xref: /linux/include/linux/genl_magic_struct.h (revision 621cde16e49b3ecf7d59a8106a20aaebfb4a59a9)
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  * @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 
nla_put_u64_0pad(struct sk_buff * skb,int attrtype,u64 value)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 
ct_assert_unique_operations(void)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 
ct_assert_unique_top_level_attributes(void)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 */
284