1 | /* |
2 | * proc sysctl test driver |
3 | * |
4 | * Copyright (C) 2017 Luis R. Rodriguez <mcgrof@kernel.org> |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify it |
7 | * under the terms of the GNU General Public License as published by the Free |
8 | * Software Foundation; either version 2 of the License, or at your option any |
9 | * later version; or, when distributed separately from the Linux kernel or |
10 | * when incorporated into other software packages, subject to the following |
11 | * license: |
12 | * |
13 | * This program is free software; you can redistribute it and/or modify it |
14 | * under the terms of copyleft-next (version 0.3.1 or later) as published |
15 | * at http://copyleft-next.org/. |
16 | */ |
17 | |
18 | /* |
19 | * This module provides an interface to the the proc sysctl interfaces. This |
20 | * driver requires CONFIG_PROC_SYSCTL. It will not normally be loaded by the |
21 | * system unless explicitly requested by name. You can also build this driver |
22 | * into your kernel. |
23 | */ |
24 | |
25 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
26 | |
27 | #include <linux/init.h> |
28 | #include <linux/list.h> |
29 | #include <linux/module.h> |
30 | #include <linux/printk.h> |
31 | #include <linux/fs.h> |
32 | #include <linux/miscdevice.h> |
33 | #include <linux/slab.h> |
34 | #include <linux/uaccess.h> |
35 | #include <linux/async.h> |
36 | #include <linux/delay.h> |
37 | #include <linux/vmalloc.h> |
38 | |
39 | static int i_zero; |
40 | static int i_one_hundred = 100; |
41 | |
42 | struct test_sysctl_data { |
43 | int int_0001; |
44 | int int_0002; |
45 | int int_0003[4]; |
46 | |
47 | unsigned int uint_0001; |
48 | |
49 | char string_0001[65]; |
50 | }; |
51 | |
52 | static struct test_sysctl_data test_data = { |
53 | .int_0001 = 60, |
54 | .int_0002 = 1, |
55 | |
56 | .int_0003[0] = 0, |
57 | .int_0003[1] = 1, |
58 | .int_0003[2] = 2, |
59 | .int_0003[3] = 3, |
60 | |
61 | .uint_0001 = 314, |
62 | |
63 | .string_0001 = "(none)" , |
64 | }; |
65 | |
66 | /* These are all under /proc/sys/debug/test_sysctl/ */ |
67 | static struct ctl_table test_table[] = { |
68 | { |
69 | .procname = "int_0001" , |
70 | .data = &test_data.int_0001, |
71 | .maxlen = sizeof(int), |
72 | .mode = 0644, |
73 | .proc_handler = proc_dointvec_minmax, |
74 | .extra1 = &i_zero, |
75 | .extra2 = &i_one_hundred, |
76 | }, |
77 | { |
78 | .procname = "int_0002" , |
79 | .data = &test_data.int_0002, |
80 | .maxlen = sizeof(int), |
81 | .mode = 0644, |
82 | .proc_handler = proc_dointvec, |
83 | }, |
84 | { |
85 | .procname = "int_0003" , |
86 | .data = &test_data.int_0003, |
87 | .maxlen = sizeof(test_data.int_0003), |
88 | .mode = 0644, |
89 | .proc_handler = proc_dointvec, |
90 | }, |
91 | { |
92 | .procname = "uint_0001" , |
93 | .data = &test_data.uint_0001, |
94 | .maxlen = sizeof(unsigned int), |
95 | .mode = 0644, |
96 | .proc_handler = proc_douintvec, |
97 | }, |
98 | { |
99 | .procname = "string_0001" , |
100 | .data = &test_data.string_0001, |
101 | .maxlen = sizeof(test_data.string_0001), |
102 | .mode = 0644, |
103 | .proc_handler = proc_dostring, |
104 | }, |
105 | { } |
106 | }; |
107 | |
108 | static struct ctl_table test_sysctl_table[] = { |
109 | { |
110 | .procname = "test_sysctl" , |
111 | .maxlen = 0, |
112 | .mode = 0555, |
113 | .child = test_table, |
114 | }, |
115 | { } |
116 | }; |
117 | |
118 | static struct ctl_table test_sysctl_root_table[] = { |
119 | { |
120 | .procname = "debug" , |
121 | .maxlen = 0, |
122 | .mode = 0555, |
123 | .child = test_sysctl_table, |
124 | }, |
125 | { } |
126 | }; |
127 | |
128 | static struct ctl_table_header *; |
129 | |
130 | static int __init test_sysctl_init(void) |
131 | { |
132 | test_sysctl_header = register_sysctl_table(test_sysctl_root_table); |
133 | if (!test_sysctl_header) |
134 | return -ENOMEM; |
135 | return 0; |
136 | } |
137 | late_initcall(test_sysctl_init); |
138 | |
139 | static void __exit test_sysctl_exit(void) |
140 | { |
141 | if (test_sysctl_header) |
142 | unregister_sysctl_table(test_sysctl_header); |
143 | } |
144 | |
145 | module_exit(test_sysctl_exit); |
146 | |
147 | MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>" ); |
148 | MODULE_LICENSE("GPL" ); |
149 | |