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	2000-09-26 Ulrich Drepper <drepper@redhat.com> * sysdeps/unix/sysv/linux/gethostid.c (sethostid): Use O_TRUNC to remove possible garbage at the end of the file. * stdio-common/tmpnam_r.c: Warn about insecure tmpnam_r. * stdio-common/tmpnam.c: Warn about insecure tmpnam. * stdio-common/tempnam.c: Warn about insecure tempnam. * misc/mktemp.c: Warn about insecure mktemp.
		
			
				
	
	
		
			117 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			117 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Copyright (C) 1995, 1996, 1998, 1999, 2000 Free Software Foundation, Inc.
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| 
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|    The GNU C Library is free software; you can redistribute it and/or
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|    modify it under the terms of the GNU Library General Public License as
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|    published by the Free Software Foundation; either version 2 of the
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|    License, or (at your option) any later version.
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| 
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|    The GNU C Library is distributed in the hope that it will be useful,
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|    but WITHOUT ANY WARRANTY; without even the implied warranty of
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|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|    Library General Public License for more details.
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| 
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|    You should have received a copy of the GNU Library General Public
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|    License along with the GNU C Library; see the file COPYING.LIB.  If not,
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|    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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|    Boston, MA 02111-1307, USA.  */
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| 
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| #include <alloca.h>
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| #include <errno.h>
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| #include <fcntl.h>
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| #include <unistd.h>
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| #include <netdb.h>
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| 
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| #define HOSTIDFILE "/etc/hostid"
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| #define OLD_HOSTIDFILE "/etc/hostid"
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| 
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| #ifdef SET_PROCEDURE
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| int
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| sethostid (id)
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|      long int id;
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| {
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|   int fd;
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|   ssize_t written;
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| 
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|   /* Test for appropriate rights to set host ID.  */
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|   if (__libc_enable_secure)
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|     {
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|       __set_errno (EPERM);
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|       return -1;
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|     }
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| 
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|   /* Open file for writing.  Everybody is allowed to read this file.  */
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|   fd = __open (HOSTIDFILE, O_CREAT|O_WRONLY|O_TRUNC, 0644);
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|   if (fd < 0)
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|     return -1;
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| 
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|   written = __write (fd, &id, sizeof (id));
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| 
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|   __close (fd);
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| 
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|   return written != sizeof (id) ? -1 : 0;
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| }
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| 
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| #else
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| # include <string.h>
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| # include <sys/param.h>
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| # include <resolv/netdb.h>
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| # include <netinet/in.h>
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| 
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| long int
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| gethostid ()
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| {
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|   char hostname[MAXHOSTNAMELEN + 1];
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|   size_t buflen;
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|   char *buffer;
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|   struct hostent hostbuf, *hp;
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|   unsigned long int id;
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|   struct in_addr in;
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|   int herr;
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|   int fd;
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| 
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|   /* First try to get the ID from a former invocation of sethostid.  */
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|   fd = __open (HOSTIDFILE, O_RDONLY);
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|   if (fd < 0)
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|     fd = __open (OLD_HOSTIDFILE, O_RDONLY);
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|   if (fd >= 0)
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|     {
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|       ssize_t n = __read (fd, &id, sizeof (id));
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| 
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|       __close (fd);
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| 
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|       if (n == sizeof (id))
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| 	return id;
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|     }
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| 
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|   /* Getting from the file was not successful.  An intelligent guess for
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|      a unique number of a host is its IP address.  Return this.  */
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|   if (__gethostname (hostname, MAXHOSTNAMELEN) < 0 || hostname[0] == '\0')
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|     /* This also fails.  Return and arbitrary value.  */
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|     return 0;
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| 
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|   buflen = 1024;
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|   buffer = __alloca (buflen);
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| 
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|   /* To get the IP address we need to know the host name.  */
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|   while (__gethostbyname_r (hostname, &hostbuf, buffer, buflen, &hp, &herr)
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| 	 != 0
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| 	 || hp == NULL)
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|     if (herr != NETDB_INTERNAL || errno != ERANGE)
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|       return 0;
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|     else
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|       {
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| 	/* Enlarge buffer.  */
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| 	buflen *= 2;
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| 	buffer = __alloca (buflen);
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|       }
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| 
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|   in.s_addr = 0;
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|   memcpy (&in, hp->h_addr,
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| 	  (int) sizeof (in) < hp->h_length ? sizeof (in) : hp->h_length);
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| 
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|   /* For the return value to be not exactly the IP address we do some
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|      bit fiddling.  */
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|   return in.s_addr << 16 | in.s_addr >> 16;
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| }
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| #endif
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