1 /* 2 * netlink/attr.h Netlink Attributes 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Lesser General Public 6 * License as published by the Free Software Foundation version 2.1 7 * of the License. 8 * 9 * Copyright (c) 2003-2013 Thomas Graf <tgraf@suug.ch> 10 */ 11 12 #ifndef NETLINK_ATTR_H_ 13 #define NETLINK_ATTR_H_ 14 15 #include <netlink/netlink.h> 16 #include <netlink/object.h> 17 #include <netlink/addr.h> 18 #include <netlink/data.h> 19 20 #ifdef __cplusplus 21 extern "C" { 22 #endif 23 24 struct nlattr; 25 26 struct nl_msg; 27 28 /** 29 * @name Basic Attribute Data Types 30 * @{ 31 */ 32 33 /** 34 * @ingroup attr 35 * Basic attribute data types 36 * 37 * See section @core_doc{core_attr_parse,Attribute Parsing} for more details. 38 */ 39 enum { 40 NLA_UNSPEC, /**< Unspecified type, binary data chunk */ 41 NLA_U8, /**< 8 bit integer */ 42 NLA_U16, /**< 16 bit integer */ 43 NLA_U32, /**< 32 bit integer */ 44 NLA_U64, /**< 64 bit integer */ 45 NLA_STRING, /**< NUL terminated character string */ 46 NLA_FLAG, /**< Flag */ 47 NLA_MSECS, /**< Micro seconds (64bit) */ 48 NLA_NESTED, /**< Nested attributes */ 49 NLA_NESTED_COMPAT, 50 NLA_NUL_STRING, 51 NLA_BINARY, 52 NLA_S8, 53 NLA_S16, 54 NLA_S32, 55 NLA_S64, 56 __NLA_TYPE_MAX, 57 }; 58 59 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) 60 61 /** @} */ 62 63 /** 64 * @ingroup attr 65 * Attribute validation policy. 66 * 67 * See section @core_doc{core_attr_parse,Attribute Parsing} for more details. 68 */ 69 struct nla_policy { 70 /** Type of attribute or NLA_UNSPEC */ 71 uint16_t type; 72 73 /** Minimal length of payload required */ 74 uint16_t minlen; 75 76 /** Maximal length of payload allowed */ 77 uint16_t maxlen; 78 }; 79 80 /* Size calculations */ 81 extern int nla_attr_size(int payload); 82 extern int nla_total_size(int payload); 83 extern int nla_padlen(int payload); 84 85 /* Attribute parsing */ 86 extern int nla_type(const struct nlattr *); 87 extern void * nla_data(const struct nlattr *); 88 extern int nla_len(const struct nlattr *); 89 extern int nla_ok(const struct nlattr *, int); 90 extern struct nlattr * nla_next(const struct nlattr *, int *); 91 extern int nla_parse(struct nlattr **, int, struct nlattr *, 92 int, const struct nla_policy *); 93 extern int nla_validate(const struct nlattr *, int, int, 94 const struct nla_policy *); 95 extern struct nlattr * nla_find(const struct nlattr *, int, int); 96 97 /* Helper Functions */ 98 extern int nla_memcpy(void *, const struct nlattr *, int); 99 extern size_t nla_strlcpy(char *, const struct nlattr *, size_t); 100 extern int nla_memcmp(const struct nlattr *, const void *, size_t); 101 extern int nla_strcmp(const struct nlattr *, const char *); 102 103 /* Unspecific attribute */ 104 extern struct nlattr * nla_reserve(struct nl_msg *, int, int); 105 extern int nla_put(struct nl_msg *, int, int, const void *); 106 extern int nla_put_data(struct nl_msg *, int, 107 const struct nl_data *); 108 extern int nla_put_addr(struct nl_msg *, int, struct nl_addr *); 109 110 /* Integer attribute */ 111 extern int8_t nla_get_s8(const struct nlattr *); 112 extern int nla_put_s8(struct nl_msg *, int, int8_t); 113 extern uint8_t nla_get_u8(const struct nlattr *); 114 extern int nla_put_u8(struct nl_msg *, int, uint8_t); 115 extern int16_t nla_get_s16(const struct nlattr *); 116 extern int nla_put_s16(struct nl_msg *, int, int16_t); 117 extern uint16_t nla_get_u16(const struct nlattr *); 118 extern int nla_put_u16(struct nl_msg *, int, uint16_t); 119 extern int32_t nla_get_s32(const struct nlattr *); 120 extern int nla_put_s32(struct nl_msg *, int, int32_t); 121 extern uint32_t nla_get_u32(const struct nlattr *); 122 extern int nla_put_u32(struct nl_msg *, int, uint32_t); 123 extern int64_t nla_get_s64(const struct nlattr *); 124 extern int nla_put_s64(struct nl_msg *, int, int64_t); 125 extern uint64_t nla_get_u64(const struct nlattr *); 126 extern int nla_put_u64(struct nl_msg *, int, uint64_t); 127 128 /* String attribute */ 129 extern char * nla_get_string(const struct nlattr *); 130 extern char * nla_strdup(const struct nlattr *); 131 extern int nla_put_string(struct nl_msg *, int, const char *); 132 133 /* Flag attribute */ 134 extern int nla_get_flag(const struct nlattr *); 135 extern int nla_put_flag(struct nl_msg *, int); 136 137 /* Msec attribute */ 138 extern unsigned long nla_get_msecs(const struct nlattr *); 139 extern int nla_put_msecs(struct nl_msg *, int, unsigned long); 140 141 /* Attribute nesting */ 142 extern int nla_put_nested(struct nl_msg *, int, 143 const struct nl_msg *); 144 extern struct nlattr * nla_nest_start(struct nl_msg *, int); 145 extern int nla_nest_end(struct nl_msg *, struct nlattr *); 146 extern int nla_nest_end_keep_empty(struct nl_msg *, struct nlattr *); 147 extern void nla_nest_cancel(struct nl_msg *, const struct nlattr *); 148 extern int nla_parse_nested(struct nlattr **, int, struct nlattr *, 149 const struct nla_policy *); 150 extern int nla_is_nested(const struct nlattr *); 151 152 /** 153 * @name Attribute Construction (Exception Based) 154 * @{ 155 */ 156 157 /** 158 * @ingroup attr 159 * Add unspecific attribute to netlink message. 160 * @arg msg Netlink message. 161 * @arg attrtype Attribute type. 162 * @arg attrlen Length of attribute payload. 163 * @arg data Head of attribute payload. 164 */ 165 #define NLA_PUT(msg, attrtype, attrlen, data) \ 166 do { \ 167 if (nla_put(msg, attrtype, attrlen, data) < 0) \ 168 goto nla_put_failure; \ 169 } while(0) 170 171 /** 172 * @ingroup attr 173 * Add atomic type attribute to netlink message. 174 * @arg msg Netlink message. 175 * @arg type Atomic type. 176 * @arg attrtype Attribute type. 177 * @arg value Head of attribute payload. 178 */ 179 #define NLA_PUT_TYPE(msg, type, attrtype, value) \ 180 do { \ 181 type __tmp = value; \ 182 NLA_PUT(msg, attrtype, sizeof(type), &__tmp); \ 183 } while(0) 184 185 /** 186 * Add 8 bit signed integer attribute to netlink message. 187 * @arg msg Netlink message. 188 * @arg attrtype Attribute type. 189 * @arg value Numeric value. 190 */ 191 #define NLA_PUT_S8(msg, attrtype, value) \ 192 NLA_PUT_TYPE(msg, int8_t, attrtype, value) 193 194 /** 195 * Add 8 bit integer attribute to netlink message. 196 * @arg msg Netlink message. 197 * @arg attrtype Attribute type. 198 * @arg value Numeric value. 199 */ 200 #define NLA_PUT_U8(msg, attrtype, value) \ 201 NLA_PUT_TYPE(msg, uint8_t, attrtype, value) 202 203 /** 204 * Add 16 bit signed integer attribute to netlink message. 205 * @arg msg Netlink message. 206 * @arg attrtype Attribute type. 207 * @arg value Numeric value. 208 */ 209 #define NLA_PUT_S16(msg, attrtype, value) \ 210 NLA_PUT_TYPE(msg, int16_t, attrtype, value) 211 212 /** 213 * Add 16 bit integer attribute to netlink message. 214 * @arg msg Netlink message. 215 * @arg attrtype Attribute type. 216 * @arg value Numeric value. 217 */ 218 #define NLA_PUT_U16(msg, attrtype, value) \ 219 NLA_PUT_TYPE(msg, uint16_t, attrtype, value) 220 221 /** 222 * Add 32 bit signed integer attribute to netlink message. 