xref: /linux/include/linux/genl_magic_struct.h (revision 7fe6ac157b7e15c8976bd62ad7cb98e248884e83)
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/types.h>
19 #include <net/genetlink.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  * Flags specific to drbd and not visible at the netlink layer, used in
30  * <struct>_from_attrs and <struct>_to_skb:
31  *
32  * @DRBD_F_REQUIRED: Attribute is required; a request without this attribute is
33  * invalid.
34  *
35  * @DRBD_F_SENSITIVE: Attribute includes sensitive information and must not be
36  * included in unpriviledged get requests or broadcasts.
37  *
38  * @DRBD_F_INVARIANT: Attribute is set when an object is initially created, but
39  * cannot subsequently be changed.
40  */
41 #define DRBD_F_REQUIRED (1 << 0)
42 #define DRBD_F_SENSITIVE (1 << 1)
43 #define DRBD_F_INVARIANT (1 << 2)
44 
45 
46 /*									}}}1
47  * MAGIC
48  * multi-include macro expansion magic starts here
49  */
50 
51 /* MAGIC helpers							{{{2 */
52 
nla_put_u64_0pad(struct sk_buff * skb,int attrtype,u64 value)53 static inline int nla_put_u64_0pad(struct sk_buff *skb, int attrtype, u64 value)
54 {
55 	return nla_put_64bit(skb, attrtype, sizeof(u64), &value, 0);
56 }
57 
58 /* possible field types */
59 #define __flg_field(attr_nr, attr_flag, name) \
60 	__field(attr_nr, attr_flag, name, NLA_U8, char, \
61 			nla_get_u8, nla_put_u8, false)
62 #define __u8_field(attr_nr, attr_flag, name)	\
63 	__field(attr_nr, attr_flag, name, NLA_U8, unsigned char, \
64 			nla_get_u8, nla_put_u8, false)
65 #define __u16_field(attr_nr, attr_flag, name)	\
66 	__field(attr_nr, attr_flag, name, NLA_U16, __u16, \
67 			nla_get_u16, nla_put_u16, false)
68 #define __u32_field(attr_nr, attr_flag, name)	\
69 	__field(attr_nr, attr_flag, name, NLA_U32, __u32, \
70 			nla_get_u32, nla_put_u32, false)
71 #define __s32_field(attr_nr, attr_flag, name)	\
72 	__field(attr_nr, attr_flag, name, NLA_U32, __s32, \
73 			nla_get_u32, nla_put_u32, true)
74 #define __u64_field(attr_nr, attr_flag, name)	\
75 	__field(attr_nr, attr_flag, name, NLA_U64, __u64, \
76 			nla_get_u64, nla_put_u64_0pad, false)
77 #define __str_field(attr_nr, attr_flag, name, maxlen) \
78 	__array(attr_nr, attr_flag, name, NLA_NUL_STRING, char, maxlen, \
79 			nla_strscpy, nla_put, false)
80 #define __bin_field(attr_nr, attr_flag, name, maxlen) \
81 	__array(attr_nr, attr_flag, name, NLA_BINARY, char, maxlen, \
82 			nla_memcpy, nla_put, false)
83 
84 /* fields with default values */
85 #define __flg_field_def(attr_nr, attr_flag, name, default) \
86 	__flg_field(attr_nr, attr_flag, name)
87 #define __u32_field_def(attr_nr, attr_flag, name, default) \
88 	__u32_field(attr_nr, attr_flag, name)
89 #define __s32_field_def(attr_nr, attr_flag, name, default) \
90 	__s32_field(attr_nr, attr_flag, name)
91 #define __str_field_def(attr_nr, attr_flag, name, maxlen) \
92 	__str_field(attr_nr, attr_flag, name, maxlen)
93 
94 #define GENL_op_init(args...)	args
95 #define GENL_doit(handler)		\
96 	.doit = handler,		\
97 	.flags = GENL_ADMIN_PERM,
98 #define GENL_dumpit(handler)		\
99 	.dumpit = handler,		\
100 	.flags = GENL_ADMIN_PERM,
101 
102 /*									}}}1
103  * Magic: define the enum symbols for genl_ops
104  * Magic: define the enum symbols for top level attributes
105  * Magic: define the enum symbols for nested attributes
106  *									{{{2
107  */
108 
109 #undef GENL_struct
110 #define GENL_struct(tag_name, tag_number, s_name, s_fields)
111 
112 #undef GENL_mc_group
113 #define GENL_mc_group(group)
114 
115 #undef GENL_notification
116 #define GENL_notification(op_name, op_num, mcast_group, tla_list)	\
117 	op_name = op_num,
118 
119 #undef GENL_op
120 #define GENL_op(op_name, op_num, handler, tla_list)			\
121 	op_name = op_num,
122 
123 enum {
124 #include GENL_MAGIC_INCLUDE_FILE
125 };
126 
127 #undef GENL_notification
