xref: /freebsd/usr.sbin/fstyp/hammer2.c (revision b0d29bc47dba79f6f38e67eabadfb4b32ffd9390)
1 /*-
2  * Copyright (c) 2017-2019 The DragonFly Project
3  * Copyright (c) 2017-2019 Tomohiro Kusumi <tkusumi@netbsd.org>
4  * All rights reserved.
5  *
6  * This software was developed by Edward Tomasz Napierala under sponsorship
7  * from the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <stdbool.h>
37 #include <string.h>
38 #include <err.h>
39 #include <assert.h>
40 
41 #include <sys/types.h>
42 
43 #include "hammer2_disk.h"
44 
45 #include "fstyp.h"
46 
47 static hammer2_volume_data_t*
48 read_voldata(FILE *fp)
49 {
50 	hammer2_volume_data_t *voldata;
51 
52 	voldata = read_buf(fp, 0, sizeof(*voldata));
53 	if (voldata == NULL)
54 		err(1, "failed to read volume data");
55 
56 	return (voldata);
57 }
58 
59 static int
60 test_voldata(const hammer2_volume_data_t *voldata)
61 {
62 	if (voldata->magic != HAMMER2_VOLUME_ID_HBO &&
63 	    voldata->magic != HAMMER2_VOLUME_ID_ABO)
64 		return (1);
65 
66 	return (0);
67 }
68 
69 static hammer2_media_data_t*
70 read_media(FILE *fp, const hammer2_blockref_t *bref, size_t *media_bytes)
71 {
72 	hammer2_media_data_t *media;
73 	hammer2_off_t io_off, io_base;
74 	size_t bytes, io_bytes, boff;
75 
76 	bytes = (bref->data_off & HAMMER2_OFF_MASK_RADIX);
77 	if (bytes)
78 		bytes = (size_t)1 << bytes;
79 	*media_bytes = bytes;
80 
81 	if (!bytes) {
82 		warnx("blockref has no data");
83 		return (NULL);
84 	}
85 
86 	io_off = bref->data_off & ~HAMMER2_OFF_MASK_RADIX;
87 	io_base = io_off & ~(hammer2_off_t)(HAMMER2_MINIOSIZE - 1);
88 	boff = io_off - io_base;
89 
90 	io_bytes = HAMMER2_MINIOSIZE;
91 	while (io_bytes + boff < bytes)
92 		io_bytes <<= 1;
93 
94 	if (io_bytes > sizeof(hammer2_media_data_t)) {
95 		warnx("invalid I/O bytes");
96 		return (NULL);
97 	}
98 
99 	if (fseek(fp, io_base, SEEK_SET) == -1) {
100 		warnx("failed to seek media");
101 		return (NULL);
102 	}
103 	media = read_buf(fp, io_base, io_bytes);
104 	if (media == NULL) {
105 		warnx("failed to read media");
106 		return (NULL);
107 	}
108 	if (boff)
109 		memcpy(media, (char *)media + boff, bytes);
110 
111 	return (media);
112 }
113 
114 static int
115 find_pfs(FILE *fp, const hammer2_blockref_t *bref, const char *pfs, bool *res)
116 {
117 	hammer2_media_data_t *media;
118 	hammer2_inode_data_t ipdata;
119 	hammer2_blockref_t *bscan;
120 	size_t bytes;
121 	int i, bcount;
122 
123 	media = read_media(fp, bref, &bytes);
124 	if (media == NULL)
125 		return (-1);
126 
127 	switch (bref->type) {
128 	case HAMMER2_BREF_TYPE_INODE:
129 		ipdata = media->ipdata;
130 		if (ipdata.meta.pfs_type & HAMMER2_PFSTYPE_SUPROOT) {
131 			bscan = &ipdata.u.blockset.blockref[0];
132 			bcount = HAMMER2_SET_COUNT;
133 		} else {
134 			bscan = NULL;
135 			bcount = 0;
136 			if (ipdata.meta.op_flags & HAMMER2_OPFLAG_PFSROOT) {
137 				if (memchr(ipdata.filename, 0,
138 				    sizeof(ipdata.filename))) {
139 					if (!strcmp(
140 					    (const char*)ipdata.filename, pfs))
141 						*res = true;
142 				} else {
143 					if (strlen(pfs) > 0 &&
144 					    !memcmp(ipdata.filename, pfs,
145 					    strlen(pfs)))
146 						*res = true;
147 				}
148 			} else
149 				assert(0);
