla_policy *policy); | ||
| 197 | extern struct nlattr * nla_find(struct nlattr *head, int len, int attrtype); | ||
| 198 | extern size_t nla_strlcpy(char *dst, const struct nlattr *nla, | ||
| 199 | size_t dstsize); | ||
| 200 | extern int nla_memcpy(void *dest, struct nlattr *src, int count); | ||
| 201 | extern int nla_memcmp(const struct nlattr *nla, const void *data, | ||
| 202 | size_t size); | ||
| 203 | extern int nla_strcmp(const struct nlattr *nla, const char *str); | ||
| 204 | extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype, | ||
| 205 | int attrlen); | ||
| 206 | extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype, | ||
| 207 | int attrlen); | ||
| 208 | extern void __nla_put(struct sk_buff *skb, int attrtype, | ||
| 209 | int attrlen, const void *data); | ||
| 210 | extern int nla_put(struct sk_buff *skb, int attrtype, | ||
| 211 | int attrlen, const void *data); | ||
| 212 | |||
| 213 | /************************************************************************** | ||
| 214 | * Netlink Messages | ||
| 215 | **************************************************************************/ | ||
| 216 | |||
| 217 | /** | ||
| 218 | * nlmsg_msg_size - length of netlink message not including padding | ||
| 219 | * @payload: length of message payload | ||
| 220 | */ | ||
| 221 | static inline int nlmsg_msg_size(int payload) | ||
| 222 | { | ||
| 223 | return NLMSG_HDRLEN + payload; | ||
| 224 | } | ||
| 225 | |||
| 226 | /** | ||
| 227 | * nlmsg_total_size - length of netlink message including padding | ||
| 228 | * @payload: length of message payload | ||
| 229 | */ | ||
| 230 | static inline int nlmsg_total_size(int payload) | ||
| 231 | { | ||
| 232 | return NLMSG_ALIGN(nlmsg_msg_size(payload)); | ||
| 233 | } | ||
| 234 | |||
| 235 | /** | ||
| 236 | * nlmsg_padlen - length of padding at the message's tail | ||
| 237 | * @payload: length of message payload | ||
| 238 | */ | ||
| 239 | static inline int nlmsg_padlen(int payload) | ||
| 240 | { | ||
| 241 | return nlmsg_total_size(payload) - nlmsg_msg_size(payload); | ||
| 242 | } | ||
| 243 | |||
| 244 | /** | ||
| 245 | * nlmsg_data - head of message payload | ||
| 246 | * @nlh: netlink messsage header | ||
| 247 | */ | ||
| 248 | static inline void *nlmsg_data(const struct nlmsghdr *nlh) | ||
| 249 | { | ||
| 250 | return (unsigned char *) nlh + NLMSG_HDRLEN; | ||
| 251 | } | ||
| 252 | |||
| 253 | /** | ||
| 254 | * nlmsg_len - length of message payload | ||
| 255 | * @nlh: netlink message header | ||
| 256 | */ | ||
| 257 | static inline int nlmsg_len(const struct nlmsghdr *nlh) | ||
| 258 | { | ||
| 259 | return nlh->nlmsg_len - NLMSG_HDRLEN; | ||
| 260 | } | ||
| 261 | |||
| 262 | /** | ||
| 263 | * nlmsg_attrdata - head of attributes data | ||
| 264 | * @nlh: netlink message header | ||
| 265 | * @hdrlen: length of family specific header | ||
| 266 | */ | ||
| 267 | static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, | ||
| 268 | int hdrlen) | ||
| 269 | { | ||
| 270 | unsigned char *data = nlmsg_data(nlh); | ||
| 271 | return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); | ||
| 272 | } | ||
| 273 | |||
| 274 | /** | ||
| 275 | * nlmsg_attrlen - length of attributes data | ||
| 276 | * @nlh: netlink message header | ||
