rtl_posixio_fake.h

最新rtlinux内核源码

/*

 This file has been written by Sergio Perez Alca駃z
 <[e-mail]> 

 Departamento de Inform醫ica de Sistemas y Computadores
 Universidad Polit閏nica de Valencia Valencia (Spain)
 Date: December 2004

 Copyright (c) December,   2004 SISTEMAS  DE TIEMPO  REAL  EMPOTRADOS,
 FIABLES Y DISTRIBUIDOS BASADOS EN COMPONENTES

 Released under  the terms of the GNU  General  Public License Version
 2.0

 rtl_posixio_fake.h: This file  allows  other applications to  build a
 software layer over the driver, substituting the driver's open, read,
 write, ioctl and  close calls with  the other applications owns (that
 can still use the  older calls to  send and receive). That  allows to
 execute "extra" code before executing  -for example- the code of  the
 read call while keeping  this  substitution transparent to  the final
 user (who will finally call read).

 As said before, the main idea of this code is to provide the basis to
 build a software layer over the  driver in a transparent manner. This
 could be useful,  for example, to develope  a real-time protocol over
 Ethernet while providing the same standard (POSIX) interface.

 If  compiled  with  the  _TEST_FAKE_   option,  the   next  code will
 substitute the driver's read, write, open, close and ioctl calls with
 the   rtl_{read,write,open,close,ioctl}_fake   functions, function(s)
 that first prints "FAKE!!" and finally calls the corresponding driver
 call.

*/


#ifdef _FAKE_DRIVER_

#ifndef _TEST_FAKE_

extern ssize_t (*oldread) (struct rtl_file *, char *, size_t, loff_t *);
extern ssize_t (*oldwrite) (struct rtl_file *, const char *, size_t, loff_t *);
extern int (*oldioctl) (struct rtl_file *, unsigned int, unsigned long);
extern int (*oldopen) (struct rtl_file *);
extern int (*oldrelease) (struct rtl_file *);

extern ssize_t rtl_read_fake(struct rtl_file *filp, char *buf, size_t count, loff_t* ppos);
extern ssize_t rtl_write_fake(struct rtl_file *filp, const char *buf, size_t count, loff_t* ppos);
extern int rtl_ioctl_fake(struct rtl_file * filp, unsigned int request, unsigned long other);
extern int rtl_open_fake (struct rtl_file *filp);
extern int rtl_release_fake (struct rtl_file *filp);

#else

ssize_t (*oldread) (struct rtl_file *, char *, size_t, loff_t *);
ssize_t (*oldwrite) (struct rtl_file *, const char *, size_t, loff_t *);
int (*oldioctl) (struct rtl_file *, unsigned int, unsigned long);
int (*oldopen) (struct rtl_file *);
int (*oldrelease) (struct rtl_file *);

static ssize_t rtl_read_fake(struct rtl_file *filp, char *buf, size_t count, loff_t* ppos){
  rtl_printf("READ FAKE!!\n");
  return oldread(filp, buf, count, ppos);
}

static ssize_t rtl_write_fake(struct rtl_file *filp, const char *buf, size_t count, loff_t* ppos){
  rtl_printf("WRITE FAKE!!\n");
  return oldwrite(filp, buf, count, ppos);
}

static int rtl_ioctl_fake(struct rtl_file * filp, unsigned int request, unsigned long other){
  rtl_printf("IOCTL FAKE!!\n");
  return oldioctl(filp, request, other);
}

static int rtl_open_fake (struct rtl_file *filp){
  rtl_printf("OPEN FAKE!!\n");
  return oldopen(filp);
}

static int rtl_release_fake (struct rtl_file *filp){
  rtl_printf("CLOSE FAKE!!\n");
  return oldrelease(filp);
}

#endif

static void init(void){

  //This code   saves  a  pointer  to  the   driver's  read call   and
  //substitutes that call with the fake one
  oldread = fops->read;
  fops->read = rtl_read_fake;

  //This  code saves   a pointer  to    the driver's  write  call  and
  //substitutes that call with the fake one
  oldwrite = fops->write;
  fops->write = rtl_write_fake;

  //This  code    saves a  pointer   to the  driver's   ioctl call and
  //substitutes that call with the fake one
  oldioctl = fops->ioctl;
  fops->ioctl = rtl_ioctl_fake;

  //This  code  saves  a  pointer  to   the   driver's  open call  and
  //substitutes that call with the fake one
  oldopen = fops->open;
  fops->open = rtl_open_fake;

  //This code  saves   a pointer to  the  driver's  read  release  and
  //substitutes that call with the fake one
  oldrelease = fops->release;
  fops->release = rtl_release_fake;
}
#endif