Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* |
3 | * sysctl.h: General linux system control interface | |
4 | * | |
5 | * Begun 24 March 1995, Stephen Tweedie | |
6 | * | |
7 | **************************************************************** | |
8 | **************************************************************** | |
9 | ** | |
7cc13edc | 10 | ** WARNING: |
1da177e4 | 11 | ** The values in this file are exported to user space via |
7cc13edc EB |
12 | ** the sysctl() binary interface. Do *NOT* change the |
13 | ** numbering of any existing values here, and do not change | |
14 | ** any numbers within any one set of values. If you have to | |
93aec204 | 15 | ** redefine an existing interface, use a new number for it. |
7cc13edc EB |
16 | ** The kernel will then return -ENOTDIR to any application using |
17 | ** the old binary interface. | |
18 | ** | |
1da177e4 LT |
19 | **************************************************************** |
20 | **************************************************************** | |
21 | */ | |
1da177e4 LT |
22 | #ifndef _LINUX_SYSCTL_H |
23 | #define _LINUX_SYSCTL_H | |
24 | ||
d4ed803c | 25 | #include <linux/list.h> |
684adca4 | 26 | #include <linux/rcupdate.h> |
f1ecf068 | 27 | #include <linux/wait.h> |
ac13ac6f | 28 | #include <linux/rbtree.h> |
e79c6a4f | 29 | #include <linux/uidgid.h> |
607ca46e | 30 | #include <uapi/linux/sysctl.h> |
1da177e4 | 31 | |
805b5d5e | 32 | /* For the /proc/sys support */ |
db3f6001 | 33 | struct completion; |
1ff007eb | 34 | struct ctl_table; |
e51b6ba0 | 35 | struct nsproxy; |
d7321cd6 | 36 | struct ctl_table_root; |
f7e6ced4 | 37 | struct ctl_table_header; |
7ec66d06 | 38 | struct ctl_dir; |
f7e6ced4 | 39 | |
eec4844f | 40 | /* Keep the same order as in fs/proc/proc_sysctl.c */ |
78e36f3b XN |
41 | #define SYSCTL_NEG_ONE ((void *)&sysctl_vals[0]) |
42 | #define SYSCTL_ZERO ((void *)&sysctl_vals[1]) | |
43 | #define SYSCTL_ONE ((void *)&sysctl_vals[2]) | |
44 | #define SYSCTL_TWO ((void *)&sysctl_vals[3]) | |
45 | #define SYSCTL_FOUR ((void *)&sysctl_vals[4]) | |
46 | #define SYSCTL_ONE_HUNDRED ((void *)&sysctl_vals[5]) | |
47 | #define SYSCTL_TWO_HUNDRED ((void *)&sysctl_vals[6]) | |
48 | #define SYSCTL_ONE_THOUSAND ((void *)&sysctl_vals[7]) | |
49 | #define SYSCTL_THREE_THOUSAND ((void *)&sysctl_vals[8]) | |
50 | #define SYSCTL_INT_MAX ((void *)&sysctl_vals[9]) | |
eec4844f | 51 | |
54771613 LC |
52 | /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */ |
53 | #define SYSCTL_MAXOLDUID ((void *)&sysctl_vals[10]) | |
54 | ||
eec4844f MC |
55 | extern const int sysctl_vals[]; |
56 | ||
b1f2aff8 LC |
57 | #define SYSCTL_LONG_ZERO ((void *)&sysctl_long_vals[0]) |
58 | #define SYSCTL_LONG_ONE ((void *)&sysctl_long_vals[1]) | |
59 | #define SYSCTL_LONG_MAX ((void *)&sysctl_long_vals[2]) | |
60 | ||
61 | extern const unsigned long sysctl_long_vals[]; | |
62 | ||
32927393 CH |
63 | typedef int proc_handler(struct ctl_table *ctl, int write, void *buffer, |
64 | size_t *lenp, loff_t *ppos); | |
65 | ||
66 | int proc_dostring(struct ctl_table *, int, void *, size_t *, loff_t *); | |
a2071573 JH |
67 | int proc_dobool(struct ctl_table *table, int write, void *buffer, |
68 | size_t *lenp, loff_t *ppos); | |
32927393 CH |
69 | int proc_dointvec(struct ctl_table *, int, void *, size_t *, loff_t *); |