| 277 | * @hdrlen: length of family specific header | ||
| 278 | */ | ||
| 279 | static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) | ||
| 280 | { | ||
| 281 | return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); | ||
| 282 | } | ||
| 283 | |||
| 284 | /** | ||
| 285 | * nlmsg_ok - check if the netlink message fits into the remaining bytes | ||
| 286 | * @nlh: netlink message header | ||
| 287 | * @remaining: number of bytes remaining in message stream | ||
| 288 | */ | ||
| 289 | static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) | ||
| 290 | { | ||
| 291 | return (remaining >= sizeof(struct nlmsghdr) && | ||
| 292 | nlh->nlmsg_len >= sizeof(struct nlmsghdr) && | ||
| 293 | nlh->nlmsg_len <= remaining); | ||
| 294 | } | ||
| 295 | |||
| 296 | /** | ||
| 297 | * nlmsg_next - next netlink message in message stream | ||
| 298 | * @nlh: netlink message header | ||
| 299 | * @remaining: number of bytes remaining in message stream | ||
| 300 | * | ||
| 301 | * Returns the next netlink message in the message stream and | ||
| 302 | * decrements remaining by the size of the current message. | ||
| 303 | */ | ||
| 304 | static inline struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining) | ||
| 305 | { | ||
| 306 | int totlen = NLMSG_ALIGN(nlh->nlmsg_len); | ||
| 307 | |||
| 308 | *remaining -= totlen; | ||
| 309 | |||
| 310 | return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); | ||
| 311 | } | ||
| 312 | |||
| 313 | /** | ||
| 314 | * nlmsg_parse - parse attributes of a netlink message | ||
| 315 | * @nlh: netlink message header | ||
| 316 | * @hdrlen: length of family specific header | ||
| 317 | * @tb: destination array with maxtype+1 elements | ||
| 318 | * @maxtype: maximum attribute type to be expected | ||
| 319 | * @policy: validation policy | ||
| 320 | * | ||
| 321 | * See nla_parse() | ||
| 322 | */ | ||
| 323 | static inline int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen, | ||
| 324 | struct nlattr *tb[], int maxtype, | ||
| 325 | struct nla_policy *policy) | ||
| 326 | { | ||
| 327 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | ||
| 328 | return -EINVAL; | ||
| 329 | |||
| 330 | return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), | ||
| 331 | nlmsg_attrlen(nlh, hdrlen), policy); | ||
| 332 | } | ||
| 333 | |||
| 334 | /** | ||
| 335 | * nlmsg_find_attr - find a specific attribute in a netlink message | ||
| 336 | * @nlh: netlink message header | ||
| 337 | * @hdrlen: length of familiy specific header | ||
| 338 | * @attrtype: type of attribute to look for | ||
| 339 | * | ||
| 340 | * Returns the first attribute which matches the specified type. | ||
| 341 | */ | ||
| 342 | static inline struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh, | ||
| 343 | int hdrlen, int attrtype) | ||
| 344 | { | ||
| 345 | return nla_find(nlmsg_attrdata(nlh, hdrlen), | ||
| 346 | nlmsg_attrlen(nlh, hdrlen), attrtype); | ||
| 347 | } | ||
| 348 | |||
| 349 | /** | ||
| 350 | * nlmsg_validate - validate a netlink message including attributes | ||
| 351 | * @nlh: netlinket message header | ||
| 352 | * @hdrlen: length of familiy specific header | ||
| 353 | * @maxtype: maximum attribute type to be expected | ||
| 354 | * @policy: validation policy | ||
| 355 | */ | ||
