text: /* 
     Unix SMB/Netbios implementation.
     Version 1.9.
     external program running routine
     Copyright (C) Andrew Tridgell 1992-1998
     
     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 "includes.h"
  
  
  /*******************************************************************
  close the low 3 fd's and open dev/null in their place
  ********************************************************************/
  static void close_fds(void)
  {
    int fd;
    int i;
    close(0); close(1); close(2);
    /* try and use up these file descriptors, so silly
       library routines writing to stdout etc won't cause havoc */
    for (i=0;i<3;i++) {
      fd = open("/dev/null",O_RDWR,0);
      if (fd < 0) fd = open("/dev/null",O_WRONLY,0);
      if (fd != i) return;
    }
  }
  
  
  /*
  This is a wrapper around the system() call to allow commands to run correctly 
  as non root from a program which is switching between root and non-root 
  
  It takes 3 arguments as uid,gid,command and runs command after
  becoming a non-root user */
   int main(int argc,char *argv[])
  {
    uid_t uid;
    gid_t gid;
  
    close_fds();
  
    if (argc != 4) exit(2);
  
    uid = (uid_t)atoi(argv[1]);
    gid = (gid_t)atoi(argv[2]);
  
    become_user_permanently( uid, gid);
  
    /* paranoia :-) */
    if (getuid() != uid)
      return(3);
  
    if (geteuid() != getuid())
      return(4);
  
    /* this is to make sure that the system() call doesn't run forever */
    alarm(30);
  
    return(system(argv[3]));
  }
  