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 *); |
e7d316a0 SAK |
46 | extern int proc_douintvec(struct ctl_table *, int, |
47 | void __user *, size_t *, loff_t *); | |
8d65af78 | 48 | extern int proc_dointvec_minmax(struct ctl_table *, int, |
1da177e4 | 49 | void __user *, size_t *, loff_t *); |
61d9b56a LR |
50 | extern int proc_douintvec_minmax(struct ctl_table *table, int write, |
51 | void __user *buffer, size_t *lenp, | |
52 | loff_t *ppos); | |
8d65af78 | 53 | extern int proc_dointvec_jiffies(struct ctl_table *, int, |
1da177e4 | 54 | void __user *, size_t *, loff_t *); |
8d65af78 | 55 | extern int proc_dointvec_userhz_jiffies(struct ctl_table *, int, |
1da177e4 | 56 | void __user *, size_t *, loff_t *); |
8d65af78 | 57 | extern int proc_dointvec_ms_jiffies(struct ctl_table *, int, |
1da177e4 | 58 | void __user *, size_t *, loff_t *); |
8d65af78 | 59 | extern int proc_doulongvec_minmax(struct ctl_table *, int, |
1da177e4 | 60 | void __user *, size_t *, loff_t *); |
d8217f07 | 61 | extern int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, |
8d65af78 | 62 | void __user *, size_t *, loff_t *); |
9f977fb7 OP |
63 | extern int proc_do_large_bitmap(struct ctl_table *, int, |
64 | void __user *, size_t *, loff_t *); | |
1da177e4 | 65 | |
1da177e4 LT |
66 | /* |
67 | * Register a set of sysctl names by calling register_sysctl_table | |
2315ffa0 EB |
68 | * with an initialised array of struct ctl_table's. An entry with |
69 | * NULL procname terminates the table. table->de will be | |
d99f160a | 70 | * set up by the registration and need not be initialised in advance. |
1da177e4 LT |
71 | * |
72 | * sysctl names can be mirrored automatically under /proc/sys. The | |
73 | * procname supplied controls /proc naming. | |
74 | * | |
75 | * The table's mode will be honoured both for sys_sysctl(2) and | |
76 | * proc-fs access. | |
77 | * | |
78 | * Leaf nodes in the sysctl tree will be represented by a single file | |
79 | * under /proc; non-leaf nodes will be represented by directories. A | |
80 | * null procname disables /proc mirroring at this node. | |
d99f160a | 81 | * |
1da177e4 LT |
82 | * sysctl(2) can automatically manage read and write requests through |
83 | * the sysctl table. The data and maxlen fields of the ctl_table | |
84 | * struct enable minimal validation of the values being written to be | |
85 | * performed, and the mode field allows minimal authentication. | |
86 | * | |
1da177e4 LT |
87 | * There must be a proc_handler routine for any terminal nodes |
88 | * mirrored under /proc/sys (non-terminals are handled by a built-in | |
89 | * directory handler). Several default handlers are available to | |
90 | * cover common cases. | |
91 | */ | |
92 | ||
f1ecf068 LDM |
93 | /* Support for userspace poll() to watch for changes */ |
94 | struct ctl_table_poll { | |
95 | atomic_t event; | |
96 | wait_queue_head_t wait; | |
97 | }; | |
98 | ||
99 | static inline void *proc_sys_poll_event(struct ctl_table_poll *poll) | |
100 | { | |
101 | return (void *)(unsigned long)atomic_read(&poll->event); | |
102 | } | |
103 | ||
f1ecf068 LDM |
104 | #define __CTL_TABLE_POLL_INITIALIZER(name) { \ |
105 | .event = ATOMIC_INIT(0), \ | |
106 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) } | |
107 | ||
108 | #define DEFINE_CTL_TABLE_POLL(name) \ | |
109 | struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name) | |
110 | ||
1da177e4 LT |
111 | /* A sysctl table is an array of struct ctl_table: */ |
112 | struct ctl_table | |
113 | { | |
1da177e4 LT |
114 | const char *procname; /* Text ID for /proc/sys, or zero */ |
115 | void *data; | |
116 | int maxlen; | |
36fcb589 | 117 | umode_t mode; |
f728019b | 118 | struct ctl_table *child; /* Deprecated */ |
1da177e4 | 119 | proc_handler *proc_handler; /* Callback for text formatting */ |
f1ecf068 | 120 | struct ctl_table_poll *poll; |
1da177e4 LT |
121 | void *extra1; |
122 | void *extra2; | |
3859a271 | 123 | } __randomize_layout; |
1da177e4 | 124 | |
ac13ac6f EB |
125 | struct ctl_node { |
126 | struct rb_node node; | |
127 | struct ctl_table_header *header; | |
