summaryrefslogtreecommitdiffstats
path: root/include/linux/kmod.h
blob: dd99c329e1616ec76af1c9e8b2d11cee08434aea (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
#ifndef __LINUX_KMOD_H__
#define __LINUX_KMOD_H__

/*
 *	include/linux/kmod.h
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/gfp.h>
#include <linux/stddef.h>
#include <linux/errno.h>
#include <linux/compiler.h>
#include <linux/workqueue.h>
#include <linux/sysctl.h>

#define KMOD_PATH_LEN 256

#ifdef CONFIG_MODULES
extern char modprobe_path[]; /* for sysctl */
/* modprobe exit status on success, -ve on error.  Return value
 * usually useless though. */
extern __printf(2, 3)
int __request_module(bool wait, const char *name, ...);
#define request_module(mod...) __request_module(true, mod)
#define request_module_nowait(mod...) __request_module(false, mod)
#define try_then_request_module(x, mod...) \
	((x) ?: (__request_module(true, mod), (x)))
#else
static inline int request_module(const char *name, ...) { return -ENOSYS; }
static inline int request_module_nowait(const char *name, ...) { return -ENOSYS; }
#define try_then_request_module(x, mod...) (x)
#endif


struct cred;
struct file;

#define UMH_NO_WAIT	0	/* don't wait at all */
#define UMH_WAIT_EXEC	1	/* wait for the exec, but not the process */
#define UMH_WAIT_PROC	2	/* wait for the process to complete */
#define UMH_KILLABLE	4	/* wait for EXEC/PROC killable */

struct subprocess_info {
	struct work_struct work;
	struct completion *complete;
	char *path;
	char **argv;
	char **envp;
	int wait;
	int retval;
	int (*init)(struct subprocess_info *info, struct cred *new);
	void (*cleanup)(struct subprocess_info *info);
	void *data;
};

/* Allocate a subprocess_info structure */
struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
						  char **envp, gfp_t gfp_mask);

/* Set various pieces of state into the subprocess_info structure */
void call_usermodehelper_setfns(struct subprocess_info *info,
		    int (*init)(struct subprocess_info *info, struct cred *new),
		    void (*cleanup)(struct subprocess_info *info),
		    void *data);

/* Actually execute the sub-process */
int call_usermodehelper_exec(struct subprocess_info *info, int wait);

/* Free the subprocess_info. This is only needed if you're not going
   to call call_usermodehelper_exec */
void call_usermodehelper_freeinfo(struct subprocess_info *info);

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)
{
	struct subprocess_info *info;
	gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;

	info = call_usermodehelper_setup(path, argv, envp, gfp_mask);

	if (info == NULL)
		return -ENOMEM;

	call_usermodehelper_setfns(info, init, cleanup, data);

	return call_usermodehelper_exec(info, wait);
}

static inline int
call_usermodehelper(char *path, char **argv, char **envp, int wait)
{
	return call_usermodehelper_fns(path, argv, envp, wait,
				       NULL, NULL, NULL);
}

extern struct ctl_table usermodehelper_table[];

enum umh_disable_depth {
	UMH_ENABLED = 0,
	UMH_FREEZING,
	UMH_DISABLED,
};

extern void usermodehelper_init(void);

extern int __usermodehelper_disable(enum umh_disable_depth depth);
extern void __usermodehelper_set_disable_depth(enum umh_disable_depth depth);

static inline int usermodehelper_disable(void)
{
	return __usermodehelper_disable(UMH_DISABLED);
}

static inline void usermodehelper_enable(void)
{
	__usermodehelper_set_disable_depth(UMH_ENABLED);
}

extern int usermodehelper_read_trylock(void);
extern long usermodehelper_read_lock_wait(long timeout);
extern void usermodehelper_read_unlock(void);

#endif /* __LINUX_KMOD_H__ */