70 | int proc_douintvec(struct ctl_table *, int, void *, size_t *, loff_t *); | |
71 | int proc_dointvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *); | |
72 | int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer, | |
73 | size_t *lenp, loff_t *ppos); | |
cb944413 ED |
74 | int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer, |
75 | size_t *lenp, loff_t *ppos); | |
32927393 CH |
76 | int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *); |
77 | int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *, | |
78 | loff_t *); | |
79 | int proc_dointvec_ms_jiffies(struct ctl_table *, int, void *, size_t *, | |
80 | loff_t *); | |
81 | int proc_doulongvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *); | |
82 | int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, void *, | |
83 | size_t *, loff_t *); | |
84 | int proc_do_large_bitmap(struct ctl_table *, int, void *, size_t *, loff_t *); | |
85 | int proc_do_static_key(struct ctl_table *table, int write, void *buffer, | |
86 | size_t *lenp, loff_t *ppos); | |
1da177e4 | 87 | |
1da177e4 LT |
88 | /* |
89 | * Register a set of sysctl names by calling register_sysctl_table | |
2315ffa0 EB |
90 | * with an initialised array of struct ctl_table's. An entry with |
91 | * NULL procname terminates the table. table->de will be | |
d99f160a | 92 | * set up by the registration and need not be initialised in advance. |
1da177e4 LT |
93 | * |
94 | * sysctl names can be mirrored automatically under /proc/sys. The | |
95 | * procname supplied controls /proc naming. | |
96 | * | |
88db0aa2 | 97 | * The table's mode will be honoured for proc-fs access. |
1da177e4 LT |
98 | * |
99 | * Leaf nodes in the sysctl tree will be represented by a single file | |
100 | * under /proc; non-leaf nodes will be represented by directories. A | |
101 | * null procname disables /proc mirroring at this node. | |
d99f160a | 102 | * |
88db0aa2 | 103 | * The data and maxlen fields of the ctl_table |
1da177e4 LT |
104 | * struct enable minimal validation of the values being written to be |
105 | * performed, and the mode field allows minimal authentication. | |
106 | * | |
1da177e4 LT |
107 | * There must be a proc_handler routine for any terminal nodes |
108 | * mirrored under /proc/sys (non-terminals are handled by a built-in | |
109 | * directory handler). Several default handlers are available to | |
110 | * cover common cases. | |
111 | */ | |
112 | ||
f1ecf068 LDM |
113 | /* Support for userspace poll() to watch for changes */ |
114 | struct ctl_table_poll { | |
115 | atomic_t event; | |
116 | wait_queue_head_t wait; | |
117 | }; | |
118 | ||
119 | static inline void *proc_sys_poll_event(struct ctl_table_poll *poll) | |
120 | { | |
121 | return (void *)(unsigned long)atomic_read(&poll->event); | |
122 | } | |
123 | ||
f1ecf068 LDM |
124 | #define __CTL_TABLE_POLL_INITIALIZER(name) { \ |
125 | .event = ATOMIC_INIT(0), \ | |
126 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) } | |
127 | ||
128 | #define DEFINE_CTL_TABLE_POLL(name) \ | |
129 | struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name) | |
130 | ||
1da177e4 | 131 | /* A sysctl table is an array of struct ctl_table: */ |
d5ffb71b | 132 | struct ctl_table { |
1da177e4 LT |
133 | const char *procname; /* Text ID for /proc/sys, or zero */ |
