xref: /freebsd/usr.sbin/fstyp/hammer2.c (revision a7dea1671b87c07d2d266f836bfa8b58efc7c134)
1 /*-
2  * Copyright (c) 2017-2019 The DragonFly Project
3  * All rights reserved.
4  *
5  * This software was developed by Edward Tomasz Napierala under sponsorship
6  * from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <err.h>
37 
38 #include <sys/types.h>
39 
40 #include "hammer2_disk.h"
41 
42 #include "fstyp.h"
43 
44 static hammer2_volume_data_t*
45 __read_voldata(FILE *fp)
46 {
47 	hammer2_volume_data_t *voldata;
48 
49 	voldata = read_buf(fp, 0, sizeof(*voldata));
50 	if (voldata == NULL)
51 		err(1, "failed to read volume data");
52 
53 	return (voldata);
54 }
55 
56 static int
57 __test_voldata(const hammer2_volume_data_t *voldata)
58 {
59 	if (voldata->magic != HAMMER2_VOLUME_ID_HBO &&
60 	    voldata->magic != HAMMER2_VOLUME_ID_ABO)
61 		return (1);
62 
63 	return (0);
64 }
65 
66 static int
67 __read_label(FILE *fp, char *label, size_t size)
68 {
69 	hammer2_blockref_t broot, best, *bref;
70 	hammer2_media_data_t *vols[HAMMER2_NUM_VOLHDRS], *media;
71 	hammer2_off_t io_off, io_base;
72 	size_t bytes, io_bytes, boff;
73 	int i, best_i, error = 0;
74 
75 	best_i = -1;
76 	memset(&best, 0, sizeof(best));
77 
78 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++) {
79 		memset(&broot, 0, sizeof(broot));
80 		broot.type = HAMMER2_BREF_TYPE_VOLUME;
81 		broot.data_off = (i * HAMMER2_ZONE_BYTES64) | HAMMER2_PBUFRADIX;
82 		vols[i] = read_buf(fp, broot.data_off & ~HAMMER2_OFF_MASK_RADIX,
83 		    sizeof(*vols[i]));
84 		broot.mirror_tid = vols[i]->voldata.mirror_tid;
85 		if (best_i < 0 || best.mirror_tid < broot.mirror_tid) {
86 			best_i = i;
87 			best = broot;
88 		}
89 	}
90 
91 	bref = &vols[best_i]->voldata.sroot_blockset.blockref[0];
92 	if (bref->type != HAMMER2_BREF_TYPE_INODE) {
93 		warnx("Superroot blockref type is not inode");
94 		error = 2;
95 		goto done;
96 	}
97 
98 	bytes = bref->data_off & HAMMER2_OFF_MASK_RADIX;
99 	if (bytes)
100 		bytes = (size_t)1 << bytes;
101 	if (bytes != sizeof(hammer2_inode_data_t)) {
102 		warnx("Superroot blockref size does not match inode size");
103 		error = 3;
104 		goto done;
105 	}
106 
107 	io_off = bref->data_off & ~HAMMER2_OFF_MASK_RADIX;
108 	io_base = io_off & ~(hammer2_off_t)(HAMMER2_MINIOSIZE - 1);
109 	boff = io_off - io_base;
110 
111 	io_bytes = HAMMER2_MINIOSIZE;
112 	while (io_bytes + boff < bytes)
113 		io_bytes <<= 1;
114 	if (io_bytes > sizeof(*media)) {
115 		warnx("Invalid I/O bytes");
116 		error = 4;
117 		goto done;
118 	}
119 
120 	media = read_buf(fp, io_base, io_bytes);
121 	if (boff)
122 		memcpy(media, (char*)media + boff, bytes);
123 
124 	strlcpy(label, (char*)media->ipdata.filename, size);
125 	free(media);
126 done:
127 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++)
128 		free(vols[i]);
129 
130 	return (error);
131 }
132 
133 int
134 fstyp_hammer2(FILE *fp, char *label, size_t size)
135 {
136 	hammer2_volume_data_t *voldata;
137 	int error = 1;
138 
139 	voldata = __read_voldata(fp);
140 	if (__test_voldata(voldata))
141 		goto done;
142 
143 	error = __read_label(fp, label, size);
144 done:
145 	free(voldata);
146 	return (error);
147 }
148