xref: /titanic_52/usr/src/boot/sys/boot/common/ufsread.c (revision e48f27a0bf5ac8d6bcd05e2d0554b4aab53b1059)
1 /*-
2  * Copyright (c) 2002 McAfee, Inc.
3  * All rights reserved.
4  *
5  * This software was developed for the FreeBSD Project by Marshall
6  * Kirk McKusick and McAfee Research,, the Security Research Division of
7  * McAfee, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as
8  * part of the DARPA CHATS research program
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 /*-
32  * Copyright (c) 1998 Robert Nordier
33  * All rights reserved.
34  *
35  * Redistribution and use in source and binary forms are freely
36  * permitted provided that the above copyright notice and this
37  * paragraph and the following disclaimer are duplicated in all
38  * such forms.
39  *
40  * This software is provided "AS IS" and without any express or
41  * implied warranties, including, without limitation, the implied
42  * warranties of merchantability and fitness for a particular
43  * purpose.
44  */
45 
46 #include <sys/cdefs.h>
47 
48 #include <ufs/ufs/dinode.h>
49 #include <ufs/ufs/dir.h>
50 #include <ufs/ffs/fs.h>
51 
52 #ifdef UFS_SMALL_CGBASE
53 /* XXX: Revert to old (broken for over 1.5Tb filesystems) version of cgbase
54    (see sys/ufs/ffs/fs.h rev 1.39) so that small boot loaders (e.g. boot2) can
55    support both UFS1 and UFS2. */
56 #undef cgbase
57 #define cgbase(fs, c)   ((ufs2_daddr_t)((fs)->fs_fpg * (c)))
58 #endif
59 
60 typedef	uint32_t	ufs_ino_t;
61 
62 /*
63  * We use 4k `virtual' blocks for filesystem data, whatever the actual
64  * filesystem block size. FFS blocks are always a multiple of 4k.
65  */
66 #define VBLKSHIFT	12
67 #define VBLKSIZE	(1 << VBLKSHIFT)
68 #define VBLKMASK	(VBLKSIZE - 1)
69 #define DBPERVBLK	(VBLKSIZE / DEV_BSIZE)
70 #define INDIRPERVBLK(fs) (NINDIR(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
71 #define IPERVBLK(fs)	(INOPB(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
72 #define INO_TO_VBA(fs, ipervblk, x) \
73     (fsbtodb(fs, cgimin(fs, ino_to_cg(fs, x))) + \
74     (((x) % (fs)->fs_ipg) / (ipervblk) * DBPERVBLK))
75 #define INO_TO_VBO(ipervblk, x) ((x) % ipervblk)
76 #define FS_TO_VBA(fs, fsb, off) (fsbtodb(fs, fsb) + \
77     ((off) / VBLKSIZE) * DBPERVBLK)
78 #define FS_TO_VBO(fs, fsb, off) ((off) & VBLKMASK)
79 
80 /* Buffers that must not span a 64k boundary. */
81 struct dmadat {
82 	char blkbuf[VBLKSIZE];	/* filesystem blocks */
83 	char indbuf[VBLKSIZE];	/* indir blocks */
84 	char sbbuf[SBLOCKSIZE];	/* superblock */
85 	char secbuf[DEV_BSIZE];	/* for MBR/disklabel */
86 };
87 static struct dmadat *dmadat;
88 
89 static ufs_ino_t lookup(const char *);
90 static ssize_t fsread(ufs_ino_t, void *, size_t);
91 static uint8_t inode_type(ufs_ino_t inode);
92 
93 static uint8_t ls, dsk_meta;
94 static uint32_t fs_off;
95 
96 #ifndef UFS2_ONLY
97 static struct ufs1_dinode dp1;
98 ufs1_daddr_t addr1;
99 #endif
100 #ifndef UFS1_ONLY
101 static struct ufs2_dinode dp2;
102 #endif
103 static struct fs fs;
104 static ufs_ino_t inomap;
105 static ufs2_daddr_t blkmap, indmap;
106 
107 static __inline uint8_t
108 fsfind(const char *name, ufs_ino_t * ino)
109 {
110 	static char buf[DEV_BSIZE];