128 #define GENL_notification(op_name, op_num, mcast_group, tla_list)
129 
130 #undef GENL_op
131 #define GENL_op(op_name, op_num, handler, attr_list)
132 
133 #undef GENL_struct
134 #define GENL_struct(tag_name, tag_number, s_name, s_fields) \
135 		tag_name = tag_number,
136 
137 enum {
138 #include GENL_MAGIC_INCLUDE_FILE
139 };
140 
141 #undef GENL_struct
142 #define GENL_struct(tag_name, tag_number, s_name, s_fields)	\
143 enum {								\
144 	s_fields						\
145 };
146 
147 #undef __field
148 #define __field(attr_nr, attr_flag, name, nla_type, type,	\
149 		__get, __put, __is_signed)			\
150 	T_ ## name = (__u16)(attr_nr),
151 
152 #undef __array
153 #define __array(attr_nr, attr_flag, name, nla_type, type,	\
154 		maxlen, __get, __put, __is_signed)		\
155 	T_ ## name = (__u16)(attr_nr),
156 
157 #include GENL_MAGIC_INCLUDE_FILE
158 
159 /*									}}}1
160  * Magic: compile time assert unique numbers for operations
161  * Magic: -"- unique numbers for top level attributes
162  * Magic: -"- unique numbers for nested attributes
163  *									{{{2
164  */
165 
166 #undef GENL_struct
167 #define GENL_struct(tag_name, tag_number, s_name, s_fields)
168 
169 #undef GENL_op
170 #define GENL_op(op_name, op_num, handler, attr_list)	\
171 	case op_name:
172 
173 #undef GENL_notification
174 #define GENL_notification(op_name, op_num, mcast_group, tla_list)	\
175 	case op_name:
176 
ct_assert_unique_operations(void)177 static inline void ct_assert_unique_operations(void)
178 {
179 	switch (0) {
180 #include GENL_MAGIC_INCLUDE_FILE
181 	case 0:
182 		;
183 	}
184 }
185 
186 #undef GENL_op
187 #define GENL_op(op_name, op_num, handler, attr_list)
188 
189 #undef GENL_notification
190 #define GENL_notification(op_name, op_num, mcast_group, tla_list)
191 
192 #undef GENL_struct
193 #define GENL_struct(tag_name, tag_number, s_name, s_fields)		\
194 		case tag_number:
195 
ct_assert_unique_top_level_attributes(void)196 static inline void ct_assert_unique_top_level_attributes(void)
197 {
198 	switch (0) {
199 #include GENL_MAGIC_INCLUDE_FILE
200 	case 0:
201 		;
202 	}
203 }
204 
205 #undef GENL_struct
206 #define GENL_struct(tag_name, tag_number, s_name, s_fields)		\
207 static inline void ct_assert_unique_ ## s_name ## _attributes(void)	\
208 {									\
209 	switch (0) {							\
210 	s_fields							\
211 	case 0:								\
212 			;						\
213 	}								\
214 }
215 
216 #undef __field
217 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put,	\
218 		__is_signed)						\
219 	case attr_nr:
220 
221 #undef __array
222 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,	\
223 		__get, __put, __is_signed)				\
224 	case attr_nr:
225 
226 #include GENL_MAGIC_INCLUDE_FILE
227 
228 /*									}}}1
229  * Magic: declare structs
230  * struct <name> {
231  *	fields
232  * };
233  *									{{{2
234  */
235 
236 #undef GENL_struct
237 #define GENL_struct(tag_name, tag_number, s_name, s_fields)		\
238 struct s_name { s_fields };
239 
240 #undef __field
241 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put,	\
242 		__is_signed)						\
243 	type name;
244 
245 #undef __array
246 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,	\
247 		__get, __put, __is_signed)				\
248 	type name[maxlen];	\
249 	__u32 name ## _len;
250 
251 #include GENL_MAGIC_INCLUDE_FILE
252 
253 #undef GENL_struct
254 #define GENL_struct(tag_name, tag_number, s_name, s_fields)		\
255 enum {									\
256 	s_fields							\
257 };
258 
259 #undef __field
260 #define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put,	\
261 		is_signed)						\
262 	F_ ## name ## _IS_SIGNED = is_signed,
263 
264 #undef __array
265 #define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,	\
266 		__get, __put, is_signed)				\
267 	F_ ## name ## _IS_SIGNED = is_signed,
268 
269 #include GENL_MAGIC_INCLUDE_FILE
270 
271 /* }}}1 */
272 #endif /* GENL_MAGIC_STRUCT_H */
273