xref: /freebsd/usr.sbin/fstyp/hammer2.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
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 #include <stdio.h>
33 #include <stdlib.h>
34 #include <stdbool.h>
35 #include <string.h>
36 #include <err.h>
37 #include <assert.h>
38 
39 #include <sys/types.h>
40 
41 #include "hammer2_disk.h"
42 
43 #include "fstyp.h"
44 
45 static hammer2_volume_data_t*
46 read_voldata(FILE *fp)
47 {
48 	hammer2_volume_data_t *voldata;
49 
50 	voldata = read_buf(fp, 0, sizeof(*voldata));
51 	if (voldata == NULL)
52 		err(1, "failed to read volume data");
53 
54 	return (voldata);
55 }
56 
57 static int
58 test_voldata(const hammer2_volume_data_t *voldata)
59 {
60 	if (voldata->magic != HAMMER2_VOLUME_ID_HBO &&
61 	    voldata->magic != HAMMER2_VOLUME_ID_ABO)
62 		return (1);
63 
64 	return (0);
65 }
66 
67 static hammer2_media_data_t*
68 read_media(FILE *fp, const hammer2_blockref_t *bref, size_t *media_bytes)
69 {
70 	hammer2_media_data_t *media;
71 	hammer2_off_t io_off, io_base;
72 	size_t bytes, io_bytes, boff;
73 
74 	bytes = (bref->data_off & HAMMER2_OFF_MASK_RADIX);
75 	if (bytes)
76 		bytes = (size_t)1 << bytes;
77 	*media_bytes = bytes;
78 
79 	if (!bytes) {
80 		warnx("blockref has no data");
81 		return (NULL);
82 	}
83 
84 	io_off = bref->data_off & ~HAMMER2_OFF_MASK_RADIX;
85 	io_base = io_off & ~(hammer2_off_t)(HAMMER2_MINIOSIZE - 1);
86 	boff = io_off - io_base;
87 
88 	io_bytes = HAMMER2_MINIOSIZE;
89 	while (io_bytes + boff < bytes)
90 		io_bytes <<= 1;
91 
92 	if (io_bytes > sizeof(hammer2_media_data_t)) {
93 		warnx("invalid I/O bytes");
94 		return (NULL);
95 	}
96 
97 	if (fseek(fp, io_base, SEEK_SET) == -1) {
98 		warnx("failed to seek media");
99 		return (NULL);
100 	}
101 	media = read_buf(fp, io_base, io_bytes);
102 	if (media == NULL) {
103 		warnx("failed to read media");
104 		return (NULL);
105 	}
106 	if (boff)
107 		memcpy(media, (char *)media + boff, bytes);
108 
109 	return (media);
110 }
111 
112 static int
113 find_pfs(FILE *fp, const hammer2_blockref_t *bref, const char *pfs, bool *res)
114 {
115 	hammer2_media_data_t *media;
116 	hammer2_inode_data_t ipdata;
117 	hammer2_blockref_t *bscan;
118 	size_t bytes;
119 	int i, bcount;
120 
121 	media = read_media(fp, bref, &bytes);
122 	if (media == NULL)
123 		return (-1);
124 
125 	switch (bref->type) {
126 	case HAMMER2_BREF_TYPE_INODE:
127 		ipdata = media->ipdata;
128 		if (ipdata.meta.pfs_type == HAMMER2_PFSTYPE_SUPROOT) {
129 			bscan = &ipdata.u.blockset.blockref[0];
130 			bcount = HAMMER2_SET_COUNT;
131 		} else {
132 			bscan = NULL;
133 			bcount = 0;
134 			if (ipdata.meta.op_flags & HAMMER2_OPFLAG_PFSROOT) {
135 				if (memchr(ipdata.filename, 0,
136 				    sizeof(ipdata.filename))) {
137 					if (!strcmp(
138 					    (const char*)ipdata.filename, pfs))
139 						*res = true;
140 				} else {
141 					if (strlen(pfs) > 0 &&
142 					    !memcmp(ipdata.filename, pfs,
143 					    strlen(pfs)))
144 						*res = true;
145 				}
146 			} else
147 				assert(0);
148 		}
149 		break;
150 	case HAMMER2_BREF_TYPE_INDIRECT:
151 		bscan = &media->npdata[0];
