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 */ |
4c7f24f8 TZ |
41 | #define SYSCTL_ZERO ((void *)&sysctl_vals[0]) |
42 | #define SYSCTL_ONE ((void *)&sysctl_vals[1]) | |
43 | #define SYSCTL_TWO ((void *)&sysctl_vals[2]) | |
44 | #define SYSCTL_THREE ((void *)&sysctl_vals[3]) | |
78e36f3b XN |
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]) | |
4c7f24f8 | 54 | #define SYSCTL_NEG_ONE ((void *)&sysctl_vals[11]) |
54771613 | 55 | |
eec4844f MC |
56 | extern const int sysctl_vals[]; |
57 | ||
b1f2aff8 LC |
58 | #define SYSCTL_LONG_ZERO ((void *)&sysctl_long_vals[0]) |
59 | #define SYSCTL_LONG_ONE ((void *)&sysctl_long_vals[1]) | |
60 | #define SYSCTL_LONG_MAX ((void *)&sysctl_long_vals[2]) | |
61 | ||
62 | extern const unsigned long sysctl_long_vals[]; | |
63 | ||
32927393 CH |
64 | typedef int proc_handler(struct ctl_table *ctl, int write, void *buffer, |
65 | size_t *lenp, loff_t *ppos); | |
66 | ||
67 | int proc_dostring(struct ctl_table *, int, void *, size_t *, loff_t *); | |
a2071573 JH |
68 | int proc_dobool(struct ctl_table *table, int write, void *buffer, |
69 | size_t *lenp, loff_t *ppos); | |
32927393 CH |
70 | int proc_dointvec(struct ctl_table *, int, void *, size_t *, loff_t *); |
71 | int proc_douintvec(struct ctl_table *, int, void *, size_t *, loff_t *); | |
72 | int proc_dointvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *); | |
73 | int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer, | |
74 | size_t *lenp, loff_t *ppos); | |
cb944413 ED |
75 | int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer, |
76 | size_t *lenp, loff_t *ppos); | |
32927393 | 77 | int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *); |
c381d02b YW |
78 | int proc_dointvec_ms_jiffies_minmax(struct ctl_table *table, int write, |
79 | void *buffer, size_t *lenp, loff_t *ppos); | |
32927393 CH |
80 | int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *, |
81 | loff_t *); | |
82 | int proc_dointvec_ms_jiffies(struct ctl_table *, int, void *, size_t *, | |
83 | loff_t *); | |
84 | int proc_doulongvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *); | |
85 | int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, void *, | |
86 | size_t *, loff_t *); | |
87 | int proc_do_large_bitmap(struct ctl_table *, int, void *, size_t *, loff_t *); | |
88 | int proc_do_static_key(struct ctl_table *table, int write, void *buffer, | |
89 | size_t *lenp, loff_t *ppos); | |
1da177e4 | 90 | |
1da177e4 | 91 | /* |
19c4e618 | 92 | * Register a set of sysctl names by calling register_sysctl |
2315ffa0 EB |
93 | * with an initialised array of struct ctl_table's. An entry with |
94 | * NULL procname terminates the table. table->de will be | |
d99f160a | 95 | * set up by the registration and need not be initialised in advance. |
1da177e4 LT |
96 | * |
97 | * sysctl names can be mirrored automatically under /proc/sys. The | |
98 | * procname supplied controls /proc naming. | |
99 | * | |
88db0aa2 | 100 | * The table's mode will be honoured for proc-fs access. |
1da177e4 LT |
101 | * |
102 | * Leaf nodes in the sysctl tree will be represented by a single file | |
103 | * under /proc; non-leaf nodes will be represented by directories. A | |
104 | * null procname disables /proc mirroring at this node. | |
d99f160a | 105 | * |
88db0aa2 | 106 | * The data and maxlen fields of the ctl_table |
1da177e4 LT |
107 | * struct enable minimal validation of the values being written to be |
108 | * performed, and the mode field allows minimal authentication. | |
109 | * | |
1da177e4 LT |
110 | * There must be a proc_handler routine for any terminal nodes |
111 | * mirrored under /proc/sys (non-terminals are handled by a built-in | |
112 | * directory handler). Several default handlers are available to | |
