1 #ifndef __LINUX_KMOD_H__
2 #define __LINUX_KMOD_H__
3
4 /*
5 * include/linux/kmod.h
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22 #include <linux/gfp.h>
23 #include <linux/stddef.h>
24 #include <linux/errno.h>
25 #include <linux/compiler.h>
26 #include <linux/workqueue.h>
27 #include <linux/sysctl.h>
28
29 #define KMOD_PATH_LEN 256
30
31 #ifdef CONFIG_MODULES
32 extern char modprobe_path[]; /* for sysctl */
33 /* modprobe exit status on success, -ve on error. Return value
34 * usually useless though. */
35 extern __printf(2, 3)
36 int __request_module(bool wait, const char *name, ...);
37 #define request_module(mod...) __request_module(true, mod)
38 #define request_module_nowait(mod...) __request_module(false, mod)
39 #define try_then_request_module(x, mod...) \
40 ((x) ?: (__request_module(true, mod), (x)))
41 #else
request_module(const char * name,...)42 static inline int request_module(const char *name, ...) { return -ENOSYS; }
request_module_nowait(const char * name,...)43 static inline int request_module_nowait(const char *name, ...) { return -ENOSYS; }
44 #define try_then_request_module(x, mod...) (x)
45 #endif
46
47
48 struct cred;
49 struct file;
50
51 #define UMH_NO_WAIT 0 /* don't wait at all */
52 #define UMH_WAIT_EXEC 1 /* wait for the exec, but not the process */
53 #define UMH_WAIT_PROC 2 /* wait for the process to complete */
54 #define UMH_KILLABLE 4 /* wait for EXEC/PROC killable */
55
56 struct subprocess_info {
57 struct work_struct work;
58 struct completion *complete;
59 char *path;
60 char **argv;
61 char **envp;
62 int wait;
63 int retval;
64 int (*init)(struct subprocess_info *info, struct cred *new);
65 void (*cleanup)(struct subprocess_info *info);
66 void *data;
67 };
68
69 /* Allocate a subprocess_info structure */
70 struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
71 char **envp, gfp_t gfp_mask);
72
73 /* Set various pieces of state into the subprocess_info structure */
74 void call_usermodehelper_setfns(struct subprocess_info *info,
75 int (*init)(struct subprocess_info *info, struct cred *new),
76 void (*cleanup)(struct subprocess_info *info),
77 void *data);
78
79 /* Actually execute the sub-process */
80 int call_usermodehelper_exec(struct subprocess_info *info, int wait);
81
82 /* Free the subprocess_info. This is only needed if you're not going
83 to call call_usermodehelper_exec */
84 void call_usermodehelper_freeinfo(struct subprocess_info *info);
85
86 static inline int
call_usermodehelper_fns(char * path,char ** argv,char ** envp,int wait,int (* init)(struct subprocess_info * info,struct cred * new),void (* cleanup)(struct subprocess_info *),void * data)87 call_usermodehelper_fns(char *path, char **argv, char **envp, int wait,
88 int (*init)(struct subprocess_info *info, struct cred *new),
89 void (*cleanup)(struct subprocess_info *), void *data)
90 {
91 struct subprocess_info *info;
92 gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
93
94 info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
95
96 if (info == NULL)
97 return -ENOMEM;
98
99 call_usermodehelper_setfns(info, init, cleanup, data);
100
101 return call_usermodehelper_exec(info, wait);
102 }
103
104 static inline int
call_usermodehelper(char * path,char ** argv,char ** envp,int wait)105 call_usermodehelper(char *path, char **argv, char **envp, int wait)
106 {
107 return call_usermodehelper_fns(path, argv, envp, wait,
108 NULL, NULL, NULL);
109 }
110
111 extern struct ctl_table usermodehelper_table[];
112
113 enum umh_disable_depth {
114 UMH_ENABLED = 0,
115 UMH_FREEZING,
116 UMH_DISABLED,
117 };
118
119 extern void usermodehelper_init(void);
120
121 extern int __usermodehelper_disable(enum umh_disable_depth depth);
122 extern void __usermodehelper_set_disable_depth(enum umh_disable_depth depth);
123
usermodehelper_disable(void)124 static inline int usermodehelper_disable(void)
125 {
126 return __usermodehelper_disable(UMH_DISABLED);
127 }
128
usermodehelper_enable(void)129 static inline void usermodehelper_enable(void)
130 {
131 __usermodehelper_set_disable_depth(UMH_ENABLED);
132 }
133
134 extern int usermodehelper_read_trylock(void);
135 extern long usermodehelper_read_lock_wait(long timeout);
136 extern void usermodehelper_read_unlock(void);
137
138 #endif /* __LINUX_KMOD_H__ */
139