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/* $OpenBSD: kqueue-random.c,v 1.5 2011/01/07 06:17:33 deraadt Exp $ */
/* Written by Michael Shalayeff, 2002, Public Domain */
#include <stdlib.h>
#include <stdio.h>
#include <err.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/event.h>
#include <sys/wait.h>
#include <sys/fcntl.h>
#include <dev/rndvar.h>
int do_random(void);
int
do_random(void)
{
int n, fd, kq;
struct timespec ts;
struct kevent ev;
u_int32_t buf[BUFSIZ];
if ((fd = open("/dev/srandom", O_RDONLY)) < 0) {
warn("open: /dev/srandom");
return (1);
}
if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
warn("fcntl");
close(fd);
return (1);
}
if ((kq = kqueue()) < 0) {
warn("kqueue");
close(fd);
return (1);
}
ev.ident = fd;
ev.filter = EVFILT_READ;
ev.flags = EV_ADD | EV_ENABLE;
n = kevent(kq, &ev, 1, NULL, 0, NULL);
if (n == -1) {
warn("kevent");
close(kq);
close(fd);
return (1);
}
ts.tv_sec = 0;
ts.tv_nsec = 0;
if (kevent(kq, NULL, 0, &ev, 1, &ts) < 0) {
warn("kevent2");
return (1);
}
n = MIN((ev.data + 7) / 8, sizeof(buf));
if (read(fd, buf, n) < 1)
return (1);
close(kq);
close(fd);
return (0);
}
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