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(const char * name, ...) __attribute__ ((format (printf, 1, 2)));
  33 #define try_then_request_module(x, mod...) ((x) ?: (request_module(mod), (x)))
  34 #else
  35 static inline int request_module(const char * name, ...) { return -ENOSYS; }
  36 #define try_then_request_module(x, mod...) (x)
  37 #endif
  38
  39
  40 struct key;
  41 struct file;
  42 struct subprocess_info;
  43
  44 /* Allocate a subprocess_info structure */
  45 struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
  46                                                   char **envp, gfp_t gfp_mask);
  47
  48 /* Set various pieces of state into the subprocess_info structure */
  49 void call_usermodehelper_setkeys(struct subprocess_info *info,
  50                                  struct key *session_keyring);
  51 int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info,
  52                                   struct file **filp);
  53 void call_usermodehelper_setcleanup(struct subprocess_info *info,
  54                                     void (*cleanup)(char **argv, char **envp));
  55
  56 enum umh_wait {
  57         UMH_NO_WAIT = -1,       /* don't wait at all */
  58         UMH_WAIT_EXEC = 0,      /* wait for the exec, but not the process */
  59         UMH_WAIT_PROC = 1,      /* wait for the process to complete */
  60 };
  61
  62 /* Actually execute the sub-process */
  63 int call_usermodehelper_exec(struct subprocess_info *info, enum umh_wait wait);
  64
  65 /* Free the subprocess_info. This is only needed if you're not going
  66    to call call_usermodehelper_exec */
  67 void call_usermodehelper_freeinfo(struct subprocess_info *info);
  68
  69 static inline int
  70 call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait)
  71 {
  72         struct subprocess_info *info;
  73         gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
  74
  75         info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
  76         if (info == NULL)
  77                 return -ENOMEM;
  78         return call_usermodehelper_exec(info, wait);
  79 }
  80
  81 static inline int
  82 call_usermodehelper_keys(char *path, char **argv, char **envp,
  83                          struct key *session_keyring, enum umh_wait wait)
  84 {
  85         struct subprocess_info *info;
  86         gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
  87
  88         info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
  89         if (info == NULL)
  90                 return -ENOMEM;
  91
  92         call_usermodehelper_setkeys(info, session_keyring);
  93         return call_usermodehelper_exec(info, wait);
  94 }
  95
  96 extern void usermodehelper_init(void);
  97
  98 struct file;
  99 extern int call_usermodehelper_pipe(char *path, char *argv[], char *envp[],
 100                                     struct file **filp);
 101
 102 #endif /* __LINUX_KMOD_H__ */