150 		}
151 		break;
152 	case HAMMER2_BREF_TYPE_INDIRECT:
153 		bscan = &media->npdata[0];
154 		bcount = bytes / sizeof(hammer2_blockref_t);
155 		break;
156 	default:
157 		bscan = NULL;
158 		bcount = 0;
159 		break;
160 	}
161 
162 	for (i = 0; i < bcount; ++i) {
163 		if (bscan[i].type != HAMMER2_BREF_TYPE_EMPTY) {
164 			if (find_pfs(fp, &bscan[i], pfs, res) == -1) {
165 				free(media);
166 				return (-1);
167 			}
168 		}
169 	}
170 	free(media);
171 
172 	return (0);
173 }
174 
175 static char*
176 extract_device_name(const char *devpath)
177 {
178 	char *p, *head;
179 
180 	if (!devpath)
181 		return NULL;
182 
183 	p = strdup(devpath);
184 	head = p;
185 
186 	p = strchr(p, '@');
187 	if (p)
188 		*p = 0;
189 
190 	p = strrchr(head, '/');
191 	if (p) {
192 		p++;
193 		if (*p == 0) {
194 			free(head);
195 			return NULL;
196 		}
197 		p = strdup(p);
198 		free(head);
199 		return p;
200 	}
201 
202 	return head;
203 }
204 
205 static int
206 read_label(FILE *fp, char *label, size_t size)
207 {
208 	hammer2_blockref_t broot, best, *bref;
209 	hammer2_media_data_t *vols[HAMMER2_NUM_VOLHDRS], *media;
210 	size_t bytes;
211 	bool res = false;
212 	int i, best_i, error = 1;
213 	const char *pfs;
214 	char *devname;
215 
216 	best_i = -1;
217 	memset(&best, 0, sizeof(best));
218 
219 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++) {
220 		memset(&broot, 0, sizeof(broot));
221 		broot.type = HAMMER2_BREF_TYPE_VOLUME;
222 		broot.data_off = (i * HAMMER2_ZONE_BYTES64) | HAMMER2_PBUFRADIX;
223 		vols[i] = read_buf(fp, broot.data_off & ~HAMMER2_OFF_MASK_RADIX,
224 		    sizeof(*vols[i]));
225 		broot.mirror_tid = vols[i]->voldata.mirror_tid;
226 		if (best_i < 0 || best.mirror_tid < broot.mirror_tid) {
227 			best_i = i;
228 			best = broot;
229 		}
230 	}
231 
232 	bref = &vols[best_i]->voldata.sroot_blockset.blockref[0];
233 	if (bref->type != HAMMER2_BREF_TYPE_INODE) {
234 		warnx("blockref type is not inode");
235 		goto fail;
236 	}
237 
238 	media = read_media(fp, bref, &bytes);
239 	if (media == NULL) {
240 		goto fail;
241 	}
242 
243 	pfs = "";
244 	devname = extract_device_name(NULL);
245 	assert(!devname); /* Currently always NULL in FreeBSD. */
246 
247 	/* Add device name to help support multiple autofs -media mounts. */
248 	if (find_pfs(fp, bref, pfs, &res) == 0 && res) {
249 		if (devname)
250 			snprintf(label, size, "%s_%s", pfs, devname);
251 		else
252 			strlcpy(label, pfs, size);
253 	} else {
254 		memset(label, 0, size);
255 		memcpy(label, media->ipdata.filename,
256 		    sizeof(media->ipdata.filename));
257 		if (devname) {
258 			strlcat(label, "_", size);
259 			strlcat(label, devname, size);
260 		}
261 	}
262 	if (devname)
263 		free(devname);
264 	free(media);
265 	error = 0;
266 fail:
267 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++)
268 		free(vols[i]);
269 
270 	return (error);
271 }
272 
273 int
274 fstyp_hammer2(FILE *fp, char *label, size_t size)
275 {
276 	hammer2_volume_data_t *voldata;
277 	int error = 1;
278 
279 	voldata = read_voldata(fp);
280 	if (test_voldata(voldata))
281 		goto fail;
282 
283 	error = read_label(fp, label, size);
284 fail:
285 	free(voldata);
286 	return (error);
287 }
288