| 356 | static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype, | ||
| 357 | struct nla_policy *policy) | ||
| 358 | { | ||
| 359 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | ||
| 360 | return -EINVAL; | ||
| 361 | |||
| 362 | return nla_validate(nlmsg_attrdata(nlh, hdrlen), | ||
| 363 | nlmsg_attrlen(nlh, hdrlen), maxtype, policy); | ||
| 364 | } | ||
| 365 | |||
| 366 | /** | ||
| 367 | * nlmsg_for_each_attr - iterate over a stream of attributes | ||
| 368 | * @pos: loop counter, set to current attribute | ||
| 369 | * @nlh: netlink message header | ||
| 370 | * @hdrlen: length of familiy specific header | ||
| 371 | * @rem: initialized to len, holds bytes currently remaining in stream | ||
| 372 | */ | ||
| 373 | #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ | ||
| 374 | nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ | ||
| 375 | nlmsg_attrlen(nlh, hdrlen), rem) | ||
| 376 | |||
| 377 | #if 0 | ||
| 378 | /* FIXME: Enable once all users have been converted */ | ||
| 379 | |||
| 380 | /** | ||
| 381 | * __nlmsg_put - Add a new netlink message to an skb | ||
| 382 | * @skb: socket buffer to store message in | ||
| 383 | * @pid: netlink process id | ||
| 384 | * @seq: sequence number of message | ||
| 385 | * @type: message type | ||
| 386 | * @payload: length of message payload | ||
| 387 | * @flags: message flags | ||
| 388 | * | ||
| 389 | * The caller is responsible to ensure that the skb provides enough | ||
| 390 | * tailroom for both the netlink header and payload. | ||
| 391 | */ | ||
| 392 | static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid, | ||
| 393 | u32 seq, int type, int payload, | ||
| 394 | int flags) | ||
| 395 | { | ||
| 396 | struct nlmsghdr *nlh; | ||
| 397 | |||
| 398 | nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload)); | ||
| 399 | nlh->nlmsg_type = type; | ||
| 400 | nlh->nlmsg_len = nlmsg_msg_size(payload); | ||
| 401 | nlh->nlmsg_flags = flags; | ||
| 402 | nlh->nlmsg_pid = pid; | ||
| 403 | nlh->nlmsg_seq = seq; | ||
| 404 | |||
| 405 | memset((unsigned char *) nlmsg_data(nlh) + payload, 0, | ||
| 406 | nlmsg_padlen(payload)); | ||
| 407 | |||
| 408 | return nlh; | ||
| 409 | } | ||
| 410 | #endif | ||
| 411 | |||
| 412 | /** | ||
| 413 | * nlmsg_put - Add a new netlink message to an skb | ||
| 414 | * @skb: socket buffer to store message in | ||
| 415 | * @pid: netlink process id | ||
| 416 | * @seq: sequence number of message | ||
| 417 | * @type: message type | ||
| 418 | * @payload: length of message payload | ||
| 419 | * @flags: message flags | ||
| 420 | * | ||
| 421 | * Returns NULL if the tailroom of the skb is insufficient to store | ||
| 422 | * the message header and payload. | ||
| 423 | */ | ||
| 424 | static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, | ||
| 425 | int type, int payload, int flags) | ||
| 426 | { | ||
| 427 | if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) | ||
| 428 | return NULL; | ||
| 429 | |||
| 430 | return __nlmsg_put(skb, pid, seq, type, payload, flags); | ||
| 431 | } | ||
| 432 | |||
| 433 | /** | ||
| 434 | * nlmsg_put_answer - Add a new callback based netlink message to an skb | ||
| 435 | * @skb: socket buffer to store message in | ||
| 436 | * @cb: netlink callback | ||
| 437 | * @type: message type | ||