113 | * cover common cases. | |
114 | */ | |
115 | ||
f1ecf068 LDM |
116 | /* Support for userspace poll() to watch for changes */ |
117 | struct ctl_table_poll { | |
118 | atomic_t event; | |
119 | wait_queue_head_t wait; | |
120 | }; | |
121 | ||
122 | static inline void *proc_sys_poll_event(struct ctl_table_poll *poll) | |
123 | { | |
124 | return (void *)(unsigned long)atomic_read(&poll->event); | |
125 | } | |
126 | ||
f1ecf068 LDM |
127 | #define __CTL_TABLE_POLL_INITIALIZER(name) { \ |
128 | .event = ATOMIC_INIT(0), \ | |
129 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) } | |
130 | ||
131 | #define DEFINE_CTL_TABLE_POLL(name) \ | |
132 | struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name) | |
133 | ||
1da177e4 | 134 | /* A sysctl table is an array of struct ctl_table: */ |
d5ffb71b | 135 | struct ctl_table { |
1da177e4 LT |
136 | const char *procname; /* Text ID for /proc/sys, or zero */ |
137 | void *data; | |
138 | int maxlen; | |
36fcb589 | 139 | umode_t mode; |
2f2665c1 JG |
140 | /** |
141 | * enum type - Enumeration to differentiate between ctl target types | |
142 | * @SYSCTL_TABLE_TYPE_DEFAULT: ctl target with no special considerations | |
143 | * @SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY: Used to identify a permanently | |
144 | * empty directory target to serve | |
145 | * as mount point. | |
146 | */ | |
147 | enum { | |
148 | SYSCTL_TABLE_TYPE_DEFAULT, | |
149 | SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY | |
150 | } type; | |
1da177e4 | 151 | proc_handler *proc_handler; /* Callback for text formatting */ |
f1ecf068 | 152 | struct ctl_table_poll *poll; |
1da177e4 LT |
153 | void *extra1; |
154 | void *extra2; | |
3859a271 | 155 | } __randomize_layout; |
1da177e4 | 156 | |
ac13ac6f EB |
157 | struct ctl_node { |
158 | struct rb_node node; | |
159 | struct ctl_table_header *header; | |
160 | }; | |
161 | ||
1e887723 JG |
162 | /** |
163 | * struct ctl_table_header - maintains dynamic lists of struct ctl_table trees | |
164 | * @ctl_table: pointer to the first element in ctl_table array | |
165 | * @ctl_table_size: number of elements pointed by @ctl_table | |
166 | * @used: The entry will never be touched when equal to 0. | |
167 | * @count: Upped every time something is added to @inodes and downed every time | |
168 | * something is removed from inodes | |
169 | * @nreg: When nreg drops to 0 the ctl_table_header will be unregistered. | |
170 | * @rcu: Delays the freeing of the inode. Introduced with "unfuck proc_sysctl ->d_compare()" | |
171 | * | |
172 | */ | |
d5ffb71b | 173 | struct ctl_table_header { |
dfef6dcd AV |
174 | union { |
175 | struct { | |
176 | struct ctl_table *ctl_table; | |
1e887723 | 177 | int ctl_table_size; |
dfef6dcd AV |
178 | int used; |
179 | int count; | |
938aaa4f | 180 | int nreg; |
dfef6dcd AV |
181 | }; |
182 | struct rcu_head rcu; | |
183 | }; | |
330d57fb | 184 | struct completion *unregistering; |
23eb06de | 185 | struct ctl_table *ctl_table_arg; |
e51b6ba0 | 186 | struct ctl_table_root *root; |
73455092 | 187 | struct ctl_table_set *set; |
7ec66d06 | 188 | struct ctl_dir *parent; |
ac13ac6f | 189 | struct ctl_node *node; |
2fd1d2c4 | 190 | struct hlist_head inodes; /* head for proc_inode->sysctl_inodes */ |
7ec66d06 EB |
191 | }; |
192 | ||
193 | struct ctl_dir { | |
194 | /* Header must be at the start of ctl_dir */ | |
195 | struct ctl_table_header header; | |
ac13ac6f | 196 | struct rb_root root; |
1da177e4 LT |
197 | }; |
198 | ||
0ce8974d | 199 | struct ctl_table_set { |
0ce8974d | 200 | int (*is_seen)(struct ctl_table_set *); |
0e47c99d | 201 | struct ctl_dir dir; |
0ce8974d EB |
202 | }; |
203 | ||
204 | struct ctl_table_root { | |
0ce8974d | 205 | struct ctl_table_set default_set; |
