LXR linux/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#include <linux/sysctl.h>
  28
  29#define KMOD_PATH_LEN 256
  30
  31#ifdef CONFIG_MODULES
  32extern char modprobe_path[]; /* for sysctl */
  33/* modprobe exit status on success, -ve on error.  Return value
  34 * usually useless though. */
  35extern __printf(2, 3)
  36int __request_module(bool wait, const char *name, ...);
  37#define request_module(mod...) __request_module(true, mod)
  38#define request_module_nowait(mod...) __request_module(false, mod)
  39#define try_then_request_module(x, mod...) \
  40        ((x) ?: (__request_module(true, mod), (x)))
  41#else
  42static inline int request_module(const char *name, ...) { return -ENOSYS; }
  43static inline int request_module_nowait(const char *name, ...) { return -ENOSYS; }
  44#define try_then_request_module(x, mod...) (x)
  45#endif
  46
  47
  48struct cred;
  49struct file;
  50
  51enum umh_wait {
  52        UMH_NO_WAIT = -1,       /* don't wait at all */
  53        UMH_WAIT_EXEC = 0,      /* wait for the exec, but not the process */
  54        UMH_WAIT_PROC = 1,      /* wait for the process to complete */
  55};
  56
  57struct subprocess_info {
  58        struct work_struct work;
  59        struct completion *complete;
  60        char *path;
  61        char **argv;
  62        char **envp;
  63        enum umh_wait wait;
  64        int retval;
  65        int (*init)(struct subprocess_info *info, struct cred *new);
  66        void (*cleanup)(struct subprocess_info *info);
  67        void *data;
  68};
  69
  70/* Allocate a subprocess_info structure */
  71struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
  72                                                  char **envp, gfp_t gfp_mask);
  73
  74/* Set various pieces of state into the subprocess_info structure */
  75void call_usermodehelper_setfns(struct subprocess_info *info,
  76                    int (*init)(struct subprocess_info *info, struct cred *new),
  77                    void (*cleanup)(struct subprocess_info *info),
  78                    void *data);
  79
  80/* Actually execute the sub-process */
  81int call_usermodehelper_exec(struct subprocess_info *info, enum umh_wait wait);
  82
  83/* Free the subprocess_info. This is only needed if you're not going
  84   to call call_usermodehelper_exec */
  85void call_usermodehelper_freeinfo(struct subprocess_info *info);
  86
  87static inline int
  88call_usermodehelper_fns(char *path, char **argv, char **envp,
  89                        enum umh_wait wait,
  90                        int (*init)(struct subprocess_info *info, struct cred *new),
  91                        void (*cleanup)(struct subprocess_info *), void *data)
  92{
  93        struct subprocess_info *info;
  94        gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
  95
  96        info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
  97
  98        if (info == NULL)
  99                return -ENOMEM;
 100
 101        call_usermodehelper_setfns(info, init, cleanup, data);
 102
 103        return call_usermodehelper_exec(info, wait);
 104}
 105
 106static inline int
 107call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait)
 108{
 109        return call_usermodehelper_fns(path, argv, envp, wait,
 110                                       NULL, NULL, NULL);
 111}
 112
 113extern struct ctl_table usermodehelper_table[];
 114
 115extern void usermodehelper_init(void);
 116
 117extern int usermodehelper_disable(void);
 118extern void usermodehelper_enable(void);
 119extern bool usermodehelper_is_disabled(void);
 120
 121#endif /* __LINUX_KMOD_H__ */
 122