devicename.c revision 294999 
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 294999 2016-01-28 17:24:40Z smh $");
30
31#include <stand.h>
32#include <string.h>
33#include <sys/disklabel.h>
34#include <sys/param.h>
35#include <bootstrap.h>
36#ifdef EFI_ZFS_BOOT
37#include <libzfs.h>
38#endif
39
40#include <efi.h>
41#include <efilib.h>
42
43#include "loader_efi.h"
44
45static int efi_parsedev(struct devdesc **, const char *, const char **);
46
47/*
48 * Point (dev) at an allocated device specifier for the device matching the
49 * path in (devspec). If it contains an explicit device specification,
50 * use that.  If not, use the default device.
51 */
52int
53efi_getdev(void **vdev, const char *devspec, const char **path)
54{
55	struct devdesc **dev = (struct devdesc **)vdev;
56	int rv;
57
58	/*
59	 * If it looks like this is just a path and no device, then
60	 * use the current device instead.
61	 */
62	if (devspec == NULL || *devspec == '/' || !strchr(devspec, ':')) {
63		rv = efi_parsedev(dev, getenv("currdev"), NULL);
64		if (rv == 0 && path != NULL)
65			*path = devspec;
66		return (rv);
67	}
68
69	/* Parse the device name off the beginning of the devspec. */
70	return (efi_parsedev(dev, devspec, path));
71}
72
73/*
74 * Point (dev) at an allocated device specifier matching the string version
75 * at the beginning of (devspec).  Return a pointer to the remaining
76 * text in (path).
77 *
78 * In all cases, the beginning of (devspec) is compared to the names
79 * of known devices in the device switch, and then any following text
80 * is parsed according to the rules applied to the device type.
81 *
82 * For disk-type devices, the syntax is:
83 *
84 * fs<unit>:
85 */
86static int
87efi_parsedev(struct devdesc **dev, const char *devspec, const char **path)
88{
89	struct devdesc *idev;
90	struct devsw *dv;
91	char *cp;
92	const char *np;
93	int i;
94
95	/* minimum length check */
96	if (strlen(devspec) < 2)
97		return (EINVAL);
98
99	/* look for a device that matches */
100	for (i = 0; devsw[i] != NULL; i++) {
101		dv = devsw[i];
102		if (!strncmp(devspec, dv->dv_name, strlen(dv->dv_name)))
103			break;
104	}
105	if (devsw[i] == NULL)
106		return (ENOENT);
107
108	np = devspec + strlen(dv->dv_name);
109
110#ifdef EFI_ZFS_BOOT
111	if (dv->dv_type == DEVT_ZFS) {
112		int err;
113
114		idev = malloc(sizeof(struct zfs_devdesc));
115		if (idev == NULL)
116			return (ENOMEM);
117
118		err = zfs_parsedev((struct zfs_devdesc*)idev, np, path);
119		if (err != 0) {
120			free(idev);
121			return (err);
122		}
123		*dev = idev;
124		cp = strchr(np + 1, ':');
125	} else
126#endif
127	{
128		idev = malloc(sizeof(struct devdesc));
129		if (idev == NULL)
130			return (ENOMEM);
131
132		idev->d_dev = dv;
133		idev->d_type = dv->dv_type;
134		idev->d_unit = -1;
135		if (*np != '\0' && *np != ':') {
136			idev->d_unit = strtol(np, &cp, 0);
137			if (cp == np) {
138				idev->d_unit = -1;
139				free(idev);
140				return (EUNIT);
141			}
142		}
143	}
144
145	if (*cp != '\0' && *cp != ':') {
146		free(idev);
147		return (EINVAL);
148	}
149
150	if (path != NULL)
151		*path = (*cp == 0) ? cp : cp + 1;
152	if (dev != NULL)
153		*dev = idev;
154	else
155		free(idev);
156	return (0);
157}
158
159char *
160efi_fmtdev(void *vdev)
161{
162	struct devdesc *dev = (struct devdesc *)vdev;
163	static char buf[SPECNAMELEN + 1];
164
165	switch(dev->d_type) {
166#ifdef EFI_ZFS_BOOT
167	case DEVT_ZFS:
168		return (zfs_fmtdev(dev));
169#endif
170	case DEVT_NONE:
171		strcpy(buf, "(no device)");
172		break;
173
174	default:
175		sprintf(buf, "%s%d:", dev->d_dev->dv_name, dev->d_unit);
176		break;
177	}
178
179	return (buf);
180}
181
182/*
183 * Set currdev to suit the value being supplied in (value)
184 */
185int
186efi_setcurrdev(struct env_var *ev, int flags, const void *value)
187{
188	struct devdesc *ncurr;
189	int rv;
190
191	rv = efi_parsedev(&ncurr, value, NULL);
192	if (rv != 0)
193		return (rv);
194
195	free(ncurr);
196	env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
197	return (0);
198}
199