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
  28#define KMOD_PATH_LEN 256
  29
  30#ifdef CONFIG_MODULES
  31extern char modprobe_path[]; /* for sysctl */
  32/* modprobe exit status on success, -ve on error.  Return value
  33 * usually useless though. */
  34extern 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
  41static inline int request_module(const char *name, ...) { return -ENOSYS; }
  42static inline int request_module_nowait(const char *name, ...) { return -ENOSYS; }
  43#define try_then_request_module(x, mod...) (x)
  44#endif
  45
  46
  47struct key;
  48struct file;
  49
  50enum 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
  56struct 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 */
  70struct 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 */
  74void 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 */
  80int 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 */
  84void call_usermodehelper_freeinfo(struct subprocess_info *info);
  85
  86static inline int
  87call_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
 105static inline int
 106call_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
 112extern void usermodehelper_init(void);
 113
 114extern int usermodehelper_disable(void);
 115extern void usermodehelper_enable(void);
 116
 117#endif /* __LINUX_KMOD_H__ */
 118