/*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*/
/*
* Copyright (c) 2015, Joyent, Inc.
*/
/*
* getrandom system call implementation
*/
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/systm.h>
#include <sys/random.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/sysmacros.h>
#include <sys/random.h>
/*
* Impose a maximum upper bound on the number of bytes that we'll read in one
* go, ala a read of /dev/random. For /dev/urandom, we clamp it based on our
* return value, because the system call returns an int, we can't handle more
* than INT_MAX.
*/
#define MAXRANDBYTES 1024
#define MAXURANDBYTES INT_MAX
int
getrandom(void *bufp, size_t buflen, int flags)
{
int out = 0;
uint8_t rbytes[128];
uint8_t *buf = bufp;
if (flags & ~(GRND_NONBLOCK | GRND_RANDOM))
return (set_errno(EINVAL));
if ((flags & GRND_RANDOM) && buflen > MAXRANDBYTES) {
buflen = MAXRANDBYTES;
} else if (buflen > MAXURANDBYTES) {
buflen = MAXURANDBYTES;
}
while (out < buflen) {
int err;
size_t len = MIN(sizeof (rbytes), buflen - out);
if (flags & GRND_RANDOM) {
if (flags & GRND_NONBLOCK)
err = random_get_bytes(rbytes, len);
else
err = random_get_blocking_bytes(rbytes, len);
} else {
err = random_get_pseudo_bytes(rbytes, len);
}
if (err == 0) {
if (ddi_copyout(rbytes, buf + out, len, 0) != 0)
return (set_errno(EFAULT));
out += len;
} else if (err == EAGAIN && out > 0) {
break;
} else {
return (set_errno(err));
}
}
return (out);
}