include/linux/genl_magic_struct.h

   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  * NOTE: These flags overload
  44  *   NLA_F_NESTED               (1 << 15)
  45  *   NLA_F_NET_BYTEORDER        (1 << 14)
  46  * from linux/netlink.h, which are not useful for validate_nla():
  47  * NET_BYTEORDER is not used anywhere, and NESTED would be specified by setting
  48  * .type = NLA_NESTED in the appropriate policy.
  49  *
  50  * See also: nla_type()
  51  */
  52 enum {
  53         GENLA_F_MANDATORY       = 1 << 14,
  54         GENLA_F_REQUIRED        = 1 << 15,
  55
  56         /* Below will not be present in the __u16 .nla_type, but can be
  57          * triggered on in <struct>_to_skb resp. <struct>_from_attrs */
  58
  59         /* To exclude "sensitive" information from broadcasts, or on
  60          * unpriviledged get requests.  This is useful because genetlink
  61          * multicast groups can be listened in on by anyone.  */
  62         GENLA_F_SENSITIVE       = 1 << 16,
  63
  64         /* INVARIAN options cannot be changed at runtime.
  65          * Useful to share an attribute policy and struct definition,
  66          * between some "create" and "change" commands,
  67          * but disallow certain fields to be changed online.
  68          */
  69         GENLA_F_INVARIANT       = 1 << 17,
  70 };
  71
  72 #define __nla_type(x)   ((__u16)((__u16)(x) & (__u16)NLA_TYPE_MASK))
  73
  74 /*                                                                      }}}1
  75  * MAGIC
  76  * multi-include macro expansion magic starts here
  77  */
  78
  79 /* MAGIC helpers                                                        {{{2 */
  80
  81 /* possible field types */
  82 #define __flg_field(attr_nr, attr_flag, name) \
  83         __field(attr_nr, attr_flag, name, NLA_U8, char, \
  84                         nla_get_u8, NLA_PUT_U8, false)
  85 #define __u8_field(attr_nr, attr_flag, name)    \
  86         __field(attr_nr, attr_flag, name, NLA_U8, unsigned char, \
  87                         nla_get_u8, NLA_PUT_U8, false)
  88 #define __u16_field(attr_nr, attr_flag, name)   \
  89         __field(attr_nr, attr_flag, name, NLA_U16, __u16, \
  90                         nla_get_u16, NLA_PUT_U16, false)
  91 #define __u32_field(attr_nr, attr_flag, name)   \
  92         __field(attr_nr, attr_flag, name, NLA_U32, __u32, \
  93                         nla_get_u32, NLA_PUT_U32, false)
  94 #define __s32_field(attr_nr, attr_flag, name)   \
  95         __field(attr_nr, attr_flag, name, NLA_U32, __s32, \
  96                         nla_get_u32, NLA_PUT_U32, true)
  97 #define __u64_field(attr_nr, attr_flag, name)   \
  98         __field(attr_nr, attr_flag, name, NLA_U64, __u64, \
  99                         nla_get_u64, NLA_PUT_U64, false)
 100 #define __str_field(attr_nr, attr_flag, name, maxlen) \
 101         __array(attr_nr, attr_flag, name, NLA_NUL_STRING, char, maxlen, \
 102                         nla_strlcpy, NLA_PUT, false)
 103 #define __bin_field(attr_nr, attr_flag, name, maxlen) \
 104         __array(attr_nr, attr_flag, name, NLA_BINARY, char, maxlen, \
 105                         nla_memcpy, NLA_PUT, false)
 106
 107 /* fields with default values */
 108 #define __flg_field_def(attr_nr, attr_flag, name, default) \
 109         __flg_field(attr_nr, attr_flag, name)
 110 #define __u32_field_def(attr_nr, attr_flag, name, default) \
 111         __u32_field(attr_nr, attr_flag, name)
 112 #define __s32_field_def(attr_nr, attr_flag, name, default) \
 113         __s32_field(attr_nr, attr_flag, name)
 114 #define __str_field_def(attr_nr, attr_flag, name, maxlen) \
 115         __str_field(attr_nr, attr_flag, name, maxlen)
 116
 117 #define GENL_op_init(args...)   args
 118 #define GENL_doit(handler)              \
 119         .doit = handler,                \
 120         .flags = GENL_ADMIN_PERM,
 121 #define GENL_dumpit(handler)            \
 122         .dumpit = handler,              \
 123         .flags = GENL_ADMIN_PERM,
 124
 125 /*                                                                      }}}1
 126  * Magic: define the enum symbols for genl_ops
 127  * Magic: define the enum symbols for top level attributes
 128  * Magic: define the enum symbols for nested attributes
 129  *                                                                      {{{2
 130  */
 131
 132 #undef GENL_struct
 133 #define GENL_struct(tag_name, tag_number, s_name, s_fields)
 134
 135 #undef GENL_mc_group
 136 #define GENL_mc_group(group)
 137
 138 #undef GENL_notification
 139 #define GENL_notification(op_name, op_num, mcast_group, tla_list)       \
 140         op_name = op_num,
 141
 142 #undef GENL_op
 143 #define GENL_op(op_name, op_num, handler, tla_list)                     \
 144         op_name = op_num,
 145
 146 enum {
 147 #include GENL_MAGIC_INCLUDE_FILE
 148 };
 149
 150 #undef GENL_notification
 151 #define GENL_notification(op_name, op_num, mcast_group, tla_list)
 152
 153 #undef GENL_op
 154 #define GENL_op(op_name, op_num, handler, attr_list)
