rwfile.c revision 256381 
1/*-
2 * Copyright (c) 2013 Mark R V Murray
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer
10 *    in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: stable/10/sys/dev/random/rwfile.c 256381 2013-10-12 15:31:36Z markm $");
30
31#include "opt_random.h"
32
33#ifdef RANDOM_RWFILE
34
35#include <sys/param.h>
36#include <sys/systm.h>
37#include <sys/kernel.h>
38#include <sys/proc.h>
39#include <sys/namei.h>
40#include <sys/fcntl.h>
41#include <sys/vnode.h>
42
43#include <dev/random/rwfile.h>
44
45int
46randomdev_read_file(const char *filename, void *buf, size_t length)
47{
48	struct nameidata nd;
49	struct thread* td = curthread;
50	int error;
51	ssize_t resid;
52	int flags;
53
54	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
55	flags = FREAD;
56	error = vn_open(&nd, &flags, 0, NULL);
57	if (error == 0) {
58		NDFREE(&nd, NDF_ONLY_PNBUF);
59		if (nd.ni_vp->v_type != VREG)
60			error = ENOEXEC;
61		else
62			error = vn_rdwr(UIO_READ, nd.ni_vp, buf, length, 0, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
63		VOP_UNLOCK(nd.ni_vp, 0);
64		vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
65	}
66
67	return (error);
68}
69
70int
71randomdev_write_file(const char *filename, void *buf, size_t length)
72{
73	struct nameidata nd;
74	struct thread* td = curthread;
75	int error;
76	ssize_t resid;
77	int flags;
78
79	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
80	flags = FWRITE | O_CREAT | O_TRUNC;
81	error = vn_open(&nd, &flags, 0, NULL);
82	if (error == 0) {
83		NDFREE(&nd, NDF_ONLY_PNBUF);
84		if (nd.ni_vp->v_type != VREG)
85			error = ENOEXEC;
86		else
87			error = vn_rdwr(UIO_WRITE, nd.ni_vp, buf, length, 0, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
88
89		VOP_UNLOCK(nd.ni_vp, 0);
90		vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
91	}
92
93	return (error);
94}
95
96#endif
97