magic.c
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上传日期:2007-01-17
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文件大小:2k
- /* magic.c - PPP Magic Number routines */
- /* Copyright 1995 Wind River Systems, Inc. */
- #include "copyright_wrs.h"
- /*
- * Copyright (c) 1989 Carnegie Mellon University.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms are permitted
- * provided that the above copyright notice and this paragraph are
- * duplicated in all such forms and that any documentation,
- * advertising materials, and other materials related to such
- * distribution and use acknowledge that the software was developed
- * by Carnegie Mellon University. The name of the
- * University may not be used to endorse or promote products derived
- * from this software without specific prior written permission.
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
- * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
- */
- /*
- modification history
- --------------------
- 01b,16jun95,dzb header file consolidation.
- 01a,21dec94,dab VxWorks port - first WRS version.
- +dzb added: path for ppp header files, WRS copyright, tickLib.h.
- */
- #include "vxWorks.h"
- #include "tickLib.h"
- #include "sys/types.h"
- #include "sys/times.h"
- #include "pppLib.h"
- static u_long next; /* Next value to return */
- extern u_long gethostid __ARGS((void));
- /*
- * magic_init - Initialize the magic number generator.
- *
- * Computes first magic number and seed for random number generator.
- * Attempts to compute a random number seed which will not repeat.
- * The current method uses the current hostid and current time.
- */
- void magic_init()
- {
- next = tickGet();
- srandom((int) next);
- }
- /*
- * magic - Returns the next magic number.
- */
- u_long magic()
- {
- u_long m;
- m = next;
- next = (u_long) random();
- return (m);
- }