 155
 156 #undef GENL_struct
 157 #define GENL_struct(tag_name, tag_number, s_name, s_fields) \
 158                 tag_name = tag_number,
 159
 160 enum {
 161 #include GENL_MAGIC_INCLUDE_FILE
 162 };
 163
 164 #undef GENL_struct
 165 #define GENL_struct(tag_name, tag_number, s_name, s_fields)     \
 166 enum {                                                          \
 167         s_fields                                                \
 168 };
 169
 170 #undef __field
 171 #define __field(attr_nr, attr_flag, name, nla_type, type,       \
 172                 __get, __put, __is_signed)                      \
 173         T_ ## name = (__u16)(attr_nr | attr_flag),
 174
 175 #undef __array
 176 #define __array(attr_nr, attr_flag, name, nla_type, type,       \
 177                 maxlen, __get, __put, __is_signed)              \
 178         T_ ## name = (__u16)(attr_nr | attr_flag),
 179
 180 #include GENL_MAGIC_INCLUDE_FILE
 181
 182 /*                                                                      }}}1
 183  * Magic: compile time assert unique numbers for operations
 184  * Magic: -"- unique numbers for top level attributes
 185  * Magic: -"- unique numbers for nested attributes
 186  *                                                                      {{{2
 187  */
 188
 189 #undef GENL_struct
 190 #define GENL_struct(tag_name, tag_number, s_name, s_fields)
 191
 192 #undef GENL_op
 193 #define GENL_op(op_name, op_num, handler, attr_list)    \
 194         case op_name:
 195
 196 #undef GENL_notification
 197 #define GENL_notification(op_name, op_num, mcast_group, tla_list)       \
 198         case op_name:
 199
 200 static inline void ct_assert_unique_operations(void)
 201 {
 202         switch (0) {
 203 #include GENL_MAGIC_INCLUDE_FILE
 204                 ;
 205         }
 206 }
 207
 208 #undef GENL_op
 209 #define GENL_op(op_name, op_num, handler, attr_list)
 210
 211 #undef GENL_notification
 212 #define GENL_notification(op_name, op_num, mcast_group, tla_list)
 213
 214 #undef GENL_struct
 215 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 216                 case tag_number:
 217
 218 static inline void ct_assert_unique_top_level_attributes(void)
 219 {
 220         switch (0) {
 221 #include GENL_MAGIC_INCLUDE_FILE
 222                 ;
 223         }
 224 }
 225
 226 #undef GENL_struct
 227 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 228 static inline void ct_assert_unique_ ## s_name ## _attributes(void)     \
 229 {                                                                       \
 230         switch (0) {                                                    \
 231                 s_fields                                                \
 232                         ;                                               \
 233         }                                                               \
 234 }
 235
 236 #undef __field
 237 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
 238                 __is_signed)                                            \
 239         case attr_nr:
 240
 241 #undef __array
 242 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,       \
 243                 __get, __put, __is_signed)                              \
 244         case attr_nr:
 245
 246 #include GENL_MAGIC_INCLUDE_FILE
 247
 248 /*                                                                      }}}1
 249  * Magic: declare structs
 250  * struct <name> {
 251  *      fields
 252  * };
 253  *                                                                      {{{2
 254  */
 255
 256 #undef GENL_struct
 257 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 258 struct s_name { s_fields };
 259
 260 #undef __field
 261 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
 262                 __is_signed)                                            \
 263         type name;
 264
 265 #undef __array
 266 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,       \
 267                 __get, __put, __is_signed)                              \
 268         type name[maxlen];      \
 269         __u32 name ## _len;
 270
 271 #include GENL_MAGIC_INCLUDE_FILE
 272
 273 #undef GENL_struct
 274 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 275 enum {                                                                  \
 276         s_fields                                                        \
 277 };
 278
 279 #undef __field
 280 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
 281                 is_signed)                                              \
 282         F_ ## name ## _IS_SIGNED = is_signed,
 283
 284 #undef __array
 285 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,       \
 286                 __get, __put, is_signed)                                \
 287         F_ ## name ## _IS_SIGNED = is_signed,
 288
 289 #include GENL_MAGIC_INCLUDE_FILE
 290
 291 /* }}}1 */
 292 #endif /* GENL_MAGIC_STRUCT_H */
 293 /* vim: set foldmethod=marker nofoldenable : */