include/linux/genl_magic_struct.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef GENL_MAGIC_STRUCT_H
   3 #define GENL_MAGIC_STRUCT_H
   4
   5 #ifndef GENL_MAGIC_FAMILY
   6 # error "you need to define GENL_MAGIC_FAMILY before inclusion"
   7 #endif
   8
   9 #ifndef GENL_MAGIC_VERSION
  10 # error "you need to define GENL_MAGIC_VERSION before inclusion"
  11 #endif
  12
  13 #ifndef GENL_MAGIC_INCLUDE_FILE
  14 # error "you need to define GENL_MAGIC_INCLUDE_FILE before inclusion"
  15 #endif
  16
  17 #include <linux/args.h>
  18 #include <linux/genetlink.h>
  19 #include <linux/types.h>
  20
  21 extern int CONCATENATE(GENL_MAGIC_FAMILY, _genl_register)(void);
  22 extern void CONCATENATE(GENL_MAGIC_FAMILY, _genl_unregister)(void);
  23
  24 /*
  25  * Extension of genl attribute validation policies                      {{{2
  26  */
  27
  28 /*
  29  * @DRBD_GENLA_F_MANDATORY: By default, netlink ignores attributes it does not
  30  * know about.  This flag can be set in nlattr->nla_type to indicate that this
  31  * attribute must not be ignored.
  32  *
  33  * We check and remove this flag in drbd_nla_check_mandatory() before
  34  * validating the attribute types and lengths via nla_parse_nested().
  35  */
  36 #define DRBD_GENLA_F_MANDATORY (1 << 14)
  37
  38 /*
  39  * Flags specific to drbd and not visible at the netlink layer, used in
  40  * <struct>_from_attrs and <struct>_to_skb:
  41  *
  42  * @DRBD_F_REQUIRED: Attribute is required; a request without this attribute is
  43  * invalid.
  44  *
  45  * @DRBD_F_SENSITIVE: Attribute includes sensitive information and must not be
  46  * included in unpriviledged get requests or broadcasts.
  47  *
  48  * @DRBD_F_INVARIANT: Attribute is set when an object is initially created, but
  49  * cannot subsequently be changed.
  50  */
  51 #define DRBD_F_REQUIRED (1 << 0)
  52 #define DRBD_F_SENSITIVE (1 << 1)
  53 #define DRBD_F_INVARIANT (1 << 2)
  54
  55 #define __nla_type(x)   ((__u16)((x) & NLA_TYPE_MASK & ~DRBD_GENLA_F_MANDATORY))
  56
  57 /*                                                                      }}}1
  58  * MAGIC
  59  * multi-include macro expansion magic starts here
  60  */
  61
  62 /* MAGIC helpers                                                        {{{2 */
  63
  64 static inline int nla_put_u64_0pad(struct sk_buff *skb, int attrtype, u64 value)
  65 {
  66         return nla_put_64bit(skb, attrtype, sizeof(u64), &value, 0);
  67 }
  68
  69 /* possible field types */
  70 #define __flg_field(attr_nr, attr_flag, name) \
  71         __field(attr_nr, attr_flag, name, NLA_U8, char, \
  72                         nla_get_u8, nla_put_u8, false)
  73 #define __u8_field(attr_nr, attr_flag, name)    \
  74         __field(attr_nr, attr_flag, name, NLA_U8, unsigned char, \
  75                         nla_get_u8, nla_put_u8, false)
  76 #define __u16_field(attr_nr, attr_flag, name)   \
  77         __field(attr_nr, attr_flag, name, NLA_U16, __u16, \
  78                         nla_get_u16, nla_put_u16, false)
  79 #define __u32_field(attr_nr, attr_flag, name)   \
  80         __field(attr_nr, attr_flag, name, NLA_U32, __u32, \
  81                         nla_get_u32, nla_put_u32, false)
  82 #define __s32_field(attr_nr, attr_flag, name)   \
  83         __field(attr_nr, attr_flag, name, NLA_U32, __s32, \
  84                         nla_get_u32, nla_put_u32, true)
  85 #define __u64_field(attr_nr, attr_flag, name)   \
  86         __field(attr_nr, attr_flag, name, NLA_U64, __u64, \
  87                         nla_get_u64, nla_put_u64_0pad, false)
  88 #define __str_field(attr_nr, attr_flag, name, maxlen) \
  89         __array(attr_nr, attr_flag, name, NLA_NUL_STRING, char, maxlen, \
  90                         nla_strscpy, nla_put, false)
  91 #define __bin_field(attr_nr, attr_flag, name, maxlen) \
  92         __array(attr_nr, attr_flag, name, NLA_BINARY, char, maxlen, \
  93                         nla_memcpy, nla_put, false)
  94
  95 /* fields with default values */
  96 #define __flg_field_def(attr_nr, attr_flag, name, default) \
  97         __flg_field(attr_nr, attr_flag, name)
  98 #define __u32_field_def(attr_nr, attr_flag, name, default) \
  99         __u32_field(attr_nr, attr_flag, name)
 100 #define __s32_field_def(attr_nr, attr_flag, name, default) \
 101         __s32_field(attr_nr, attr_flag, name)
 102 #define __str_field_def(attr_nr, attr_flag, name, maxlen) \
 103         __str_field(attr_nr, attr_flag, name, maxlen)
 104
 105 #define GENL_op_init(args...)   args
 106 #define GENL_doit(handler)              \
 107         .doit = handler,                \
 108         .flags = GENL_ADMIN_PERM,
 109 #define GENL_dumpit(handler)            \
 110         .dumpit = handler,              \
 111         .flags = GENL_ADMIN_PERM,
 112
 113 /*                                                                      }}}1
 114  * Magic: define the enum symbols for genl_ops
 115  * Magic: define the enum symbols for top level attributes
 116  * Magic: define the enum symbols for nested attributes
 117  *                                                                      {{{2
 118  */
 119
 120 #undef GENL_struct
 121 #define GENL_struct(tag_name, tag_number, s_name, s_fields)
 122
 123 #undef GENL_mc_group
 124 #define GENL_mc_group(group)
 125
 126 #undef GENL_notification
 127 #define GENL_notification(op_name, op_num, mcast_group, tla_list)       \
 128         op_name = op_num,
 129
 130 #undef GENL_op
