LXR linux/include/linux/genl_magic

   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
  23extern int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void);
  24extern 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
  66static 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
 136enum {
 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
 150enum {
 151#include GENL_MAGIC_INCLUDE_FILE
 152};
 153
 154#undef GENL_struct
 155#define GENL_struct(tag_name, tag_number, s_name, s_fields)     \
 156enum {                                                          \
 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
 190static 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
 209static 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)             \
 220static 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)             \
 251struct 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)             \
 268enum {                                                                  \
 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 */
 286