111 	struct direct *d;
112 	char *s;
113 	ssize_t n;
114 
115 	fs_off = 0;
116 	while ((n = fsread(*ino, buf, DEV_BSIZE)) > 0)
117 		for (s = buf; s < buf + DEV_BSIZE;) {
118 			d = (void *)s;
119 			if (ls)
120 				printf("%s ", d->d_name);
121 			else if (!strcmp(name, d->d_name)) {
122 				*ino = d->d_ino;
123 				return inode_type(*ino);
124 			}
125 			s += d->d_reclen;
126 		}
127 	if (n != -1 && ls)
128 		printf("\n");
129 	return 0;
130 }
131 
132 static ufs_ino_t
133 lookup(const char *path)
134 {
135 	static char name[UFS_MAXNAMLEN + 1];
136 	const char *s;
137 	ufs_ino_t ino;
138 	ssize_t n;
139 	uint8_t dt;
140 
141 	ino = ROOTINO;
142 	dt = DT_DIR;
143 	for (;;) {
144 		if (*path == '/')
145 			path++;
146 		if (!*path)
147 			break;
148 		for (s = path; *s && *s != '/'; s++);
149 		if ((n = s - path) > UFS_MAXNAMLEN)
150 			return 0;
151 		ls = *path == '?' && n == 1 && !*s;
152 		memcpy(name, path, n);
153 		name[n] = 0;
154 		if (dt != DT_DIR) {
155 			printf("%s: not a directory.\n", name);
156 			return (0);
157 		}
158 		if ((dt = fsfind(name, &ino)) <= 0)
159 			break;
160 		path = s;
161 	}
162 	return dt == DT_REG ? ino : 0;
163 }
164 
165 /*
166  * Possible superblock locations ordered from most to least likely.
167  */
168 static int sblock_try[] = SBLOCKSEARCH;
169 
170 #if defined(UFS2_ONLY)
171 #define DIP(field) dp2.field
172 #elif defined(UFS1_ONLY)
173 #define DIP(field) dp1.field
174 #else
175 #define DIP(field) fs.fs_magic == FS_UFS1_MAGIC ? dp1.field : dp2.field
176 #endif
177 
178 static uint8_t
179 inode_type(ufs_ino_t inode)
180 {
181 	char *blkbuf;
182 	void *indbuf;
183 	size_t n;
184 
185 	blkbuf = dmadat->blkbuf;
186 	indbuf = dmadat->indbuf;
187 
188 	if (!inode)
189 		return (0);
190 	if (inomap != inode) {
191 		n = IPERVBLK(&fs);
192 		if (dskread(blkbuf, INO_TO_VBA(&fs, n, inode), DBPERVBLK))
193 			return (-1);
194 		n = INO_TO_VBO(n, inode);
195 #if defined(UFS1_ONLY)
196 		memcpy(&dp1, (struct ufs1_dinode *)blkbuf + n,
197 		    sizeof(struct ufs1_dinode));
198 #elif defined(UFS2_ONLY)
199 		memcpy(&dp2, (struct ufs2_dinode *)blkbuf + n,
200 		    sizeof(struct ufs2_dinode));
201 #else
202 		if (fs.fs_magic == FS_UFS1_MAGIC)
203 			memcpy(&dp1, (struct ufs1_dinode *)blkbuf + n,
204 			    sizeof(struct ufs1_dinode));
205 		else
206 			memcpy(&dp2, (struct ufs2_dinode *)blkbuf + n,
207 			    sizeof(struct ufs2_dinode));
208 #endif
209 		inomap = inode;
210 		fs_off = 0;
211 		blkmap = indmap = 0;
212 	}
213 	return (IFTODT(DIP(di_mode)));
214 }
215 
216 static ssize_t
217 fsread_size(ufs_ino_t inode, void *buf, size_t nbyte, size_t *fsizep)
218 {
219 	char *blkbuf;
220 	void *indbuf;
221 	char *s;
222 	size_t n, nb, size, off, vboff;
223 	ufs_lbn_t lbn;
224 	ufs2_daddr_t addr2, vbaddr;
225 	u_int u;
226 
227 	/* Basic parameter validation. */
228 	if ((buf == NULL && nbyte != 0) || dmadat == NULL)
229 		return (-1);
230 
231 	blkbuf = dmadat->blkbuf;
232 	indbuf = dmadat->indbuf;
233 
234 	/*
235 	 * Force probe if inode is zero to ensure we have a valid fs, otherwise
236 	 * when probing multiple paritions, reads from subsequent parititions
237 	 * will incorrectly succeed.
