2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2018 Conrad Meyer <cem@FreeBSD.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include "opt_compat.h"
34 #include <sys/param.h>
35 #include <sys/errno.h>
36 #include <sys/limits.h>
38 #include <sys/random.h>
39 #include <sys/sysproto.h>
40 #include <sys/systm.h>
43 #define GRND_VALIDFLAGS (GRND_NONBLOCK | GRND_RANDOM)
46 * random_read_uio(9) returns EWOULDBLOCK if a nonblocking request would block,
47 * but the Linux API name is EAGAIN. On FreeBSD, they have the same numeric
50 CTASSERT(EWOULDBLOCK == EAGAIN);
53 kern_getrandom(struct thread *td, void *user_buf, size_t buflen,
60 if ((flags & ~GRND_VALIDFLAGS) != 0)
62 if (buflen > IOSIZE_MAX)
70 aiov.iov_base = user_buf;
71 aiov.iov_len = buflen;
75 auio.uio_resid = buflen;
76 auio.uio_segflg = UIO_USERSPACE;
77 auio.uio_rw = UIO_READ;
80 error = read_random_uio(&auio, (flags & GRND_NONBLOCK) != 0);
82 td->td_retval[0] = buflen - auio.uio_resid;
86 #ifndef _SYS_SYSPROTO_H_
87 struct getrandom_args {
95 sys_getrandom(struct thread *td, struct getrandom_args *uap)
97 return (kern_getrandom(td, uap->buf, uap->buflen, uap->flags));