1 60d3db8e 2004-04-21 devnull #include <u.h>
 2 60d3db8e 2004-04-21 devnull #include <libc.h>
 3 60d3db8e 2004-04-21 devnull 
 4 60d3db8e 2004-04-21 devnull ulong
 5 60d3db8e 2004-04-21 devnull truerand(void)
 6 60d3db8e 2004-04-21 devnull {
 7 60d3db8e 2004-04-21 devnull 	int i, n;
 8 60d3db8e 2004-04-21 devnull 	uchar buf[sizeof(ulong)];
 9 60d3db8e 2004-04-21 devnull 	static int randfd = -1;
10 60d3db8e 2004-04-21 devnull 
11 60d3db8e 2004-04-21 devnull 	if(randfd < 0){
12 60d3db8e 2004-04-21 devnull 		randfd = open("/dev/random", OREAD);
13 60d3db8e 2004-04-21 devnull 		fcntl(randfd, F_SETFD, FD_CLOEXEC);
14 60d3db8e 2004-04-21 devnull 	}
15 60d3db8e 2004-04-21 devnull 	if(randfd < 0)
16 60d3db8e 2004-04-21 devnull 		sysfatal("can't open /dev/random: %r");
17 60d3db8e 2004-04-21 devnull 	for(i=0; i<sizeof(buf); i += n)
18 60d3db8e 2004-04-21 devnull 		if((n = readn(randfd, buf+i, sizeof(buf)-i)) < 0)
19 60d3db8e 2004-04-21 devnull 			sysfatal("can't read /dev/random: %r");
20 60d3db8e 2004-04-21 devnull 	return *((ulong*)buf);
21 60d3db8e 2004-04-21 devnull }