238 	 */
239 	if (!dsk_meta || inode == 0) {
240 		inomap = 0;
241 		dsk_meta = 0;
242 		for (n = 0; sblock_try[n] != -1; n++) {
243 			if (dskread(dmadat->sbbuf, sblock_try[n] / DEV_BSIZE,
244 			    SBLOCKSIZE / DEV_BSIZE))
245 				return -1;
246 			memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
247 			if ((
248 #if defined(UFS1_ONLY)
249 			    fs.fs_magic == FS_UFS1_MAGIC
250 #elif defined(UFS2_ONLY)
251 			    (fs.fs_magic == FS_UFS2_MAGIC &&
252 			    fs.fs_sblockloc == sblock_try[n])
253 #else
254 			    fs.fs_magic == FS_UFS1_MAGIC ||
255 			    (fs.fs_magic == FS_UFS2_MAGIC &&
256 			    fs.fs_sblockloc == sblock_try[n])
257 #endif
258 			    ) &&
259 			    fs.fs_bsize <= MAXBSIZE &&
260 			    fs.fs_bsize >= (int32_t)sizeof(struct fs))
261 				break;
262 		}
263 		if (sblock_try[n] == -1) {
264 			return -1;
265 		}
266 		dsk_meta++;
267 	} else
268 		memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
269 	if (!inode)
270 		return 0;
271 	if (inomap != inode) {
272 		n = IPERVBLK(&fs);
273 		if (dskread(blkbuf, INO_TO_VBA(&fs, n, inode), DBPERVBLK))
274 			return -1;
275 		n = INO_TO_VBO(n, inode);
276 #if defined(UFS1_ONLY)
277 		memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
278 		    sizeof(dp1));
279 #elif defined(UFS2_ONLY)
280 		memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
281 		    sizeof(dp2));
282 #else
283 		if (fs.fs_magic == FS_UFS1_MAGIC)
284 			memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
285 			    sizeof(dp1));
286 		else
287 			memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
288 			    sizeof(dp2));
289 #endif
290 		inomap = inode;
291 		fs_off = 0;
292 		blkmap = indmap = 0;
293 	}
294 	s = buf;
295 	size = DIP(di_size);
296 	n = size - fs_off;
297 	if (nbyte > n)
298 		nbyte = n;
299 	nb = nbyte;
300 	while (nb) {
301 		lbn = lblkno(&fs, fs_off);
302 		off = blkoff(&fs, fs_off);
303 		if (lbn < NDADDR) {
304 			addr2 = DIP(di_db[lbn]);
305 		} else if (lbn < NDADDR + NINDIR(&fs)) {
306 			n = INDIRPERVBLK(&fs);
307 			addr2 = DIP(di_ib[0]);
308 			u = (u_int)(lbn - NDADDR) / n * DBPERVBLK;
309 			vbaddr = fsbtodb(&fs, addr2) + u;
310 			if (indmap != vbaddr) {
311 				if (dskread(indbuf, vbaddr, DBPERVBLK))
312 					return -1;
313 				indmap = vbaddr;
314 			}
315 			n = (lbn - NDADDR) & (n - 1);
316 #if defined(UFS1_ONLY)
317 			memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
318 			    sizeof(ufs1_daddr_t));
319 			addr2 = addr1;
320 #elif defined(UFS2_ONLY)
321 			memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
322 			    sizeof(ufs2_daddr_t));
323 #else
324 			if (fs.fs_magic == FS_UFS1_MAGIC) {
325 				memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
326 				    sizeof(ufs1_daddr_t));
327 				addr2 = addr1;
328 			} else
329 				memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
330 				    sizeof(ufs2_daddr_t));
331 #endif
332 		} else
333 			return -1;
334 		vbaddr = fsbtodb(&fs, addr2) + (off >> VBLKSHIFT) * DBPERVBLK;
335 		vboff = off & VBLKMASK;
336 		n = sblksize(&fs, (off_t)size, lbn) - (off & ~VBLKMASK);
337 		if (n > VBLKSIZE)
338 			n = VBLKSIZE;
339 		if (blkmap != vbaddr) {
340 			if (dskread(blkbuf, vbaddr, n >> DEV_BSHIFT))
341 				return -1;
342 			blkmap = vbaddr;
343 		}
344 		n -= vboff;
345 		if (n > nb)
346 			n = nb;
347 		memcpy(s, blkbuf + vboff, n);
348 		s += n;
349 		fs_off += n;
350 		nb -= n;
351 	}
352 
353 	if (fsizep != NULL)
354 		*fsizep = size;
355 
356 	return nbyte;
357 }
358 
359 static ssize_t
360 fsread(ufs_ino_t inode, void *buf, size_t nbyte)
361 {
362 
363 	return fsread_size(inode, buf, nbyte, NULL);
364 }
365 
366