1 #ifndef GENL_MAGIC_STRUCT_H 2 #define GENL_MAGIC_STRUCT_H 3 4 #ifndef GENL_MAGIC_FAMILY 5 # error "you need to define GENL_MAGIC_FAMILY before inclusion" 6 #endif 7 8 #ifndef GENL_MAGIC_VERSION 9 # error "you need to define GENL_MAGIC_VERSION before inclusion" 10 #endif 11 12 #ifndef GENL_MAGIC_INCLUDE_FILE 13 # error "you need to define GENL_MAGIC_INCLUDE_FILE before inclusion" 14 #endif 15 16 #include <linux/genetlink.h> 17 #include <linux/types.h> 18 19 #define CONCAT__(a,b) a ## b 20 #define CONCAT_(a,b) CONCAT__(a,b) 21 22 extern int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void); 23 extern void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void); 24 25 /* 26 * Extension of genl attribute validation policies {{{2 27 */ 28 29 /** 30 * GENLA_F_FLAGS - policy type flags to ease compatible ABI evolvement 31 * 32 * @GENLA_F_REQUIRED: attribute has to be present, or message is considered invalid. 33 * Adding new REQUIRED attributes breaks ABI compatibility, so don't do that. 34 * 35 * @GENLA_F_MANDATORY: if present, receiver _must_ understand it. 36 * Without this, unknown attributes (> maxtype) are _silently_ ignored 37 * by validate_nla(). 38 * 39 * To be used for API extensions, so older kernel can reject requests for not 40 * yet implemented features, if newer userland tries to use them even though 41 * the genl_family version clearly indicates they are not available. 42 * 43 * @GENLA_F_MAY_IGNORE: To clearly document the fact, for good measure. 44 * To be used for API extensions for things that have sane defaults, 45 * so newer userland can still talk to older kernel, knowing it will 46 * silently ignore these attributes if not yet known. 47 * 48 * NOTE: These flags overload 49 * NLA_F_NESTED (1 << 15) 50 * NLA_F_NET_BYTEORDER (1 << 14) 51 * from linux/netlink.h, which are not useful for validate_nla(): 52 * NET_BYTEORDER is not used anywhere, and NESTED would be specified by setting 53 * .type = NLA_NESTED in the appropriate policy. 54 * 55 * See also: nla_type() 56 */ 57 enum { 58 GENLA_F_MAY_IGNORE = 0, 59 GENLA_F_MANDATORY = 1 << 14, 60 GENLA_F_REQUIRED = 1 << 15, 61 62 /* Below will not be present in the __u16 .nla_type, but can be 63 * triggered on in <struct>_to_skb resp. <struct>_from_attrs */ 64 65 /* To exclude "sensitive" information from broadcasts, or on 66 * unpriviledged get requests. This is useful because genetlink 67 * multicast groups can be listened in on by anyone. */ 68 GENLA_F_SENSITIVE = 1 << 16, 69 70 /* INVARIAN options cannot be changed at runtime. 71 * Useful to share an attribute policy and struct definition, 72 * between some "create" and "change" commands, 73 * but disallow certain fields to be changed online. 74 */ 75 GENLA_F_INVARIANT = 1 << 17, 76 }; 77 78 #define __nla_type(x) ((__u16)((__u16)(x) & (__u16)NLA_TYPE_MASK)) 79 80 /* }}}1 81 * MAGIC 82 * multi-include macro expansion magic starts here 83 */ 84 85 /* MAGIC helpers {{{2 */ 86 87 /* possible field types */ 88 #define __flg_field(attr_nr, attr_flag, name) \ 89 __field(attr_nr, attr_flag, name, NLA_FLAG, char, \ 90 nla_get_flag, __nla_put_flag) 91 #define __u8_field(attr_nr, attr_flag, name) \ 92 __field(attr_nr, attr_flag, name, NLA_U8, unsigned char, \ 93 nla_get_u8, NLA_PUT_U8) 94 #define __u16_field(attr_nr, attr_flag, name) \ 95 __field(attr_nr, attr_flag, name, NLA_U16, __u16, \ 96 nla_get_u16, NLA_PUT_U16) 97 #define __u32_field(attr_nr, attr_flag, name) \ 98 __field(attr_nr, attr_flag, name, NLA_U32, __u32, \ 99 nla_get_u32, NLA_PUT_U32) 100 #define __u64_field(attr_nr, attr_flag, name) \ 101 __field(attr_nr, attr_flag, name, NLA_U64, __u64, \ 102 nla_get_u64, NLA_PUT_U64) 103 #define __str_field(attr_nr, attr_flag, name, maxlen) \ 104 __array(attr_nr, attr_flag, name, NLA_NUL_STRING, char, maxlen, \ 105 nla_strlcpy, NLA_PUT) 106 #define __bin_field(attr_nr, attr_flag, name, maxlen) \ 107 __array(attr_nr, attr_flag, name, NLA_BINARY, char, maxlen, \ 108 nla_memcpy, NLA_PUT) 109 110 /* fields with default values */ 111 #define __flg_field_def(attr_nr, attr_flag, name, default) \ 112 __flg_field(attr_nr, attr_flag, name) 113 #define __u32_field_def(attr_nr, attr_flag, name, default) \ 