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/genetlink.h>
  18 #include <linux/types.h>
  19
  20 #define CONCAT__(a,b)   a ## b
  21 #define CONCAT_(a,b)    CONCAT__(a,b)
  22
  23 extern int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void);
  24 extern void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void);
  25
  26 /*
  27  * Extension of genl attribute validation policies                      {{{2
  28  */
  29
  30 /*
  31  * @DRBD_GENLA_F_MANDATORY: By default, netlink ignores attributes it does not
  32  * know about.  This flag can be set in nlattr->nla_type to indicate that this
  33  * attribute must not be ignored.
  34  *
  35  * We check and remove this flag in drbd_nla_check_mandatory() before
  36  * validating the attribute types and lengths via nla_parse_nested().
  37  */
  38 #define DRBD_GENLA_F_MANDATORY (1 << 14)
  39
  40 /*
  41  * Flags specific to drbd and not visible at the netlink layer, used in
  42  * <struct>_from_attrs and <struct>_to_skb:
  43  *
  44  * @DRBD_F_REQUIRED: Attribute is required; a request without this attribute is
  45  * invalid.
  46  *
  47  * @DRBD_F_SENSITIVE: Attribute includes sensitive information and must not be
  48  * included in unpriviledged get requests or broadcasts.
  49  *
  50  * @DRBD_F_INVARIANT: Attribute is set when an object is initially created, but
  51  * cannot subsequently be changed.
  52  */
  53 #define DRBD_F_REQUIRED (1 << 0)
  54 #define DRBD_F_SENSITIVE (1 << 1)
  55 #define DRBD_F_INVARIANT (1 << 2)
  56
  57 #define __nla_type(x)   ((__u16)((x) & NLA_TYPE_MASK & ~DRBD_GENLA_F_MANDATORY))
  58
  59 /*                                                                      }}}1
  60  * MAGIC
  61  * multi-include macro expansion magic starts here
  62  */
  63
  64 /* MAGIC helpers                                                        {{{2 */
  65
  66 static inline int nla_put_u64_0pad(struct sk_buff *skb, int attrtype, u64 value)
  67 {
  68         return nla_put_64bit(skb, attrtype, sizeof(u64), &value, 0);
  69 }
  70
  71 /* possible field types */
  72 #define __flg_field(attr_nr, attr_flag, name) \
  73         __field(attr_nr, attr_flag, name, NLA_U8, char, \
  74                         nla_get_u8, nla_put_u8, false)
  75 #define __u8_field(attr_nr, attr_flag, name)    \
  76         __field(attr_nr, attr_flag, name, NLA_U8, unsigned char, \
  77                         nla_get_u8, nla_put_u8, false)
  78 #define __u16_field(attr_nr, attr_flag, name)   \
  79         __field(attr_nr, attr_flag, name, NLA_U16, __u16, \
  80                         nla_get_u16, nla_put_u16, false)
  81 #define __u32_field(attr_nr, attr_flag, name)   \
  82         __field(attr_nr, attr_flag, name, NLA_U32, __u32, \
  83                         nla_get_u32, nla_put_u32, false)
  84 #define __s32_field(attr_nr, attr_flag, name)   \
  85         __field(attr_nr, attr_flag, name, NLA_U32, __s32, \
  86                         nla_get_u32, nla_put_u32, true)
  87 #define __u64_field(attr_nr, attr_flag, name)   \
  88         __field(attr_nr, attr_flag, name, NLA_U64, __u64, \
  89                         nla_get_u64, nla_put_u64_0pad, false)
  90 #define __str_field(attr_nr, attr_flag, name, maxlen) \
  91         __array(attr_nr, attr_flag, name, NLA_NUL_STRING, char, maxlen, \
  92                         nla_strscpy, nla_put, false)
  93 #define __bin_field(attr_nr, attr_flag, name, maxlen) \
  94         __array(attr_nr, attr_flag, name, NLA_BINARY, char, maxlen, \
  95                         nla_memcpy, nla_put, false)
  96
  97 /* fields with default values */
  98 #define __flg_field_def(attr_nr, attr_flag, name, default) \
  99         __flg_field(attr_nr, attr_flag, name)
 100 #define __u32_field_def(attr_nr, attr_flag, name, default) \
 101         __u32_field(attr_nr, attr_flag, name)
 102 #define __s32_field_def(attr_nr, attr_flag, name, default) \
 103         __s32_field(attr_nr, attr_flag, name)
 104 #define __str_field_def(attr_nr, attr_flag, name, maxlen) \
 105         __str_field(attr_nr, attr_flag, name, maxlen)
 106
 107 #define GENL_op_init(args...)   args
 108 #define GENL_doit(handler)              \
 109         .doit = handler,                \
 110         .flags = GENL_ADMIN_PERM,
 111 #define GENL_dumpit(handler)            \
 112         .dumpit = handler,              \
 113         .flags = GENL_ADMIN_PERM,
 114
 115 /*                                                                      }}}1
 116  * Magic: define the enum symbols for genl_ops
 117  * Magic: define the enum symbols for top level attributes
 118  * Magic: define the enum symbols for nested attributes
 119  *                                                                      {{{2
 120  */
 121
 122 #undef GENL_struct
 123 #define GENL_struct(tag_name, tag_number, s_name, s_fields)
 124
 125 #undef GENL_mc_group
 126 #define GENL_mc_group(group)
 127
 128 #undef GENL_notification
 129 #define GENL_notification(op_name, op_num, mcast_group, tla_list)       \
 130         op_name = op_num,
 131
 132 #undef GENL_op
 133 #define GENL_op(op_name, op_num, handler, tla_list)                     \
 134         op_name = op_num,
 135
 136 enum {
 137 #include GENL_MAGIC_INCLUDE_FILE
 138 };
 139
 140 #undef GENL_notification
