include/linux/kmod.h

   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
  28 #define KMOD_PATH_LEN 256
  29
  30 #ifdef CONFIG_MODULES
  31 extern char modprobe_path[]; /* for sysctl */
  32 /* modprobe exit status on success, -ve on error.  Return value
  33  * usually useless though. */
  34 extern int __request_module(bool wait, const char *name, ...) \
  35         __attribute__((format(printf, 2, 3)));
  36 #define request_module(mod...) __request_module(true, mod)
  37 #define request_module_nowait(mod...) __request_module(false, mod)
  38 #define try_then_request_module(x, mod...) \
  39         ((x) ?: (__request_module(true, mod), (x)))
  40 #else
  41 static inline int request_module(const char *name, ...) { return -ENOSYS; }
  42 static inline int request_module_nowait(const char *name, ...) { return -ENOSYS; }
  43 #define try_then_request_module(x, mod...) (x)
  44 #endif
  45
  46
  47 struct key;
  48 struct file;
  49
  50 enum umh_wait {
  51         UMH_NO_WAIT = -1,       /* don't wait at all */
  52         UMH_WAIT_EXEC = 0,      /* wait for the exec, but not the process */
  53         UMH_WAIT_PROC = 1,      /* wait for the process to complete */
  54 };
  55
  56 struct subprocess_info {
  57         struct work_struct work;
  58         struct completion *complete;
  59         char *path;
  60         char **argv;
  61         char **envp;
  62         enum umh_wait wait;
  63         int retval;
  64         int (*init)(struct subprocess_info *info);
  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),
  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, enum umh_wait 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
  87 call_usermodehelper_fns(char *path, char **argv, char **envp,
  88                         enum umh_wait wait,
  89                         int (*init)(struct subprocess_info *info),
  90                         void (*cleanup)(struct subprocess_info *), void *data)
  91 {
  92         struct subprocess_info *info;
  93         gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
  94
  95         info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
  96
  97         if (info == NULL)
  98                 return -ENOMEM;
  99
 100         call_usermodehelper_setfns(info, init, cleanup, data);
 101
 102         return call_usermodehelper_exec(info, wait);
 103 }
 104
 105 static inline int
 106 call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait)
 107 {
 108         return call_usermodehelper_fns(path, argv, envp, wait,
 109                                        NULL, NULL, NULL);
 110 }
 111
 112 extern void usermodehelper_init(void);
 113
 114 extern int usermodehelper_disable(void);
 115 extern void usermodehelper_enable(void);
 116
 117 #endif /* __LINUX_KMOD_H__ */