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