xref: /linux-6.15/include/linux/kmod.h (revision 4dc7ccf7)
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 extern char modprobe_path[]; /* for sysctl */
31 /* modprobe exit status on success, -ve on error.  Return value
32  * usually useless though. */
33 extern int __request_module(bool wait, const char *name, ...) \
34 	__attribute__((format(printf, 2, 3)));
35 #define request_module(mod...) __request_module(true, mod)
36 #define request_module_nowait(mod...) __request_module(false, mod)
37 #define try_then_request_module(x, mod...) \
38 	((x) ?: (__request_module(true, mod), (x)))
39 #else
40 static inline int request_module(const char *name, ...) { return -ENOSYS; }
41 static inline int request_module_nowait(const char *name, ...) { return -ENOSYS; }
42 #define try_then_request_module(x, mod...) (x)
43 #endif
44 
45 
46 struct key;
47 struct file;
48 struct subprocess_info;
49 
50 /* Allocate a subprocess_info structure */
51 struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
52 						  char **envp, gfp_t gfp_mask);
53 
54 /* Set various pieces of state into the subprocess_info structure */
55 void call_usermodehelper_setkeys(struct subprocess_info *info,
56 				 struct key *session_keyring);
57 int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info,
58 				  struct file **filp);
59 void call_usermodehelper_setcleanup(struct subprocess_info *info,
60 				    void (*cleanup)(char **argv, char **envp));
61 
62 enum umh_wait {
63 	UMH_NO_WAIT = -1,	/* don't wait at all */
64 	UMH_WAIT_EXEC = 0,	/* wait for the exec, but not the process */
65 	UMH_WAIT_PROC = 1,	/* wait for the process to complete */
66 };
67 
68 /* Actually execute the sub-process */
69 int call_usermodehelper_exec(struct subprocess_info *info, enum umh_wait wait);
70 
71 /* Free the subprocess_info. This is only needed if you're not going
72    to call call_usermodehelper_exec */
73 void call_usermodehelper_freeinfo(struct subprocess_info *info);
74 
75 static inline int
76 call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait)
77 {
78 	struct subprocess_info *info;
79 	gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
80 
81 	info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
82 	if (info == NULL)
83 		return -ENOMEM;
84 	return call_usermodehelper_exec(info, wait);
85 }
86 
87 static inline int
88 call_usermodehelper_keys(char *path, char **argv, char **envp,
89 			 struct key *session_keyring, enum umh_wait wait)
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 	if (info == NULL)
96 		return -ENOMEM;
97 
98 	call_usermodehelper_setkeys(info, session_keyring);
99 	return call_usermodehelper_exec(info, wait);
100 }
101 
102 extern void usermodehelper_init(void);
103 
104 struct file;
105 extern int call_usermodehelper_pipe(char *path, char *argv[], char *envp[],
106 				    struct file **filp);
107 
108 extern int usermodehelper_disable(void);
109 extern void usermodehelper_enable(void);
110 
111 #endif /* __LINUX_KMOD_H__ */
112