xref: /openbsd-src/sbin/fdisk/disk.c (revision 4c1e55dc91edd6e69ccc60ce855900fbc12cf34f)
1 /*	$OpenBSD: disk.c,v 1.33 2012/07/11 13:24:29 krw Exp $	*/
2 
3 /*
4  * Copyright (c) 1997, 2001 Tobias Weingartner
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <err.h>
29 #include <util.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <unistd.h>
33 #include <sys/fcntl.h>
34 #include <sys/ioctl.h>
35 #include <sys/dkio.h>
36 #include <sys/stdint.h>
37 #include <sys/types.h>
38 #include <sys/stat.h>
39 #include <sys/disklabel.h>
40 #include <sys/param.h>
41 #include "disk.h"
42 #include "misc.h"
43 
44 struct disklabel dl;
45 
46 DISK_metrics *DISK_getlabelmetrics(char *name);
47 
48 int
49 DISK_open(char *disk, int mode)
50 {
51 	int fd;
52 	struct stat st;
53 
54 	fd = opendev(disk, mode, OPENDEV_PART, NULL);
55 	if (fd == -1)
56 		err(1, "%s", disk);
57 	if (fstat(fd, &st) == -1)
58 		err(1, "%s", disk);
59 	if (!S_ISCHR(st.st_mode) && !S_ISREG(st.st_mode))
60 		err(1, "%s is not a character device or a regular file", disk);
61 	return (fd);
62 }
63 
64 /* Routine to go after the disklabel for geometry
65  * information.  This should work everywhere, but
66  * in the land of PC, things are not always what
67  * they seem.
68  */
69 DISK_metrics *
70 DISK_getlabelmetrics(char *name)
71 {
72 	DISK_metrics *lm = NULL;
73 	u_int64_t sz, spc;
74 	int fd;
75 
76 	/* Get label metrics */
77 	if ((fd = DISK_open(name, O_RDONLY)) != -1) {
78 		lm = malloc(sizeof(DISK_metrics));
79 		if (lm == NULL)
80 			err(1, NULL);
81 
82 		if (ioctl(fd, DIOCGPDINFO, &dl) == -1) {
83 			warn("DIOCGPDINFO");
84 			free(lm);
85 			lm = NULL;
86 		} else {
87 			lm->cylinders = dl.d_ncylinders;
88 			lm->heads = dl.d_ntracks;
89 			lm->sectors = dl.d_nsectors;
90 			/* MBR handles only first UINT32_MAX sectors. */
91 			spc = (u_int64_t)lm->heads * lm->sectors;
92 			sz = DL_GETDSIZE(&dl);
93 			if (sz > UINT32_MAX) {
94 				lm->cylinders = UINT32_MAX / spc;
95 				lm->size = lm->cylinders * spc;
96 				warnx("disk too large (%llu sectors)."
97 				    " size truncated.", sz);
98 			} else
99 				lm->size = sz;
100 			unit_types[SECTORS].conversion = dl.d_secsize;
101 		}
102 		close(fd);
103 	}
104 
105 	return (lm);
106 }
107 
108 /* This is ugly, and convoluted.  All the magic
109  * for disk geo/size happens here.  Basically,
110  * the real size is the one we will use in the
111  * rest of the program, the label size is what we
112  * got from the disklabel.  If the disklabel fails,
113  * we assume we are working with a normal file,
114  * and should request the user to specify the
115  * geometry he/she wishes to use.
116  */
117 int
118 DISK_getmetrics(disk_t *disk, DISK_metrics *user)
119 {
120 
121 	disk->label = DISK_getlabelmetrics(disk->name);
122 
123 	/* If user supplied, use that */
124 	if (user) {
125 		disk->real = user;
126 		return (0);
127 	}
128 
129 	/* If we have a label, use that */
130 	if (disk->label) {
131 		disk->real = disk->label;
132 		return (0);
133 	}
134 
135 	/* Can not get geometry, punt */
136 	disk->real = NULL;
137 	return (1);
138 }
139 
140 /*
141  * Print the disk geometry information. Take an optional modifier
142  * to indicate the units that should be used for display.
143  */
144 int
145 DISK_printmetrics(disk_t *disk, char *units)
146 {
147 	const int secsize = unit_types[SECTORS].conversion;
148 	double size;
149 	int i;
150 
151 	i = unit_lookup(units);
152 	size = ((double)disk->real->size * secsize) / unit_types[i].conversion;
153 	printf("Disk: %s\t", disk->name);
154 	if (disk->real) {
155 		printf("geometry: %d/%d/%d [%.0f ",
156 		    disk->real->cylinders, disk->real->heads,
157 		    disk->real->sectors, size);
158 		if (i == SECTORS && secsize != DEV_BSIZE)
159 			printf("%d-byte ", secsize);
160 		printf("%s]\n", unit_types[i].lname);
161 	} else
162 		printf("geometry: <none>\n");
163 
164 	return (0);
165 }
166 
167