128 | }; | |
129 | ||
1da177e4 | 130 | /* struct ctl_table_header is used to maintain dynamic lists of |
d8217f07 | 131 | struct ctl_table trees. */ |
1da177e4 LT |
132 | struct ctl_table_header |
133 | { | |
dfef6dcd AV |
134 | union { |
135 | struct { | |
136 | struct ctl_table *ctl_table; | |
dfef6dcd AV |
137 | int used; |
138 | int count; | |
938aaa4f | 139 | int nreg; |
dfef6dcd AV |
140 | }; |
141 | struct rcu_head rcu; | |
142 | }; | |
330d57fb | 143 | struct completion *unregistering; |
23eb06de | 144 | struct ctl_table *ctl_table_arg; |
e51b6ba0 | 145 | struct ctl_table_root *root; |
73455092 | 146 | struct ctl_table_set *set; |
7ec66d06 | 147 | struct ctl_dir *parent; |
ac13ac6f | 148 | struct ctl_node *node; |
2fd1d2c4 | 149 | struct hlist_head inodes; /* head for proc_inode->sysctl_inodes */ |
7ec66d06 EB |
150 | }; |
151 | ||
152 | struct ctl_dir { | |
153 | /* Header must be at the start of ctl_dir */ | |
154 | struct ctl_table_header header; | |
ac13ac6f | 155 | struct rb_root root; |
1da177e4 LT |
156 | }; |
157 | ||
0ce8974d | 158 | struct ctl_table_set { |
0ce8974d | 159 | int (*is_seen)(struct ctl_table_set *); |
0e47c99d | 160 | struct ctl_dir dir; |
0ce8974d EB |
161 | }; |
162 | ||
163 | struct ctl_table_root { | |
0ce8974d | 164 | struct ctl_table_set default_set; |
13bcc6a2 | 165 | struct ctl_table_set *(*lookup)(struct ctl_table_root *root); |
e79c6a4f DT |
166 | void (*set_ownership)(struct ctl_table_header *head, |
167 | struct ctl_table *table, | |
168 | kuid_t *uid, kgid_t *gid); | |
73f7ef43 | 169 | int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); |
0ce8974d EB |
170 | }; |
171 | ||
29e796fd EB |
172 | /* struct ctl_path describes where in the hierarchy a table is added */ |
173 | struct ctl_path { | |
174 | const char *procname; | |
29e796fd EB |
175 | }; |
176 | ||
0ce8974d EB |
177 | #ifdef CONFIG_SYSCTL |
178 | ||
179 | void proc_sys_poll_notify(struct ctl_table_poll *poll); | |
180 | ||
181 | extern void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 182 | struct ctl_table_root *root, |
0ce8974d | 183 | int (*is_seen)(struct ctl_table_set *)); |
97324cd8 | 184 | extern void retire_sysctl_set(struct ctl_table_set *set); |
0ce8974d | 185 | |
6e9d5164 | 186 | struct ctl_table_header *__register_sysctl_table( |
60a47a2e | 187 | struct ctl_table_set *set, |
6e9d5164 | 188 | const char *path, struct ctl_table *table); |
e51b6ba0 | 189 | struct ctl_table_header *__register_sysctl_paths( |
60a47a2e | 190 | struct ctl_table_set *set, |
e51b6ba0 | 191 | const struct ctl_path *path, struct ctl_table *table); |
fea478d4 | 192 | struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table); |
d8217f07 | 193 | struct ctl_table_header *register_sysctl_table(struct ctl_table * table); |
29e796fd EB |
194 | struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, |
195 | struct ctl_table *table); | |
0b4d4147 | 196 | |
1da177e4 LT |
197 | void unregister_sysctl_table(struct ctl_table_header * table); |
198 | ||
de4e83bd | 199 | extern int sysctl_init(void); |
f9bd6733 EB |
200 | |
201 | extern struct ctl_table sysctl_mount_point[]; | |
202 | ||
0ce8974d EB |
203 | #else /* CONFIG_SYSCTL */ |
204 | static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table) | |
205 | { | |
206 | return NULL; | |
207 | } | |
208 | ||
209 | static inline struct ctl_table_header *register_sysctl_paths( | |
210 | const struct ctl_path *path, struct ctl_table *table) | |
211 | { | |
212 | return NULL; | |
213 | } | |
214 | ||
215 | static inline void unregister_sysctl_table(struct ctl_table_header * table) | |
216 | { | |
217 | } | |
218 | ||
219 | static inline void setup_sysctl_set(struct ctl_table_set *p, | |
9eb47c26 | 220 | struct ctl_table_root *root, |
0ce8974d EB |
221 | int (*is_seen)(struct ctl_table_set *)) |
222 | { | |
223 | } | |
224 | ||
0ce8974d EB |
225 | #endif /* CONFIG_SYSCTL */ |
226 | ||
16db3d3f HS |
227 | int sysctl_max_threads(struct ctl_table *table, int write, |
228 | void __user *buffer, size_t *lenp, loff_t *ppos); | |
229 | ||
1da177e4 | 230 | #endif /* _LINUX_SYSCTL_H */ |