eibdrv_serv.c

欧洲安装总线系统的USB串口接口驱动c程序源代码.软件代码由西门子公司提供

/* ---------------------------------------------------------------------------
   eibdrv_serv.c
   ---------------------------------------------------------------------------
   eibdrv Version 0.2.1
   Copyright (C) 2002, Wolfgang Tumfart
                       Donaustrasse 104/9
                       A-2344 Maria Enzersdorf
                       Austria (Europe)
                       [e-mail]

   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 <stdio.h>
#include <stdlib.h>
#include <errno.h>

#include <linux/fcntl.h>
#include <linux/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>

#include "eibdrv.h"

void eibdrv_serv(char *device,int serv_no)
{  int eib_fd;
   int result;

   if (setsid()==-1)
   {  printf("eibdrv_serv <%i>: cannot create new session\n",serv_no);
      exit(3);
   }
   
   if (chdir("/")==-1)
   {  printf("eibdrv_serv <%i>: cannot change to root directory\n",serv_no);
      exit(3);
   }
   
   umask(0);
   
   if ((eib_fd=open(device,O_RDWR))<0)
   {  switch(result=errno)
      {  case ENOENT:
                 printf("eibdrv_serv <%i>: device node %s not found\n",serv_no,device);
                 exit(3);
         case EBUSY: 
                 printf("eibdrv_serv <%i>: module is shutdown or all server processes connected\n",serv_no);
                 exit(3);
         case ENOBUFS:
                 printf("eibdrv_serv <%i>: all server processes connected\n",serv_no);
                 exit(3);
         default:
                 printf("eibdrv_serv <%i>: cannot open device %s\n",serv_no,device);
                 exit(3);
      }
   }

   if (ioctl(eib_fd,FT_ISSERVPROC)<0)
   {  switch(result=errno)
      {  case EINVAL:
                 switch(ioctl(FT_GET_MODE))
                 {  case FT_STANDARDMODE:
                            printf("eibdrv_serv <%i>: module is loaded in standard mode\n",serv_no);
                            close(eib_fd);
                            exit(3);
                    case FT_SERVERMODE:
                            printf("eibdrv_serv <%i>: all server processes connected\n",serv_no);
                            close(eib_fd);
                            exit(3);
                 }
      }
   }
   
   if (close(eib_fd)<0)
   {  printf("eibdrv_serv <%i>: cannot close device %s\n",serv_no,device);
      exit(3);
   }
   exit(0);   
}


main(int argc,char *argv[])
{  pid_t pid1,pid2;
   
   if (argc!=2)
   {  printf("usage: eibdrv_serv node\n");
      exit(1);
   }

   switch(pid1=fork())  // fork server process 1
   {  case -1: printf("eibdrv_serv: cannot fork server process1\n");
               exit(2);
      case 0:  eibdrv_serv(argv[1],1);
               break;
   }

   switch(pid2=fork())  // fork server process 2
   {  case -1: printf("eibdrv_serv: cannot fork server process2\n");
               exit(2);
      case 0:  eibdrv_serv(argv[1],2);
               break;
   }
   
   exit(0);
}