| 438 | * @payload: length of message payload | ||
| 439 | * @flags: message flags | ||
| 440 | * | ||
| 441 | * Returns NULL if the tailroom of the skb is insufficient to store | ||
| 442 | * the message header and payload. | ||
| 443 | */ | ||
| 444 | static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, | ||
| 445 | struct netlink_callback *cb, | ||
| 446 | int type, int payload, | ||
| 447 | int flags) | ||
| 448 | { | ||
| 449 | return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, | ||
| 450 | type, payload, flags); | ||
| 451 | } | ||
| 452 | |||
| 453 | /** | ||
| 454 | * nlmsg_new - Allocate a new netlink message | ||
| 455 | * @size: maximum size of message | ||
| 456 | * | ||
| 457 | * Use NLMSG_GOODSIZE if size isn't know and you need a good default size. | ||
| 458 | */ | ||
| 459 | static inline struct sk_buff *nlmsg_new(int size) | ||
| 460 | { | ||
| 461 | return alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); | ||
| 462 | } | ||
| 463 | |||
| 464 | /** | ||
| 465 | * nlmsg_end - Finalize a netlink message | ||
| 466 | * @skb: socket buffer the message is stored in | ||
| 467 | * @nlh: netlink message header | ||
| 468 | * | ||
| 469 | * Corrects the netlink message header to include the appeneded | ||
| 470 | * attributes. Only necessary if attributes have been added to | ||
| 471 | * the message. | ||
| 472 | * | ||
| 473 | * Returns the total data length of the skb. | ||
| 474 | */ | ||
| 475 | static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) | ||
| 476 | { | ||
| 477 | nlh->nlmsg_len = skb->tail - (unsigned char *) nlh; | ||
| 478 | |||
| 479 | return skb->len; | ||
| 480 | } | ||
| 481 | |||
| 482 | /** | ||
| 483 | * nlmsg_cancel - Cancel construction of a netlink message | ||
| 484 | * @skb: socket buffer the message is stored in | ||
| 485 | * @nlh: netlink message header | ||
| 486 | * | ||
| 487 | * Removes the complete netlink message including all | ||
| 488 | * attributes from the socket buffer again. Returns -1. | ||
| 489 | */ | ||
| 490 | static inline int nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) | ||
| 491 | { | ||
| 492 | skb_trim(skb, (unsigned char *) nlh - skb->data); | ||
| 493 | |||
| 494 | return -1; | ||
| 495 | } | ||
| 496 | |||
| 497 | /** | ||
| 498 | * nlmsg_free - free a netlink message | ||
| 499 | * @skb: socket buffer of netlink message | ||
| 500 | */ | ||
| 501 | static inline void nlmsg_free(struct sk_buff *skb) | ||
| 502 | { | ||
| 503 | kfree_skb(skb); | ||
| 504 | } | ||
| 505 | |||
| 506 | /** | ||
| 507 | * nlmsg_multicast - multicast a netlink message | ||
| 508 | * @sk: netlink socket to spread messages to | ||
| 509 | * @skb: netlink message as socket buffer | ||
| 510 | * @pid: own netlink pid to avoid sending to yourself | ||
| 511 | * @group: multicast group id | ||
| 512 | */ | ||
| 513 | static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, | ||
| 514 | u32 pid, unsigned int group) | ||
| 515 | { | ||
| 516 | int err; | ||
| 517 | |||
| 518 | NETLINK_CB(skb).dst_group = group; | ||
| 519 | |||
| 520 | err = netlink_broadcast(sk, skb, pid, group, GFP_KERNEL); | ||
| 521 | if (err > 0) | ||
| 522 | err = 0; | ||
| 523 | |||
| 524 | return err; | ||
| 525 | } | ||
| 526 | |||
| 527 | /** | ||
