1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * sysctl.h: General linux system control interface |
4 | * |
5 | * Begun 24 March 1995, Stephen Tweedie |
6 | * |
7 | **************************************************************** |
8 | **************************************************************** |
9 | ** |
10 | ** WARNING: |
11 | ** The values in this file are exported to user space via |
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 |
15 | ** redefine an existing interface, use a new number for it. |
16 | ** The kernel will then return -ENOTDIR to any application using |
17 | ** the old binary interface. |
18 | ** |
19 | **************************************************************** |
20 | **************************************************************** |
21 | */ |
22 | #ifndef _LINUX_SYSCTL_H |
23 | #define _LINUX_SYSCTL_H |
24 | |
25 | #include <linux/list.h> |
26 | #include <linux/rcupdate.h> |
27 | #include <linux/wait.h> |
28 | #include <linux/rbtree.h> |
29 | #include <linux/uidgid.h> |
30 | #include <uapi/linux/sysctl.h> |
31 | |
32 | /* For the /proc/sys support */ |
33 | struct completion; |
34 | struct ctl_table; |
35 | struct nsproxy; |
36 | struct ctl_table_root; |
37 | struct ctl_table_header; |
38 | struct ctl_dir; |
39 | |
40 | /* Keep the same order as in fs/proc/proc_sysctl.c */ |
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]) |
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]) |
51 | |
52 | /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */ |
53 | #define SYSCTL_MAXOLDUID ((void *)&sysctl_vals[10]) |
54 | #define SYSCTL_NEG_ONE ((void *)&sysctl_vals[11]) |
55 | |
56 | extern const int sysctl_vals[]; |
57 | |
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 | |
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 *); |
68 | int proc_dobool(struct ctl_table *table, int write, void *buffer, |
69 | size_t *lenp, loff_t *ppos); |
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); |
75 | int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer, |
76 | size_t *lenp, loff_t *ppos); |
77 | int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *); |
78 | int proc_dointvec_ms_jiffies_minmax(struct ctl_table *table, int write, |
79 | void *buffer, size_t *lenp, loff_t *ppos); |
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); |
90 | |
91 | /* |
92 | * Register a set of sysctl names by calling register_sysctl |
93 | * with an initialised array of struct ctl_table's. An entry with |
94 | * NULL procname terminates the table. table->de will be |
95 | * set up by the registration and need not be initialised in advance. |
96 | * |
97 | * sysctl names can be mirrored automatically under /proc/sys. The |
98 | * procname supplied controls /proc naming. |
99 | * |
100 | * The table's mode will be honoured for proc-fs access. |
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. |
105 | * |
106 | * The data and maxlen fields of the ctl_table |
107 | * struct enable minimal validation of the values being written to be |
108 | * performed, and the mode field allows minimal authentication. |
109 | * |
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 | |
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(v: &poll->event); |
125 | } |
126 | |
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 | |
134 | /* A sysctl table is an array of struct ctl_table: */ |
135 | struct ctl_table { |
136 | const char *procname; /* Text ID for /proc/sys, or zero */ |
137 | void *data; |
138 | int maxlen; |
139 | umode_t mode; |
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; |
151 | proc_handler *proc_handler; /* Callback for text formatting */ |
152 | struct ctl_table_poll *poll; |
153 | void *; |
154 | void *; |
155 | } __randomize_layout; |
156 | |
157 | struct ctl_node { |
158 | struct rb_node node; |
159 | struct ctl_table_header *; |
160 | }; |
161 | |
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 | */ |