13bcc6a2 | 206 | struct ctl_table_set *(*lookup)(struct ctl_table_root *root); |
e79c6a4f DT |
207 | void (*set_ownership)(struct ctl_table_header *head, |
208 | struct ctl_table *table, | |
209 | kuid_t *uid, kgid_t *gid); | |
73f7ef43 | 210 | int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); |
0ce8974d EB |
211 | }; |
212 | ||
29e796fd EB |
213 | /* struct ctl_path describes where in the hierarchy a table is added */ |
214 | struct ctl_path { | |
215 | const char *procname; | |
29e796fd EB |
216 | }; |
217 | ||
9edbfe92 JG |
218 | #define register_sysctl(path, table) \ |
219 | register_sysctl_sz(path, table, ARRAY_SIZE(table)) | |
220 | ||
0ce8974d EB |
221 | #ifdef CONFIG_SYSCTL |
222 | ||
223 | void proc_sys_poll_notify(struct ctl_table_poll *poll); | |
224 | ||
225 | extern void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 226 | struct ctl_table_root *root, |
0ce8974d | 227 | int (*is_seen)(struct ctl_table_set *)); |
97324cd8 | 228 | extern void retire_sysctl_set(struct ctl_table_set *set); |
0ce8974d | 229 | |
6e9d5164 | 230 | struct ctl_table_header *__register_sysctl_table( |
60a47a2e | 231 | struct ctl_table_set *set, |
bff97cf1 | 232 | const char *path, struct ctl_table *table, size_t table_size); |
9edbfe92 JG |
233 | struct ctl_table_header *register_sysctl_sz(const char *path, struct ctl_table *table, |
234 | size_t table_size); | |
1da177e4 LT |
235 | void unregister_sysctl_table(struct ctl_table_header * table); |
236 | ||
d8c0418a | 237 | extern int sysctl_init_bases(void); |
3ddd9a80 XN |
238 | extern void __register_sysctl_init(const char *path, struct ctl_table *table, |
239 | const char *table_name); | |
240 | #define register_sysctl_init(path, table) __register_sysctl_init(path, table, #table) | |
ee9efac4 LC |
241 | extern struct ctl_table_header *register_sysctl_mount_point(const char *path); |
242 | ||
3db978d4 | 243 | void do_sysctl_args(void); |
1998f193 LC |
244 | int do_proc_douintvec(struct ctl_table *table, int write, |
245 | void *buffer, size_t *lenp, loff_t *ppos, | |
246 | int (*conv)(unsigned long *lvalp, | |
247 | unsigned int *valp, | |
248 | int write, void *data), | |
249 | void *data); | |
f9bd6733 | 250 | |
2374c09b CH |
251 | extern int pwrsw_enabled; |
252 | extern int unaligned_enabled; | |
253 | extern int unaligned_dump_stack; | |
254 | extern int no_unaligned_warning; | |
255 | ||
2f2665c1 | 256 | #define SYSCTL_PERM_EMPTY_DIR (1 << 0) |
f9bd6733 | 257 | |
0ce8974d | 258 | #else /* CONFIG_SYSCTL */ |
51cb8dfc | 259 | |
6213834c MS |
260 | static inline void register_sysctl_init(const char *path, struct ctl_table *table) |
261 | { | |
262 | } | |
263 | ||
6cb91741 | 264 | static inline struct ctl_table_header *register_sysctl_mount_point(const char *path) |
ee9efac4 LC |
265 | { |
266 | return NULL; | |
267 | } | |
268 | ||
9edbfe92 JG |
269 | static inline struct ctl_table_header *register_sysctl_sz(const char *path, |
270 | struct ctl_table *table, | |
271 | size_t table_size) | |
e609a6b8 AB |
272 | { |
273 | return NULL; | |
274 | } | |
275 | ||
0ce8974d EB |
276 | static inline void unregister_sysctl_table(struct ctl_table_header * table) |
277 | { | |
278 | } | |
279 | ||
280 | static inline void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 281 | struct ctl_table_root *root, |
0ce8974d EB |
282 | int (*is_seen)(struct ctl_table_set *)) |
283 | { | |
284 | } | |
285 | ||
3db978d4 VB |
286 | static inline void do_sysctl_args(void) |
287 | { | |
288 | } | |
0ce8974d EB |
289 | #endif /* CONFIG_SYSCTL */ |
290 | ||
32927393 CH |
291 | int sysctl_max_threads(struct ctl_table *table, int write, void *buffer, |
292 | size_t *lenp, loff_t *ppos); | |
16db3d3f | 293 | |
1da177e4 | 294 | #endif /* _LINUX_SYSCTL_H */ |