 141 #define GENL_notification(op_name, op_num, mcast_group, tla_list)
 142
 143 #undef GENL_op
 144 #define GENL_op(op_name, op_num, handler, attr_list)
 145
 146 #undef GENL_struct
 147 #define GENL_struct(tag_name, tag_number, s_name, s_fields) \
 148                 tag_name = tag_number,
 149
 150 enum {
 151 #include GENL_MAGIC_INCLUDE_FILE
 152 };
 153
 154 #undef GENL_struct
 155 #define GENL_struct(tag_name, tag_number, s_name, s_fields)     \
 156 enum {                                                          \
 157         s_fields                                                \
 158 };
 159
 160 #undef __field
 161 #define __field(attr_nr, attr_flag, name, nla_type, type,       \
 162                 __get, __put, __is_signed)                      \
 163         T_ ## name = (__u16)(attr_nr | ((attr_flag) & DRBD_GENLA_F_MANDATORY)),
 164
 165 #undef __array
 166 #define __array(attr_nr, attr_flag, name, nla_type, type,       \
 167                 maxlen, __get, __put, __is_signed)              \
 168         T_ ## name = (__u16)(attr_nr | ((attr_flag) & DRBD_GENLA_F_MANDATORY)),
 169
 170 #include GENL_MAGIC_INCLUDE_FILE
 171
 172 /*                                                                      }}}1
 173  * Magic: compile time assert unique numbers for operations
 174  * Magic: -"- unique numbers for top level attributes
 175  * Magic: -"- unique numbers for nested attributes
 176  *                                                                      {{{2
 177  */
 178
 179 #undef GENL_struct
 180 #define GENL_struct(tag_name, tag_number, s_name, s_fields)
 181
 182 #undef GENL_op
 183 #define GENL_op(op_name, op_num, handler, attr_list)    \
 184         case op_name:
 185
 186 #undef GENL_notification
 187 #define GENL_notification(op_name, op_num, mcast_group, tla_list)       \
 188         case op_name:
 189
 190 static inline void ct_assert_unique_operations(void)
 191 {
 192         switch (0) {
 193 #include GENL_MAGIC_INCLUDE_FILE
 194         case 0:
 195                 ;
 196         }
 197 }
 198
 199 #undef GENL_op
 200 #define GENL_op(op_name, op_num, handler, attr_list)
 201
 202 #undef GENL_notification
 203 #define GENL_notification(op_name, op_num, mcast_group, tla_list)
 204
 205 #undef GENL_struct
 206 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 207                 case tag_number:
 208
 209 static inline void ct_assert_unique_top_level_attributes(void)
 210 {
 211         switch (0) {
 212 #include GENL_MAGIC_INCLUDE_FILE
 213         case 0:
 214                 ;
 215         }
 216 }
 217
 218 #undef GENL_struct
 219 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 220 static inline void ct_assert_unique_ ## s_name ## _attributes(void)     \
 221 {                                                                       \
 222         switch (0) {                                                    \
 223         s_fields                                                        \
 224         case 0:                                                         \
 225                         ;                                               \
 226         }                                                               \
 227 }
 228
 229 #undef __field
 230 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
 231                 __is_signed)                                            \
 232         case attr_nr:
 233
 234 #undef __array
 235 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,       \
 236                 __get, __put, __is_signed)                              \
 237         case attr_nr:
 238
 239 #include GENL_MAGIC_INCLUDE_FILE
 240
 241 /*                                                                      }}}1
 242  * Magic: declare structs
 243  * struct <name> {
 244  *      fields
 245  * };
 246  *                                                                      {{{2
 247  */
 248
 249 #undef GENL_struct
 250 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 251 struct s_name { s_fields };
 252
 253 #undef __field
 254 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
 255                 __is_signed)                                            \
 256         type name;
 257
 258 #undef __array
 259 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,       \
 260                 __get, __put, __is_signed)                              \
 261         type name[maxlen];      \
 262         __u32 name ## _len;
 263
 264 #include GENL_MAGIC_INCLUDE_FILE
 265
 266 #undef GENL_struct
 267 #define GENL_struct(tag_name, tag_number, s_name, s_fields)             \
 268 enum {                                                                  \
 269         s_fields                                                        \
 270 };
 271
 272 #undef __field
 273 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
 274                 is_signed)                                              \
 275         F_ ## name ## _IS_SIGNED = is_signed,
 276
 277 #undef __array
 278 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,       \
 279                 __get, __put, is_signed)                                \
 280         F_ ## name ## _IS_SIGNED = is_signed,
 281
 282 #include GENL_MAGIC_INCLUDE_FILE
 283
 284 /* }}}1 */
 285 #endif /* GENL_MAGIC_STRUCT_H */