| 528 | * nlmsg_unicast - unicast a netlink message | ||
| 529 | * @sk: netlink socket to spread message to | ||
| 530 | * @skb: netlink message as socket buffer | ||
| 531 | * @pid: netlink pid of the destination socket | ||
| 532 | */ | ||
| 533 | static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid) | ||
| 534 | { | ||
| 535 | int err; | ||
| 536 | |||
| 537 | err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT); | ||
| 538 | if (err > 0) | ||
| 539 | err = 0; | ||
| 540 | |||
| 541 | return err; | ||
| 542 | } | ||
| 543 | |||
| 544 | /** | ||
| 545 | * nlmsg_for_each_msg - iterate over a stream of messages | ||
| 546 | * @pos: loop counter, set to current message | ||
| 547 | * @head: head of message stream | ||
| 548 | * @len: length of message stream | ||
| 549 | * @rem: initialized to len, holds bytes currently remaining in stream | ||
| 550 | */ | ||
| 551 | #define nlmsg_for_each_msg(pos, head, len, rem) \ | ||
| 552 | for (pos = head, rem = len; \ | ||
| 553 | nlmsg_ok(pos, rem); \ | ||
| 554 | pos = nlmsg_next(pos, &(rem))) | ||
| 555 | |||
| 556 | /************************************************************************** | ||
| 557 | * Netlink Attributes | ||
| 558 | **************************************************************************/ | ||
| 559 | |||
| 560 | /** | ||
| 561 | * nla_attr_size - length of attribute not including padding | ||
| 562 | * @payload: length of payload | ||
| 563 | */ | ||
| 564 | static inline int nla_attr_size(int payload) | ||
| 565 | { | ||
| 566 | return NLA_HDRLEN + payload; | ||
| 567 | } | ||
| 568 | |||
| 569 | /** | ||
| 570 | * nla_total_size - total length of attribute including padding | ||
| 571 | * @payload: length of payload | ||
| 572 | */ | ||
| 573 | static inline int nla_total_size(int payload) | ||
| 574 | { | ||
| 575 | return NLA_ALIGN(nla_attr_size(payload)); | ||
| 576 | } | ||
| 577 | |||
| 578 | /** | ||
| 579 | * nla_padlen - length of padding at the tail of attribute | ||
| 580 | * @payload: length of payload | ||
| 581 | */ | ||
| 582 | static inline int nla_padlen(int payload) | ||
| 583 | { | ||
| 584 | return nla_total_size(payload) - nla_attr_size(payload); | ||
| 585 | } | ||
| 586 | |||
| 587 | /** | ||
| 588 | * nla_data - head of payload | ||
| 589 | * @nla: netlink attribute | ||
| 590 | */ | ||
| 591 | static inline void *nla_data(const struct nlattr *nla) | ||
| 592 | { | ||
| 593 | return (char *) nla + NLA_HDRLEN; | ||
| 594 | } | ||
| 595 | |||
| 596 | /** | ||
| 597 | * nla_len - length of payload | ||
| 598 | * @nla: netlink attribute | ||
| 599 | */ | ||
| 600 | static inline int nla_len(const struct nlattr *nla) | ||
| 601 | { | ||
| 602 | return nla->nla_len - NLA_HDRLEN; | ||
| 603 | } | ||
| 604 | |||
| 605 | /** | ||
| 606 | * nla_ok - check if the netlink attribute fits into the remaining bytes | ||
| 607 | * @nla: netlink attribute | ||
| 608 | * @remaining: number of bytes remaining in attribute stream | ||
| 609 | */ | ||
| 610 | static inline int nla_ok(const struct nlattr *nla, int remaining) | ||
| 611 | { | ||
| 612 | return remaining >= sizeof(*nla) && | ||
| 613 | nla->nla_len >= sizeof(*nla) && | ||
| 614 | nla->nla_len <= remaining; | ||
| 615 | } | ||
| 616 | |||
| 617 | /** | ||
| 618 | * nla_next - next netlink attribte in attribute stream | ||