114 __u32_field(attr_nr, attr_flag, name) 115 #define __str_field_def(attr_nr, attr_flag, name, maxlen) \ 116 __str_field(attr_nr, attr_flag, name, maxlen) 117 118 #define __nla_put_flag(skb, attrtype, value) \ 119 do { \ 120 if (value) \ 121 NLA_PUT_FLAG(skb, attrtype); \ 122 } while (0) 123 124 #define GENL_op_init(args...) args 125 #define GENL_doit(handler) \ 126 .doit = handler, \ 127 .flags = GENL_ADMIN_PERM, 128 #define GENL_dumpit(handler) \ 129 .dumpit = handler, \ 130 .flags = GENL_ADMIN_PERM, 131 132 /* }}}1 133 * Magic: define the enum symbols for genl_ops 134 * Magic: define the enum symbols for top level attributes 135 * Magic: define the enum symbols for nested attributes 136 * {{{2 137 */ 138 139 #undef GENL_struct 140 #define GENL_struct(tag_name, tag_number, s_name, s_fields) 141 142 #undef GENL_mc_group 143 #define GENL_mc_group(group) 144 145 #undef GENL_notification 146 #define GENL_notification(op_name, op_num, mcast_group, tla_list) \ 147 op_name = op_num, 148 149 #undef GENL_op 150 #define GENL_op(op_name, op_num, handler, tla_list) \ 151 op_name = op_num, 152 153 enum { 154 #include GENL_MAGIC_INCLUDE_FILE 155 }; 156 157 #undef GENL_notification 158 #define GENL_notification(op_name, op_num, mcast_group, tla_list) 159 160 #undef GENL_op 161 #define GENL_op(op_name, op_num, handler, attr_list) 162 163 #undef GENL_struct 164 #define GENL_struct(tag_name, tag_number, s_name, s_fields) \ 165 tag_name = tag_number, 166 167 enum { 168 #include GENL_MAGIC_INCLUDE_FILE 169 }; 170 171 #undef GENL_struct 172 #define GENL_struct(tag_name, tag_number, s_name, s_fields) \ 173 enum { \ 174 s_fields \ 175 }; 176 177 #undef __field 178 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \ 179 T_ ## name = (__u16)(attr_nr | attr_flag), 180 181 #undef __array 182 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \ 183 T_ ## name = (__u16)(attr_nr | attr_flag), 184 185 #include GENL_MAGIC_INCLUDE_FILE 186 187 /* }}}1 188 * Magic: compile time assert unique numbers for operations 189 * Magic: -"- unique numbers for top level attributes 190 * Magic: -"- unique numbers for nested attributes 191 * {{{2 192 */ 193 194 #undef GENL_struct 195 #define GENL_struct(tag_name, tag_number, s_name, s_fields) 196 197 #undef GENL_op 198 #define GENL_op(op_name, op_num, handler, attr_list) \ 199 case op_name: 200 201 #undef GENL_notification 202 #define GENL_notification(op_name, op_num, mcast_group, tla_list) \ 203 case op_name: 204 205 static inline void ct_assert_unique_operations(void) 206 { 207 switch (0) { 208 #include GENL_MAGIC_INCLUDE_FILE 209 ; 210 } 211 } 212 213 #undef GENL_op 214 #define GENL_op(op_name, op_num, handler, attr_list) 215 216 #undef GENL_notification 217 #define GENL_notification(op_name, op_num, mcast_group, tla_list) 218 219 #undef GENL_struct 220 #define GENL_struct(tag_name, tag_number, s_name, s_fields) \ 221 case tag_number: 222 223 static inline void ct_assert_unique_top_level_attributes(void) 224 { 225 switch (0) { 226 #include GENL_MAGIC_INCLUDE_FILE 227 ; 228 } 229 } 230 231 #undef GENL_struct 232 #define GENL_struct(tag_name, tag_number, s_name, s_fields) \ 233 static inline void ct_assert_unique_ ## s_name ## _attributes(void) \ 234 { \ 235 switch (0) { \ 236 s_fields \ 237 ; \ 238 } \ 239 } 240 241 #undef __field 242 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \ 243 case attr_nr: 244 245 #undef __array 246 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \ 247 case attr_nr: 248 249 #include GENL_MAGIC_INCLUDE_FILE 250 251 /* }}}1 252 * Magic: declare structs 253 * struct <name> { 254 * fields 255 * }; 256 * {{{2 257 */ 258 259 #undef GENL_struct 260 #define GENL_struct(tag_name, tag_number, s_name, s_fields) \ 261 struct s_name { s_fields }; 262 263 #undef __field 264 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \ 265 type name; 266 267 #undef __array 268 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \ 269 type name[maxlen]; \ 270 __u32 name ## _len; 271 272 #include GENL_MAGIC_INCLUDE_FILE 273 274 /* }}}1 */ 275 #endif /* GENL_MAGIC_STRUCT_H */ 276 /* vim: set foldmethod=marker nofoldenable : */ 277