Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * sysctl.h: General linux system control interface | |
3 | * | |
4 | * Begun 24 March 1995, Stephen Tweedie | |
5 | * | |
6 | **************************************************************** | |
7 | **************************************************************** | |
8 | ** | |
7cc13edc | 9 | ** WARNING: |
1da177e4 | 10 | ** The values in this file are exported to user space via |
7cc13edc EB |
11 | ** the sysctl() binary interface. Do *NOT* change the |
12 | ** numbering of any existing values here, and do not change | |
13 | ** any numbers within any one set of values. If you have to | |
93aec204 | 14 | ** redefine an existing interface, use a new number for it. |
7cc13edc EB |
15 | ** The kernel will then return -ENOTDIR to any application using |
16 | ** the old binary interface. | |
17 | ** | |
1da177e4 LT |
18 | **************************************************************** |
19 | **************************************************************** | |
20 | */ | |
1da177e4 LT |
21 | #ifndef _LINUX_SYSCTL_H |
22 | #define _LINUX_SYSCTL_H | |
23 | ||
d4ed803c | 24 | #include <linux/list.h> |
684adca4 | 25 | #include <linux/rcupdate.h> |
f1ecf068 | 26 | #include <linux/wait.h> |
ac13ac6f | 27 | #include <linux/rbtree.h> |
e79c6a4f | 28 | #include <linux/uidgid.h> |
607ca46e | 29 | #include <uapi/linux/sysctl.h> |
1da177e4 | 30 | |
805b5d5e | 31 | /* For the /proc/sys support */ |
db3f6001 | 32 | struct completion; |
1ff007eb | 33 | struct ctl_table; |
e51b6ba0 | 34 | struct nsproxy; |
d7321cd6 | 35 | struct ctl_table_root; |
f7e6ced4 | 36 | struct ctl_table_header; |
7ec66d06 | 37 | struct ctl_dir; |
f7e6ced4 | 38 | |
8d65af78 | 39 | typedef int proc_handler (struct ctl_table *ctl, int write, |
1da177e4 LT |
40 | void __user *buffer, size_t *lenp, loff_t *ppos); |
41 | ||
8d65af78 | 42 | extern int proc_dostring(struct ctl_table *, int, |
1da177e4 | 43 | void __user *, size_t *, loff_t *); |
8d65af78 | 44 | extern int proc_dointvec(struct ctl_table *, int, |
1da177e4 | 45 | void __user *, size_t *, loff_t *); |
8d65af78 | 46 | extern int proc_dointvec_minmax(struct ctl_table *, int, |
1da177e4 | 47 | void __user *, size_t *, loff_t *); |
8d65af78 | 48 | extern int proc_dointvec_jiffies(struct ctl_table *, int, |
1da177e4 | 49 | void __user *, size_t *, loff_t *); |
8d65af78 | 50 | extern int proc_dointvec_userhz_jiffies(struct ctl_table *, int, |
1da177e4 | 51 | void __user *, size_t *, loff_t *); |
8d65af78 | 52 | extern int proc_dointvec_ms_jiffies(struct ctl_table *, int, |
1da177e4 | 53 | void __user *, size_t *, loff_t *); |
8d65af78 | 54 | extern int proc_doulongvec_minmax(struct ctl_table *, int, |
1da177e4 | 55 | void __user *, size_t *, loff_t *); |
d8217f07 | 56 | extern int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, |
8d65af78 | 57 | void __user *, size_t *, loff_t *); |
9f977fb7 OP |
58 | extern int proc_do_large_bitmap(struct ctl_table *, int, |
59 | void __user *, size_t *, loff_t *); | |
1da177e4 | 60 | |
1da177e4 LT |
61 | /* |
62 | * Register a set of sysctl names by calling register_sysctl_table | |
2315ffa0 EB |
63 | * with an initialised array of struct ctl_table's. An entry with |
64 | * NULL procname terminates the table. table->de will be | |
