devicename.c revision 332154 
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/11/stand/efi/libefi/devicename.c 332154 2018-04-06 21:37:25Z kevans $");
30
31#include <stand.h>
32#include <string.h>
33#include <sys/disklabel.h>
34#include <sys/param.h>
35#include <bootstrap.h>
36#include <disk.h>
37#ifdef EFI_ZFS_BOOT
38#include <libzfs.h>
39#endif
40
41#include <efi.h>
42#include <efilib.h>
43
44static int efi_parsedev(struct devdesc **, const char *, const char **);
45
46/*
47 * Point (dev) at an allocated device specifier for the device matching the
48 * path in (devspec). If it contains an explicit device specification,
49 * use that.  If not, use the default device.
50 */
51int
52efi_getdev(void **vdev, const char *devspec, const char **path)
53{
54	struct devdesc **dev = (struct devdesc **)vdev;
55	int rv;
56
57	/*
58	 * If it looks like this is just a path and no device, then
59	 * use the current device instead.
60	 */
61	if (devspec == NULL || *devspec == '/' || !strchr(devspec, ':')) {
62		rv = efi_parsedev(dev, getenv("currdev"), NULL);
63		if (rv == 0 && path != NULL)
64			*path = devspec;
65		return (rv);
66	}
67
68	/* Parse the device name off the beginning of the devspec. */
69	return (efi_parsedev(dev, devspec, path));
70}
71
72/*
73 * Point (dev) at an allocated device specifier matching the string version
74 * at the beginning of (devspec).  Return a pointer to the remaining
75 * text in (path).
76 *
77 * In all cases, the beginning of (devspec) is compared to the names
78 * of known devices in the device switch, and then any following text
79 * is parsed according to the rules applied to the device type.
80 *
81 * For disk-type devices, the syntax is:
82 *
83 * fs<unit>:
84 */
85static int
86efi_parsedev(struct devdesc **dev, const char *devspec, const char **path)
87{
88	struct devdesc *idev;
89	struct devsw *dv;
90	int i, unit, err;
91	char *cp;
92	const char *np;
93
94	/* minimum length check */
95	if (strlen(devspec) < 2)
96		return (EINVAL);
97
98	/* look for a device that matches */
99	for (i = 0; devsw[i] != NULL; i++) {
100		dv = devsw[i];
101		if (!strncmp(devspec, dv->dv_name, strlen(dv->dv_name)))
102			break;
103	}
104	if (devsw[i] == NULL)
105		return (ENOENT);
106
107	np = devspec + strlen(dv->dv_name);
108	idev = NULL;
109	err = 0;
110
111	switch (dv->dv_type) {
112	case DEVT_NONE:
113		break;
114
115	case DEVT_DISK:
116		idev = malloc(sizeof(struct disk_devdesc));
117		if (idev == NULL)
118			return (ENOMEM);
119
120		err = disk_parsedev((struct disk_devdesc *)idev, np, path);
121		if (err != 0)
122			goto fail;
123		break;
124
125#ifdef EFI_ZFS_BOOT
126	case DEVT_ZFS:
127		idev = malloc(sizeof(struct zfs_devdesc));
128		if (idev == NULL)
129			return (ENOMEM);
130
131		err = zfs_parsedev((struct zfs_devdesc*)idev, np, path);
132		if (err != 0)
133			goto fail;
134		break;
135#endif
136	default:
137		idev = malloc(sizeof(struct devdesc));
138		if (idev == NULL)
139			return (ENOMEM);
140
141		unit = 0;
142		cp = (char *)np;
143
144		if (*np != '\0' && *np != ':') {
145			errno = 0;
146			unit = strtol(np, &cp, 0);
147			if (errno != 0 || cp == np) {
148				err = EUNIT;
149				goto fail;
150			}
151		}
152		if (*cp != '\0' && *cp != ':') {
153			err = EINVAL;
154			goto fail;
155		}
156
157		idev->d_unit = unit;
158		if (path != NULL)
159			*path = (*cp == 0) ? cp : cp + 1;
160		break;
161	}
162
163	idev->d_dev = dv;
164
165	if (dev != NULL)
166		*dev = idev;
167	else
168		free(idev);
169	return (0);
170
171fail:
172	free(idev);
173	return (err);
174}
175
176char *
177efi_fmtdev(void *vdev)
178{
179	struct devdesc *dev = (struct devdesc *)vdev;
180	static char buf[SPECNAMELEN + 1];
181
182	switch(dev->d_dev->dv_type) {
183	case DEVT_NONE:
184		strcpy(buf, "(no device)");
185		break;
186
187	case DEVT_DISK:
188		return (disk_fmtdev(vdev));
189
190#ifdef EFI_ZFS_BOOT
191	case DEVT_ZFS:
192		return (zfs_fmtdev(dev));
193#endif
194	default:
195		sprintf(buf, "%s%d:", dev->d_dev->dv_name, dev->d_unit);
196		break;
197	}
198
199	return (buf);
200}
201
202/*
203 * Set currdev to suit the value being supplied in (value)
204 */
205int
206efi_setcurrdev(struct env_var *ev, int flags, const void *value)
207{
208	struct devdesc *ncurr;
209	int rv;
210
211	rv = efi_parsedev(&ncurr, value, NULL);
212	if (rv != 0)
213		return (rv);
214
215	free(ncurr);
216	env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
217	return (0);
218}
219