223 * @arg msg Netlink message. 224 * @arg attrtype Attribute type. 225 * @arg value Numeric value. 226 */ 227 #define NLA_PUT_S32(msg, attrtype, value) \ 228 NLA_PUT_TYPE(msg, int32_t, attrtype, value) 229 230 /** 231 * Add 32 bit integer attribute to netlink message. 232 * @arg msg Netlink message. 233 * @arg attrtype Attribute type. 234 * @arg value Numeric value. 235 */ 236 #define NLA_PUT_U32(msg, attrtype, value) \ 237 NLA_PUT_TYPE(msg, uint32_t, attrtype, value) 238 239 /** 240 * Add 64 bit signed integer attribute to netlink message. 241 * @arg msg Netlink message. 242 * @arg attrtype Attribute type. 243 * @arg value Numeric value. 244 */ 245 #define NLA_PUT_S64(msg, attrtype, value) \ 246 NLA_PUT_TYPE(msg, int64_t, attrtype, value) 247 248 /** 249 * Add 64 bit integer attribute to netlink message. 250 * @arg msg Netlink message. 251 * @arg attrtype Attribute type. 252 * @arg value Numeric value. 253 */ 254 #define NLA_PUT_U64(msg, attrtype, value) \ 255 NLA_PUT_TYPE(msg, uint64_t, attrtype, value) 256 257 /** 258 * Add string attribute to netlink message. 259 * @arg msg Netlink message. 260 * @arg attrtype Attribute type. 261 * @arg value NUL terminated character string. 262 */ 263 #define NLA_PUT_STRING(msg, attrtype, value) \ 264 NLA_PUT(msg, attrtype, (int) strlen(value) + 1, value) 265 266 /** 267 * Add flag attribute to netlink message. 268 * @arg msg Netlink message. 269 * @arg attrtype Attribute type. 270 */ 271 #define NLA_PUT_FLAG(msg, attrtype) \ 272 NLA_PUT(msg, attrtype, 0, NULL) 273 274 /** 275 * Add msecs attribute to netlink message. 276 * @arg msg Netlink message. 277 * @arg attrtype Attribute type. 278 * @arg msecs Numeric value in micro seconds. 279 */ 280 #define NLA_PUT_MSECS(msg, attrtype, msecs) \ 281 NLA_PUT_U64(msg, attrtype, msecs) 282 283 /** 284 * Add address attribute to netlink message. 285 * @arg msg Netlink message. 286 * @arg attrtype Attribute type. 287 * @arg addr Abstract address object. 288 */ 289 #define NLA_PUT_ADDR(msg, attrtype, addr) \ 290 NLA_PUT(msg, attrtype, nl_addr_get_len(addr), \ 291 nl_addr_get_binary_addr(addr)) 292 293 /** 294 * Add abstract data attribute to netlink message. 295 * @arg msg Netlink message. 296 * @arg attrtype Attribute type. 297 * @arg data Abstract data object. 298 */ 299 #define NLA_PUT_DATA(msg, attrtype, data) \ 300 NLA_PUT(msg, attrtype, nl_data_get_size(data), \ 301 nl_data_get(data)) 302 303 /** @} */ 304 305 /** 306 * @name Iterators 307 * @{ 308 */ 309 310 /** 311 * @ingroup attr 312 * Iterate over a stream of attributes 313 * @arg pos loop counter, set to current attribute 314 * @arg head head of attribute stream 315 * @arg len length of attribute stream 316 * @arg rem initialized to len, holds bytes currently remaining in stream 317 */ 318 #define nla_for_each_attr(pos, head, len, rem) \ 319 for (pos = head, rem = len; \ 320 nla_ok(pos, rem); \ 321 pos = nla_next(pos, &(rem))) 322 323 /** 324 * @ingroup attr 325 * Iterate over a stream of nested attributes 326 * @arg pos loop counter, set to current attribute 327 * @arg nla attribute containing the nested attributes 328 * @arg rem initialized to len, holds bytes currently remaining in stream 329 */ 330 #define nla_for_each_nested(pos, nla, rem) \ 331 for (pos = (struct nlattr *) nla_data(nla), rem = nla_len(nla); \ 332 nla_ok(pos, rem); \ 333 pos = nla_next(pos, &(rem))) 334 335 /** @} */ 336 337 #ifdef __cplusplus 338 } 339 #endif 340 341 #endif 342