d99f160a | 65 | * set up by the registration and need not be initialised in advance. |
1da177e4 LT |
66 | * |
67 | * sysctl names can be mirrored automatically under /proc/sys. The | |
68 | * procname supplied controls /proc naming. | |
69 | * | |
70 | * The table's mode will be honoured both for sys_sysctl(2) and | |
71 | * proc-fs access. | |
72 | * | |
73 | * Leaf nodes in the sysctl tree will be represented by a single file | |
74 | * under /proc; non-leaf nodes will be represented by directories. A | |
75 | * null procname disables /proc mirroring at this node. | |
d99f160a | 76 | * |
1da177e4 LT |
77 | * sysctl(2) can automatically manage read and write requests through |
78 | * the sysctl table. The data and maxlen fields of the ctl_table | |
79 | * struct enable minimal validation of the values being written to be | |
80 | * performed, and the mode field allows minimal authentication. | |
81 | * | |
1da177e4 LT |
82 | * There must be a proc_handler routine for any terminal nodes |
83 | * mirrored under /proc/sys (non-terminals are handled by a built-in | |
84 | * directory handler). Several default handlers are available to | |
85 | * cover common cases. | |
86 | */ | |
87 | ||
f1ecf068 LDM |
88 | /* Support for userspace poll() to watch for changes */ |
89 | struct ctl_table_poll { | |
90 | atomic_t event; | |
91 | wait_queue_head_t wait; | |
92 | }; | |
93 | ||
94 | static inline void *proc_sys_poll_event(struct ctl_table_poll *poll) | |
95 | { | |
96 | return (void *)(unsigned long)atomic_read(&poll->event); | |
97 | } | |
98 | ||
f1ecf068 LDM |
99 | #define __CTL_TABLE_POLL_INITIALIZER(name) { \ |
100 | .event = ATOMIC_INIT(0), \ | |
101 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) } | |
102 | ||
103 | #define DEFINE_CTL_TABLE_POLL(name) \ | |
104 | struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name) | |
105 | ||
1da177e4 LT |
106 | /* A sysctl table is an array of struct ctl_table: */ |
107 | struct ctl_table | |
108 | { | |
1da177e4 LT |
109 | const char *procname; /* Text ID for /proc/sys, or zero */ |
110 | void *data; | |
111 | int maxlen; | |
36fcb589 | 112 | umode_t mode; |
f728019b | 113 | struct ctl_table *child; /* Deprecated */ |
1da177e4 | 114 | proc_handler *proc_handler; /* Callback for text formatting */ |
f1ecf068 | 115 | struct ctl_table_poll *poll; |
1da177e4 LT |
116 | void *extra1; |
117 | void *extra2; | |
118 | }; | |
119 | ||
ac13ac6f EB |
120 | struct ctl_node { |
121 | struct rb_node node; | |
122 | struct ctl_table_header *header; | |
123 | }; | |
124 | ||
1da177e4 | 125 | /* struct ctl_table_header is used to maintain dynamic lists of |
d8217f07 | 126 | struct ctl_table trees. */ |
1da177e4 LT |
127 | struct ctl_table_header |
128 | { | |
dfef6dcd AV |
129 | union { |
130 | struct { | |
131 | struct ctl_table *ctl_table; | |
dfef6dcd AV |
132 | int used; |
133 | int count; | |
938aaa4f | 134 | int nreg; |
dfef6dcd AV |
135 | }; |
136 | struct rcu_head rcu; | |
137 | }; | |
330d57fb | 138 | struct completion *unregistering; |
23eb06de | 139 | struct ctl_table *ctl_table_arg; |
e51b6ba0 | 140 | struct ctl_table_root *root; |
73455092 | 141 | struct ctl_table_set *set; |
7ec66d06 | 142 | struct ctl_dir *parent; |
ac13ac6f | 143 | struct ctl_node *node; |
7ec66d06 EB |
144 | }; |
145 | ||
146 | struct ctl_dir { | |