 131 #define GENL_op(op_name, op_num, handler, tla_list)                     \
 132         op_name = op_num,
 133
 134 enum {
 135 #include GENL_MAGIC_INCLUDE_FILE
 136 };
 137
 138 #undef GENL_notification
 139 #define GENL_notification(op_name, op_num, mcast_group, tla_list)
 140
 141 #undef GENL_op
 142 #define GENL_op(op_name, op_num, handler, attr_list)
 143
 144 #undef GENL_struct
 145 #define GENL_struct(tag_name, tag_number, s_name, s_fields) \
 146                 tag_name = tag_number,
 147
 148 enum {
 149 #include GENL_MAGIC_INCLUDE_FILE
 150 };
 151
 152 #undef GENL_struct
 153 #define GENL_struct(tag_name, tag_number, s_name, s_fields)     \
 154 enum {                                                          \
 155         s_fields                                                \
 156 };
 157
 158 #undef __field
 159 #define __field(attr_nr, attr_flag, name, nla_type, type,       \
 160                 __get, __put, __is_signed)                      \
 161         T_ ## name = (__u16)(attr_nr | ((attr_flag) & DRBD_GENLA_F_MANDATORY)),
 162
 163 #undef __array
 164 #define __array(attr_nr, attr_flag, name, nla_type, type,       \
 165                 maxlen, __get, __put, __is_signed)              \
 166         T_ ## name = (__u16)(attr_nr | ((attr_flag) & DRBD_GENLA_F_MANDATORY)),
 167
 168 #include GENL_MAGIC_INCLUDE_FILE
 169
 170 /*                                                                      }}}1
 171  * Magic: compile time assert unique numbers for operations
 172  * Magic: -"- unique numbers for top level attributes
 173  * Magic: -"- unique numbers for nested attributes
 174  *                                                                      {{{2
 175  */
 176
 177 #undef GENL_struct
 178 #define GENL_struct(tag_name, tag_number, s_name, s_fields)
 179
 180 #undef GENL_op
 181 #define GENL_op(op_name, op_num, handler, attr_list)    \
 182         case op_name:
 183
 184 #undef GENL_notification
 185 #define GENL_notification(op_name, op_num, mcast_group, tla_list)       \
 186         case op_name:
 187
 188 static inline void ct_assert_unique_operations(void)
 189 {
 190         switch (0) {
 191 #include GENL_MAGIC_INCLUDE_FILE
 192         case 0:
 193                 ;
 194         }
 195 }
 196
 197 #undef GENL_op
 198 #define GENL_op(op_name, op_num, handler, attr_list)
 199
 200 #undef GENL_notification
 201 #define GENL_notification(op_name, op_num, mcast_group, tla_list)
 202
 203 #undef GENL_struct
 204 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 205                 case tag_number:
 206
 207 static inline void ct_assert_unique_top_level_attributes(void)
 208 {
 209         switch (0) {
 210 #include GENL_MAGIC_INCLUDE_FILE
 211         case 0:
 212                 ;
 213         }
 214 }
 215
 216 #undef GENL_struct
 217 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 218 static inline void ct_assert_unique_ ## s_name ## _attributes(void)     \
 219 {                                                                       \
 220         switch (0) {                                                    \
 221         s_fields                                                        \
 222         case 0:                                                         \
 223                         ;                                               \
 224         }                                                               \
 225 }
 226
 227 #undef __field
 228 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
 229                 __is_signed)                                            \
 230         case attr_nr:
 231
 232 #undef __array
 233 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,       \
 234                 __get, __put, __is_signed)                              \
 235         case attr_nr:
 236
 237 #include GENL_MAGIC_INCLUDE_FILE
 238
 239 /*                                                                      }}}1
 240  * Magic: declare structs
 241  * struct <name> {
 242  *      fields
 243  * };
 244  *                                                                      {{{2
 245  */
 246
 247 #undef GENL_struct
 248 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 249 struct s_name { s_fields };
 250
 251 #undef __field
 252 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
 253                 __is_signed)                                            \
 254         type name;
 255
 256 #undef __array
 257 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,       \
 258                 __get, __put, __is_signed)                              \
 259         type name[maxlen];      \
 260         __u32 name ## _len;
 261
 262 #include GENL_MAGIC_INCLUDE_FILE
 263
 264 #undef GENL_struct
 265 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 266 enum {                                                                  \
 267         s_fields                                                        \
 268 };
 269
 270 #undef __field
 271 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
 272                 is_signed)                                              \
 273         F_ ## name ## _IS_SIGNED = is_signed,
 274
 275 #undef __array
 276 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,       \
 277                 __get, __put, is_signed)                                \
 278         F_ ## name ## _IS_SIGNED = is_signed,
 279
 280 #include GENL_MAGIC_INCLUDE_FILE
 281
 282 /* }}}1 */
 283 #endif /* GENL_MAGIC_STRUCT_H */