134 | void *data; | |
135 | int maxlen; | |
36fcb589 | 136 | umode_t mode; |
f728019b | 137 | struct ctl_table *child; /* Deprecated */ |
1da177e4 | 138 | proc_handler *proc_handler; /* Callback for text formatting */ |
f1ecf068 | 139 | struct ctl_table_poll *poll; |
1da177e4 LT |
140 | void *extra1; |
141 | void *extra2; | |
3859a271 | 142 | } __randomize_layout; |
1da177e4 | 143 | |
ac13ac6f EB |
144 | struct ctl_node { |
145 | struct rb_node node; | |
146 | struct ctl_table_header *header; | |
147 | }; | |
148 | ||
1da177e4 | 149 | /* struct ctl_table_header is used to maintain dynamic lists of |
d8217f07 | 150 | struct ctl_table trees. */ |
d5ffb71b | 151 | struct ctl_table_header { |
dfef6dcd AV |
152 | union { |
153 | struct { | |
154 | struct ctl_table *ctl_table; | |
dfef6dcd AV |
155 | int used; |
156 | int count; | |
938aaa4f | 157 | int nreg; |
dfef6dcd AV |
158 | }; |
159 | struct rcu_head rcu; | |
160 | }; | |
330d57fb | 161 | struct completion *unregistering; |
23eb06de | 162 | struct ctl_table *ctl_table_arg; |
e51b6ba0 | 163 | struct ctl_table_root *root; |
73455092 | 164 | struct ctl_table_set *set; |
7ec66d06 | 165 | struct ctl_dir *parent; |
ac13ac6f | 166 | struct ctl_node *node; |
2fd1d2c4 | 167 | struct hlist_head inodes; /* head for proc_inode->sysctl_inodes */ |
7ec66d06 EB |
168 | }; |
169 | ||
170 | struct ctl_dir { | |
171 | /* Header must be at the start of ctl_dir */ | |
172 | struct ctl_table_header header; | |
ac13ac6f | 173 | struct rb_root root; |
1da177e4 LT |
174 | }; |
175 | ||
0ce8974d | 176 | struct ctl_table_set { |
0ce8974d | 177 | int (*is_seen)(struct ctl_table_set *); |
0e47c99d | 178 | struct ctl_dir dir; |
0ce8974d EB |
179 | }; |
180 | ||
181 | struct ctl_table_root { | |
0ce8974d | 182 | struct ctl_table_set default_set; |
13bcc6a2 | 183 | struct ctl_table_set *(*lookup)(struct ctl_table_root *root); |
e79c6a4f DT |
184 | void (*set_ownership)(struct ctl_table_header *head, |
185 | struct ctl_table *table, | |
186 | kuid_t *uid, kgid_t *gid); | |
73f7ef43 | 187 | int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); |
0ce8974d EB |
188 | }; |
189 | ||
29e796fd EB |
190 | /* struct ctl_path describes where in the hierarchy a table is added */ |
191 | struct ctl_path { | |
192 | const char *procname; | |
29e796fd EB |
193 | }; |
194 | ||
0ce8974d EB |
195 | #ifdef CONFIG_SYSCTL |
196 | ||
51cb8dfc LC |
197 | #define DECLARE_SYSCTL_BASE(_name, _table) \ |
198 | static struct ctl_table _name##_base_table[] = { \ | |
199 | { \ | |
200 | .procname = #_name, \ | |
201 | .mode = 0555, \ | |
202 | .child = _table, \ | |
203 | }, \ | |
204 | { }, \ | |
205 | } | |
206 | ||
207 | extern int __register_sysctl_base(struct ctl_table *base_table); | |
208 | ||
209 | #define register_sysctl_base(_name) __register_sysctl_base(_name##_base_table) | |
210 | ||
0ce8974d EB |
211 | void proc_sys_poll_notify(struct ctl_table_poll *poll); |
212 | ||
213 | extern void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 214 | struct ctl_table_root *root, |
0ce8974d | 215 | int (*is_seen)(struct ctl_table_set *)); |
97324cd8 | 216 | extern void retire_sysctl_set(struct ctl_table_set *set); |
0ce8974d | 217 | |
6e9d5164 | 218 | struct ctl_table_header *__register_sysctl_table( |
60a47a2e | 219 | struct ctl_table_set *set, |