| 619 | * @nla: netlink attribute | ||
| 620 | * @remaining: number of bytes remaining in attribute stream | ||
| 621 | * | ||
| 622 | * Returns the next netlink attribute in the attribute stream and | ||
| 623 | * decrements remaining by the size of the current attribute. | ||
| 624 | */ | ||
| 625 | static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) | ||
| 626 | { | ||
| 627 | int totlen = NLA_ALIGN(nla->nla_len); | ||
| 628 | |||
| 629 | *remaining -= totlen; | ||
| 630 | return (struct nlattr *) ((char *) nla + totlen); | ||
| 631 | } | ||
| 632 | |||
| 633 | /** | ||
| 634 | * nla_parse_nested - parse nested attributes | ||
| 635 | * @tb: destination array with maxtype+1 elements | ||
| 636 | * @maxtype: maximum attribute type to be expected | ||
| 637 | * @nla: attribute containing the nested attributes | ||
| 638 | * @policy: validation policy | ||
| 639 | * | ||
| 640 | * See nla_parse() | ||
| 641 | */ | ||
| 642 | static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, | ||
| 643 | struct nlattr *nla, | ||
| 644 | struct nla_policy *policy) | ||
| 645 | { | ||
| 646 | return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); | ||
| 647 | } | ||
| 648 | /** | ||
| 649 | * nla_put_u8 - Add a u16 netlink attribute to a socket buffer | ||
| 650 | * @skb: socket buffer to add attribute to | ||
| 651 | * @attrtype: attribute type | ||
| 652 | * @value: numeric value | ||
| 653 | */ | ||
| 654 | static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) | ||
| 655 | { | ||
| 656 | return nla_put(skb, attrtype, sizeof(u8), &value); | ||
| 657 | } | ||
| 658 | |||
| 659 | /** | ||
| 660 | * nla_put_u16 - Add a u16 netlink attribute to a socket buffer | ||
| 661 | * @skb: socket buffer to add attribute to | ||
| 662 | * @attrtype: attribute type | ||
| 663 | * @value: numeric value | ||
| 664 | */ | ||
| 665 | static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) | ||
| 666 | { | ||
| 667 | return nla_put(skb, attrtype, sizeof(u16), &value); | ||
| 668 | } | ||
| 669 | |||
| 670 | /** | ||
| 671 | * nla_put_u32 - Add a u32 netlink attribute to a socket buffer | ||
| 672 | * @skb: socket buffer to add attribute to | ||
| 673 | * @attrtype: attribute type | ||
| 674 | * @value: numeric value | ||
| 675 | */ | ||
| 676 | static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) | ||
| 677 | { | ||
| 678 | return nla_put(skb, attrtype, sizeof(u32), &value); | ||
| 679 | } | ||
| 680 | |||
| 681 | /** | ||
| 682 | * nla_put_64 - Add a u64 netlink attribute to a socket buffer | ||
| 683 | * @skb: socket buffer to add attribute to | ||
| 684 | * @attrtype: attribute type | ||
| 685 | * @value: numeric value | ||
| 686 | */ | ||
| 687 | static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value) | ||
| 688 | { | ||
| 689 | return nla_put(skb, attrtype, sizeof(u64), &value); | ||
| 690 | } | ||
| 691 | |||
| 692 | /** | ||
| 693 | * nla_put_string - Add a string netlink attribute to a socket buffer | ||
| 694 | * @skb: socket buffer to add attribute to | ||
| 695 | * @attrtype: attribute type | ||
| 696 | * @str: NUL terminated string | ||
| 697 | */ | ||
| 698 | static inline int nla_put_string(struct sk_buff *skb, int attrtype, | ||
| 699 | const char *str) | ||
| 700 | { | ||