147 | /* Header must be at the start of ctl_dir */ | |
148 | struct ctl_table_header header; | |
ac13ac6f | 149 | struct rb_root root; |
1da177e4 LT |
150 | }; |
151 | ||
0ce8974d | 152 | struct ctl_table_set { |
0ce8974d | 153 | int (*is_seen)(struct ctl_table_set *); |
0e47c99d | 154 | struct ctl_dir dir; |
0ce8974d EB |
155 | }; |
156 | ||
157 | struct ctl_table_root { | |
0ce8974d EB |
158 | struct ctl_table_set default_set; |
159 | struct ctl_table_set *(*lookup)(struct ctl_table_root *root, | |
160 | struct nsproxy *namespaces); | |
e79c6a4f DT |
161 | void (*set_ownership)(struct ctl_table_header *head, |
162 | struct ctl_table *table, | |
163 | kuid_t *uid, kgid_t *gid); | |
73f7ef43 | 164 | int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); |
0ce8974d EB |
165 | }; |
166 | ||
29e796fd EB |
167 | /* struct ctl_path describes where in the hierarchy a table is added */ |
168 | struct ctl_path { | |
169 | const char *procname; | |
29e796fd EB |
170 | }; |
171 | ||
0ce8974d EB |
172 | #ifdef CONFIG_SYSCTL |
173 | ||
174 | void proc_sys_poll_notify(struct ctl_table_poll *poll); | |
175 | ||
176 | extern void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 177 | struct ctl_table_root *root, |
0ce8974d | 178 | int (*is_seen)(struct ctl_table_set *)); |
97324cd8 | 179 | extern void retire_sysctl_set(struct ctl_table_set *set); |
0ce8974d | 180 | |
e51b6ba0 | 181 | void register_sysctl_root(struct ctl_table_root *root); |
6e9d5164 | 182 | struct ctl_table_header *__register_sysctl_table( |
60a47a2e | 183 | struct ctl_table_set *set, |
6e9d5164 | 184 | const char *path, struct ctl_table *table); |
e51b6ba0 | 185 | struct ctl_table_header *__register_sysctl_paths( |
60a47a2e | 186 | struct ctl_table_set *set, |
e51b6ba0 | 187 | const struct ctl_path *path, struct ctl_table *table); |
fea478d4 | 188 | struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table); |
d8217f07 | 189 | struct ctl_table_header *register_sysctl_table(struct ctl_table * table); |
29e796fd EB |
190 | struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, |
191 | struct ctl_table *table); | |
0b4d4147 | 192 | |
1da177e4 LT |
193 | void unregister_sysctl_table(struct ctl_table_header * table); |
194 | ||
de4e83bd | 195 | extern int sysctl_init(void); |
f9bd6733 EB |
196 | |
197 | extern struct ctl_table sysctl_mount_point[]; | |
198 | ||
0ce8974d EB |
199 | #else /* CONFIG_SYSCTL */ |
200 | static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table) | |
201 | { | |
202 | return NULL; | |
203 | } | |
204 | ||
205 | static inline struct ctl_table_header *register_sysctl_paths( | |
206 | const struct ctl_path *path, struct ctl_table *table) | |
207 | { | |
208 | return NULL; | |
209 | } | |
210 | ||
211 | static inline void unregister_sysctl_table(struct ctl_table_header * table) | |
212 | { | |
213 | } | |
214 | ||
215 | static inline void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 216 | struct ctl_table_root *root, |
0ce8974d EB |
217 | int (*is_seen)(struct ctl_table_set *)) |
218 | { | |
219 | } | |
220 | ||
0ce8974d EB |
221 | #endif /* CONFIG_SYSCTL */ |
222 | ||
16db3d3f HS |
223 | int sysctl_max_threads(struct ctl_table *table, int write, |
224 | void __user *buffer, size_t *lenp, loff_t *ppos); | |
225 | ||
1da177e4 | 226 | #endif /* _LINUX_SYSCTL_H */ |