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/*
Unix SMB/Netbios implementation.
Version 1.9.
external program running routine
Copyright (C) Andrew Tridgell 1992-1997
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[])
{
int uid,gid;
close_fds();
if (argc != 4) exit(2);
uid = atoi(argv[1]);
gid = atoi(argv[2]);
/* first become root - we may need to do this in order to lose
our privilages! */
#ifdef USE_SETRES
setresgid(0,0,0);
setresuid(0,0,0);
#else
setuid(0);
seteuid(0);
#endif
#ifdef USE_SETFS
setfsuid(uid);
setfsgid(gid);
#endif
#ifdef USE_SETRES
setresgid(gid,gid,gid);
setresuid(uid,uid,uid);
#else
setgid(gid);
setegid(gid);
setuid(uid);
seteuid(uid);
#endif
/* 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]));
}
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