6e9d5164 | 220 | const char *path, struct ctl_table *table); |
e51b6ba0 | 221 | struct ctl_table_header *__register_sysctl_paths( |
60a47a2e | 222 | struct ctl_table_set *set, |
e51b6ba0 | 223 | const struct ctl_path *path, struct ctl_table *table); |
fea478d4 | 224 | struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table); |
d8217f07 | 225 | struct ctl_table_header *register_sysctl_table(struct ctl_table * table); |
29e796fd EB |
226 | struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, |
227 | struct ctl_table *table); | |
0b4d4147 | 228 | |
1da177e4 LT |
229 | void unregister_sysctl_table(struct ctl_table_header * table); |
230 | ||
d8c0418a | 231 | extern int sysctl_init_bases(void); |
3ddd9a80 XN |
232 | extern void __register_sysctl_init(const char *path, struct ctl_table *table, |
233 | const char *table_name); | |
234 | #define register_sysctl_init(path, table) __register_sysctl_init(path, table, #table) | |
ee9efac4 LC |
235 | extern struct ctl_table_header *register_sysctl_mount_point(const char *path); |
236 | ||
3db978d4 | 237 | void do_sysctl_args(void); |
1998f193 LC |
238 | int do_proc_douintvec(struct ctl_table *table, int write, |
239 | void *buffer, size_t *lenp, loff_t *ppos, | |
240 | int (*conv)(unsigned long *lvalp, | |
241 | unsigned int *valp, | |
242 | int write, void *data), | |
243 | void *data); | |
f9bd6733 | 244 | |
2374c09b CH |
245 | extern int pwrsw_enabled; |
246 | extern int unaligned_enabled; | |
247 | extern int unaligned_dump_stack; | |
248 | extern int no_unaligned_warning; | |
249 | ||
f9bd6733 EB |
250 | extern struct ctl_table sysctl_mount_point[]; |
251 | ||
0ce8974d | 252 | #else /* CONFIG_SYSCTL */ |
51cb8dfc LC |
253 | |
254 | #define DECLARE_SYSCTL_BASE(_name, _table) | |
255 | ||
256 | static inline int __register_sysctl_base(struct ctl_table *base_table) | |
257 | { | |
258 | return 0; | |
259 | } | |
260 | ||
261 | #define register_sysctl_base(table) __register_sysctl_base(table) | |
262 | ||
0ce8974d EB |
263 | static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table) |
264 | { | |
265 | return NULL; | |
266 | } | |
267 | ||
ee9efac4 LC |
268 | static inline struct sysctl_header *register_sysctl_mount_point(const char *path) |
269 | { | |
270 | return NULL; | |
271 | } | |
272 | ||
0ce8974d EB |
273 | static inline struct ctl_table_header *register_sysctl_paths( |
274 | const struct ctl_path *path, struct ctl_table *table) | |
275 | { | |
276 | return NULL; | |
277 | } | |
278 | ||
e609a6b8 AB |
279 | static inline struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) |
280 | { | |
281 | return NULL; | |
282 | } | |
283 | ||
0ce8974d EB |
284 | static inline void unregister_sysctl_table(struct ctl_table_header * table) |
285 | { | |
286 | } | |
287 | ||
288 | static inline void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 289 | struct ctl_table_root *root, |
0ce8974d EB |
290 | int (*is_seen)(struct ctl_table_set *)) |
291 | { | |
292 | } | |
293 | ||
3db978d4 VB |
294 | static inline void do_sysctl_args(void) |
295 | { | |
296 | } | |
0ce8974d EB |
297 | #endif /* CONFIG_SYSCTL */ |
298 | ||
32927393 CH |
299 | int sysctl_max_threads(struct ctl_table *table, int write, void *buffer, |
300 | size_t *lenp, loff_t *ppos); | |
16db3d3f | 301 | |
1da177e4 | 302 | #endif /* _LINUX_SYSCTL_H */ |