| 701 | return nla_put(skb, attrtype, strlen(str) + 1, str); | ||
| 702 | } | ||
| 703 | |||
| 704 | /** | ||
| 705 | * nla_put_flag - Add a flag netlink attribute to a socket buffer | ||
| 706 | * @skb: socket buffer to add attribute to | ||
| 707 | * @attrtype: attribute type | ||
| 708 | */ | ||
| 709 | static inline int nla_put_flag(struct sk_buff *skb, int attrtype) | ||
| 710 | { | ||
| 711 | return nla_put(skb, attrtype, 0, NULL); | ||
| 712 | } | ||
| 713 | |||
| 714 | /** | ||
| 715 | * nla_put_msecs - Add a msecs netlink attribute to a socket buffer | ||
| 716 | * @skb: socket buffer to add attribute to | ||
| 717 | * @attrtype: attribute type | ||
| 718 | * @jiffies: number of msecs in jiffies | ||
| 719 | */ | ||
| 720 | static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, | ||
| 721 | unsigned long jiffies) | ||
| 722 | { | ||
| 723 | u64 tmp = jiffies_to_msecs(jiffies); | ||
| 724 | return nla_put(skb, attrtype, sizeof(u64), &tmp); | ||
| 725 | } | ||
| 726 | |||
| 727 | #define NLA_PUT(skb, attrtype, attrlen, data) \ | ||
| 728 | do { \ | ||
| 729 | if (nla_put(skb, attrtype, attrlen, data) < 0) \ | ||
| 730 | goto nla_put_failure; \ | ||
| 731 | } while(0) | ||
| 732 | |||
| 733 | #define NLA_PUT_TYPE(skb, type, attrtype, value) \ | ||
| 734 | do { \ | ||
| 735 | type __tmp = value; \ | ||
| 736 | NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \ | ||
| 737 | } while(0) | ||
| 738 | |||
| 739 | #define NLA_PUT_U8(skb, attrtype, value) \ | ||
| 740 | NLA_PUT_TYPE(skb, u8, attrtype, value) | ||
| 741 | |||
| 742 | #define NLA_PUT_U16(skb, attrtype, value) \ | ||
| 743 | NLA_PUT_TYPE(skb, u16, attrtype, value) | ||
| 744 | |||
| 745 | #define NLA_PUT_U32(skb, attrtype, value) \ | ||
| 746 | NLA_PUT_TYPE(skb, u32, attrtype, value) | ||
| 747 | |||
| 748 | #define NLA_PUT_U64(skb, attrtype, value) \ | ||
| 749 | NLA_PUT_TYPE(skb, u64, attrtype, value) | ||
| 750 | |||
| 751 | #define NLA_PUT_STRING(skb, attrtype, value) \ | ||
| 752 | NLA_PUT(skb, attrtype, strlen(value) + 1, value) | ||
| 753 | |||
| 754 | #define NLA_PUT_FLAG(skb, attrtype, value) \ | ||
| 755 | NLA_PUT(skb, attrtype, 0, NULL) | ||
| 756 | |||
| 757 | #define NLA_PUT_MSECS(skb, attrtype, jiffies) \ | ||
| 758 | NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies)) | ||
| 759 | |||
| 760 | /** | ||
| 761 | * nla_get_u32 - return payload of u32 attribute | ||
| 762 | * @nla: u32 netlink attribute | ||
| 763 | */ | ||
| 764 | static inline u32 nla_get_u32(struct nlattr *nla) | ||
| 765 | { | ||
| 766 | return *(u32 *) nla_data(nla); | ||
| 767 | } | ||
| 768 | |||
| 769 | /** | ||
| 770 | * nla_get_u16 - return payload of u16 attribute | ||
| 771 | * @nla: u16 netlink attribute | ||
| 772 | */ | ||
| 773 | static inline u16 nla_get_u16(struct nlattr *nla) | ||
| 774 | { | ||
| 775 | return *(u16 *) nla_data(nla); | ||
| 776 | } | ||
| 777 | |||
| 778 | /** | ||
| 779 | * nla_get_u8 - return payload of u8 attribute | ||
| 780 | * @nla: u8 netlink attribute | ||
| 781 | */ | ||
| 782 | static inline u8 nla_get_u8(struct nlattr *nla) | ||
| 783 | { | ||
| 784 | return *(u8 *) nla_data(nla); | ||
| 785 | } | ||
| 786 | |||
| 787 | /** | ||
| 788 | * nla_get_u64 - return payload of u64 attribute | ||
| 789 | * @nla: u64 netlink attribute | ||