152 		bcount = bytes / sizeof(hammer2_blockref_t);
153 		break;
154 	default:
155 		bscan = NULL;
156 		bcount = 0;
157 		break;
158 	}
159 
160 	for (i = 0; i < bcount; ++i) {
161 		if (bscan[i].type != HAMMER2_BREF_TYPE_EMPTY) {
162 			if (find_pfs(fp, &bscan[i], pfs, res) == -1) {
163 				free(media);
164 				return (-1);
165 			}
166 		}
167 	}
168 	free(media);
169 
170 	return (0);
171 }
172 
173 static char*
174 extract_device_name(const char *devpath)
175 {
176 	char *p, *head;
177 
178 	if (!devpath)
179 		return NULL;
180 
181 	p = strdup(devpath);
182 	head = p;
183 
184 	p = strchr(p, '@');
185 	if (p)
186 		*p = 0;
187 
188 	p = strrchr(head, '/');
189 	if (p) {
190 		p++;
191 		if (*p == 0) {
192 			free(head);
193 			return NULL;
194 		}
195 		p = strdup(p);
196 		free(head);
197 		return p;
198 	}
199 
200 	return head;
201 }
202 
203 static int
204 read_label(FILE *fp, char *label, size_t size)
205 {
206 	hammer2_blockref_t broot, best, *bref;
207 	hammer2_media_data_t *vols[HAMMER2_NUM_VOLHDRS], *media;
208 	size_t bytes;
209 	bool res = false;
210 	int i, best_i, error = 1;
211 	const char *pfs;
212 	char *devname;
213 
214 	best_i = -1;
215 	memset(&best, 0, sizeof(best));
216 
217 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++) {
218 		memset(&broot, 0, sizeof(broot));
219 		broot.type = HAMMER2_BREF_TYPE_VOLUME;
220 		broot.data_off = (i * HAMMER2_ZONE_BYTES64) | HAMMER2_PBUFRADIX;
221 		vols[i] = read_buf(fp, broot.data_off & ~HAMMER2_OFF_MASK_RADIX,
222 		    sizeof(*vols[i]));
223 		broot.mirror_tid = vols[i]->voldata.mirror_tid;
224 		if (best_i < 0 || best.mirror_tid < broot.mirror_tid) {
225 			best_i = i;
226 			best = broot;
227 		}
228 	}
229 
230 	bref = &vols[best_i]->voldata.sroot_blockset.blockref[0];
231 	if (bref->type != HAMMER2_BREF_TYPE_INODE) {
232 		warnx("blockref type is not inode");
233 		goto fail;
234 	}
235 
236 	media = read_media(fp, bref, &bytes);
237 	if (media == NULL) {
238 		goto fail;
239 	}
240 
241 	pfs = "";
242 	devname = extract_device_name(NULL);
243 	assert(!devname); /* Currently always NULL in FreeBSD. */
244 
245 	/* Add device name to help support multiple autofs -media mounts. */
246 	if (find_pfs(fp, bref, pfs, &res) == 0 && res) {
247 		if (devname)
248 			snprintf(label, size, "%s_%s", pfs, devname);
249 		else
250 			strlcpy(label, pfs, size);
251 	} else {
252 		memset(label, 0, size);
253 		memcpy(label, media->ipdata.filename,
254 		    sizeof(media->ipdata.filename));
255 		if (devname) {
256 			strlcat(label, "_", size);
257 			strlcat(label, devname, size);
258 		}
259 	}
260 	if (devname)
261 		free(devname);
262 	free(media);
263 	error = 0;
264 fail:
265 	for (i = 0; i < HAMMER2_NUM_VOLHDRS; i++)
266 		free(vols[i]);
267 
268 	return (error);
269 }
270 
271 int
272 fstyp_hammer2(FILE *fp, char *label, size_t size)
273 {
274 	hammer2_volume_data_t *voldata;
275 	int error = 1;
276 
277 	voldata = read_voldata(fp);
278 	if (test_voldata(voldata))
279 		goto fail;
280 
281 	error = read_label(fp, label, size);
282 fail:
283 	free(voldata);
284 	return (error);
285 }
286