1 /* SPDX-License-Identifier: LGPL-2.1-only */ 2 /* 3 * Copyright (c) 2003-2013 Thomas Graf <tgraf@suug.ch> 4 */ 5 6 #ifndef NETLINK_ATTR_H_ 7 #define NETLINK_ATTR_H_ 8 9 #include <netlink/netlink.h> 10 #include <netlink/object.h> 11 #include <netlink/addr.h> 12 #include <netlink/data.h> 13 14 #ifdef __cplusplus 15 extern "C" { 16 #endif 17 18 struct nlattr; 19 20 struct nl_msg; 21 22 /** 23 * @name Basic Attribute Data Types 24 * @{ 25 */ 26 27 /** 28 * @ingroup attr 29 * Basic attribute data types 30 * 31 * See section @core_doc{core_attr_parse,Attribute Parsing} for more details. 32 */ 33 enum { 34 NLA_UNSPEC, /**< Unspecified type, binary data chunk */ 35 NLA_U8, /**< 8 bit integer */ 36 NLA_U16, /**< 16 bit integer */ 37 NLA_U32, /**< 32 bit integer */ 38 NLA_U64, /**< 64 bit integer */ 39 NLA_STRING, /**< NUL terminated character string */ 40 NLA_FLAG, /**< Flag */ 41 NLA_MSECS, /**< Micro seconds (64bit) */ 42 NLA_NESTED, /**< Nested attributes */ 43 NLA_NESTED_COMPAT, 44 NLA_NUL_STRING, 45 NLA_BINARY, 46 NLA_S8, 47 NLA_S16, 48 NLA_S32, 49 NLA_S64, 50 __NLA_TYPE_MAX, 51 }; 52 53 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) 54 55 /** @} */ 56 57 /** 58 * @ingroup attr 59 * Attribute validation policy. 60 * 61 * See section @core_doc{core_attr_parse,Attribute Parsing} for more details. 62 */ 63 struct nla_policy { 64 /** Type of attribute or NLA_UNSPEC */ 65 uint16_t type; 66 67 /** Minimal length of payload required */ 68 uint16_t minlen; 69 70 /** Maximal length of payload allowed */ 71 uint16_t maxlen; 72 }; 73 74 /* Size calculations */ 75 extern int nla_attr_size(int payload); 76 extern int nla_total_size(int payload); 77 extern int nla_padlen(int payload); 78 79 /* Attribute parsing */ 80 extern int nla_type(const struct nlattr *); 81 extern void * nla_data(const struct nlattr *); 82 extern int nla_len(const struct nlattr *); 83 extern int nla_ok(const struct nlattr *, int); 84 extern struct nlattr * nla_next(const struct nlattr *, int *); 85 extern int nla_parse(struct nlattr **, int, struct nlattr *, 86 int, const struct nla_policy *); 87 extern int nla_validate(const struct nlattr *, int, int, 88 const struct nla_policy *); 89 extern struct nlattr * nla_find(const struct nlattr *, int, int); 90 91 /* Helper Functions */ 92 extern int nla_memcpy(void *, const struct nlattr *, int); 93 extern size_t nla_strlcpy(char *, const struct nlattr *, size_t); 94 extern int nla_memcmp(const struct nlattr *, const void *, size_t); 95 extern int nla_strcmp(const struct nlattr *, const char *); 96 97 /* Unspecific attribute */ 98 extern struct nlattr * nla_reserve(struct nl_msg *, int, int); 99 extern int nla_put(struct nl_msg *, int, int, const void *); 100 extern int nla_put_data(struct nl_msg *, int, 101 const struct nl_data *); 102 extern int nla_put_addr(struct nl_msg *, int, struct nl_addr *); 103 104 /* Integer attribute */ 105 extern int8_t nla_get_s8(const struct nlattr *); 106 extern int nla_put_s8(struct nl_msg *, int, int8_t); 107 extern uint8_t nla_get_u8(const struct nlattr *); 108 extern int nla_put_u8(struct nl_msg *, int, uint8_t); 109 extern int16_t nla_get_s16(const struct nlattr *); 110 extern int nla_put_s16(struct nl_msg *, int, int16_t); 111 extern uint16_t nla_get_u16(const struct nlattr *); 112 extern int nla_put_u16(struct nl_msg *, int, uint16_t); 113 extern int32_t nla_get_s32(const struct nlattr *); 114 extern int nla_put_s32(struct nl_msg *, int, int32_t); 115 extern uint32_t nla_get_u32(const struct nlattr *); 116 extern int nla_put_u32(struct nl_msg *, int, uint32_t); 117 extern int64_t nla_get_s64(const struct nlattr *); 118 extern int nla_put_s64(struct nl_msg *, int, int64_t); 119 extern uint64_t nla_get_u64(const struct nlattr *); 120 extern int nla_put_u64(struct nl_msg *, int, uint64_t); 121 122 /* String attribute */ 123 extern char * nla_get_string(const struct nlattr *); 124 extern char * nla_strdup(const struct nlattr *); 125 extern int nla_put_string(struct nl_msg *, int, const char *); 126 127 /* Flag attribute */ 128 extern int nla_get_flag(const struct nlattr *); 129 extern int nla_put_flag(struct nl_msg *, int); 130 131 /* Msec attribute */ 132 extern unsigned long nla_get_msecs(const struct nlattr *); 133 extern int nla_put_msecs(struct nl_msg *, int, unsigned long); 134 135 /* Attribute nesting */ 136 extern int nla_put_nested(struct nl_msg *, int, 137 const struct nl_msg *); 138 extern struct nlattr * nla_nest_start(struct nl_msg *, int); 139 extern int nla_nest_end(struct nl_msg *, struct nlattr *); 140 extern int nla_nest_end_keep_empty(struct nl_msg *, struct nlattr *); 141 extern void nla_nest_cancel(struct nl_msg *, const struct nlattr *); 142 extern int nla_parse_nested(struct nlattr **, int, struct nlattr *, 143 const struct nla_policy *); 144 extern int nla_is_nested(const struct nlattr *); 145 146 /** 147 * @name Attribute Construction (Exception Based) 148 * @{ 149 */ 150 151 /** 152 * @ingroup attr 153 * Add unspecific attribute to netlink message. 154 * @arg msg Netlink message. 155 * @arg attrtype Attribute type. 156 * @arg attrlen Length of attribute payload. 157 * @arg data Head of attribute payload. 158 */ 159 #define NLA_PUT(msg, attrtype, attrlen, data) \ 160 do { \ 161 if (nla_put(msg, attrtype, attrlen, data) < 0) \ 162 goto nla_put_failure; \ 163 } while(0) 164 165 /** 166 * @ingroup attr 167 * Add atomic type attribute to netlink message. 168 * @arg msg Netlink message. 169 * @arg type Atomic type. 170 * @arg attrtype Attribute type. 171 * @arg value Head of attribute payload. 172 */ 173 #define NLA_PUT_TYPE(msg, type, attrtype, value) \ 174 do { \ 175 type __tmp = value; \ 176 NLA_PUT(msg, attrtype, sizeof(type), &__tmp); \ 177 } while(0) 178 179 /** 180 * Add 8 bit signed integer attribute to netlink message. 181 * @arg msg Netlink message. 182 * @arg attrtype Attribute type. 183 * @arg value Numeric value. 184 */ 185 #define NLA_PUT_S8(msg, attrtype, value) \ 186 NLA_PUT_TYPE(msg, int8_t, attrtype, value) 187 188 /** 189 * Add 8 bit integer attribute to netlink message. 190 * @arg msg Netlink message. 191 * @arg attrtype Attribute type. 192 * @arg value Numeric value. 193 */ 194 #define NLA_PUT_U8(msg, attrtype, value) \ 195 NLA_PUT_TYPE(msg, uint8_t, attrtype, value) 196 197 /** 198 * Add 16 bit signed integer attribute to netlink message. 199 * @arg msg Netlink message. 200 * @arg attrtype Attribute type. 201 * @arg value Numeric value. 202 */ 203 #define NLA_PUT_S16(msg, attrtype, value) \ 204 NLA_PUT_TYPE(msg, int16_t, attrtype, value) 205 206 /** 207 * Add 16 bit integer attribute to netlink message. 208 * @arg msg Netlink message. 209 * @arg attrtype Attribute type. 210 * @arg value Numeric value. 211 */ 212 #define NLA_PUT_U16(msg, attrtype, value) \ 213 NLA_PUT_TYPE(msg, uint16_t, attrtype, value) 214 215 /** 216 * Add 32 bit signed integer attribute to netlink message. 