1 60d3db8e 2004-04-21 devnull #include <u.h>
2 60d3db8e 2004-04-21 devnull #include <libc.h>
5 60d3db8e 2004-04-21 devnull truerand(void)
8 60d3db8e 2004-04-21 devnull uchar buf[sizeof(ulong)];
9 60d3db8e 2004-04-21 devnull static int randfd = -1;
11 60d3db8e 2004-04-21 devnull if(randfd < 0){
12 60d3db8e 2004-04-21 devnull randfd = open("/dev/random", OREAD);
13 fea3228f 2005-08-11 devnull if(randfd < 0)
14 fea3228f 2005-08-11 devnull randfd = open("/dev/srandom", OREAD); /* OpenBSD */
15 fea3228f 2005-08-11 devnull if(randfd < 0)
16 fea3228f 2005-08-11 devnull sysfatal("can't open /dev/random: %r");
17 60d3db8e 2004-04-21 devnull fcntl(randfd, F_SETFD, FD_CLOEXEC);
19 60d3db8e 2004-04-21 devnull for(i=0; i<sizeof(buf); i += n)
20 60d3db8e 2004-04-21 devnull if((n = readn(randfd, buf+i, sizeof(buf)-i)) < 0)
21 60d3db8e 2004-04-21 devnull sysfatal("can't read /dev/random: %r");
22 60d3db8e 2004-04-21 devnull return *((ulong*)buf);