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
  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__ */