root/include/linux/kmod.h

INCLUDED FROM

DEFINITIONS

1. request_module
2. call_usermodehelper
3. call_usermodehelper_keys

#ifndef __LINUX_KMOD_H__
#define __LINUX_KMOD_H__

/*
 *      include/linux/kmod.h
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/gfp.h>
#include <linux/stddef.h>
#include <linux/errno.h>
#include <linux/compiler.h>

#define KMOD_PATH_LEN 256

#ifdef CONFIG_MODULES
/* modprobe exit status on success, -ve on error.  Return value
 * usually useless though. */
extern int request_module(const char * name, ...) __attribute__ ((format (printf, 1, 2)));
#define try_then_request_module(x, mod...) ((x) ?: (request_module(mod), (x)))
#else
static inline int request_module(const char * name, ...) { return -ENOSYS; }
#define try_then_request_module(x, mod...) (x)
#endif


struct key;
struct file;
struct subprocess_info;

/* Allocate a subprocess_info structure */
struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
                                                  char **envp, gfp_t gfp_mask);

/* Set various pieces of state into the subprocess_info structure */
void call_usermodehelper_setkeys(struct subprocess_info *info,
                                 struct key *session_keyring);
int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info,
                                  struct file **filp);
void call_usermodehelper_setcleanup(struct subprocess_info *info,
                                    void (*cleanup)(char **argv, char **envp));

enum umh_wait {
        UMH_NO_WAIT = -1,       /* don't wait at all */
        UMH_WAIT_EXEC = 0,      /* wait for the exec, but not the process */
        UMH_WAIT_PROC = 1,      /* wait for the process to complete */
};

/* Actually execute the sub-process */
int call_usermodehelper_exec(struct subprocess_info *info, enum umh_wait wait);

/* Free the subprocess_info. This is only needed if you're not going
   to call call_usermodehelper_exec */
void call_usermodehelper_freeinfo(struct subprocess_info *info);

static inline int
call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait)
{
        struct subprocess_info *info;
        gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;

        info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
        if (info == NULL)
                return -ENOMEM;
        return call_usermodehelper_exec(info, wait);
}

static inline int
call_usermodehelper_keys(char *path, char **argv, char **envp,
                         struct key *session_keyring, enum umh_wait wait)
{
        struct subprocess_info *info;
        gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;

        info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
        if (info == NULL)
                return -ENOMEM;

        call_usermodehelper_setkeys(info, session_keyring);
        return call_usermodehelper_exec(info, wait);
}

extern void usermodehelper_init(void);

struct file;
extern int call_usermodehelper_pipe(char *path, char *argv[], char *envp[],
                                    struct file **filp);

#endif /* __LINUX_KMOD_H__ */