| 790 | */ | ||
| 791 | static inline u64 nla_get_u64(struct nlattr *nla) | ||
| 792 | { | ||
| 793 | u64 tmp; | ||
| 794 | |||
| 795 | nla_memcpy(&tmp, nla, sizeof(tmp)); | ||
| 796 | |||
| 797 | return tmp; | ||
| 798 | } | ||
| 799 | |||
| 800 | /** | ||
| 801 | * nla_get_flag - return payload of flag attribute | ||
| 802 | * @nla: flag netlink attribute | ||
| 803 | */ | ||
| 804 | static inline int nla_get_flag(struct nlattr *nla) | ||
| 805 | { | ||
| 806 | return !!nla; | ||
| 807 | } | ||
| 808 | |||
| 809 | /** | ||
| 810 | * nla_get_msecs - return payload of msecs attribute | ||
| 811 | * @nla: msecs netlink attribute | ||
| 812 | * | ||
| 813 | * Returns the number of milliseconds in jiffies. | ||
| 814 | */ | ||
| 815 | static inline unsigned long nla_get_msecs(struct nlattr *nla) | ||
| 816 | { | ||
| 817 | u64 msecs = nla_get_u64(nla); | ||
| 818 | |||
| 819 | return msecs_to_jiffies((unsigned long) msecs); | ||
| 820 | } | ||
| 821 | |||
| 822 | /** | ||
| 823 | * nla_nest_start - Start a new level of nested attributes | ||
| 824 | * @skb: socket buffer to add attributes to | ||
| 825 | * @attrtype: attribute type of container | ||
| 826 | * | ||
| 827 | * Returns the container attribute | ||
| 828 | */ | ||
| 829 | static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) | ||
| 830 | { | ||
| 831 | struct nlattr *start = (struct nlattr *) skb->tail; | ||
| 832 | |||
| 833 | if (nla_put(skb, attrtype, 0, NULL) < 0) | ||
| 834 | return NULL; | ||
| 835 | |||
| 836 | return start; | ||
| 837 | } | ||
| 838 | |||
| 839 | /** | ||
| 840 | * nla_nest_end - Finalize nesting of attributes | ||
| 841 | * @skb: socket buffer the attribtues are stored in | ||
| 842 | * @start: container attribute | ||
| 843 | * | ||
| 844 | * Corrects the container attribute header to include the all | ||
| 845 | * appeneded attributes. | ||
| 846 | * | ||
| 847 | * Returns the total data length of the skb. | ||
| 848 | */ | ||
| 849 | static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) | ||
| 850 | { | ||
| 851 | start->nla_len = skb->tail - (unsigned char *) start; | ||
| 852 | return skb->len; | ||
| 853 | } | ||
| 854 | |||
| 855 | /** | ||
| 856 | * nla_nest_cancel - Cancel nesting of attributes | ||
| 857 | * @skb: socket buffer the message is stored in | ||
| 858 | * @start: container attribute | ||
| 859 | * | ||
| 860 | * Removes the container attribute and including all nested | ||
| 861 | * attributes. Returns -1. | ||
| 862 | */ | ||
| 863 | static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) | ||
| 864 | { | ||
| 865 | if (start) | ||
| 866 | skb_trim(skb, (unsigned char *) start - skb->data); | ||
| 867 | |||
| 868 | return -1; | ||
| 869 | } | ||
| 870 | |||
| 871 | /** | ||
| 872 | * nla_for_each_attr - iterate over a stream of attributes | ||
| 873 | * @pos: loop counter, set to current attribute | ||
| 874 | * @head: head of attribute stream | ||
| 875 | * @len: length of attribute stream | ||
| 876 | * @rem: initialized to len, holds bytes currently remaining in stream | ||
| 877 | */ | ||
| 878 | #define nla_for_each_attr(pos, head, len, rem) \ | ||
| 879 | for (pos = head, rem = len; \ | ||
| 880 | nla_ok(pos, rem); \ | ||
| 881 | pos = nla_next(pos, &(rem))) | ||
| 882 | |||
| 883 | #endif | ||
