xref: /freebsd/stand/efi/libefi/devicename.c (revision 1e7a2eb93a527a2f4b22be66788caf50e4ba1f89)
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("$FreeBSD$");
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 
38 #include <efi.h>
39 #include <efilib.h>
40 #include <efizfs.h>
41 
42 static int efi_parsedev(struct devdesc **, const char *, const char **);
43 
44 /*
45  * Point (dev) at an allocated device specifier for the device matching the
46  * path in (devspec). If it contains an explicit device specification,
47  * use that.  If not, use the default device.
48  */
49 int
50 efi_getdev(void **vdev, const char *devspec, const char **path)
51 {
52 	struct devdesc **dev = (struct devdesc **)vdev;
53 	int rv;
54 
55 	/*
56 	 * If it looks like this is just a path and no device, then
57 	 * use the current device instead.
58 	 */
59 	if (devspec == NULL || *devspec == '/' || !strchr(devspec, ':')) {
60 		rv = efi_parsedev(dev, getenv("currdev"), NULL);
61 		if (rv == 0 && path != NULL)
62 			*path = devspec;
63 		return (rv);
64 	}
65 
66 	/* Parse the device name off the beginning of the devspec. */
67 	return (efi_parsedev(dev, devspec, path));
68 }
69 
70 /*
71  * Point (dev) at an allocated device specifier matching the string version
72  * at the beginning of (devspec).  Return a pointer to the remaining
73  * text in (path).
74  *
75  * In all cases, the beginning of (devspec) is compared to the names
76  * of known devices in the device switch, and then any following text
77  * is parsed according to the rules applied to the device type.
78  *
79  * For disk-type devices, the syntax is:
80  *
81  * fs<unit>:
82  */
83 static int
84 efi_parsedev(struct devdesc **dev, const char *devspec, const char **path)
85 {
86 	struct devdesc *idev;
87 	struct devsw *dv;
88 	int i, unit, err;
89 	char *cp;
90 	const char *np;
91 
92 	/* minimum length check */
93 	if (strlen(devspec) < 2)
94 		return (EINVAL);
95 
96 	/* look for a device that matches */
97 	for (i = 0; devsw[i] != NULL; i++) {
98 		dv = devsw[i];
99 		if (!strncmp(devspec, dv->dv_name, strlen(dv->dv_name)))
100 			break;
101 	}
102 	if (devsw[i] == NULL)
103 		return (ENOENT);
104 
105 	np = devspec + strlen(dv->dv_name);
106 	idev = NULL;
107 	err = 0;
108 
109 	switch (dv->dv_type) {
110 	case DEVT_NONE:
111 		break;
112 
113 	case DEVT_DISK:
114 		idev = malloc(sizeof(struct disk_devdesc));
115 		if (idev == NULL)
116 			return (ENOMEM);
117 
118 		err = disk_parsedev((struct disk_devdesc *)idev, np, path);
119 		if (err != 0)
120 			goto fail;
121 		break;
122 
123 #ifdef EFI_ZFS_BOOT
124 	case DEVT_ZFS:
125 		idev = malloc(sizeof(struct zfs_devdesc));
126 		if (idev == NULL)
127 			return (ENOMEM);
128 
129 		err = zfs_parsedev((struct zfs_devdesc*)idev, np, path);
130 		if (err != 0)
131 			goto fail;
132 		break;
133 #endif
134 	default:
135 		idev = malloc(sizeof(struct devdesc));
136 		if (idev == NULL)
137 			return (ENOMEM);
138 
139 		unit = 0;
140 		cp = (char *)np;
141 
142 		if (*np != '\0' && *np != ':') {
143 			errno = 0;
144 			unit = strtol(np, &cp, 0);
145 			if (errno != 0 || cp == np) {
146 				err = EUNIT;
147 				goto fail;
148 			}
149 		}
150 		if (*cp != '\0' && *cp != ':') {
151 			err = EINVAL;
152 			goto fail;
153 		}
154 
155 		idev->d_unit = unit;
156 		if (path != NULL)
157 			*path = (*cp == 0) ? cp : cp + 1;
158 		break;
159 	}
160 
161 	idev->d_dev = dv;
162 
163 	if (dev != NULL)
164 		*dev = idev;
165 	else
166 		free(idev);
167 	return (0);
168 
169 fail:
170 	free(idev);
171 	return (err);
172 }
173 
174 /*
175  * Set currdev to suit the value being supplied in (value)
176  */
177 int
178 efi_setcurrdev(struct env_var *ev, int flags, const void *value)
179 {
180 	struct devdesc *ncurr;
181 	int rv;
182 
183 	rv = efi_parsedev(&ncurr, value, NULL);
184 	if (rv != 0)
185 		return (rv);
186 	free(ncurr);
187 
188 	return (mount_currdev(ev, flags, value));
189 }
190