173 | struct { |
174 | union { |
175 | struct { |
176 | struct ctl_table *; |
177 | int ; |
178 | int ; |
179 | int ; |
180 | int ; |
181 | }; |
182 | struct rcu_head ; |
183 | }; |
184 | struct completion *; |
185 | struct ctl_table *; |
186 | struct ctl_table_root *; |
187 | struct ctl_table_set *; |
188 | struct ctl_dir *; |
189 | struct ctl_node *; |
190 | struct hlist_head ; /* head for proc_inode->sysctl_inodes */ |
191 | }; |
192 | |
193 | struct ctl_dir { |
194 | /* Header must be at the start of ctl_dir */ |
195 | struct ctl_table_header ; |
196 | struct rb_root root; |
197 | }; |
198 | |
199 | struct ctl_table_set { |
200 | int (*is_seen)(struct ctl_table_set *); |
201 | struct ctl_dir dir; |
202 | }; |
203 | |
204 | struct ctl_table_root { |
205 | struct ctl_table_set default_set; |
206 | struct ctl_table_set *(*lookup)(struct ctl_table_root *root); |
207 | void (*set_ownership)(struct ctl_table_header *head, |
208 | struct ctl_table *table, |
209 | kuid_t *uid, kgid_t *gid); |
210 | int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); |
211 | }; |
212 | |
213 | #define register_sysctl(path, table) \ |
214 | register_sysctl_sz(path, table, ARRAY_SIZE(table)) |
215 | |
216 | #ifdef CONFIG_SYSCTL |
217 | |
218 | void proc_sys_poll_notify(struct ctl_table_poll *poll); |
219 | |
220 | extern void setup_sysctl_set(struct ctl_table_set *p, |
221 | struct ctl_table_root *root, |
222 | int (*is_seen)(struct ctl_table_set *)); |
223 | extern void retire_sysctl_set(struct ctl_table_set *set); |
224 | |
225 | struct ctl_table_header *__register_sysctl_table( |
226 | struct ctl_table_set *set, |
227 | const char *path, struct ctl_table *table, size_t table_size); |
228 | struct ctl_table_header *register_sysctl_sz(const char *path, struct ctl_table *table, |
229 | size_t table_size); |
230 | void unregister_sysctl_table(struct ctl_table_header * table); |
231 | |
232 | extern int sysctl_init_bases(void); |
233 | extern void __register_sysctl_init(const char *path, struct ctl_table *table, |
234 | const char *table_name, size_t table_size); |
235 | #define register_sysctl_init(path, table) \ |
236 | __register_sysctl_init(path, table, #table, ARRAY_SIZE(table)) |
237 | extern struct ctl_table_header *register_sysctl_mount_point(const char *path); |
238 | |
239 | void do_sysctl_args(void); |
240 | bool sysctl_is_alias(char *param); |
241 | int do_proc_douintvec(struct ctl_table *table, int write, |
242 | void *buffer, size_t *lenp, loff_t *ppos, |
243 | int (*conv)(unsigned long *lvalp, |
244 | unsigned int *valp, |
245 | int write, void *data), |
246 | void *data); |
247 | |
248 | extern int pwrsw_enabled; |
249 | extern int unaligned_enabled; |
250 | extern int unaligned_dump_stack; |
251 | extern int no_unaligned_warning; |
252 | |
253 | #else /* CONFIG_SYSCTL */ |
254 | |
255 | static inline void register_sysctl_init(const char *path, struct ctl_table *table) |
256 | { |
257 | } |
258 | |
259 | static inline struct ctl_table_header *register_sysctl_mount_point(const char *path) |
260 | { |
261 | return NULL; |
262 | } |
263 | |
264 | static inline struct ctl_table_header *register_sysctl_sz(const char *path, |
265 | struct ctl_table *table, |
266 | size_t table_size) |
267 | { |
268 | return NULL; |
269 | } |
270 | |
271 | static inline void unregister_sysctl_table(struct ctl_table_header * table) |
272 | { |
273 | } |
274 | |
275 | static inline void setup_sysctl_set(struct ctl_table_set *p, |
276 | struct ctl_table_root *root, |
277 | int (*is_seen)(struct ctl_table_set *)) |
278 | { |
279 | } |
280 | |
281 | static inline void do_sysctl_args(void) |
282 | { |
283 | } |
284 | |
285 | static inline bool sysctl_is_alias(char *param) |
286 | { |
287 | return false; |
288 | } |
289 | #endif /* CONFIG_SYSCTL */ |
290 | |
291 | int sysctl_max_threads(struct ctl_table *table, int write, void *buffer, |
292 | size_t *lenp, loff_t *ppos); |
293 | |
294 | #endif /* _LINUX_SYSCTL_H */ |
295 | |