xref: /linux-6.15/include/linux/kmod.h (revision a115bc07)
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 
27 #define KMOD_PATH_LEN 256
28 
29 #ifdef CONFIG_MODULES
30 /* modprobe exit status on success, -ve on error.  Return value
31  * usually useless though. */
32 extern int __request_module(bool wait, const char *name, ...) \
33 	__attribute__((format(printf, 2, 3)));
34 #define request_module(mod...) __request_module(true, mod)
35 #define request_module_nowait(mod...) __request_module(false, mod)
36 #define try_then_request_module(x, mod...) \
37 	((x) ?: (__request_module(true, mod), (x)))
38 #else
39 static inline int request_module(const char *name, ...) { return -ENOSYS; }
40 static inline int request_module_nowait(const char *name, ...) { return -ENOSYS; }
41 #define try_then_request_module(x, mod...) (x)
42 #endif
43 
44 
45 struct key;
46 struct file;
47 struct subprocess_info;
48 
49 /* Allocate a subprocess_info structure */
50 struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
51 						  char **envp, gfp_t gfp_mask);
52 
53 /* Set various pieces of state into the subprocess_info structure */
54 void call_usermodehelper_setkeys(struct subprocess_info *info,
55 				 struct key *session_keyring);
56 int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info,
57 				  struct file **filp);
58 void call_usermodehelper_setcleanup(struct subprocess_info *info,
59 				    void (*cleanup)(char **argv, char **envp));
60 
61 enum umh_wait {
62 	UMH_NO_WAIT = -1,	/* don't wait at all */
63 	UMH_WAIT_EXEC = 0,	/* wait for the exec, but not the process */
64 	UMH_WAIT_PROC = 1,	/* wait for the process to complete */
65 };
66 
67 /* Actually execute the sub-process */
68 int call_usermodehelper_exec(struct subprocess_info *info, enum umh_wait wait);
69 
70 /* Free the subprocess_info. This is only needed if you're not going
71    to call call_usermodehelper_exec */
72 void call_usermodehelper_freeinfo(struct subprocess_info *info);
73 
74 static inline int
75 call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait)
76 {
77 	struct subprocess_info *info;
78 	gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
79 
80 	info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
81 	if (info == NULL)
82 		return -ENOMEM;
83 	return call_usermodehelper_exec(info, wait);
84 }
85 
86 static inline int
87 call_usermodehelper_keys(char *path, char **argv, char **envp,
88 			 struct key *session_keyring, enum umh_wait wait)
89 {
90 	struct subprocess_info *info;
91 	gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
92 
93 	info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
94 	if (info == NULL)
95 		return -ENOMEM;
96 
97 	call_usermodehelper_setkeys(info, session_keyring);
98 	return call_usermodehelper_exec(info, wait);
99 }
100 
101 extern void usermodehelper_init(void);
102 
103 struct file;
104 extern int call_usermodehelper_pipe(char *path, char *argv[], char *envp[],
105 				    struct file **filp);
106 
107 extern int usermodehelper_disable(void);
108 extern void usermodehelper_enable(void);
109 
110 #endif /* __LINUX_KMOD_H__ */
111