217 * @arg msg Netlink message. 218 * @arg attrtype Attribute type. 219 * @arg value Numeric value. 220 */ 221 #define NLA_PUT_S32(msg, attrtype, value) \ 222 NLA_PUT_TYPE(msg, int32_t, attrtype, value) 223 224 /** 225 * Add 32 bit integer attribute to netlink message. 226 * @arg msg Netlink message. 227 * @arg attrtype Attribute type. 228 * @arg value Numeric value. 229 */ 230 #define NLA_PUT_U32(msg, attrtype, value) \ 231 NLA_PUT_TYPE(msg, uint32_t, attrtype, value) 232 233 /** 234 * Add 64 bit signed integer attribute to netlink message. 235 * @arg msg Netlink message. 236 * @arg attrtype Attribute type. 237 * @arg value Numeric value. 238 */ 239 #define NLA_PUT_S64(msg, attrtype, value) \ 240 NLA_PUT_TYPE(msg, int64_t, attrtype, value) 241 242 /** 243 * Add 64 bit integer attribute to netlink message. 244 * @arg msg Netlink message. 245 * @arg attrtype Attribute type. 246 * @arg value Numeric value. 247 */ 248 #define NLA_PUT_U64(msg, attrtype, value) \ 249 NLA_PUT_TYPE(msg, uint64_t, attrtype, value) 250 251 /** 252 * Add string attribute to netlink message. 253 * @arg msg Netlink message. 254 * @arg attrtype Attribute type. 255 * @arg value NUL terminated character string. 256 */ 257 #define NLA_PUT_STRING(msg, attrtype, value) \ 258 NLA_PUT(msg, attrtype, (int) strlen(value) + 1, value) 259 260 /** 261 * Add flag attribute to netlink message. 262 * @arg msg Netlink message. 263 * @arg attrtype Attribute type. 264 */ 265 #define NLA_PUT_FLAG(msg, attrtype) \ 266 NLA_PUT(msg, attrtype, 0, NULL) 267 268 /** 269 * Add msecs attribute to netlink message. 270 * @arg msg Netlink message. 271 * @arg attrtype Attribute type. 272 * @arg msecs Numeric value in micro seconds. 273 */ 274 #define NLA_PUT_MSECS(msg, attrtype, msecs) \ 275 NLA_PUT_U64(msg, attrtype, msecs) 276 277 /** 278 * Add address attribute to netlink message. 279 * @arg msg Netlink message. 280 * @arg attrtype Attribute type. 281 * @arg addr Abstract address object. 282 */ 283 #define NLA_PUT_ADDR(msg, attrtype, addr) \ 284 NLA_PUT(msg, attrtype, nl_addr_get_len(addr), \ 285 nl_addr_get_binary_addr(addr)) 286 287 /** 288 * Add abstract data attribute to netlink message. 289 * @arg msg Netlink message. 290 * @arg attrtype Attribute type. 291 * @arg data Abstract data object. 292 */ 293 #define NLA_PUT_DATA(msg, attrtype, data) \ 294 NLA_PUT(msg, attrtype, nl_data_get_size(data), \ 295 nl_data_get(data)) 296 297 /** @} */ 298 299 /** 300 * @name Iterators 301 * @{ 302 */ 303 304 /** 305 * @ingroup attr 306 * Iterate over a stream of attributes 307 * @arg pos loop counter, set to current attribute 308 * @arg head head of attribute stream 309 * @arg len length of attribute stream 310 * @arg rem initialized to len, holds bytes currently remaining in stream 311 */ 312 #define nla_for_each_attr(pos, head, len, rem) \ 313 for (pos = head, rem = len; \ 314 nla_ok(pos, rem); \ 315 pos = nla_next(pos, &(rem))) 316 317 /** 318 * @ingroup attr 319 * Iterate over a stream of nested attributes 320 * @arg pos loop counter, set to current attribute 321 * @arg nla attribute containing the nested attributes 322 * @arg rem initialized to len, holds bytes currently remaining in stream 323 */ 324 #define nla_for_each_nested(pos, nla, rem) \ 325 for (pos = (struct nlattr *) nla_data(nla), rem = nla_len(nla); \ 326 nla_ok(pos, rem); \ 327 pos = nla_next(pos, &(rem))) 328 329 /** @} */ 330 331 #ifdef __cplusplus 332 } 333 #endif 334 335 #endif 336