devicename.c revision 294981 
1/*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * Copyright (c) 2006 Marcel Moolenaar
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
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 AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: stable/10/sys/boot/efi/loader/devicename.c 294981 2016-01-28 12:11:42Z smh $");
30
31#include <stand.h>
32#include <string.h>
33#include <sys/disklabel.h>
34#include <bootstrap.h>
35
36#include <efi.h>
37#include <efilib.h>
38
39#include "loader_efi.h"
40
41static int efi_parsedev(struct devdesc **, const char *, const char **);
42
43/*
44 * Point (dev) at an allocated device specifier for the device matching the
45 * path in (devspec). If it contains an explicit device specification,
46 * use that.  If not, use the default device.
47 */
48int
49efi_getdev(void **vdev, const char *devspec, const char **path)
50{
51	struct devdesc **dev = (struct devdesc **)vdev;
52	int rv;
53
54	/*
55	 * If it looks like this is just a path and no device, then
56	 * use the current device instead.
57	 */
58	if (devspec == NULL || *devspec == '/' || !strchr(devspec, ':')) {
59		rv = efi_parsedev(dev, getenv("currdev"), NULL);
60		if (rv == 0 && path != NULL)
61			*path = devspec;
62		return (rv);
63	}
64
65	/* Parse the device name off the beginning of the devspec. */
66	return (efi_parsedev(dev, devspec, path));
67}
68
69/*
70 * Point (dev) at an allocated device specifier matching the string version
71 * at the beginning of (devspec).  Return a pointer to the remaining
72 * text in (path).
73 *
74 * In all cases, the beginning of (devspec) is compared to the names
75 * of known devices in the device switch, and then any following text
76 * is parsed according to the rules applied to the device type.
77 *
78 * For disk-type devices, the syntax is:
79 *
80 * fs<unit>:
81 */
82static int
83efi_parsedev(struct devdesc **dev, const char *devspec, const char **path)
84{
85	struct devdesc *idev;
86	struct devsw *dv;
87	char *cp;
88	const char *np;
89	int i, err;
90
91	/* minimum length check */
92	if (strlen(devspec) < 2)
93		return (EINVAL);
94
95	/* look for a device that matches */
96	for (i = 0; devsw[i] != NULL; i++) {
97		dv = devsw[i];
98		if (!strncmp(devspec, dv->dv_name, strlen(dv->dv_name)))
99			break;
100	}
101	if (devsw[i] == NULL)
102		return (ENOENT);
103
104	idev = malloc(sizeof(struct devdesc));
105	if (idev == NULL)
106		return (ENOMEM);
107
108	idev->d_dev = dv;
109	idev->d_type = dv->dv_type;
110	idev->d_unit = -1;
111
112	err = 0;
113	np = devspec + strlen(dv->dv_name);
114	if (*np != '\0' && *np != ':') {
115		idev->d_unit = strtol(np, &cp, 0);
116		if (cp == np) {
117			idev->d_unit = -1;
118			free(idev);
119			return (EUNIT);
120		}
121	}
122	if (*cp != '\0' && *cp != ':') {
123		free(idev);
124		return (EINVAL);
125	}
126
127	if (path != NULL)
128		*path = (*cp == 0) ? cp : cp + 1;
129	if (dev != NULL)
130		*dev = idev;
131	else
132		free(idev);
133	return (0);
134}
135
136char *
137efi_fmtdev(void *vdev)
138{
139	struct devdesc *dev = (struct devdesc *)vdev;
140	static char buf[32];	/* XXX device length constant? */
141
142	switch(dev->d_type) {
143	case DEVT_NONE:
144		strcpy(buf, "(no device)");
145		break;
146
147	default:
148		sprintf(buf, "%s%d:", dev->d_dev->dv_name, dev->d_unit);
149		break;
150	}
151
152	return (buf);
153}
154
155/*
156 * Set currdev to suit the value being supplied in (value)
157 */
158int
159efi_setcurrdev(struct env_var *ev, int flags, const void *value)
160{
161	struct devdesc *ncurr;
162	int rv;
163
164	rv = efi_parsedev(&ncurr, value, NULL);
165	if (rv != 0)
166		return (rv);
167
168	free(ncurr);
169	env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
170	return (0);
171}
172