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 297555 2016-04-04 12:21:04Z marius $");
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 
45 static 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  */
52 int
efi_getdev(void ** vdev,const char * devspec,const char ** path)53 efi_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  */
86 static int
efi_parsedev(struct devdesc ** dev,const char * devspec,const char ** path)87 efi_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 
159 char *
efi_fmtdev(void * vdev)160 efi_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  */
185 int
efi_setcurrdev(struct env_var * ev,int flags,const void * value)186 efi_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